title: Resveratrol up-regulates SIRT1 and inhibits cellular oxidative stress in the diabetic milieu: mechanistic insights.
abstract: Several lines of evidence support a role for oxidative stress in diabetic complications. Diabetic patients have increased O(2)(-) production in monocytes. Loss of SIRT1 activity may be associated with metabolic diseases such as diabetes. Several studies have shown that SIRT1 can regulate mammalian FOXO transcription factors through direct binding and/or deacetylation. However, interactions between SIRT1 and FOXO under diabetic conditions are unclear. The phytochemical resveratrol has recently gained attention for its protection against metabolic disease. Resveratrol has been shown to increase mitochondrial function by activating SIRT1. In this study, we tested the protective effect of resveratrol on cellular oxidative stress through the SIRT1-FOXO pathway under high-glucose conditions. Human monocytic (THP-1) cells were cultured in the presence of mannitol (osmolar control) or normoglycemic (NG, 5.5 mmol/l glucose) or hyperglycemic (HG, 25 mmol/l glucose) conditions in absence or presence of resveratrol (3 and 6 μmol/l) for 48 h. We first examined SIRT1 activity and oxidative stress in monocytes of Type 1 diabetes mellitus (T1DM) patients compared with healthy controls. In T1DM patients, monocytic SIRT1 expression was significantly decreased and p47phox expression was increased compared with controls. Under HG in vitro, SIRT1 and FOXO3a were significantly decreased compared with NG, and this was reversed by resveratrol treatment, concomitant with reduction in HG-induced superoxide production and p47phox. Under HG, SIRT1 small interfering RNA (siRNA) inhibited FOXO3a, and there was no beneficial effect of resveratrol in siRNA-treated HG-induced cells. Thus, resveratrol decreases HG-induced superoxide production via up-regulation of SIRT1, induction of FOXO3a and inhibition of p47phox in monocytes.
authors.affiliation: Department of Pathology and Laboratory Medicine, University of California, Davis, Medical Center, Sacramento, CA 95817, USA.
authors.forename: Jung-Mi
authors.initials: JM
authors.lastname: Yun
authors.forename: Alexander
authors.initials: A
authors.lastname: Chien
authors.forename: Ishwarlal
authors.initials: I
authors.lastname: Jialal
authors.forename: Sridevi
authors.initials: S
authors.lastname: Devaraj
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D002460:Cell Line; D003922:Diabetes Mellitus, Type 1 / Q000188:drug therapy / Q000378:metabolism*; D000071316:Forkhead Box Protein O3; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D009000:Monocytes / Q000378:metabolism; D019255:NADPH Oxidases / Q000235:genetics / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects*; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D000077185:Resveratrol; D056564:Sirtuin 1 / Q000235:genetics / Q000378:metabolism*; D013267:Stilbenes / Q000494:pharmacology*; D013481:Superoxides / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D000975:Antioxidants; C499517:FOXO3 protein, human; D000071316:Forkhead Box Protein O3; D051858:Forkhead Transcription Factors; D034741:RNA, Small Interfering; D013267:Stilbenes; D013481:Superoxides; D019255:NADPH Oxidases; C060505:neutrophil cytosolic factor 1; C447939:SIRT1 protein, human; D056564:Sirtuin 1; D000077185:Resveratrol