Enteropathogenic Escherichia coli adherence to intestinal epithelial monolayers diminishes barrier function

1995 ◽  
Vol 268 (2) ◽  
pp. G374-G379 ◽  
Author(s):  
J. Spitz ◽  
R. Yuhan ◽  
A. Koutsouris ◽  
C. Blatt ◽  
J. Alverdy ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Host Cell ◽  
Barrier Function ◽  
Cell Function ◽  
Cytoskeletal Proteins ◽  
Calcium Stores ◽  
Intestinal Epithelial ◽  
Enteropathogenic Escherichia Coli ◽  
Wild Type ◽  
Cell Monolayers

The mechanism by which enteropathogenic Escherichia coli (EPEC) causes diarrhea remains elusive. Several alterations within the host cell have been demonstrated to occur following EPEC attachment including increases in intracellular Ca2+ concentration and rearrangement and phosphorylation of several cytoskeletal proteins. The consequences of these intracellular perturbations on host cell function, however, have not been determined. The aim of this study was to examine the effect of EPEC adherence on intestinal epithelial barrier function. T84 cell monolayers were infected with either wild-type EPEC or a nonadherent isogenic derivative. Transepithelial electrical resistance, a measure of barrier function, decreased 33.5 +/- 6.4% after a 6-h incubation with the wild-type strain. Electron microscopy revealed ultrastructurally normal cells, and lactate dehydrogenase release assays failed to demonstrate cytotoxicity. Dual 22Na+ and [3H]mannitol flux studies localized the permeability defect to tight junctions. In addition, cumulative flux of the paracellular marker mannitol was four- to fivefold greater across monolayers infected with wild-type EPEC. Sequestration of intracellular calcium stores by dantrolene completely abrogated the resistance drop associated with EPEC attachment. These data demonstrate that adherence of EPEC to intestinal epithelial cell monolayers disrupts tight junction barrier function via a calcium-requiring event.

scholarly journals Arctigenin fromFructus Arctii(Seed of Burdock) Reinforces Intestinal Barrier Function in Caco-2 Cell Monolayers

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Hee Soon Shin ◽  
Sun Young Jung ◽  
Su Yeon Back ◽  
Jeong-Ryong Do ◽  
Dong-Hwa Shon
Keyword(s):  
Barrier Function ◽  
Active Component ◽  
Inflammatory Diseases ◽  
Intestinal Barrier ◽  
Transepithelial Electrical Resistance ◽  
Intestinal Barrier Function ◽  
Intestinal Epithelial ◽  
Traditional Herbal Medicine ◽  
Cell Monolayers ◽  
Basolateral Side

Fructus Arctiiis used as a traditional herbal medicine to treat inflammatory diseases in oriental countries. This study aimed to investigate effect ofF. Arctiiextract on intestinal barrier function in human intestinal epithelial Caco-2 cells and to reveal the active component ofF. Arctii. We measured transepithelial electrical resistance (TEER) value (as an index of barrier function) and ovalbumin (OVA) permeation (as an index of permeability) to observe the changes of intestinal barrier function. The treatment ofF. Arctiiincreased TEER value and decreased OVA influx on Caco-2 cell monolayers. Furthermore, we found that arctigenin as an active component ofF. Arctiiincreased TEER value and reduced permeability of OVA from apical to the basolateral side but not arctiin. In the present study, we revealed thatF. Arctiicould enhance intestinal barrier function, and its active component was an arctigenin on the functionality. We expect that the arctigenin fromF. Arctiicould contribute to prevention of inflammatory, allergic, and infectious diseases by reinforcing intestinal barrier function.

Interactions Between Salmonella Typhimurium, Enteropathogenic Escherichia Coli (EPEC), and Host Epithelial Cells

1995 ◽  
Vol 9 (1) ◽  
pp. 31-36 ◽  
Author(s):  
B.B. Finlay
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Salmonella Typhimurium ◽  
Host Cell ◽  
Inositol Phosphate ◽  
Enteric Pathogens ◽  
Host Protein ◽  
Host Cells ◽  
Enteropathogenic Escherichia Coli ◽  
Sequence Of Events

