Induction of apoptosis in PC12 cells by homocysteine

AIM: To explore the effects of homocysteine on the apoptosis in PC12 cells and the relationship between the apoptosis and the expression of the bcl-2 as well as bax gene. METHODS: Cell viability was determined by MTT assay. Cell apoptosis was assessed by phase-contrast microscope, fluorescence microscopy and flow cytometry (FCM). The expression of bcl-2 and bax mRNA was measured by semiquantitative reverse transcription polymerse chain reaction (RT-PCR). RESULTS: Treatment of PC12 cells with Hcy plus 10 μmol/L copper for 12 h, in the range of 0.125, 0.25, 0.5, 1.0 mmol/L, caused a great decrease in cell viability: 81%, 79%, 69%, 57%, and induced typical morphological changes of apoptosis in a dose-dependent manner. The apoptosis ratios were respectively 8.00%, 10.37%, 17.26% and 20.19%, respectively. The expression of bcl-2 was significantly decreased (from 0.517 to 0.198) whereas bax was significantly increased (from 0.302 to 0.619). CONCLUSION: Homocysteine plus copper may induce apoptosis in PC12 cells through the down-regulation of bcl-2 and the up-regulation of bax gene expression.