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256 Sentences With "epithelia"

How to use epithelia in a sentence? Find typical usage patterns (collocations)/phrases/context for "epithelia" and check conjugation/comparative form for "epithelia". Mastering all the usages of "epithelia" from sentence examples published by news publications.

This is a tumor that&aposs made up of epithelia vascular cells, that&aposs the material that&aposs made of -- bigger artery is made out of.
You also have to take into account that the inside of your mouth, down to the opening of the stomach, is covered in what's called stratified epithelia—similar to but not the same as the skin—and so that will add quite substantially to this amount over one's entire lifetime.
Philadelphia: W.B. Saunders Company, 2002. pages 23. and junctional epithelia do not.
Research suggests that in vertebrate evolution, sensory cells became specialized as gravistatic sensors after they became assembled to form the ear. After this aggregation, growth, including duplication and segregation of existing neurosensory epithelia, gave rise to new epithelia and can be appreciated by comparing sensory epithelia from the inner ears of different vertebrates and their innervation by different neuronal populations. Novel directions of differentiation were apparently further expanded by incorporating unique molecular modules in newly developed sensory epithelia. For example, the saccule gave rise to the auditory epithelium and corresponding neuronal population of tetrapods, starting possibly in an aquatic environment.
Tight junctions present in different types of epithelia are selective for solutes of differing size, charge, and polarity.
The renal SLC4A4 gene product NBCe1-A is specifically expressed in the basolateral membranes of proximal tubule epithelia.
Many genes with elevated expression are also shared with skin and other organs that are composed of squamous epithelia.
Not all ciliated cells extend to the luminal surface; such cells are capable of cell division providing replacements for cells lost or damaged. Pseudostratified epithelia function in secretion or absorption. If a specimen looks stratified but has cilia, then it is a pseudostratified ciliated epithelium, since stratified epithelia do not have cilia.
The freezing causes injuries in the epithelia and makes the nutrients in the underlying plant tissues available to the bacteria.
LEKTI may play a role in skin and hair morphogenesis and anti-inflammatory and/or antimicrobial protection of mucous epithelia.
However, EpCAM is not found in non-epithelial cells or cancers of non-epithelial origin. EpCAM is expressed on the basolateral membrane of all simple (especially glandular), pseudo-stratified, and transitional epithelia. In contrast, normal squamous stratified epithelia are negative for EpCAM. The level of expression may differ significantly between the individual tissue types.
Recent studies provided evidence that IL-30 is implicated in prostate cancer progression. IL-30, absent in normal prostatic epithelia, was found to be expressed by cancerous epithelia. IL-30 expression by prostate cancer epithelia and leukocytes infiltrating tumor and draining lymph nodes correlates with high-grade and advanced-stage prostate cancer. IL-30 promotes prostate cancer stem-like cells viability, self-renewal ability, tumorigenic and metastatic potential, it regulates, essentially via STAT1 and STAT3 signaling, a range of proinflammatory and chemokine/chemokine-receptor genes that promote tumor growth.
This gene encodes the alpha chain of type VII collagen. The type VII collagen fibril, composed of three identical alpha collagen chains, is restricted to the basement zone beneath stratified squamous epithelia. It functions as an anchoring fibril between the external epithelia and the underlying stroma. Mutations in this gene are associated with all forms of dystrophic epidermolysis bullosa.
SCNN1A, SCNN1B, and SCNN1G are commonly expressed in tight epithelia that have low water permeability. The major organs where ENaC is expressed include parts of the kidney tubular epithelia, the respiratory airway, the female reproductive tract, testis, including, spermatogonia in the seminiferous tubules, Sertoli cells, and spermatozoa, colon and salivary glands. In the skin, SCNN1A is expressed in the keratinocytes in the epidermal layer, in the sebaceous sweat glands, and the smooth muscle cells mostly within the cytoplasm. In contrast, in the eccrine sweat glands ENaC is mostly located on the luminal surface of eccrine duct epithelia.
Prolonged esophagitis, particularly from gastric reflux, is one factor thought to play a role in the development of Barrett's esophagus. In this condition, there is metaplasia of the lining of the lower esophagus, which changes from stratified squamous epithelia to simple columnar epithelia. Barrett's esophagus is thought to be one of the main contributors to the development of esophageal cancer.
Otoancorin is a protein found in the vertebrate inner ear, on the sensory epithelia where it connects to the gel matrix. Otoancorin is found in the cochlea, utricule, saccule, and under the cupulae on the surface of apical dells in the sensory epithelia. In humans the gene that encodes otoancorin is called OTOA. It is on chromosome 16p12.2 and contains 28 exons.
There is, however, a study of the mouse homolog that has identified high levels of expression in developing sensory epithelia so its function may be more generalized.
ENaC allows transfer of sodium ions across the epithelial cell membrane in so- called "tight-epithelia" that have low permeability. The flow of sodium ions across epithelia affects osmolarity of the extracellular fluid. Thus, ENaC plays a central role in the regulation of body fluid and electrolyte homeostasis and consequently affects blood pressure. As ENaC is strongly inhibited by amiloride, it is also referred to as an "amiloride-sensitive sodium channel".
ENaC allows transfer of sodium ions across the epithelial cell membrane in so-called "tight-epithelia" that have low permeability. The flow of sodium ions across epithelia affects osmolarity of the extracellular fluid. Thus, ENaC plays a central role in the regulation of body fluid and electrolyte homeostasis and consequently affects blood pressure. As ENaC is strongly inhibited by amiloride, it is also referred to as an "amiloride-sensitive sodium channel".
ENaC allows transfer of sodium ions across the epithelial cell membrane in so-called "tight-epithelia" that have low permeability. The flow of sodium ions across epithelia affects osmolarity of the extracellular fluid. Thus, ENaC plays a central role in the regulation of body fluid and electrolyte homeostasis and consequently affects blood pressure. As ENaC is strongly inhibited by amiloride, it is also referred to as an "amiloride-sensitive sodium channel".
ENaC allows transfer of sodium ions across the epithelial cell membrane in so-called "tight-epithelia" that have low permeability. The flow of sodium ions across epithelia affects osmolarity of the extracellular fluid. Thus, ENaC plays a central role in the regulation of body fluid and electrolyte homeostasis and consequently affects blood pressure. As ENaC is strongly inhibited by amiloride, it is also referred to as an "amiloride-sensitive sodium channel".
GPR64, together with F-actin scaffold, locates at the nonciliated principal cells of the proximal male excurrent duct epithelia, where reabsorption of testicular fluid and concentration of sperm takes place.
This makes desmosomes important in tissues that encounter high levels of mechanical stress, such as heart muscle and epithelia, and explains why it appears frequently in these types of tissues.
Ultimately, it increases the production of extracellular matrix by epithelial cells. TGF-β proteins regulate epithelia by controlling where and when they branch to form kidney, lung, and salivary gland ducts.
N-glycosyltransferases usually target adhesin proteins, which are involved in the attachment of bacterial cells to epithelia (in pathogenic bacteria); glycosylation is important for the stability and function of the adhesins.
Hair cells are the source of the most detailed understanding of mechanosensation. They are present in sensory epithelia of the inner ear and are responsible for the auditory system and vestibular system.
There are higher levels of C16orf46 expression in pancreatic adenocarcinoma tumor epithelia tissue compared to the control. There is also higher gene expression in patients with small-cell carcinoma compared to the control.
Expression of SLC16A8 is confined to the retinal pigment epithelium and choroid plexus epithelia, where it is located on the basal membrane in contrast to MCT1 which is found on the apical membrane.
In 1988, a case report used the term acquired dyskeratotic leukoplakia to refer to an acquired condition in a female where dyskeratotic cells were present in the epithelia of the mouth and genitalia.
Area composita structures consist of typical desmosomal in addition to typical fascia adhaerens proteins, whereas in epithelia both molecular classes show distinct and mutual exclusive localizations and both structures are also well separated.
In addition, spherical phases occasionally form. These may facilitate movement to new habitats. Trichoplax lacks tissues and organs; there is also no manifest body symmetry, so it is not possible to distinguish anterior from posterior or left from right. It is made up of a few thousand cells of six types in three distinct layers: dorsal epithelia cells and ventral epithelia cells, each with a single cilium ("monociliate"), ventral gland cells, syncytial fiber cells, lipophils, and crystal cells (each containing a birefringent crystal, arrayed around the rim).
Intimin is expressed on the bacterial cell surface where it can bind to its receptor Tir (Translocated intimin receptor). Tir, along with over 25 other bacterial proteins, is secreted from attaching and effacing E. coli directly into the cytoplasm of intestinal epithelial cells by a Type three secretion system. Once within the cytoplasm of the host cell, Tir is inserted into the plasma membrane, allowing surface exposure and intimin binding. Tir-intimin interaction mediates tight binding of enteropathogenic and enterohaemorrhagic E.coli to the intestinal epithelia, resulting in the formation of effacing lesions on intestinal epithelia.
The three ENaC subunits encoded by SCNN1A, SCNN1B, and SCNN1G are commonly expressed in tight epithelia that have low water permeability. The major organs where ENaC is expressed include parts of the kidney tubular epithelia, the respiratory airway, the female reproductive tract, colon, salivary and sweat glands. ENaC is also expressed in the tongue, where it has been shown to be essential for the perception of salt taste. The expression of ENaC subunit genes is regulated mainly by the mineralocorticoid hormone aldosterone that is activated by the renin-angiotensin system.
The three ENaC subunits encoded by SCNN1A, SCNN1B, and SCNN1G are commonly expressed in tight epithelia that have low water permeability. The major organs where ENaC is expressed include parts of the kidney tubular epithelia, the respiratory airway, the female reproductive tract, colon, salivary and sweat glands. ENaC is also expressed in the tongue, where it has been shown to be essential for the perception of salt taste. The expression of ENaC subunit genes is regulated mainly by the mineralocorticoid hormone aldosterone that is activated by the renin-angiotensin system.
Fluids are swept from the filtration cavity into the nephron through cilated funnels known as nephrostomes. These thin epithelial tubes are densely packed with cilia and have a distinct morphology to the other tubular epithelia of the kidney.
Enterochromaffin cells in the epithelia lining the lumen of the digestive tract secrete serotonin, while enterochromaffin-like cells at the stomach glands secrete histamine. Their synthesis, storage, and release of hormones is co-regulated by hormonal, local and nervous inputs.
EIF6 has different level of expression in different tissue and cell. EIF6 has high level of expression in stem cells and cycling cells, while it doesn't in postmitotic cells; high level in brain and epithelia, while low level in muscle.
Male and female infertility has been observed in mice mutant for GEMC1, MCIDAS, or CCNO due to defective MCC differentiation. In females, MCC loss in the oviducts is the probable cause of infertility. The efferent duct epithelia of males contains MCCs that mobilize luminal fluids to prevent the agglutination of spermatozoa and promote fluid reabsorption. In mice mutant for these genes, degeneration of Sertoli cells, thinning of the seminiferous tubule epithelia, dilation of the rete testes and seminiferous tubules, sperm agglutinations in the efferent ducts, and lack of spermatozoa in the epididymis has been observed in conjunction with defects in MCC development.
The body consists of many different types of tissue, defined as cells that act with a specialised function. The study of tissues is called histology and often occurs with a microscope. The body consists of four main types of tissues – lining cells (epithelia), connective tissue, nerve tissue and muscle tissue. Cells that lie on surfaces exposed to the outside world or gastrointestinal tract (epithelia) or internal cavities (endothelium) come in numerous shapes and forms – from single layers of flat cells, to cells with small beating hair-like cilia in the lungs, to column-like cells that line the stomach.
Epithelial cell adhesion molecule (EpCAM) is a transmembrane glycoprotein mediating Ca2+-independent homotypic cell–cell adhesion in epithelia. EpCAM is also involved in cell signaling, migration, proliferation, and differentiation. Additionally, EpCAM has oncogenic potential via its capacity to upregulate c-myc, e-fabp, and cyclins A & E. Since EpCAM is expressed exclusively in epithelia and epithelial-derived neoplasms, EpCAM can be used as diagnostic marker for various cancers. It appears to play a role in tumorigenesis and metastasis of carcinomas, so it can also act as a potential prognostic marker and as a potential target for immunotherapeutic strategies.
Hemidesmosomes form rivet-like links between cytoskeleton and extracellular matrix components such as the basal laminae that underlie epithelia. Like desmosomes, they tie to intermediate filaments in the cytoplasm, but in contrast to desmosomes, their transmembrane anchors are integrins rather than cadherins.
Starting from midgestation, the highest levels of MID1 transcript are observed in the proliferating compartments of the central nervous system and in the epithelia of the developing branchial arches, craniofacial processes, optic vesicle, in the heart and in the gastrointestinal and urogenital system.
A beetle with a scutellum, for which the shape was officially named. Epithelial cells adopt the "scutoidal shape" under certain circumstances. In epithelia, cells can 3D-pack as scutoids, facilitating tissue curvature. This is fundamental to the shaping of the organs during development.
Perifollicular erythema and scarring white patches are seen on dermoscopy. On scalp biopsy, lymphocytic and granulomatous perifolliculitis with eccentric atrophy of follicular epithelia and perifollicular fibrosis are visualized.Dhurat R, Saraogi P. Hair evaluation methods: merits and demerits. Int J Trichology. 2009;1(2):108-19.
The position of TCJ encode information about interphase cell shape anisotropy to orient division in the rounded mitotic cell. However this study is limited to only one type of epithelia in Drosophila melanogaster and has not been shown to be true in other epithelial types.
