The effect of TNF-α on induction of apotosis and the expression of genes bax and bcl-xl in PC12 cells

Objective To investigate the apoptosis induced by tumor necrosis factor α(TNF-α) and the effect of TNF-α on expression of genes bax and bcl-xl in cultured PC12 cells.Methods Using PC12 cells as the model of dopaminergic neurons,cell survival rate was deternined with MTT assay.PI and Annexin V co-fluorescent staining was performed,then PC12 cells apoptosis were detected by flow cytometry and electron microscope.The expressions of bax and bcl-xl mRNA and the proteins were evaluated with RT-PCR and Western blot respectively.Results TNF-α(1~100ng/ml) dose-dependently inhibited PC12 cells prolifenration,morphological evidence of nuclear condensation for apotosis and PI co-fluorescent staining were observed in PC12 cells after treatment of TNF-α(30ng/ml).RT-PCR and Western blot showed that downregulation of bcl-xl mRNA and protein levels appeared,but the expression levels of bax mRNA and protein increased after treatment of TNF-α.Conclusion The expression changes of bcl-xl and bax genes might be related to the apoptosis caused by TNF-αin PC12 cells.