辛伐他汀诱导K562细胞凋亡过程中对线粒体膜电位的影响

目的:观察辛伐他汀诱导人红白血病K562细胞凋亡时线粒体膜电位(Δψm)的变化及其与时间的关系。方法:常规培养细胞24h,辛伐他汀(20μmol.L-1)处理K562细胞12、24、48、72h,观测细胞形态学改变;MTT法检测细胞增殖抑制情况;流式细胞术检测细胞凋亡率和线粒体膜电位改变,并与溶剂对照组比较。结果:与对照组比较,辛伐他汀作用K562细胞48h后细胞出现核固缩、核碎裂和凋亡小体等形态学改变;作用12、24、48、72h后细胞凋亡率分别增加(2.55±0.35)%、(6.1±0.35)%、(14.15±0.42)%、(30.70±0.65)%,K562细胞凋亡率随着药物作用时间延长而增加;细胞膜电位降低百分率分别为(0.7±0.24)%、(39.6±4.80)%、(24.4±2.45)%、(6.0±1.62)%,24h时膜电位降低百分率最大。结论:线粒体跨膜电位降低是凋亡发生的早期事件,辛伐他汀诱导K562细胞凋亡的可能机制是通过使线粒体跨膜电位崩溃,从而导致细胞凋亡。

Changes in Mitochondrial Membrane Potential of K562 Cells in the Process of Apoptosis Induced by Simvastatin

OBJECTIVE:To observe the changes of mitochondrial membrane potential(MMP)at different time in the process of simvastatin-induced apoptosis of K562 cells.METHODS:K562 cells cultivated by routine method for 24h were treated in the 20μ mol· L-1 simvastatin for 12,24,48,and 72h,respectively.And theh cell morphological changes were observed.Vitality of K562 cells was detected with MTT;flow cytometry were performed to detect cell apoptotic ratio and changes of mitochondrial membrane potential,and the detection results were compared with those in solvent control group.RESULTS:As compared with control group,the morphology changes of K562 cells such as karyopyconosis,nuclear fragmentation and apoptotic body emerged after treatment with 20μ mol· L-1 simvastatin for 48h;the apoptotic ratio at 12,24,48,and 72h increased by(2.55± 0.35)%,(6.1± 0.35)%,(14.15± 0.42)%,and(30.70± 0.65)%,respectively;and the apoptotic ratio of K562 cells increased time-dependently.The cell membrane potential was decreased by(0.7± 0.24)%,(39.6± 4.80)%,(24.4± 2.45)%,and(6.0± 1.62)%,respectively,with that at 24h showing the highest decreasing rate.CONCLUSION:The change of MMP is the early events of apoptosis.The potential mechanism of K562 cells apoptosis induced by simvastatin might be related to the collapse of MMP.