ROLE OF bcl-2 IN APOPTOSIS OF VASCULAR SMOOTH MUSCLE CELLS INDUCED BY NITRIC OXIDE

Objective To explore the effect of bcl 2 in vascular smooth muscle cells(VSMC) apoptosis induced by nitric oxide(NO),we investigated the effect of NO on Bcl 2 protein expression in cultured vascular smooth muscle cells(VSMCs),and effect of Bcl 2 over expression on apoptosis is(VSMCs) induced by NO. Methods Cultured rat VSMCs at passage 5 to 8 were used for experiments,S nitroso N acetypenicillamine(SNAP) was used as NO donor.Cells were preincubated for 24-48 hours in special culture dish with conditioned medium to reach quiescent,and then incubated in conditioned medium containing 0 5 mmol/L SNAP.After 8 to 10 hours,the cells were fixed and Bcl 2 expression was analyzed by ACAS 570 through fluorescent immunochemistry.Vascular smooth muscle cells were transfected with bcl 2 gene through retrovirus to allow overexpression of Bcl 2 in VSMCs.Finally,we observed the apoptosis in normal VSMCs and VSMCs infected with bcl 2. Results SNAP downregulated Bcl 2 expression in VSMCs.PCR and Southern hybridization confirmed the integration of the bcl 2 retrovirus vector into vascular smooth muscle cells genomic DNA.And fluorescence immunohistochemistry confirmed that Bcl 2 protein was overexpressed in VSMCs infected with bcl 2.And ratio of apoptosis become lower in VSMCs infected with bcl 2. Conclusion bcl 2 can inhibit apoptosis of VSMCs induced by SNAP.It is suggested that downregulation of Bcl 2 protein is one of the ways in which SNAP induces VSMCs apoptosis,and apoptosis in VSMCs induced by SNAP is regulated by bcl 2.;