Homocysteine inhibits activity of eNOS in endothelial cells from human umbilical vein

Objective To study the mechanism of homocysteine(Hcy) on eNOS activity in human umbilical vein endothelial cells(HUVECs).Methods HUVECs were collected and cultured.Then the second passage of HUVECs were cultured with different Hcy concentrations for different times.The expression of HSP90,Akt,caveolin-1,eNOS,P-eNOS proteins were detected by Western blot and the expression of Caveolin-1,eNOS,DDAH mRNA by RT-PCR.Results Compared with control group,both in base and calcium ionophore activated state,the expression of Caveolin-1 group increased obviously(P0.05) in concentration and time-dependent manner,but the expression of Akt showed decreasing(P0.05).The expression of eNOS did not change significantly.There was no difference in the expression of HSP90,eNOS,P-eNOS protein and mRNA among every group.DDAH mRNA among every group too.Conclusions There was no relationship between decreasing activity of eNOS induced by Hcy and eNOS expression,Hcy probably can increase the association of Caveolin-1 and eNOS by enhancing the expression of Caveolin-1,and reduce the complex formation of Caveolin-1,Akt,Caveolin-1 in HUVEC both in base and activated state,which can decrease the activity of eNOS.