Micrograph showing Barrett's esophagus - columnar epithelia with goblet cells - on the left side of image; and normal stratified squamous epithelium on the right side of image Alcian blue stain High-magnification micrograph of Barrett's esophagus showing the characteristic goblet cells, Alcian blue stain Both macroscopic (from endoscopy) and microscopic positive findings are required to make a diagnosis. Barrett's esophagus is marked by the presence of columnar epithelia in the lower esophagus, replacing the normal squamous cell epithelium--an example of metaplasia. The secretory columnar epithelium may be more able to withstand the erosive action of the gastric secretions; however, this metaplasia confers an increased risk of adenocarcinoma.
Recent findings indicate that the keratinizing squamous epithelium of the middle ear could be subjected to human papillomavirus infection. Indeed, DNA belonging to oncogenic HPV16 has been detected in Cholesteatoma tissues, thereby underling that keratinizing squamous epithelia could potentially be a target tissue for HPV infection.
Wernerson, A. (2008). Dendrin expression in glomerulogenesis and in human minimal change nephrotic syndrome. Nephrology Dialysis Transplantation, 23(8), 2504-2511. doi: 10.1093/ndt/gfn100 Podocytes are epithelia cells in the kidneys that do not readily divide and act as a barrier that prevent urinary protein loss.
Nectins and Nectin-like molecules (Necl) are families of cellular adhesion molecules involved in Ca2+-independent cellular adhesion. Nectins are ubiquitously expressed and have adhesive roles in a wide range of tissues such as the adherens junction of epithelia or the chemical synapse of the neuronal tissue.
Weiss et al. (1993) report the preputial mucosa contains fewer Langerhans cells than most mucosal epithelia. These cells secrete cytokines (a non-antibody protein that generates an immune response on contact with specific antigens), and are an essential part of the immune system. Fleiss et al.
A major innovation was Stelzner's application of PET-CT to visualize and study the spontaneous activity of gastrointestinal sphincter systems. Other work established the existence of two separate lymphatic systems, which are located beneath the epithelia and deeply in the mesenchyme.Hansen: Prof. Dr. Dr. h.c. mult.
The point at which these two original epithelia meet is called the original squamocolumnar junction. New studies show, however, that all the cervical as well as large part of the vaginal epithelium are derived from Müllerian duct tissue and that phenotypic differences might be due to other causes.
Epithelial tissue is scutoid shaped, tightly packed and form a continuous sheet. It has almost no intercellular spaces. All epithelia is usually separated from underlying tissues by an extracellular fibrous basement membrane. The lining of the mouth, lung alveoli and kidney tubules are all made of epithelial tissue.
These hair like structures are important virulence factors for different pathogenic strains of Bacteria as they can mediate biofilm formation and adhesion to host epithelia. Other examples include Salmonella enterica serovar Typhimurium and Klebsiella pneumoniae. More generally, Lrp facilitates the proliferation and pathogenesis of bacteria in their hosts.
IL-38 is produced by mammalian cells and it binds to IL-1 receptor type I. It is expressed in basal epithelia of skin, in proliferating B cells of the tonsil, in spleen and other tissues. This cytokine is playing important role in regulation of innate and adaptive immunity.
MFGM bioactive protein components, including the glycoproteins lactadherin, MUC-1, and butyrophilin, have been shown in preclinical studies to affect immune response. These components influence the immune system by several mechanisms, including interference with microbe adhesion to intestinal epithelia, bacteriocidal action, support of beneficial microbiota, and modulation of other parts of the immune system. MFGM phospholipid components such as phosphatidylcholine are a key constituent of the intestinal mucus barrier, and therefore may contribute to intestinal defense against invasive pathogens. Sphingolipids, including sphingomyelin, are present in the apical membrane of the gut epithelia, and are also important for maintaining membrane structure, modulating growth factor receptors, and serving competitive binding inhibitors for microorganisms, microbial toxins, and viruses.
Hbl, cytotoxin K (CytK) and Nhe are all putative causes. Both Hbl and Nhe are three-component cytotoxins composed of a binding component, B, and two lytic components, L1 and L2. All three subunits act synergically to cause hemolysis. Maximal cytotoxicity of Nhe against epithelia is dependent on all three components.
This explains why coughing often occurs in those who smoke cigarettes. The body's natural reaction is to increase mucus production. In addition, mucus aids in moisturizing the inhaled air and prevents tissues such as the nasal and airway epithelia from drying out. Mucus is produced continuously, in the respiratory tract.
Adhesion molecules in endometrial epithelium: tissue integrity and embryo implantation. Journal of anatomy, 215(1), 3–13. doi:10.1111/j.1469-7580.2008.01034.x MUC16 is a transmembrane mucin expressed at the apical surface of uterine epithelia. This mucin prevents the blastocyst from implanting in an undesired located on the epithelium.
In theory, gingival fibers are the protectors against periodontitis, as once they are breached, they cannot be regenerated. When destroyed, the gingival sulcus (labelled G in the diagram) increases in depth apically, allowing more debris and bacteria to remain in intimate contact with the delicate sulcular and junctional epithelia for longer times.
This can uncover the existence of rare cell types within a cell population that may never have been seen before. For example, rare specialized cells in the lung called pulmonary ionocytes that express the Cystic Fibrosis Transmembrane Conductance Regulator were identified in 2018 by two groups performing scRNA-Seq on lung airway epithelia.
In Drosophila melanogaster, there are two types of septate junctions, smooth SJs (sSJs) and pleated SJs(pSJs). sSJs and pSJs are distributed in different tissues. sSJs are in gut endoderm and Malpighian tubules, while pSJs are in the ectodermally derived epithelia. sSJs and pSJs vary in shape but have the same function.
This can uncover the existence of rare cell types within a cell population that may never have been seen before. For example, rare specialized cells in the lung called pulmonary ionocytes that express the Cystic Fibrosis Transmembrane Conductance Regulator were identified in 2018 by two groups performing scRNA-Seq on lung airway epithelia.
The word epithelium uses the Greek roots ἐπί (epi), "on" or "upon", and θηλή (thēlē), "nipple". Epithelium is so called because the name was originally used to describe the translucent covering of small "nipples" of tissue on the lip. The word has both mass and count senses; the plural form is epithelia.
A simple columnar epithelium is a single layer of columnar cells attached to the basement membrane, with oval-shaped nuclei located in the basal region. In humans, a simple columnar epithelium lines most organs of the digestive tract including the stomach, small intestine, and large intestine. Simple columnar epithelia line the uterus.
Epithelia are polar in nature, i.e., they have an apical or mucosal side and a basolateral or serosal side. An Ussing chamber can isolate the apical side from the basolateral side. The two half chambers are filled with equal amounts of symmetrical Ringer solution to remove chemical, mechanical or electrical driving forces.
Like those of cnidarians, (jellyfish, sea anemones, etc.), ctenophores' bodies consist of a relatively thick, jelly-like mesoglea sandwiched between two epithelia, layers of cells bound by inter-cell connections and by a fibrous basement membrane that they secrete. The epithelia of ctenophores have two layers of cells rather than one, and some of the cells in the upper layer have several cilia per cell. The outer layer of the epidermis (outer skin) consists of: sensory cells; cells that secrete mucus, which protects the body; and interstitial cells, which can transform into other types of cell. In specialized parts of the body, the outer layer also contains colloblasts, found along the surface of tentacles and used in capturing prey, or cells bearing multiple large cilia, for locomotion.
This gene encodes a member of a family of candidate taste receptors that are members of the G protein-coupled receptor superfamily and that are specifically expressed by taste receptor cells of the tongue and palate epithelia. This intronless taste receptor gene encodes a 7-transmembrane receptor protein, functioning as a bitter taste receptor.
Echinaster nervous system consists of the ectoneural and the hyponeural systems. Each arm is connected to the circumoral ring and contains a radial nerve cord. The ectoneural system forms two plexus within the body, one epidermal plexus which innervates the body wall and its appendages, and one plexus which innervates the epithelia of each organ.
Agr2 is located on chromosome 7p21, a region that has frequent genetic alterations. It was first identified in estrogen receptor-positive breast cancer cells. Later studies showed elevated levels of AGR2 in adenocarcinomas of the esophagus, pancreas, and prostate. In Barrett's esophagus, Agr2 expression is elevated by over 70 times compared to normal esophageal epithelia.
Transcription factor HES-5 is a protein that in humans is encoded by the HES5 gene. HES5 regulates brain development process. HES5 expression significantly higher in squamous cervical carcinoma than in CIN as well as higher in CIN than normal cervical epithelia. Human HES5 gene binds to Notch receptor and expression of HES5 decreases during cartilage differentiation.
The two types of epithelia meet at the squamocolumnar junction. Infection with the human papillomavirus (HPV) can cause changes in the epithelium, which can lead to cancer of the cervix. Cervical cytology tests can often detect cervical cancer and its precursors, and enable early successful treatment. Ways to avoid HPV include avoiding sex, using condoms, and HPV vaccination.
Peeling Skin Syndrome 1 is caused by a genetic defect in the Corneodesmosin(CDSN) gene. This gene localizes to the human epidermis and other epithelia. The protein experiences a chain of cleavages during corneocyte maturation. Its symptoms include short stature, abnormality of metabolism/homeostasis, scaling skin, pruritus, erythema, asthma, brittle hair, and abnormality of hair texture.
In Drosophila, geranylgeranyl pyrophosphate is synthesised by HMG-CoA encoded by the Columbus gene. Geranylgeranyl pyrophosphate is utilised as a chemoattractant for migrating germ cells that have traversed the midgut epithelia. The attractant signal is produced at the gonadal precursors, directing the germ cells to these sites, where they will differentiate into ova (eggs) and spermatozoa (sperm).
Tricellular junctions seal epithelia at the corners of three cells. Due to the geometry of three-cell vertices, the sealing of the cells at these sites requires a specific junctional organization, different from those in bicellular junctions. In vertebrates, components tricellular junctions are tricellulin and lipolysis-stimulated lipoprotein receptors. In invertebrates, the components are gliotactin and anakonda.
In the brain, lesions exist in the cerebrum and cerebellum. Diseased fish typically show signs of acute meningitis, consisting of an exudate covering the brain surface. In the heart, lesions are usually signified by fibroplasias, macrophage, and lymphocyte. In kidneys, the renal tubules have hyaline droplet deposition in the epithelia and hyaline casts in the lumen.
The sensory epithelia of the inner ear are very specifically differentiated, enabling the olm to receive sound waves in the water, as well as vibrations from the ground. The complex functional- morphological orientation of the sensory cells enables the animal to register the sound sources.Bulog B. (1990). (Sense organs of the octavolateral system in proteus Proteus anguinus (Urodela, Amphibia).
MUC1 is a member of the mucin family and encodes a membrane bound, glycosylated phosphoprotein. MUC1 has a core protein mass of 120-225 kDa which increases to 250-500 kDa with glycosylation. It extends 200-500 nm beyond the surface of the cell. The protein is anchored to the apical surface of many epithelia by a transmembrane domain.
B16 cells originate in melanin-producing epithelia of mice, and are easy to track in vivo post-transplantation. Their fidelity of metastasis from skin to lung, liver, and spleen make them useful and predictable tools to study metastatic pathways.Wosko TJ, DT Ferrara, and LS Sartori. 1984. "Histological comparison of the B16 melanoma and its F1 variant".
Lactobacilli are filamentous, Gram-positive, aerotolerant bacteria, and common colonizers of the GI mucosa and squamous epithelia of mice. ASF 360 was thought to be L. acidophilus. However, 16SrRNA results showed that it is closely related to but distinct from L. acidophilus. ASF 360 is a novel lactobacillus species; clustered with L. acidophilus and L. lactis.
Pseudostratified columnar epithelium, animated image highlights the epithelial cells, goblet cells, then underlying connective tissue A pseudostratified epithelium is a type of epithelium that, though comprising only a single layer of cells, has its cell nuclei positioned in a manner suggestive of stratified epithelia. As it rarely occurs as squamous or cuboidal epithelia, it is usually considered synonymous with the term pseudostratified columnar epithelium. The term pseudostratified is derived from the appearance of this epithelium in section which conveys the erroneous (pseudo means almost or approaching) impression that there is more than one layer of cells, when in fact this is a true simple epithelium since all the cells rest on the basement membrane. The nuclei of these cells, however, are disposed at different levels, thus creating the illusion of cellular stratification.
Tufts of the glomerulus attached to the walls of the capillaries have the possibility to be collapsed or shrunk. The epithelia in the wall of the capsule are also flattened. The enlargement of the kidney can be related to the degree of cyst formation. The cysts which come from the Bowmans space can also cause the kidneys to appear asymmetrical or misshapen.
The parabasal cells include the stratum granulousum and the stratum spinosum. In these two layers, cells from the lower basal layer transition from active metabolic activity to death (apoptosis). In these mid-layers of the epithelia, the cells begin to lose their mitochondria and other cell organelles. The multiple layers of parabasal cells are polyhedral in shape with prominent nuclei.
Dr. Joseph G. Brand is a biologist currently at Monell Chemical Senses Center. In 1985, Dr. Brand discovered that the substance amiloride is an inhibitor of sodium when present in the epithelia of rats. Subsequently in 2005, Dr. Brand and Dr. Xia Li discovered that cats did not have a functioning sweet taste receptor, because it was made obsolete by evolution.
Different isoforms are located in the same individual cells, and single desmosomes contain more than one isoform of both desmocollin and desmoglein. It is unclear why there are multiple desmosomal cadherin isoforms. It is thought that they may have different adhesive properties that are required at different levels in stratified epithelia or that they have specific functions in epithelial differentiation.
