diff --git a/src/patterns/data/default/ExtendedDescription.tsv b/src/patterns/data/default/ExtendedDescription.tsv new file mode 100644 index 000000000..53d9b7518 --- /dev/null +++ b/src/patterns/data/default/ExtendedDescription.tsv @@ -0,0 +1,457 @@ +defined_class CL_short_form desc pubs +CL:0002538 CL_0002538 "Intrahepatic cholangiocytes represent a subset of the biliary epithelial cells that form a network of tubes in the liver called the biliary tree The intrahepatic cholangiocytes reside specifically in the intrahepatic bile ducts and play a crucial role in liver physiology and bile production and secretion, thereby aiding in the digestion and absorption of fats in the small intestine. These specific cholangiocytes arise from bipotent hepatoblasts, whereas extrahepatic cholangiocytes share an embryologic origin with the ventral pancreas. + +Recent research suggests that there is also heterogeneity within populations of intrahepatic cholangiocytes with different transcriptional profiles, proliferative capacity, and biological function; for example, subpopulations differ in calcium-mobilizing receptors. + +The primary function of intrahepatic cholangiocytes is related to bile formation and maintenance of its flow. In addition to their secretory and absorptive activities, they are involved in the regulation of bile composition, volume, and alkalinization, contributing to the neutralization of the acidic chyme (partly digested food) that enters the intestine from the stomach. Intrahepatic cholangiocytes are also recognized for their role in liver regeneration and repair, often proliferating in response to injury. + +Intrahepatic cholangiocytes take part in certain pathological conditions, like primary biliary cirrhosis and cholangiocarcinoma. Changes in these cells often lead to abnormalities in bile formation and transport, causing cholestatic liver diseases. Overall, the primary and secondary functional activities of intrahepatic cholangiocytes are vital in maintaining liver function, digestive processes, and contributing to the body's response to liver injury. + +" DOI:10.1016/j.gastha.2022.07.015|DOI:10.1016/j.ajpath.2023.02.012|DOI:10.1002/hep.31252|DOI:10.1016/j.biocel.2010.06.020 +CL:0002543 CL_0002543 "Vein endothelial cells form a thin layer of squamous cells, the endothelium, lining the interior surface of veins throughout the body. They shape the inner cellular lining of the entire vascular system, including the heart, playing a crucial role in blood circulation. The unique characteristic compact arrangement of these cells enables veins to act as a barrier between the blood (that can contain foreign substances) and the surrounding venous tissue and maintain the integrity of the vascular system. + +The primary function of vein endothelial cells is to control the exchange of substances between the bloodstream and the surrounding tissues. They facilitate selective transportation of molecules depending on their size and solubility, including gases, nutrients, hormones, and waste products. Vein endothelial cells also play a protective role by inhibiting the translocation of toxins or pathogens from blood to tissues. Additionally, these cells are involved in blood coagulation and inflammation response, primarily by producing substances that inhibit blood clot formation under normal conditions and initiating clotting when necessary. + +Another significant function of vein endothelial cells is the regulation of blood flow and blood pressure. They produce and release several substances, including nitric oxide and prostacyclin, which help in controlling vasodilation and vasoconstriction, thereby regulating blood pressure. These cells are also responsible for angiogenesis, the formation of new blood vessels, which is crucial during wound healing and in the formation of granulation tissue. Consequently, any dysfunction in vein endothelial cells can lead to severe health problems like atherosclerosis, hypertension, and thrombosis. +" DOI:10.1038/s41569-022-00770-1|DOI:10.1007/s00441-008-0706-5|DOI:10.3390/ijms20184411|DOI:10.1038/s41598-021-01360-w +CL:0002573 CL_0002573 "Schwann cells, also known as neurolemmocytes, are a type of glial cell located in the peripheral nervous system. These cells play a significant role in the healthy functioning of nerves by producing myelin, a fatty substance that forms a coating around nerve fibers. Myelin serves as an insulator and enhances the speed and efficiency of electrical nerve impulses; a single Schwann cell can myelinate a single axon. Myelination starts by the elongation and envelopment of the Schwann cell around the axon, followed by the synthesis and deposition of myelin layers. Some studies suggest that Schwann cells may regulate neuronal action potential, muscular contraction, and the sensitive response. + +While Schwann cells are most commonly known for the formation of the myelin sheath, some Schwann cells do not form myelin: Remak Schwann cells, a class of nonmyelinating Schwann cells, ensheath axons with smaller diameter, such as C fiber nociceptors in sciatic nerves and form Remak bundles. + +Schwann cells are found along both motor and sensory neurons and are crucial for the advancement and recovery of peripheral nerve injuries, due to their capacity to support nerve regeneration. In cases of nerve injury, Schwann cells play a vital role in recovery by initiating Wallerian degeneration, a process in which the part of the axon distal to the injury site degrades and is then cleared away. Following this, Schwann cells can guide the regrowth of the nerve, providing a conducive environment for axon regeneration. They remodel themselves into a regenerative phenotype, proliferate, and organize themselves into bands of Büngner that provide physical and chemical guidance for the regrowths of axons. This function of Schwann cells in the repair and regeneration of nervous system highlights their therapeutic potential in peripheral nerve injury treatments." DOI:10.1016/j.biocel.2006.05.007|DOI:10.1016/B978-0-444-52902-2.00005-9|DOI:10.1186/1742-2094-8-110|DOI:10.1002/glia.23892|DOI:10.1186/s13064-020-00140-y +CL:0002585 CL_0002585 "Retinal blood vessel endothelial cells constitute the innermost lining of the blood vessels found in the retina, the light-sensitive layer of tissue at the back of the eye. The primary role of these cells revolves around their location within the retinal vascular system, forming the structure of the blood-retinal barrier, a subset of the larger blood-ocular barrier system. + +The endothelial cells are particularly involved in the growth of new retinal blood vessels from pre-existing ones (angiogenesis); this is critical in managing the amount of oxygen and essential nutrients delivered to the ocular tissues. They are crucial for maintaining homeostasis in the retinal environment by controlling the exchange of molecules between the blood and the retina. Furthermore, they mediate immune cell trafficking, supporting the immune privilege of the eye by preventing the unrestricted infiltration of inflammatory cells into the retina, thus maintaining ocular health and normal vision. + +The malfunction or dysfunction of retinal blood vessel endothelial cells is implicated in numerous ocular pathologies, particularly diabetic retinopathy, which is one of the leading causes of blindness worldwide. In such conditions, the compromise in the integrity of the blood-retinal barrier and excess angiogenesis can lead to retinal edema and pathological neovascularization, resulting in vision loss. +" DOI:10.5301/EJO.2010.6049|DOI:10.1038/nature04482|DOI:10.1016/j.preteyeres.2012.08.004|DOI:0.1016/j.preteyeres.2015.08.001 +CL:0002618 CL_0002618 "Endothelial cells of the umbilical vein form the inner lining of the veins found in the umbilical cord. They are involved in tube formation and migration which are essential for angiogenesis, the process of generating new blood vessels; this is critical during the fetal stage for the development of the circulatory system. Endothelial cells of the umbilical vein also play a role in controlling the passage of white blood cells into tissues during inflammatory responses. + +Because human umbilical vein endothelial cells (HUVECs) can easily be derived from the umbilical cord, and because they express common endothelial cell markers, they have been used as an epithelial cell model for studies on cell proliferation, migration, angiogenesis, and inflammation. They have been used as models for vascular diseases like atherosclerosis, for investigating how tumor cells infiltrate blood vessels and form metastases. + +Thus, while endothelial cells of the umbilical vein play a critical role in vascular biology, they also represent a powerful tool in disease studies and potential treatment strategies. + +" DOI:10.1172/JCI107470|DOI:10.3390/app10030938|DOI:10.1002/cyto.a.20952|DOI:10.1007/s12015-006-0015-x|https://www.ncbi.nlm.nih.gov/books/NBK53254/ +CL:0002671 CL_0002671 "Endothelial stalk cells are specialized vascular cells vital in angiogenesis, a process through which new blood vessels are formed from pre-existing ones; specifically, endothelial stalk cells are involved in sprouting angiogenesis, where they help form the body of new blood vessels. + +Vascular sprouting relies on the coordinated activity of migrating endothelial tip cells at the forefront and proliferating stalk cells that elongate the sprout. The process is tightly controlled by different growths factors: Vascular Endothelial Growth Factor acts on endothelial cells, inducing them to become endothelial tip cells that initiate sprouting. After sprouting initiation, activation of Notch signaling suppresses differentiation toward a tip cell phenotype and some of the endothelial cells differentiate into stalk cells, which follow tip cells, multiply, and elongate to provide a structural backbone to the growing vessel sprout. + +In contrast to endothelial tip cells, which migrate and lead the angiogenic sprout, endothelial stalk cells behind the sprouts continue forming the tube or lumen for blood flow and facilitate maturation and stability of the new vessel. The delicate balance between the activities of stalk and tip cells during angiogenesis is crucial to build a functional vascular network. Dysfunctions in endothelial stalk cells can lead to pathological conditions such as impaired wound healing, unregulated tumor growth, and metastasis due to abnormal angiogenesis. +" DOI:10.1101/cshperspect.a006569|DOI:10.1007/s12079-019-00511-z|DOI:10.1016/j.cmet.2013.08.001|DOI:10.3389/fcell.2021.642352 +CL:0005009 CL_0005009 "Renal principal cells are the major cell type in the initial collecting tubule and the cortical and outer medullary collecting ducts, as well as the connecting tubule, in the nephrons of the kidneys. + +A key function of renal principal cells is the regulation of water balance in the body. These cells express aquaporin-2 (AQP2) water channels, which facilitate the reabsorption of water from the fluid within the renal tubule lumen back into the blood. The translocation of AQP2 to the cell membrane is controlled by the hormone vasopressin: In response to high vasopressin levels, AQP2 moves to the cell membrane, allowing water to pass through effectively and be reabsorbed, therefore concentrating the urine. Conversely, in low vasopressin conditions, AQP2 is removed from the membrane, reducing water reabsorption and diluting the urine. + +Renal principal cells are also involved in the regulation of sodium and potassium levels in the body. They have sodium channels (ENaC) in their luminal membranes which permit the reabsorption of sodium ions from the tubule fluid back into the blood, resulting in a net reabsorption of sodium ions into the systemic circulation. This process is controlled, in part, by the hormone aldosterone. Additionally, renal principal cells contain potassium channels that facilitate the secretion of potassium ions into the urine. The activities of these channels, in coordination with other cell types in the nephron, are critical for maintaining electrolyte balance and overall body homeostasis." DOI:10.2215/CJN.05760513|DOI:10.1016/j.krcp.2013.07.005|DOI:10.2215/CJN.08580813 +CL:0005011 CL_0005011 "Renal alpha-intercalated cells are located within the connecting tubules and collecting ducts of the kidneys, which are components of the kidney's complex nephron system. Along with beta-intercalated cells, they play a critical role in the body’s acid-base balance. + +Renal alpha-intercalated cells contain an abundance of proton pumps and enzymes like carbonic anhydrase, which aid in the transport of hydrogen ions for secretion in the urine. The bicarbonate/chloride transporters on their apical membrane meanwhile take up bicarbonate ions from the urine and supply them back into the blood. Through this mechanism, these cells contribute significantly to the neutrality of blood pH, and dysfunction of renal alpha-intercalated cells often leads to distal renal tubular acidosis, a condition resulting in acidic blood and alkaline urine. +" DOI:10.1152/physiol.00008.2011|DOI:10.3390/diseases2020071|DOI:10.1016/j.semnephrol.2019.04.005|DOI:10.1172/JCI63492 +CL:0005019 CL_0005019 "Pancreatic epsilon cells are a specialized type of endocrine cell found in the islets of Langerhans, a region of the pancreas responsible for hormone production. These clusters of cells constitute only about 1% of the pancreatic islet cell population, making them a relatively small yet significant component of the pancreas. Pancreatic epsilon cells have a round or ovoid shape with occasional cytoplasmic extensions and are characterized by small and spherical granules. + +The principal function of pancreatic epsilon cells involves the synthesis and release of the hormone ghrelin, a peptide hormone predominantly produced in the stomach; pancreatic epsilon cells are one of the few sites outside the gastrointestinal tract known to produce this hormone. Ghrelin has multiple vital roles, playing a significant part in generating hunger sensations, promoting fat storage, and influencing various metabolic processes. It also stimulates the release of Growth Hormone (GH) from the anterior pituitary gland. + +During fetal development, when they form a layer around the islet, epsilon cells are an important source of ghrelin, likely secreting the hormone into the circulation; their numbers decrease in adults. While research on pancreatic epsilon cells is still ongoing, these cells have been implicated in several disease states, most notably Type 2 diabetes and metabolic syndrome. The dysfunction or reduction in the number of pancreatic epsilon cells can lead to anomalies in ghrelin production, impacting overall metabolic homeostasis and glucose regulation. +" DOI:10.1210/en.2018-00833|DOI:10.3390/ijms20081867|DOI:10.1007/s00125-008-1238-y|DOI:10.3389/fendo.2022.904004|DOI:10.1152/physrev.00012.2004 +CL:0005010 CL_0005010 "Renal intercalated cells are specialized cells located in the collecting duct system of the kidneys. The primary role of intercalated cells is to reabsorb bicarbonate ions and secrete hydrogen ions, thereby maintaining the acid-base homeostasis in the blood. They comprise two main subtypes primarily distinguished by their functional and morphological attributes: alpha and beta intercalated cells. + +Alpha intercalated cells are more predominant when the body is in a state of acidosis, a condition characterized by an increased acidity of the blood. These cells are specialized in secreting excessive hydrogen ions into the urine through a mechanism involving vacuolar H+-ATPase and H+/K+-ATPase pumps on their apical membranes. They simultaneously reabsorb bicarbonate ions from the tubular fluid and return them to the bloodstream via mechanisms involving carbonic anhydrase II and bicarbonate/chloride exchangers on the basolateral membrane. This dual process helps to increase blood pH towards normal levels. + +When the body is in a state of alkalosis, a condition characterized by lowered levels of hydrogen ions in the blood, beta intercalated cells are more predominant. They primarily reabsorb hydrogen ions from the tubular fluid through vacuolar H+-ATPase and H+/K+-ATPase pumps on their basolateral membranes, while secreting bicarbonate ions into the urine via pendrin, a bicarbonate/chloride exchanger in the apical membrane. These mechanisms work together to decrease blood pH towards normal levels. + +In summary, renal intercalated cells play a critical role in the delicate balance of the body’s pH, safeguarding the body from potential harm caused by acidemia or alkalemia. +" DOI:10.2215/CJN.08880914|DOI:10.1152/ajprenal.2000.279.1.F195|DOI:10.1161/HYPERTENSIONAHA.121.16492|DOI:10.1681/ASN.V1011 +CL:0005026 CL_0005026 "Hepatoblasts are immature precursor cells that predominate during the early stages of liver development, specifically in the embryonic phase of life. They first arise from the endoderm, one of the three primary germ layers in the very early embryo, and then differentiate into two distinct mature liver cell types - the hepatocytes and cholangiocytes. + +During liver organogenesis hepatoblasts proliferate and migrate into the septum transversum to form the liver bud. Proliferation and differentiation of these cells are regulated by several soluble factors, such as hepatocyte growth factor, which is a mitogen of both hepatoblasts and mature hepatocytes. As they start to differentiate into hepatocytes and cholangiocytes, the cells begin to express hepatic markers like albumin and alpha-fetoprotein. + +Although hepatoblasts are specified embryonic liver cells that are bipotential for hepatocytes and cholangiocytes, a subset of liver cells (called oval cells) has been identified in adults that express stem cell markers, such as CD133 and cKIT, and has been suggested to have the same potential as hepatoblasts to differentiate into hepatocytes and cholangiocytes. +" DOI:10.1242/dev.114215|DOI:10.5966/sctm.2015-0051|DOI:10.1016/j.stem.2014.04.010|DOI:10.1093/jb/mvr001|DOI:10.1242/dev.031369 +CL:0009043 CL_0009043 "Intestinal crypt stem cells of the colon, also known as colon crypt base columnar (CBC) cells, are highly specialized cells primarily responsible for the constant self-renewal of the colonic epithelium. These cells are found in the crypts of Lieberkühn - deeply invaginated sections of the colon's mucosal layer. + +The prime function of intestinal crypt stem cells of the colon is to serve as the source of constant cell regeneration in the colon. Every few days, these stem cells divide and differentiate into the various other types of intestinal cells, such as enterocytes, goblet cells, and enteroendocrine cells. + +A constant renewal cycle is necessary due to the harsh environment of the colon where cells continuously encounter abrasive food matter and potential pathogens, leading to a high turnover rate. When the colon's mucosal layer suffers damage, a rapid response is triggered whereby colon crypt stem cells divide faster and are directed to injured sites to repair the epithelial layer. Dysregulation of these cells' function or proliferation can contribute to disorders such as colorectal cancer. + +" DOI:10.1038/s41575-018-0081-y|DOI:10.1186/s12943-019-0962-x|DOI:10.1016/j.cell.2013.07.004|DOI:10.1073/pnas.1607327113|DOI:10.1111/j.1365-2184.2009.00642.x +CL:0009017 CL_0009017 "Intestinal crypt stem cells of the small intestine are a type of adult stem cell intimately involved in the continuous replenishment of the intestinal epithelium, the innermost layer of the intestine responsible for nutrient absorption. These cells, located within the crypts of Lieberkühn, are the origin of various cell lineages that make up the functional units of the small intestine. They possess self-renewal ability, an essential feature of stem cells, which allows them to maintain a steady population in the small intestine. + +One of the critical roles of intestinal crypt stem cells is to drive the continual renewal process taking place in the small intestine every 3-5 days. By proliferating intensively, these cells produce transient amplifying (TA) cells that are characterized by quick division and progressive differentiation. These cells eventually differentiate into specialized cell types, encompassing absorptive enterocytes, mucin-secreting goblet cells, hormone-secreting enteroendocrine cells, and Paneth cells, all of which have essential roles in digestion and nutrient absorption in the small intestine. + +Intestinal crypt stem cells of the small intestine are also play a significant part in injury recovery. Under regular conditions, these cells primarily exist in an active state, facilitating the constant renovation of the gut lining. However, upon injury or loss of regular intestinal crypt stem cells reserve intestinal stem cells, a slow-cycling and radio-resistant population, can be stimulated to take over the duties of active crypt stem cells. Such plasticity provides a powerful regenerative mechanism that ensures the intestinal epithelium's function and structural integrity amidst diverse conditions. +" DOI:10.1038/s41575-018-0081-y|DOI:10.1073/pnas.1607327113|DOI:10.1016/j.celrep.2020.107952 +CL:0011012 CL_0011012 "Neural crest cells are a group of transient and highly migratory cells that originate from the neuroectoderm during the early stages of embryonic development. They are multipotent cells with an exceptional degree of plasticity, capable of differentiating into various somatic cell types and therefore play a fundamental role in the formation of various organs and tissues, making them critical contributors to the developing embryo. + +After the initiation of neurulation (the formation of the neural tube) neural crest cells start to undergo epithelial-to-mesenchymal transition and delaminate and migrate from the dorsal neural tube to several regions throughout the embryo. They differentiate into a range of diverse cell types, such as neurons and glial cells of the peripheral nervous system, including sensory and autonomic neurons. They also contribute to the formation of adrenal glands, pigment cells in the skin (melanocytes), cardiac structures, including parts of the heart septum and major arteries, as well as bones and cartilage of the face and skull. + +Disorders or aberrations in the development or migration of the neural crest cells can lead to serious congenital malformations, such as neurocristopathies, including Hirschsprung disease, neuroblastoma, and neurofibromatosis. " https://doi.org/10.1016/j.ydbio.2011.12.042|DOI:10.3389/fcell.2020.00635/full|DOI:10.1002/dvg.23276|DOI:10.1242/dev.193193 +CL:1000334 CL_1000334 "Enterocytes of the epithelium of the small intestine are specialized cells that reside in the lining of the small intestine, and are primarily responsible for the essential process of nutrient absorption. These cells are columnar epithelial cells with an apical surface lined with microvilli, a feature referred to as the 'brush border', to maximize the surface area available for absorption. + +Enterocytes play a critical role in both the digestion and absorption of nutrients from food. Their extensive brush border contains enzymes that further assist in nutrient breakdown and transport proteins that transfer nutrients, such as glucose, amino acids, lipids, and vitamins, across the cell membrane. + +The enterocytes of the small intestine also participate in the barrier function of the gut lining. Enterocytes are connected by tight junctions, which act as a primary defense line against pathogenic invasion by maintaining intestinal barrier integrity. Additionally, their cell surface is coated in glycocalyx and mucus which forms a defensive barrier preventing the penetration of harmful bacteria into the systemic circulation. " DOI:10.3389/fphys.2021.699152/full|DOI:10.1084/jem.20191130|DOI:10.1038/nri3738|DOI:10.1038/nrgastro.2013.35 +CL:1000347 CL_1000347 "Enterocytes of the colon are specialized epithelial cells located in the lining of the colon, the largest part of the large intestine. These cells play a critical role in absorbing water, electrolytes, and certain vitamins from the food material passed on from the small intestine. With a unique structure of finger-like protrusions referred to as microvilli, the enterocytes increase their surface area for effective absorption. The colon is the last part of the digestive system, and as such, it is responsible for compacting undigested food materials and forming fecal matter. Enterocytes of the colon facilitate this process effectively through absorption of water. + +Enterocytes are known for their high regeneration potential, replenishing every 4-5 days, enabling the healthy functioning of the colon. They originate from stem cells located in the crypt of the colon and differentiate into mature enterocytes as they migrate upwards towards the luminal surface. This constant turnover aids in maintaining the intestinal barrier, preventing the entry of detrimental substances into the systemic circulation. Their tight junctions with other epithelial cells provide a robust barrier against invasive pathogens. + +Enterocytes of the colon are involved in the communication with the gut microbiota. These cells harbor enzymes necessary for the metabolism of short-chain fatty acids, which are the byproducts of the fermentation process by gut bacteria. Short-chain fatty acids serve as a major energy source for colonocytes and are important for maintaining colonic health. The dysfunction of enterocytes, therefore, could lead to disorders such as inflammatory bowel disease or colorectal cancer." DOI:10.1084/jem.20191130|DOI:10.1038/nri3738|DOI:10.1038/nrgastro.2013.35|DOI:10.3389/fimmu.2019.00277|DOI:10.1007/s11894-010-0130-3 +CL:1000342 CL_1000342 "Enterocytes of the epithelium proper of the ileum, commonly known as ileal enterocytes, are specialized epithelial cells found lining the inner surface of the ileum, the final section of the small intestine in the human body. They play a pivotal role in nutrient absorption, digestive metabolic functions, and the maintenance of the host’s immune response. + +Like enterocytes in other parts of the intestine, ileal enterocytes exhibit distinct characteristics specific to their function and role. They have microvilli on their apical surfaces to increase absorption and are important in the absorption of vitamins and the reabsorption of bile salts. These cells also produce enzymes that metabolize lipids and xenobiotics." DOI:10.1084/jem.20191130|DOI:10.1038/nri3738|DOI:10.1111/j.1365-2249.2011.04523.x +CL:1000436 CL_1000436 "Epithelial cells of the lacrimal sac play a significant role in the physiology of tear drainage, acting as an integral part of the lacrimal drainage system. The lacrimal sac is part of the nasolacrimal duct system, a conduit which connects the eye to the nasal cavity, and is lined by multilayered, non-keratinizing, squamous epithelial cells. + +The epithelial cells of the lacrimal sac are specialized for the purpose of maintaining a moist environment and protecting the surface of the eye. They form a barrier that traps and removes potential contaminants from the tear film during the drainage process. These cells also actively contribute to tear turnover by expediting the drainage of excess tears. Dysfunctional epithelial cells of the lacrimal sac can lead to dacryocystitis, a condition characterized by inflammation of the lacrimal sac. + +Epithelial cells of the lacrimal sac also perform various other tasks which ensure the overall health of the eye. They are involved in the regulation of immune responses within the lacrimal apparatus and may have a possible role in host-microbiome interactions. Thus, epithelial cells of the lacrimal sac play a multifaceted role in tear drainage and ocular surface defence, directly translating to eye health and vision quality. +" DOI:10.1007/s004290050160|DOI:10.2147/OPTH.S26048|DOI:10.1111/j.1442-9071.2012.02818.x|DOI:10.1167/tvst.8.4.32|DOI:10.3389/fimmu.2022.918619 +CL:1000413 CL_1000413 "Endothelial cells of the artery, also referred to as arterial endothelial cells, form an integral part of the arterial system. They form a single layer, known as the endothelium, lining the interior surface of arteries, and are able to respond to the high-pressure and flow conditions present in arteries. The primary role of these cells is to provide a barrier between the vessel wall and the blood, exhibiting selective permeability to regulate the movement of liquids, gases, and blood-borne substances across the vascular wall. + +Arterial endothelial cells significantly contribute to maintaining vascular homeostasis. They are at the forefront of sensations and responses to mechanical stimuli, like shear stress and blood pressure changes. An additional key function pertains to the production of nitric oxide, which helps to regulate vascular tone and blood pressure, prevents platelet aggregation, limits leukocyte adhesion to the endothelium, and inhibits smooth muscle cell proliferation. These varied but connected functions help to preclude the development of atherosclerosis, ensuring normal circulation and arterial health. + +Moreover, these cells play a pivotal role in inflammation and coagulation processes. During inflammatory events, they express various adhesion molecules, aiding in leukocyte recruitment and rolling onto the vessel walls for immune response. They also produce anticoagulant and procoagulant substances, involved in blood clotting and clot dissolution, respectively. Dysregulation of the usual functions of arterial endothelial cells can result in serious pathophysiological conditions, such as atherosclerosis, hypertension, and other cardiovascular diseases. +" DOI:10.1007/s10456-021-09785-7|DOI:10.1016/j.ccm.2021.08.005|DOI:10.1007/s00441-008-0706-5|DOI:10.1177/153857440303700107|DOI:10.1016/j.jvs.2004.03.043 +CL:1000454 CL_1000454 "Kidney collecting duct epithelial cells are a specialized type of cells that form an integral part of the renal system. Located in the collecting duct system of the kidneys, these cells are responsible for one of the final steps in the process of urine formation, and they are instrumental in the fine tuning of the volume and composition of urine by reabsorbing water and certain solutes back into the bloodstream. + +These cells express specific channels and carriers that actively and passively transport ions and water. They also have channels on their membranes, such as sodium channels and potassium channels, involved in reabsorbing or secreting these electrolytes depending upon the body's needs. The function of renal collecting duct epithelial cells can be regulated by a variety of hormones, including vasopressin (antidiuretic hormone), which can modulate the ion channels and carriers and hence indirectly influence body fluid homeostasis. + +Aside from their function in ion and water balance, kidney collecting duct epithelial cells also aid in maintaining the body's acid-base balance. They have specialized functionality to secret hydrogen ions into the tubular lumen, which contributes to acid excretion. Any dysfunction may have serious implications and lead to various renal or systemic diseases, exemplifying the importance of these cells in maintaining overall body homeostasis. +" DOI:10.2215/CJN.08880914|DOI:10.2215/CJN.05760513|DOI:10.1016/j.semnephrol.2019.04.005|DOI:10.1016/j.ajpath.2014.01.014 +CL:1000488 CL_1000488 "Cholangiocytes, also known as biliary epithelial cells, are specialized epithelial cells that line the biliary tract, which constitutes the gall bladder and bile ducts inside the liver. Crucial to the maintenance of the liver's health and function, cholangiocytes have a key role in the modification and secretion of bile, a fluid produced by hepatocytes that is essential to digestion and the absorption of fats and vitamins. + +Cholangiocytes accomplish their primary function through the expression of a variety of transport proteins located on their apical and basolateral membranes, which propel bile acids and other contents of the bile into the biliary lumen. The hepatic bile, once secreted by the hepatocytes, is further modified by cholangiocytes via secretion and absorption processes. These processes help in the regulation of bile volume and composition, which is fundamental in ensuring the efficient digestion of dietary fats and fat-soluble vitamins and the excretion of cholesterol. + +In addition to their role in bile modification, cholangiocytes also perform several other integral functions. For instance, these cells express Toll-like receptors (TLRs) which allow cholangiocytes to initiate an immune response against pathogens in the biliary lumen. When functioning normally, these cells contribute to biliary integrity, hepatic architecture, and overall hepatic physiology. However, when they become pathological, they are involved in the progression of liver diseases, such as