title: Pro-survival effects of repetitive low-grade oxidative stress are inhibited by simultaneous exposure to Resveratrol.
abstract: V79 lung fibroblasts were subjected to repetitive oxidative stress in culture through exposures to 30 microM H(2)O(2) for 4 weeks. Repetitively stressed cells were found to be significantly resistant to apoptosis-inducing agent such as ultraviolet radiation (UVR). Concurrent treatment with Resveratrol completely restored the normal apoptotic response after UVR. p38MAPK became dually phosphorylated during the stress period. Akt also became phosphorylated on Ser(473) in cells subjected to repetitive oxidative stress. In these cells, NFkappaB p65 became phosphorylated and appreciable nuclear localization of p65 was observed. NFkappaB transcriptional activity also became augmented during repetitive stress. Treatment of the repetitively stressed cells concurrently with Resveratrol or SB203580, a p38MAPK inhibitor, robustly blocked activation of p38MAPK, NFkappaB transcriptional activity, phosphorylation and nuclear localization of p65, and Akt phosphorylation. Pre-exposure to short interfering RNA (si RNA) to p38MAPK, resulted in a blockage of the Akt and NFkappaB p65 phosphorylation. However, inhibition of Akt activity through PI3 kinase inhibitor LY294002 did not result in obstruction of p38MAPK phosphorylation by H(2)O(2). Also, Resveratrol was effective as an antioxidant in counteracting a rise in reactive oxygen species (ROS) and p38MAPK activation by H(2)O(2) was completely blocked by antioxidant N-acetyl cysteine (NAC). We conclude that Resveratrol acts as an antioxidant and completely reverses the anti-apoptotic effects of repetitive stress by blocking oxidative stress-induced p38MAPK activation which is the key regulatory step for the activation of down-stream survival elements Akt and NFkappaB.
authors.affiliation: Crystallography & Molecular Biology Division, Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, Kolkata 700064, India.
authors.forename: Prabir Kumar
authors.initials: PK
authors.lastname: Chakraborty
authors.forename: Soumyajit Banerjee
authors.initials: SB
authors.lastname: Mustafi
authors.forename: Sanghamitra
authors.initials: S
authors.lastname: Raha
mesh_terms: D000818:Animals; D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology*; D015153:Blotting, Western; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects* / Q000502:physiology*; D006224:Cricetinae; D053938:DNA Fragmentation; D024202:Electrophoretic Mobility Shift Assay; D005347:Fibroblasts / Q000187:drug effects / Q000502:physiology; D005434:Flow Cytometry; D015870:Gene Expression / Q000187:drug effects; D008168:Lung / Q000166:cytology / Q000187:drug effects; D018613:Microscopy, Confocal; D016328:NF-kappa B / Q000235:genetics; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology*; D034741:RNA, Small Interfering / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000378:metabolism; D000077185:Resveratrol; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D013267:Stilbenes / Q000494:pharmacology*; D014157:Transcription Factors / Q000187:drug effects / Q000502:physiology; D014162:Transfection; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D016588:Anticarcinogenic Agents; D000975:Antioxidants; D016328:NF-kappa B; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species; D013267:Stilbenes; D014157:Transcription Factors; D048051:p38 Mitogen-Activated Protein Kinases; D000077185:Resveratrol