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Helicobacter pylori induces MLCK‐ dependent adherens junction disruption in non‐tumorigenic epithelial monolayers
Author(s) -
O’Connor Pamela M.,
Lapointe Tamia K.,
Fedwick Jason P.,
Buret Andre G.
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.6.a766-c
Subject(s) - adherens junction , myosin light chain kinase , helicobacter pylori , cadherin , microbiology and biotechnology , myosin , phosphorylation , biology , catenin , population , chemistry , cell , wnt signaling pathway , signal transduction , biochemistry , medicine , genetics , environmental health
H. pylori (Hp) infects half of the human population and can cause gastritis, gastroduodenal ulcers, and gastric cancer. The ability of Hp to alter epithelial cell‐cell adhesion may influence the clinical outcome of infection. Disruption of adherens junction (AJ) proteins E‐cadherin and β–catenin have been implicated in carcinogenesis. The effects of Hp on the AJ and whether such changes may involve a known regulator of epithelial barrier function, myosin‐light chain kinase (MLCK), are unclear. Aim: The aim of this study was to characterize the effects of Hp on the AJ in non‐tumorigenic epithelial cell (SCBN) monolayers, and to examine the role of MLCK in these effects. Results: Western blotting revealed increased levels of phosphorylated myosin light chain (MLC) in cells challenged with Hp strain SS1 while myosin light chain‐2 levels remained unchanged. Immunocytochemistry demonstrated disruption of membranous E‐cadherin and redistribution of β–catenin in Hp infected monolayers, but not in controls. Immunoblotting revealed a time‐dependent, Hp‐induced decrease in E‐cadherin expression. Pre‐treatment with a selective MLCK inhibitor (ML‐9) prevented these effects. Conclusion: Hp‐induced phosphorylation of epithelial MLC is associated with AJ disruptions in non‐tumorigenic epithelial cells. These alterations of E‐cadherin and β–catenin are regulated, at least in part, by MLCK