Glutathione depletion inhibits oxidant-induced activation of nuclear factor-kappa B, AP-1, and c-Jun/ATF-2 in cultured guinea-pig gastric epithelial cells.
The aim of this study was to reveal the role of intracellular glutathione in the oxidative stress responses of gastric epithelial cells. Metabolic radiolabeling with L-[35S]methionine and analysis of synthesized proteins by gel electrophoresis and fluorography showed that upon exposure to hydrogen peroxide (H2O2) or diamide, primary cultures of guinea-pig gastric epithelial cells rapidly induced several undefined proteins, as well as heat shock proteins. When intracellular glutathione was depleted to less than 10% of the control value by treatment with buthionine-[S,R]-sulfoximine, these inductions were completely inhibited. Gel mobility shift assay demonstrated that H2O2 and diamide rapidly activated nuclear factor-kappa B (NF-kappaB), and diamide activated activator protein (AP)-1, and c-Jun/activating transcription factor (ATF)-2, suggesting that the response may be coupled to these reduction-oxidation (redox)-sensitive transcription factors, as well as heat shock transcription factor 1. The activations of NF-kappaB, AP-1, and c-Jun/ATF-2 by the oxidants did not occur in glutathione-depleted cells. Northern blot analysis showed that glutathione depletion markedly or completely suppressed the diamide-induced expression of c-fos and c-jun mRNAs. These results suggest that intracellular glutathione redox may participate in the initiation of oxidative stress responses; thereby, it plays an important role in gastric mucosal defense.
Department of Nutrition, School of Medicine, The University of Tokushima, Japan.
K
K
Rokutan
S
S
Teshima
M
M
Miyoshi
T
T
Kawai
T
T
Nikawa
K
K
Kishi
D051698:Activating Transcription Factor 2; D000818:Animals; D015152:Blotting, Northern; D002478:Cells, Cultured; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism*; D017931:DNA Primers; D004847:Epithelial Cells / Q000378:metabolism*; D005753:Gastric Mucosa / Q000166:cytology / Q000378:metabolism*; D005978:Glutathione / Q000378:metabolism*; D006168:Guinea Pigs; D008297:Male; D016328:NF-kappa B / Q000378:metabolism*; D018384:Oxidative Stress; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism*; D018808:Transcription Factor AP-1 / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*
D051698:Activating Transcription Factor 2; D017362:Cyclic AMP Response Element-Binding Protein; D017931:DNA Primers; D016328:NF-kappa B; D016755:Proto-Oncogene Proteins c-jun; D018808:Transcription Factor AP-1; D014157:Transcription Factors; D005978:Glutathione