Stratified columnar epithelium is a rare type of epithelial tissue composed of column shaped cells arranged in multiple layers. Stratified columnar epithelia are found in the conjunctiva of the eye, in parts of the pharynx, anus, the uterus, and the male urethra and vas deferens. It is also found in the lobar ducts in salivary glands. The cells function in secretion and protection.
The cartoon of epithelium cells connected by tricellular junctions at the regions where three cells meet. Tricellular junctions are also implicated in the regulation of cytoskeletal organization and cell divisions. In particular they ensure that cells divide according to the Hertwig rule. In some Drosophila epithelia, during cell divisions tricellular junctions establish physical contact with spindle apparatus through astral microtubules.
The Lewis antigen system is a human blood group system. It is based upon two genes on chromosome 19: FUT3, or Lewis gene; and FUT2, or Secretor gene. Both genes are expressed in glandular epithelia. FUT2 has a dominant allele which codes for an enzyme (designated Se) and a recessive allele which does not produce a functional enzyme (designated se).
Dispase is a protease which cleaves fibronectin, collagen IV, and to a lesser extent collagen I. It is found in some bacteria and can be isolated from culture filtrates of Bacillus polymyxa. It can be extracted, purified, and used in research. It can be particularly useful to separate embryonic epithelia and mesenchyme. Dispase II is specific for the cleavage of leucine- phenylalanine bonds.
Argosomes are derived from basolateral epithelial membranes and allow communication between adjacent cells. They were first described in Drosophila melanogaster, where they act as a vehicle for the spread of molecules through the epithelia of imaginal discs. Melanosomes are also transferred by filopodia from melanocytes to keratinocytes. This transfer involves a classic filopodial forming pathway, with Cdc42 and WASP as key factors.
Folia Parasitologica 35, 289–307. In natural infections, S. molnari invades the epithelia of gills and surrounding skin regions. It then forms spores in between epithelial cells,Kaup FJ, Kuhn EM, Körting W (1995) Light and electron microscopic studies on the sporogenesis of Sphaerospora molnari in the gill lamellas of carp (Cyprinus carpio). Berliner und Münchner Tierärztliche Wochenschrift 108: 206-214.
This work showed that contact inhibition of movement occurred in vivo and in 3D gels. Gary Greenburg then entered Betty' lab as a graduate student, and they started working with 48-hour chick embryos. They were able to see epithelia transform into mesenchyme when they were suspended in collagen gels. Jim Fitchett also entered the lab at about the same time.
Solitary chemosensory cells (SCCs) (also called solitary chemoreceptor cells) are isolated elements located in epithelia of the apparatuses of endodermic origin (such as respiratory and digestive apparatuses). In the aquatic vertebrates, SCCs are also present in the skin. In oral cavity, SCCs precedes the development of taste buds. For long time, SCCs were considered to be typical of aquatic vertebrates.
The proteins that form neurofilaments are members of the intermediate filament protein family, which is divided into six types based on their gene organization and protein structure. Types I and II are the keratins which are expressed in epithelia. Type III contains the proteins vimentin, desmin, peripherin and glial fibrillary acidic protein (GFAP). Type IV consists of the neurofilament proteins L, M, H and internexin.
The tissue specific expression of the δ-subunit is very different from that of the other three subunits encoded by SCNN1A, SCNN1B, and SCNN1G. While the α, β, and γ subunits are expressed mainly in the kidney tubular epithelia, the respiratory airway, the female reproductive tract, colon, salivary and sweat glands, the δ-subunit is expressed mainly in the brain, pancreas, testis and ovary.
Bartter syndrome, infantile, with sensorineural deafness (Barttin), also known as BSND, is a human gene which is associated with Bartter syndrome. This gene encodes an essential beta subunit for CLC chloride channels. These heteromeric channels localize to basolateral membranes of renal tubules and of potassium- secreting epithelia of the inner ear. Mutations in this gene have been associated with Bartter syndrome with sensorineural deafness.
The same lesions are also present in pharynx, oesophagus, and on mucus-producing epithelia of the gut, from abomasum to rectum. Zebra-striped lesions on coecum and colon are said to be typical in some cases. Rarely, also petechiae are on the rumen mucosa.Tligui, Observations nécropsiques sur les premiers cas confirmés de peste des petits ruminants au Maroc, oral presentation, El Jadida, 31-07-2008.
Simple cuboidal epithelium is a type of epithelium that consists of a single layer of cuboidal (cube-like) cells. These cuboidal cells have large, spherical and central nuclei. Simple cuboidal epithelia are found on the surface of [ ovaries], the lining of nephrons, the walls of the renal tubules, and parts of the eye and thyroid. On these surfaces, the cells perform secretion and absorption.
Intestinal glands are found in the epithelia of the small intestine, namely the duodenum, jejunum, and ileum, and in the large intestine (colon), where they are sometimes called colonic crypts. Intestinal glands of the small intestine contain a base of replicating stem cells, Paneth cells of the innate immune system, and goblet cells, which produce mucus. In the colon, crypts do not have Paneth cells.
It is highly similar to human annexins I and II sequences, each of which contain four such repeats. Exon 21 of annexin VI is alternatively spliced, giving rise to two isoforms that differ by a 6-amino acid insertion at the start of the seventh repeat. Annexin VI has been implicated in mediating the endosome aggregation and vesicle fusion in secreting epithelia during exocytosis.
The AHR is highly expressed in cells of the immune barrier organs, such as skin, lung, gut, and mucosal epithelia, as well as in the placenta. The intestinal epithelium is a relatively impermeable physical and immunological barrier. Intestinal epithelial cells participate in the inflammatory and immune responses when activated by interleukin 22 (IL-22). Innate lymphoid cells seem to be one dominant endogenous sours of IL-22.
CagA is a protein and virulence factor inserted by Helicobacter pylori into gastric epithelia. Once activated by SRC phosphorylation, CagA binds to SHP2, allosterically activating it. This leads to morphological changes, abnormal mitogenic signals and sustained activity can result in apoptosis of the host cell. Epidemiological studies have shown roles of cagA- positive H. pylori in the development of atrophic gastritis, peptic ulcer disease and gastric carcinoma.
CAR (coxsackie and adenovirus receptor) also belongs to the immunoglobulin superfamily, same like JAM proteins. CAR is expressed in the epithelia of trachea, bronchi, kidney, liver and intestine, where positively contributes to the barrier function of the tight junction. This protein mediates a neutrophil migration, cells contacts and an aggregation. It´s necessary for the embryonal heart development, especially for the organization of myofibrils in cardiomyocytes.
J Clin Chem Clin Biochem. 1989 Feb;27(2):65-74 Especially the first-time description of the storage possibility of vitamin A (retinyl ester) in organs and tissues outside the liver were new findings for the research of the vitamin A metabolism.Biesalski HK. Aspects of vitamin A metabolism in sensory epithelia (inner ear, olfactory bulbus, pineal gland).Int J Vitam Nutr Res Suppl.
An image of a lamb In sheep, enJSRVs are highly expressed in the epithelia lining different reproductive tissues, including the vagina, uterus and oviduct. The RNA of enJSRVs is first detected in the conceptus on day 12. Experiments have found that the enJSRV envelope regulates trophoblast growth and differentiation within the peri-implantation conceptus. It was discovered that enJSRVs are expressed in the trophectoderm cells of the placenta.
Several bones and cartilages make up the bony-cartilaginous framework of the nose, and the internal structure. The nose is also made up of types of soft tissue such as skin, epithelia, mucous membrane, muscles, nerves, and blood vessels. In the skin there are sebaceous glands, and in the mucous membrane there are nasal glands. The bones and cartilages provide strong protection for the internal structures of the nose.
Antibodies to CK8 (e.g. CAM 5.2) can be used to differentiate lobular carcinoma of the breast from ductal carcinoma of the breast. CAM 5.2, an antibody that reacts with an epitope found on both CK8 and CK18, is used in immunohistochemistry to demonstrate certain forms of cancer. In normal tissue, it reacts mainly with secretory epithelia, but not with squamous epithelium, such as that found in the skin, cervix, and esophagus.
Prostasin is a protein that in humans is encoded by the PRSS8 gene. This gene encodes a trypsinogen, which is a member of the trypsin family of serine proteases. This enzyme is highly expressed in prostate epithelia and is one of several proteolytic enzymes found in seminal fluid. The proprotein is cleaved to produce a light chain and a heavy chain which are associated by a disulfide bond.
Through the process of reabsorption, the majority of the fluid volume and solutes are transported from the urine to the blood. Next, secretion of materials from the renal epithelia into the urine occurs. Finally, urine as the end product travels to the ureters to be excreted. The kidneys of a common raven filter about eleven times its total body water daily, and more than 95% of the filtered water is reabsorbed.
Effects of EFF-1 and AFF-1 on vesicle morphology. EFF-AFF are the identifiers for type 1 glycoproteins that makeup cell–cell fusogens. They were first identified when EFF-1 mutants were found to "block cell fusion in all epidermal and vulval epithelia" in the roundworm, Caenorhabditis elegans. EFF-AFF is a family of type I membrane glycoproteins that act as cell–cell fusogens, named from Anchor cell fusion failure.
Metaplasia occurs when a cell of a certain type is replaced by another cell type, which may be less differentiated. It is a reversible process thought to be caused by stem cell reprogramming. Stem cells are found in epithelia and embryonic mesenchyme of connective tissue. A prominent example of metaplasia involves the changes associated with the respiratory tract in response to inhalation of irritants, such as smog or smoke.
TLR2 is expressed on microglia, Schwann cells, monocytes, macrophages, dendritic cells, polymorphonuclear leukocytes (PMNs or PMLs), B cells (B1a, MZ B, B2), and T cells, including Tregs (CD4+CD25+ regulatory T cells). In some cases, it occurs in a heterodimer (combination molecule), e.g., paired with TLR-1 or TLR-6. TLR2 is also found in the epithelia of air passages, pulmonary alveoli, renal tubules, and the Bowman's capsules in renal corpuscles.
Normal tissues consist of parenchymal cells and stromal cells. The parenchymal cells are the functional units of an organ, whereas the stromal cells provide the structure of the organ and secrete extracellular matrix as supportive, connective tissue. In normal epithelial tissues, epithelial cells, or parenchymal cells of epithelia, are highly organized, polar cells. These cells are separated from stromal cells by a basement membrane that prevents these cell populations from mixing.
Cell junctions (or intercellular bridges) are a class of cellular structures consisting of multiprotein complexes that provide contact or adhesion between neighboring cells or between a cell and the extracellular matrix in animals. They also maintain the paracellular barrier of epithelia and control paracellular transport. Cell junctions are especially abundant in epithelial tissues. Combined with cell adhesion molecules and extracellular matrix, cell junctions help hold animal cells together.
Cell junctions are especially abundant in epithelial tissues. They consist of protein complexes and provide contact between neighbouring cells, between a cell and the extracellular matrix, or they build up the paracellular barrier of epithelia and control the paracellular transport. Cell junctions are the contact points between plasma membrane and tissue cells. There are mainly 5 different types of cell junctions: tight junctions, adherens junctions, desmosomes, hemidesmosomes, and gap junctions.
This gene product belongs to the family of candidate taste receptors that are members of the G-protein-coupled receptor superfamily. These proteins are specifically expressed in the taste receptor cells of the tongue and palate epithelia. They are organized in the genome in clusters and are genetically linked to loci that influence bitter perception in mice and humans. In functional expression studies, they respond to bitter tastants.
This gene product belongs to the family of candidate taste receptors that are members of the G-protein-coupled receptor superfamily. These proteins are specifically expressed in the taste receptor cells of the tongue and palate epithelia. They are organized in the genome in clusters and are genetically linked to loci that influence bitter perception in mice and humans. In functional expression studies, they respond to bitter tastants.
This gene product belongs to the family of candidate taste receptors that are members of the G-protein-coupled receptor superfamily. These proteins are specifically expressed in the taste receptor cells of the tongue and palate epithelia. They are organized in the genome in clusters and are genetically linked to loci that influence bitter perception in mice and humans. In functional expression studies, they respond to bitter tastants.
This gene product belongs to the family of candidate taste receptors that are members of the G-protein-coupled receptor superfamily. These proteins are specifically expressed in the taste receptor cells of the tongue and palate epithelia. They are organized in the genome in clusters and are genetically linked to loci that influence bitter perception in mice and humans. In functional expression studies, they respond to bitter tastants.
This combination of roles makes microtubules important for organizing and moving intracellular constituents. The organization of microtubules in the cell is cell-type specific. In epithelia, the minus-ends of the microtubule polymer are anchored near the site of cell-cell contact and organized along the apical-basal axis. After nucleation, the minus-ends are released and then re- anchored in the periphery by factors such as ninein and PLEKHA7.
This gene product belongs to the family of candidate taste receptors that are members of the G-protein-coupled receptor superfamily. These proteins are specifically expressed in the taste receptor cells of the tongue and palate epithelia. They are organized in the genome in clusters and are genetically linked to loci that influence bitter perception in mice and humans. In functional expression studies, they respond to bitter tastants.
VPAC1 is a receptor for vasoactive intestinal peptide (VIP), a small neuropeptide. Vasoactive intestinal peptide is involved in smooth muscle relaxation, exocrine and endocrine secretion, and water and ion flux in lung and intestinal epithelia. Its actions are effected through integral membrane receptors associated with a guanine nucleotide binding protein which activates adenylate cyclase. VIP acts in an autocrine fashion via VPAC11 to inhibit megakaryocyte proliferation and induce proplatelet formation.
