The Effects And Mechanism Of Simvastatin On Proliferation And Apoptosis Of Vascular Endothelial Cell Induced By High Glucose

Objective To observe the effects of different concentrations of SIM on proliferation,NO, ET-1of VEC induced by high glucose; to understand the effects of differentconcentrations of SIM on ROS content,apoptosis rate and levels of phosphorylationJNK of VEC induced by high glucose,and discuss the protective macanism of SIM onVEC.Methods VEC were cultured in vitro complete DMEM medium, VEC in logarithmicgrowth phase were randomly divided into5groups,A group:normal culture group(Glu5.5mmol/l);B group:high glucose group(Glu:33mmol/l);C group:high glucose+SIM(1×10-7mmol/L);D group: high glucose+SIM(1×10-6mmol/L);E group:highglucose+SIM(1×10-5mmol/L).①To detect the change of proliferation of differentconcentrations of SIM under different time-points(6h,12h,18h,24h),and to confirm theoptimum time-point of SIM;②The NO and ET-1levels of coculture supernatants ineach group were measured by nitrate reductase and radioimmunoassay respectively;③To measure ROS content in each group by flow cytometry(FCM) with DCFH-DA;④Tomeasure apoptosis rate in each group by flow cytometry(FCM) with Annexin V/PI;⑤Add F group:high glucose+SP600125(10.0μmol/L),and detect the protein expression ofJNK and p-JNK in every group.Results①Compared to the high glucose group,SIM improved the proliferationinhibition of VEC induced by high glucose significantly(P<0.01),and in aconcentration-dependent manner; the improvement of proliferation inhibition in VEC was most significant at the time-point of18h(P<0.01);②Compared to the normalculture group,the NO level of coculture supernatants declined obviously in high glucose(P<0.01),the ET-1level of coculture supernatants increased obviously in high glucose(P<0.01);compared to the high glucose group,SIM reduced the level of ET-1obviouslyin high glucose group as well as increased the level of NO, and in aconcentration-dependent manner(P<0.05);③Compared to the normal culture group, theROS content increased obviously in high glucose group(P<0.01); compared to the highglucose group,the ROS content in SIM group declined in a concentration-dependentmanner(P<0.05);④Compared to the normal culture group,the apoptosis rate increasedobviously in high glucose group(P<0.01); compared to the high glucose group,theapoptosis rate in SIM group declined in a concentration-dependent manner, there was asignificant difference in medium and high concentration of SIM group（P<0.01）;⑤Compared to the normal culture group, the phosphorylation level of JNK of VEC inhigh glucose group increased obviously(P<0.01); compared to the high glucosegroup,SIM decreased the phosphorylation level of JNK in high glucose group, and in aconcentration-dependent manner(P<0.05); compared to the high glucose group, JNKinhibitor SP600125declined the level of phosphrylation obviously(P<0.05).Conclusion High glucose can inhibit the proliferation of VEC; decline the level of NO,increase the secretion of ET-1; incline the content of ROS, promote apoptosis in VECand upregulate the phosphorylation level of JNK; SIM can improve the above indexes,and in a concentration-dependent manner; after the pretreatment of JNK inhibitorSP600125, the phosphorylation level of JNK declined obviously; SIM may protect VECby inhibiting the phosphorylation level of JNK, blocking the activation of JNK pathway.