title: Chemically induced oxidative stress disrupts the E-cadherin/catenin cell adhesion complex.
abstract: The impact of xenobiotics on intercellular adhesion, a fundamental biological process regulating most, if not all, cellular pathways, has been sparsely investigated. Cell-cell adhesion is regulated in the epithelium primarily by the E-cadherin/catenin complex. To characterize the impact of oxidative stress on the E-cadherin/catenin complex, precision-cut mouse liver slices were challenged with two model compounds for the generation of oxidative stress, diamide (DA; 25-250 microM) or t-butylhydroperoxide (tBHP; 5-50 microM), for 6 h. At the concentrations used, neither compound elicited cytotoxicity, as assessed by intracellular K+ content and leakage of lactate dehydrogenase into the culture media. However, a 25% reduction in non-protein sulfhydryl levels, an indication of oxidative perturbation, was seen in liver slices treated with DA or tBHP. Total protein expression of E-cadherin, beta-, or alpha-catenin was not affected by challenge with DA or tBHP. A decrease of beta-catenin in the SDS-soluble fraction of slices, an indicator of the formation of the adhesion complex, was observed. Additionally, a decrease in beta-catenin interactions with E-cadherin and alpha-catenin, as assessed by immunoprecipitation and Western blot analysis, was seen. Disruption of the E-cadherin/catenin complex by tBHP, but not DA, correlated with enhanced tyrosine phosphorylation of beta-catenin. These results suggest that noncytotoxic oxidative stress disrupts the E-cadherin/catenin cell adhesion complex in precision-cut mouse liver slices.
authors.affiliation: Department of Anesthesiology, College of Medicine, Southwest Environmental Health Sciences Center. University of Arizona, Tucson, USA. parrish@medicine.tamu.edu
authors.forename: A R
authors.initials: AR
authors.lastname: Parrish
authors.forename: J M
authors.initials: JM
authors.lastname: Catania
authors.forename: J
authors.initials: J
authors.lastname: Orozco
authors.forename: A J
authors.initials: AJ
authors.lastname: Gandolfi
mesh_terms: D000818:Animals; D015153:Blotting, Western; D015820:Cadherins / Q000378:metabolism*; D002448:Cell Adhesion / Q000187:drug effects / Q000502:physiology; D002470:Cell Survival / Q000187:drug effects; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D003958:Diamide / Q000494:pharmacology*; D066298:In Vitro Techniques; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008297:Male; D051379:Mice; D018384:Oxidative Stress / Q000187:drug effects*; D019000:Phosphotyrosine / Q000378:metabolism; D011188:Potassium / Q000378:metabolism; D015534:Trans-Activators; D051178:alpha Catenin; D051176:beta Catenin; D020122:tert-Butylhydroperoxide / Q000494:pharmacology*
chemical_list: C495267:CTNNB1 protein, mouse; D015820:Cadherins; C495272:Ctnna1 protein, mouse; D003598:Cytoskeletal Proteins; D015534:Trans-Activators; D051178:alpha Catenin; D051176:beta Catenin; D003958:Diamide; D019000:Phosphotyrosine; D020122:tert-Butylhydroperoxide; D007770:L-Lactate Dehydrogenase; D011188:Potassium