Wang Haitao, Yang Xiangliang, Zhang Zhihong, Xu Huibi
College of Pharmacy, Wuhan University, Wuhan 430072, China.
J Inorg Biochem. 2003 Oct 1;97(2):221-30. doi: 10.1016/s0162-0134(03)00284-8.
Recent studies have shown that reactive oxygen species (ROS) play a crucial role in Se-induced cell apoptosis. A number of studies have demonstrated that perturbed cellular calcium homeostasis has been implicated in apoptosis. The main objective of this study was to evaluate the role of Ca(2+) in Na(2)SeO(3)-induced apoptosis and the relationship between Ca(2+) and ROS in human colonic carcinoma cells SW480. When SW480 cells were exposed to 25-100 microM Na(2)SeO(3), both cell apoptosis and growth inhibition were observed by flow cytometric analysis and 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. Na(2)SeO(3) was able to induce increase of Ca(2+) and ROS production and disrupt mitochondrial membrane potential (Delta Psi m) in SW480 cells monitored by using a confocal laser scanning microscope. Ca(2+) channel inhibitor CoCl(2) and an intracellular Ca(2+) chelator o-phtalaldehyde, 1,2-bis(2-aminophenoxy)-ethane-N,N,N',N'-tetra-acetic acid acetoxymethyl ester (BAPTA) completely inhibited Ca(2+) increase, but catalase had no effect on Na(2)SeO(3)-induced increase of Ca(2+). BAPTA-AM, CoCl(2), and mitochondrial Ca(2+) uptake inhibitor ruthenium red blocked Delta Psi m dissipation. The increase of ROS was also suppressed by CoCl(2), BAPTA, ruthenium red, N-acetylcysteine and catalase, respectively. The mitochondrial uncoupler carbonyl cyanide p-(trifluoromethoxy) phenylhydrazone (FCCP) completely inhibited Na(2)SeO(3)-induced ROS increase. This showed that ROS increase is due to mitochondrial Ca(2+) overload. The Na(2)SeO(3)-induced apoptosis of SW480 cells was also inhibited by CoCl(2), BAPTA, ruthenium red, N-acetylcysteine, and catalase, respectively. The results mentioned above imply that both calcium and Ca(2+)-dependent ROS as a signal molecule mediate apoptosis induced by Na(2)SeO(3) in SW480 cells.
最近的研究表明，活性氧（ROS）在硒诱导的细胞凋亡中起关键作用。许多研究已证明，细胞钙稳态紊乱与细胞凋亡有关。本研究的主要目的是评估Ca(2+)在亚硒酸钠（Na(2)SeO(3)）诱导的人结肠癌细胞SW480凋亡中的作用以及Ca(2+)与ROS之间的关系。当SW480细胞暴露于25 - 100 microM的Na(2)SeO(3)时，通过流式细胞术分析和3 - [4,5 - 二甲基噻唑 - 2 - 基] - 2,5 - 二苯基四氮唑溴盐（MTT）法观察到细胞凋亡和生长抑制。使用共聚焦激光扫描显微镜监测发现，Na(2)SeO(3)能够诱导SW480细胞内[Ca(2+)]i升高、ROS产生增加并破坏线粒体膜电位（ΔΨm）。Ca(2+)通道抑制剂CoCl(2)和细胞内Ca(2+)螯合剂邻苯二甲醛、1,2 - 双（2 - 氨基苯氧基）乙烷 - N,N,N',N' - 四乙酸乙酰甲酯（BAPTA）完全抑制了[Ca(2+)]i的升高，但过氧化氢酶对Na(2)SeO(3)诱导的[Ca(2+)]i升高没有影响。BAPTA - AM、CoCl(2)和线粒体Ca(2+)摄取抑制剂钌红可阻止ΔΨm的消散。CoCl(2)、BAPTA、钌红、N - 乙酰半胱氨酸和过氧化氢酶也分别抑制了ROS的增加。线粒体解偶联剂羰基氰化物对 - （三氟甲氧基）苯腙（FCCP）完全抑制了Na(2)SeO(3)诱导的ROS增加。这表明ROS增加是由于线粒体Ca(2+)过载。CoCl(2)、BAPTA、钌红、N - 乙酰半胱氨酸和过氧化氢酶也分别抑制了Na(2)SeO(3)诱导的SW480细胞凋亡。上述结果表明，钙和Ca(2+)依赖性ROS作为信号分子介导了Na(2)SeO(3)诱导的SW480细胞凋亡。
