Effects of PCSK9 siRNA on Bax,Bcl-2 Expression in THP-1 Derived Macrophages Apoptosis Induced by ox-LDL

Aim To explore the effect of PCSK9 siRNA on Bax,Bcl-2 expression in THP-1 derived macrophages apoptosis induced by ox-LDL. Methods Cells were incubated with varied concentrations of ox-LDL for different time.Western blot were conducted to detect the expression of Bax and Bcl-2.The siRNAs for PCSK9 were designed and synthesized,then THP-1 macrophages were transfected with PCSK9 siRNA(30,50,80 nmol/L) for 24 h and then a high level of ox-LDL(80 μg/mL) for an additional 48-hr.Bax,Bcl-2 protein levels were measured by Western blot and apoptosis was measured with Hoechst 33258 staining. Results ox-LDL(20,40,60,80 μg/mL) increased Bax expression in a dose-dependent manner,but inversely decreased Bcl-2 expression.Furthermore,80 μg/mL ox-LDL increased Bax expression in a time-dependent manner,but inversely decreased Bcl-2 expression.However,PCSK9 siRNA attenuated ox-LDL-induced up-regulation of Bax,down-regulation of Bcl-2,and THP-1 cell apoptosis in a dose-dependent manner. Conclusion The effect of PCSK9-siRNA aganist ox-LDL-induced THP-1 cell apoptosis is associated with down-regulating of Bax and up-regulating of Bcl-2.