The interactions that occur between pathogenic micro-organisms and their host cells are complex and intimate. We have used two enteric pathogens, Salmonella typhimurium and enteropathogenic Escherichia coli (EPEC), to examine the interactions that occur between these organisms and epithelial cells. Although these are enteric pathogens, the knowledge and techniques developed from these systems may be applied to the study of dental pathogens. Both S. typhimurium and EPEC disrupt epithelial monolayer integrity, although by different mechanisms. Both pathogens cause loss of microvilli and re-arrangement of the underlying host cytoskeleton. Despite these similarities, both organisms send different signals into the host cell. EPEC signal transduction involves generation of intracellular calcium and inositol phosphate fluxes, and activation of host tyrosine kinases that results in tyrosine phosphorylation of a 90-kDa host protein. Bacterial mutants have been identifed that are deficient in signaling to the host. We propose a sequence of events that occur when EPEC interacts with epithelial cells. Once inside a host cell, S. typhimurium remains within a vacuole. To define some of the parameters of the intracellular environment, we constructed genetic fusions of known genes with lacZ, and used these fusions as reporter probes of the intracellular vacuolar environment. We have also begun to examine the bacterial and host cell factors necessary for S. typhimurium to multiply within epithelial cells. We found that this organism triggers the formation of novel tubular lysosomes, and these structures are linked with intracellular replication.

Extrusion of actin-positive strands from HEp-2 and Int 407 cells caused by outer membrane preparations of enteropathogenicEscherichia coliand specific attachment of wild type bacteria to the strands

2001 ◽  
Vol 47 (8) ◽  
pp. 727-734 ◽  
Author(s):  
Sukumaran Sunil Kumar ◽  
Vasantha Malladi ◽  
Krishnan Sankaran ◽  
Richard Haigh ◽  
Peter Williams ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Membrane Proteins ◽  
Outer Membrane ◽  
Outer Membrane Proteins ◽  
Three Dimensional ◽  
Secretory Proteins ◽  
Enteropathogenic Escherichia Coli ◽  
Wild Type ◽  
Cytopathic Effects ◽  
Cytoskeletal Elements

Enteropathogenic Escherichia coli (EPEC) causes persistent infantile diarrhoea. This nontoxigenic E. coli exhibits a complicated pathogenic mechanism in which its outer membrane proteins and type III secretory proteins damage intestinal epithelium and cause diarrhoea. In accordance with this, our previous study using HEp-2 cells demonstrated cytopathic effects caused by cell-free outer membrane preparations of EPEC. In this study, we report the extrusion of actin-positive strands from HEp-2 and Int 407 cells when treated with outer membrane preparations. An interesting observation of this work, perhaps relevant to the characteristic localized three-dimensional colony formation of EPEC, is the attachment of a wild type EPEC strain to these actin-positive strands.Key words: enteropathogenic Escherichia coli, actin, outer membrane proteins, cytoskeletal elements.

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.

PGE2promotes Ca2+-mediated epithelial barrier disruption through EP1and EP4receptors in Caco-2 cell monolayers

2010 ◽  
Vol 299 (2) ◽  
pp. C324-C334 ◽  
Author(s):  
M. José Rodríguez-Lagunas ◽  
Raquel Martín-Venegas ◽  
Juan José Moreno ◽  
Ruth Ferrer
Keyword(s):  
Signaling Pathways ◽  
Barrier Function ◽  
Epithelial Barrier ◽  
Intestinal Epithelial ◽  
Epithelial Barrier Function ◽  
Cell Monolayers ◽  
Intracellular Ca ◽  
Inflammatory Processes ◽  
Zona Occludens

We recently demonstrated that PGE2induces the disruption of the intestinal epithelial barrier function. In the present study, our objectives were to study the role of PGE2receptors (EP1–EP4) and the signaling pathways involved in this event. Paracellular permeability (PP) was assessed in differentiated Caco-2 cell cultures from d-mannitol fluxes and transepithelial electrical resistance (TER) in the presence of different PGE2receptor agonists (carbacyclin, sulprostone, butaprost, ONO-AE1-259, ONO-AE-248, GR63799, and ONO-AE1-329) and antagonists (ONO-8711, SC-19220, AH-6809, ONO-AE3-240, ONO-AE3-208, and AH-23848). The results indicate that EP1and EP4but not EP2and EP3might be involved in PP regulation. These effects were mediated through PLC-inositol trisphosphate (IP3)-Ca2+and cAMP-PKA signaling pathways, respectively. We also observed an increase in intracellular Ca2+concentration ([Ca2+]i) strengthened by cAMP formation indicating a cross talk interaction of these two pathways. Moreover, the participation of a conventional PKC isoform was shown. The results also indicate that the increase in PP may be correlated with the redistribution of occludin, zona occludens 1 (ZO-1), and the perijunctional actin ring together with an increase in myosin light chain kinase activity. Although the disruption of epithelial barrier function observed in inflammatory bowel disease (IBD) patients has been traditionally attributed to cytokines, the present study focused on the role of PGE2in PP regulation, as mucosal levels of this eicosanoid are also increased in these inflammatory processes.