primary biliary cirrhosis and cholangiocarcinoma – the malignancy of the biliary tract. +" DOI:10.1038/s41575-019-0125-y|DOI:10.1016/j.jcmgh.2015.05.005|DOI:10.1016/j.jhep.2012.10.011|DOI:10.1152/ajpgi.00227.2012|DOI:10.5009/gnl16033 +CL:1000493 CL_1000493 "Mesothelial cells of visceral pleura are specialized epithelial cells that line the inner layer of the pleura, the membrane that envelops the lungs. Positioned adjacent to the lung tissue, these cells form a protective barrier and contribute to the structure of the visceral pleura. They are characterized by their cuboidal to squamous epithelial shape and the presence of microvilli on their surface, a feature aiding in fluid and solute exchange between the pleura and the lungs. + +The primary function of mesothelial cells of visceral pleura is to secrete a lubricating serous fluid to facilitate smooth, frictionless lung movement within the thoracic cavity during respiration. This helps in the prevention of trauma or damage stemming from the constant rubbing of the lung tissue against the chest wall, hence playing a pivotal role in maintaining respiratory function. Besides fluid secretion, these cells have an essential role in the transportation of fluids and particles across the pleura, as well as in inflammation, wound healing, and tissue repair processes within the pleura. + +Mesothelial cells of visceral pleura are notably implicated in the development of pleural diseases such as pleural effusion and pleural mesothelioma, a rare and aggressive form of cancer primarily linked with exposure to asbestos. Alterations, such as hyperplasia or metaplasia, may occur in these mesothelial cells under pathological conditions. +" DOI:10.1016/S1357-2725(03)00242-5|DOI:10.3390/jdb7020007|DOI:10.1152/physrev.00026.2003|DOI:10.1371/journal.pone.0276978|DOI:10.3389/fphys.2014.00221 +CL:1000491 CL_1000491 "Mesothelial cells of the pleura form a significant part of the pleural membrane, a thin, double-layered serous membrane that lines the thoracic cavity and encompasses the lungs. These specialized cells contribute to the pleura's key function of producing a lubricating serous fluid, which reduces friction between the lung's outer surface (visceral pleura) and the inner lining of the thoracic cavity (parietal pleura) during respiration. + +The cellular structure of mesothelial cells, characterized by microvilli on their surface, aids in the secretion and absorption of the pleural fluid, effectively supporting the smooth expansion and contraction of the lungs. Dysregulation in mesothelial cells can lead to pathologies, including pleural effusion and malignant mesothelioma. + +Mesothelial cells of the pleura display unique immunologic properties. They act as a first line of defense against infection because they are able to recognize pathogens and respond by secreting various cytokines and chemokines. Additionally, these cells are directly involved in the translocation of immune cells into the pleural cavity during inflammatory response, thereby playing an active role in the immune response within the pleural environment. + +In the event of pleural injury, these cells are also involved in the mesothelial-mesenchymal transition, a process that allows mesothelial cells to transdifferentiate into myofibroblasts and promote tissue repair. +" DOI:10.1016/j.ccm.2021.08.005|DOI:10.1152/ajplung.90587.2008|DOI:10.1016/j.coi.2020.04.005|DOI:10.3389/fphys.2014.00284 +CL:1001005 CL_1001005 "The glomerular capillary endothelial cell comprises an intrinsic component of the glomerulus in the kidney. Glomeruli contain a network of capillaries where the first step of blood filtration takes place, with glomerular capillary endothelial cells acting as an integral part of this process. Unlike regular endothelial cells that line the vasculature, unique fenestrations (openings) characterize these cells, allowing for enhanced permeability and filtration efficacy. + +Together with the glomerular basement membrane and podocytes, the glomerular endothelial cells form the glomerular filtration barrier, which is responsible for blood filtration and therefore critical for removal of waste products, such as urea and creatinine, and excess substances, such as glucose and ions, from the bloodstream. The glomerular capillary endothelial cells' fenestrations permit the free flow of a variety of particles, barring larger, negatively charged proteins like serum albumin, enabling the formation of an ultrafiltrate. This ultrafiltrate is the primitive form of urine, which then passes through the proximal tubule for further processing and ultimately helps maintain systemic fluid and electrolyte balance. + +Moreover, the glomerular capillary endothelial cells are also believed to play a crucial role in renal pathologies. Any compromise to their structural integrity or functional performance can lead to kidney diseases, including but not limited to, diabetic nephropathy and glomerulonephritis. For instance, in diabetes, persistent hyperglycemia can injure these cells, leading to a compromised glomerular filtration barrier and proteinuria, indicating the loss of proteins in the urine. + + + +" DOI:10.1016/j.biocel.2010.05.015|DOI:10.1111/j.1523-1755.2005.00260.x|DOI:10.2337/diacare.28.1.164|DOI:10.3389/fphys.2021.689083|DOI:10.1016/j.yexcr.2012.02.032 +CL:1001099 CL_1001099 "Kidney efferent arteriole endothelial cells constitute a vital component of the kidney's microvascular system. They are unique endothelial cells found lining the walls of efferent arterioles, which transport blood away from the glomeruli in the kidney. + +The primary responsibilities of the kidney efferent arteriole endothelial cells involve controling renal blood flow, regulating glomerular filtration rate (GFR), and managing perfusion pressure. They do this by contracting and relaxing, effectively narrowing and widening the arteriole's lumen thereby controling the volume and rate of blood flow to the peritubular capillaries and creating the pressure gradient necessary for filtration in the glomerulus. + +Furthermore, kidney efferent arteriole endothelial cells show a high degree of plasticity in response to pathophysiological stimuli and can undergo structural and functional changes based on local needs. In conditions like hypertension and diabetes, these cells can experience hypertrophy and endothelial dysfunction, contributing to the progression of renal disease. + " DOI:10.1016/j.semcdb.2014.08.002|DOI:10.1681/ASN.2019111179|DOI:10.1016/j.semnephrol.2015.01.010|DOI:10.1038/s41581-021-00411-9 +CL:1001096 CL_1001096 "Kidney afferent arteriole endothelial cells are a specialized type of cell located within the kidneys, forming the inner lining of the afferent arterioles, which are responsible for delivering blood to the glomeruli - capillary networks responsible for filtration - from where the process of urine formation begins in the nephrons. + +The endothelial cells in the kidney afferent arterioles have a key function in regulating the blood flow and filtration. They have autocrine and paracrine signaling capabilities, meaning they can signal to themselves and other nearby cells. They produce nitric oxide, prostacyclin, and endothelin, which are powerful vasodilators and vasoconstrictors that regulate renal blood flow. These cells also engage in the mitigation of kidney injury and inflammation by promoting repair and regeneration, demonstrating the multifaceted roles these cells play in maintaining renal health. +" DOI:10.1093/ndt/gfl308|DOI:10.1046/j.0001-6772.2003.01205.x +CL:1001131 CL_1001131 "The vasa recta ascending limb cells are specialized epithelial cells that are part of the vasa recta in the kidney, a crucial component of the renal medulla that functions as a counter-current exchanger to maintain the concentration gradient required for water reabsorption. These particular cells are located in the ascending limb of the vasa recta, which takes blood flow from the medulla back to the cortex. + +The primary function of vasa recta ascending limb cells is to preserve the renal medulla's hypertonicity, necessary for the kidney's urine concentration mechanism. Unlike the vasa recta descending limb cells, the venous-like epithelial cells of the ascending vasa recta are highly fenestrated and lack pericyte coverage, which facilitates water reuptake. +As the blood flows through the ascending limb, it loses solutes and gains water, which is driven by the high solute concentration in the surrounding interstitium. This process acts in concert with cellular action in the descending limb and contributions from the so-called Loop of Henle, which helps with water and sodium chloride retrieval from the urine. + +In the context of normal physiological processes, the function of the vasa recta ascending limb cells is essential in maintaining the body's overall fluid balance, electrolyte concentration, and systemic blood pressure. Any dysfunction in these cells may lead to impaired urine concentration or dilution capability of the kidney, potentially resulting in conditions like diabetes insipidus or hyponatremia. +" DOI:10.1152/ajpregu.00657.2002|DOI:10.1111/apha.12026|DOI:10.1053/j.ajkd.2005.01.008|DOI:10.1081/jdi-100101958|DOI:10.1016/B978-0-323-35515-5.00009-9 +CL:1001285 CL_1001285 "Vasa recta descending limb cells are specialized epithelial cells found in the vasa recta, a network of blood vessels in the renal medulla. These cells line the interior surface of the descending limb of the vasa recta and play a crucial role in the filtering and regulation of substances within the blood. + +In contrast to vasa recta ascending limb cells, the arterial-like epithelial cells of the descending vasa recta are non-fenestrated and covered by a pericyte layer that regulates the medullary blood flow. They help keeping the body’s fluid and electrolyte balance in check through a process known as countercurrent exchange system, in which the cells of the descending limb are permeable to water but relatively impermeable to solutes, such as sodium and urea. As the blood descends into the medulla along its descending limb, water passively diffuses out of the vasa recta, concentrating the blood in solutes. + +In addition to their central role in water and solute exchange, these cells contribute to maintaining the medullary osmotic gradient, a critical function to concentrate urine. The osmotic gradient is created by the counterflow of water and solutes between the descending and ascending limbs of the vasa recta and the adjacent Loop of Henle. The selective permeability of the descending limb cells allows them to maintain this gradient, which in turn helps to conserve water, a vital role in the overall function of the renal system. Thus, vasa recta descending limb cells have a significant function in renal physiology, particularly in osmoregulation and fluid balance. + +" DOI:10.1152/ajpregu.00657.2002|DOI:10.1111/apha.12026#apha12026-bib-0039|DOI:10.1053/j.ajkd.2005.01.008|DOI:10.1081/jdi-100101958 +CL:1001431 CL_1001431 "The kidney collecting duct principal cell is a highly specialized type of cell found in the late distal convoluted tubule and collecting duct of the kidney's nephron. Principal cells are located at the final segments of the renal tubules, where they play a pivotal role in key homeostatic processes. + +One of their fundamental functions of kidney collecting duct principal cells is the regulation of water reabsorption, which is mediated by aquaporins (water channel proteins). Antidiuretic hormones, such as vasopressin, can stimulate the redistribution of these water channels from an intracellular pools to the apical plasma membrane of the principal cell; translocation of aquaporin (specifically, AQP2) is associated with an increase of osmotic water permeability. The water reabsorption affects the concentration of the final urine; these cells are therefore directly involved in the maintenance of the body's fluid balance. + +Kidney collecting duct principal cells also participate in sodium and potassium ions regulation. They reabsorb sodium ions from the tubular fluid back into the bloodstream, a process facilitated by the action of aldosterone, a hormone released by the adrenal glands. Similarly, the principal cells secrete potassium ions into the tubular fluid in response to aldosterone, contributing to the regulation of potassium levels in the body. Impaired function of cells can lead to various renal diseases and disorders, highlighting the vital role of kidney collecting duct principal cells in the body's homeostatic processes. +" DOI:10.1016/B978-0-12-386456-7.05402-2|DOI:10.1073/pnas.1710964114|DOI:10.1007/s11906-015-0538-0|DOI:10.1016/j.biocel.2022.106261 +CL:1001597 CL_1001597 "Seminal vesicle glandular cells belong to a specialized group of epithelial cells that form the internal lining of the seminal vesicles, a pair of male reproductive organs. These cells are located within the complex tubuloalveolar glands that make up the seminal vesicles and are known for their unique pseudostratified columnar epithelium structure. + +The primary function of these cells is the secretion of a variety of substances that ultimately constitute around 70% of the fluid volume of semen. Seminal cells produce a high-fructose fluid that serves as an energy source for the spermatozoa and promotes their motility. They also secrete other essential substances like proteins, enzymes, vitamin C, prostaglandins, and various other compounds. Collectively, these substances help in the nourishment, protection, and transportation of the spermatozoa throughout the male reproductive system and during the ejaculation process. + +Secondary to the production of seminal fluid, the seminal vesicle glandular cells also play a role in the contraction of the seminal vesicles during ejaculation. The contraction of these glands, induced by sympathetic nerves, ensures the efficient propulsion of the seminal fluid mixed with spermatozoa into the ejaculatory ducts and subsequently to the urethra. Notably, any malfunction or pathological condition affecting these cells can impact male fertility, emphasizing the importance of understanding the intricate functions of seminal vesicle glandular cells in maintaining the healthy physiological function of male reproduction. +" DOI:10.1111/j.1439-0272.1992.tb02636.x|DOI:10.1007/s00265-006-0178-0|DOI:10.1007/978-3-030-32300-4_26|https://www.ncbi.nlm.nih.gov/books/NBK499854/|https://www.sciencedirect.com/topics/veterinary-science-and-veterinary-medicine/seminal-vesicle +CL:0002250 CL_0002250 "Intestinal crypt stem cells, also known as crypt base columnar cells, are a unique type of cell, characterized by the highly specific marker LGR5, found in the intestinal epithelium. Situated at the bottom of the minute pockets known as crypts of Lieberkühn, these are undifferentiated cells that have the ability to perpetually self-renew, as well as differentiate into various other cell types that constitute the epithelial lining of the intestine. + +The fundamental role of intestinal crypt stem cells is to provide a constant supply of new cells to maintain the cellular turnover of the intestinal epithelium, a tissue known for rapid self-renewal. These stem cells are nurtured and protected by specialized epithelial and mesenchymal cells, and together constitute the intestinal stem cell niche. + +An important function of intestinal crypt stem cells is to sustain the balance between cell division and programmed cell death, called apoptosis, to ensure the integrity of the intestinal lining. Given their active proliferation rate, these stem cells initiate the creation of diverse differentiated cell types, including enterocytes (the primary absorptive cells in the intestinal lumen), goblet cells (that produce mucus to protect the epithelial layer), enteroendocrine cells (involved in producing gastrointestinal hormones), and Paneth cells (involved in secreting antimicrobial peptides). This diversity in output regulates the physiological activities of the gut ranging from nutrient absorption, hormone secretion, bacterial balance, to immunity. + +Research studies suggest that dysregulation in intestinal crypt stem cell proliferation and differentiation is associated with several intestinal disorders including intestinal cancer, and various enteropathies. +" DOI:10.1111/j.1365-2184.2009.00642.x|DOI:10.1038/s41575-018-0081-y|DOI:10.1016/j.cell.2013.07.004|DOI:10.1101/gad.1674008|DOI:10.1038/s41580-020-0278-0 +CL:0002275 CL_0002275 "Pancreatic polypeptide (PP) cells (also called F or gamma cells) are unique endocrine cells located within the Islets of Langerhans in the pancreas. PP cells are one of the rarer pancreatic cell types and are more prevalent in the head and neck of the pancreas. They are critical in normal pancreatic physiological functions and are involved in the development of pancreatic endocrine disorders. + +The primary function of PP cells is the production and secretion of the pancreatic polypeptide hormone (PP). This hormone plays a crucial role in several gastrointestinal functions and metabolic responses. The release of the PP hormone is stimulated after eating, especially in protein-rich meals, leading to it being present in large amounts during digestion. The fundamental role of PP is to self-regulate pancreatic secretion activities ensuring its exocrine and endocrine functions are under control. + +The pancreatic polypeptide hormone from PP cells also aids in adapting to low physical activity and fasting by reducing the production of insulin and glucagon and inhibiting the hepatic glucose production. Additionally, this hormone influences gut motility by slowing down the gastric emptying and reducing small intestinal transit, thereby controlling the pace at which nutritional substances are absorbed. Because of these functions, any malfunction or irregularity in PP cells can result in various disorders such as diabetes and pancreatic diseases. +" DOI:10.1038/s42255-019-0148-2|DOI:10.1016/B978-012369442-3/50154-9|DOI:10.3389/fendo.2023.1192311|DOI:10.1016/j.mce.2015.06.028|DOI:10.1016/B978-0-12-819402-7.00001-2 +CL:0002303 CL_0002303 "Pigmented ciliary epithelial cells, which are a type of pigment cell, have a crucial function within the eye's ciliary body. The ciliary body, located behind the iris, is one of the eye’s most vital structures and consists of two types of epithelial cells: the pigmented and the non-pigmented ciliary epithelial cells. The pigmented ciliary epithelial cells form the outer layer of the ciliary body and exhibit a black or brown pigmentation due to the melanin they contain. + +One key function of pigmented ciliary epithelial cells is to aid in the formation of aqueous humor, an intraocular fluid that nourishes the cornea and lens, and maintains intraocular pressure which is essential for the eye’s shape and light refraction. These cells facilitate this function in conjunction with the non-pigmented ciliary epithelial cells. Together, the pigmented and non-pigmented ciliary epithelial cells form a bilayer epithelium that allows the secretion of aqueous humor through a bi-directional fluid transport mechanism. + +Pigmented ciliary epithelial cells also contribute to the blood-aqueous barrier, a physiological frontier that controls the entry and exit of various substances from the blood to the aqueous humor and vice versa. The pigmentation in these cells, intensified by melanin, helps to absorb scattered light coming into the eye, reducing any potential damage and glare. +" DOI:10.1016/S1569-2590(05)10005-6|DOI:10.1111/j.1444-0938.2002.tb02384.x +CL:4023181 CL_4023181 "Hypendymal cells are secretory cells located between the ependymal layer and the posterior commissure, forming the hypendmal layer of the subcommissural organ (SCO), a highly conserved gland that is part of the circumventricular system within the brain. + +Hypendymal cells are bipolar cells with a thin apical pole and basal process. Most of the ultrastructural characteristics of these cells are similar to those described for the ependymal cells (which are arranged into another layer – the ependyma). However, ependymal cells release their secretion into the ventricular cerebrospinal fluid whereas hypendymal cells project processes to the local blood vessels and to the subarachnoidal space. + +" DOI:10.1111/joa.13709|DOI:10.1002/(SICI)1097-0029(19980415)41:2<98::AID-JEMT2>3.0.CO;2-M|DOI:10.3389/fncel.2015.00480 +CL:0017000 CL_0017000 "The pulmonary ionocyte is a relatively newly identified, specific epithelial cell type found primarily in the pulmonary or respiratory system. Discovered through novel mapping techniques in 2018, these cells are surprisingly rare, making up less than 2% of the cells in the lung's airway, yet they play an essential role in the airway surface liquid and mucus regulation, a crucial factor in lung health. + +The main responsibility of the pulmonary ionocyte pertains to the regulation and mobilization of chloride ions. They express a high level of CFTR (Cystic Fibrosis Transmembrane Conductance Regulator) gene, which encodes a protein channel across the membrane of cells that produce mucus, sweat, saliva, tears, and digestive enzymes. The activity of CFTR regulates the movement of chloride ions and fluids in and out of cells, which helps maintain a balance of fluid in the organs they are expressed in. If CFTR is dysfunctional, it can cause conditions such as cystic fibrosis, characterized by thick, sticky mucus that can clog the lungs and obstruct the pancreas, leading to respiratory and digestive issues. + +The discovery of this cell type offers new doors to the treatment and further understanding of diseases like cystic fibrosis. Increased understanding of pulmonary ionocytes could contribute to the development of novel therapeutic approaches to manipulate the function of CFTR in the lungs and other organs affected by dysfunctional CFTR. +" DOI:10.1038/s41586-018-0393-7|DOI:10.1146/annurev-pathol-042420-094031|DOI:10.1172/JCI171268 +CL:1000143 CL_1000143 "Lung goblet cells are critical components of the respiratory tract, specifically found in the bronchial segments. They are secretory epithelial cells known for their signature ""goblet"" or cup-like shape. Their primary function is to produce and secrete mucus that aids in trapping airborne particles and pathogens, preventing them from reaching the delicate environment of the lung. As part of the lung's epithelial lining, they act as frontline defenders, maintaining lung health and function. + +The lung goblet cells are densely packed with granules containing mucin glycoproteins, the primary component of mucus. As mucus is produced and secreted, it moves towards the lumen of the lungs where the cilia, hair-like structures of the neighboring ciliated epithelial cells, help to navigate it upwards and out of the respiratory tract. This coordinated action ensures the expulsion of unwanted particles and pathogens, effectively cleaning the respiratory tract. + +Dysfunction or abnormal proliferation of lung goblet cells can result in pathological conditions such as chronic obstructive pulmonary disorder (COPD) and asthma, where excessive mucus production leads to airway obstruction. Furthermore, lung goblet cells respond to a variety of stimuli, including toxins, allergens, irritants, and infections, adjusting their mucus production accordingly. +" https://www.ncbi.nlm.nih.gov/books/NBK553208/|DOI:10.1038/s41385-020-00370-7|DOI:10.1038/s41385-018-0039-y|DOI:10.1513/AnnalsATS.201802-128AW |DOI:10.1159/000512268 +CL:1000223 CL_1000223 "Lung neuroendocrine cells, also commonly known as pulmonary neuroendocrine cells (PNECs), are predominantly located in the respiratory epithelium of the bronchial and bronchiolar airways in the lungs. These cells, characterised by their small size and granular appearance, have a distinctive morphology that sets them apart from other lung cells. They are considered part of the diffuse neuroendocrine system due to their scattered distribution through the epithelium and have been classified into solitary cells and clustered forms known as neuroepithelial bodies. + +The primary function of PNECs is linked to regulation and maintenance of the lung environment. They are sensory in nature and can secrete various bioactive substances such as serotonin, calcitonin, calcitonin gene-related peptides, and bombesin-like peptides which modulate airway smooth muscle tone and influence gut motility. For example, they act as oxygen sensors in response to hypoxia and are responsible for releasing neuropeptides that can induce responses. Moreover, PNECs provide an afferent function as they are equipped with long microvilli that project into the lumen of the bronchus and react to changes in the chemical composition of the luminal content. +" DOI:10.1016/j.devcel.2020.09.024|DOI:10.1016/bs.ctdb.2018.12.002|DOI:10.1242/dmm.046920 +CL:0000166 CL_0000166 "Chromaffin cells, also known as pheochromocytes, are neuroendocrine cells that are typically located in the adrenal medulla, the innermost part of the adrenal gland, which is situated on top of each kidney. Chromaffin cells are also found in small clusters, known as paraganglia, in various locations throughout the body, including the sympathetic nervous system. They derive their name from their ability to stain a brownish-black color upon exposure to chromic salts, a feature made possible due to their high content of granules rich in catecholamines and catecholamine-related neurotransmitters. + +The primary function of chromaffin cells is the synthesis and release of catecholamines, specifically epinephrine (adrenaline) and norepinephrine (noradrenaline). These neurotransmitters are vital stress hormones that, when released by the adrenal chromaffing cells into the bloodstream, prepare the body for the 'fight or flight' response. This response can enhance the body's performance in a dangerous situation by increasing heart rate, elevating blood sugar, and increasing blood flow to the muscles. The chromaffin cells in paraganglia are responsible for the local release of catecholamines and play a role in regulating blood pressure and other autonomic functions. + +In addition to their role in stress response, chromaffin cells also contribute to the body's immune response. They secrete several peptides including antimicrobial peptides, and the discovery of LPS and cytokine receptors on chromaffin cells suggests that the adrenal medulla may participate in some aspects of the immune response. + +" DOI:10.1002/cphy.c190003|DOI:10.3389/fimmu.2022.977175/full|DOI:10.1016/j.biocel.2016.02.003|DOI:10.3389/fimmu.2022.977175|DOI:10.3389/fendo.2018.00711 +CL:0000091 CL_0000091 "Kupffer cells are tissue-resident macrophages located in the liver. They are an integral part of the mononuclear phagocyte system and are responsible for the phagocytosis of dead or dying cells, microbes, and other foreign substances. Kupffer cells account for approximately 80-90% of tissue-resident macrophages in the body. They are found within the lumen of liver sinusoids and interface with microbial populations and products. + +The primary role of Kupffer cells is to maintain homeostasis in the liver. They continuously filter and cleanse the blood that flows through the liver, removing pathogens, endotoxins, particulate matter, aged and dysfunctional red blood cells, and miscellaneous waste products. These cells also play an important role in maintaining iron homeostasis. During the process of phagocytosis, Kupffer cells recycle iron from degraded red blood cells, which is then utilized in the formation of new erythrocytes. + +Kupffer cells also play key roles in various immune responses and inflammatory processes. They secrete various types of cytokines and chemokines, which contribute to the activation and mobilization of other immune cells. They can also produce reactive oxygen species and nitric oxide, which have microbicidal actions. Although their activity is essential for host defense, excessive or prolonged activation of Kupffer cells may contribute to hepatic injury, inflammation, and fibrosis. +" DOI:10.1038/nri.2017.11|DOI:10.1016/j.immuni.2022.08.002|DOI:10.1002/cphy.c120026|DOI:10.1111/j.1478-3231.2006.01342.x|DOI:10.1007/978-1-4939-1311-4_10 +CL:0000113 CL_0000113 "Mononuclear phagocytes are immune cells that form a critical part of the body's innate immune system, the body's first line of defense against infections. Mononuclear phagocytes are characterized by the presence of a single, large nucleus. The ‘Mononuclear Phagocyte System’ nomenclature was introduced to distinguish mononuclear monocytes and macrophages from other cells with multiple nuclei. However, the cells within the mononuclear phagocyte system represent a highly heterogeneous group, all of which are able to perform highly efficient phagocytosis - engulfing and digesting microbes and cellular debris to fight infections and to maintain normal tissue homeostasis. + +In addition to phagocytosis, mononuclear phagocytes also secrete chemical compounds to recruit other immune cells to a site of infection. These cells produce different types of signaling molecules, including cytokines, chemokines, and reactive oxygen species, triggering a cascade of responses to ensure rapid and efficient containment and neutralization of invading pathogens. These cells are also involved in antigen presentation, a process essential for stimulating an adaptive immune response. They can process and present antigens to T cells, thereby linking the innate and adaptive immune responses. + +Mononuclear phagocytes play key roles in tissue repair and remodeling. After infection or injury, these cells help in the clearance of dead cells and debris, a crucial step in the initiation of tissue remodeling and the resolution of inflammation. Overall, mononuclear phagocytes are versatile cells that have tailored their functions to meet the unique challenges of different tissues within the body. They are pivotal in homeostasis, immunity, and inflammation, making them important aspects in a range of human diseases including infection, autoimmunity, and cancer. +" DOI:10.1038/nri3087|DOI:10.1016/j.coi.2005.11.008|DOI:10.3389/fimmu.2019.01893|DOI:10.3389/fimmu.2019.01893 +CL:0000125 CL_0000125 "Glial cells, also known as neuroglia or simply glia, are non-neuronal cells in the central and peripheral nervous systems that provide support and protection for neurons. They constitute approximately half of the total cells in the human brain and more than half in other parts of the nervous system. Glial cells perform several key functions including, but not limited to, maintaining homeostasis, forming the myelin sheath around the neuron axons, and providing support and nutrition to neurons. + +These different functions are performed by various glial cell types, including astrocytes, oligodendrocytes, microglia and other specialized types. Astrocytes, for example, are the most abundant glial cells and provide metabolic and nutrient support to neurons, help regulate the extracellular ion and neurotransmitter levels, and play a role in the formation and maintenance of the blood-brain barrier, contributing to the overall homeostasis and functioning of the nervous system. Additionally, astrocytes are involved in synaptic communication and participate in processes such as synaptogenesis and synaptic pruning. + +Oligodendrocytes in the central nervous system function to insulate neurons by producing a fatty substance known as myelin. The myelin sheath enhances the speed and efficiency of nerve impulse conduction along the axons. + +Microglia, the immune cells of the central nervous system, protect neurons from pathogens and clear away dead neurons through phagocytosis, a process also known as cellular eating. They also contribute to the regulation of inflammation in response to signals of tissue damage or infection in the central nervous system by releasing cytokines and other signaling molecules that modulate the immune response. + +Despite their overarching function in the support and protection of neurons, glial cells have also been shown to play significant roles in the pathophysiology of many psychiatric and neurodegenerative diseases, such as Alzheimer’s, Parkinson’s Disease and multiple sclerosis. +" DOI:10.1126/science.aat0473|DOI:10.1101/cshperspect.a020602|DOI:10.1002/glia.24343|DOI:10.3389/fncel.2017.00024|DOI:10.1038/nn1988 +CL:0000121 CL_0000121 "Purkinje cells, named after the Czech anatomist Jan Evangelista Purkyně who discovered them, are unique inhibitory neurons in the cerebellar cortex. They are a critical part of the vertebrate nervous system as they provide the only signal output from the cortex to the cerebellar nuclei. They are one of the few types of neurons that are large enough to be seen with the naked eye. The most distinct hallmark of Purkinje cells is their elaborate dendritic arbor, which forms a broad and intricately branching