克霉唑诱导急性早幼粒细胞白血病细胞凋亡与钙离子稳态失调和线粒体膜电位的关系

Relation ship between clotrimazole-induced apoptosis and calcium homeostasis and mitochondrial membrane potential in human acute myeloid leukemias cells

目的:研究钙激活性钾通道阻断剂克霉唑(CLO)诱导人类急性早幼粒细胞白血病(APL)细胞凋亡机制。方法:通过激光扫描共聚焦显微镜实时监测CLO对[Ca2+]i的影响,并观察对内质网钙泵抑制剂Thapsi-gargin的反应,流式细胞仪观察线粒体膜电位,比色法检测caspase-3活性变化。结果:CLO引起[Ca2+]i明显增加,细胞内储存池对Thapsigargin敏感性被克霉唑消除,5μmol/L CLO作用于NB4细胞48h、72h后线粒体膜电位降低,分别是对照组的(1.9±0.1)、(2.1±0.1)倍(P<0.01)。在12h、16h和20h时,caspase-3相对活性与对照组相比分别升高了(1.9±0.2)、(2.7±0.4)、(3.3±0.6)倍。结论:与钙库耗竭有关的胞质内钙离子超载及线粒体膜电位的下降参与钙激活性钾通道阻断剂克霉唑诱导APL凋亡过程。

Objective：To investigate the mechanism of inducing apoptosis by clotrimazole（CLO）,a inhibitor of the intermediate-conductance Ca2＋-activated K＋（IK） channel.Method：The level of intracellular free Ca2＋ was observed with confocal laser scanning microscope.Flow cytometry was used to examine mitochondrial membrane potential.Result：CLO increased the levels of i in NB4. The sensitivity of intracellular stores to thapsigargin had been depleted by clotrimazole.5 μmol/L CLO could reduce the mitochondria membrane potential to 1.9±0.1 and 2.1±0.1 folds of control in 48 h and 72 h.The activity of caspase-3 increased to 1.9±0.2,2.7±0.4,3.3±0.6 folds of control in 12 h,16 h and 20 h.Conclusion：CLO,a inhibitor of IK channel,induced apoptosis of NB4 cells by decreasing intracellular mitochondrial membrane potential and increasing Ca2＋ level.