Glutathione oxidation and PTPase inhibition by hydrogen peroxide in Caco-2 cell monolayer.
The role of H(2)O(2) and protein thiol oxidation in oxidative stress-induced epithelial paracellular permeability was investigated in Caco-2 cell monolayers. Treatment with a H(2)O(2) generating system (xanthine oxidase + xanthine) or H(2)O(2) (20 microM) increased the paracellular permeability. Xanthine oxidase-induced permeability was potentiated by superoxide dismutase and prevented by catalase. H(2)O(2)-induced permeability was prevented by ferrous sulfate and potentiated by deferoxamine and 1,10-phenanthroline. GSH, N-acetyl-L-cysteine, dithiothreitol, mercaptosuccinate, and diethylmaleate inhibited H(2)O(2)-induced permeability, but it was potentiated by 1,3-bis(2-chloroethyl)-1-nitrosourea. H(2)O(2) reduced cellular GSH and protein thiols and increased GSSG. H(2)O(2)-mediated reduction of GSH-to-GSSG ratio was prevented by ferrous sulfate, GSH, N-acetyl-L-cysteine, diethylmaleate, and mercaptosuccinate and potentiated by 1,10-phenanthroline and 1, 3-bis(2-chloroethyl)-1-nitrosourea. Incubation of soluble fraction of cells with GSSG reduced protein tyrosine phosphatase (PTPase) activity, which was prevented by coincubation with GSH. PTPase activity was also lower in H(2)O(2)-treated cells. This study indicates that H(2)O(2), but not O(2)(-). or.OH, increases paracellular permeability of Caco-2 cell monolayer by a mechanism that involves oxidation of GSH and inhibition of PTPases.
Department of Pediatrics, Medical University of South Carolina, Charleston 29425, USA.
R K
RK
Rao
L
L
Li
R D
RD
Baker
S S
SS
Baker
A
A
Gupta
D000111:Acetylcysteine / Q000494:pharmacology; D018906:Antineoplastic Agents, Alkylating / Q000494:pharmacology; D018938:Caco-2 Cells; D002330:Carmustine / Q000494:pharmacology; D002374:Catalase / Q000494:pharmacology; D002463:Cell Membrane Permeability / Q000187:drug effects / Q000502:physiology; D002614:Chelating Agents / Q000494:pharmacology; D003676:Deferoxamine / Q000494:pharmacology; D016166:Free Radical Scavengers / Q000494:pharmacology; D005978:Glutathione / Q000378:metabolism* / Q000494:pharmacology; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000166:cytology; D007501:Iron / Q000494:pharmacology; D008298:Maleates / Q000494:pharmacology; D016877:Oxidants / Q000494:pharmacology*; D010084:Oxidation-Reduction; D010618:Phenanthrolines / Q000494:pharmacology; D017027:Protein Tyrosine Phosphatases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D013438:Sulfhydryl Compounds / Q000378:metabolism; D013482:Superoxide Dismutase / Q000494:pharmacology; D013870:Thiomalates / Q000494:pharmacology; D019108:Tight Junctions / Q000201:enzymology; D014801:Vitamin A / Q000494:pharmacology; D014810:Vitamin E / Q000494:pharmacology
D018906:Antineoplastic Agents, Alkylating; D002614:Chelating Agents; D016166:Free Radical Scavengers; D008298:Maleates; D016877:Oxidants; D010618:Phenanthrolines; D013438:Sulfhydryl Compounds; D013870:Thiomalates; D014801:Vitamin A; D014810:Vitamin E; C046062:2-thiomalic acid; D006861:Hydrogen Peroxide; D007501:Iron; D002374:Catalase; D013482:Superoxide Dismutase; D011505:Protein-Tyrosine Kinases; D017027:Protein Tyrosine Phosphatases; C014476:diethyl maleate; D005978:Glutathione; D003676:Deferoxamine; D002330:Carmustine; D000111:Acetylcysteine