structure resembling a tree. These numerous branches each receive excitatory synaptic inputs from more than 100,000 parallel fibers; in addition, a single climbing fiber makes hundreds of synapses to the soma and proximal dendrites. A single long axon forms an inhibitory projection to the cerebellar nuclei. + +Purkinje cells play key roles in the coordination of fine, voluntary motor movements and balance. As the sole output of all motor coordination in the cerebellar cortex, they serve as a central relay in the cerebro-cerebellar loop. Each Purkinje cell receives two types of synaptic input: one from parallel fibers (which are axons of granule cells), and the other from climbing fibers (originating from the inferior olivary nucleus). The Purkinje cells process and integrate these diverse kinds of input signals to generate output that controls timing and coordination of movements. + +Purkinje neurons show considerable synaptic plasticity. Throughout life, these cells continue to undergo long-term potentiation and depression at parallel fiber synapses, which cause long-lasting increase or decrease, respectively, of synaptic transmission and have been proposed as mechanisms for motor learning. + +Purkinje cells are also known to be implicated in a variety of diseases. Their progressive loss is a prime feature in certain types of ataxia, a collective term used to describe conditions characterized by loss of muscular control and coordination. Furthermore, a significant reduction in the density of Purkinje cells has been reported in conditions such as autism and Huntington’s disease. +" DOI:10.1007/s12311-018-0985-7|https://www.ncbi.nlm.nih.gov/books/NBK545154/|DOI:10.1038/nrn3886|https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/purkinje-cell|DOI:10.7554/eLife.63668 +CL:0000164 CL_0000164 "Enteroendocrine cells are a specialized subset of cells located within the epithelial lining of both the small and large intestines, as well as the stomach and pancreas. Constituting less than 1% of the total population of intestinal cells, they are differentiated from a common intestinal cell progenitor, thus sharing lineage with absorptive and goblet cells of the intestines. + +The distinct characteristic feature of an enteroendocrine cell is its inherent capacity to synthesize and secrete a plethora of gut hormones such as serotonin, somatostatin, neurotensin, cholecystokinin, secretin, gastric inhibitory peptide, motilin, and glucagon-like peptide-1. Integrated within this complex network of signaling agents, these substances control various aspects of the digestive system. Each enteroendocrine cell has its unique combination of hormones to release, determined by its position along the intestinal tract. Intriguingly, these hormones not only modulate local gut function, including motility, absorption and secretion, but also potentiate distant actions on other systems such as endocrine, nervous and immune and play a role in the feeling of satiety. + +The release of these hormones from enteroendocrine cells is a highly regulated and dynamic process. The cells are equipped with sensory receptors localized on its luminal side that respond to various stimuli, including changes in nutrient composition, chemical or mechanical changes in the gut lumen, or even signals arising from commensal microbiota. This sensory input stimulates a signaling cascade within the cell, culminating in the release of specific hormones into the interstitial fluid. These hormones then make their way into the bloodstream, acting on their respective target receptors to mediate their duties. The multifunctional characteristics of enteroendocrine cells make them crucial for maintaining gut homeostasis and the overall physiological well being of the body. +" DOI:10.1038/s41574-019-0168-8|DOI:10.1210/endrev/bnaa018|DOI:10.1111/j.1463-1326.2011.01438.x|DOI:10.7554/elife.78512|DOI:10.1196/annals.1294.001 +CL:0000160 CL_0000160 "Goblet cells are specialized, simple columnar, secretory epithelial cells that are mostly found in the respiratory and intestinal tracts. The term ""goblet"" refers to their shape, which resembles a flask or goblet, specially at their apical end which is swollen due to the accumulation of secretory granules. + +The primary function of goblet cells is to to protect and lubricate the underlying tissues by secreting large quantities of mucin, a complex glycoprotein, which forms mucus when hydrated. In the respiratory tract, the mucus secreted by these cells traps dust, bacteria, viruses, and other potentially harmful particles in the inhaled air, preventing them from reaching the delicate tissues of the lungs. In the intestines, the goblet cells secrete mucus that acts as a protective barrier shielding the intestinal epithelium from dietary antigens, pathogens and prevents the intestinal epithelium from being eroded by the actions of the digestive enzymes and the abrasive action of passing food material. + +Goblet cells are capable of rapidly altering their secretory output in response to stimuli. For example, irritants like smoke or dust can trigger an increased rate of mucus production, as the body attempts to flush out the harmful particles. Conversely, in conditions such as chronic bronchitis and cystic fibrosis, overactive goblet cells can create a thick accumulation of mucus that obstructs the airways and fosters bacterial growth. Lastly, goblet cells are not static, rather, they undergo a dynamic process known as goblet cell metaplasia-differentiation, wherein non-goblet cells in response to chronic injury or inflammation, can differentiate into goblet cells leading to an accumulation of these cells in the tissue, known as goblet cell hyperplasia." DOI:10.1038/s41575-022-00675-x|DOI:10.1016/S1357-2725(02)00083-3|DOI:10.1165/ajrcmb.25.5.f218|DOI:10.1242/bio.20121701|https://www.ncbi.nlm.nih.gov/books/NBK553208/ +CL:0000182 CL_0000182 "Hepatocytes are the major cell type constituting 70-80% of the liver's cytoplasmic mass, playing crucial roles in maintaining the body's metabolic homeostasis. Dimensions of mature hepatocytes typically range from 20 to 30 μm in humans, but size may vary depending on their location within the liver lobule. Hepatocytes are characterized by high biosynthetic, enzymatic, and endocytic activity. They contain abundant mitochondria, smooth and rough endoplasmic reticulum, peroxisomes, lysosomes, and a large nucleus that is often binucleate. + +The liver consists of three zones - the periportal Zone 1, midzone 2, and pericentral Zone 3 - which have differential nutrient and oxygen status, and damage susceptibility; hepatocytes in the different zones show signifcant functional heterogeneity ('hepatocyte functional zonation'). Hepatocytes are involved in a multitude of critical functions including the metabolism of lipids, carbohydrates, and proteins, the synthesis of serum proteins (e.g., albumin, transferrin, and lipoproteins), the detoxification and excretion of endogenous and exogenous substances, the storage of vitamins and minerals, and the production and secretion of bile. + +Heterocytes demonstrate a remarkable regenerative capacity, which enables the liver to recover from injury and loss of tissue mass. Notably, hepatocytes perform biotransformation with both phase I and phase II enzymes, which modify drugs, xenobiotics, and various substances for elimination from the body. Phase I enzymes, such as cytochrome P450, catalyze both oxidative and reductive reactions of many xenobiotics; many of the products of phase I enzymes are substrates for the phase II enzymes, which catalyze conjugation reactions. + +Alterations in hepatocyte function have significant implications for overall human health and disease. Certain conditions, such as hepatitis, cirrhosis, and liver cancer, can profoundly affect hepatocyte structure and function, thereby disrupting the liver's ability to perform its vital roles within the body. As the primary site for drug metabolism, changes in hepatocyte function can also impact the effectiveness and toxicity of pharmaceuticals. The regenerative ability of hepatocytes makes them valuable cells for liver regenerative medicine and bioartificial liver support systems, and their study has provided significant insights into liver biology and disease." DOI:10.1083/jcb.201903090|DOI:10.1111/j.1439-0396.2007.00752.x|DOI:10.1016/j.biocel.2011.11.011|DOI:10.1016/j.biocel.2011.11.011|DOI:10.1055/s-2007-1007096 +CL:0000178 CL_0000178 "Leydig cells are a testosterone-secreting cell in the interstitial area in the testes of males. They are named after Franz Leydig, a German anatomist who discovered these cells in 1850. Uniquely situated within the soft connective tissue surrounding the seminiferous tubules, Leydig cells form an integral part of the male reproductive system. They are usually polygonal cells characterized by well developed smooth endoplasmic reticulum, high lipid content and a large round nucleus. They are found across mammalian species, including humans. + +The primary function of Leydig cells is the production of androgens, the male sex hormones, the most notable of which is testosterone. Leydig cells synthesize testosterone from cholesterol through a series of enzymatic reactions. The production and release of testosterone are mainly regulated by the luteinizing hormone (LH) released by the anterior pituitary gland. In response to LH, Leydig cells convert cholesterol into testosterone, which then plays a crucial role in the development and maintenance of primary and secondary male sexual characteristics. These include the formation and maturation of male reproductive organs, onset of spermatogenesis, and the presentation of male secondary sexual traits such as the deepening of the voice, growth of facial hair, development of muscles, and a broadening of shoulders. + +Apart from testosterone production, Leydig cells also secrete insulin-like factor 3 (INSL3) that is essential for testicular descent during embryonic development in males. Dysregulation or loss of Leydig cells can lead to numerous conditions like testosterone deficiency, infertility, and certain forms of testicular cancer. Although not typical, Leydig cells can regenerate if they are damaged, ensuring the continuous production of testosterone and maintaining male reproductive health. They provide an excellent model to study cell differentiation and hormone regulation, thereby enhancing our understanding of reproductive biology and associated disorders. + + +" DOI:10.1093/biolre/ioy059|DOI:10.3389/fendo.2014.00006|DOI:10.1210/clinem/dgaa603|https://www.ncbi.nlm.nih.gov/books/NBK556007/#:~:text=Leydig%20cells%20are%20the%20primary,secondary%20sexual%20characteristics%20and%20behaviors.|DOI:10.1016/j.coemr.2019.03.001 +CL:0000501 CL_0000501 "Granulosa cells are a type of somatic cell most commonly known for their crucial role within the ovarian follicles of female mammalian species. Named for their grainy appearance, they are situated in the follicular epithelium, lining the inner part of the follicle and directly surrounding the oocyte. These cells stand as an integral part of the ovarian structure and function. + +One of the primary roles of granulosa cells is to aid in the production and secretion of sex hormones, particularly estrogen. They achieve this by working in tandem with theca cells, which stay attached to the external layer of the follicle. Theca cells produce androstenedione (a type of androgen) which granulosa cells then convert into estradiol, a form of estrogen, with the help of the enzyme aromatase. Moreover, granulosa cells participate in luteinization, transforming into luteal granulosa cells as a response to the luteinizing hormone during ovulation. This allows the formation of the corpus luteum, responsible for the secretion of progesterone necessary to maintain pregnancy. + +Granulosa cells also play a significant role in follicular development and oocyte maturation, involving close communication with the contained oocyte. They support the oocyte through the provision of nutrients and growth factors, control its meiotic cycle and ensure it is appropriately oriented and instructed for impending ovulation. Furthermore, granulosa cells contribute to the formation of the zona pellucida and the follicular fluid, providing an optimal environment for the oocyte's growth and maturation. These cells, thus, perform multiple vital roles, underscoring their importance in fertility and reproductive health. +" DOI:10.1016/j.ejogrb.2004.01.010|DOI:10.1093/humrep/del408|DOI:10.1210/jcem-28-3-355|DOI:10.3389/fendo.2019.00832/full|DOI:10.1093/humupd/6.3.279 +CL:0000502 CL_0000502 "Type D enteroendocrine cells, also known as D or delta cells, are specialized hormone-releasing cells found in the pancreas and also scattered throughout the lining of the gastrointestinal tract in mammals, notably within the stomach and the upper part of the small intestine known as the duodenum. The primary role of D cells is to produce and secrete somatostatin, a potent paracrine inhibitor. + +In the gastrointestinal tract, somatostatin slows down digestion. It reduces gastric acid secretion and slows down the rate of gastric emptying, thereby prolonging and controling the digestive p. Functionally, these effects are aimed at sustaining nutrient absorption to optimize energy extraction from consumed food. + +In the pancreas, D cells maintain a vital role in endocrine regulation. D cells in the pancreatic islands secrete somatostatin to inhibit the release of both insulin and glucagon from type A cells and B cells, glucoregulatory hormones that control blood sugar levels. Hence, D cells contribute considerably to the homeostasis of the body's metabolic processes. It is also noteworthy that dysfunctional D cells or irregular somatostatin signaling has been associated with certain pathologies such as neuroendocrine tumors and gastric ulcers. +" DOI:10.1038/s41574-018-0020-6|DOI:10.1016/j.pharmthera.2015.05.007|DOI:10.1093/annonc/mdh216|https://www.sciencedirect.com/topics/neuroscience/somatostatin-cell +CL:0000510 CL_0000510 "Paneth cells are specialized epithelial cells that are primarily located at the bottom of the crypts of Lieberkühn in the small intestine, where they play a pivotal role in maintaining gut homeostasis. They have also been found in smaller numbers in the colonic crypts and other parts of the gastrointestinal tract. Paneth cells are characterized by large acidophilic granules, which take up most of the cytoplasmic volume, causing the nucleus to be pushed toward the base of the cell. + +Paneth cells function as a part of the innate immune system. The large granules inside the cells are filled with antimicrobial peptides, such as defensins and lysozymes. Upon bacterial intrusion or cellular signaling indicating a potential infection, Paneth cells release the granules containing the antimicrobial substances into the crypt lumen, effectively serving as the first line of defense against bacterial invasion within the gastrointestinal tract. In essence, Paneth cells serve as guardians, protecting the intestinal stem cells from harmful pathogens that may disturb the gut ecosystem. + +In addition to their primary role in immunity, Paneth cells are also crucial for supporting the stem cell niche in the intestinal crypts. They are located adjacent to Lgr5+ stem cells and secrete various growth factors such as EGF, TGF-alpha, Wnt3, and Notch ligand Dll4. These factors regulate the self-renewal and differentiation of these stem cells, which continuously replenish the intestinal epithelium. Consequently, any abnormality or dysfunction in Paneth cells could lead to a disturbance in gut homeostasis, possibly resulting in various illnesses such as inflammatory bowel disease. +" DOI:10.1146/annurev-physiol-030212-183744|DOI:10.1038/nrmicro2546|DOI:10.1038/nature09637|DOI:10.1007/s00018-002-8412-z|DOI:10.3389/fimmu.2020.00587 +CL:0000577 CL_0000577 "Type EC enteroendocrine cells, also known as enterochromaffin cells, are a vital hormone-secreting cell type found in the gastrointestinal tract. These cells are named after their location in the intestines (“entero”) and because they are stainable by chromium salts (“chromaffin”). + +The primary function of type EC enteroendocrine cells is to act as chemosensors and lies in their capacity to produce and secrete serotonin, also known as 5-hydroxytryptamine (5-HT). Serotonin is a neurotransmitter that plays a significant role in modulating motility, secretion, vasodilation, perception of pain, and appetite in the gastrointestinal system. However, its function is not limited to the gastrointestinal tract; once secreted, serotonin is distributed via the bloodstream and contributes to regulating mood, appetite, and sleep in the brain. + +Via specific chemosensory receptors type EC enteroendocrine cells are able to respond to various environmental, metabolic, and homeostatic stimuli and transduce information from the gut to the nervous system: Food intake, particularly the ingestion of fats and carbohydrates, prompts these cells to produce and release serotonin; the mechanical stimulus of food in the lumen can also trigger release. The distribution, function, and responsiveness of type EC cells reveal them as a crucial link between the intestinal environment, the nervous system, and the regulation of numerous bodily functions. +" DOI:10.1016/j.cell.2017.05.034|DOI:10.1016/0166-4328(96)00075-7|DOI:10.1038/s41574-019-0168-8|DOI:10.1073/pnas.1804938115 +CL:0000583 CL_0000583 "Alveolar macrophages are unique tissue-resident macrophages found in the lungs, specifically in the air sacs or alveoli where gas exchange occurs. They are characterized by specific surface markers including: F4/80-positive, CD11b-/low, CD11c-positive, CD68-positive, sialoadhesin-positive, dectin-1-positive, MR-positive, CX3CR1-negative. These specialized immune cells form a crucial part of the body's defense mechanism, playing important roles in pulmonary health and homeostasis. They are the first line of defense in the pulmonary immune response, acting as scavengers that patrol the alveoli and engulf foreign particles like bacteria, dust, and other debris that enter the lungs through inhalation. + +The primary function of these alveolar macrophages is phagocytosis, whereby they consume and digest foreign substances, dead cells, and other particulates. In the lung, alveolar macrophages are also responsible for clearing surfactant. Additionally, alveolar macrophages also play an integral role in initiating the immune response, as they secrete several pro-inflammatory cytokines and chemokines that recruit other immune cells to the site of infection or inflammation. + +Beyond their role in host defense, alveolar macrophages contribute to tissue remodeling and wound repair in the lungs, aiding in maintaining lung integrity. They also regulate local inflammation and control the immune response to prevent excessive inflammation that may be harmful. However, an imbalance in the function of alveolar macrophages can contribute to various lung diseases. Abnormal alveolar macrophage activation has been implicated in chronic inflammatory diseases such as emphysema, asthma, and fibrosis. +" DOI:10.1016/j.cellimm.2018.01.005|DOI:10.1038/nri3600|DOI:10.14348/molcells.2021.0058|DOI:10.1007/s00424-017-1965-3 +CL:0000622 CL_0000622 "Acinar cells are specialized exocrine gland cells that secrete specific enzymes and fluids to aid in digestion. Found primarily in the pancreas and salivary glands, the term acinar is derived from the Latin word 'acinus' which means 'grape'; this is because acinar cells are arranged in a grape-like cluster around small ducts, formulating an acinus structure. + +In the salivary glands, acinar cells secrete digestive enzymes as well as other substances such as mucus and water. These secretions service the initial stages of the digestive process, preparing the consumed food for onward digestion in the stomach and intestines by lubricating and partially breaking it down. + +In the pancreas, acinar cells are responsible for synthesizing and secreting a significant amount of digestive enzymes, such as trypsin, chymotrypsin, and amylase. These enzymes are stored in zymogen granules inside the acinar cells until they are dispatched into the small intestine. Once within the small intestine, they break down proteins, carbohydrates, and fats into substances that can be absorbed. This is vital to the effective and efficient digestion and absorption of nutrients from the food we consume. + +Acinar cells have high protein synthesis rates and are susceptible to accumulation of misfolded proteins; the subsequential induction of ER stress is thought to be involved in the development of pancreatitis, a serious inflammatory disease of the exocrine pancreas. +" DOI:10.1097/MOG.0b013e32832ebfac|DOI:10.1038/nrgastro.2013.36|DOI:10.1007/BF00710764|DOI:10.1111/prd.12116|DOI:10.1152/physrev.00011.2011 +CL:0000653 CL_0000653 "Podocytes are highly specialized, terminally differentiated glomerular visceral epithelial cells that wrap around the capillaries in the kidneys. They play an essential role in kidney function, particularly in the filtration selectivity of the glomerulus. Each podocyte is characterized by a unique architecture with a large cell body, ‘major processes’ extending outwardly from the cell body and ‘foot processes’, also known as pedicels, which surround. the glomerular capillary loops + +Podocytes represent the last barrier of the glomerular filtration membrane in the kidney. This barrier prevents the leakage of plasma proteins from the blood into the urine, hence maintaining protein homeostasis in the body. The foot processes of the podocytes interdigitate with those from neighboring cells. The cell-cell junctions between the foot processes, the slit-diaphragms, are thought to create a molecular sensor of renal filtration that prevents the passage of macromolecules while allowing water and small solutes to pass. +Podocytes also contribute to the glomerular basement membrane by secreting collagen and maintain glomerular endothelial cell fenestration by secreting VEGFA. They have been shown to play a role in inducing cytoskeletal regulation, cell adhesion, and inflammatory response, consistent with their essential function in the kidney. + +The importance of podocytes is further emphasized by the effects of their damage or loss. Abnormalities in podocytes often result in severe kidney diseases (podocytopathies), including focal segmental glomerulosclerosis (FSGS) and minimal change disease (MCD). Injury to the podocytes can result in ""effacement"" or flattening of foot processes, leading to increased permeability of the filtration barrier and proteinuria (an excess of serum protein in urine) which is a common symptom of kidney diseases. +" DOI:10.1159/000481633|DOI:10.1038/s41572-020-0196-7|DOI:10.3389/fcell.2021.771931|DOI:10.1038/s41467-022-33748-1|DOI:10.1146/annurev-physiol-020911-153238 +CL:0000666 CL_0000666 "Fenestrated cells are specialized epithelial cells that are characterized by a distinctive structural feature, fenestrations or tiny pores, which allow an exchange of substances such as fluids, nutrients, and waste between blood vessels and the surrounding tissue environments. These cells are present in various types of epithelial tissues in the human body, including the intestinal tract, endocrine glands, and certain parts of the renal system. + +There are multiple types of endothelial cell fenestrations. The most common type is found in systemic capillaries of the endocrine tissue (e.g., pancreatic islets), gastrointestinal mucosa, and renal peritubular capillaries. Here, the fenestrated cells have fenestrations in their peripheral cytoplasm with a unique thin and permeable diaphragm that provides a high degree of selectivity, blocking the passage of larger molecules while allowing the free movement of smaller ones. In contrast, other types of fenestrations, such as the discontinuous epithelium of the liver sinusoidal endothelial cells, do not have diaphragms. + +Characteristically, fenestrated cells play a vital role in the filtering process of body systems. They are a key part of the glomeruli in the kidneys where blood is filtered under high pressure. The fenestrations present in the endothelial cells lining the capillaries of the glomerulus allow the free passage of water and small solute molecules towards the Bowman's capsule, leaving behind larger proteins and cells in the blood, thereby aiding in the filtration and waste removal process. + +In the endocrine system, fenestrated cells in glandular capillaries allow the prompt release of hormones into the bloodstream. These cells have tightly clustered fenestrations which increase the surface area available for passive diffusion, improving the efficiency of hormone secretion. In villi of the small intestine, these cells increase absorption efficiency, permitting the exchange of water, electrolytes, and nutrients. + +Overall, fenestrated cells contribute immensely to important physiological processes of filtration, absorption, and secretion, primarily connecting our body's circulation system with the surrounding tissues and organs. +" DOI:10.1016/j.devcel.2012.11.003|DOI:10.1152/ajprenal.90601.2008|DOI:10.1016/0306-4522(86)90162-4|DOI:10.1002/ar.1092200109|DOI:10.1038/s41467-022-31571-2 +CL:0000682 CL_0000682 "M cells, or microfold cells, of the gut are specialized epithelial cells found in the lining of the gut, specifically in the follicle-associated epithelium of mucosa-associated lymphoid tissue, where they function as sentries against toxins and pathogens. M cells are characterized by apical microfolds (hence their alternate name) which express unique adhesion molecules that enable them to sample the luminal macromolecules. + +Other morphological features that distinguish M cells from other intestinal mucosal cells include sparse microvilli and a reduced thickness of the glycocalyx, which permits adhesion while not hindering the transport of molecules. They also have unique intraepithelial invaginations on the basolateral side which are filled with macrophages and other immune cells that can process the engulfed macromolecules quickly. + +These morphological characteristics enable M cells to serve a dual role in immune responses. They initiate the immune response by transporting antigens (such as toxic or pathogenic substances) across the epithelial layer to lymphocytes and antigen-presenting cells in the underlying lymphoid tissue. This specialized transport process is called 'transcytosis.' They also have specialized molecules like glycoprotein-2 for bacterial uptake. Simultaneously, M cells help maintain immune tolerance to food antigens and commensal bacteria, preventing unnecessary reactions to non-pathogenic substances and hypersensitivity conditions. While these functions are crucial for well-being, M cell dysfunction can lead to serious conditions like Crohn's disease and other inflammatory bowel diseases. + +" DOI:10.1093/jb/mvv121|DOI:10.1136/gut.47.5.735|DOI:10.1038/nature08529|https://www.ncbi.nlm.nih.gov/books/NBK534232/|https://www.sciencedirect.com/topics/medicine-and-dentistry/microfold-cell +CL:0000696 CL_0000696 "PP cells, also known as pancreatic polypeptide cells (and previously called F cells or gamma cells), are enteroendocrine cells predominantly found in the islets of Langerhans in the head of the pancreas. They are one of the four main endocrine cell types present in the pancreatic islets, along with type A, B and D cells. PP cells are notable for their production of pancreatic polypeptide, an anorexigenic hormone that modulates food intake and energy homeostasis. + +By secreting pancreatic polypeptide, PP cells play a significant role in the management of both digestive and appetite regulation. Upon ingestion of food, there is a significant increase in the secretion of pancreatic polypeptide, which then reduces biliary secretion and helps slow down the movement of food through the digestive tract. This allows more time for digestion to take place and nutrients to be absorbed, promoting the efficient use of dietary intake. The pancreatic polypeptide further reduces appetite by interacting with the hypothalamus, the area of the brain responsible for control of hunger. + +Given their important role in digestion, malfunction or damage to PP cells can lead to a disturbance in the digestive process and contribute to some disease conditions. For example, an overproduction of pancreatic polypeptide can result in conditions such as pancreatic tumors and diabetes. Conversely, an under secretion might contribute to obesity due to impaired dietary control. Furthermore, PP cells may also play a role in the body's energy balance, suggesting their implication in conditions related to energy metabolism. +" DOI:10.1369/00221554155835|DOI:10.1210/jc.2003-030630|DOI:10.1016/j.mce.2015.06.028|DOI:10.1016/j.febslet.2014.07.005|DOI:10.1038/s41580-020-00317-7 +CL:0000860 CL_0000860 "Classical monocytes are a subtype of monocytes that are characterized by high CD14 but no CD16 expression. Emerging from the bone marrow and entering the bloodstream, these cells play central roles in immune responses and regulation of inflammation. CD14-positive CD16-negative monocytes form the majority of circulating monocytes in the body, typically contributing to around 80-90% of the total monocyte pool. + +The primary function of the classical monocytes is to serve in the frontline of host defense against infections. They are primed to migrate to sites of infection, and they express pattern recognition receptors that help them identify and phagocytose pathogens, leading to their destruction. Classical monocytes also contribute to inflammation by producing several pro-inflammatory cytokines including interleukins and tumor necrosis factors. + +In response to specific signals from tissues under pathological conditions, such as infection or injury, classical monocytes can leave the bloodstream and migrate towards the affected sites. Following their arrival, these cells differentiate into diverse cell types including macrophages and dendritic cells to combat specific pathogens or injury. Dysregulated monocyte activity can lead to the development of many human diseases including inflammation, infection, tissue injury, and various autoimmune diseases. +" DOI:10.1111/sji.12883|DOI:10.3389/fimmu.2015.00423/full|DOI:10.1182/blood-2009-07-235028|DOI:10.3389/fimmu.2019.02035|DOI:10.1038/nri.2017.28 +CL:0000863 CL_0000863 "Inflammatory macrophages, also sometimes referred to as M1 or classically activated macrophages, play an important role in the inflammatory response. The M1/M2 classification is based upon macrophage polarization rather than macrophage location and refers to macrophage activation towards either a more inflammatory or more resolving phenotype, respectively, although the functional diversity of macrophages is more nuanced than such a dichotomy suggests. + +Inflammatory macrophages are derived from monocytes recruited to a site of infection or injury. M1 macrophages are classically activated, typically by IFN-γ or lipopolysaccharide (LPS). Upon sensing signs of inflammation, they quickly respond by increasing their pro-inflammatory activity. They achieve this by producing a range of signaling molecules, such as nitric oxide, reactive oxygen species, and numerous cytokines such as tumor necrosis factor-alpha (TNF-alpha) and interleukin-1, -6 and -12. The release of these potent molecules helps to recruit other immune cells to the site, killing off pathogenic organisms and facilitation inflammation. At the same time, M1 macrophages can also present antigens to T cells, thereby helping to induce an adaptive immune response. Over time, these macrophages may transition in phenotype and function to help resolve the inflammation and promote tissue repair. + +Despite the beneficial role of inflammatory macrophages in dealing with pathogens, chronic activation of these cells can lead to harmful effects. Over time, continuous production of pro-inflammatory molecules can cause damage to tissues and organs. This is seen in certain chronic inflammatory diseases, such as atherosclerosis, diabetes, obesity, asthma, and various autoimmune disorders. In such situations, the normally protective function of inflammatory macrophages is not properly controlled, which can contribute to disease pathology. +" DOI:10.1038/s41392-023-01452-1|DOI:10.1186/s12935-021-02089-2|DOI:10.3389/fimmu.2020.583084|DOI:10.3389/fimmu.2015.00263 +CL:0000890 CL_0000890 "Alternatively activated macrophages, also referred to as M2 macrophages, are immune cells originating from monocytes. The M1/M2 classification is based upon macrophage polarization rather than macrophage location and refers to macrophage activation towards either a more inflammatory or more resolving phenotype, respectively, although the