Epithelial cells retain junctions during mitosis

1993 ◽  
Vol 104 (2) ◽  
pp. 415-425 ◽  
Author(s):  
J. Baker ◽  
D. Garrod
Keyword(s):  
Electron Microscopy ◽  
Epithelial Cells ◽  
Cultured Cells ◽  
Intercellular Junctions ◽  
Cell Types ◽  
Basal Keratinocytes ◽  
Tissue Integrity ◽  
Large Numbers ◽  
Cellular Junctions ◽  
Dividing Cells

It has long been known that cells show reduced cell-substratum adhesion during mitosis in tissue culture, but it is not generally known whether cell-cell adhesion is also reduced. Epithelial cells, both in culture and in tissues, are linked together by several different types of intercellular junctions. Are these junctions disassembled when epithelial cells divide? Cultured epithelial cells were fluorescently stained for desmosomes, tight junctions and zonulae adherentes, and large numbers of dividing cells examined by light microscopy. The results suggested that all three types of intercellular junctions were retained throughout cell division and no evidence for internalization of junctions was obtained. The persistence of intercellular junctions by cultured cells during division was confirmed by electron microscopy. In order to determine whether intercellular junctions were similarly retained by dividing cells in tissues, human colonic mucosal crypt cells and basal keratinocytes were studied by electron microscopy. Both cell types retained intercellular junctions during division. Dividing basal keratinocytes also possessed hemidesmosomal contact with the basement membrane. It is suggested that retention of cellular junctions during division is important for maintenance of tissue integrity and organization.

Cultured epithelial cells derived from human foetal pancreas as a model for the study of cystic fibrosis: further analyses on the origins and nature of the cell types

1988 ◽  
Vol 90 (1) ◽  
pp. 73-77
Author(s):  
A. Harris ◽  
L. Coleman
Keyword(s):  
Cystic Fibrosis ◽  
Tissue Culture ◽  
Epithelial Cells ◽  
Culture System ◽  
Cultured Cells ◽  
Cell Types ◽  
Cultured Epithelial Cells ◽  
Different Cell Types ◽  
Foetal Pancreas

The establishment of a tissue-culture system for epithelial cells derived from human foetal pancreas has recently been reported. Further analyses have now been made on these cells in vitro, together with parallel investigation of the distribution of different cell types within the intact foetal pancreas. Results support the view that the cultured cells are ductal in origin and nature. Pancreatic epithelial cell cultures have also been established from foetuses with cystic fibrosis.

scholarly journals Pantophysin is a ubiquitously expressed synaptophysin homologue and defines constitutive transport vesicles.

1996 ◽  
Vol 134 (3) ◽  
pp. 731-746 ◽  
Author(s):  
N K Haass ◽  
M A Kartenbeck ◽  
R E Leube
Keyword(s):  
Epithelial Cells ◽  
Cultured Cells ◽  
Cell Types ◽  
Human Pancreas ◽  
Cell Fractionation ◽  
Vesicle Membrane ◽  
Cytoplasmic Transport ◽  
Transport Vesicles ◽  
Mrna And Protein Expression ◽  
Exon Structure

Certain properties of the highly specialized synaptic transmitter vesicles are shared by constitutively occurring vesicles. We and others have thus identified a cDNA in various nonneuroendocrine cell types of rat and human that is related to synaptophysin, one of the major synaptic vesicle membrane proteins, which we termed pantophysin. Here we characterize the gene structure, mRNA and protein expression, and intracellular distribution of pantophysin. Its mRNA is detected in murine cell types of nonneuroendocrine as well as of neuroendocrine origin. The intron/exon structure of the murine pantophysin gene is identical to that of synaptophysin except for the last intron that is absent in pantophysin. The encoded polypeptide of calculated mol wt 28,926 shares many sequence features with synaptophysin, most notably the four hydrophobic putative transmembrane domains, although the cytoplasmic end domains are completely different. Using antibodies against the unique carboxy terminus pantophysin can be detected by immunofluorescence microscopy in both exocrine and endocrine cells of human pancreas, and in cultured cells, colocalizing with constitutive secretory and endocytotic vesicle markers in nonneuroendocrine cells and with synaptophysin in cDNA-transfected epithelial cells. By immunoelectron microscopy, the majority of pantophysin reactivity is detected at vesicles with a diameter of < 100 nm that have a smooth surface and an electron-translucent interior. Using cell fractionation in combination with immunoisolation, these vesicles are enriched in a light fraction and shown to contain the cellular vSNARE cellubrevin and the ubiquitous SCAMPs in epithelial cells and synaptophysin in neuroendocrine or cDNA-transfected nonneuroendocrine cells and neuroendocrine tissues. Pantophysin is therefore a broadly distributed marker of small cytoplasmic transport vesicles independent of their content.

scholarly journals Studies on microperoxisomes. VII. Pigment epithelial cells and other cell types in the retina of rodents.