They also state that long term (5 years) use of creatine has been considered safe. It is important to mention that kidneys themselves, for normal physiological function, need phosphocreatine and creatine and indeed kidneys express significant amounts of creatine kinases (BB-CK and u-mtCK isoenzymes).ML.Guerrero, J.Beron, B.Spindler, P.Grosscurth, T.Wallimann and F.Verrey.Metabolic support of Na+ pump in apically permeabilized A6 kidney cell epithelia: role of creatine kinase.
Corneodesmosin is a protein that in humans is encoded by the CDSN gene. This gene encodes a protein found in corneodesmosomes, which localize to human epidermis and other cornified squamous epithelia. During maturation of the cornified layers, the protein undergoes a series of cleavages, which are thought to be required for desquamation. The gene is located in the major histocompatibility complex (MHC) class I region on chromosome 6.
If this test shows a positive result, the same casework sample will be processed further.Standard Operating Procedure of the differential extraction using a single-tube approach The first part of the differential lysis is carried out under mild conditions to gain the female DNA. Lysate of the epithelia cells is retained within the column even during heat incubation and moderate shaking. Upon centrifugation, the solution passes the column into the collection tube.
CerS5 (TRH4) mRNA is found in all tissues and is strongly expressed in muscle and brain. CerS5 is the major ceramide synthase detected in lung epithelia. Knock-down research in respiratory epithelium using CerS5 siRNA or fumonisin B1 reduced total CerS activity by 45% or 78%, respectively, indicating that CerS5 indeed contributes significantly to ceramide synthesis in lung. In the brain, CerS5 mRNA is detected in most cells within the gray and white matter tissues.
The molecule of collagen XXIII can be found either in membrane-bond form or in shed form. Type XXIII collagen is expressed in both adult tissues and developing organs. It can be found in the epidermis and other epithelia such as those in tongue, gut and lung, but also in the brain, the kidney and the cornea. It has been shown that in prostate collagen XXIII expression is associated with tumor progression.
Defensins are a family of microbicidal and cytotoxic peptides thought to be involved in host defense. They are abundant in the granules of neutrophils and also found in the epithelia of mucosal surfaces such as those of the intestine, respiratory tract, urinary tract, and vagina. Members of the defensin family are highly similar in protein sequence and distinguished by a conserved cysteine motif. Several alpha defensin genes are clustered on chromosome 8.
The two kinds of cells are the lacuna- forming cells and the epithelial cells that are typical to kidney tubules. The epithelia cells are ciliated, cylindrical, and polarized with three distinct regions. These three regions are apical, middle cytoplasmic, and basal lamina. The middle cytoplasmic region is the most active of the three due to the concentration of multiple organelles within, such as mitochondria and smooth and rough endoplasmic reticulum, among others.
In revertant mosaicism, the healthy tissue formed by mitotic recombination can outcompete the original, surrounding mutant cells in tissues such as blood and epithelia that regenerate often. In the skin disorder ichthyosis with confetti, normal skin spots appear early in life and increase in number and size over time. Other endogenous factors can also lead to mosaicism, including mobile elements, DNA polymerase slippage, and unbalanced chromosomal segregation. Exogenous factors include nicotine and UV radiation.
The parasitic stage is represented by the sessile trophont. In this phase, the protist is pear-shaped, enclosed in a cellulose wall and exhibits specific structures, rhizoids (tentacle like processes) that enable it to strictly anchor to host epithelia (gill or skin predominantly). If the infection is severe, trophonts can also be found on eyes, fins and in all oropharigeal cavity, the latter is a typical infection site in the European seabass (Dicentrarchus labrax).
PTPIP51 is a member of the RMDN protein family and localizes to the outer mitochondrial membrane, cytoplasm, and nucleus. This protein is involved in cellular differentiation, proliferation, motility, cytoskeleton formation, and apoptosis. These biological functions thus serve to facilitate mammalian development through processes such as placental villi formation and angiogenesis. In particular, it is expressed in differentiated cells and tissues, such as follicular and inter-follicular epidermis, epithelia, skeletal muscle, testis, and nervous tissue.
Specifically, mutations within the Tumor Protein 63 gene have been implicated in Hay–Wells syndrome. Residing on the long-arm of chromosome 3, the Tumor Protein 63 (TP63) gene is critical for proper development and homeostasis of stratified epithelia. In Hay–Wells syndrome, and other ectodermal dysplasia disorders, a missense, nonsense, or insertion mutation has occurred in the TP63 gene. Currently, no deletion or duplication mutations have been detected in such disorders.
Lipocalin-2 (LCN2), also known as oncogene 24p3 or neutrophil gelatinase- associated lipocalin (NGAL), is a protein that in humans is encoded by the LCN2 gene. NGAL is involved in innate immunity by sequestering iron and preventing its use by bacteria, thus limiting their growth. It is expressed in neutrophils and in low levels in the kidney, prostate, and epithelia of the respiratory and alimentary tracts. NGAL is used as a biomarker of kidney injury.
Defensins are a family of microbicidal and cytotoxic peptides thought to be involved in host defense. They are abundant in the granules of neutrophils and also found in the epithelia of mucosal surfaces such as those of the intestine, respiratory tract, urinary tract, and vagina. Members of the defensin family are highly similar in protein sequence and distinguished by a conserved cysteine motif. Several alpha defensin genes are clustered on chromosome 8.
The Ussing chamber provides a system to measure the transport of ions, nutrients, and drugs across various epithelial tissues,A guide to Ussing chamber studies of mouse intestine (Am J Physiol Gastrointest Liver Physiol. Jun 2009; 296(6): G1151–G1166. Published online Apr 2, 2009.) (although can generate false-negative results for lipophilic substances). It consists of two halves separated by the epithelia (sheet of mucosa or monolayer of epithelial cells grown on permeable supports).
Desmocollin-2 contains five N-terminal extracellular domains, a transmembrane-spanning domain, and a C-terminal cytoplasmic tail. Desmocollin-2 binds to desmoglein family members through a calcium-dependent interaction with its extracellular domains, and to plakoglobin through its cytoplasmic tail. Desmocollin-2 is ubiquitously expressed in desmosomal tissues, such as skin epithelia, and is the only desmocollin isoform expressed in human cardiac muscle, where it localizes to desmosomes within intercalated discs.
Severe aerophagia leads to accumulation of air in the gastrointestinal tract, causing the belly to be distended. It is thought that the over- expression of the SIM2 gene brings about some of the phenotypic deformities that are characteristic of Down syndrome. The presence of SIM2 mRNA in many parts of the brain known to show deformities in individuals with Down syndrome, as well as in the palate, oral and tongue epithelia, mandibular and hyoid bones.
Claudin-2 is expressed in cation-leaky epithelia such as that of the kidney proximal tubule. Mice that are deficient in claudin-2 have reduced reabsorption of Na+ in the proximal tubule, consistent with a role in paracellular transport. Similar results have been obtained with cultured cells, as overexpression in claudin-2 lacking cells leads to increase of permeability for small cations. Furthermore, claudin-2 has been shown to form paracellular channels for water.
Timing of gene expression during development varies from tissue to tissue. Basement membranes are often the driving force behind separating epithelia from stroma and connective tissue. Perlecan is of particular importance in cardiovascular, neural and cartilaginous development. Pre-implantation blastocyst development is a controlled cascade of gene regulation and intercellular signaling. Extracellular perlecan has been observed at the blastocyst stage of mouse embryonic development, specifically upregulated at the point when the embryo reaches “attachment competence”.
Cells from the lower basal layer transition from active metabolic activity to death (apoptosis). In these mid-layers of the epithelia, the cells begin to lose their mitochondria and other organelles. The cells retain a usually high level of glycogen compared to other epithelial tissue in the body. Under the influence of maternal estrogen, the vagina of a newborn is lined by thick stratified squamous epithelium (or mucosa) for two to four weeks after birth.
Melanosomes absorb the scattered light and thus diminish the photo-oxidative stress. The high perfusion of retina brings a high oxygen tension environment. The combination of light and oxygen brings oxidative stress, and RPE has many mechanisms to cope with it. # Epithelial transport: As mentioned above, RPE compose the outer blood–retinal barrier, the epithelia has tight junctions between the lateral surfaces and implies an isolation of the inner retina from the systemic influences.
TJ proteins could be divided in different groups according to their function or localization in tight junction. TJ proteins are mostly described in the epithelia and endothelia but also in myelinated cells. In the central and peripheral nervous system are TJ localized between a glia and an axon and within myelin sheaths, where they facilitate the signaling. Some of TJ proteins act as a scaffolds, that connect integral proteins with the actin in a cytoskeleton.
JSRV is transmitted by the respiratory route and may also infect lymphocytes and myeloid cells, in addition to the lung epithelia. Expression of the JSRV Envelope protein activates signalling cascades that promote cellular proliferation and malignant transformation of the cells. Initially, the tumour cells grow along the alveolar walls in a pattern reminiscent of human BAC, but subsequently become more invasive and metastasize to the local lymph nodes. Larger tumours may be necrotic and fibromatous at their centre.
In frenulates, the trophosome is limited to the post-annular portion of the trunk. While a structural variant of the frenulate trophosome seems to occur, this organ typically consists of two epithelias and blood spaces sandwiched between the basal matrix of the epithelia in which the inner one is composed of bacteriocytes and the outer one is the coelomic lining. The trophosome of Sclerolinum brattstromi consists of a centre of bacteriocytes surrounded by blood space and epithelium.
Defensin, alpha 5 (DEFA5) also known as human alpha defensin 5 (HD5) is a human protein that is encoded by the DEFA5 gene. DEFA5 is expressed in the Paneth cells of the ileum. Defensins are a family of microbicidal and cytotoxic peptides thought to be involved in host defense. They are abundant in the granules of neutrophils and also found in the epithelia of mucosal surfaces such as those of the intestine, respiratory tract, urinary tract, and vagina.
Epithelia actively pump and differentially segregate ions. In the cornea epithelium, for example, Na+ and K+ are transported inwards from tear fluid to extracellular fluid, and Cl− is transported out of the extracellular fluid into the tear fluid. The epithelial cells are connected by tight junctions, forming the major electrical resistive barrier, and thus establishing an electrical gradient across the epithelium – the transepithelial potential (TEP).Maurice, D. M. The permeability to sodium ions of the living rabbit's cornea.
This gene is an ortholog of the Drosophila fat gene, which encodes a tumor suppressor essential for controlling cell proliferation during Drosophila development. The gene product is a member of the cadherin superfamily, a group of integral membrane proteins characterized by the presence of cadherin-type repeats. This gene is expressed at high levels in a number of fetal epithelia. Transcript variants derived from alternative splicing and/or alternative promoter usage exist, but they have not been fully described.
FRAS1-related extracellular matrix protein 2 is a protein that in humans is encoded by the FREM2 gene. This gene encodes a membrane protein that belongs to the FRAS1 family. This extracellular matrix protein is thought to be required for maintaining the integrity of the skin epithelium and the differentiated state of renal epithelia. The protein localizes to the basement membrane, forming a ternary complex that plays a role in epidermal-dermal interactions during morphogenetic processes.
However supplementation with Vitamin A would be beneficial only in exceptional cases because normally the local catabolism of vitamin A will be the regulating factor. Squamous metaplasia of breast epithelia is known to be more prevalent in postmenopausal women (where it does not cause any problems at all). Staurosporine, a nonspecific protein kinase C inhibitor can induce squamous metaplasia in breast tissue while other known PKC inhibitors did not show this effect. cAMP stimulation can also induce squamous metaplasia.
A desmosome (; "binding body"), also known as a macula adherens (plural: maculae adherentes) (Latin for adhering spot), is a cell structure specialized for cell-to-cell adhesion. A type of junctional complex, they are localized spot-like adhesions randomly arranged on the lateral sides of plasma membranes. Desmosomes are one of the stronger cell-to-cell adhesion types and are found in tissue that experience intense mechanical stress, such as cardiac muscle tissue, bladder tissue, gastrointestinal mucosa, and epithelia.
NIS activity helps in the diagnosis and treatment of thyroid disease, including the highly successful treatment of thyroid cancer with radioiodide after thyroidectomy. Na-K-2Cl symporter – This specific cotransporter regulates the cell volume by controlling the water and electrolyte content within the cell. The Na-K-2Cl Cotransporter is vital in salt secretion in secretory epithelia cells along with renal salt reabsorption. Two variations of the Na-K-2Cl symporter exist and are known as NKCC1 and NKCC2.
This gene encodes a bitter taste receptor; bitter taste receptors are members of the G protein-coupled receptor superfamily and are specifically expressed by taste receptor cells of the tongue and palate epithelia. Each of these apparently intronless taste receptor genes encodes a 7-transmembrane receptor protein, functioning as a bitter taste receptor. This gene is clustered with another 3 candidate taste receptor genes on chromosome 7 and is genetically linked to loci that influence bitter perception.
In animal tissue, most cells round up to a near-spherical shape during mitosis. In epithelia and epidermis, an efficient rounding process is correlated with proper mitotic spindle alignment and subsequent correct positioning of daughter cells. Moreover, researchers have found that if rounding is heavily suppressed it may result in spindle defects, primarily pole splitting and failure to efficiently capture chromosomes. Therefore, mitotic cell rounding is thought to play a protective role in ensuring accurate mitosis.
This gene encodes a member of a family of candidate taste receptors that are members of the G protein-coupled receptor superfamily and that are specifically expressed by taste receptor cells of the tongue and palate epithelia. These apparently intronless taste receptor genes encode a 7-transmembrane receptor protein, functioning as a bitter taste receptor. This gene is clustered with another 3 candidate taste receptor genes in chromosome 7 and is genetically linked to loci that influence bitter perception.
