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Biochimica Et Biophysica Acta.... Feb 2020Tricellular junctions are specialized cell-cell junctions formed at sites where three epithelial or endothelial cells make contact at their apical side. By holding three... (Review)
Review
Tricellular junctions are specialized cell-cell junctions formed at sites where three epithelial or endothelial cells make contact at their apical side. By holding three cells together, tricellular junctions contribute to the maintenance of epithelial barrier function and mechanical integrity. In addition, recent studies have uncovered new functions of tricellular junctions at both cellular and physiological levels. In this review, we describe the architecture and molecular components of tricellular junctions and discuss how tricellular junctions participate in various biological processes.
Topics: Adherens Junctions; Animals; Desmosomes; Epithelial Cells; Humans; Tight Junction Proteins; Tight Junctions
PubMed: 31812626
DOI: 10.1016/j.bbamem.2019.183143 -
The FEBS Journal Dec 2021Cell polarity is a fundamental property of most animal cells and is critical during development and for most cell and tissue functions. Epithelial cells are organized... (Review)
Review
Cell polarity is a fundamental property of most animal cells and is critical during development and for most cell and tissue functions. Epithelial cells are organized into apical and basolateral compartments, and this intrinsic cellular asymmetry is essential for all functions that are carried out by epithelial tissue. The establishment of a polarized epithelial phenotype is orchestrated by major rearrangements of the cell cytoskeleton, polarized membrane trafficking, the formation and maturation of epithelial cell junctions, cell signaling pathways, and the generation of cortical phospholipid asymmetry. These processes need to be coordinated precisely in time and space and integrated with physical and chemical signals from the environment, failure of which leads to severe developmental disorders and various human diseases. At the heart of this regulatory network are the evolutionarily conserved polarity modules Par, Crumbs, and Scribble, whose components engage in complex cooperative and antagonistic interactions to compartmentalize and functionalize the epithelial cell cortex and to control the spatiotemporal activity of downstream polarity effectors. In this review, we will discuss recent insights into the organization and regulation of the mammalian Par and Crumbs modules and outline a hypothetical framework of how these proteins orchestrate epithelial polarity development, HIPPO signaling, and actomyosin activity at the apical-lateral border.
Topics: Animals; Cell Polarity; Epithelial Cells; Humans
PubMed: 33448150
DOI: 10.1111/febs.15710 -
BMC Cell Biology Oct 2011The MDCK cell line provides a tractable model for studying protein trafficking, polarity and junctions (tight, adherens, desmosome and gap) in epithelial cells. However,... (Review)
Review
The MDCK cell line provides a tractable model for studying protein trafficking, polarity and junctions (tight, adherens, desmosome and gap) in epithelial cells. However, there are many different strains of MDCK cells available, including the parental line, MDCK I, MDCK II, MDCK.1, MDCK.2, superdome and supertube, making it difficult for new researchers to decide which strain to use. Furthermore, there is often inadequate reporting of strain types and where cells were obtained from in the literature. This review aims to provide new researchers with a guide to the different MDCK strains and a directory of where they can be obtained. We also hope to encourage experienced researchers to report the stain and origin of their MDCK cells.
Topics: Animals; Cell Adhesion; Cell Culture Techniques; Cell Line; Cell Movement; Cell Polarity; Disease Models, Animal; Dogs; Epithelial Cells; Humans; Kidney; Practice Guidelines as Topic; Species Specificity; Virus Diseases
PubMed: 21982418
DOI: 10.1186/1471-2121-12-43 -
Biochimica Et Biophysica Acta.... Jun 2018Entosis is a form of epithelial cell engulfment and cannibalism prevalent in human cancer. Until recently, the only known trigger for entosis was loss of attachment to... (Review)
Review
Entosis is a form of epithelial cell engulfment and cannibalism prevalent in human cancer. Until recently, the only known trigger for entosis was loss of attachment to the extracellular matrix, as often occurs in the tumour microenvironment. However, two new studies now reveal that entosis can also occur among adherent epithelial cells, induced by mitosis or glucose starvation. Together, these findings point to the intriguing notion that certain hallmark properties of cancer cells, including anchorage independence, aberrant proliferation and metabolic stress, can converge on the induction of cell cannibalism, a phenomenon so frequently observed in tumours. In this review, we explore the molecular, cellular and biophysical mechanisms underlying entosis and discuss the impact of cell cannibalism on tumour biology.