The role of caspase-3 in lipopolysaccharide-mediated disruption of intestinal epithelial tight junctions

2006 ◽  
Vol 84 (10) ◽  
pp. 1043-1050 ◽  
Author(s):  
Alex C. Chin ◽  
Andrew N. Flynn ◽  
Jason P. Fedwick ◽  
Andre G. Buret
Keyword(s):  
Escherichia Coli ◽  
Tight Junctions ◽  
Intestinal Permeability ◽  
Barrier Function ◽  
Caspase 3 ◽  
Parp Cleavage ◽  
Intestinal Epithelial ◽  
Epithelial Permeability ◽  
Epithelial Monolayers

The mechanisms responsible for microbially induced epithelial apoptosis and increased intestinal permeability remain unclear. This study assessed whether purified bacterial lipopolysaccharide (LPS) increases epithelial apoptosis and permeability and whether these changes are dependent on caspase-3 activation. In nontumorigenic epithelial monolayers, Escherichia coli O26:B6 LPS increased apoptosis, as shown by nuclear breakdown, caspase-3 activation, and PARP cleavage, and induced disruption of tight junctional ZO-1. Apical, but not basolateral, exposure to LPS increased epithelial permeability. Addition of a caspase-3 inhibitor abolished the effects of LPS. The findings describe a novel mechanism whereby apical LPS may disrupt epithelial tight junctional ZO-1 and barrier function in a caspase-3-dependent fashion.

scholarly journals Enteropathogenic Escherichia coli Activates Ezrin, Which Participates in Disruption of Tight Junction Barrier Function

2001 ◽  
Vol 69 (9) ◽  
pp. 5679-5688 ◽  
Author(s):  
Ivana Simonovic ◽  
Monique Arpin ◽  
Athanasia Koutsouris ◽  
Holly J. Falk-Krzesinski ◽  
Gail Hecht
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
Cytoskeletal Proteins ◽  
Dominant Negative ◽  
Intestinal Epithelial ◽  
E Coli ◽  
Membrane Cytoskeleton ◽  
Intestinal Pathogen ◽  
Response Expression

ABSTRACT Enteropathogenic Escherichia coli (EPEC) is an important human intestinal pathogen, especially in infants. EPEC adherence to intestinal epithelial cells induces the accumulation of a number of cytoskeletal proteins beneath the bacteria, including the membrane-cytoskeleton linker ezrin. Evidence suggests that ezrin can participate in signal transduction. The aim of this study was to determine whether ezrin is activated following EPEC infection and if it is involved in the cross talk with host intestinal epithelial cells. We show here that following EPEC attachment to intestinal epithelial cells there was significant phosphorylation of ezrin, first on threonine and later on tyrosine residues. A significant increase in cytoskeleton-associated ezrin occurred following phosphorylation, suggesting activation of this molecule. Nonpathogenic E. coli and EPEC strains harboring mutations in type III secretion failed to elicit this response. Expression of dominant-negative ezrin significantly decreased the EPEC-elicited association of ezrin with the cytoskeleton and attenuated the disruption of intestinal epithelial tight junctions. These results suggest that ezrin is involved in transducing EPEC-initiated signals that ultimately affect host physiological functions.

scholarly journals Novel effects of the prototype translocating Escherichia coli, strain C25 on intestinal epithelial structure and barrier function

2005 ◽  
Vol 7 (12) ◽  
pp. 1782-1797 ◽  
Author(s):  
Mehri Zareie ◽  
Jason Riff ◽  
Kevin Donato ◽  
Derek M. McKay ◽  
Mary H. Perdue ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Barrier Function ◽  
Coli Strain ◽  
Intestinal Epithelial ◽  
Epithelial Structure
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