Guanylin is a 15 amino acid polypeptide that is secreted by goblet cells in the colon. Guanylin acts as an agonist of the guanylyl cyclase receptor GC-C and regulates electrolyte and water transport in intestinal and renal epithelia. Upon receptor binding, guanylin increases the intracellular concentration of cGMP, induces chloride secretion and decreases intestinal fluid absorption, ultimately causing diarrhoea. The peptide stimulates the enzyme through the same receptor binding region as the heat-stable enterotoxins.
This gene is a member of the paired box (PAX) family of transcription factors. During mouse embryogenesis Pax9 expression starts from embryonic day 8.5 and becomes more evident by E9.5; at this stage its expression is restricted to the pharyngeal endoderm. Later on, Pax9 is also expressed in the axial skeleton. Pax9 is required for craniofacial, tooth and limb development, and may more generally involve development of stratified squamous epithelia as well as various organs and skeletal elements.
Workers in many occupations are exposed to hexavalent chromium. Problematic exposure is known to occur among workers who handle chromate-containing products and those who grind and/ or weld stainless steel. Workers who are exposed to hexavalent chromium are at increased risk of developing lung cancer, asthma, or damage to the nasal epithelia and skin. Within the European Union, the use of hexavalent chromium in electronic equipment is largely prohibited by the Restriction of Hazardous Substances Directive.
1985;27:225-45Biesalski HK, Nohr D New aspects in vitamin a metabolism: the role of retinyl esters as systemic and local sources for retinol in mucous epithelia. J Nutr. 2004 Dec;134(12 Suppl):3453S-3457S In 1995 he succeeded in demonstrating, that an alternative metabolism pathway over circulating retinyl ester exists. It was seen as a new alternative to the classical distribution method of vitamin A from the liver as retinol bound to a retinol binding protein (RBP).
Metchnikowin is a 26-residue antimicrobial peptide of the fruit fly Drosophila melanogaster that displays both antibacterial and antifungal properties. This peptide is expressed strongly in the Drosophila fat body (an organ similar to the human liver), but is also expressed at surface epithelia in the trachea and gut. This is regulated by the NF-κB signalling pathways Toll and Imd. Metchnikowin is named after Russian immunologist Élie Metchnikoff, one of the founders of modern immunology.
These have been shown to interact in a series of cell-cell and cell-matrix signaling proteins. NPHP2 has been also shown to have possible links to the function of the primary renal cilium and to control of the cell cycle (Otto). Otto further found that nephrocystin, inversin (INVS) and nephroretinin colocalize in the primary cilia of cultured renal epithelia cells. One interesting connection is that primary cilia in renal cells may perform a sensing function which maintains the renal tubules.
References: - \- Type 1: Completely ectocervical Type 2: Endocervical component but fully visible Type 3: Endocervical component, not fully visible The endocervical mucosa is about thick and lined with a single layer of columnar mucous cells. It contains numerous tubular mucous glands, which empty viscous alkaline mucus into the lumen. In contrast, the ectocervix is covered with nonkeratinized stratified squamous epithelium, which resembles the squamous epithelium lining the vagina. The junction between these two types of epithelia is called the squamocolumnar junction.
Uroguanylin is a 16 amino acid peptide that is secreted by enterochromaffin cells in the duodenum and proximal small intestine. Guanylin acts as an agonist of the guanylyl cyclase receptor guanylate cyclase 2C (GC-C), and regulates electrolyte and water transport in intestinal and renal epithelia. Its sequence is H-Asn-Asp-Asp-Cys(1)-Glu-Leu-Cys(2)-Val-Asn-Val-Ala- Cys(1)-Thr-Gly-Cys(2)-Leu-OH. In humans, the uroguanylin peptide is encoded by the GUCA2B gene.
There are no reliable tests for the diagnosis of OPA in live animals which are suitable for use on farms, so diagnosis can only be confirmed at necropsy (post-mortem examination). On necropsy, lungs are interspersed with multifocal tumors. Some of these are small discrete nodules and others will involve the entire half of a lung lobule. JSRV acutely transforms the lung epithelia into cancerous cells, with type-2 pneumocytes and club cells being the likely target for JSRV transformation.
The flight cassettes containing the newts were retrieved approximately six hours after landing. Some of the larvae were fixed and preserved for later analysis, while some were tested to estimate how space flight affected the gain of the otolith-ocular reflex and measure the otolith volumes and areas of associated sensory epithelia. Living jellyfish were counted, coded, and photographed beginning at five hours postflight. The pulse rate, numbers of arms, rhopalia, and statoliths were counted in each of the ephyrae.
Eukaryotic flagella or cilia, probably an ancestral characteristic, are widespread in almost all groups of eukaryotes, as a relatively perennial condition, or as a flagellated life cycle stage (e.g., zoids, gametes, zoospores, which may be produced continually or not). The first situation is found either in specialized cells of multicellular organisms (e.g., the choanocytes of sponges, or the ciliated epithelia of metazoans), as in ciliates and many eukaryotes with a "flagellate condition" (or "monadoid level of organization", see Flagellata, an artificial group).
The somatosensory system is a complex sensory system made up of a number of different receptors, including thermoreceptors, nociceptors, mechanoreceptors and chemoreceptors. It also comprises essential processing centres, or sensory modalities, such as proprioception, touch, temperature, and nociception. The sensory receptors cover the skin and epithelia, skeletal muscles, bones and joints, internal organs, and the cardiovascular system. While touch (also called tactile or tactual perception) is considered one of the five traditional senses, the impression of touch is formed from several modalities.
In a study using non-small cell lung cancers (NSCLC), c-jun was found to be overexpressed in 31% of the cases in primary and metastatic lung tumors, whereas normal conducting airway and alveolar epithelia in general did not express c-jun. A study with a group consisted of 103 cases of phase I/II invasive breast cancers showed that activated c-jun is expressed predominantly at the invasive front of breast cancer and is associated with proliferation and angiogenesis.
The glycocalyx, also known as the pericellular matrix, is a glycoprotein and glycolipid covering that surrounds the cell membranes of some bacteria, epithelia, and other cells. In 1970, Martinez and Palomo discovered the cell coat in animal cells, which is known as the glycocalyx. Most animal epithelial cells have a fuzz-like coating on the external surface of their plasma membranes. This coating consists of several carbohydrate moieties of membrane glycolipids and glycoproteins, which serve as backbone molecules for support.
A stratified squamous epithelium consists of squamous (flattened) epithelial cells arranged in layers upon a basal membrane. Only one layer is in contact with the basement membrane; the other layers adhere to one another to maintain structural integrity. Although this epithelium is referred to as squamous, many cells within the layers may not be flattened; this is due to the convention of naming epithelia according to the cell type at the surface. In the deeper layers, the cells may be columnar or cuboidal.
A simple squamous epithelium is a single layer of flat cells in contact with the basal lamina (one of the two layers of the basement membrane) of the epithelium. This type of epithelium is often permeable and occurs where small molecules need to pass quickly through membranes via filtration or diffusion. Simple squamous epithelia are found in capillaries, alveoli, glomeruli, and other tissues where rapid diffusion is required.AAMC - 2015 MCAT Question Pack Explanations Cells are flat with flattened and oblong nuclei.
The Belgian Draft Horse is one breed in which JEB occurs Junctional epidermolysis bullosa (JEB) is an inherited disorder that is also known as red foot disease or hairless foal syndrome. JEB is the result of a genetic mutation that inhibits protein production that is essential for skin adhesion. Therefore, tissues, such as skin and mouth epithelia, are affected. Blisters form over the entire body causing pain and discomfort,and open sores leave newborn foals highly susceptible to secondary infection.
This gene product belongs to the family of candidate taste receptors that are members of the G-protein-coupled receptor superfamily. These proteins are specifically expressed in the taste receptor cells of the tongue and palate epithelia. They are organized in the genome in clusters and are genetically linked to loci that influence bitter perception in mice and humans. In functional expression studies, TAS2R14 responds to (−)-α-thujone, the primary neurotoxic agent in absinthe, and picrotoxin, a poison found in fishberries.
Several theories have been posited on how the defects in the protein and cellular function cause the clinical effects. The most current theory suggests that defective ion transport leads to dehydration in the airway epithelia, thickening mucus. In airway epithelial cells, the cilia exist in between the cell's apical surface and mucus in a layer known as airway surface liquid (ASL). The flow of ions from the cell and into this layer is determined by ion channels such as CFTR.
The apical membranes of the dark cells also have a K+ channel which is formed of two subunits, the KCNE1 regulatory protein and the KCNQ1 channel proteins.[8] This channel provides the pathway through which K+ is secreted into the endolymph. As a result, mutations in the KCNE1 gene disrupt endolymph production in the vestibular system, leading to the collapse of the epithelia of the roof of the utricle, saccule and ampullae, as well as dysfunction of the vestibular sensory organs.
The synergistic transcriptional activation requires both interactions at multiple protein-protein interfaces and protein-DNA interactions. This indicates that one mechanism of NKX3-1 dependent transcriptional activation in prostate epithelia requires combinatorial interactions with other factors expressed within those cells In 2000, full length NKX3-1 cDNA was obtained from a human prostate cDNA library. Korkmaz et al. identified 3 splice variants with deletions in the N-terminal region as well as a variant at position 137 within the homeobox domain.
Keratomalacia is an eye disorder that results from vitamin A deficiency. Vitamin A is required to maintain specialized epithelia (such as in the cornea and conjunctiva). The precise mechanism is still not known, but vitamin A is necessary for the maintenance of the specialized epithelial surfaces of the body. A lack of vitamin A leads to atrophic changes in the normal mucosal surface, with loss of goblet cells, and replacement of the normal epithelium by an inappropriate keratinized stratified squamous epithelium.
Thus they express the intermediate filament protein vimentin, a feature used as a marker to distinguish their mesodermal origin. However, this test is not specific as epithelial cells cultured in vitro on adherent substratum may also express vimentin after some time. In certain situations, epithelial cells can give rise to fibroblasts, a process called epithelial- mesenchymal transition (EMT). Conversely, fibroblasts in some situations may give rise to epithelia by undergoing a mesenchymal to epithelial transition (MET) and organizing into a condensed, polarized, laterally connected true epithelial sheet.
Figure 3: Variety of perfusion culture containers for insertion of Minusheet tissue carriers. Each of the perfusion culture containers has at least one inlet and one outlet for the transport of culture medium. A basic version of a container allows the simple bathing of cells respectively growing tissues under continuous medium transport (Fig. 4a). In a gradient container the tissue carrier is placed between the base and the lid so that both sides can be provided with individual media mimicking a typical environment for epithelia (Fig. 4b).
However, it also reacts with a range of malignant cells, including those derived from secretory epithelia, but also some squamous carcinomata, such as spindle cell carcinoma. It is considered useful in identifying microscopic metastases of breast carcinoma in lymph nodes, and in distinguishing Paget's disease from malignant melanoma. It also reacts with neuroendocrine tumors. Keratin 8 is often used together with keratin 18 and keratin 19 to differentiate cells of epithelial origin from hematopoietic cells in tests that enumerate circulating tumor cells in blood.
P2X purinoceptor 4 is a protein that in humans is encoded by the P2RX4 gene. The product of this gene belongs to the family of purinoceptors for ATP. Multiple alternatively spliced transcript variants have been identified for this gene although their full-length natures have not been determined. The receptor is found in the central and peripheral nervous systems, in the epithelia of ducted glands and airways, in the smooth muscle of the bladder, gastrointestinal tract, uterus, and arteries, in uterine endometrium, and in fat cells.
This diffuse over-expression in the tumour cells provides a diagnostic marker for HPV involvement. Although HPV E6 and E7 reduce tumour suppressor activity, they do so less than genetic and epigenetic processes do in HPV-OPC. The tonsillar epithelia (palatine and lingual) share similar nonkeratinization characteristics with the cervix, where HPV infection plays the major role in cases of cervical cancer. Also E6 and E7 may make HPV+OPC more immunogenic than HPV-OPC, since anti-E6 and E7 antibodies may be detected in these patients.
Papillomaviruses replicate exclusively in keratinocytes. Keratinocytes form the outermost layers of the skin, as well as some mucosal surfaces, such as the inside of the cheek or the walls of the vagina. These surface tissues, which are known as stratified squamous epithelia, are composed of stacked layers of flattened cells. The cell layers are formed through a process known as cellular differentiation, in which keratinocytes gradually become specialized, eventually forming a hard, crosslinked surface that prevents moisture loss and acts as a barrier against pathogens.
In human cells, the ABO alleles and their encoded glycosyltransferases have been described in several oncologic conditions. Using anti-GTA/GTB monoclonal antibodies, it was demonstrated that a loss of these enzymes was correlated to malignant bladder and oral epithelia. Furthermore, the expression of ABO blood group antigens in normal human tissues is dependent the type of differentiation of the epithelium. In most human carcinomas, including oral carcinoma, a significant event as part of the underlying mechanism is decreased expression of the A and B antigens.
In human cells, the ABO alleles and their encoded glycosyltransferases have been described in several oncologic conditions. Using anti-GTA/GTB monoclonal antibodies, it was demonstrated that a loss of these enzymes was correlated to malignant bladder and oral epithelia. Furthermore, the expression of ABO blood group antigens in normal human tissues is dependent the type of differentiation of the epithelium. In most human carcinomas, including oral carcinoma, a significant event as part of the underlying mechanism is decreased expression of the A and B antigens.
It is capable of producing multiple alternatively spliced transcripts. The largest known transcript encodes fibrocystin /polyductin (FPC), which is a large receptor-like integral membrane protein of 4074 amino acids. The structure of the FPC consist of a single transmembrane, a large N-terminal extracellular region, and a short intracellular cytoplasmic domain. The FPC protein is found on the primary cilia of epithelia cells of cortical and medullary collecting ducts and cholangiocytes of bile ducts, and show similarity to polycystins and several other ciliopathy proteins.
