ABSTRACT
Objective:Pin1 plays an important role in the pathogenesis of cardiovascular disease,our study aims to investigate the effects of Pin1 silencing by siRNA on H9c2 apoptosis induced by hypoxia/reoxygenation.Methods:H9c2 cells were cultured and subjected to a hypoxia/reoxygenation (H/R) condition in vitro,mimicking ischemic/reperfusion injury in vivo.The mRNA and protein expression of Pin1 were detected by RT-qPCR and Western blot.H9c2 cells were divided into control group,H/R group,H/R+Pin1 siRNA group,H/R+scramble siRNA group.MTT and flow cytometry with Annexin V-FITC/PI staining were respectively performed to detect cell viability and apoptosis.The expression of Bax and Bcl-2 were measured by Western blot.The activity of Caspase-3 was detected by automatic biochemistry analytic instrument.Results:The mRNA and protein levels of Pin1 were highly expressed in the cells of H/R group.Transfection with Pin1 siRNA strikingly inhibited the expression of Pin1.Compared with H/R group,Pin1 siRNA markedly increased cell viability,decreased the cell apoptosis and the Caspase-3 activity.Furthermore,the increased Bcl-2,decreased Bax and the ratio of Bcl-2 to Bax were observed in Pin1 siRNA group (P<0.05) compared with H/R group.Conclusion:Downregulation of Pin1 protects hypoxia/reoxygenation-injured H9c2 cells from apoptosis,which is possibly through the upregulation of Bcl-2 and downregulation of Bax and Caspase-3 activity.