Resveratrol induces apoptosis MH7A human rheumatoid arthritis synovial cells in a sirtuin 1-dependent manner

Resveratrol, a phytoalexin, reduced the viability of MH7A cells, a human rheumatoid arthritis synovial cell line. In the apoptosis assay, resveratrol increased TUNEL-positive cells and stimulated H2A.X phosphorylation. Resveratrol disrupted mitochondrial membrane potentials in MH7A cells and stimulated cytochrome c release from the mitochondria to the cytosol. Resveratrol activated caspase-3 and caspase-9 but not caspase-8 in MH7A cells. Resveratrol upregulated the expression of the NAD-dependent deacetylase sirtuin 1 mRNA and downregulated the expression of the Bcl-X_L mRNA, and resveratrol-induced MH7A cell death, mitochondrial damage, and caspase-3/-9 activation were prevented by sirtinol, an inhibitor of sirtuin 1. The results of the present study show that resveratrol induces MH7A cell apoptosis by activating caspase-9 and the effector caspase-3 along mitochondrial disruption as a result of reduced Bcl-X_L expression, allowing cytochrome c release from the mitochondria into the cytosol, in a sirtuin 1-dependent manner. This suggests that resveratrol could suppress hyperplasia of synovial cells, a critical factor of rheumatoid arthritis.