Topics: Entosis; Epithelial Cells; Humans; Mitosis; Neoplasms
PubMed: 29548938
DOI: 10.1016/j.bbamcr.2018.03.004 -
Scientific Reports Mar 2021The tumoral origin and extensive passaging of HeLa cells, a most commonly used cervical epithelial cell line, raise concerns on their suitability to study the cell...
The tumoral origin and extensive passaging of HeLa cells, a most commonly used cervical epithelial cell line, raise concerns on their suitability to study the cell responses to infection. The present study was designed to isolate primary epithelial cells from human ectocervix explants and characterize their susceptibility to C. trachomatis infection. We achieved a high purity of isolation, assessed by the expression of E-cadherin and cytokeratin 14. The infectious progeny in these primary epithelial cells was lower than in HeLa cells. We showed that the difference in culture medium, and the addition of serum in HeLa cultures, accounted for a large part of these differences. However, all things considered the primary ectocervical epithelial cells remained less permissive than HeLa cells to C. trachomatis serovar L2 or D development. Finally, the basal level of transcription of genes coding for pro-inflammatory cytokines was globally higher in primary epithelial cells than in HeLa cells. Transcription of several pro-inflammatory genes was further induced by infection with C. trachomatis serovar L2 or serovar D. In conclusion, primary epithelial cells have a strong capacity to mount an inflammatory response to Chlamydia infection. Our simplified purification protocol from human explants should facilitate future studies to understand the contribution of this response to limiting the spread of the pathogen to the upper female genital tract.
Topics: Cell Proliferation; Cell Separation; Cell Shape; Cervix Uteri; Chlamydia Infections; Chlamydia trachomatis; Epithelial Cells; Female; Fibroblasts; HeLa Cells; Humans; Immunity; Inflammation
PubMed: 33712643
DOI: 10.1038/s41598-021-85123-7 -
Tissue Barriers 2018Epithelial cells have characteristic membrane domains. Identification of membrane proteins playing an important role in these membrane domains has progressed and... (Review)
Review
Epithelial cells have characteristic membrane domains. Identification of membrane proteins playing an important role in these membrane domains has progressed and numerous studies have been performed on the functional analysis of these membrane proteins. On the other hand, the precise roles of membrane lipids in the organization of these membrane domains are largely unknown. Historically, the concept of lipid raft arose from the analysis of lipid composition of the apical membrane, and it can be said that epithelial cells are an optimal experimental model for elucidating the functions of lipids. In this review, I discuss the role of lipids in the formation of epithelial polarity and in the formation of cell membrane structures of epithelial cells such as microvilli in the apical domain, cell-cell adhesion apparatus in the lateral domain and cell-matrix adhesion in the basal domain.
Topics: Animals; Epithelial Cells; Humans; Membrane Lipids
PubMed: 30156967
DOI: 10.1080/21688370.2018.1502531 -
Cell Proliferation Oct 2003An entire mammary epithelial outgrowth, capable of full secretory differentiation, may be comprised of the progeny of a single cellular antecedent. This conclusion is... (Review)
Review
An entire mammary epithelial outgrowth, capable of full secretory differentiation, may be comprised of the progeny of a single cellular antecedent. This conclusion is based upon the maintenance of retroviral insertion sites within the somatic DNA of successive transplant generations derived from a single mammary fragment. In addition, dissociation of these clonal dominant glands and implantation of dispersed cells at limiting dilution demonstrated that both duct-limited and lobule-limited outgrowths were developed, as well as complete, fully differentiated glands. Thus, transplantation has revealed three distinct mammary epithelial progenitors in the mouse. Similar studies have extended this observation to rat mammary tissue. Recently, using cre-lox conditional activation of reporter genes, a new epithelial progenitor, specific for mammary secretory epithelium in postlactation females has been uncovered. In situ, these cells were shown to regenerate secretory lobules upon successive pregnancies. In transplant studies, they demonstrated the capacity for self-renewal and contributed to the new generation of all of the known epithelial cell types among mammary epithelium. In limiting dilution, the parity-induced progenitors were capable of engendering lobule-limited and duct-limited outgrowths in their entirety, but not completely developed glands. Serial transplant studies indicate that these progenitors have a significant but limited capacity for self-renewal.