1975 ◽  
Vol 65 (2) ◽  
pp. 324-334 ◽  
Author(s):  
P M Leuenberger ◽  
A B Novikoff
Keyword(s):  
Epithelial Cells ◽  
Vascular Endothelial Cells ◽  
Smooth Endoplasmic Reticulum ◽  
Photoreceptor Cells ◽  
Cell Types ◽  
Vascular Endothelial ◽  
Pigment Epithelial ◽  
Large Numbers ◽  
And Storage ◽  
Pigment Epithelial Cells

The pigment epithelial cell of the retina actively participates in two aspects of lipid metabolism: (a) the fatty acid esterification of vitamin A and its storage and transport to the photoreceptors, and (b) the phagocytosis and degradation of the lipoprotein membrane disks shed from the photoreceptor cells. Study of the pigment epithelial cells of adult albino and pigmented rodents has revealed the abundance of an organelle, microperoxisomes, not previously known to exist in this cell type. The metabolism, transport, and storage of lipids are major functions of other cell types which possess large numbers of microperoxisomes associated with a highly developed smooth endoplasmic reticulum. Microperoxisomes were encountered, but relatively rarely, in Müller cells and vascular endothelial cells. A tubular system in photoreceptor terminals is reactive in the cytochemical procedure used to visualize microperoxisomes.

scholarly journals The Fine Structure of the Wheat Scutellum During Germination

1972 ◽  
Vol 25 (3) ◽  
pp. 469 ◽  
Author(s):  
JG Swift ◽  
TP O'brien
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Epithelial Cells ◽  
Light And Electron Microscopy ◽  
Cell Types ◽  
Wall Material ◽  
Cytological Evidence ◽  
Starch Grains ◽  
Parenchyma Cells ◽  
Cytological Changes

The cytological changes that take place in the scutellar epithelium and parenchyma during the first 5 days of germination are described by light and electron microscopy. Within 6 hr small starch grains appear in the plastids of both cell types and the size and number of starch grains increase gradually as germination proceeds. Later in germination starch disappears again from the plastids in the epithelial cells, but large starch grains still remain in the parenchyma cells. The reserves of the protein bodies are hydrolysed and the residual vacuoles undergo extensive coales-cence. Modifications in the appearance of the wall material of the epithelial cells as these cells elongate are illustrated and possible functional bases for these changes are suggested. The cells of the scutellar epithelium show no cytological evidence for their known functions of diastase secretion and nutrient absorption.

Development of intercellular junctions in the pulmonary epithelium of the foetal lamb

1978 ◽  
Vol 32 (1) ◽  
pp. 307-324
Author(s):  
E.E. Schneeberger ◽  
D.V. Walters ◽  
R.E. Olver
Keyword(s):  
Electron Microscopy ◽  
Epithelial Cells ◽  
Tight Junctions ◽  
Lung Development ◽  
Light And Electron Microscopy ◽  
Intercellular Junctions ◽  
Intercellular Spaces ◽  
Thin Sections ◽  
Epithelial Tight Junctions ◽  
Foetal Lamb

The integrity of epithelial tight junctions in foetal mammalian lungs is essential to maintain the unique ionic composition of lung liquid, and to prevent leakage of serum proteins into peripheral air spaces. In the present study the development of intercellular junctions of the lining epithelium of foetal lamb lungs during gestation was examined by light and electron microscopy. Both thin sections and freeze-fracture replicas were examined by electron microscopy. By 39 days of gestation, epithelial tight junctions consist of a minimum of 3.1 +/− 1.6 (s.D.) and a maximum of 5.8 +/− 2.0 discontinuous rows of particles and short segments of strands on P face ridges and in complementary E face grooves, while from 58 to 76 days they are composed of a network of 4.3 +/− 1.6 to 7.7 +/− 1.9 focally interrupted P face strands. Complementary replicas show that many of the discontinuities on the P face are due to separation of junctional particles on to the E face during fracturing, and not to an absence of junctional particles. From 76 days to term, epithelial tight junctions (exclusive of upper airway epithelium which was not examined) resemble those of adult lungs, and consist of a continuous network of 4.5 +/− 2.0 to 7.5 +/− 2.5 P face strands and complementary particle-free grooves. Permeability measurements, published elsewhere, indicate that the epithelium is functionally ‘tight’ from 69 days onwards. Tight junctions in peripheral air-space epithelium, therefore, are structurally continuous and functionally ‘tight’ early in foetal lung development, and form seals at one end of long, narrow intercellular spaces; these features may be important for coupled ion and water transport. When the bounding epithelial cells become flattened, these narrow intercellular spaces remain intact as a result of complex interdigitations of adjacent cell membranes. Desmosomes were present throughout gestation near the abluminal side of the tight junctions and occasionally near the base of the intercellular space. These junctions may serve to connect cells to each other at a time when tight junctions may be mechanically weak. In addition, gap junctions are associated with tight junctions from the glandular through the canalicular stages of lung development. They disappear by 120 days when the epithelial cells are differentiated.