This is achieved through the action of the Na+/K+ pump, the energy for which is provided through the hydrolysis of ATP. Three Na+ ions are extruded from the cell in exchange for two K+ ions entering through the intramembrane enzyme Na+/K+-ATPase; this leaves a relative deficiency of Na+ in the intracellular compartment. Na+ ions diffuse down their concentration gradient into the columnar epithelia, co- transporting glucose. Once inside the epithelial cells, glucose reenters the bloodstream through facilitated diffusion through GLUT2 transporters.
However, the epithelia of the mouth also has a high turnover rate and makes oral ulceration (mucositis) a common side effect of chemotherapy. Erosions, which involve the epithelial layer, are red in appearance since the underlying lamina propria shows through. When the full thickness of the epithelium is penetrated (ulceration), the lesion becomes covered with a fibrinous exudate and takes on a yellow-grey color. Because an ulcer is a breach of the normal lining, when seen in cross section, the lesion is a crater.
On the other hand, the various subsets are also part of the innate immune system, as restricted TCR or NK receptors may be used as pattern recognition receptors. For example, large numbers of human Vγ9/Vδ2 T cells respond within hours to common molecules produced by microbes, and highly restricted Vδ1+ T cells in epithelia respond to stressed epithelial cells. An antibody is made up of two heavy chains and two light chains. The unique variable region allows an antibody to recognize its matching antigen.
The LECT2 protein consists of 133`amino acids Its structure is similar to that of the M23 family of metalloendopeptidases. Unlike this family of peptidases, however, LECT2 has not been found to possess enzymatic activity and does not appear to share any functions with M23 metalloendopeptidases. It is widely expressed in vascular tissues, smooth muscle cells, adipocytes, cerebral neurons, apical squamous epithelia, parathyroid tissues, the epithelial cells of sweat and sebaceous glands, Hassall bodies, and monocytes. The liver hepatocyte is considered to be the source of the LECT2 circulating in blood.
AGK expression has also been correlated with certain cancer phenotypes. AGK expression, in coordination with AGX, was not detected in non-neoplastic epithelia, while both were weakly expressed in the majority of high-grade intra-epithelial neoplasia (HG-PIN). Expressions of both enzymes were significantly correlated with primary Gleason grade of cancer foci and capsular invasion. Overexpression of AGK sustains constitutive JAK2/STAT3 activation, consequently promoting the cancer stem cell population and augmenting the tumorigenicity of esophageal squamous cell carcinoma (ESCC) cells both in vivo and in vitro.
CaMKII gamma holoenzyme in its (A) closed and the (B) open conformations /calmodulin-dependent protein kinase II (CaM kinase II or CaMKII) is a serine/threonine-specific protein kinase that is regulated by the /calmodulin complex. CaMKII is involved in many signaling cascades and is thought to be an important mediator of learning and memory. CaMKII is also necessary for homeostasis and reuptake in cardiomyocytes, chloride transport in epithelia, positive T-cell selection, and CD8 T-cell activation. Misregulation of CaMKII is linked to Alzheimer’s disease, Angelman syndrome, and heart arrhythmia.
The human vomeronasal organ has epithelia that may be able to serve as a chemical sensory organ; however, the genes that encode the VNO receptors are nonfunctional pseudogenes in humans. Also, while there are sensory neurons in the human VNO there seem to be no connections between the VNO and the central nervous system. The associated olfactory bulb is present in the fetus, but regresses and vanishes in the adult brain. There have been some reports that the human VNO does function, but only responds to hormones in a "sex-specific manner".
Balasubramanian is now working on stem cell biology and its use in restoring lost vision. He and his group have been successful in isolating the adult stem cells found in the limbus, around the cornea, and culturing them on human amniotic membrane. These cultured stem cells were, later, used to produce corneal epithelia that can be stitched on to human eye. Clinical tests on 200 patients who lost eyesight due to chemical or fire burns returned significantly good results with vision restoration to 20/20 levels, with or without subsequent corneal grafts or transplantation.
LECT2 protein is widely expressed in vascular tissues, smooth muscle cells, adipocytes, cerebral neurons, apical squamous epithelia, parathyroid tissues, the epithelial cells of sweat and sebaceous glands, Hassall bodies, and monocytes. When these cells or tissues are subjected to inflammatory, fibrotic, and other insults, they commonly reduce their expression of LECT2. The liver hepatocyte is considered to be the source of the LECT2 circulating in blood. However, its expression in these cells is extremely low or undetectable even though these cells express very high levels of LECT2 mRNA.
Found in vertebrate epithelia, tight junctions act as barriers that regulate the movement of water and solutes between epithelial layers. Tight junctions are classified as a paracellular barrier which is defined as not having directional discrimination; however, movement of the solute is largely dependent upon size and charge. There is evidence to suggest that the structures in which solutes pass through are somewhat like pores. Physiological pH plays a part in the selectivity of solutes passing through tight junctions with most tight junctions being slightly selective for cations.
In addition, novel bacterial products (surfactants from Pseudomonas) can directly kill the external stages of the parasite without harming the host. Ichtyophthirius multifiliis inflicts considerable damage to gills and skin in two ways. Firstly, the theronts penetrate the host epithelia and, when the number of parasites is high in relation to the fish size, the penetration may directly kill the fish by destroying the integrity of the fish surface. Secondly, if the invasion is successful, the invading theronts transform into the trophont stage in the fish epidermis where they develop and expand their volume manifold.
Subsequently, it was found to be a cell–cell adhesion molecule detected on leukocytes, epithelia, and endothelia. The encoded protein mediates cell adhesion via homophilic as well as heterophilic binding to other proteins of the subgroup. Multiple cellular activities have been attributed to the encoded protein, including roles in the differentiation and arrangement of tissue three-dimensional structure, angiogenesis, apoptosis, tumor suppression, metastasis, and the modulation of innate and adaptive immune responses. Multiple transcript variants encoding different isoforms have been reported, but the full-length nature of only two has been determined.
This gene encodes a protein that belongs to the pi3/pi4-kinase family of proteins. The gene product is an enzyme that phosphorylates phosphoinositides on the 3-hydroxyl group of the inositol ring. It is an important modulator of extracellular signals, including those elicited by E-cadherin-mediated cell- cell adhesion, which plays an important role in maintenance of the structural and functional integrity of epithelia. In addition to its role in promoting assembly of adherens junctions, the protein is thought to play a pivotal role in the regulation of cytotoxicity in NK cells.
Elizabeth Dexter “Betty” Hay (April 2, 1927 – August 20, 2007) was an American cell and developmental biologist. She was best known for her research in limb regeneration, the role of the extracellular matrix (ECM) in cell differentiation, and epithelial-mesenchymal transitions (EMT). Hay led many research teams in discovering new findings in these related fields, which led her to obtain several high honors and awards for her work. Hay primarily worked with amphibians during her years of limb regeneration work and then moved onto avian epithelia for research on the ECM and EMT.
These results are consistent with FOXO4 providing a role in inhibiting the epithelia to mesenchymal transition (EMT). In non-small cell lung carcinoma, there are varying levels of FOXO4 expressed that correspond to how the cancer was staged; worse cases had the lowest amount of FOXO4 while less severe cases had higher levels of FOXO4. As with gastric cancer, these cancers with the lowest levels of FOXO4 also had the lowest levels of E-cadherin and highest levels of vimentin, consistent with FOXO4 acting as a suppressor of the EMT phenotype.
In the rat embryo, perlecan expression has been shown to increase in vascular smooth muscle cells (VSMCs) post e19 in fetal development. This correlates perfectly with the ceasing of proliferation of VSMCs at e18 and a change in their phenotype. The theory put forward in this study is that perlecan plays an anti-proliferative role for VSMCs once a certain developmental point is reached, much like confluence-dependent expression of perlecan in culture. These findings were corroborated by similar results from studies of rat pulmonary artery and lung epithelia.
Intercalated discs consist of three different types of cell-cell junctions: the actin filament anchoring adherens junctions, the intermediate filament anchoring desmosomes, and gap junctions. They allow action potentials to spread between cardiac cells by permitting the passage of ions between cells, producing depolarization of the heart muscle. However, novel molecular biological and comprehensive studies unequivocally showed that intercalated discs predominantly consist of mixed-type adhering junctions named area composita (pl. areae Compositae) representing an amalgamation of typical desmosomal and fascia adhaerens proteins (in contrast to various epithelia).
PCFT is expressed at the sinusoidal (basolateral) membrane of the hepatocyte, the apical brush- border membrane of the proximal tubule of the kidney, the basolateral membrane of the retinal pigment epithelium and the placenta. There is a prominent low- pH folate transport activity in the cells and/or membrane vesicles derived from these tissues which, in some cases, has been shown to be indicative of a proton-coupled folate transport process. However, it is unclear as to the extent that PCFT contributes to folate transport across these epithelia.
Three species of bacteria, Carnobacterium pleistocenium, Chryseobacterium greenlandensis, and Herminiimonas glaciei, have reportedly been revived after surviving for thousands of years frozen in ice. Certain bacteria, notably Pseudomonas syringae, produce specialized proteins that serve as potent ice nucleators, which they use to force ice formation on the surface of various fruits and plants at about −2 °C. The freezing causes injuries in the epithelia and makes the nutrients in the underlying plant tissues available to the bacteria. Listeria grows slowly in temperatures as low as -1.5 °C and persists for some time in frozen foods.
ILC2s play the crucial role of secreting type 2 cytokines in response to large extracellular parasites. They express characteristic surface markers and receptors for chemokines, which are involved in distribution of lymphoid cells to specific organ sites. They require IL-7 for their development, which activates two transcription factors (both required by these cells)—RORα and GATA3. After stimulation with Th2 polarising cytokines, which are secreted mainly by epithelia (e.g. IL-25, IL-33, TSLP, prostaglandin D2 and leukotriene D4), ILC2s begin to produce IL-5, IL-13, IL-9, IL-4 rapidly.
PMP22/gas-3, called peripheral myelin protein, is located in the myelin sheath. The expression of this protein is associated with a differentiation of Schwann cells, an establishment of tight junction in the Schwamm cell membrane or a compact formation of myelin. It is also present in epithelial cells of lungs and intestine, where interacts with occludin and ZO-1, that together create the TJ in the epithelia. PMP22/gas-3 belongs to the epithelial membrane protein family (EMP1-3), which conducts a growth and differentiation of cells.
The object was first described by Gómez-Gálvez et al. in a paper entitled Scutoids are a geometrical solution to three-dimensional packing of epithelia, and published in July 2018. Officially, the name scutoid was coined because of its resemblance to the shape of the scutum and scutellum in some insects, such as beetles in the subfamily Cetoniinae. Unofficially, Clara Grima has stated that while working on the project, the shape was temporarily called an Escu-toid as a joke after the biology group leader Luis M. Escudero.
Model of the AMP drosomycin Drosomycin is an antifungal peptide from Drosophila melanogaster and was the first antifungal peptide isolated from insects. Drosomycin is induced by infection by the Toll signalling pathway, while expression in surface epithelia like the respiratory tract is instead controlled by the immune deficiency pathway (Imd). This means that drosomycin, alongside other antimicrobial peptides (AMPs) such as cecropins, diptericin, drosocin, metchnikowin and attacin, serves as a first line defence upon septic injury. However drosomycin is also expressed constitutively to a lesser extent in different tissues and throughout development.
Comparing distinctions between immune cells’ overall transcriptional program can generate plots that position each cell type to best reflect its expression profile relative to all other cells and can reveal interesting relationships between cell types. For example, the transcriptional profiles from thymic medullary epithelial immune cells mapped closer to lymphocytes than to other epithelia. This can suggest that a functional interaction exists between these two cells type and requires the sharing of particular transcripts and proteins. When comparing gene expression profiles from cells of the blood system, T-cell and B-cell subsets tightly group with their respective cell types.
Pseudomonas syringae—more than any mineral or other organism—is responsible for the surface frost damage in plants exposed to the environment. For plants without antifreeze proteins, frost damage usually occurs between -4 and -12 °C as the water in plant tissue can remain in a supercooled liquid state. P. syringae can cause water to freeze at temperatures as high as −1.8 °C (28.8 °F), but strains causing ice nucleation at lower temperatures (down to −8 °C) are more common. The freezing causes injuries in the epithelia and makes the nutrients in the underlying plant tissues available to the bacteria.
The iris dilator muscle is strictly attached to the anterior side of the iris pigmented epithelium and represents the anterior continuation of the pigmented ciliary epithelium. The ciliary epithelia represent the anterior continuation of the multilayered retina, whose retinal pigmented epithelium (RPE) corresponds to the pigmented ciliary epithelium, while the multilayered sensory retina fades into the non-pigmented ciliary epithelium. Despite their very different functions and histological appearances, these regions have a common origin from the two layers of the embryological optic cup. The melanosomes of the IPE are distinctive, being larger, blacker and rounder than those in the ciliary epithelium or RPE.
It may or may not be a precancerous indication associated with later malignancy, but the level of appropriate concern is highly dependent on the context with which it is diagnosed. For example, already differentiated, specialised cells such as epithelia displaying "cellular atypia" are far less likely to become problematic [cancerous/ malignant] than are myeloid progenitor cells of the immune system. The 'further back' in an already specialised, differentiated cell's lineage, the more problematic cellular atypia is likely to be. This is due to the conferring of such atypia to progeny-cells further down the lineage of that cell type.
