Bcl-2蛋白对环匹阿尼酸诱导CHO细胞凋亡的保护作用

Hoechst 33258染色和DNA电泳分析揭示了内质网钙泵抑制剂环匹阿尼酸(CPA)呈浓度依赖性地诱导CHO细胞凋亡, 表现出染色体固缩和DNA片断形成的典型特征. Bcl-2的过度表达对CPA诱导的CHO细胞凋亡具有保护作用. 采用Fura-2技术测定细胞内游离钙浓度(［Ca²⁺］_i)变化，观察到Bcl-2对CPA触发的细胞Ca²⁺库Ca²⁺释放无任何影响. 结果表明Bcl-2蛋白对CPA诱导的CHO细胞凋亡的保护作用不是通过抑制CPA诱导的Ca²⁺释放，而是作用于［Ca²⁺］_i升高的下游途径.

Protection of Bcl-2 protein against cyclopiazonic acid-induced apoptosis in Chinese hamster ovary cells

Cyclopiazonic acid(CPA),an inhibitor of Ca²⁺ pump in endoplasmic reticulum， was capable of inducing apoptosis in Chinese hamster ovary(CHO) cells in a dose- dependent fashion, as Hoechst 33258 staining and DNA gel electrophoresis exhibited a typical apoptotic pattern: chromatin condensation and DNA fragmentation. The overexpression of Bcl- 2 protein in CHO cells resulted in the protection from the CPA- induced apoptosis. Using Fura-2 technique for measurement of ［Ca²⁺］_i transients, no effects of Bcl-2 protein on CPA-triggered Ca²⁺ release from the intracellular Ca²⁺ stores were observed. The results indicate that Bcl-2 protein is capable of protecting CHO cells from CPA- induced apoptosis via interfering with the downstream events of the rise in ［Ca²⁺］_i without inhibition of Ca²⁺ release.