Reducing‐Autophagy Derived Mitochondrial Dysfunction during Resveratrol Promotes Fibroblast‐Like Synovial Cell Apoptosis

ABSTRACT In rheumatoid arthritis patients, the fibroblast‐like synovial cells (FLS) growth is not controlled normally, but is similar to the tumor cells proliferation in histology. Our previous studies have shown that resveratrol inhibits the proliferation of FLS and promotes FLS apoptosis. However, the molecular mechanisms involved in resveratrol‐induced FLS apoptosis have not been determined yet. Here, we showed that the FLS cell viability (following pretreatment with 5 µM H2O2 for 24 hr) exhibited better proliferation performance than at other concentrations via the CCK‐8 assay. The cell apoptotic rate increased with the increasing concentration of resveratrol (0, 40, 80, 160, 320 μM), as detected by TdT‐mediated dUTP nick‐end labeling (TUNEL) staining and western blotting. Furthermore, the expression level of autophagy‐related proteins (LC3A/B, ATG‐5) decreased with the increased concentration of resveratrol, as determined by immunofluorescence and western blot analysis. We also showed that resveratrol induced FLS mitochondrial morphology change. Moreover, mitochondrial function detection showed that the mitochondrial membrane potential was lost with the increased concentration of resveratrol as examined by the JC‐1 assay. The production of ATP in cells was positively and negatively correlated with the resveratrol concentration. Simultaneously, the intracellular calcium release and calcium influx decreased gradually with the increase in resveratrol concentration. Therefore, we proposed that resveratrol can reduce the level of autophagy in FLS. The decrease in the autophagy level can lead to the accumulation of reactive oxygen species, which may result in mitochondrial dysfunction and promotion of FLS apoptosis. Anat Rec, 301:1179–1188, 2018. © 2018 Wiley Periodicals, Inc.