Ezrin is concentrated in the apical microvilli of a wide variety of epithelial cells whereas moesin is found primarily in endothelial cells

1993 ◽  
Vol 105 (4) ◽  
pp. 1025-1043 ◽  
Author(s):  
M. Berryman ◽  
Z. Franck ◽  
A. Bretscher
Keyword(s):  
Endothelial Cells ◽  
Epithelial Cells ◽  
Cultured Cells ◽  
Cell Types ◽  
Cytoskeletal Proteins ◽  
Specific Cell ◽  
Apical Surface ◽  
Tissue Sections ◽  
Differentiated Cells

Ezrin and moesin are two cytoskeletal proteins originally purified from human placenta that are 74% identical in overall protein sequence. They are believed to be membrane-cytoskeletal linking proteins because they share sequence homology with erythrocyte band 4.1 and colocalize with actin specifically in microvilli and membrane ruffles in cultured cells. To determine if ezrin and moesin share similar distributions in vivo, we studied their localizations with respect to F-actin in tissue sections. Surprisingly, ezrin and moesin exhibited very different cellular distributions. Ezrin was highly concentrated and colocalized with actin on the apical surface of many epithelial cell types. During enterocyte differentiation, the pattern of expression and redistribution of ezrin was consistent with it performing a role in microvillus assembly. Immunoelectron microscopy in differentiated cells revealed that ezrin was restricted mainly to the plasma membrane of microvilli and other actin-rich surface projections. Moesin was found in endothelial cells and was also enriched in the apical microvilli of a restricted set of epithelial cells. All polarized cell types with abundant microvilli contained one or both proteins, suggesting that ezrin and moesin perform related functions. However, the differential expression of ezrin and moesin indicates that they have distinct properties, which are uniquely adapted to specific cell types.

scholarly journals The cell biology of asthma

2014 ◽  
Vol 205 (5) ◽  
pp. 621-631 ◽  
Author(s):  
David J. Erle ◽  
Dean Sheppard
Keyword(s):  
Smooth Muscle ◽  
Epithelial Cells ◽  
Airway Obstruction ◽  
Cell Biology ◽  
Complex Disease ◽  
Cultured Cells ◽  
Clinical Manifestations ◽  
Cell Types ◽  
Airway Epithelial Cells ◽  
Airway Epithelial

The clinical manifestations of asthma are caused by obstruction of the conducting airways of the lung. Two airway cell types are critical for asthma pathogenesis: epithelial cells and smooth muscle cells. Airway epithelial cells, which are the first line of defense against inhaled pathogens and particles, initiate airway inflammation and produce mucus, an important contributor to airway obstruction. The other main cause of airway obstruction is contraction of airway smooth muscle. Complementary experimental approaches involving cultured cells, animal models, and human clinical studies have provided many insights into diverse mechanisms that contribute to airway epithelial and smooth muscle cell pathology in this complex disease.

scholarly journals Superresolution microscopy reveals photoreceptor-specific subciliary location and function of Cep290

2020 ◽  
Author(s):  
Valencia L. Potter ◽  
Abigail R. Moye ◽  
Michael A. Robichaux ◽  
Theodore G. Wensel
Keyword(s):  
Electron Microscopy ◽  
Epithelial Cells ◽  
Fluorescence Microscopy ◽  
Mouse Models ◽  
Primary Cilia ◽  
Cultured Cells ◽  
Precise Location ◽  
Superresolution Microscopy ◽  
Functional Roles ◽  
And Function

AbstractMutations in the cilium-associated protein CEP290 cause retinal degeneration as part of multi-organ syndromic ciliopathies or as retina-specific diseases. The precise location and the functional roles of CEP290 within cilia and, specifically, the connecting cilia (CC) of photoreceptors, remain unclear. We used superresolution fluorescence microscopy and electron microscopy (TEM) to localize CEP290 in the CC and in primary cilia of cultured cells with sub-diffraction resolution, and to determine effects of CEP290 deficiency. Radially, CEP290 co-localizes with the microtubule doublets and extends beyond them. Longitudinally, it is distributed throughout the length of the CC but is strictly confined to the very base of primary cilia in hRPE-1 cells. We found Y-shaped links, the ciliary sub-structures between microtubules and membrane, at the base of the transition zone in primary cilia of epithelial cells and throughout the length of the CC. Severe CEP290 deficiencies in mouse models did not prevent assembly of cilia or cause obvious mislocalization of ciliary components in early stages of degeneration. They did not lead to loss of the Y-shaped links but caused changes in their structures. These results point to photoreceptor-specific functions of CEP290 essential for CC maturation and stability following the earliest stages of ciliogenesis.