functional diversity of macrophages is more nuanced than such a dichotomy suggests. + +M2 macrophages cells are differentiated from their precursors generally in response to Th2 cytokines, such as interleukin-4 (IL-4), interleukin-10 (IL-10), and interleukin-13 (IL-13). Tissue-resident macrophages are also sometimes said to have an “M2-like” phenotype. M2 macrophages play key roles in immunoregulation and disease resolution. + +Functionally, alternatively activated macrophages are essential in wound healing and tissue repair and remodeling, largely due to their potent anti-inflammatory actions and their ability to promote angiogenesis. They achieve these functions by the production of specific growth factors and signaling proteins including Arg1, Ym1/2, Fizz1, and TGF-β. Additionally, they provide defense against specific categories of pathogens, particularly parasites, through specific communication with Th2 cells. + +However, dysfunction of M2 macrophages can be harmful. Alternatively activated macrophages have been associated with several pathological conditions such as asthma, fibrosis, and tumor progression. This is due to their capacity to inhibit inflammatory responses, promote unneeded wound healing processes, and support tumour growth and spreading. Furthermore, complex roles have been observed in metabolic disorders, cardiovascular diseases, and neurodegenerative diseases, showing the diverse functional spectrum of these cells. +" DOI:10.1038/s41392-023-01452-1|DOI:10.1186/s12935-021-02089-2|DOI:10.3389/fimmu.2020.583084|DOI:10.3389/fimmu.2015.00263 +CL:0002064 CL_0002064 "Pancreatic acinar cells are the functional units of the exocrine pancreas. These cells are structurally arranged in small clusters - or acini - with a small central lumen, and their primary function is to produce and secrete enzymes that facilitate digestion of proteins, carbohydrates, and fats within the small intestine. + +Some of the most important digestive enzymes synthesized by the pancreatic acinar cells include amylase, which digests carbohydrates, lipase, which breaks down fats, and several proteases such as trypsin and chymotrypsin which are vital for the digestion of proteins. Importantly, these enzymes are produced as proenzymes or zymogens to avoid autolysis, or the breakdown of the pancreas itself. + +The release of these enzymes by the pancreatic acinar cells is strictly regulated by hormones and neurochemicals. Cholecystokinin (CCK) released from the enteroendocrine cells in the duodenum cause the release of these enzymes. Moreover, acinar cells also respond to another hormone, secretin, by releasing bicarbonate-rich fluid which helps to neutralize the gastric acid in the duodenum. + +Dysregulation in the function of pancreatic acinar cells can lead to severe health issues, including pancreatitis, which is characterized by inflammatory damage to the organ due to the premature activation of digestive enzymes. +" DOI:10.1097/01.mog.0000239863.96833.c0|DOI:10.1038/nrgastro.2013.36|DOI:10.1016/0165-6147(89)90192-2|https://www.ncbi.nlm.nih.gov/books/NBK54134/ +CL:0002067 CL_0002067 "Type A enteroendocrine cells, also known as alpha cells or A cells, are a species of endocrine cells primarily located in the pancreatic islets of Langerhans; they have also been identified within the lining of the stomach. Functionally, these cells are pivotal in glucose metabolism and homeostasis, accounting for about 20% of the total population of cells in the pancreatic islets. +The primary role of type A enteroendocrine cells involves the synthesis, storage, and secretion of the peptide hormone glucagon, which is critical in energy regulation throughout the body. In response to a decrease in blood glucose levels, the pancreatic A cells are stimulated to secrete glucagon into the bloodstream. Glucagon acts on its target cells, mainly in the liver, to stimulate glycogenolysis and gluconeogenesis processes, thereby increasing blood glucose levels back to normal. In this way, pancreatic A cells play an integral role in maintaining glucose homeostasis and preventing hypoglycemia. + +Pancreatic A cells also participate in the local regulation of islet activities as glucagon acts through glucagon receptors on A, B and D type cells within the islets. Recent studies have also shown that Pancreatic A cells play a role in the generation and regeneration of B type cells. Following beta cell injuries pancreatic A cells increase in numbers and produce Glucagon-like peptide-1 (GLP-1), which increases the proliferation and cytoprotection of beta cells. In response to extreme injury of B type cells pancreatic A cells can transform (transdifferentiate) into functioning B type cells. + +Until recently, glucagon has been considered a pancreas-specific hormone; however, extrapancreatic glucagon has been reported in patients who had undergone complete, and glucagon-positive cells been identified in the human stomach, indicating that Type A enteroendocrine cells are not restricted to the pancreas. +" DOI:10.2337/db15-1541|DOI:10.1016/j.diabres.2018.06.013|DOI:10.2337/dbi19-0002|DOI:10.3389/fphys.2012.00349/full|DOI:10.1210/en.2016-1748 +CL:0002145 CL_0002145 "Ciliated columnar cells of the tracheobronchial tree compose the inner lining of the tracheobronchial tree, the system of airways consisting of trachea, bronchi and bronchioles that allow passage of air into the lungs, where gas exchange occurs. A defining feature of these endo-epithelial cells are the tiny hair-like structures covering their surface, known as cilia. The nucleus is located at the base of the cell, and the area above it is rich in mitochondria and well-developed endoplasmic reticulum, both crucial for the energy-intensive process of cilia operation. + +The primary function of these ciliated cells is to keep the respiratory tract clean via mucociliary clearance or the respiratory escalator. These cells create a two-layered 'coat': The lower ""sol"" layer is watery where the cilia can beat in coordinated waves, and the upper ""gel"" layer is thick and sticky, trapping inhaled particles, such as dust, bacteria, viruses, and other potentially harmful substances. This rhythmical beating of the cilia then moves the mucus and trapped particles upwards and out of the respiratory tract, which is then either coughed out or swallowed. + +Damage or dysfunction of these ciliated cells, as seen in diseases such as primary ciliary dyskinesia, cystic fibrosis, or chronic bronchitis, may lead to reduced or ineffective mucociliary clearance and an increased susceptibility to respiratory infections." DOI:10.1101/cshperspect.a028241|DOI:10.1152/ajplung.00329.2019|DOI:10.1159/000196486|DOI:10.1146/annurev-physiol-021014-071931 +CL:0002204 CL_0002204 "Brush cells, also referred to as tuft cells or multivesicular cells, are a specialized type of epithelial cell mainly noted for their characteristic 'brush border' composed of microvilli. These cells reside in the epithelial lining of tissue organs such as the respiratory tract, gastrointestinal tract, and the bile ducts. The name derives from their distinct appearance under the microscope, which resembles a brush due to the dense layer of microvilli protruding into the lumen. + +A key function of brush cells is chemosensation: They express a variety of signaling molecules and receptors that enable them to detect specific chemical stimuli in the environment and act as sensory transducers. Many of these receptors are responsive to luminal content, which makes brush cells vital for regulating and coordinating appropriate physiological responses to changes in these substances. + +Recent research has also elucidated an important role for these cells in immunity. Intestinal brush cells have been found to be the source of a cytokine called interleukin-25, which can initiate type 2 immune responses during parasitic infections. This immune function, along with the chemosensing abilities, signifies that brush cells could serve crucial roles in health and disease, although much research is still required to fully elucidate their myriad roles in physiology and pathology. Overall, brush cells are a versatile cell type, whose distinct morphology and functional capabilities allow them to perform a unique set of functions within the body. + +" DOI:10.1111/j.1469-7580.2005.00403.x|DOI:10.1007/978-3-211-99390-3_83|DOI:10.5114/ceji.2022.124416|DOI:10.1038/nature16161|DOI:10.3389/fphys.2015.00087 +CL:0002225 CL_0002225 "Secondary lens fibers are a specialized type of elongated cells located within the structure of the eye's lens. They play an essential role in vision by enabling light transmission and focus on the retina, which allows for clear, distinct vision. These cells are characterized by their lack of nuclei and organelles, their orderly alignment, and their high protein content, particularly crystallins. + +Lens fibers are differentiated from equatorial epithelial cells of the lens in a process that involves cell elongation, denucleation and tight packing, which serve to reduce light scattering occurrences in the eye. This differentiation accelerates substantially after birth in comparison to during embryogenesis and continues throughout life, contributing to the growth of the eye lens. Secondary lens fibers are specifically those cells that are newly differentiated and cover the old lens fiber core. This process also leads to the removal of light-obstructing cellular components, mainly nuclei and organelles, making these fibers transparent and ideal for their function. + +The fibers carry out their primary function of light refraction via a high concentration of specialized proteins known as crystallins, which form a gradient of refractive index together with the cytoplasm. This index manipulation facilitates precise light focus onto the retina. Secondary lens fibers also contribute to the lens's shape and biomechanical properties through intercellular interactions, particularly at the sutures where the ends of the fibers meet. Any disruption to secondary lens fibers can lead to vision problems, including cataracts, which is the clouding of the lens resulting from the aggregation of crystallin proteins. +" https://www.sciencedirect.com/topics/immunology-and-microbiology/lens-fiber|DOI:10.1016/j.biocel.2007.10.034|DOI:10.1016/B978-1-4377-1926-0.10005-0|DOI:10.1098/rstb.2010.0324|DOI:10.1136/bmjophth-2020-000459 +CL:0000731 CL_0000731 "Urothelial cells are a unique type of epithelial cell found lining the urinary tract system. They form the urothelium, a specialized, multi-layered epithelium that lines major portions of the urinary tract, including the renal pelvis, ureters, bladder, and the proximal part of the urethra. The distinct characteristic of urothelial cells is their ability to stretch and contract depending on the volume of liquid they contain - a feature that facilitates the essential role they play in maintaining the functionality and integrity of the urinary system. + +The primary function of urothelial cells is to provide an impermeable barrier to urine, preventing the toxic components present in the urine from seeping back into the body's bloodstream. The urothelium consists of a superficial umbrella cell layer, 1–2 layers of intermediate cells, and a basal cell layer. The umbrella layer is composed of large, mostly binucleated cells that are covered in an asymmetrical unit membrane, the uroplakin plaques. These plaques function to seal the apical membrane of the bladder from the toxic and highly variable contents of urine. The lipid bilayer structure of uroplakin plaques has an exceptionally high concentration of uroplakins that contribute to the barrier function of the urothelium. + +Beyond their mechanical function, urothelial cells also play a role in sensing and signaling changes in the urinary system. They express a number of sensor molecules or respond to thermal, mechanical and chemical stimuli and can release chemical mediators. This allows them to act as sensory transducers because they detect changes in the filling state of the bladder and transmit this information to the nervous system. Moreover, these versatile cells contribute to the defense mechanism against urinary tract pathogens. They respond to bacterial infections by releasing chemical messengers, cytokines and chemokines, to attract immune cells, and also can engulf pathogens via endocytosis. + +" DOI:10.1152/physrev.00041.2019|DOI:10.1038/ki.2009.73|DOI:10.1038/ncpuro0672|DOI:10.1038/s41579-020-0324-0|DOI:10.1002/nau.22195 +CL:0002329 CL_0002329 "The basal epithelial cells of the tracheobronchial tree are critical components found in the lining of the airway passages, including the trachea and bronchi. They are keratin-5-positive, nonciliated, cuboidal cells and typically tightly attached to the basement membrane. In humans, the proportion of basal cells in the respiratory epithelium gradually decreases going down the tracheobronchial tree: they represent approximately 34% of the cells in the trachea, 27% in the large airways, and 10% in the small airways, although it is worth noting that there are differences in the compositions of the tracheobronchial epithelia between different species. + +Basal epithelial cells serve as the basal layer of the tracheobronchial epithelium, providing both structural and regenerative support for the epithelial tissue that lines the upper regions of the respiratory tract. They serve as progenitor or stem cells that are capable of differentiating into multiple cell types, such as ciliated and secretory cells. This gives them a central role in homeostatic maintenance of the epithelium, and in repairing damaged epithelium after an injury or during disease. This regenerative capacity is crucial in maintaining the integrity of the tracheobronchial surface, especially given its continual exposure to inhaled irritants and microorganisms. + +In addition to their primary restorative function, basal epithelial cells are also involved in the initial immune response within the tracheobronchial tree. Equipped with pattern recognition receptors, these cells can identify and respond to pathogenic organisms, triggering an immune response and producing a range of inflammatory mediators, such as cytokines and chemokines, to help combat infections. +" DOI:10.1165/rcmb.2013-0049OC|DOI:10.1186/s12931-014-0160-8|DOI:10.2353/ajpath.2010.090870 +CL:0002370 CL_0002370 "The respiratory goblet cell is a highly specialized cell type found primarily within the respiratory tract, including the nose, trachea, and lungs. Named because their shape resembles a goblet - a drinking vessel with a wide body and narrow neck - these cells form a vital part of the respiratory system's protective mechanisms. They are found within the columnar epithelium lining these organs, which forms a barrier between the internal body and the exterior environment. + +A principal function of the respiratory goblet cell is the production and secretion of mucus, a carbohydrate-rich, viscous and gel-like substance that plays a critical role in trapping dust, bacteria, viruses, and other airborne particles that are inhaled. The mucus secreted by the goblet cells covers the lining of the respiratory tract, effectively catching these particles and preventing them from reaching the lungs and causing infection. Mucus also provides hydration and lubrication to the respiratory tract surfaces, which is important in maintaining the tissue's health and functioning. + +In addition to their mucus-secreting capabilities, respiratory goblet cells also play a significant role in the body's inflammatory responses. When the respiratory system is exposed to irritants or pathogens, the number and activity of goblet cells often increase, leading to a higher production of mucus. This is a protective response designed to trap and neutralize the harmful substances more effectively. However, in conditions like chronic obstructive pulmonary disease (COPD) and asthma, an overproliferation of goblet cells, also known as goblet cell hyperplasia, can lead to excessive mucus production and airway obstruction." DOI:10.1016/S1357-2725(02)00083-3|DOI:10.1165/ajrcmb.25.5.f218|DOI:10.2147/COPD.S38938|DOI:10.3109/01902148.2013.791733|DOI:10.1111/febs.15731 +CL:0002570 CL_0002570 "Mesenchymal stem cells of adipose tissue, also known commonly as adipose-derived stem cells (ADSCs), are a population of adult stem cells that can be obtained easily from adipose tissues. They have many of the same regenerative properties as other mesenchymal stem cells, but are more easily accessible than bone marrow-derived stem cells. + +Adipose-derived stem cells show immense promise in the field of regenerative medicine due to their ability to differentiate into adipocytes, chondrocytes, myocytes, osteoblasts, and other cell types. ADSCs also possess immunomodulatory and homeostatic functions: they have the ability to suppress immune responses and provide a therapeutic environment for tissue repair and regeneration, as well as supporting the proliferation of adipocytes and the overall expansion of adipose tissue and contributing to the tissue's ability to react to demands of energy storage and mobilization. Dysfunction of these cells may contribute to metabolic complications observed in obesity and diabetes. + +ADSCs have been used for therapeutic applications such as pathological wound healing, severe refractory acute graft-versus-host disease, and idiopathic thrombocytopenic purpura." DOI:10.1038/s41536-019-0083-6|DOI:10.1016/j.biopha.2019.108765|DOI:10.1016/j.tibtech.2006.01.010|DOI:10.1111/dgd.12049|DOI:10.1096/fj.202100332R +CL:0002586 CL_0002586 "Retinal pigment epithelial (RPE) cells form a single layer of cells at the back of the eye sandwiched between the neurosensory retina and the choroid, playing a significant role in maintaining vision health. These pigment-laden cells are highly specialized and perform an array of metabolic and transport functions essential for the maintenance of the photoreceptor cells (rods and cones) in the retina. The pigmentation of RPE cells actively aids in the absorption of excess light and the prevention of light scattering, thus enhancing the eye's optical properties. + +The retinal pigment epithelium forms a key part of the blood/retina barrier. The cells have long sheet-like microvilli on their apical membrane that project into the light-sensitive outer segments of the photoreceptors, forming a close structural interaction. The basolateral membrane of the RPE interacts with the underlying Bruch’s membrane, which separates the RPE cells from fenestrated endothelium of the choriocapillaris. + +RPE cells support the photoreceptor by providing them with oxygen and nutrients (such as glucose, retinol and fatty acids) and removing waste products. They also recycle the visual pigment, in a process called the ""visual cycle"", where the RPE cells play a vital role in the regeneration of visual pigment (11-cis retinol) following the absorption of light. This is essential for the maintenance of photoreceptor excitability. + +Beyond this, RPE cells take part in the phagocytosis process, where they digest the shed ends of photoreceptor outer segments, thus, preventing the build-up of waste residue that could otherwise harm retinal health. They also secrete various factors, including growth factors required to maintain the structural integrity of choriocapillaris endothelium and photoreceptors, as well as immunosuppressive factors that play an important role in establishing the immune privilege of the eye. + +" DOI:10.3389/fphar.2021.727870/full|https://www.sciencedirect.com/topics/chemistry/retinal-pigment|DOI:10.1152/physrev.00021.2004|DOI:10.1111/febs.16018 +CL:0002633 CL_0002633 "Respiratory basal cells are highly specialized cells that serve a crucial role in the human airway epithelium, predominantly found lining the surfaces of the trachea and bronchi. These cells exhibit a distinctive columnar shape and are attached directly to the basal lamina. They are characterized by the presence of high amounts of cytoplasmic keratins, predominantly keratin 5 and 14, and transcription factor tumor protein (tp63), which set them apart from other types of lung epithelial cells such as ciliated cells and secretory cells. + +Basal cells are essential for maintaining airway integrity. They make up one third of all respiratory epithelial cells and serve as stem cells as they can transform into different cell types, like goblet cells, ciliated cells, and club cells, when needed for homeostatic maintenance of the epithelial barrier or to repair and restore a healthy cellular environment after injury. + +Their position at the interface between the internal environment and the external atmosphere makes these cells a first line of defense against air-borne irritants, allergens, and pathogens. Their robust, intrinsic reparative properties facilitate effective recovery from such adversities. However, damage to respiratory basal cells or abnormalities in their function are associated with several respiratory pathologies such as asthma, chronic obstructive pulmonary disease, and lung cancer. Therefore, understanding these cells' function, and their role in disease, is crucial for the development of new therapeutic strategies for respiratory disorders. +" DOI:10.3389/falgy.2021.787128|DOI:10.1186/s12931-022-02042-5|DOI:110.1038/s41385-020-00370-7 +CL:0005006 CL_0005006 "Ionocytes are specialized cells predominantly found in the mammalian respiratory and renal systems as well as in the gills, skin, and intestinal tract of fish. These cells play crucial roles in maintaining ion and acid-base homeostasis. Ionocytes demonstrate remarkable plasticity and are able to adapt themselves in response to changes in environmental conditions such as pH, salinity, ion concentration, and temperature. + +These cells work by selectively absorbing specific ions from the environment, thus maintaining the body's internal ionic balance. The most commonly absorbed ions include sodium (Na+), chloride (Cl-), calcium (Ca2+), and hydrogen (H+). Moreover, ionocytes contribute to acid-base regulation. In response to acidosis or alkalosis, ionocytes can either excrete or retain hydrogen (H+) and bicarbonate (HCO3-) ions to readjust the blood pH. Further, experimental evidence suggests a functional complexity of ionocytes, implying diverse roles beyond ion regulation. Recent research highlights ionocytes' involvement in ammonia excretion and the regulation of extracellular fluid volume, highlighting their contribution to the overall homeostatic process. + +Malfunctioning ionocytes have been implicated in various diseases, including cystic fibrosis which is caused by mutations in the chloride channel CFTR, an ionocyte marker. +" DOI:10.1146/annurev-pathol-042420-094031|DOI:10.1016/j.jcf.2019.09.010|DOI:10.1038/s41586-018-0393-7|DOI:10.1038/s41598-023-30603-1|DOI:10.3389/fmars.2020.00709 +CL:0005012 CL_0005012 "The multi-ciliated epithelial cell are terminally differentiated epithelia that line brain ventricles, the respiratory tract and parts of the female and male reproductive organs in animals, playing critical roles in the maintenance of homeostasis through ciliary motion. They are characterized by the presence of hundreds of motile cilia, hair-like microtubule-based organelles that beat in a coordinated fashion to direct fluid flow over the cell surface. + +Multi-ciliated epithelial cells have fundamental roles in the proper functioning of many organ systems. In the respiratory system, they line the airways and orchestrate the coordinated movement of mucus, effectively clearing the airways of inhaled particles and pathogens. These cells are also vital in the ventricular system of the brain where they facilitate cerebrospinal fluid circulation, thus contributing to the maintenance of the brain's microenvironment. In the fallopian tube, multi-ciliated epithelial cells aid in the transport of oocytes from the ovary to the uterus, a process crucial to reproduction. + +The formation and function of multi-ciliated epithelial cells is a highly regulated process that involves several stages of development including cell specification, centriole multiplication, and ciliogenesis. Any disruption in these processes can result in dysfunctional or decreased numbers of cilia, which can lead to a myriad of health issues, ranging from chronic respiratory infections to infertility. " DOI:10.1016/j.cub.2014.08.047|DOI:10.1101/cshperspect.a028233|DOI:10.1038/nrm.2017.21 diff --git a/src/patterns/data/source_data/CellGuide/CG_desc_proc.py b/src/patterns/data/source_data/CellGuide/CG_desc_proc.py new file mode 100644 index 000000000..1bf44aadd --- /dev/null +++ b/src/patterns/data/source_data/CellGuide/CG_desc_proc.py @@ -0,0 +1,26 @@ +import pandas as pd +cg_desc = pd.read_excel('./CellGuide Validated Descriptions for CL Review.xlsx') +cg_desc.fillna('', inplace=True) +rows = [] +rejects = 0 +for i,r in cg_desc.iterrows(): + print(bool(r['For CL inclusion'])) + if not (r['For CL inclusion']): + if r['For CL inclusion'] == 0: + rejects += 1 + continue + row = {'defined_class': r['CL ID'], 'CL_short_form': str(r['CL ID']).replace(':', '_'), + 'desc': r["Final version (QC'd)"], 'pubs': ''} + pub_list = [] + for k,v in r.items(): + if str(k).startswith('Supporting'): + if str(v).startswith('http'): + pub_list.append(v) + elif(v): + pub_list.append('DOI:' + v) + row['pubs'] = '|'.join(pub_list) + rows.append(row) +print("Added %d extended defs" % len(rows)) +print("Rejected descriptions %d" % rejects) +out = pd.DataFrame.from_records(rows) +out.to_csv('../../default/ExtendedDescription.tsv', sep='\t', index=False) \ No newline at end of file diff --git a/src/patterns/data/source_data/CellGuide/CellGuide Validated Descriptions for CL Review.xlsx b/src/patterns/data/source_data/CellGuide/CellGuide Validated Descriptions for CL Review.xlsx new file mode 100644 index 000000000..8a7623046 Binary files /dev/null and b/src/patterns/data/source_data/CellGuide/CellGuide Validated Descriptions for CL Review.xlsx differ diff --git a/src/patterns/definitions.owl b/src/patterns/definitions.owl index ac601893e..ab548fb6b 100644 --- a/src/patterns/definitions.owl +++ b/src/patterns/definitions.owl @@ -7,8 +7,8 @@ Prefix(rdfs:=) Ontology( - -Annotation(owl:versionInfo "2024-08-19") + +Annotation(owl:versionInfo "2024-09-09") Declaration(Class()) Declaration(Class()) @@ -45,11 +45,11 @@ Declaration(Class()) Declaration(Class()) Declaration(Class()) Declaration(Class()) +Declaration(Class()) Declaration(Class()) Declaration(Class()) Declaration(Class()) Declaration(Class()) -Declaration(Class()) Declaration(Class()) Declaration(Class()) Declaration(ObjectProperty()) @@ -57,6 +57,7 @@ Declaration(ObjectProperty()) Declaration(AnnotationProperty()) Declaration(AnnotationProperty()) Declaration(AnnotationProperty()) +Declaration(AnnotationProperty()) Declaration(AnnotationProperty()) Declaration(AnnotationProperty()) @@ -66,6 +67,44 @@ Declaration(AnnotationProperty( () + +AnnotationAssertion(Annotation( "DOI:10.1016/j.coi.2005.11.008") Annotation( "DOI:10.1038/nri3087") Annotation( "DOI:10.3389/fimmu.2019.01893") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Mononuclear phagocytes are immune cells that form a critical part of the body's innate immune system, the body's first line of defense against infections. Mononuclear phagocytes are characterized by the presence of a single, large nucleus. The ‘Mononuclear Phagocyte System’ nomenclature was introduced to distinguish mononuclear monocytes and macrophages from other cells with multiple nuclei. However, the cells within the mononuclear phagocyte system represent a highly heterogeneous group, all of which are able to perform highly efficient phagocytosis - engulfing and digesting microbes and cellular debris to fight infections and to maintain normal tissue homeostasis. +In addition to phagocytosis, mononuclear phagocytes also secrete chemical compounds to recruit other immune cells to a site of infection. These cells produce different types of signaling molecules, including cytokines, chemokines, and reactive oxygen species, triggering a cascade of responses to ensure rapid and efficient containment and neutralization of invading pathogens. These cells are also involved in antigen presentation, a process essential for stimulating an adaptive immune response. They can process and present antigens to T cells, thereby linking the innate and adaptive immune responses. +Mononuclear phagocytes play key roles in tissue repair and remodeling. After infection or injury, these cells help in the clearance of dead cells and debris, a crucial step in the initiation of tissue remodeling and the resolution of inflammation. Overall, mononuclear phagocytes are versatile cells that have tailored their functions to meet the unique challenges of different tissues within the body. They are pivotal in homeostasis, immunity, and inflammation, making them important aspects in a range of human diseases including infection, autoimmunity, and cancer.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0000113") + +# Class: () + +AnnotationAssertion(Annotation( "DOI:10.1002/glia.24343") Annotation( "DOI:10.1038/nn1988") Annotation( "DOI:10.1101/cshperspect.a020602") Annotation( "DOI:10.1126/science.aat0473") Annotation( "DOI:10.3389/fncel.2017.00024") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Glial cells, also known as neuroglia or simply glia, are non-neuronal cells in the central and peripheral nervous systems that provide support and protection for neurons. They constitute approximately half of the total cells in the human brain and more than half in other parts of the nervous system. Glial cells perform several key functions including, but not limited to, maintaining homeostasis, forming the myelin sheath around the neuron axons, and providing support and nutrition to neurons. +These different functions are performed by various glial cell types, including astrocytes, oligodendrocytes, microglia and other specialized types. Astrocytes, for example, are the most abundant glial cells and provide metabolic and nutrient support to neurons, help regulate the extracellular ion and neurotransmitter levels, and play a role in the formation and maintenance of the blood-brain barrier, contributing to the overall homeostasis and functioning of the nervous system. Additionally, astrocytes are involved in synaptic communication and participate in processes such as synaptogenesis and synaptic pruning. +Oligodendrocytes in the central nervous system function to insulate neurons by producing a fatty substance known as myelin. The myelin sheath enhances the speed and efficiency of nerve impulse conduction along the axons. +Microglia, the immune cells of the central nervous system, protect neurons from pathogens and clear away dead neurons through phagocytosis, a process also known as cellular eating. They also contribute to the regulation of inflammation in response to signals of tissue damage or infection in the central nervous system by releasing cytokines and other signaling molecules that modulate the immune response. +Despite their overarching function in the support and protection of neurons, glial cells have also been shown to play significant roles in the pathophysiology of many psychiatric and neurodegenerative diseases, such as Alzheimer’s, Parkinson’s Disease and multiple sclerosis.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0000125") + +# Class: () + +AnnotationAssertion(Annotation( "DOI:10.1016/0166-4328(96)00075-7") Annotation( "DOI:10.1016/j.cell.2017.05.034") Annotation( "DOI:10.1038/s41574-019-0168-8") Annotation( "DOI:10.1073/pnas.1804938115") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Type EC enteroendocrine cells, also known as enterochromaffin cells, are a vital hormone-secreting cell type found in the gastrointestinal tract. These cells are named after their location in the intestines (“entero”) and because they are stainable by chromium salts (“chromaffin”). +The primary function of type EC enteroendocrine cells is to act as chemosensors and lies in their capacity to produce and secrete serotonin, also known as 5-hydroxytryptamine (5-HT). Serotonin is a neurotransmitter that plays a significant role in modulating motility, secretion, vasodilation, perception of pain, and appetite in the gastrointestinal system. However, its function is not limited to the gastrointestinal tract; once secreted, serotonin is distributed via the bloodstream and contributes to regulating mood, appetite, and sleep in the brain. +Via specific chemosensory receptors type EC enteroendocrine cells are able to respond to various environmental, metabolic, and homeostatic stimuli and transduce information from the gut to the nervous system: Food intake, particularly the ingestion of fats and carbohydrates, prompts these cells to produce and release serotonin; the mechanical stimulus of food in the lumen can also trigger release. The distribution, function, and responsiveness of type EC cells reveal them as a crucial link between the intestinal environment, the nervous system, and the regulation of numerous bodily functions.