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.

Establishment of a tissue culture system for epithelial cells derived from human pancreas: a model for the study of cystic fibrosis

1987 ◽  
Vol 87 (5) ◽  
pp. 695-703
Author(s):  
A. Harris ◽  
L. Coleman
Keyword(s):  
Cystic Fibrosis ◽  
Tissue Culture ◽  
Epithelial Cells ◽  
Culture System ◽  
Cultured Cells ◽  
Cell Types ◽  
Human Pancreas ◽  
Tissue Culture System ◽  
Molecular Biological Analysis

A tissue culture system for epithelial cells derived from human foetal pancreas has been established. The cultured cells show many ultrastructural features of interlobular duct cells. Immunocytochemical and histochemical evidence is presented in support of the view that these cells are ductal in origin. They are likely to be one of the few cell types that express the basic defect of cystic fibrosis in vitro. The cells may be passaged and sufficient material obtained to permit biochemical and molecular biological analysis.

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.

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.

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 Intracellular Colocalization of Influenza Viral RNA and Rab11A Is Dependent upon Microtubule Filaments

2017 ◽  
Vol 91 (19) ◽  
Author(s):  
Eric Nturibi ◽  
Amar R. Bhagwat ◽  
Stefanie Coburn ◽  
Mike M. Myerburg ◽  
Seema S. Lakdawala
Keyword(s):  
Plasma Membrane ◽  
Epithelial Cells ◽  
Cell Types ◽  
Airway Epithelial Cells ◽  
Cytoskeletal Proteins ◽  
Viral Rna ◽  
Airway Epithelial ◽  
Public Health Burden ◽  
Cytoplasmic Transport

ABSTRACT Influenza A virus (IAV) consists of eight viral RNA (vRNA) segments that are replicated in the host cell nucleus and transported to the plasma membrane for packaging into progeny virions. We have previously proposed a model where subcomplexes of vRNA are exported from the nucleus and assembled en route to the plasma membrane. However, the role of host cytoskeletal proteins in the cytoplasmic assembly of IAV vRNA segments remains unknown. Previous studies have suggested that IAV vRNA segments are transported via Rab11A-containing recycling endosomes (RE) and use both microtubules (MT) and actin. Rab11A RE transport primarily along MT; therefore, investigation of the role of MT in vRNA assembly is warranted. We explored the role of MT in vRNA assembly and replication by using multiple IAV strains in various cell types, including primary human airway epithelial cells. We observed that Rab11A localization was altered in the presence of MT-depolymerizing drugs, but growth of IAV in all of the cell types tested was unchanged. Fluorescent in situ hybridization was performed to determine the role of MT in the assembly of multiple vRNA segments. Unexpectedly, we found that vRNA-vRNA association in cytoplasmic foci was independent of MT. Given the disparity of localization between Rab11A and vRNA segments in the absence of intact MT filaments, we analyzed the three-dimensional spatial relationship between Rab11A and vRNA in the cytoplasm of infected cells. We found that Rab11A and vRNA colocalization is dependent upon dynamic MT filaments. Taken together, our data suggest that cytoplasmic transport of influenza vRNA may include a Rab11A RE-independent mechanism. IMPORTANCE IAV infections cause a large public health burden through seasonal epidemics and sporadic pandemics. Pandemic IAVs emerge through reassortment of vRNA in animal or human hosts. Elucidation of the mechanism of intracellular dynamics of IAV assembly is necessary to understand reassortment. Our results describing the role of MT in vRNA transport and assembly expand upon previous studies characterizing vRNA assembly. This study is the first to assess the role of MT in influenza virus replication in human bronchial airway epithelial cells. In addition, we present novel data on the role of MT in facilitating the association between distinct vRNA segments. Interestingly, our results suggest that progressive assembly of vRNA segments may be cell type dependent and that vRNA may be transported through the cytoplasm without Rab11A RE in the absence of intact MT. These results enhance our understanding of vRNA assembly and the role of cytoskeletal proteins in that process.

scholarly journals TGF-β Superfamily Member Nodal Stimulates Human β-Cell Proliferation While Maintaining Cellular Viability

Endocrinology ◽  
2013 ◽  
Vol 154 (11) ◽  
pp. 4099-4112 ◽  
Author(s):  
Brian P. Boerner ◽  
Nicholas M. George ◽  
Natalie M. Targy ◽  
Nora E. Sarvetnick
Keyword(s):  
Cell Proliferation ◽  
Protein Expression ◽  
Cell Types ◽  
Mapk Signaling ◽  
Human Islets ◽  
Human Pancreas ◽  
Cellular Viability ◽  
Β Cell ◽  
Mrna And Protein Expression ◽  
Insulinoma Cells

