中文摘要：

目的探讨亚硒酸钠诱导NB4细胞凋亡的过程中,细胞色素c氧化酶亚基Ⅳ(COX Ⅳ)表达的变化情况及其机制和意义。方法用20μmol/L亚硒酸钠作用NB4细胞不同时间,Western blot和RT-PCR分别检测COX Ⅳ蛋白和mRNA表达的变化。活性氧清除剂预处理细胞后Western blot检测COX Ⅳ蛋白表达的变化以及caspase-3的激活。caspase-3抑制剂预处理细胞后Western blot检测COX Ⅳ蛋白表达的变化。瞬时转染干扰NB4细胞中COX Ⅳ表达后,流式细胞术检测细胞凋亡。结果亚硒酸钠诱导NB4细胞COX Ⅳ蛋白表达显著下调,但mRNA表达水平无变化。活性氧清除剂能完全逆转亚硒酸钠引起的COX Ⅳ表达下调与caspase-3激活。caspase-3抑制剂能部分逆转亚硒酸钠引起的COX Ⅳ表达下调。干扰COX Ⅳ表达后,亚硒酸钠诱导的细胞凋亡显著增加。结论在亚硒酸钠诱导NB4细胞凋亡过程中,COX Ⅳ在蛋白水平显著下调。活性氧介导COX Ⅳ下调与caspase-3激活,caspase-3在一定程度上参与COX Ⅳ表达下调,抑制COX Ⅳ能显著提高NB4细胞对亚硒酸钠诱导凋亡的敏感性...

英文摘要：

Objective To explore the mechanism and significance of cytochrome c oxidase subunit Ⅳ(COX Ⅳ) downregulation during apoptosis of NB4 cells induced by sodium selenite.Methods NB4 cells were treated with 20 μmol/L sodium selenite at different time points.COX Ⅳ protein and mRNA were detected by Western blot and RT-PCR,respectively.NB4 cells were pretreated with reactive oxygen species(ROS) scavenger before selenite exposure,and then COX Ⅳ protein expression and caspase-3 activation were detected by Western blot...