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0000577") + +# Class: () + +AnnotationAssertion(Annotation( "DOI:10.1007/s00424-017-1965-3") Annotation( "DOI:10.1016/j.cellimm.2018.01.005") Annotation( "DOI:10.1038/nri3600") Annotation( "DOI:10.14348/molcells.2021.0058") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Alveolar macrophages are unique tissue-resident macrophages found in the lungs, specifically in the air sacs or alveoli where gas exchange occurs. They are characterized by specific surface markers including: F4/80-positive, CD11b-/low, CD11c-positive, CD68-positive, sialoadhesin-positive, dectin-1-positive, MR-positive, CX3CR1-negative. These specialized immune cells form a crucial part of the body's defense mechanism, playing important roles in pulmonary health and homeostasis. They are the first line of defense in the pulmonary immune response, acting as scavengers that patrol the alveoli and engulf foreign particles like bacteria, dust, and other debris that enter the lungs through inhalation. +The primary function of these alveolar macrophages is phagocytosis, whereby they consume and digest foreign substances, dead cells, and other particulates. In the lung, alveolar macrophages are also responsible for clearing surfactant. Additionally, alveolar macrophages also play an integral role in initiating the immune response, as they secrete several pro-inflammatory cytokines and chemokines that recruit other immune cells to the site of infection or inflammation. +Beyond their role in host defense, alveolar macrophages contribute to tissue remodeling and wound repair in the lungs, aiding in maintaining lung integrity. They also regulate local inflammation and control the immune response to prevent excessive inflammation that may be harmful. However, an imbalance in the function of alveolar macrophages can contribute to various lung diseases. Abnormal alveolar macrophage activation has been implicated in chronic inflammatory diseases such as emphysema, asthma, and fibrosis.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0000583") + # Class: (cycling B cell) AnnotationAssertion(Annotation( "PMID:31348891") "A(n) B cell that is cycling.") @@ -201,6 +240,15 @@ AnnotationAssertion(Annotation( "cycling basal cell") EquivalentClasses( ObjectIntersectionOf( ObjectSomeValuesFrom( ) ObjectSomeValuesFrom( ))) +# Class: (cycling stromal cell) + +AnnotationAssertion(Annotation( "PMID:34497389") "A(n) stromal cell that is cycling.") +AnnotationAssertion( ) +AnnotationAssertion( "2024-07-19T09:14:23Z") +AnnotationAssertion(Annotation( "PMID:34497389") "proliferating stromal cell") +AnnotationAssertion(rdfs:label "cycling stromal cell") +EquivalentClasses( ObjectIntersectionOf( ObjectSomeValuesFrom( ) ObjectSomeValuesFrom( ))) + # Class: (cycling glial cell) AnnotationAssertion(Annotation( "PMID:34497389") "A(n) glial cell that is cycling.") @@ -237,14 +285,423 @@ AnnotationAssertion(Annotation( "cycling neuroblast (sensu Vertebrata)") EquivalentClasses( ObjectIntersectionOf( ObjectSomeValuesFrom( ) ObjectSomeValuesFrom( ))) -# Class: (cycling stromal cell) - -AnnotationAssertion(Annotation( "PMID:34497389") "A(n) stromal cell that is cycling.") -AnnotationAssertion( ) -AnnotationAssertion( "2024-07-19T09:14:23Z") -AnnotationAssertion(Annotation( "PMID:34497389") "proliferating stromal cell") -AnnotationAssertion(rdfs:label "cycling stromal cell") -EquivalentClasses( ObjectIntersectionOf( ObjectSomeValuesFrom( ) ObjectSomeValuesFrom( ))) - +AnnotationAssertion(Annotation( "DOI:10.1002/cphy.c120026") Annotation( "DOI:10.1007/978-1-4939-1311-4_10") Annotation( "DOI:10.1016/j.immuni.2022.08.002") Annotation( "DOI:10.1038/nri.2017.11") Annotation( "DOI:10.1111/j.1478-3231.2006.01342.x") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Kupffer cells are tissue-resident macrophages located in the liver. They are an integral part of the mononuclear phagocyte system and are responsible for the phagocytosis of dead or dying cells, microbes, and other foreign substances. Kupffer cells account for approximately 80-90% of tissue-resident macrophages in the body. They are found within the lumen of liver sinusoids and interface with microbial populations and products. +The primary role of Kupffer cells is to maintain homeostasis in the liver. They continuously filter and cleanse the blood that flows through the liver, removing pathogens, endotoxins, particulate matter, aged and dysfunctional red blood cells, and miscellaneous waste products. These cells also play an important role in maintaining iron homeostasis. During the process of phagocytosis, Kupffer cells recycle iron from degraded red blood cells, which is then utilized in the formation of new erythrocytes. +Kupffer cells also play key roles in various immune responses and inflammatory processes. They secrete various types of cytokines and chemokines, which contribute to the activation and mobilization of other immune cells. They can also produce reactive oxygen species and nitric oxide, which have microbicidal actions. Although their activity is essential for host defense, excessive or prolonged activation of Kupffer cells may contribute to hepatic injury, inflammation, and fibrosis.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0000091") +AnnotationAssertion(Annotation( "DOI:10.1007/s12311-018-0985-7") Annotation( "DOI:10.1038/nrn3886") Annotation( "DOI:10.7554/eLife.63668") Annotation( "https://www.ncbi.nlm.nih.gov/books/NBK545154/") Annotation( "https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/purkinje-cell") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Purkinje cells, named after the Czech anatomist Jan Evangelista Purkyně who discovered them, are unique inhibitory neurons in the cerebellar cortex. They are a critical part of the vertebrate nervous system as they provide the only signal output from the cortex to the cerebellar nuclei. They are one of the few types of neurons that are large enough to be seen with the naked eye. The most distinct hallmark of Purkinje cells is their elaborate dendritic arbor, which forms a broad and intricately branching structure resembling a tree. These numerous branches each receive excitatory synaptic inputs from more than 100,000 parallel fibers; in addition, a single climbing fiber makes hundreds of synapses to the soma and proximal dendrites. A single long axon forms an inhibitory projection to the cerebellar nuclei. +Purkinje cells play key roles in the coordination of fine, voluntary motor movements and balance. As the sole output of all motor coordination in the cerebellar cortex, they serve as a central relay in the cerebro-cerebellar loop. Each Purkinje cell receives two types of synaptic input: one from parallel fibers (which are axons of granule cells), and the other from climbing fibers (originating from the inferior olivary nucleus). The Purkinje cells process and integrate these diverse kinds of input signals to generate output that controls timing and coordination of movements. +Purkinje neurons show considerable synaptic plasticity. Throughout life, these cells continue to undergo long-term potentiation and depression at parallel fiber synapses, which cause long-lasting increase or decrease, respectively, of synaptic transmission and have been proposed as mechanisms for motor learning. +Purkinje cells are also known to be implicated in a variety of diseases. Their progressive loss is a prime feature in certain types of ataxia, a collective term used to describe conditions characterized by loss of muscular control and coordination. Furthermore, a significant reduction in the density of Purkinje cells has been reported in conditions such as autism and Huntington’s disease.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0000121") +AnnotationAssertion(Annotation( "DOI:10.1016/S1357-2725(02)00083-3") Annotation( "DOI:10.1038/s41575-022-00675-x") Annotation( "DOI:10.1165/ajrcmb.25.5.f218") Annotation( "DOI:10.1242/bio.20121701") Annotation( "https://www.ncbi.nlm.nih.gov/books/NBK553208/") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Goblet cells are specialized, simple columnar, secretory epithelial cells that are mostly found in the respiratory and intestinal tracts. The term \"goblet\" refers to their shape, which resembles a flask or goblet, specially at their apical end which is swollen due to the accumulation of secretory granules. +The primary function of goblet cells is to to protect and lubricate the underlying tissues by secreting large quantities of mucin, a complex glycoprotein, which forms mucus when hydrated. In the respiratory tract, the mucus secreted by these cells traps dust, bacteria, viruses, and other potentially harmful particles in the inhaled air, preventing them from reaching the delicate tissues of the lungs. In the intestines, the goblet cells secrete mucus that acts as a protective barrier shielding the intestinal epithelium from dietary antigens, pathogens and prevents the intestinal epithelium from being eroded by the actions of the digestive enzymes and the abrasive action of passing food material. +Goblet cells are capable of rapidly altering their secretory output in response to stimuli. For example, irritants like smoke or dust can trigger an increased rate of mucus production, as the body attempts to flush out the harmful particles. Conversely, in conditions such as chronic bronchitis and cystic fibrosis, overactive goblet cells can create a thick accumulation of mucus that obstructs the airways and fosters bacterial growth. Lastly, goblet cells are not static, rather, they undergo a dynamic process known as goblet cell metaplasia-differentiation, wherein non-goblet cells in response to chronic injury or inflammation, can differentiate into goblet cells leading to an accumulation of these cells in the tissue, known as goblet cell hyperplasia.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0000160") +AnnotationAssertion(Annotation( "DOI:10.1038/s41574-019-0168-8") Annotation( "DOI:10.1111/j.1463-1326.2011.01438.x") Annotation( "DOI:10.1196/annals.1294.001") Annotation( "DOI:10.1210/endrev/bnaa018") Annotation( "DOI:10.7554/elife.78512") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Enteroendocrine cells are a specialized subset of cells located within the epithelial lining of both the small and large intestines, as well as the stomach and pancreas. Constituting less than 1% of the total population of intestinal cells, they are differentiated from a common intestinal cell progenitor, thus sharing lineage with absorptive and goblet cells of the intestines. +The distinct characteristic feature of an enteroendocrine cell is its inherent capacity to synthesize and secrete a plethora of gut hormones such as serotonin, somatostatin, neurotensin, cholecystokinin, secretin, gastric inhibitory peptide, motilin, and glucagon-like peptide-1. Integrated within this complex network of signaling agents, these substances control various aspects of the digestive system. Each enteroendocrine cell has its unique combination of hormones to release, determined by its position along the intestinal tract. Intriguingly, these hormones not only modulate local gut function, including motility, absorption and secretion, but also potentiate distant actions on other systems such as endocrine, nervous and immune and play a role in the feeling of satiety. +The release of these hormones from enteroendocrine cells is a highly regulated and dynamic process. The cells are equipped with sensory receptors localized on its luminal side that respond to various stimuli, including changes in nutrient composition, chemical or mechanical changes in the gut lumen, or even signals arising from commensal microbiota. This sensory input stimulates a signaling cascade within the cell, culminating in the release of specific hormones into the interstitial fluid. These hormones then make their way into the bloodstream, acting on their respective target receptors to mediate their duties. The multifunctional characteristics of enteroendocrine cells make them crucial for maintaining gut homeostasis and the overall physiological well being of the body.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0000164") +AnnotationAssertion(Annotation( "DOI:10.1002/cphy.c190003") Annotation( "DOI:10.1016/j.biocel.2016.02.003") Annotation( "DOI:10.3389/fendo.2018.00711") Annotation( "DOI:10.3389/fimmu.2022.977175") Annotation( "DOI:10.3389/fimmu.2022.977175/full") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Chromaffin cells, also known as pheochromocytes, are neuroendocrine cells that are typically located in the adrenal medulla, the innermost part of the adrenal gland, which is situated on top of each kidney. Chromaffin cells are also found in small clusters, known as paraganglia, in various locations throughout the body, including the sympathetic nervous system. They derive their name from their ability to stain a brownish-black color upon exposure to chromic salts, a feature made possible due to their high content of granules rich in catecholamines and catecholamine-related neurotransmitters. +The primary function of chromaffin cells is the synthesis and release of catecholamines, specifically epinephrine (adrenaline) and norepinephrine (noradrenaline). These neurotransmitters are vital stress hormones that, when released by the adrenal chromaffing cells into the bloodstream, prepare the body for the 'fight or flight' response. This response can enhance the body's performance in a dangerous situation by increasing heart rate, elevating blood sugar, and increasing blood flow to the muscles. The chromaffin cells in paraganglia are responsible for the local release of catecholamines and play a role in regulating blood pressure and other autonomic functions. +In addition to their role in stress response, chromaffin cells also contribute to the body's immune response. They secrete several peptides including antimicrobial peptides, and the discovery of LPS and cytokine receptors on chromaffin cells suggests that the adrenal medulla may participate in some aspects of the immune response.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0000166") +AnnotationAssertion(Annotation( "DOI:10.1016/j.coemr.2019.03.001") Annotation( "DOI:10.1093/biolre/ioy059") Annotation( "DOI:10.1210/clinem/dgaa603") Annotation( "DOI:10.3389/fendo.2014.00006") Annotation( "https://www.ncbi.nlm.nih.gov/books/NBK556007/#:~:text=Leydig%20cells%20are%20the%20primary,secondary%20sexual%20characteristics%20and%20behaviors.") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Leydig cells are a testosterone-secreting cell in the interstitial area in the testes of males. They are named after Franz Leydig, a German anatomist who discovered these cells in 1850. Uniquely situated within the soft connective tissue surrounding the seminiferous tubules, Leydig cells form an integral part of the male reproductive system. They are usually polygonal cells characterized by well developed smooth endoplasmic reticulum, high lipid content and a large round nucleus. They are found across mammalian species, including humans. +The primary function of Leydig cells is the production of androgens, the male sex hormones, the most notable of which is testosterone. Leydig cells synthesize testosterone from cholesterol through a series of enzymatic reactions. The production and release of testosterone are mainly regulated by the luteinizing hormone (LH) released by the anterior pituitary gland. In response to LH, Leydig cells convert cholesterol into testosterone, which then plays a crucial role in the development and maintenance of primary and secondary male sexual characteristics. These include the formation and maturation of male reproductive organs, onset of spermatogenesis, and the presentation of male secondary sexual traits such as the deepening of the voice, growth of facial hair, development of muscles, and a broadening of shoulders. +Apart from testosterone production, Leydig cells also secrete insulin-like factor 3 (INSL3) that is essential for testicular descent during embryonic development in males. Dysregulation or loss of Leydig cells can lead to numerous conditions like testosterone deficiency, infertility, and certain forms of testicular cancer. Although not typical, Leydig cells can regenerate if they are damaged, ensuring the continuous production of testosterone and maintaining male reproductive health. They provide an excellent model to study cell differentiation and hormone regulation, thereby enhancing our understanding of reproductive biology and associated disorders.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0000178") +AnnotationAssertion(Annotation( "DOI:10.1016/j.biocel.2011.11.011") Annotation( "DOI:10.1055/s-2007-1007096") Annotation( "DOI:10.1083/jcb.201903090") Annotation( "DOI:10.1111/j.1439-0396.2007.00752.x") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Hepatocytes are the major cell type constituting 70-80% of the liver's cytoplasmic mass, playing crucial roles in maintaining the body's metabolic homeostasis. Dimensions of mature hepatocytes typically range from 20 to 30 μm in humans, but size may vary depending on their location within the liver lobule. Hepatocytes are characterized by high biosynthetic, enzymatic, and endocytic activity. They contain abundant mitochondria, smooth and rough endoplasmic reticulum, peroxisomes, lysosomes, and a large nucleus that is often binucleate. +The liver consists of three zones - the periportal Zone 1, midzone 2, and pericentral Zone 3 - which have differential nutrient and oxygen status, and damage susceptibility; hepatocytes in the different zones show signifcant functional heterogeneity ('hepatocyte functional zonation'). Hepatocytes are involved in a multitude of critical functions including the metabolism of lipids, carbohydrates, and proteins, the synthesis of serum proteins (e.g., albumin, transferrin, and lipoproteins), the detoxification and excretion of endogenous and exogenous substances, the storage of vitamins and minerals, and the production and secretion of bile. +Heterocytes demonstrate a remarkable regenerative capacity, which enables the liver to recover from injury and loss of tissue mass. Notably, hepatocytes perform biotransformation with both phase I and phase II enzymes, which modify drugs, xenobiotics, and various substances for elimination from the body. Phase I enzymes, such as cytochrome P450, catalyze both oxidative and reductive reactions of many xenobiotics; many of the products of phase I enzymes are substrates for the phase II enzymes, which catalyze conjugation reactions. +Alterations in hepatocyte function have significant implications for overall human health and disease. Certain conditions, such as hepatitis, cirrhosis, and liver cancer, can profoundly affect hepatocyte structure and function, thereby disrupting the liver's ability to perform its vital roles within the body. As the primary site for drug metabolism, changes in hepatocyte function can also impact the effectiveness and toxicity of pharmaceuticals. The regenerative ability of hepatocytes makes them valuable cells for liver regenerative medicine and bioartificial liver support systems, and their study has provided significant insights into liver biology and disease.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0000182") +AnnotationAssertion(Annotation( "DOI:10.1016/j.ejogrb.2004.01.010") Annotation( "DOI:10.1093/humrep/del408") Annotation( "DOI:10.1093/humupd/6.3.279") Annotation( "DOI:10.1210/jcem-28-3-355") Annotation( "DOI:10.3389/fendo.2019.00832/full") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Granulosa cells are a type of somatic cell most commonly known for their crucial role within the ovarian follicles of female mammalian species. Named for their grainy appearance, they are situated in the follicular epithelium, lining the inner part of the follicle and directly surrounding the oocyte. These cells stand as an integral part of the ovarian structure and function. +One of the primary roles of granulosa cells is to aid in the production and secretion of sex hormones, particularly estrogen. They achieve this by working in tandem with theca cells, which stay attached to the external layer of the follicle. Theca cells produce androstenedione (a type of androgen) which granulosa cells then convert into estradiol, a form of estrogen, with the help of the enzyme aromatase. Moreover, granulosa cells participate in luteinization, transforming into luteal granulosa cells as a response to the luteinizing hormone during ovulation. This allows the formation of the corpus luteum, responsible for the secretion of progesterone necessary to maintain pregnancy. +Granulosa cells also play a significant role in follicular development and oocyte maturation, involving close communication with the contained oocyte. They support the oocyte through the provision of nutrients and growth factors, control its meiotic cycle and ensure it is appropriately oriented and instructed for impending ovulation. Furthermore, granulosa cells contribute to the formation of the zona pellucida and the follicular fluid, providing an optimal environment for the oocyte's growth and maturation. These cells, thus, perform multiple vital roles, underscoring their importance in fertility and reproductive health.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0000501") +AnnotationAssertion(Annotation( "DOI:10.1016/j.pharmthera.2015.05.007") Annotation( "DOI:10.1038/s41574-018-0020-6") Annotation( "DOI:10.1093/annonc/mdh216") Annotation( "https://www.sciencedirect.com/topics/neuroscience/somatostatin-cell") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Type D enteroendocrine cells, also known as D or delta cells, are specialized hormone-releasing cells found in the pancreas and also scattered throughout the lining of the gastrointestinal tract in mammals, notably within the stomach and the upper part of the small intestine known as the duodenum. The primary role of D cells is to produce and secrete somatostatin, a potent paracrine inhibitor. +In the gastrointestinal tract, somatostatin slows down digestion. It reduces gastric acid secretion and slows down the rate of gastric emptying, thereby prolonging and controling the digestive p. Functionally, these effects are aimed at sustaining nutrient absorption to optimize energy extraction from consumed food. +In the pancreas, D cells maintain a vital role in endocrine regulation. D cells in the pancreatic islands secrete somatostatin to inhibit the release of both insulin and glucagon from type A cells and B cells, glucoregulatory hormones that control blood sugar levels. Hence, D cells contribute considerably to the homeostasis of the body's metabolic processes. It is also noteworthy that dysfunctional D cells or irregular somatostatin signaling has been associated with certain pathologies such as neuroendocrine tumors and gastric ulcers.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0000502") +AnnotationAssertion(Annotation( "DOI:10.1007/s00018-002-8412-z") Annotation( "DOI:10.1038/nature09637") Annotation( "DOI:10.1038/nrmicro2546") Annotation( "DOI:10.1146/annurev-physiol-030212-183744") Annotation( "DOI:10.3389/fimmu.2020.00587") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Paneth cells are specialized epithelial cells that are primarily located at the bottom of the crypts of Lieberkühn in the small intestine, where they play a pivotal role in maintaining gut homeostasis. They have also been found in smaller numbers in the colonic crypts and other parts of the gastrointestinal tract. Paneth cells are characterized by large acidophilic granules, which take up most of the cytoplasmic volume, causing the nucleus to be pushed toward the base of the cell. +Paneth cells function as a part of the innate immune system. The large granules inside the cells are filled with antimicrobial peptides, such as defensins and lysozymes. Upon bacterial intrusion or cellular signaling indicating a potential infection, Paneth cells release the granules containing the antimicrobial substances into the crypt lumen, effectively serving as the first line of defense against bacterial invasion within the gastrointestinal tract. In essence, Paneth cells serve as guardians, protecting the intestinal stem cells from harmful pathogens that may disturb the gut ecosystem. +In addition to their primary role in immunity, Paneth cells are also crucial for supporting the stem cell niche in the intestinal crypts. They are located adjacent to Lgr5+ stem cells and secrete various growth factors such as EGF, TGF-alpha, Wnt3, and Notch ligand Dll4. These factors regulate the self-renewal and differentiation of these stem cells, which continuously replenish the intestinal epithelium. Consequently, any abnormality or dysfunction in Paneth cells could lead to a disturbance in gut homeostasis, possibly resulting in various illnesses such as inflammatory bowel disease.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0000510") +AnnotationAssertion(Annotation( "DOI:10.1007/BF00710764") Annotation( "DOI:10.1038/nrgastro.2013.36") Annotation( "DOI:10.1097/MOG.0b013e32832ebfac") Annotation( "DOI:10.1111/prd.12116") Annotation( "DOI:10.1152/physrev.00011.2011") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Acinar cells are specialized exocrine gland cells that secrete specific enzymes and fluids to aid in digestion. Found primarily in the pancreas and salivary glands, the term acinar is derived from the Latin word 'acinus' which means 'grape'; this is because acinar cells are arranged in a grape-like cluster around small ducts, formulating an acinus structure. +In the salivary glands, acinar cells secrete digestive enzymes as well as other substances such as mucus and water. These secretions service the initial stages of the digestive process, preparing the consumed food for onward digestion in the stomach and intestines by lubricating and partially breaking it down. +In the pancreas, acinar cells are responsible for synthesizing and secreting a significant amount of digestive enzymes, such as trypsin, chymotrypsin, and amylase. These enzymes are stored in zymogen granules inside the acinar cells until they are dispatched into the small intestine. Once within the small intestine, they break down proteins, carbohydrates, and fats into substances that can be absorbed. This is vital to the effective and efficient digestion and absorption of nutrients from the food we consume. +Acinar cells have high protein synthesis rates and are susceptible to accumulation of misfolded proteins; the subsequential induction of ER stress is thought to be involved in the development of pancreatitis, a serious inflammatory disease of the exocrine pancreas.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0000622") +AnnotationAssertion(Annotation( "DOI:10.1038/s41467-022-33748-1") Annotation( "DOI:10.1038/s41572-020-0196-7") Annotation( "DOI:10.1146/annurev-physiol-020911-153238") Annotation( "DOI:10.1159/000481633") Annotation( "DOI:10.3389/fcell.2021.771931") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Podocytes are highly specialized, terminally differentiated glomerular visceral epithelial cells that wrap around the capillaries in the kidneys. They play an essential role in kidney function, particularly in the filtration selectivity of the glomerulus. Each podocyte is characterized by a unique architecture with a large cell body, ‘major processes’ extending outwardly from the cell body and ‘foot processes’, also known as pedicels, which surround. the glomerular capillary loops +Podocytes represent the last barrier of the glomerular filtration membrane in the kidney. This barrier prevents the leakage of plasma proteins from the blood into the urine, hence maintaining protein homeostasis in the body. The foot processes of the podocytes interdigitate with those from neighboring cells. The cell-cell junctions between the foot processes, the slit-diaphragms, are thought to create a molecular sensor of renal filtration that prevents the passage of macromolecules while allowing water and small solutes to pass. +Podocytes also contribute to the glomerular basement membrane by secreting collagen and maintain glomerular endothelial cell fenestration by secreting VEGFA. They have been shown to play a role in inducing cytoskeletal regulation, cell adhesion, and inflammatory response, consistent with their essential function in the kidney. +The importance of podocytes is further emphasized by the effects of their damage or loss. Abnormalities in podocytes often result in severe kidney diseases (podocytopathies), including focal segmental glomerulosclerosis (FSGS) and minimal change disease (MCD). Injury to the podocytes can result in \"effacement\" or flattening of foot processes, leading to increased permeability of the filtration barrier and proteinuria (an excess of serum protein in urine) which is a common symptom of kidney diseases.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0000653") +AnnotationAssertion(Annotation( "DOI:10.1002/ar.1092200109") Annotation( "DOI:10.1016/0306-4522(86)90162-4") Annotation( "DOI:10.1016/j.devcel.2012.11.003") Annotation( "DOI:10.1038/s41467-022-31571-2") Annotation( "DOI:10.1152/ajprenal.90601.2008") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Fenestrated cells are specialized epithelial cells that are characterized by a distinctive structural feature, fenestrations or tiny pores, which allow an exchange of substances such as fluids, nutrients, and waste between blood vessels and the surrounding tissue environments. These cells are present in various types of epithelial tissues in the human body, including the intestinal tract, endocrine glands, and certain parts of the renal system. +There are multiple types of endothelial cell fenestrations. The most common type is found in systemic capillaries of the endocrine tissue (e.g., pancreatic islets), gastrointestinal mucosa, and renal peritubular capillaries. Here, the fenestrated cells have fenestrations in their peripheral cytoplasm with a unique thin and permeable diaphragm that provides a high degree of selectivity, blocking the passage of larger molecules while allowing the free movement of smaller ones. In contrast, other types of fenestrations, such as the discontinuous epithelium of the liver sinusoidal endothelial cells, do not have diaphragms. +Characteristically, fenestrated cells play a vital role in the filtering process of body systems. They are a key part of the glomeruli in the kidneys where blood is filtered under high pressure. The fenestrations present in the endothelial cells lining the capillaries of the glomerulus allow the free passage of water and small solute molecules towards the Bowman's capsule, leaving behind larger proteins and cells in the blood, thereby aiding in the filtration and waste removal process. +In the endocrine system, fenestrated cells in glandular capillaries allow the prompt release of hormones into the bloodstream. These cells have tightly clustered fenestrations which increase the surface area available for passive diffusion, improving the efficiency of hormone secretion. In villi of the small intestine, these cells increase absorption efficiency, permitting the exchange of water, electrolytes, and nutrients. +Overall, fenestrated cells contribute immensely to important physiological processes of filtration, absorption, and secretion, primarily connecting our body's circulation system with the surrounding tissues and organs.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0000666") +AnnotationAssertion(Annotation( "DOI:10.1038/nature08529") Annotation( "DOI:10.1093/jb/mvv121") Annotation( "DOI:10.1136/gut.47.5.735") Annotation( "https://www.ncbi.nlm.nih.gov/books/NBK534232/") Annotation( "https://www.sciencedirect.com/topics/medicine-and-dentistry/microfold-cell") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +M cells, or microfold cells, of the gut are specialized epithelial cells found in the lining of the gut, specifically in the follicle-associated epithelium of mucosa-associated lymphoid tissue, where they function as sentries against toxins and pathogens. M cells are characterized by apical microfolds (hence their alternate name) which express unique adhesion molecules that enable them to sample the luminal macromolecules. +Other morphological features that distinguish M cells from other intestinal mucosal cells include sparse microvilli and a reduced thickness of the glycocalyx, which permits adhesion while not hindering the transport of molecules. They also have unique intraepithelial invaginations on the basolateral side which are filled with macrophages and other immune cells that can process the engulfed macromolecules quickly. +These morphological characteristics enable M cells to serve a dual role in immune responses. They initiate the immune response by transporting antigens (such as toxic or pathogenic substances) across the epithelial layer to lymphocytes and antigen-presenting cells in the underlying lymphoid tissue. This specialized transport process is called 'transcytosis.' They also have specialized molecules like glycoprotein-2 for bacterial uptake. Simultaneously, M cells help maintain immune tolerance to food antigens and commensal bacteria, preventing unnecessary reactions to non-pathogenic substances and hypersensitivity conditions. While these functions are crucial for well-being, M cell dysfunction can lead to serious conditions like Crohn's disease and other inflammatory bowel diseases.