SMOLD usually affects multiple ducts and frequently (relative to extremely low absolute prevalence) both breasts hence it is very likely that systemic changes such as hormonal interactions are involved. At least the following factors have been considered in the aetiology of SMOLD: reactive change to chronic inflammation, systemic hormonal changes, smoking, dysregulation in beta-catenin expression, changes in retinoic acid and vitamin D metabolism or expression. Vitamin A deficiency may cause epidermilization of the ducts and squamous metaplasia and likely also contributes to infection. Vitamin A deficiency has been observed to cause squamous metaplasia in many types of epithelia.
The different families of stretch-activated ion channels are responsible for different functions around the body. The DEG/ENaC family consists of two subgroups: the ENaC subfamily regulates Na+ reabsorption in kidney and lung epithelia; the ASIC subfamily is involved in fear conditioning, memory formation, and pain sensation. The TRP superfamily of channels are found in sensory receptor cells that are involved in heat sensation, taste, smell, touch, and osmotic and volume regulation. MscM, MscS, and MscL channels (mechanosensitive channels of mini, small, and large conductance) regulate osmotic pressure in cells by releasing intracellular fluid when they become too stretched.
In molecular biology, the electroneutral cation-Cl (electroneutral potassium chloride cotransporter) family of proteins are a family of solute carrier proteins. This family includes the products of the Human genes: SLC12A1, SLC12A1, SLC12A2, SLC12A3, SLC12A4, SLC12A5, SLC12A6, SLC12A7, SLC12A8 and SLC12A9. The K-Cl co-transporter (KCC) mediates the coupled movement of K+ and Cl− ions across the plasma membrane of many animal cells. This transport is involved in the regulatory volume decrease in response to cell swelling in red blood cells, and has been proposed to play a role in the vectorial movement of Cl− across kidney epithelia.
The identity of the molecules on the trophoblast and the endometrial epithelia that mediate the initial interaction between the two remain unidentified. However, a number of research groups have proposed that MUC1, a member of the Mucin family of glycosylated proteins, is involved. MUC1 is a transmembrane glycoprotein expressed at the apical surface of endometrial epithelial cells during the window of implantation in humans and has been shown to be differentially expressed between fertile and infertile subjects during this time. MUC1 displays carbohydrate moieties on its extracellular domain that are ligands of L-selectin, a protein expressed on the surface of trophoblast cells.
According to one hypothesis, during its passage through the nasal ducts, the water would have been 'smelled' by olfactory epithelia. However, more to the rear a second pair of openings is present in the palate; a later hypothesis holds that these are the real choanae and the front pair in reality represented paired salt glands. The distance between the eye sockets and the nostrils was so limited because the nasal bones were strongly reduced, with many species even absent. The premaxillae directly touched the frontal bones, with the elasmosaurids even reaching backwards to the parietal bones.
It penetrates gill epithelia, skin and fins of the fish host and resides as a feeding stage (the trophont) inside the epidermis. It is visible as a white spot on the surface of the fish but, due to its internal microhabitat, it is a true endoparasite and not an ectoparasite. It causes a disease commonly referred to as white spot disease due to the macroscopically visible trophonts (up to 1 mm in diameter) in the skin and fins. The trophont, continuously rotating, is surrounded by host cells (epidermal cells and leukocytes), producing a minute elevation of the skin.
ENaC is located in the apical membrane of polarized epithelial cells in particular in the kidney (primarily in the collecting tubule), the lung, the skin, the male and female reproductive tracts and the colon. Epithelial sodium channels facilitate Na⁺ reabsorption across the apical membranes of epithelia in the distal nephron, respiratory and reproductive tracts and exocrine glands. Since Na⁺ ion concentration is a major determinant of extracellular fluid osmolarity, changes in Na⁺ concentration affect the movement of fluids and consequently fluid volume and blood pressure. The activity of ENaC in the colon and kidney is modulated by the mineralcorticoid aldosterone.
Hence, in these epithelia with motile cilia, ENaC functions as a regulator of the osmolarity of the periciliary fluid, and its function is essential to maintain fluid volume at a depth necessary for the motility of the cilia. In the respiratory tract this movement is essential for clearing mucosal surface, and in the female reproductive tract, motility of the cilia is essential for the movement of oocytes. In contrast to ENaC, CFTR that regulates chloride ion transport is not found on cilia. These findings contradict a previous hypothesis that ENaC is downregulated by direct interaction with CFTR.
EP3 is widely distributed in humans. Its protein and/or mRNA is expressed in kidney (i.e. glomeruli, Tamm-Horsfall protein negative late distal convoluted tubules, connecting segments, cortical and medullary collecting ducts, media and endothelial cells of arteries and arterioles); stomach (vascular smooth muscle and gastric fundus mucosal cells); thalamus (anterior, ventromedial, laterodorsal, paraventricular and central medial nuclei); intestinal mucosal epithelia at the apex of crypts; myometrium (stromal cells, endothelial cells, and, in pregnancy, placenta, chorion, and amnion); mouth gingival fibroblasts; and eye (corneal endothelium and keratocytes, trabecular cells, ciliary epithelium, and conjunctival and iridal stroma cells, and retinal Müller cells).
Several types of catenins work with N-cadherins to play an important role in learning and memory (For full article, see Cadherin- catenin complex in learning and memory). Cell-cell adhesion complexes are required for simple epithelia in higher organisms to maintain structure, function and polarity. These complexes, which help regulate cell growth in addition to creating and maintaining epithelial layers, are known as adherens junctions and they typically include at least cadherin, β-catenin, and α-catenin. Catenins play roles in cellular organization and polarity long before the development and incorporation of Wnt signaling pathways and cadherins.
Involucrin is a highly reactive, soluble, transglutaminase substrate protein present in keratinocytes of epidermis and other stratified squamous epithelia. It first appears in the cell cytosol, but ultimately becomes cross-linked to membrane proteins by transglutaminase thus helping in the formation of an insoluble envelope beneath the plasma membrane functioning as a glutamyl donor during assembly of the cornified envelope. Involucrin is synthesised in the stratum spinosum and cross linked in the stratum granulosum by the transglutaminase enzyme that makes it highly stable. Thus it provides structural support to the cell, thereby allowing the cell to resist invasion by micro-organisms.
It has been speculated that since EpCAM in normal epithelia is expressed mostly on the basolateral membrane, it would be much less accessible to antibodies than EpCAM in cancer tissue, where it is homogeneously distributed on the cancer cell surface. In addition to being overexpressed in many carcinomas, EpCAM is expressed in cancer stem cells, making EpCAM an attractive target for immunotherapy. However, the heterogeneous expression of EpCAM in carcinomas and the fact that EpCAM is not tumor-specific (i.e., it is found in normal epithelium) raise concerns that immunotherapy directed towards EpCAM could have severe side effects.
Matriptase is an epithelial-derived, integral membrane serine protease. This protease forms a complex with the Kunitz-type serine protease inhibitor, HAI-1, and is found to be activated by sphingosine-1-phosphate. This protease has been shown to cleave and activate hepatocyte growth factor/scatter factor, and urokinase plasminogen activator, which suggest the function of this protease as an epithelial membrane activator for other proteases and latent growth factors. Matriptase is a type II transmembrane serine protease expressed in most human epithelia, where it is coexpressed with its cognate transmembrane inhibitor, hepatocyte growth factor activator inhibitor (HAI)-1.
Tight junctions represent one mode of cell-to-cell adhesion in epithelial or endothelial cell sheets, forming continuous seals around cells and serving as a physical barrier to prevent solutes and water from passing freely through the paracellular space. The protein encoded by this immunoglobulin superfamily gene member is an important regulator of tight junction assembly in epithelia. In addition, the encoded protein can act as (1) a receptor for reovirus, (2) a ligand for the integrin LFA1, involved in leukocyte transmigration, and (3) a platelet receptor. Multiple transcript variants encoding two different isoforms have been found for this gene.
The cells lining the urethra (the epithelium) start off as transitional cells as it exits the bladder, which are variable layers of flat to cuboidal cells that change shape depending on whether they are compressed by the contents of the urethra. Further along the urethra there are pseudostratified columnar and stratified columnar epithelia. The lining becomes multiple layers of flat cells near the end of the urethra, which is the same as the external skin around it. There are small mucus-secreting urethral glands, as well as bulbo- urethral glands of Cowper, that secret mucous acting to lubricate the urethra.
The somatosensory system comprises a diverse range of receptors and processing centers to produce the perception of touch, temperature, proprioception, and nociception. Receptors are located throughout the body including the skin, epithelia, internal organs, skeletal muscles, bones, and joints. The cutaneous receptors of the skin project in an orderly fashion to the spinal cord, and from there, via different afferent pathways (dorsal column-medial lemniscus tract and spinothalamic tract), to the ventral posterior nucleus of the thalamus and the primary somatosensory cortex. Again, adjacent areas on the skin are represented by adjacent neurons in all aforementioned structures.
Although disjointed and scattered when they have to cover a large space, fibroblasts, when crowded, often locally align in parallel clusters. Unlike the epithelial cells lining the body structures, fibroblasts do not form flat monolayers and are not restricted by a polarizing attachment to a basal lamina on one side, although they may contribute to basal lamina components in some situations (e.g. subepithelial myofibroblasts in intestine may secrete the α-2 chain-carrying component of the laminin, which is absent only in regions of follicle-associated epithelia which lack the myofibroblast lining). Fibroblasts can also migrate slowly over substratum as individual cells, again in contrast to epithelial cells.
Suply T, Hannedouche S, Carte N, Li J, Grosshans B, Schaefer M, Raad L, Beck V, Vidal S, Hiou-Feige A, Beluch N, Barbieri S, Wirsching J, Lageyre N, Hillger F, Debon C, Dawson J, Smith P, Lannoy V, Detheux M, Bitsch F, Falchetto R, Bouwmeester T, Porter J, Baumgarten B, Mansfield K, Carballido JM, Seuwen K and Bassilana F. (2017). A natural ligand for the orphan receptor GPR15 modulates lymphocyte recruitment to epithelia. Sci Signal 10.28900043 The second ligand is a fragment of thrombomodulin exerting anti-inflammatory function in mice. Clinical significance Human GPR15 was originally cloned as a co-receptor for HIV or the simian immunodeficiency virus.
Immunologically detected ALOXE3 and ALOX12B in humans and Aloxe3 and Alox12b in mice have a similar tissue distribution in being highly expressed in the outer, differentiated layers of the epidermis; they co-localize at the surface of keratinocytes in the stratum granulosum of mouse skin and during mouse embryogenesis appear concurrently at the onset of skin development at day 15.5. ALOXE3 mRNA in humans was also detected at low levels in the pancreas, ovary, brain, testis, placenta, and some secretory epithelia. Aloxe3 and Alox12b mRNA was detected in the tongue, forestomach, trachea, brain, testis, and adipose tissue of mice and in the spinal cord of rats.
The Imd pathway is orthologous to human TNF receptor superfamily signalling, and is triggered by Gram-negative bacteria through recognition by peptidoglycan recognition proteins (PGRP) including both soluble receptors and cell surface receptors (PGRP-LE and LC, respectively). Imd signalling culminates in the translocation of the NF-κB transcription factor Relish into the nucleus, leading to the upregulation of Imd-responsive genes including the AMP Diptericin. Consequently, flies deficient for AMPs resemble Imd pathway mutants in terms of susceptibility to bacterial infection. Imd signalling and Relish specifically are also involved in the regulation of immunity at surface epithelia including in the gut and respiratory tracts.
In non-excitable cells, the resting potential across the plasma membrane (Vmem) of individual cells propagate across distances via electrical synapses known as gap junctions (conductors), which allow cells to share their resting potential with neighbors. Aligned and stacked cells (such as in epithelia) generate transepithelial potentials (battery in series) and electric fields (Figures 2 and 3), which likewise propagate across tissues. Tight junctions (resistors) efficiently mitigate the paracellular ion diffusion and leakage, precluding the voltage short circuit. Together, these voltages and electric fields form rich and dynamic and patterns (Figure 5) inside living bodies that demarcate anatomical features, thus acting like blueprints for gene expression and morphogenesis in some instances.
Elafin, the skin-derived elastase inhibitor, has been shown to be a potent and specific inhibitor of both the porcine homolog of ELA1 and human leukocyte elastase in vitro. Elafin is expressed by epidermal keratinocytes under hyperproliferative conditions such as psoriasis and wound healing. It has also been reported to be present in many other adult epithelia that are exposed to environmental stimuli: tongue, plate, lingual tonsils, gingiva, pharynx, epiglottis, vocal fold, esophagus, uterine cervix, vagina, and hair follicles. In all these tissues, the presence of inflammatory cells is physiologic and elafin expression is believed to protect against leukocyte proteases, thereby helping to maintain epithelial integrity.
Plasma membranes also contain carbohydrates, predominantly glycoproteins, but with some glycolipids (cerebrosides and gangliosides). Carbohydrates are important in the role of cell-cell recognition in eukaryotes; they are located on the surface of the cell where they recognize host cells and share information, viruses that bind to cells using these receptors cause an infection For the most part, no glycosylation occurs on membranes within the cell; rather generally glycosylation occurs on the extracellular surface of the plasma membrane. The glycocalyx is an important feature in all cells, especially epithelia with microvilli. Recent data suggest the glycocalyx participates in cell adhesion, lymphocyte homing, and many others.
Facilitated diffusion can occur between the bloodstream and cells as the concentration gradient between the extracellular and intracellular environments is such that no ATP hydrolysis is required. However, in the kidney, glucose is reabsorbed from the filtrate in the tubule lumen, where it is at a relatively low concentration, passes through the simple cuboidal epithelia lining the kidney tubule, and into the bloodstream where glucose is at a comparatively high concentration. Therefore, the concentration gradient of glucose opposes its reabsorption, and energy is required for its transport. The secondary active transport of glucose in the kidney is Na+ linked; therefore an Na+ gradient must be established.
