同型半胱氨酸诱导PC12细胞凋亡的研究

Induction of apoptosis in PC12 cells by homocysteine

目的:研究同型半胱氨酸(Hcy)在生理浓度铜离子(10μmol/LCu2+)作用下能否诱导PC12细胞凋亡及对bcl-2、bax基因表达的影响。方法:将细胞随机分成对照组和处理组,采用MTT法检测细胞活力;倒置相差显微镜、荧光显微镜和流式细胞仪检测细胞凋亡;半定量RT-PCR分析bcl-2和baxmRNA的表达水平。结果:0.125-1.0mmol/LHcy在Cu2+的作用下可以导致PC12细胞凋亡,具有明显的剂量-效应关系;bcl-2mRNA表达降低,baxmRNA表达升高,且效应与Hcy浓度相关。结论:高浓度Hcy在生理浓度Cu2+作用下可诱导PC12细胞凋亡,且凋亡作用与Hcy浓度相关。其机制可能是通过调节bcl-2和baxmRNA的比值起作用的。

AIM： To explore the effects of homoeysteine 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 becl-2 and bax mRNA was measured by semiquantitative reverse transcription polymerse chain reaction （RT- PCR）. RESULTS： Treatment of PC12 cells with Hcy plus 10μmol/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.