scholarly journals A Novel Monoclonal Antibody Against the Second Extracellular Loop of Occludin Disrupts Epithelial Cell Polarity

2007 ◽  
Vol 55 (7) ◽  
pp. 735-744 ◽  
Author(s):  
Yuichi Tokunaga ◽  
Takashi Kojima ◽  
Makoto Osanai ◽  
Masaki Murata ◽  
Hideki Chiba ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Cell Polarity ◽  
Basolateral Membrane ◽  
Epithelial Cell Line ◽  
Intestinal Epithelial ◽  
Extracellular Loop ◽  
T84 Cells ◽  
Epithelial Cell Polarity ◽  
Apical Membranes ◽  
Fence Function

The tight junction (TJ) regulates epithelial cell polarity and paracellular permeability. In the present study, to investigate whether the second extracellular loop of occludin affects the localization of carcinoembryonic antigen (CEA) and CD26 expressed on apical membranes, and the fence function of the TJ, the human intestinal epithelial cell line T84 was treated with the monoclonal anti-occludin antibody (MAb) 1H8, corresponding to the second extracellular loop of occludin. In T84 cells treated with MAb 1H8, occludin disappeared, and CEA and CD26 were observed to diffuse from the apical membrane to the basolateral membrane. Furthermore, a decrease in the fence function of TJ was observed without changes in the TJ strands and barrier function. When T84 cells precultured in low calcium (Ca) medium were recultured in normal Ca medium in the presence of MAb 1H8, recruitment of occludin to the apical-most membranes and recovery in distribution of CEA and CD26 were markedly retarded compared with the control. These results suggested that MAb 1H8 against the second extracellular loop of occludin selectively affected formation of the apical/basolateral intramembrane diffusion barrier and that the second extracellular loop of occludin plays a crucial role in the maintenance of epithelial cell polarity by the TJ.

scholarly journals Translocation of verotoxin-1 across T84 monolayers: mechanism of bacterial toxin penetration of epithelium

1997 ◽  
Vol 273 (6) ◽  
pp. G1349-G1358 ◽  
Author(s):  
Dana J. Philpott ◽  
Cameron A. Ackerley ◽  
Amanda J. Kiliaan ◽  
Mohamed A. Karmali ◽  
Mary H. Perdue ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Barrier Function ◽  
Pathogenic Bacteria ◽  
Intestinal Epithelial Cell ◽  
Cell Function ◽  
Bacterial Toxin ◽  
General Mechanism ◽  
Epithelial Cell Line ◽  
Intestinal Epithelial ◽  
T84 Cells

Verotoxin-producing Escherichia coli (VTEC) are pathogenic bacteria associated with diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome. Verotoxins (VTs) elaborated by these organisms produce cytopathic effects on a restricted number of cell types, including endothelial cells lining the microvasculature of the bowel and the kidney. Because human intestinal epithelial cells lack the globotriaosylceramide receptor for VT binding, it is unclear how the toxin moves across the intestinal mucosa to the systemic circulation. The aims of this study were to determine the effects of VT-1 on intestinal epithelial cell function and to characterize VT-1 translocation across monolayers of T84 cells, an intestinal epithelial cell line. VT-1 at concentrations up to 1 μg/ml had no effect on the barrier function of T84 monolayers as assessed by measuring transmonolayer electrical resistance (102 ± 8% of control monolayers). In contrast, both VT-positive and VT-negative VTEC bacterial strains lowered T84 transmonolayer resistance (45 ± 7 and 38 ± 6% of controls, respectively). Comparable amounts of toxin moved across monolayers of T84 cells, exhibiting high-resistance values, as monolayers with VTEC-induced decreases in barrier function, suggesting a transcellular mode of transport. Translocation of VT-1 across T84 monolayers paralleled the movement of a comparably sized protein, horseradish peroxidase. Immunoelectron microscopy confirmed transcellular transport of VT-1, since the toxin was observed within endosomes and associated with specific intracellular targets, including the Golgi network and endoplasmic reticulum. These data present a mode of VT-1 uptake by toxin-insensitive cells and suggest a general mechanism by which bacterial toxins lacking specific intestinal receptors can penetrate the intestinal epithelial barrier.