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0000682") +AnnotationAssertion(Annotation( "DOI:10.1016/j.febslet.2014.07.005") Annotation( "DOI:10.1016/j.mce.2015.06.028") Annotation( "DOI:10.1038/s41580-020-00317-7") Annotation( "DOI:10.1210/jc.2003-030630") Annotation( "DOI:10.1369/00221554155835") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +PP cells, also known as pancreatic polypeptide cells (and previously called F cells or gamma cells), are enteroendocrine cells predominantly found in the islets of Langerhans in the head of the pancreas. They are one of the four main endocrine cell types present in the pancreatic islets, along with type A, B and D cells. PP cells are notable for their production of pancreatic polypeptide, an anorexigenic hormone that modulates food intake and energy homeostasis. +By secreting pancreatic polypeptide, PP cells play a significant role in the management of both digestive and appetite regulation. Upon ingestion of food, there is a significant increase in the secretion of pancreatic polypeptide, which then reduces biliary secretion and helps slow down the movement of food through the digestive tract. This allows more time for digestion to take place and nutrients to be absorbed, promoting the efficient use of dietary intake. The pancreatic polypeptide further reduces appetite by interacting with the hypothalamus, the area of the brain responsible for control of hunger. +Given their important role in digestion, malfunction or damage to PP cells can lead to a disturbance in the digestive process and contribute to some disease conditions. For example, an overproduction of pancreatic polypeptide can result in conditions such as pancreatic tumors and diabetes. Conversely, an under secretion might contribute to obesity due to impaired dietary control. Furthermore, PP cells may also play a role in the body's energy balance, suggesting their implication in conditions related to energy metabolism.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0000696") +AnnotationAssertion(Annotation( "DOI:10.1002/nau.22195") Annotation( "DOI:10.1038/ki.2009.73") Annotation( "DOI:10.1038/ncpuro0672") Annotation( "DOI:10.1038/s41579-020-0324-0") Annotation( "DOI:10.1152/physrev.00041.2019") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Urothelial cells are a unique type of epithelial cell found lining the urinary tract system. They form the urothelium, a specialized, multi-layered epithelium that lines major portions of the urinary tract, including the renal pelvis, ureters, bladder, and the proximal part of the urethra. The distinct characteristic of urothelial cells is their ability to stretch and contract depending on the volume of liquid they contain - a feature that facilitates the essential role they play in maintaining the functionality and integrity of the urinary system. +The primary function of urothelial cells is to provide an impermeable barrier to urine, preventing the toxic components present in the urine from seeping back into the body's bloodstream. The urothelium consists of a superficial umbrella cell layer, 1–2 layers of intermediate cells, and a basal cell layer. The umbrella layer is composed of large, mostly binucleated cells that are covered in an asymmetrical unit membrane, the uroplakin plaques. These plaques function to seal the apical membrane of the bladder from the toxic and highly variable contents of urine. The lipid bilayer structure of uroplakin plaques has an exceptionally high concentration of uroplakins that contribute to the barrier function of the urothelium. +Beyond their mechanical function, urothelial cells also play a role in sensing and signaling changes in the urinary system. They express a number of sensor molecules or respond to thermal, mechanical and chemical stimuli and can release chemical mediators. This allows them to act as sensory transducers because they detect changes in the filling state of the bladder and transmit this information to the nervous system. Moreover, these versatile cells contribute to the defense mechanism against urinary tract pathogens. They respond to bacterial infections by releasing chemical messengers, cytokines and chemokines, to attract immune cells, and also can engulf pathogens via endocytosis.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0000731") +AnnotationAssertion(Annotation( "DOI:10.1038/nri.2017.28") Annotation( "DOI:10.1111/sji.12883") Annotation( "DOI:10.1182/blood-2009-07-235028") Annotation( "DOI:10.3389/fimmu.2015.00423/full") Annotation( "DOI:10.3389/fimmu.2019.02035") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Classical monocytes are a subtype of monocytes that are characterized by high CD14 but no CD16 expression. Emerging from the bone marrow and entering the bloodstream, these cells play central roles in immune responses and regulation of inflammation. CD14-positive CD16-negative monocytes form the majority of circulating monocytes in the body, typically contributing to around 80-90% of the total monocyte pool. +The primary function of the classical monocytes is to serve in the frontline of host defense against infections. They are primed to migrate to sites of infection, and they express pattern recognition receptors that help them identify and phagocytose pathogens, leading to their destruction. Classical monocytes also contribute to inflammation by producing several pro-inflammatory cytokines including interleukins and tumor necrosis factors. +In response to specific signals from tissues under pathological conditions, such as infection or injury, classical monocytes can leave the bloodstream and migrate towards the affected sites. Following their arrival, these cells differentiate into diverse cell types including macrophages and dendritic cells to combat specific pathogens or injury. Dysregulated monocyte activity can lead to the development of many human diseases including inflammation, infection, tissue injury, and various autoimmune diseases.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0000860") +AnnotationAssertion(Annotation( "DOI:10.1038/s41392-023-01452-1") Annotation( "DOI:10.1186/s12935-021-02089-2") Annotation( "DOI:10.3389/fimmu.2015.00263") Annotation( "DOI:10.3389/fimmu.2020.583084") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Inflammatory macrophages, also sometimes referred to as M1 or classically activated macrophages, play an important role in the inflammatory response. The M1/M2 classification is based upon macrophage polarization rather than macrophage location and refers to macrophage activation towards either a more inflammatory or more resolving phenotype, respectively, although the functional diversity of macrophages is more nuanced than such a dichotomy suggests. +Inflammatory macrophages are derived from monocytes recruited to a site of infection or injury. M1 macrophages are classically activated, typically by IFN-γ or lipopolysaccharide (LPS). Upon sensing signs of inflammation, they quickly respond by increasing their pro-inflammatory activity. They achieve this by producing a range of signaling molecules, such as nitric oxide, reactive oxygen species, and numerous cytokines such as tumor necrosis factor-alpha (TNF-alpha) and interleukin-1, -6 and -12. The release of these potent molecules helps to recruit other immune cells to the site, killing off pathogenic organisms and facilitation inflammation. At the same time, M1 macrophages can also present antigens to T cells, thereby helping to induce an adaptive immune response. Over time, these macrophages may transition in phenotype and function to help resolve the inflammation and promote tissue repair. +Despite the beneficial role of inflammatory macrophages in dealing with pathogens, chronic activation of these cells can lead to harmful effects. Over time, continuous production of pro-inflammatory molecules can cause damage to tissues and organs. This is seen in certain chronic inflammatory diseases, such as atherosclerosis, diabetes, obesity, asthma, and various autoimmune disorders. In such situations, the normally protective function of inflammatory macrophages is not properly controlled, which can contribute to disease pathology.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0000863") +AnnotationAssertion(Annotation( "DOI:10.1038/s41392-023-01452-1") Annotation( "DOI:10.1186/s12935-021-02089-2") Annotation( "DOI:10.3389/fimmu.2015.00263") Annotation( "DOI:10.3389/fimmu.2020.583084") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Alternatively activated macrophages, also referred to as M2 macrophages, are immune cells originating from monocytes. The M1/M2 classification is based upon macrophage polarization rather than macrophage location and refers to macrophage activation towards either a more inflammatory or more resolving phenotype, respectively, although the functional diversity of macrophages is more nuanced than such a dichotomy suggests. +M2 macrophages cells are differentiated from their precursors generally in response to Th2 cytokines, such as interleukin-4 (IL-4), interleukin-10 (IL-10), and interleukin-13 (IL-13). Tissue-resident macrophages are also sometimes said to have an “M2-like” phenotype. M2 macrophages play key roles in immunoregulation and disease resolution. +Functionally, alternatively activated macrophages are essential in wound healing and tissue repair and remodeling, largely due to their potent anti-inflammatory actions and their ability to promote angiogenesis. They achieve these functions by the production of specific growth factors and signaling proteins including Arg1, Ym1/2, Fizz1, and TGF-β. Additionally, they provide defense against specific categories of pathogens, particularly parasites, through specific communication with Th2 cells. +However, dysfunction of M2 macrophages can be harmful. Alternatively activated macrophages have been associated with several pathological conditions such as asthma, fibrosis, and tumor progression. This is due to their capacity to inhibit inflammatory responses, promote unneeded wound healing processes, and support tumour growth and spreading. Furthermore, complex roles have been observed in metabolic disorders, cardiovascular diseases, and neurodegenerative diseases, showing the diverse functional spectrum of these cells.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0000890") +AnnotationAssertion(Annotation( "DOI:10.1016/0165-6147(89)90192-2") Annotation( "DOI:10.1038/nrgastro.2013.36") Annotation( "DOI:10.1097/01.mog.0000239863.96833.c0") Annotation( "https://www.ncbi.nlm.nih.gov/books/NBK54134/") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Pancreatic acinar cells are the functional units of the exocrine pancreas. These cells are structurally arranged in small clusters - or acini - with a small central lumen, and their primary function is to produce and secrete enzymes that facilitate digestion of proteins, carbohydrates, and fats within the small intestine. +Some of the most important digestive enzymes synthesized by the pancreatic acinar cells include amylase, which digests carbohydrates, lipase, which breaks down fats, and several proteases such as trypsin and chymotrypsin which are vital for the digestion of proteins. Importantly, these enzymes are produced as proenzymes or zymogens to avoid autolysis, or the breakdown of the pancreas itself. +The release of these enzymes by the pancreatic acinar cells is strictly regulated by hormones and neurochemicals. Cholecystokinin (CCK) released from the enteroendocrine cells in the duodenum cause the release of these enzymes. Moreover, acinar cells also respond to another hormone, secretin, by releasing bicarbonate-rich fluid which helps to neutralize the gastric acid in the duodenum. +Dysregulation in the function of pancreatic acinar cells can lead to severe health issues, including pancreatitis, which is characterized by inflammatory damage to the organ due to the premature activation of digestive enzymes.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0002064") +AnnotationAssertion(Annotation( "DOI:10.1016/j.diabres.2018.06.013") Annotation( "DOI:10.1210/en.2016-1748") Annotation( "DOI:10.2337/db15-1541") Annotation( "DOI:10.2337/dbi19-0002") Annotation( "DOI:10.3389/fphys.2012.00349/full") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Type A enteroendocrine cells, also known as alpha cells or A cells, are a species of endocrine cells primarily located in the pancreatic islets of Langerhans; they have also been identified within the lining of the stomach. Functionally, these cells are pivotal in glucose metabolism and homeostasis, accounting for about 20% of the total population of cells in the pancreatic islets. +The primary role of type A enteroendocrine cells involves the synthesis, storage, and secretion of the peptide hormone glucagon, which is critical in energy regulation throughout the body. In response to a decrease in blood glucose levels, the pancreatic A cells are stimulated to secrete glucagon into the bloodstream. Glucagon acts on its target cells, mainly in the liver, to stimulate glycogenolysis and gluconeogenesis processes, thereby increasing blood glucose levels back to normal. In this way, pancreatic A cells play an integral role in maintaining glucose homeostasis and preventing hypoglycemia. +Pancreatic A cells also participate in the local regulation of islet activities as glucagon acts through glucagon receptors on A, B and D type cells within the islets. Recent studies have also shown that Pancreatic A cells play a role in the generation and regeneration of B type cells. Following beta cell injuries pancreatic A cells increase in numbers and produce Glucagon-like peptide-1 (GLP-1), which increases the proliferation and cytoprotection of beta cells. In response to extreme injury of B type cells pancreatic A cells can transform (transdifferentiate) into functioning B type cells. +Until recently, glucagon has been considered a pancreas-specific hormone; however, extrapancreatic glucagon has been reported in patients who had undergone complete, and glucagon-positive cells been identified in the human stomach, indicating that Type A enteroendocrine cells are not restricted to the pancreas.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0002067") +AnnotationAssertion(Annotation( "DOI:10.1101/cshperspect.a028241") Annotation( "DOI:10.1146/annurev-physiol-021014-071931") Annotation( "DOI:10.1152/ajplung.00329.2019") Annotation( "DOI:10.1159/000196486") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Ciliated columnar cells of the tracheobronchial tree compose the inner lining of the tracheobronchial tree, the system of airways consisting of trachea, bronchi and bronchioles that allow passage of air into the lungs, where gas exchange occurs. A defining feature of these endo-epithelial cells are the tiny hair-like structures covering their surface, known as cilia. The nucleus is located at the base of the cell, and the area above it is rich in mitochondria and well-developed endoplasmic reticulum, both crucial for the energy-intensive process of cilia operation. +The primary function of these ciliated cells is to keep the respiratory tract clean via mucociliary clearance or the respiratory escalator. These cells create a two-layered 'coat': The lower \"sol\" layer is watery where the cilia can beat in coordinated waves, and the upper \"gel\" layer is thick and sticky, trapping inhaled particles, such as dust, bacteria, viruses, and other potentially harmful substances. This rhythmical beating of the cilia then moves the mucus and trapped particles upwards and out of the respiratory tract, which is then either coughed out or swallowed. +Damage or dysfunction of these ciliated cells, as seen in diseases such as primary ciliary dyskinesia, cystic fibrosis, or chronic bronchitis, may lead to reduced or ineffective mucociliary clearance and an increased susceptibility to respiratory infections.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0002145") +AnnotationAssertion(Annotation( "DOI:10.1007/978-3-211-99390-3_83") Annotation( "DOI:10.1038/nature16161") Annotation( "DOI:10.1111/j.1469-7580.2005.00403.x") Annotation( "DOI:10.3389/fphys.2015.00087") Annotation( "DOI:10.5114/ceji.2022.124416") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Brush cells, also referred to as tuft cells or multivesicular cells, are a specialized type of epithelial cell mainly noted for their characteristic 'brush border' composed of microvilli. These cells reside in the epithelial lining of tissue organs such as the respiratory tract, gastrointestinal tract, and the bile ducts. The name derives from their distinct appearance under the microscope, which resembles a brush due to the dense layer of microvilli protruding into the lumen. +A key function of brush cells is chemosensation: They express a variety of signaling molecules and receptors that enable them to detect specific chemical stimuli in the environment and act as sensory transducers. Many of these receptors are responsive to luminal content, which makes brush cells vital for regulating and coordinating appropriate physiological responses to changes in these substances. +Recent research has also elucidated an important role for these cells in immunity. Intestinal brush cells have been found to be the source of a cytokine called interleukin-25, which can initiate type 2 immune responses during parasitic infections. This immune function, along with the chemosensing abilities, signifies that brush cells could serve crucial roles in health and disease, although much research is still required to fully elucidate their myriad roles in physiology and pathology. Overall, brush cells are a versatile cell type, whose distinct morphology and functional capabilities allow them to perform a unique set of functions within the body.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0002204") +AnnotationAssertion(Annotation( "DOI:10.1016/B978-1-4377-1926-0.10005-0") Annotation( "DOI:10.1016/j.biocel.2007.10.034") Annotation( "DOI:10.1098/rstb.2010.0324") Annotation( "DOI:10.1136/bmjophth-2020-000459") Annotation( "https://www.sciencedirect.com/topics/immunology-and-microbiology/lens-fiber") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Secondary lens fibers are a specialized type of elongated cells located within the structure of the eye's lens. They play an essential role in vision by enabling light transmission and focus on the retina, which allows for clear, distinct vision. These cells are characterized by their lack of nuclei and organelles, their orderly alignment, and their high protein content, particularly crystallins. +Lens fibers are differentiated from equatorial epithelial cells of the lens in a process that involves cell elongation, denucleation and tight packing, which serve to reduce light scattering occurrences in the eye. This differentiation accelerates substantially after birth in comparison to during embryogenesis and continues throughout life, contributing to the growth of the eye lens. Secondary lens fibers are specifically those cells that are newly differentiated and cover the old lens fiber core. This process also leads to the removal of light-obstructing cellular components, mainly nuclei and organelles, making these fibers transparent and ideal for their function. +The fibers carry out their primary function of light refraction via a high concentration of specialized proteins known as crystallins, which form a gradient of refractive index together with the cytoplasm. This index manipulation facilitates precise light focus onto the retina. Secondary lens fibers also contribute to the lens's shape and biomechanical properties through intercellular interactions, particularly at the sutures where the ends of the fibers meet. Any disruption to secondary lens fibers can lead to vision problems, including cataracts, which is the clouding of the lens resulting from the aggregation of crystallin proteins.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0002225") +AnnotationAssertion(Annotation( "DOI:10.1016/j.cell.2013.07.004") Annotation( "DOI:10.1038/s41575-018-0081-y") Annotation( "DOI:10.1038/s41580-020-0278-0") Annotation( "DOI:10.1101/gad.1674008") Annotation( "DOI:10.1111/j.1365-2184.2009.00642.x") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Intestinal crypt stem cells, also known as crypt base columnar cells, are a unique type of cell, characterized by the highly specific marker LGR5, found in the intestinal epithelium. Situated at the bottom of the minute pockets known as crypts of Lieberkühn, these are undifferentiated cells that have the ability to perpetually self-renew, as well as differentiate into various other cell types that constitute the epithelial lining of the intestine. +The fundamental role of intestinal crypt stem cells is to provide a constant supply of new cells to maintain the cellular turnover of the intestinal epithelium, a tissue known for rapid self-renewal. These stem cells are nurtured and protected by specialized epithelial and mesenchymal cells, and together constitute the intestinal stem cell niche. +An important function of intestinal crypt stem cells is to sustain the balance between cell division and programmed cell death, called apoptosis, to ensure the integrity of the intestinal lining. Given their active proliferation rate, these stem cells initiate the creation of diverse differentiated cell types, including enterocytes (the primary absorptive cells in the intestinal lumen), goblet cells (that produce mucus to protect the epithelial layer), enteroendocrine cells (involved in producing gastrointestinal hormones), and Paneth cells (involved in secreting antimicrobial peptides). This diversity in output regulates the physiological activities of the gut ranging from nutrient absorption, hormone secretion, bacterial balance, to immunity. +Research studies suggest that dysregulation in intestinal crypt stem cell proliferation and differentiation is associated with several intestinal disorders including intestinal cancer, and various enteropathies.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0002250") +AnnotationAssertion(Annotation( "DOI:10.1016/B978-0-12-819402-7.00001-2") Annotation( "DOI:10.1016/B978-012369442-3/50154-9") Annotation( "DOI:10.1016/j.mce.2015.06.028") Annotation( "DOI:10.1038/s42255-019-0148-2") Annotation( "DOI:10.3389/fendo.2023.1192311") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Pancreatic polypeptide (PP) cells (also called F or gamma cells) are unique endocrine cells located within the Islets of Langerhans in the pancreas. PP cells are one of the rarer pancreatic cell types and are more prevalent in the head and neck of the pancreas. They are critical in normal pancreatic physiological functions and are involved in the development of pancreatic endocrine disorders. +The primary function of PP cells is the production and secretion of the pancreatic polypeptide hormone (PP). This hormone plays a crucial role in several gastrointestinal functions and metabolic responses. The release of the PP hormone is stimulated after eating, especially in protein-rich meals, leading to it being present in large amounts during digestion. The fundamental role of PP is to self-regulate pancreatic secretion activities ensuring its exocrine and endocrine functions are under control. +The pancreatic polypeptide hormone from PP cells also aids in adapting to low physical activity and fasting by reducing the production of insulin and glucagon and inhibiting the hepatic glucose production. Additionally, this hormone influences gut motility by slowing down the gastric emptying and reducing small intestinal transit, thereby controlling the pace at which nutritional substances are absorbed. Because of these functions, any malfunction or irregularity in PP cells can result in various disorders such as diabetes and pancreatic diseases.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0002275") +AnnotationAssertion(Annotation( "DOI:10.1016/S1569-2590(05)10005-6") Annotation( "DOI:10.1111/j.1444-0938.2002.tb02384.x") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Pigmented ciliary epithelial cells, which are a type of pigment cell, have a crucial function within the eye's ciliary body. The ciliary body, located behind the iris, is one of the eye’s most vital structures and consists of two types of epithelial cells: the pigmented and the non-pigmented ciliary epithelial cells. The pigmented ciliary epithelial cells form the outer layer of the ciliary body and exhibit a black or brown pigmentation due to the melanin they contain. +One key function of pigmented ciliary epithelial cells is to aid in the formation of aqueous humor, an intraocular fluid that nourishes the cornea and lens, and maintains intraocular pressure which is essential for the eye’s shape and light refraction. These cells facilitate this function in conjunction with the non-pigmented ciliary epithelial cells. Together, the pigmented and non-pigmented ciliary epithelial cells form a bilayer epithelium that allows the secretion of aqueous humor through a bi-directional fluid transport mechanism. +Pigmented ciliary epithelial cells also contribute to the blood-aqueous barrier, a physiological frontier that controls the entry and exit of various substances from the blood to the aqueous humor and vice versa. The pigmentation in these cells, intensified by melanin, helps to absorb scattered light coming into the eye, reducing any potential damage and glare.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0002303") +AnnotationAssertion(Annotation( "DOI:10.1165/rcmb.2013-0049OC") Annotation( "DOI:10.1186/s12931-014-0160-8") Annotation( "DOI:10.2353/ajpath.2010.090870") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +The basal epithelial cells of the tracheobronchial tree are critical components found in the lining of the airway passages, including the trachea and bronchi. They are keratin-5-positive, nonciliated, cuboidal cells and typically tightly attached to the basement membrane. In humans, the proportion of basal cells in the respiratory epithelium gradually decreases going down the tracheobronchial tree: they represent approximately 34% of the cells in the trachea, 27% in the large airways, and 10% in the small airways, although it is worth noting that there are differences in the compositions of the tracheobronchial epithelia between different species. +Basal epithelial cells serve as the basal layer of the tracheobronchial epithelium, providing both structural and regenerative support for the epithelial tissue that lines the upper regions of the respiratory tract. They serve as progenitor or stem cells that are capable of differentiating into multiple cell types, such as ciliated and secretory cells. This gives them a central role in homeostatic maintenance of the epithelium, and in repairing damaged epithelium after an injury or during disease. This regenerative capacity is crucial in maintaining the integrity of the tracheobronchial surface, especially given its continual exposure to inhaled irritants and microorganisms. +In addition to their primary restorative function, basal epithelial cells are also involved in the initial immune response within the tracheobronchial tree. Equipped with pattern recognition receptors, these cells can identify and respond to pathogenic organisms, triggering an immune response and producing a range of inflammatory mediators, such as cytokines and chemokines, to help combat infections.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0002329") +AnnotationAssertion(Annotation( "DOI:10.1016/S1357-2725(02)00083-3") Annotation( "DOI:10.1111/febs.15731") Annotation( "DOI:10.1165/ajrcmb.25.5.f218") Annotation( "DOI:10.2147/COPD.S38938") Annotation( "DOI:10.3109/01902148.2013.791733") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +The respiratory goblet cell is a highly specialized cell type found primarily within the respiratory tract, including the nose, trachea, and lungs. Named because their shape resembles a goblet - a drinking vessel with a wide body and narrow neck - these cells form a vital part of the respiratory system's protective mechanisms. They are found within the columnar epithelium lining these organs, which forms a barrier between the internal body and the exterior environment. +A principal function of the respiratory goblet cell is the production and secretion of mucus, a carbohydrate-rich, viscous and gel-like substance that plays a critical role in trapping dust, bacteria, viruses, and other airborne particles that are inhaled. The mucus secreted by the goblet cells covers the lining of the respiratory tract, effectively catching these particles and preventing them from reaching the lungs and causing infection. Mucus also provides hydration and lubrication to the respiratory tract surfaces, which is important in maintaining the tissue's health and functioning. +In addition to their mucus-secreting capabilities, respiratory goblet cells also play a significant role in the body's inflammatory responses. When the respiratory system is exposed to irritants or pathogens, the number and activity of goblet cells often increase, leading to a higher production of mucus. This is a protective response designed to trap and neutralize the harmful substances more effectively. However, in conditions like chronic obstructive pulmonary disease (COPD) and asthma, an overproliferation of goblet cells, also known as goblet cell hyperplasia, can lead to excessive mucus production and airway obstruction.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0002370") +AnnotationAssertion(Annotation( "DOI:10.1002/hep.31252") Annotation( "DOI:10.1016/j.ajpath.2023.02.012") Annotation( "DOI:10.1016/j.biocel.2010.06.020") Annotation( "DOI:10.1016/j.gastha.2022.07.015") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Intrahepatic cholangiocytes represent a subset of the biliary epithelial cells that form a network of tubes in the liver called the biliary tree The intrahepatic cholangiocytes reside specifically in the intrahepatic bile ducts and play a crucial role in liver physiology and bile production and secretion, thereby aiding in the digestion and absorption of fats in the small intestine. These specific cholangiocytes arise from bipotent hepatoblasts, whereas extrahepatic cholangiocytes share an embryologic origin with the ventral pancreas. +Recent research suggests that there is also heterogeneity within populations of intrahepatic cholangiocytes with different transcriptional profiles, proliferative capacity, and biological function; for example, subpopulations differ in calcium-mobilizing receptors. +The primary function of intrahepatic cholangiocytes is related to bile formation and maintenance of its flow. In addition to their secretory and absorptive activities, they are involved in the regulation of bile composition, volume, and alkalinization, contributing to the neutralization of the acidic chyme (partly digested food) that enters the intestine from the stomach. Intrahepatic cholangiocytes are also recognized for their role in liver regeneration and repair, often proliferating in response to injury. +Intrahepatic cholangiocytes take part in certain pathological conditions, like primary biliary cirrhosis and cholangiocarcinoma. Changes in these cells often lead to abnormalities in bile formation and transport, causing cholestatic liver diseases. Overall, the primary and secondary functional activities of intrahepatic cholangiocytes are vital in maintaining liver function, digestive processes, and contributing to the body's response to liver injury.