Piceatannol Attenuates High Glucose-induced Podocyte Injury Via Nrf2-mediated Inhibition Of NLRP3 Inflammasome Activation

Objective: We established an in vitro model of DN by treating podocyte with high glucose(HG),and explored whether piceatannol can attenuate HG-induced podocyte injury.Furthermore,its underlying mechanism was investigated,which provide an experimental basis for the development of new drugs.Methods: In terms of the influence of Piceatannol on the injury of podocytes under the condition of high glucose,we divided the in vitro culture of podocytes into the following five groups: control group(NG;5.6 mM D-glucose),high glucose group(HG;30 mM D-glucose),HG + piceatannol(5 μM)group,HG + piceatannol(10 μM)group and HG + piceatannol(20 μM)group.CCK-8 kit,TUNEL apoptosis assay kit,ELISA kits and ROS assay kit were applied to assess the effects of piceatannol on cell viability,apoptosis,inflammation and oxidative stress in podocytes treated with HG.In terms of the possible molecular mechanism of Piceatannol to reduce the injury of podocytes under the condition of high glucose,we divided the in vitro culture of mouse podocytes into the following five groups:control group(NG;5.6 mM D-glucose),high glucose group(HG;30 mM D-glucose),HG + piceatannol(20 μM)group,HG + piceatannol(20 μM)+sh-NC group and HG + piceatannol(20 μM)+sh-Nrf2 group,Real-time fluorescence quantitative PCR was used to detect Nrf2 gene expression after transfection,and caspase-1 activity was detected by caspase-1 activity detection kit,Western blot was performed to determine the protein levels of Nrf2,NLRP3,ASC and cleaved caspase-1.Results: Compared with the control group,piceatannol treatment reduced the viability of podocytes in a dose-dependent manner.Piceatannol treatment inhibited the apoptosis and promoted the viability of podocytes treated with HG,in a dose-dependent manner.Piceatannol treatment markedly decreased the levels of IL-1β,IL-18,TNF-α and TGF-β1 in podocytes treated with HG.Meanwhile,Piceatannol markedly decreased the levels of ROS and promoted nuclear translocation of Nrf2 in podocytes under HG condition.Piceatannol inhibited the activation of NLRP3 inflammasome in podocytes treated with HG by regulating the expression of Nrf2.Furthermore,knockdown of Nrf2 could blocked the protective effect of piceatannol on HG-induced podocytes injury.Conclusion: By promoting nuclear translocation of Nrf2,inhibiting the activation of NLRP3 inflammasome and attenuating HG-induced cell apoptosis,inflammation and oxidative stress,piceatannol attenuates high glucose-induced podocyte injury.