Influence of estrogen on TNFα induced apoptosis of endothelial cells

Obsjective To investigate the effects of 17β estradiol(E 2) and tumour necrosis factor alpha (TNFα)on the apoptosis of cultured human umbilical vein endothelial cells(HUVEC).Methods HUVEC were divided into four groups:control group,TNFα(40 μg/L) group,TNFα(40 μg/L) with E 2(1 μmol/L) group and E 2(10 μmol/L) group.Cells were gained after all groups were cultured for 24 hours.The apoptosis was assessed by flow cytometry and the expression of bcl 2 protein was measured by immunohistochemical method.Results Compared with control,HUVEC apoptosis increased significantly (P0.01) and bcl 2 protein expression decreased in TNFα (40 μg/L) group.17β estradiol (1 μmol/L,10 μmol/L) reduced the apoptosis induced by TNFα(P0.001) and dincreased the expression of bcl 2 protein.Conclusions 17β Estradiol could downregulate the TNFα induced apoptosis of HUVEC and maintain integrity of endothelium,suggesting that estrogen may possess antiatherosclerotic ability.