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0002538") +AnnotationAssertion(Annotation( "DOI:10.1007/s00441-008-0706-5") Annotation( "DOI:10.1038/s41569-022-00770-1") Annotation( "DOI:10.1038/s41598-021-01360-w") Annotation( "DOI:10.3390/ijms20184411") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Vein endothelial cells form a thin layer of squamous cells, the endothelium, lining the interior surface of veins throughout the body. They shape the inner cellular lining of the entire vascular system, including the heart, playing a crucial role in blood circulation. The unique characteristic compact arrangement of these cells enables veins to act as a barrier between the blood (that can contain foreign substances) and the surrounding venous tissue and maintain the integrity of the vascular system. +The primary function of vein endothelial cells is to control the exchange of substances between the bloodstream and the surrounding tissues. They facilitate selective transportation of molecules depending on their size and solubility, including gases, nutrients, hormones, and waste products. Vein endothelial cells also play a protective role by inhibiting the translocation of toxins or pathogens from blood to tissues. Additionally, these cells are involved in blood coagulation and inflammation response, primarily by producing substances that inhibit blood clot formation under normal conditions and initiating clotting when necessary. +Another significant function of vein endothelial cells is the regulation of blood flow and blood pressure. They produce and release several substances, including nitric oxide and prostacyclin, which help in controlling vasodilation and vasoconstriction, thereby regulating blood pressure. These cells are also responsible for angiogenesis, the formation of new blood vessels, which is crucial during wound healing and in the formation of granulation tissue. Consequently, any dysfunction in vein endothelial cells can lead to severe health problems like atherosclerosis, hypertension, and thrombosis.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0002543") +AnnotationAssertion(Annotation( "DOI:10.1016/j.biopha.2019.108765") Annotation( "DOI:10.1016/j.tibtech.2006.01.010") Annotation( "DOI:10.1038/s41536-019-0083-6") Annotation( "DOI:10.1096/fj.202100332R") Annotation( "DOI:10.1111/dgd.12049") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Mesenchymal stem cells of adipose tissue, also known commonly as adipose-derived stem cells (ADSCs), are a population of adult stem cells that can be obtained easily from adipose tissues. They have many of the same regenerative properties as other mesenchymal stem cells, but are more easily accessible than bone marrow-derived stem cells. +Adipose-derived stem cells show immense promise in the field of regenerative medicine due to their ability to differentiate into adipocytes, chondrocytes, myocytes, osteoblasts, and other cell types. ADSCs also possess immunomodulatory and homeostatic functions: they have the ability to suppress immune responses and provide a therapeutic environment for tissue repair and regeneration, as well as supporting the proliferation of adipocytes and the overall expansion of adipose tissue and contributing to the tissue's ability to react to demands of energy storage and mobilization. Dysfunction of these cells may contribute to metabolic complications observed in obesity and diabetes. +ADSCs have been used for therapeutic applications such as pathological wound healing, severe refractory acute graft-versus-host disease, and idiopathic thrombocytopenic purpura.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0002570") +AnnotationAssertion(Annotation( "DOI:10.1002/glia.23892") Annotation( "DOI:10.1016/B978-0-444-52902-2.00005-9") Annotation( "DOI:10.1016/j.biocel.2006.05.007") Annotation( "DOI:10.1186/1742-2094-8-110") Annotation( "DOI:10.1186/s13064-020-00140-y") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Schwann cells, also known as neurolemmocytes, are a type of glial cell located in the peripheral nervous system. These cells play a significant role in the healthy functioning of nerves by producing myelin, a fatty substance that forms a coating around nerve fibers. Myelin serves as an insulator and enhances the speed and efficiency of electrical nerve impulses; a single Schwann cell can myelinate a single axon. Myelination starts by the elongation and envelopment of the Schwann cell around the axon, followed by the synthesis and deposition of myelin layers. Some studies suggest that Schwann cells may regulate neuronal action potential, muscular contraction, and the sensitive response. +While Schwann cells are most commonly known for the formation of the myelin sheath, some Schwann cells do not form myelin: Remak Schwann cells, a class of nonmyelinating Schwann cells, ensheath axons with smaller diameter, such as C fiber nociceptors in sciatic nerves and form Remak bundles. +Schwann cells are found along both motor and sensory neurons and are crucial for the advancement and recovery of peripheral nerve injuries, due to their capacity to support nerve regeneration. In cases of nerve injury, Schwann cells play a vital role in recovery by initiating Wallerian degeneration, a process in which the part of the axon distal to the injury site degrades and is then cleared away. Following this, Schwann cells can guide the regrowth of the nerve, providing a conducive environment for axon regeneration. They remodel themselves into a regenerative phenotype, proliferate, and organize themselves into bands of Büngner that provide physical and chemical guidance for the regrowths of axons. This function of Schwann cells in the repair and regeneration of nervous system highlights their therapeutic potential in peripheral nerve injury treatments.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0002573") +AnnotationAssertion(Annotation( "DOI:0.1016/j.preteyeres.2015.08.001") Annotation( "DOI:10.1016/j.preteyeres.2012.08.004") Annotation( "DOI:10.1038/nature04482") Annotation( "DOI:10.5301/EJO.2010.6049") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Retinal blood vessel endothelial cells constitute the innermost lining of the blood vessels found in the retina, the light-sensitive layer of tissue at the back of the eye. The primary role of these cells revolves around their location within the retinal vascular system, forming the structure of the blood-retinal barrier, a subset of the larger blood-ocular barrier system. +The endothelial cells are particularly involved in the growth of new retinal blood vessels from pre-existing ones (angiogenesis); this is critical in managing the amount of oxygen and essential nutrients delivered to the ocular tissues. They are crucial for maintaining homeostasis in the retinal environment by controlling the exchange of molecules between the blood and the retina. Furthermore, they mediate immune cell trafficking, supporting the immune privilege of the eye by preventing the unrestricted infiltration of inflammatory cells into the retina, thus maintaining ocular health and normal vision. +The malfunction or dysfunction of retinal blood vessel endothelial cells is implicated in numerous ocular pathologies, particularly diabetic retinopathy, which is one of the leading causes of blindness worldwide. In such conditions, the compromise in the integrity of the blood-retinal barrier and excess angiogenesis can lead to retinal edema and pathological neovascularization, resulting in vision loss.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0002585") +AnnotationAssertion(Annotation( "DOI:10.1111/febs.16018") Annotation( "DOI:10.1152/physrev.00021.2004") Annotation( "DOI:10.3389/fphar.2021.727870/full") Annotation( "https://www.sciencedirect.com/topics/chemistry/retinal-pigment") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Retinal pigment epithelial (RPE) cells form a single layer of cells at the back of the eye sandwiched between the neurosensory retina and the choroid, playing a significant role in maintaining vision health. These pigment-laden cells are highly specialized and perform an array of metabolic and transport functions essential for the maintenance of the photoreceptor cells (rods and cones) in the retina. The pigmentation of RPE cells actively aids in the absorption of excess light and the prevention of light scattering, thus enhancing the eye's optical properties. +The retinal pigment epithelium forms a key part of the blood/retina barrier. The cells have long sheet-like microvilli on their apical membrane that project into the light-sensitive outer segments of the photoreceptors, forming a close structural interaction. The basolateral membrane of the RPE interacts with the underlying Bruch’s membrane, which separates the RPE cells from fenestrated endothelium of the choriocapillaris. +RPE cells support the photoreceptor by providing them with oxygen and nutrients (such as glucose, retinol and fatty acids) and removing waste products. They also recycle the visual pigment, in a process called the \"visual cycle\", where the RPE cells play a vital role in the regeneration of visual pigment (11-cis retinol) following the absorption of light. This is essential for the maintenance of photoreceptor excitability. +Beyond this, RPE cells take part in the phagocytosis process, where they digest the shed ends of photoreceptor outer segments, thus, preventing the build-up of waste residue that could otherwise harm retinal health. They also secrete various factors, including growth factors required to maintain the structural integrity of choriocapillaris endothelium and photoreceptors, as well as immunosuppressive factors that play an important role in establishing the immune privilege of the eye.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0002586") +AnnotationAssertion(Annotation( "DOI:10.1002/cyto.a.20952") Annotation( "DOI:10.1007/s12015-006-0015-x") Annotation( "DOI:10.1172/JCI107470") Annotation( "DOI:10.3390/app10030938") Annotation( "https://www.ncbi.nlm.nih.gov/books/NBK53254/") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Endothelial cells of the umbilical vein form the inner lining of the veins found in the umbilical cord. They are involved in tube formation and migration which are essential for angiogenesis, the process of generating new blood vessels; this is critical during the fetal stage for the development of the circulatory system. Endothelial cells of the umbilical vein also play a role in controlling the passage of white blood cells into tissues during inflammatory responses. +Because human umbilical vein endothelial cells (HUVECs) can easily be derived from the umbilical cord, and because they express common endothelial cell markers, they have been used as an epithelial cell model for studies on cell proliferation, migration, angiogenesis, and inflammation. They have been used as models for vascular diseases like atherosclerosis, for investigating how tumor cells infiltrate blood vessels and form metastases. +Thus, while endothelial cells of the umbilical vein play a critical role in vascular biology, they also represent a powerful tool in disease studies and potential treatment strategies.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0002618") +AnnotationAssertion(Annotation( "DOI:10.1186/s12931-022-02042-5") Annotation( "DOI:10.3389/falgy.2021.787128") Annotation( "DOI:110.1038/s41385-020-00370-7") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Respiratory basal cells are highly specialized cells that serve a crucial role in the human airway epithelium, predominantly found lining the surfaces of the trachea and bronchi. These cells exhibit a distinctive columnar shape and are attached directly to the basal lamina. They are characterized by the presence of high amounts of cytoplasmic keratins, predominantly keratin 5 and 14, and transcription factor tumor protein (tp63), which set them apart from other types of lung epithelial cells such as ciliated cells and secretory cells. +Basal cells are essential for maintaining airway integrity. They make up one third of all respiratory epithelial cells and serve as stem cells as they can transform into different cell types, like goblet cells, ciliated cells, and club cells, when needed for homeostatic maintenance of the epithelial barrier or to repair and restore a healthy cellular environment after injury. +Their position at the interface between the internal environment and the external atmosphere makes these cells a first line of defense against air-borne irritants, allergens, and pathogens. Their robust, intrinsic reparative properties facilitate effective recovery from such adversities. However, damage to respiratory basal cells or abnormalities in their function are associated with several respiratory pathologies such as asthma, chronic obstructive pulmonary disease, and lung cancer. Therefore, understanding these cells' function, and their role in disease, is crucial for the development of new therapeutic strategies for respiratory disorders.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0002633") +AnnotationAssertion(Annotation( "DOI:10.1007/s12079-019-00511-z") Annotation( "DOI:10.1016/j.cmet.2013.08.001") Annotation( "DOI:10.1101/cshperspect.a006569") Annotation( "DOI:10.3389/fcell.2021.642352") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Endothelial stalk cells are specialized vascular cells vital in angiogenesis, a process through which new blood vessels are formed from pre-existing ones; specifically, endothelial stalk cells are involved in sprouting angiogenesis, where they help form the body of new blood vessels. +Vascular sprouting relies on the coordinated activity of migrating endothelial tip cells at the forefront and proliferating stalk cells that elongate the sprout. The process is tightly controlled by different growths factors: Vascular Endothelial Growth Factor acts on endothelial cells, inducing them to become endothelial tip cells that initiate sprouting. After sprouting initiation, activation of Notch signaling suppresses differentiation toward a tip cell phenotype and some of the endothelial cells differentiate into stalk cells, which follow tip cells, multiply, and elongate to provide a structural backbone to the growing vessel sprout. +In contrast to endothelial tip cells, which migrate and lead the angiogenic sprout, endothelial stalk cells behind the sprouts continue forming the tube or lumen for blood flow and facilitate maturation and stability of the new vessel. The delicate balance between the activities of stalk and tip cells during angiogenesis is crucial to build a functional vascular network. Dysfunctions in endothelial stalk cells can lead to pathological conditions such as impaired wound healing, unregulated tumor growth, and metastasis due to abnormal angiogenesis.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0002671") +AnnotationAssertion(Annotation( "DOI:10.1016/j.jcf.2019.09.010") Annotation( "DOI:10.1038/s41586-018-0393-7") Annotation( "DOI:10.1038/s41598-023-30603-1") Annotation( "DOI:10.1146/annurev-pathol-042420-094031") Annotation( "DOI:10.3389/fmars.2020.00709") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Ionocytes are specialized cells predominantly found in the mammalian respiratory and renal systems as well as in the gills, skin, and intestinal tract of fish. These cells play crucial roles in maintaining ion and acid-base homeostasis. Ionocytes demonstrate remarkable plasticity and are able to adapt themselves in response to changes in environmental conditions such as pH, salinity, ion concentration, and temperature. +These cells work by selectively absorbing specific ions from the environment, thus maintaining the body's internal ionic balance. The most commonly absorbed ions include sodium (Na+), chloride (Cl-), calcium (Ca2+), and hydrogen (H+). Moreover, ionocytes contribute to acid-base regulation. In response to acidosis or alkalosis, ionocytes can either excrete or retain hydrogen (H+) and bicarbonate (HCO3-) ions to readjust the blood pH. Further, experimental evidence suggests a functional complexity of ionocytes, implying diverse roles beyond ion regulation. Recent research highlights ionocytes' involvement in ammonia excretion and the regulation of extracellular fluid volume, highlighting their contribution to the overall homeostatic process. +Malfunctioning ionocytes have been implicated in various diseases, including cystic fibrosis which is caused by mutations in the chloride channel CFTR, an ionocyte marker.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0005006") +AnnotationAssertion(Annotation( "DOI:10.1016/j.krcp.2013.07.005") Annotation( "DOI:10.2215/CJN.05760513") Annotation( "DOI:10.2215/CJN.08580813") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Renal principal cells are the major cell type in the initial collecting tubule and the cortical and outer medullary collecting ducts, as well as the connecting tubule, in the nephrons of the kidneys. +A key function of renal principal cells is the regulation of water balance in the body. These cells express aquaporin-2 (AQP2) water channels, which facilitate the reabsorption of water from the fluid within the renal tubule lumen back into the blood. The translocation of AQP2 to the cell membrane is controlled by the hormone vasopressin: In response to high vasopressin levels, AQP2 moves to the cell membrane, allowing water to pass through effectively and be reabsorbed, therefore concentrating the urine. Conversely, in low vasopressin conditions, AQP2 is removed from the membrane, reducing water reabsorption and diluting the urine. +Renal principal cells are also involved in the regulation of sodium and potassium levels in the body. They have sodium channels (ENaC) in their luminal membranes which permit the reabsorption of sodium ions from the tubule fluid back into the blood, resulting in a net reabsorption of sodium ions into the systemic circulation. This process is controlled, in part, by the hormone aldosterone. Additionally, renal principal cells contain potassium channels that facilitate the secretion of potassium ions into the urine. The activities of these channels, in coordination with other cell types in the nephron, are critical for maintaining electrolyte balance and overall body homeostasis.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0005009") +AnnotationAssertion(Annotation( "DOI:10.1152/ajprenal.2000.279.1.F195") Annotation( "DOI:10.1161/HYPERTENSIONAHA.121.16492") Annotation( "DOI:10.1681/ASN.V1011") Annotation( "DOI:10.2215/CJN.08880914") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Renal intercalated cells are specialized cells located in the collecting duct system of the kidneys. The primary role of intercalated cells is to reabsorb bicarbonate ions and secrete hydrogen ions, thereby maintaining the acid-base homeostasis in the blood. They comprise two main subtypes primarily distinguished by their functional and morphological attributes: alpha and beta intercalated cells. +Alpha intercalated cells are more predominant when the body is in a state of acidosis, a condition characterized by an increased acidity of the blood. These cells are specialized in secreting excessive hydrogen ions into the urine through a mechanism involving vacuolar H+-ATPase and H+/K+-ATPase pumps on their apical membranes. They simultaneously reabsorb bicarbonate ions from the tubular fluid and return them to the bloodstream via mechanisms involving carbonic anhydrase II and bicarbonate/chloride exchangers on the basolateral membrane. This dual process helps to increase blood pH towards normal levels. +When the body is in a state of alkalosis, a condition characterized by lowered levels of hydrogen ions in the blood, beta intercalated cells are more predominant. They primarily reabsorb hydrogen ions from the tubular fluid through vacuolar H+-ATPase and H+/K+-ATPase pumps on their basolateral membranes, while secreting bicarbonate ions into the urine via pendrin, a bicarbonate/chloride exchanger in the apical membrane. These mechanisms work together to decrease blood pH towards normal levels. +In summary, renal intercalated cells play a critical role in the delicate balance of the body’s pH, safeguarding the body from potential harm caused by acidemia or alkalemia.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0005010") +AnnotationAssertion(Annotation( "DOI:10.1016/j.semnephrol.2019.04.005") Annotation( "DOI:10.1152/physiol.00008.2011") Annotation( "DOI:10.1172/JCI63492") Annotation( "DOI:10.3390/diseases2020071") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Renal alpha-intercalated cells are located within the connecting tubules and collecting ducts of the kidneys, which are components of the kidney's complex nephron system. Along with beta-intercalated cells, they play a critical role in the body’s acid-base balance. +Renal alpha-intercalated cells contain an abundance of proton pumps and enzymes like carbonic anhydrase, which aid in the transport of hydrogen ions for secretion in the urine. The bicarbonate/chloride transporters on their apical membrane meanwhile take up bicarbonate ions from the urine and supply them back into the blood. Through this mechanism, these cells contribute significantly to the neutrality of blood pH, and dysfunction of renal alpha-intercalated cells often leads to distal renal tubular acidosis, a condition resulting in acidic blood and alkaline urine.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0005011") +AnnotationAssertion(Annotation( "DOI:10.1016/j.cub.2014.08.047") Annotation( "DOI:10.1038/nrm.2017.21") Annotation( "DOI:10.1101/cshperspect.a028233") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +The multi-ciliated epithelial cell are terminally differentiated epithelia that line brain ventricles, the respiratory tract and parts of the female and male reproductive organs in animals, playing critical roles in the maintenance of homeostasis through ciliary motion. They are characterized by the presence of hundreds of motile cilia, hair-like microtubule-based organelles that beat in a coordinated fashion to direct fluid flow over the cell surface. +Multi-ciliated epithelial cells have fundamental roles in the proper functioning of many organ systems. In the respiratory system, they line the airways and orchestrate the coordinated movement of mucus, effectively clearing the airways of inhaled particles and pathogens. These cells are also vital in the ventricular system of the brain where they facilitate cerebrospinal fluid circulation, thus contributing to the maintenance of the brain's microenvironment. In the fallopian tube, multi-ciliated epithelial cells aid in the transport of oocytes from the ovary to the uterus, a process crucial to reproduction. +The formation and function of multi-ciliated epithelial cells is a highly regulated process that involves several stages of development including cell specification, centriole multiplication, and ciliogenesis. Any disruption in these processes can result in dysfunctional or decreased numbers of cilia, which can lead to a myriad of health issues, ranging from chronic respiratory infections to infertility.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0005012") +AnnotationAssertion(Annotation( "DOI:10.1007/s00125-008-1238-y") Annotation( "DOI:10.1152/physrev.00012.2004") Annotation( "DOI:10.1210/en.2018-00833") Annotation( "DOI:10.3389/fendo.2022.904004") Annotation( "DOI:10.3390/ijms20081867") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Pancreatic epsilon cells are a specialized type of endocrine cell found in the islets of Langerhans, a region of the pancreas responsible for hormone production. These clusters of cells constitute only about 1% of the pancreatic islet cell population, making them a relatively small yet significant component of the pancreas. Pancreatic epsilon cells have a round or ovoid shape with occasional cytoplasmic extensions and are characterized by small and spherical granules. +The principal function of pancreatic epsilon cells involves the synthesis and release of the hormone ghrelin, a peptide hormone predominantly produced in the stomach; pancreatic epsilon cells are one of the few sites outside the gastrointestinal tract known to produce this hormone. Ghrelin has multiple vital roles, playing a significant part in generating hunger sensations, promoting fat storage, and influencing various metabolic processes. It also stimulates the release of Growth Hormone (GH) from the anterior pituitary gland. +During fetal development, when they form a layer around the islet, epsilon cells are an important source of ghrelin, likely secreting the hormone into the circulation; their numbers decrease in adults. While research on pancreatic epsilon cells is still ongoing, these cells have been implicated in several disease states, most notably Type 2 diabetes and metabolic syndrome. The dysfunction or reduction in the number of pancreatic epsilon cells can lead to anomalies in ghrelin production, impacting overall metabolic homeostasis and glucose regulation.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0005019") +AnnotationAssertion(Annotation( "DOI:10.1016/j.stem.2014.04.010") Annotation( "DOI:10.1093/jb/mvr001") Annotation( "DOI:10.1242/dev.031369") Annotation( "DOI:10.1242/dev.114215") Annotation( "DOI:10.5966/sctm.2015-0051") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Hepatoblasts are immature precursor cells that predominate during the early stages of liver development, specifically in the embryonic phase of life. They first arise from the endoderm, one of the three primary germ layers in the very early embryo, and then differentiate into two distinct mature liver cell types - the hepatocytes and cholangiocytes. +During liver organogenesis hepatoblasts proliferate and migrate into the septum transversum to form the liver bud. Proliferation and differentiation of these cells are regulated by several soluble factors, such as hepatocyte growth factor, which is a mitogen of both hepatoblasts and mature hepatocytes. As they start to differentiate into hepatocytes and cholangiocytes, the cells begin to express hepatic markers like albumin and alpha-fetoprotein. +Although hepatoblasts are specified embryonic liver cells that are bipotential for hepatocytes and cholangiocytes, a subset of liver cells (called oval cells) has been identified in adults that express stem cell markers, such as CD133 and cKIT, and has been suggested to have the same potential as hepatoblasts to differentiate into hepatocytes and cholangiocytes.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0005026") +AnnotationAssertion(Annotation( "DOI:10.1016/j.celrep.2020.107952") Annotation( "DOI:10.1038/s41575-018-0081-y") Annotation( "DOI:10.1073/pnas.1607327113") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Intestinal crypt stem cells of the small intestine are a type of adult stem cell intimately involved in the continuous replenishment of the intestinal epithelium, the innermost layer of the intestine responsible for nutrient absorption. These cells, located within the crypts of Lieberkühn, are the origin of various cell lineages that make up the functional units of the small intestine. They possess self-renewal ability, an essential feature of stem cells, which allows them to maintain a steady population in the small intestine. +One of the critical roles of intestinal crypt stem cells is to drive the continual renewal process taking place in the small intestine every 3-5 days. By proliferating intensively, these cells produce transient amplifying (TA) cells that are characterized by quick division and progressive differentiation. These cells eventually differentiate into specialized cell types, encompassing absorptive enterocytes, mucin-secreting goblet cells, hormone-secreting enteroendocrine cells, and Paneth cells, all of which have essential roles in digestion and nutrient absorption in the small intestine. +Intestinal crypt stem cells of the small intestine are also play a significant part in injury recovery. Under regular conditions, these cells primarily exist in an active state, facilitating the constant renovation of the gut lining. However, upon injury or loss of regular intestinal crypt stem cells reserve intestinal stem cells, a slow-cycling and radio-resistant population, can be stimulated to take over the duties of active crypt stem cells. Such plasticity provides a powerful regenerative mechanism that ensures the intestinal epithelium's function and structural integrity amidst diverse conditions.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0009017") +AnnotationAssertion(Annotation( "DOI:10.1016/j.cell.2013.07.004") Annotation( "DOI:10.1038/s41575-018-0081-y") Annotation( "DOI:10.1073/pnas.1607327113") Annotation( "DOI:10.1111/j.1365-2184.2009.00642.x") Annotation( "DOI:10.1186/s12943-019-0962-x") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Intestinal crypt stem cells of the colon, also known as colon crypt base columnar (CBC) cells, are highly specialized cells primarily responsible for the constant self-renewal of the colonic epithelium. These cells are found in the crypts of Lieberkühn - deeply invaginated sections of the colon's mucosal layer. +The prime function of intestinal crypt stem cells of the colon is to serve as the source of constant cell regeneration in the colon. Every few days, these stem cells divide and differentiate into the various other types of intestinal cells, such as enterocytes, goblet cells, and enteroendocrine cells. +A constant renewal cycle is necessary due to the harsh environment of the colon where cells continuously encounter abrasive food matter and potential pathogens, leading to a high turnover rate. When the colon's mucosal layer suffers damage, a rapid response is triggered whereby colon crypt stem cells divide faster and are directed to injured sites to repair the epithelial layer. Dysregulation of these cells' function or proliferation can contribute to disorders such as colorectal cancer.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0009043") +AnnotationAssertion(Annotation( "DOI:10.1002/dvg.23276") Annotation( "DOI:10.1242/dev.193193") Annotation( "DOI:10.3389/fcell.2020.00635/full") Annotation( "https://doi.org/10.1016/j.ydbio.2011.12.042") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Neural crest cells are a group of transient and highly migratory cells that originate from the neuroectoderm during the early stages of embryonic development. They are multipotent cells with an exceptional degree of plasticity, capable of differentiating into various somatic cell types and therefore play a fundamental role in the formation of various organs and tissues, making them critical contributors to the developing embryo. +After the initiation of neurulation (the formation of the neural tube) neural crest cells start to undergo epithelial-to-mesenchymal transition and delaminate and migrate from the dorsal neural tube to several regions throughout the embryo. They differentiate into a range of diverse cell types, such as neurons and glial cells of the peripheral nervous system, including sensory and autonomic neurons. They also contribute to the formation of adrenal glands, pigment cells in the skin (melanocytes), cardiac structures, including parts of the heart septum and major arteries, as well as bones and cartilage of the face and skull. +Disorders or aberrations in the development or migration of the neural crest cells can lead to serious congenital malformations, such as neurocristopathies, including Hirschsprung disease, neuroblastoma, and neurofibromatosis.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0011012") +AnnotationAssertion(Annotation( "DOI:10.1038/s41586-018-0393-7") Annotation( "DOI:10.1146/annurev-pathol-042420-094031") Annotation( "DOI:10.1172/JCI171268") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +The pulmonary ionocyte is a relatively newly identified, specific epithelial cell type found primarily in the pulmonary or respiratory system. Discovered through novel mapping techniques in 2018, these cells are surprisingly rare, making up less than 2% of the cells in the lung's airway, yet they play an essential role in the airway surface liquid and mucus regulation, a crucial factor in lung health. +The main responsibility of the pulmonary ionocyte pertains to the regulation and mobilization of chloride ions. They express a high level of CFTR (Cystic Fibrosis Transmembrane Conductance Regulator) gene, which encodes a protein channel across the membrane of cells that produce mucus, sweat, saliva, tears, and digestive enzymes. The activity of CFTR regulates the movement of chloride ions and fluids in and out of cells, which helps maintain a balance of fluid in the organs they are expressed in. If CFTR is dysfunctional, it can cause conditions such as cystic fibrosis, characterized by thick, sticky mucus that can clog the lungs and obstruct the pancreas, leading to respiratory and digestive issues. +The discovery of this cell type offers new doors to the treatment and further understanding of diseases like cystic fibrosis. Increased understanding of pulmonary ionocytes could contribute to the development of novel therapeutic approaches to manipulate the function of CFTR in the lungs and other organs affected by dysfunctional CFTR.