scholarly journals The PTEN Phosphatase Controls Intestinal Epithelial Cell Polarity and Barrier Function: Role in Colorectal Cancer Progression

PLoS ONE ◽  
2010 ◽  
Vol 5 (12) ◽  
pp. e15742 ◽  
Author(s):  
Marie-Josée Langlois ◽  
Sébastien Bergeron ◽  
Gérald Bernatchez ◽  
François Boudreau ◽  
Caroline Saucier ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Epithelial Cell ◽  
Cell Polarity ◽  
Cancer Progression ◽  
Barrier Function ◽  
Intestinal Epithelial Cell ◽  
Intestinal Epithelial ◽  
Epithelial Cell Polarity ◽  
Colorectal Cancer Progression

scholarly journals Intestinal epithelial cell polarity defects in disease: lessons from microvillus inclusion disease

2018 ◽  
Vol 11 (2) ◽  
pp. dmm031088 ◽  
Author(s):  
Kerstin Schneeberger ◽  
Sabrina Roth ◽  
Edward E. S. Nieuwenhuis ◽  
Sabine Middendorp
Keyword(s):  
Epithelial Cell ◽  
Cell Polarity ◽  
Intestinal Epithelial Cell ◽  
Intestinal Epithelial ◽  
Epithelial Cell Polarity

scholarly journals Disruptionof Cell Polarity by Enteropathogenic Escherichia coli EnablesBasolateral Membrane Proteins To Migrate Apically and ToPotentiate PhysiologicalConsequences

2003 ◽  
Vol 71 (12) ◽  
pp. 7069-7078 ◽  
Author(s):  
Michelle M. Muza-Moons ◽  
Athanasia Koutsouris ◽  
Gail Hecht
Keyword(s):  
Escherichia Coli ◽  
Membrane Proteins ◽  
Cell Polarity ◽  
Host Cells ◽  
Intestinal Epithelial ◽  
T84 Cells ◽  
Intimate Contact ◽  
Calcium Chelation ◽  
The Impact ◽  
Fence Function

ABSTRACT Enteropathogenic Escherichia coli (EPEC) disrupts the structure and barrier function of host intestinal epithelial tight junctions (TJs). The impact of EPEC on TJ “fence function,” i.e., maintenance of cell polarity, has not been investigated. In polarized cells, proteins such as β1-integrin and Na+/K+ ATPase are restricted to basolateral (BL) membranes. The outer membrane EPEC protein intimin possesses binding sites for the EPEC translocated intimin receptor (Tir) and β1-integrin. Restriction ofβ 1-integrin to BL domains, however, precludes opportunity for interaction. We hypothesize that EPEC perturbs TJ fence function and frees BL proteins such as β1-integrin to migrate to apical (AP) membranes of host cells, thus allowing interactions with bacterial adhesins such as intimin. The aim of this study was to determine whether EPEC alters the polar distribution of BL proteins, in particular β1-integrin, and if such redistribution contributes to pathogenesis. Human intestinal epithelial T84 cells and EPEC strain E2348/69 were used. Selective biotinylation of AP or BL membrane proteins and confocal microscopy showed the presence of β1-integrin and Na+/K+ ATPase on the AP membrane following infection. β1-Integrin antibody afforded no protection against the initial EPEC-induced decrease in transepithelial electrical resistance (TER) but halted the progressive decrease at later time points. While the effects of EPEC on TJ barrier and fence function were Tir dependent, disruption of cell polarity by calcium chelation allowed a tir mutant to be nearly as effective as wild-type EPEC. In contrast, deletion of espD, which renders the type III secretory system ineffective, had no effect on TER even after calcium chelation, suggesting that the putativeβ 1-integrin-intimin interaction serves to provide intimate contact, like that of Tir and intimin, making translocation of effector molecules more efficient. We conclude that the initial alterations of TJ barrier and fence function by EPEC are Tir dependent but that later disruption of cell polarity and accessibility of EPEC to BL membrane proteins, such asβ 1-integrin, potentiates the physiological perturbations.

scholarly journals A picket fence function for adherens junctions in epithelial cell polarity

2021 ◽  
pp. 203719
Author(s):  
Teresa Bonello ◽  
Mario Aguilar-Aragon ◽  
Alexander Tournier ◽  
Barry J. Thompson
Keyword(s):  
Epithelial Cell ◽  
Cell Polarity ◽  
Adherens Junctions ◽  
Epithelial Cell Polarity ◽  
Picket Fence ◽  
Fence Function

scholarly journals Biogenetic pathways of plasma membrane proteins in Caco-2, a human intestinal epithelial cell line.