Topics: Animals; Epithelial Cells; Mammary Glands, Animal; Stem Cell Transplantation; Stem Cells
PubMed: 14521512
DOI: 10.1046/j.1365-2184.36.s.1.2.x -
Veterinary Microbiology May 2012IPEC-J2 cells are porcine intestinal columnar epithelial cells that were isolated from neonatal piglet mid-jejunum. This cell line forms polarized monolayers with high... (Review)
Review
IPEC-J2 cells are porcine intestinal columnar epithelial cells that were isolated from neonatal piglet mid-jejunum. This cell line forms polarized monolayers with high transepithelial electrical resistance when cultured on 0.4 μm pore-size filters. The cell line is unique in that it is derived from small intestinal tissue (compared to the common human colon-derived lines HT-29, T84, and Caco-2) and is not transformed (compared to the porcine small intestinal line, IPI-2I). Porcine intestinal epithelial cells more closely mimic human physiology than analogous rodent cell lines (e.g. IEC-6 or IEC-18), which is important in studies of zoonotic infections; in addition, they provide specificity to study porcine-derived infections. IPEC-J2 cells are increasingly being used in microbiological studies to examine the interactions of various animal and human pathogens, including Salmonella enterica and pathogenic Escherichia coli, with intestinal epithelial cells. The IPEC-J2 cell line has also been employed in some probiotic studies, in which the cells have been used as an initial screening tool for adhesiveness and anti-inflammatory properties of the potential probiotic microorganisms. The validity of these studies is not clear as follow-up studies to assess the efficacy of the probiotics in vivo have not been published to date. The aims of this review are to provide a comprehensive overview of the microbiological studies that have been conducted with IPEC-J2 cells and a reference guide of key cellular and immune markers that have been identified in this cell line that may prove to be useful in future studies.
Topics: Animals; Cell Line; Epithelial Cells; Escherichia coli; Jejunum; Probiotics; Salmonella enterica; Sus scrofa
PubMed: 22074860
DOI: 10.1016/j.vetmic.2011.10.017 -
Journal of Biomedicine & Biotechnology 2011Countless in vitro cell culture models based on the use of epithelial cell types of single lineages have been characterized and have provided insight into the mechanisms... (Review)
Review
Countless in vitro cell culture models based on the use of epithelial cell types of single lineages have been characterized and have provided insight into the mechanisms of infection for various microbial pathogens. Diverse culture models based on disease-relevant mucosal epithelial cell types derived from gastrointestinal, genitourinary, and pulmonary organ systems have delineated many key host-pathogen interactions that underlie viral, parasitic, and bacterial disease pathogenesis. An alternative to single lineage epithelial cell monoculture, which offers more flexibility and can overcome some of the limitations of epithelial cell culture models based on only single cell types, is coculture of epithelial cells with other host cell types. Various coculture models have been described, which incorporate epithelial cell types in culture combination with a wide range of other cell types including neutrophils, eosinophils, monocytes, and lymphocytes. This paper will summarize current models of epithelial cell coculture and will discuss the benefits and limitations of epithelial cell coculture for studying host-pathogen dynamics in infectious diseases.
Topics: Cell Culture Techniques; Coculture Techniques; Communicable Diseases; Epithelial Cells; Host-Pathogen Interactions; Humans; Models, Biological
PubMed: 22007147
DOI: 10.1155/2011/852419 -
Scientific Reports Mar 2020Enamel is secreted by ameloblasts derived from tooth epithelial stem cells (SCs). Humans cannot repair or regenerate enamel, due to early loss of tooth epithelial SCs....
Enamel is secreted by ameloblasts derived from tooth epithelial stem cells (SCs). Humans cannot repair or regenerate enamel, due to early loss of tooth epithelial SCs. Contrarily in the mouse incisors, epithelial SCs are maintained throughout life and endlessly generate ameloblasts, and thus enamel. Here we isolated Sox2-GFP+ tooth epithelial SCs which generated highly cellular spheres following a novel in vitro strategy. This system enabled analysis of SC regulation by various signaling molecules, and supported the stimulatory and inhibitory roles of Shh and Bmp, respectively; providing better insight into the heterogeneity of the SCs. Further, we generated a novel mouse reporter, Enamelin-tdTomato for identification of ameloblasts in live tissues and cells, and used it to demonstrate presence of ameloblasts in the new 3D co-culture system of dental SCs. Collectively, our results provide means of generating 3D tooth epithelium from adult SCs which can be utilized toward future generation of enamel.
Topics: Ameloblasts; Animals; Cell Differentiation; Cells, Cultured; Coculture Techniques; Epithelial Cells; Mice; Mice, Inbred C57BL; Signal Transduction; Stem Cells; Tooth
PubMed: 32188889
DOI: 10.1038/s41598-020-60708-w