Resveratrol decreases FoXO protein expression through PI3K-Akt-dependent pathway inhibition in H2O2-treated synoviocytes

The aim of this study was to investigate the effects of resveratrol (Res) on hydrogen peroxide (H2O2)-treated fibroblast-like synoviocytes (FLSs) in vitro. We studied the phosphoinositide 3-kinase (PI3K)-Akt pathway inhibition-mediated effects of Res on forkhead box O (FoXO) mRNA expression levels. FLS viability was determined by Cell Counting Kit-8 (CCK-8) assay, and FLS apoptosis was measured by terminal deoxyribo nucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining and flow cytometry. FoXO1, FoXO3 and FoXO4 mRNA expression levels in FLSs were determined by RT-PCR, and p-Akt, Akt, p-FoXO1, FoXO1, p-FoXO3, FoXO3, Bcl-2 and Bax protein expression levels were determined by western blotting. Our results showed that low H2O2 concentrations (20 μM) can promote FLS growth and that Res significantly inhibited FLS activity. Moreover, Res significantly increased the number of apoptotic cells and the ratio of Bax/Bcl-2 protein expression in the group treated with Res compared with the group treated with H2O2 and LY294002, a PI3K inhibitor. Res also decreased FoXO1, FoXO3 and FoXO4 mRNA expression levels and p-Akt/Akt, p-FoXO1/FoXO1, p-FoXO3/FoXO3 protein expression levels. Taken together, these findings indicate that Res can induce apoptosis in H2O2-treated FLSs in part by inhibiting the PI3K-Akt signaling pathway