Androgen metabolism and actions in rat ventral prostate epithelial and stromal cell cultures

1986 ◽  
Vol 64 (6) ◽  
pp. 583-593 ◽  
Author(s):  
J. Orlowski ◽  
A. F. Clark
Keyword(s):  
Epithelial Cells ◽  
Cell Cultures ◽  
Stromal Cells ◽  
Stromal Cell ◽  
Cultured Cells ◽  
Cell Types ◽  
Ventral Prostate ◽  
Oxidoreductase Activity ◽  
Androgen Metabolism ◽  
Rat Ventral Prostate

The rat ventral prostate requires androgens for normal development, growth, and function. To investigate the relationship between androgen metabolism and its effects in the prostate and to examine differences between the epithelial and stromal cells, we have established a system of primary cell cultures of immature rat ventral prostate cells. Cultures of both cell types after reaching confluency (6–7 days) actively metabolized 3H-labelled testosterone (T), 5α-dihydrotestosterone (5α-DHT), 5α-androstane-3α,17β-diol, and 5α-androstane-3β,17β-diol. The epithelial cells actively reduced T to 5α-DHT and formed significant amounts of 5α-androstane-3,17-dione from T, 5α-DHT, and 5α-androstane-3α,17β-diol. All substrates were converted to significant amounts of C19O3metabolites. The stromal cells also metabolized all substrates, but very little 5α-androstane-3,17-dione was formed. The metabolism studies indicate that both cell types have Δ4-5α-reductase, 3α- and 3β-hydroxysteroid oxidoreductase and hydroxylase activities. The epithelial cells have significant 17β-hydroxysteroid oxidoreductase activity. The epithelial cells cultures grown in the presence of T have higher acid phosphatase (AP) contents (demonstrated histochemically and by biochemical assay). Tartrate inhibition studies indicate that the epithelial cells grown in the presence of T are making secretory AP. Stromal cell AP is not influenced by T. The results indicate that the cultured cells maintain differentiated prostatic functions: ability to metabolize androgens and, in the case of the epithelial cells, synthesize secretory AP.

scholarly journals Junctional abnormalities in human airway epithelial cells expressing F508del CFTR

2015 ◽  
Vol 309 (5) ◽  
pp. L475-L487 ◽  
Author(s):  
Samuel A. Molina ◽  
Brandon Stauffer ◽  
Hannah K. Moriarty ◽  
Agnes H. Kim ◽  
Nael A. McCarty ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Gap Junction ◽  
Lectin Binding ◽  
Intercellular Junctions ◽  
Cell Types ◽  
Airway Epithelial Cells ◽  
Transepithelial Resistance ◽  
Dye Transfer ◽  
Human Airway ◽  
Airway Cells

Cystic fibrosis (CF) has a profound impact on airway physiology. Accumulating evidence suggests that intercellular junctions are impaired in CF. We examined changes to CF transmembrane conductance regulator (CFTR) function, tight junctions, and gap junctions in NuLi-1 (CFTRwt/wt) and CuFi-5 (CFTRΔF508/ΔF508) cells. Cells were studied at air-liquid interface (ALI) and compared with primary human bronchial epithelial cells. On the basis of fluorescent lectin binding, the phenotype of the NuLi-1 and CuFi-5 cells at week 8 resembled that of serous, glycoprotein-rich airway cells. After week 7, CuFi-5 cells possessed 130% of the epithelial Na+ channel activity and 17% of the CFTR activity of NuLi-1 cells. In both cell types, expression levels of CFTR were comparable to those in primary airway epithelia. Transepithelial resistance of NuLi-1 and CuFi-5 cells stabilized during maturation in ALI culture, with significantly lower transepithelial resistance for CuFi-5 than NuLi-1 cells. We also found that F508del CFTR negatively affects gap junction function in the airway. NuLi-1 and CuFi-5 cells express the connexins Cx43 and Cx26. While both connexins were properly trafficked by NuLi-1 cells, Cx43 was mistrafficked by CuFi-5 cells. Cx43 trafficking was rescued in CuFi-5 cells treated with 4-phenylbutyric acid (4-PBA), as assessed by intracellular dye transfer. 4-PBA-treated CuFi-5 cells also exhibited an increase in forskolin-induced CFTR-mediated currents. The Cx43 trafficking defect was confirmed using IB3-1 cells and found to be corrected by 4-PBA treatment. These data support the use of NuLi-1 and CuFi-5 cells to examine the effects of F508del CFTR expression on tight junction and gap junction function in the context of serous human airway cells.

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