Resveratrol protects against apoptosis induced by interleukin-1β in nucleus pulposus cells via activating mTOR/caspase-3 and GSK-3β/caspase-3 pathways

OBJECTIVE  The purpose of this study was to investigate the specific downstream signaling pathway mediated by PI3K/Akt in resveratrol (RES) anti-apoptosis of NPCs. MATERIAL AND METHODS Human nucleus pulposus cells (NPCs) were cultured and divided into six groups. IL-1β was used to induce apoptosis and RES inhibit apoptosis. FACS analysis was used to test apoptotic incidence of NPCs, CCK-8 assay was performed to detect cell viability, The expression level of caspase-3 mRNA was detected by RT-qPCR, and protein levels were determined by western blot. RESULTS  Flow cytometry analysis showed that IL-1β increased the apoptosis rate of nucleus pulposus cells in each group, and RES significantly decreased the apoptosis rate, while  rapamycin (RAPA) and SB216763 inhibited the effect of RES and increased the apoptosis rate again. Similarly, CCK-8 showed that IL-1β decreased activity of nucleus pulposus cells in each group, while RES increased cell activity, PAPA and SB216763 inhibited the effect of RES and decreased cell activity. RT-qPCR results showed IL-1β significantly increased the level of caspase-3 expression, but it was significantly decreased by using RES, RAPA and SB216763 respectively attenuate effects of RES. Western blot results showed that activated caspase-3 was inhibited by RES effect, and was up-regulated again after the addition of RAPA and SB216763. In addition, p-mTOR and p-GSK-3β were up-regulated by RES and down-regulated by RAPA and SB216763. CONCLUSION  RES can inhibit apoptosis induced by IL-1β in human NPCs. PI3K/Akt/mTOR/caspase-3 and PI3K/Akt/GSK-3β/caspase-3 pathway are potential mechanism underlying this process.