This would make the axes of symmetry consistent with that of other bilaterian phyla and appears to be consistent with the embryological development, in which the body axis folds to bring the shells from the dorsal surface to their mature position. Further support has been identified from the gene expression pattern during development, but on balance, developmental evidence speaks against the BFH. More recent developmental studies have cast doubt on the BFH. Most significantly, the dorsal and ventral valves have significantly different origins; the dorsal (branchial) valve is secreted by dorsal epithelia, whereas the ventral (pedicle) valve corresponds to the cuticle of the pedicle, which becomes mineralized during development.
The fusion proteins formed by these translocations lack the DNA-binding domain, causing the protein to lose function. In gastric cancers (GC), it has been observed that there were lower levels of FOXO4 mRNA in cancers that had already progressed to invading lymph nodes compared to cancers that remained in situ. When compared to normal tissue, all GC epithelia had lower levels of FOXO4 located in the nucleus, consistent with less FOXO4 effector activity and FOXO4's function as a suppressor of carcinogenic properties. It does this by causing cell cycle arrest between the Go and S phases, preventing cell proliferation, as well as by inhibiting metastasis by downregulating vimentin.
Keratin 6B is a type II cytokeratin, one of a number of isoforms of keratin 6. It is found with keratin 16 and/or keratin 17 in the hair follicles, the filiform papillae of the tongue and the epithelial lining of oral mucosa and esophagus. This keratin 6 isoform is thought be less abundant than the closely related keratin 6A protein. Mutations in the gene encoding this protein have been associated with pachyonychia congenita, an inherited disorder of the epithelial tissues in which this keratin is expressed, particularly leading to structural abnormalities of the nails, the epidermis of the palms and soles, and oral epithelia.
Keratohyalin is a protein structure found in cytoplasmic granules of the keratinocytes in the stratum granulosum of the epidermis. Keratohyalin granules (KHG) mainly consist of keratin, profilaggrin, loricrin and trichohyalin proteins which contribute to cornification or keratinization, the process of the formation of epidermal cornified cell envelope. During the keratinocyte differentiation, these granules maturate and expand in size, which leads to the conversion of keratin tonofilaments into a homogenous keratin matrix, an important step in cornification. Keratohyalin granules can be divided in three classes: globular KHG (found in quickly dividing epithelia, such as the oral mucose), stellate KHG (found in the slowly dividing normal epidermis) and KHG of Hassall's corpuscles or type VI epithelioreticular cells of the thymus gland.
The sheep genome has around 27 copies of endogenous retroviruses (enJSRVs) that are closely related to JSRV. Endogenous JSRV has several roles in the evolution of the domestic sheep as they are able to block the JSRV replication cycle and play a critical role in sheep conceptus development and placental morphogenesis. Although OPA resembles human lung cancer, human lung cancer is not known to be caused by betaretroviruses. Even though a possibility of a viral cause has been eliminated in bronchoalveolar cancer, understanding the molecular mechanisms leading to the transformation of lung epithelia by JSRV may be of interest in the context of therapeutic approaches in human lung cancers in general and bronchoalveolar adenocarcinoma (BAC) in particular.
Some embryos have been interpreted as colonies of sulfur-reducing bacteria, a claim that cannot be upheld in all cases. Embryo fossils found in Doushantuo Formation of southern China exhibit occasional asynchronous cell division, common in modern embryos, implying that sophisticated mechanisms for differential cell division timing and embryonic cell lineage differentiation evolved before 551 million years ago. However, embryos composed of hundreds to more than ~1000 cells still show no evidence of blastocoel formation or the organization of blastomeres into epithelia – epithelialization should be underway in modern embryos with >100 cells. Features preserved on Doushantuo embryos are compatible with metazoans (animals), but the absence of epithelialization is consistent only with a stem-metazoan affinity.
The epithelial sodium channel (short: ENaC, also: amiloride-sensitive sodium channel) is a membrane-bound ion channel that is selectively permeable to the ions of sodium (Na+) and that is assembled as a heterotrimer composed of three homologous subunits α or δ, β, and γ, These subunits are encoded by four genes: SCNN1A, SCNN1B, SCNN1G, and SCNN1D. It is involved primarily in the reabsorption of sodium ions at the collecting ducts of the kidney's nephrons. The apical membranes of many tight epithelia contain sodium channels that are characterized primarily by their high affinity for the diuretic blocker amiloride. These channels mediate the first step of active sodium reabsorption essential for the maintenance of body salt and water homeostasis.
Traditionally, inflammasomes have mainly been studied in professional cells of the innate immune system such as macrophages. More recently, however, inflammasome-mediated defense was found to play a crucial role as a first line of defense against bacterial onslaught also at a variety of epithelial sites. Considering the importance of epithelia as common pathogen entry sites as a result of their location at the interface to the environment, it seems intuitive that epithelial tissues do not merely fulfill a function as a physical barrier, but additionally initiate a defensive response upon initial contact with the pathogen. In agreement with this, different inflammasome components were found to be expressed in a variety of epithelial tissues.
Keratinocyte transglutaminase enzymes serve to specifically catalyze the development of the cornified cell envelope, a defining characteristic of epidermal keratinocytes that have undergone the termination of differentiation. The specific cross linkages formed by keratinocyte transglutaminase are between n^ε-(γ-glutamyl)lysine residues which develop into isopeptide protein-protein linkages that adds to the stabilization of the cornified cell envelope. In terminally differentiated stratified squamous epithelia, the cornified cell envelope protein linkages allow for a structurally fortified, yet flexible (15 nm thick) layer to the place of the cell membrane, acting as a highly insoluble barrier. The expression of the enzyme is most highly exhibited along the biological membrane of these fully formed epithelial cells, preventing the cell from undergoing chemical and or physical damages.
While the basic structure of the inner ear in lepidosaurs (lizards and snakes), archosaurs (birds and crocodilians) and mammals is similar, and the organs are considered to be homologous, each group has a unique type of auditory organ. The hearing organ arose within the lagenar duct of stem reptiles, lying between the saccular and lagenar epithelia. In lepidosaurs, the hearing organ, the basilar papilla, is generally small, with at most 2000 hair cells, whereas in archosaurs the basilar papilla can be much longer (>10mm in owls) and contain many more hair cells that show two typical size extremes, the short and the tall hair cells. In mammals, the structure is known as the organ of Corti and shows a unique arrangement of hair cells and supporting cells.
Most sponges work rather like chimneys: they take in water at the bottom and eject it from the osculum ("little mouth") at the top. Since ambient currents are faster at the top, the suction effect that they produce by Bernoulli's principle does some of the work for free. Sponges can control the water flow by various combinations of wholly or partially closing the osculum and ostia (the intake pores) and varying the beat of the flagella, and may shut it down if there is a lot of sand or silt in the water. Although the layers of pinacocytes and choanocytes resemble the epithelia of more complex animals, they are not bound tightly by cell-to-cell connections or a basal lamina (thin fibrous sheet underneath).
This gene encodes a member of a family of candidate taste receptors that are members of the G protein-coupled receptor superfamily and that are specifically expressed by taste receptor cells of the tongue and palate epithelia. These apparently intronless genes encode a 7-transmembrane receptor protein, functioning as a bitter taste receptor. This gene is clustered with another 3 candidate taste receptor genes in chromosome 7 and is genetically linked to loci that influence bitter perception. The geographic distribution of TAS2R4 and TAS2R5 missense allele variants which prevent expression of the receptors is aligned with the distributions of tannin sorghum and the destructive agricultural bird pest in Africa, indicating the role of human taste in developing agroecosystems fitting local environments.
Shigella species invade the host through the M-cells interspersed in the gut epithelia of the small intestine, as they do not interact with the apical surface of epithelial cells, preferring the basolateral side. Shigella uses a type-III secretion system, which acts as a biological syringe to translocate toxic effector proteins to the target human cell. The effector proteins can alter the metabolism of the target cell, for instance leading to the lysis of vacuolar membranes or reorganization of actin polymerization to facilitate intracellular motility of Shigella bacteria inside the host cell. For instance, the IcsA effector (which is an autotransporter instead of type III secretion system effector) protein triggers actin reorganization by N-WASP recruitment of Arp2/3 complexes, helping cell-to-cell spread.
Pathogenically, it is a type II hypersensitivity reaction where circulating complement-fixing IgG antibodies bind to an antigen (a 180-kDa protein, BP-180) in the hemidesmosomes (attach basal cells of epidermis to the basal lamina and hence to dermis) of the dermoepidermal junction, leading to blister formation as loss of hemidesmosomes causes the epidermis to separate from dermis. The immune response is even more highly restricted to the NC16A domain. The primary site of autoimmunity seems not to be the skin, but the placenta, as antibodies bind not only to the basement membrane zone of the epidermis, but also to that of chorionic and amniotic epithelia. Aberrant expression of MHC class II molecules on the chorionic villi suggests an allogenic immune reaction to a placental matrix antigen, thought to be of paternal origin.
The diameter of the tube is not uniform throughout, being greatest at the pharyngeal opening, least at the junction of the bony and cartilaginous portions, and again increased toward the tympanic cavity; the narrowest part of the tube is termed the isthmus. The position and relations of the pharyngeal opening are described with the nasal part of the pharynx. The mucous membrane of the tube is continuous in front with that of the nasal part of the pharynx, and behind with that of the tympanic cavity; it is covered with ciliated pseudostratified columnar epithelia and is thin in the osseous portion, while in the cartilaginous portion it contains many mucous glands and near the pharyngeal orifice a considerable amount of adenoid tissue, which has been named by Gerlach the tube tonsil.
Silicone gel implants can be difficult to emplace via periareolar incision, because of the short, five-centimetre length (~ 5.0 cm) of the required access-incision. Aesthetically, because the scars are at the areola's border (periphery), they usually are less visible than the IMF- incision scars of women with light-pigment areolae; when compared to cutaneous-incision scars, the modified epithelia of the areolae are less prone to (raised) hypertrophic scars. # Transaxillary: an incision made to the axilla (armpit), from which the dissection tunnels medially, to emplace the implants, either bluntly or with an endoscope (illuminated video microcamera), without producing visible scars on the breast proper; yet, it is likelier to produce inferior asymmetry of the implant-device position. Therefore, surgical revision of transaxillary emplaced breast implants usually requires either an IMF incision or a periareolar incision.
The KCNE subunits are potassium channel regulatory subunits that do not pass currents themselves but alter the properties of potassium channel pore-forming alpha subunits. KCNE5 is thus far the least-studied member of the KCNE family, but it is known to regulate a number of different Kv channel subtypes. KCNE5 co-assembles with KCNQ1, a Kv alpha subunit best known for its role in ventricular repolarization and in multiple epithelia. This co-assembly induces a +140 mV shift in voltage dependence of activation (when co-expressed in CHO cells) which would inhibit KCNQ1 activity across the normal physiological voltage range in most tissues. KCNE5 also inhibits activity of channels formed with KCNQ1 and KCNE1. While reportedly not affecting KCNQ2, KCNQ2/3 or KCNQ5 channel activity, KCNE5 inhibits KCNQ4 in CHO cells but not in oocytes.
Trefoil (P-type) domain is a cysteine-rich domain of approximately forty five amino-acid residues has been found in some extracellular eukaryotic proteins. It is known as either the 'P', 'trefoil' or 'TFF' domain, and contains six cysteines linked by three disulphide bonds with connectivity 1-5, 2-4, 3-6. The domain has been found in a variety of extracellular eukaryotic proteins, including protein pS2 (TFF1) a protein secreted by the stomach mucosa; spasmolytic polypeptide (SP) (TFF2), a protein of about 115 residues that inhibits gastrointestinal motility and gastric acid secretion; intestinal trefoil factor (ITF) (TFF3); Xenopus laevis stomach proteins xP1 and xP4; xenopus integumentary mucins A.1 (preprospasmolysin) and C.1, proteins which may be involved in defense against microbial infections by protecting the epithelia from the external environment; xenopus skin protein xp2 (or APEG); Zona pellucida sperm-binding protein B (ZP-B); intestinal sucrase-isomaltase ( / ), a vertebrate membrane bound, multifunctional enzyme complex which hydrolyzes sucrose, maltose and isomaltose; and lysosomal alpha-glucosidase ().
ANGPTL4-deficient mice exhibit delayed wound reepithelialization with impaired keratinocyte migration, angiogenesis and altered inflammatory response. ANGPTL4 induces nitric oxide production through an integrin/JAK/STAT3-mediated upregulation of iNOS expression in wound epithelia, and enhances angiogenesis to accelerate wound healing in diabetic mice. ANGPTL4 induces a β-catenin-mediated upregulation of ID3 in fibroblasts to reduce scar collagen expression. ANGPTL4 is capable of reversing the fibroblast-to-myofibroblast differentiation induced aligned electrospun fibrous substrates. Cyclic stretching of human tendon fibroblasts stimulated the expression and release of ANGPTL4 protein via TGF-β and HIF-1α signalling, and the released ANGPTL4 was pro-angiogenic. ANGPTL4 is also a potent angiogenic factor whose expression is up-regulated in hypoxic retinal Müller cells in vitro and the ischemic retina in vivo. The expression of ANGPTL4 was increased in the aqueous and vitreous of proliferative diabetic retinopathy patients and localized to areas of retinal neovascularization. ANGPTL4 has been established as a potent inhibitor of serum triglyceride (TG) clearance, causing elevation of serum TG levels via inhibition of the enzyme lipoprotein lipase (LPL).

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