Effect of lentivirus-mediated overexpression or silencing of MnSOD on apoptosis of resveratrol-treated fibroblast-like synoviocytes in rheumatoid arthritis.

Fibroblast-like synoviocytes in rheumatoid arthritis (RA-FLSs) play a key role in cartilage destruction. We previously found that resveratrol (Res) could promote FLSs apoptosis in adjuvant arthritis rats, but the underlying mechanism was unclear. According to our latest study, Res can suppress the expression of mitochondrial superoxide dismutase (MnSOD) and RA-FLSs proliferation. It was associated with elevated mitochondrial reactive oxygen species levels. Therefore, we hypothesized that Res-mediated RA-FLSs apoptosis might occur via the MnSOD- mitochondrial reactive oxygen species pathway. RA-FLSs were infected with lentiviruses and screened with puromycin at a concentration of 8 µg/ml. We divided the RA-FLSs into four groups: a control group, a negative control (NC) group, a MnSOD overexpression group, and a MnSOD RNAi group. The four groups of RA-FLSs were tested using confocal laser scanning microscopy, CCK-8 assays, flow cytometry, and western blotting were conducted to determine the involvement of the MnSOD-mitochondrial reactive oxygen species pathway. Compared with the NC group, the MnSOD overexpression group treated with different concentrations of Res (0, 25, 50, 100, or 200 μM) and 5 μM H2O2 showed reduced levels of mitochondrial reactive oxygen species, increased B-cell-lymphoma-2 (Bcl-2), reduced Bcl-2 Associated X protein (Bax), and fewer apoptotic cells. The MnSOD RNAi group showed the opposite results. Thus, we concluded that Res could facilitate RA-FLSs apoptosis by regulating MnSOD expression and mitochondrial reactive oxygen species levels. Our findings show a novel mechanism for the beneficial effects of Res, especially in relation to the MnSOD-mitochondrial reactive oxygen species signaling pathway in RA.