The Effects Of Intermittent High Glucose On Cell Apoptosis In HUVECs And Expression Of Caspase-3,Bax And Bcl-2

Objective To investigate the changes of function of human vessel endothelial cells influenced by intermittent high glucose,through observing cell apoptosis and the changes of related signal transduction molecules.Methods The intermittent high glucose model was established in human umbilical vein endothelial cells(HUVEC-12)for 7 days.Flow cytometer(FCM)and fluorescent staining with hoechst33258 were used to detect synergetic apoptosis of HUVEC-12.Western blot was used to detect the protein expression of caspase-3,bax,and bcl-2.Results Cell apoptosis could be induced by both high glucose and intermittent high glucose.The apoptosis rate was higher in the group of intermittent high glucose than that in both groups of high glucose and control(P＜0.05).The inhibitor of caspase-3 could obviously decrease the apoptosis rate induced by intermittent high glucose(P＜0.05). Western blotting analysis showed that,after 7-days culture,bcl-2 protein was significantly decrease in intermittent and high glucose groups compared with control,and even lower in the intermittent glucose condition(P＜0.05).In constant high glucose the proteins of caspase-3 and bax increased,this Phenomenon more evident in intermittent high glucose(P＜0.05).Conclusion The high glucose and intermittent high glucose can induce the apoptosis of HUVECs.However,apoptosis can be enhanced in HUVECs exposed to intermittent,rather than constant high glucose concentration.The effect of high glucose inducing apoptosis not only related to increased expression of caspase-3 and bax,but also related to decreased expression of bcl-2.This process of apoptosis can be inhibited by the specific inhibitor of caspase-3,suggested that activated caspase-3 pathway was involved in this process.