In an effort to expand human islets and enhance allogeneic islet transplant for the treatment of type 1 diabetes, identifying signaling pathways that stimulate human β-cell proliferation is paramount. TGF-β superfamily members, in particular activin-A, are likely involved in islet development and may contribute to β-cell proliferation. Nodal, another TGF-β member, is present in both embryonic and adult rodent islets. Nodal, along with its coreceptor, Cripto, are pro-proliferative factors in certain cell types. Although Nodal stimulates apoptosis of rat insulinoma cells (INS-1), Nodal and Cripto signaling have not been studied in the context of human islets. The current study investigated the effects of Nodal and Cripto on human β-cell proliferation, differentiation, and viability. In the human pancreas and isolated human islets, we observed Nodal mRNA and protein expression, with protein expression observed in β and α-cells. Cripto expression was absent from human islets. Furthermore, in cultured human islets, exogenous Nodal stimulated modest β-cell proliferation and inhibited α-cell proliferation with no effect on cellular viability, apoptosis, or differentiation. Nodal stimulated the phosphorylation of mothers against decapentaplegic (SMAD)-2, with no effect on AKT or MAPK signaling, suggesting phosphorylated SMAD signaling was involved in β-cell proliferation. Cripto had no effect on human islet cell proliferation, differentiation, or viability. In conclusion, Nodal stimulates human β-cell proliferation while maintaining cellular viability. Nodal signaling warrants further exploration to better understand and enhance human β-cell proliferative capacity.

Chloride currents in primary cultures of rabbit proximal and distal convoluted tubules

1998 ◽  
Vol 275 (5) ◽  
pp. F651-F663 ◽  
Author(s):  
Isabelle Rubera ◽  
Michel Tauc ◽  
Michel Bidet ◽  
Chantal Poujeol ◽  
Béatrice Cuiller ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Cultured Cells ◽  
Primary Cultures ◽  
Physiological Role ◽  
Cell Types ◽  
Patch Clamp Technique ◽  
Chloride Currents ◽  
Hypotonic Stress ◽  
Quantitative Measurements ◽  
Whole Cell Patch Clamp

Cl− conductances were studied in cultured rabbit proximal convoluted tubule (PCT) epithelial cells and compared with those measured in cultured distal bright convoluted tubule (DCTb) epithelial cells. Using the whole cell patch-clamp technique, three types of Cl− conductances were identified in DCTb cultured cells. These consisted of volume-sensitive, Ca2+-activated, and forskolin-activated Cl−currents. In PCT cultured cells, only volume-sensitive and Ca2+-activated Cl− currents were recorded. The characteristics of Ca2+-activated currents in PCT cells closely resembled those in DCTb cells. Volume-sensitive Cl− currents could be elicited both in PCT and in DCTb cells by hypotonic stress. The pharmacological profile of this conductance was established for both cell types. Forskolin activated a linear Cl− current in DCTb cells but not in PCT cells. This conductance was insensitive to DIDS and corresponds to cystic fibrosis transmembrane conductance regulator (CFTR)-like channels. Quantitative measurements of SPQ fluorescence showed that only the apical membrane of DCTb cells possessed a Cl− pathway that was sensitive to forskolin. RT-PCR experiments showed the presence of CFTR mRNA in both cultures, whereas immunostaining experiments revealed the expression of CFTR in DCTb cells only. The physiological role of the different types of channels is discussed.

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.

Effect of Calcium on the Growth and Differentiation of Cultured Rat Esophageal Epithelial Cells

1982 ◽  
Vol 40 ◽  
pp. 132-133
Author(s):  
W.T. Gunning ◽  
M.R. Marino ◽  
M.S. Babcock ◽  
G.D. Stoner
Keyword(s):  
Epithelial Cells ◽  
Cell Types ◽  
Replication Rate ◽  
Enzymatic Dissociation ◽  
Growth Assay ◽  
Epidermal Growth ◽  
Fetal Bovine ◽  
Esophageal Epithelial Cells ◽  
Cellular Replication

The role of calcium in modulating cellular replication and differentiation has been described for various cell types. In the present study, the effects of Ca++ on the growth and differentiation of cultured rat esophageal epithelial cells was investigated.Epithelial cells were isolated from esophagi taken from 8 week-old male CDF rats by the enzymatic dissociation method of Kaighn. The cells were cultured in PFMR-4 medium supplemented with 0.25 mg/ml dialyzed fetal bovine serum, 5 ng/ml epidermal growth factor, 10-6 M hydrocortisone 10-6 M phosphoethanolamine, 10-6 M ethanolamine, 5 pg/ml insulin, 5 ng/ml transferrin, 10 ng/ml cholera toxin and 50 ng/ml garamycin at 36.5°C in a humidified atmosphere of 3% CO2 in air. At weekly intervals, the cells were subcultured with a solution containing 1% polyvinylpyrrolidone, 0.01% EGTA, and 0.05% trypsin. After various passages, the replication rate of the cells in PFMR-4 medium containing from 10-6 M to 10-3 M Ca++ was determined using a clonal growth assay.

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