1990 ◽  
Vol 111 (4) ◽  
pp. 1351-1361 ◽  
Author(s):  
A Le Bivic ◽  
A Quaroni ◽  
B Nichols ◽  
E Rodriguez-Boulan
Keyword(s):  
Epithelial Cell ◽  
Cell Line ◽  
Transferrin Receptor ◽  
Apical Membrane ◽  
Mdck Cells ◽  
Basolateral Membrane ◽  
Epithelial Cell Line ◽  
Apical Surface ◽  
Intestinal Epithelial ◽  
Human Intestinal Epithelial Cell

We studied the sorting and surface delivery of three apical and three basolateral proteins in the polarized epithelial cell line Caco-2, using pulse-chase radiolabeling and surface domain-selective biotinylation (Le Bivic, A., F. X. Real, and E. Rodriguez-Boulan. 1989. Proc. Natl. Acad. Sci. USA. 86:9313-9317). While the basolateral proteins (antigen 525, HLA-I, and transferrin receptor) were targeted directly and efficiently to the basolateral membrane, the apical markers (sucrase-isomaltase [SI], aminopeptidase N [APN], and alkaline phosphatase [ALP]) reached the apical membrane by different routes. The large majority (80%) of newly synthesized ALP was directly targeted to the apical surface and the missorted basolateral pool was very inefficiently transcytosed. SI was more efficiently targeted to the apical membrane (greater than 90%) but, in contrast to ALP, the missorted basolateral pool was rapidly transcytosed. Surprisingly, a distinct peak of APN was detected on the basolateral domain before its accumulation in the apical membrane; this transient basolateral pool (at least 60-70% of the enzyme reaching the apical surface, as measured by continuous basal addition of antibodies) was efficiently transcytosed. In contrast with their transient basolateral expression, apical proteins were more stably localized on the apical surface, apparently because of their low endocytic capability in this membrane. Thus, compared with two other well-characterized epithelial models, MDCK cells and the hepatocyte, Caco-2 cells have an intermediate sorting phenotype, with apical proteins using both direct and indirect pathways, and basolateral proteins using only direct pathways, during biogenesis.

scholarly journals New Perspectives on Mechanisms Involved in Generating Epithelial Cell Polarity

1999 ◽  
Vol 79 (1) ◽  
pp. 73-98 ◽  
Author(s):  
CHARLES YEAMAN ◽  
KENT K. GRINDSTAFF ◽  
W. JAMES NELSON
Keyword(s):  
Epithelial Cell ◽  
Cell Surface ◽  
Cell Polarity ◽  
Basolateral Membrane ◽  
Direct Consequence ◽  
Cytoskeletal Proteins ◽  
Critical Event ◽  
Surface Polarity ◽  
Epithelial Cell Polarity ◽  
Signal Transduction Proteins

Yeaman, Charles, Kent K. Grindstaff, and W. James Nelson. New Perspectives on Mechanisms Involved in Generating Epithelial Cell Polarity. Physiol. Rev. 79: 73–98, 1999. — Polarized epithelial cells form barriers that separate biological compartments and regulate homeostasis by controlling ion and solute transport between those compartments. Receptors, ion transporters and channels, signal transduction proteins, and cytoskeletal proteins are organized into functionally and structurally distinct domains of the cell surface, termed apical and basolateral, that face these different compartments. This review is about mechanisms involved in the establishment and maintenance of cell polarity. Previous reports and reviews have adopted a Golgi-centric view of how epithelial cell polarity is established, in which the sorting of apical and basolateral membrane proteins in the Golgi complex is a specialized process in polarized cells, and the generation of cell surface polarity is a direct consequence of this process. Here, we argue that events at the cell surface are fundamental to the generation of cell polarity. We propose that the establishment of structural asymmetry in the plasma membrane is the first, critical event, and subsequently, this asymmetry is reinforced and maintained by delivery of proteins that were constitutively sorted in the Golgi. We propose a hierarchy of stages for establishing cell polarity.

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