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_0017000") +AnnotationAssertion(Annotation( "DOI:10.1038/s41385-018-0039-y") Annotation( "DOI:10.1038/s41385-020-00370-7") Annotation( "DOI:10.1159/000512268") Annotation( "DOI:10.1513/AnnalsATS.201802-128AW") Annotation( "https://www.ncbi.nlm.nih.gov/books/NBK553208/") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Lung goblet cells are critical components of the respiratory tract, specifically found in the bronchial segments. They are secretory epithelial cells known for their signature \"goblet\" or cup-like shape. Their primary function is to produce and secrete mucus that aids in trapping airborne particles and pathogens, preventing them from reaching the delicate environment of the lung. As part of the lung's epithelial lining, they act as frontline defenders, maintaining lung health and function. +The lung goblet cells are densely packed with granules containing mucin glycoproteins, the primary component of mucus. As mucus is produced and secreted, it moves towards the lumen of the lungs where the cilia, hair-like structures of the neighboring ciliated epithelial cells, help to navigate it upwards and out of the respiratory tract. This coordinated action ensures the expulsion of unwanted particles and pathogens, effectively cleaning the respiratory tract. +Dysfunction or abnormal proliferation of lung goblet cells can result in pathological conditions such as chronic obstructive pulmonary disorder (COPD) and asthma, where excessive mucus production leads to airway obstruction. Furthermore, lung goblet cells respond to a variety of stimuli, including toxins, allergens, irritants, and infections, adjusting their mucus production accordingly.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_1000143") +AnnotationAssertion(Annotation( "DOI:10.1016/bs.ctdb.2018.12.002") Annotation( "DOI:10.1016/j.devcel.2020.09.024") Annotation( "DOI:10.1242/dmm.046920") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Lung neuroendocrine cells, also commonly known as pulmonary neuroendocrine cells (PNECs), are predominantly located in the respiratory epithelium of the bronchial and bronchiolar airways in the lungs. These cells, characterised by their small size and granular appearance, have a distinctive morphology that sets them apart from other lung cells. They are considered part of the diffuse neuroendocrine system due to their scattered distribution through the epithelium and have been classified into solitary cells and clustered forms known as neuroepithelial bodies. +The primary function of PNECs is linked to regulation and maintenance of the lung environment. They are sensory in nature and can secrete various bioactive substances such as serotonin, calcitonin, calcitonin gene-related peptides, and bombesin-like peptides which modulate airway smooth muscle tone and influence gut motility. For example, they act as oxygen sensors in response to hypoxia and are responsible for releasing neuropeptides that can induce responses. Moreover, PNECs provide an afferent function as they are equipped with long microvilli that project into the lumen of the bronchus and react to changes in the chemical composition of the luminal content.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_1000223") +AnnotationAssertion(Annotation( "DOI:10.1038/nrgastro.2013.35") Annotation( "DOI:10.1038/nri3738") Annotation( "DOI:10.1084/jem.20191130") Annotation( "DOI:10.3389/fphys.2021.699152/full") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Enterocytes of the epithelium of the small intestine are specialized cells that reside in the lining of the small intestine, and are primarily responsible for the essential process of nutrient absorption. These cells are columnar epithelial cells with an apical surface lined with microvilli, a feature referred to as the 'brush border', to maximize the surface area available for absorption. +Enterocytes play a critical role in both the digestion and absorption of nutrients from food. Their extensive brush border contains enzymes that further assist in nutrient breakdown and transport proteins that transfer nutrients, such as glucose, amino acids, lipids, and vitamins, across the cell membrane. +The enterocytes of the small intestine also participate in the barrier function of the gut lining. Enterocytes are connected by tight junctions, which act as a primary defense line against pathogenic invasion by maintaining intestinal barrier integrity. Additionally, their cell surface is coated in glycocalyx and mucus which forms a defensive barrier preventing the penetration of harmful bacteria into the systemic circulation.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_1000334") +AnnotationAssertion(Annotation( "DOI:10.1038/nri3738") Annotation( "DOI:10.1084/jem.20191130") Annotation( "DOI:10.1111/j.1365-2249.2011.04523.x") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Enterocytes of the epithelium proper of the ileum, commonly known as ileal enterocytes, are specialized epithelial cells found lining the inner surface of the ileum, the final section of the small intestine in the human body. They play a pivotal role in nutrient absorption, digestive metabolic functions, and the maintenance of the host’s immune response. +Like enterocytes in other parts of the intestine, ileal enterocytes exhibit distinct characteristics specific to their function and role. They have microvilli on their apical surfaces to increase absorption and are important in the absorption of vitamins and the reabsorption of bile salts. These cells also produce enzymes that metabolize lipids and xenobiotics.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_1000342") +AnnotationAssertion(Annotation( "DOI:10.1007/s11894-010-0130-3") Annotation( "DOI:10.1038/nrgastro.2013.35") Annotation( "DOI:10.1038/nri3738") Annotation( "DOI:10.1084/jem.20191130") Annotation( "DOI:10.3389/fimmu.2019.00277") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Enterocytes of the colon are specialized epithelial cells located in the lining of the colon, the largest part of the large intestine. These cells play a critical role in absorbing water, electrolytes, and certain vitamins from the food material passed on from the small intestine. With a unique structure of finger-like protrusions referred to as microvilli, the enterocytes increase their surface area for effective absorption. The colon is the last part of the digestive system, and as such, it is responsible for compacting undigested food materials and forming fecal matter. Enterocytes of the colon facilitate this process effectively through absorption of water. +Enterocytes are known for their high regeneration potential, replenishing every 4-5 days, enabling the healthy functioning of the colon. They originate from stem cells located in the crypt of the colon and differentiate into mature enterocytes as they migrate upwards towards the luminal surface. This constant turnover aids in maintaining the intestinal barrier, preventing the entry of detrimental substances into the systemic circulation. Their tight junctions with other epithelial cells provide a robust barrier against invasive pathogens. +Enterocytes of the colon are involved in the communication with the gut microbiota. These cells harbor enzymes necessary for the metabolism of short-chain fatty acids, which are the byproducts of the fermentation process by gut bacteria. Short-chain fatty acids serve as a major energy source for colonocytes and are important for maintaining colonic health. The dysfunction of enterocytes, therefore, could lead to disorders such as inflammatory bowel disease or colorectal cancer.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_1000347") +AnnotationAssertion(Annotation( "DOI:10.1007/s00441-008-0706-5") Annotation( "DOI:10.1007/s10456-021-09785-7") Annotation( "DOI:10.1016/j.ccm.2021.08.005") Annotation( "DOI:10.1016/j.jvs.2004.03.043") Annotation( "DOI:10.1177/153857440303700107") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Endothelial cells of the artery, also referred to as arterial endothelial cells, form an integral part of the arterial system. They form a single layer, known as the endothelium, lining the interior surface of arteries, and are able to respond to the high-pressure and flow conditions present in arteries. The primary role of these cells is to provide a barrier between the vessel wall and the blood, exhibiting selective permeability to regulate the movement of liquids, gases, and blood-borne substances across the vascular wall. +Arterial endothelial cells significantly contribute to maintaining vascular homeostasis. They are at the forefront of sensations and responses to mechanical stimuli, like shear stress and blood pressure changes. An additional key function pertains to the production of nitric oxide, which helps to regulate vascular tone and blood pressure, prevents platelet aggregation, limits leukocyte adhesion to the endothelium, and inhibits smooth muscle cell proliferation. These varied but connected functions help to preclude the development of atherosclerosis, ensuring normal circulation and arterial health. +Moreover, these cells play a pivotal role in inflammation and coagulation processes. During inflammatory events, they express various adhesion molecules, aiding in leukocyte recruitment and rolling onto the vessel walls for immune response. They also produce anticoagulant and procoagulant substances, involved in blood clotting and clot dissolution, respectively. Dysregulation of the usual functions of arterial endothelial cells can result in serious pathophysiological conditions, such as atherosclerosis, hypertension, and other cardiovascular diseases.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_1000413") +AnnotationAssertion(Annotation( "DOI:10.1007/s004290050160") Annotation( "DOI:10.1111/j.1442-9071.2012.02818.x") Annotation( "DOI:10.1167/tvst.8.4.32") Annotation( "DOI:10.2147/OPTH.S26048") Annotation( "DOI:10.3389/fimmu.2022.918619") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Epithelial cells of the lacrimal sac play a significant role in the physiology of tear drainage, acting as an integral part of the lacrimal drainage system. The lacrimal sac is part of the nasolacrimal duct system, a conduit which connects the eye to the nasal cavity, and is lined by multilayered, non-keratinizing, squamous epithelial cells. +The epithelial cells of the lacrimal sac are specialized for the purpose of maintaining a moist environment and protecting the surface of the eye. They form a barrier that traps and removes potential contaminants from the tear film during the drainage process. These cells also actively contribute to tear turnover by expediting the drainage of excess tears. Dysfunctional epithelial cells of the lacrimal sac can lead to dacryocystitis, a condition characterized by inflammation of the lacrimal sac. +Epithelial cells of the lacrimal sac also perform various other tasks which ensure the overall health of the eye. They are involved in the regulation of immune responses within the lacrimal apparatus and may have a possible role in host-microbiome interactions. Thus, epithelial cells of the lacrimal sac play a multifaceted role in tear drainage and ocular surface defence, directly translating to eye health and vision quality.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_1000436") +AnnotationAssertion(Annotation( "DOI:10.1016/j.ajpath.2014.01.014") Annotation( "DOI:10.1016/j.semnephrol.2019.04.005") Annotation( "DOI:10.2215/CJN.05760513") Annotation( "DOI:10.2215/CJN.08880914") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Kidney collecting duct epithelial cells are a specialized type of cells that form an integral part of the renal system. Located in the collecting duct system of the kidneys, these cells are responsible for one of the final steps in the process of urine formation, and they are instrumental in the fine tuning of the volume and composition of urine by reabsorbing water and certain solutes back into the bloodstream. +These cells express specific channels and carriers that actively and passively transport ions and water. They also have channels on their membranes, such as sodium channels and potassium channels, involved in reabsorbing or secreting these electrolytes depending upon the body's needs. The function of renal collecting duct epithelial cells can be regulated by a variety of hormones, including vasopressin (antidiuretic hormone), which can modulate the ion channels and carriers and hence indirectly influence body fluid homeostasis. +Aside from their function in ion and water balance, kidney collecting duct epithelial cells also aid in maintaining the body's acid-base balance. They have specialized functionality to secret hydrogen ions into the tubular lumen, which contributes to acid excretion. Any dysfunction may have serious implications and lead to various renal or systemic diseases, exemplifying the importance of these cells in maintaining overall body homeostasis.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_1000454") +AnnotationAssertion(Annotation( "DOI:10.1016/j.jcmgh.2015.05.005") Annotation( "DOI:10.1016/j.jhep.2012.10.011") Annotation( "DOI:10.1038/s41575-019-0125-y") Annotation( "DOI:10.1152/ajpgi.00227.2012") Annotation( "DOI:10.5009/gnl16033") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Cholangiocytes, also known as biliary epithelial cells, are specialized epithelial cells that line the biliary tract, which constitutes the gall bladder and bile ducts inside the liver. Crucial to the maintenance of the liver's health and function, cholangiocytes have a key role in the modification and secretion of bile, a fluid produced by hepatocytes that is essential to digestion and the absorption of fats and vitamins. +Cholangiocytes accomplish their primary function through the expression of a variety of transport proteins located on their apical and basolateral membranes, which propel bile acids and other contents of the bile into the biliary lumen. The hepatic bile, once secreted by the hepatocytes, is further modified by cholangiocytes via secretion and absorption processes. These processes help in the regulation of bile volume and composition, which is fundamental in ensuring the efficient digestion of dietary fats and fat-soluble vitamins and the excretion of cholesterol. +In addition to their role in bile modification, cholangiocytes also perform several other integral functions. For instance, these cells express Toll-like receptors (TLRs) which allow cholangiocytes to initiate an immune response against pathogens in the biliary lumen. When functioning normally, these cells contribute to biliary integrity, hepatic architecture, and overall hepatic physiology. However, when they become pathological, they are involved in the progression of liver diseases, such as primary biliary cirrhosis and cholangiocarcinoma – the malignancy of the biliary tract.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_1000488") +AnnotationAssertion(Annotation( "DOI:10.1016/j.ccm.2021.08.005") Annotation( "DOI:10.1016/j.coi.2020.04.005") Annotation( "DOI:10.1152/ajplung.90587.2008") Annotation( "DOI:10.3389/fphys.2014.00284") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Mesothelial cells of the pleura form a significant part of the pleural membrane, a thin, double-layered serous membrane that lines the thoracic cavity and encompasses the lungs. These specialized cells contribute to the pleura's key function of producing a lubricating serous fluid, which reduces friction between the lung's outer surface (visceral pleura) and the inner lining of the thoracic cavity (parietal pleura) during respiration. +The cellular structure of mesothelial cells, characterized by microvilli on their surface, aids in the secretion and absorption of the pleural fluid, effectively supporting the smooth expansion and contraction of the lungs. Dysregulation in mesothelial cells can lead to pathologies, including pleural effusion and malignant mesothelioma. +Mesothelial cells of the pleura display unique immunologic properties. They act as a first line of defense against infection because they are able to recognize pathogens and respond by secreting various cytokines and chemokines. Additionally, these cells are directly involved in the translocation of immune cells into the pleural cavity during inflammatory response, thereby playing an active role in the immune response within the pleural environment. +In the event of pleural injury, these cells are also involved in the mesothelial-mesenchymal transition, a process that allows mesothelial cells to transdifferentiate into myofibroblasts and promote tissue repair.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_1000491") +AnnotationAssertion(Annotation( "DOI:10.1016/S1357-2725(03)00242-5") Annotation( "DOI:10.1152/physrev.00026.2003") Annotation( "DOI:10.1371/journal.pone.0276978") Annotation( "DOI:10.3389/fphys.2014.00221") Annotation( "DOI:10.3390/jdb7020007") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Mesothelial cells of visceral pleura are specialized epithelial cells that line the inner layer of the pleura, the membrane that envelops the lungs. Positioned adjacent to the lung tissue, these cells form a protective barrier and contribute to the structure of the visceral pleura. They are characterized by their cuboidal to squamous epithelial shape and the presence of microvilli on their surface, a feature aiding in fluid and solute exchange between the pleura and the lungs. +The primary function of mesothelial cells of visceral pleura is to secrete a lubricating serous fluid to facilitate smooth, frictionless lung movement within the thoracic cavity during respiration. This helps in the prevention of trauma or damage stemming from the constant rubbing of the lung tissue against the chest wall, hence playing a pivotal role in maintaining respiratory function. Besides fluid secretion, these cells have an essential role in the transportation of fluids and particles across the pleura, as well as in inflammation, wound healing, and tissue repair processes within the pleura. +Mesothelial cells of visceral pleura are notably implicated in the development of pleural diseases such as pleural effusion and pleural mesothelioma, a rare and aggressive form of cancer primarily linked with exposure to asbestos. Alterations, such as hyperplasia or metaplasia, may occur in these mesothelial cells under pathological conditions.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_1000493") +AnnotationAssertion(Annotation( "DOI:10.1016/j.biocel.2010.05.015") Annotation( "DOI:10.1016/j.yexcr.2012.02.032") Annotation( "DOI:10.1111/j.1523-1755.2005.00260.x") Annotation( "DOI:10.2337/diacare.28.1.164") Annotation( "DOI:10.3389/fphys.2021.689083") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +The glomerular capillary endothelial cell comprises an intrinsic component of the glomerulus in the kidney. Glomeruli contain a network of capillaries where the first step of blood filtration takes place, with glomerular capillary endothelial cells acting as an integral part of this process. Unlike regular endothelial cells that line the vasculature, unique fenestrations (openings) characterize these cells, allowing for enhanced permeability and filtration efficacy. +Together with the glomerular basement membrane and podocytes, the glomerular endothelial cells form the glomerular filtration barrier, which is responsible for blood filtration and therefore critical for removal of waste products, such as urea and creatinine, and excess substances, such as glucose and ions, from the bloodstream. The glomerular capillary endothelial cells' fenestrations permit the free flow of a variety of particles, barring larger, negatively charged proteins like serum albumin, enabling the formation of an ultrafiltrate. This ultrafiltrate is the primitive form of urine, which then passes through the proximal tubule for further processing and ultimately helps maintain systemic fluid and electrolyte balance. +Moreover, the glomerular capillary endothelial cells are also believed to play a crucial role in renal pathologies. Any compromise to their structural integrity or functional performance can lead to kidney diseases, including but not limited to, diabetic nephropathy and glomerulonephritis. For instance, in diabetes, persistent hyperglycemia can injure these cells, leading to a compromised glomerular filtration barrier and proteinuria, indicating the loss of proteins in the urine.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_1001005") +AnnotationAssertion(Annotation( "DOI:10.1046/j.0001-6772.2003.01205.x") Annotation( "DOI:10.1093/ndt/gfl308") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Kidney afferent arteriole endothelial cells are a specialized type of cell located within the kidneys, forming the inner lining of the afferent arterioles, which are responsible for delivering blood to the glomeruli - capillary networks responsible for filtration - from where the process of urine formation begins in the nephrons. +The endothelial cells in the kidney afferent arterioles have a key function in regulating the blood flow and filtration. They have autocrine and paracrine signaling capabilities, meaning they can signal to themselves and other nearby cells. They produce nitric oxide, prostacyclin, and endothelin, which are powerful vasodilators and vasoconstrictors that regulate renal blood flow. These cells also engage in the mitigation of kidney injury and inflammation by promoting repair and regeneration, demonstrating the multifaceted roles these cells play in maintaining renal health.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_1001096") +AnnotationAssertion(Annotation( "DOI:10.1016/j.semcdb.2014.08.002") Annotation( "DOI:10.1016/j.semnephrol.2015.01.010") Annotation( "DOI:10.1038/s41581-021-00411-9") Annotation( "DOI:10.1681/ASN.2019111179") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Kidney efferent arteriole endothelial cells constitute a vital component of the kidney's microvascular system. They are unique endothelial cells found lining the walls of efferent arterioles, which transport blood away from the glomeruli in the kidney. +The primary responsibilities of the kidney efferent arteriole endothelial cells involve controling renal blood flow, regulating glomerular filtration rate (GFR), and managing perfusion pressure. They do this by contracting and relaxing, effectively narrowing and widening the arteriole's lumen thereby controling the volume and rate of blood flow to the peritubular capillaries and creating the pressure gradient necessary for filtration in the glomerulus. +Furthermore, kidney efferent arteriole endothelial cells show a high degree of plasticity in response to pathophysiological stimuli and can undergo structural and functional changes based on local needs. In conditions like hypertension and diabetes, these cells can experience hypertrophy and endothelial dysfunction, contributing to the progression of renal disease.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_1001099") +AnnotationAssertion(Annotation( "DOI:10.1016/B978-0-323-35515-5.00009-9") Annotation( "DOI:10.1053/j.ajkd.2005.01.008") Annotation( "DOI:10.1081/jdi-100101958") Annotation( "DOI:10.1111/apha.12026") Annotation( "DOI:10.1152/ajpregu.00657.2002") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +The vasa recta ascending limb cells are specialized epithelial cells that are part of the vasa recta in the kidney, a crucial component of the renal medulla that functions as a counter-current exchanger to maintain the concentration gradient required for water reabsorption. These particular cells are located in the ascending limb of the vasa recta, which takes blood flow from the medulla back to the cortex. +The primary function of vasa recta ascending limb cells is to preserve the renal medulla's hypertonicity, necessary for the kidney's urine concentration mechanism. Unlike the vasa recta descending limb cells, the venous-like epithelial cells of the ascending vasa recta are highly fenestrated and lack pericyte coverage, which facilitates water reuptake. +As the blood flows through the ascending limb, it loses solutes and gains water, which is driven by the high solute concentration in the surrounding interstitium. This process acts in concert with cellular action in the descending limb and contributions from the so-called Loop of Henle, which helps with water and sodium chloride retrieval from the urine. +In the context of normal physiological processes, the function of the vasa recta ascending limb cells is essential in maintaining the body's overall fluid balance, electrolyte concentration, and systemic blood pressure. Any dysfunction in these cells may lead to impaired urine concentration or dilution capability of the kidney, potentially resulting in conditions like diabetes insipidus or hyponatremia.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_1001131") +AnnotationAssertion(Annotation( "DOI:10.1053/j.ajkd.2005.01.008") Annotation( "DOI:10.1081/jdi-100101958") Annotation( "DOI:10.1111/apha.12026#apha12026-bib-0039") Annotation( "DOI:10.1152/ajpregu.00657.2002") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Vasa recta descending limb cells are specialized epithelial cells found in the vasa recta, a network of blood vessels in the renal medulla. These cells line the interior surface of the descending limb of the vasa recta and play a crucial role in the filtering and regulation of substances within the blood. +In contrast to vasa recta ascending limb cells, the arterial-like epithelial cells of the descending vasa recta are non-fenestrated and covered by a pericyte layer that regulates the medullary blood flow. They help keeping the body’s fluid and electrolyte balance in check through a process known as countercurrent exchange system, in which the cells of the descending limb are permeable to water but relatively impermeable to solutes, such as sodium and urea. As the blood descends into the medulla along its descending limb, water passively diffuses out of the vasa recta, concentrating the blood in solutes. +In addition to their central role in water and solute exchange, these cells contribute to maintaining the medullary osmotic gradient, a critical function to concentrate urine. The osmotic gradient is created by the counterflow of water and solutes between the descending and ascending limbs of the vasa recta and the adjacent Loop of Henle. The selective permeability of the descending limb cells allows them to maintain this gradient, which in turn helps to conserve water, a vital role in the overall function of the renal system. Thus, vasa recta descending limb cells have a significant function in renal physiology, particularly in osmoregulation and fluid balance.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_1001285") +AnnotationAssertion(Annotation( "DOI:10.1007/s11906-015-0538-0") Annotation( "DOI:10.1016/B978-0-12-386456-7.05402-2") Annotation( "DOI:10.1016/j.biocel.2022.106261") Annotation( "DOI:10.1073/pnas.1710964114") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +The kidney collecting duct principal cell is a highly specialized type of cell found in the late distal convoluted tubule and collecting duct of the kidney's nephron. Principal cells are located at the final segments of the renal tubules, where they play a pivotal role in key homeostatic processes. +One of their fundamental functions of kidney collecting duct principal cells is the regulation of water reabsorption, which is mediated by aquaporins (water channel proteins). Antidiuretic hormones, such as vasopressin, can stimulate the redistribution of these water channels from an intracellular pools to the apical plasma membrane of the principal cell; translocation of aquaporin (specifically, AQP2) is associated with an increase of osmotic water permeability. The water reabsorption affects the concentration of the final urine; these cells are therefore directly involved in the maintenance of the body's fluid balance. +Kidney collecting duct principal cells also participate in sodium and potassium ions regulation. They reabsorb sodium ions from the tubular fluid back into the bloodstream, a process facilitated by the action of aldosterone, a hormone released by the adrenal glands. Similarly, the principal cells secrete potassium ions into the tubular fluid in response to aldosterone, contributing to the regulation of potassium levels in the body. Impaired function of cells can lead to various renal diseases and disorders, highlighting the vital role of kidney collecting duct principal cells in the body's homeostatic processes.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_1001431") +AnnotationAssertion(Annotation( "DOI:10.1007/978-3-030-32300-4_26") Annotation( "DOI:10.1007/s00265-006-0178-0") Annotation( "DOI:10.1111/j.1439-0272.1992.tb02636.x") Annotation( "https://www.ncbi.nlm.nih.gov/books/NBK499854/") Annotation( "https://www.sciencedirect.com/topics/veterinary-science-and-veterinary-medicine/seminal-vesicle") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Seminal vesicle glandular cells belong to a specialized group of epithelial cells that form the internal lining of the seminal vesicles, a pair of male reproductive organs. These cells are located within the complex tubuloalveolar glands that make up the seminal vesicles and are known for their unique pseudostratified columnar epithelium structure. +The primary function of these cells is the secretion of a variety of substances that ultimately constitute around 70% of the fluid volume of semen. Seminal cells produce a high-fructose fluid that serves as an energy source for the spermatozoa and promotes their motility. They also secrete other essential substances like proteins, enzymes, vitamin C, prostaglandins, and various other compounds. Collectively, these substances help in the nourishment, protection, and transportation of the spermatozoa throughout the male reproductive system and during the ejaculation process. +Secondary to the production of seminal fluid, the seminal vesicle glandular cells also play a role in the contraction of the seminal vesicles during ejaculation. The contraction of these glands, induced by sympathetic nerves, ensures the efficient propulsion of the seminal fluid mixed with spermatozoa into the ejaculatory ducts and subsequently to the urethra. Notably, any malfunction or pathological condition affecting these cells can impact male fertility, emphasizing the importance of understanding the intricate functions of seminal vesicle glandular cells in maintaining the healthy physiological function of male reproduction.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_1001597") +AnnotationAssertion(Annotation( "DOI:10.1002/(SICI)1097-0029(19980415)41:2<98::AID-JEMT2>3.0.CO;2-M") Annotation( "DOI:10.1111/joa.13709") Annotation( "DOI:10.3389/fncel.2015.00480") "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + +Hypendymal cells are secretory cells located between the ependymal layer and the posterior commissure, forming the hypendmal layer of the subcommissural organ (SCO), a highly conserved gland that is part of the circumventricular system within the brain. +Hypendymal cells are bipolar cells with a thin apical pole and basal process. Most of the ultrastructural characteristics of these cells are similar to those described for the ependymal cells (which are arranged into another layer – the ependyma). However, ependymal cells release their secretion into the ventricular cerebrospinal fluid whereas hypendymal cells project processes to the local blood vessels and to the subarachnoidal space.") +AnnotationAssertion( "https://cellxgene.cziscience.com/cellguide/CL_4023181") ) \ No newline at end of file diff --git a/src/patterns/dosdp-patterns/ExtendedDescription.yaml b/src/patterns/dosdp-patterns/ExtendedDescription.yaml new file mode 100644 index 000000000..08da07bd1 --- /dev/null +++ b/src/patterns/dosdp-patterns/ExtendedDescription.yaml @@ -0,0 +1,41 @@ +pattern_name: ExtendedDescription +pattern_iri: http://purl.obolibrary.org/obo/cl/ExtendedDescription + +description: A pattern for adding external extended descriptions with a boilerplate disclaimer. + +contributors: + - https://orcid.org/0000-0002-7073-9172 + +annotationProperties: + description: dct:description + xref: oio:hasDbXref + +data_vars: + desc: xsd:string + CL_short_form: xsd:string + +data_list_vars: + pubs: xsd:string + +annotations: + - + annotationProperty: description + text: "This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies to only to some subtypes and species, and so should not be considered definitional. + + + %s" + vars: + - desc + annotations: + - annotationProperty: xref + value: pubs + + - + annotationProperty: xref + text: "https://cellxgene.cziscience.com/cellguide/%s" # better if we can make this type IRI? + vars: + - CL_short_form + + + +