Involvement of reactive oxygen species and caspase 3 activation in arsenite-induced apoptosis

Yen Chou Chen, S. Y N Lin-Shiau, Jen K. Lin

研究成果: 雜誌貢獻文章同行評審

425 引文 斯高帕斯(Scopus)


Recent studies indicate that arsenic may generate reactive oxygen species to exert its toxicity. However, the mechanism is still unclear. In this study, we demonstrate that arsenite is able to induce apoptosis in a concentration- and time-dependent manner; however, arsenate is unable to do so. An increase of intracellular peroxide levels was accompanied with arsenite-induced apoptosis, as demonstrated by flow cytometry using DCFH-DA. N-Acetyl-L-cysteine (a thiol-containing antioxidant), diphenylene iodonium (an inhibitor of NADPH oxidase), 4,5-dihydro-1,3-benzene disulfonic acid (a selective scavenger of O2/-), and catalase significantly inhibit arsenite- induced apoptosis and intracellular fluorescence intensity. In contrast, allopurinol (an inhibitor of xanthine oxidase), indomethacin (an inhibitor of cyclooxygenase), superoxide dismutase, or PDTC had no effect on arsenite- induced cell death. Activation of CPP32 activity, PARP (a DNA repair enzyme) degradation, and release of cytochrome c from mitochondria to the cytosol are involved in arsenite-induced apoptosis, and Bcl-2 antagonize arsenite- induced apoptosis by a mechanism that interferes in the activity of CPP32. These results lead to a working hypothesis that arsenite-induced apoptosis is triggered by the generation of hydrogen peroxide through activation of flavoprotein-dependent superoxide-producing enzymes (such as NADPH oxidase), and hydrogen peroxide might play a role as a mediator to induce apoptosis through release of cytochrome c to cytosol, activation of CPP32 protease, and PARP degradation.

頁(從 - 到)324-333
期刊Journal of Cellular Physiology
出版狀態已發佈 - 11月 1998

ASJC Scopus subject areas

  • 細胞生物學
  • 臨床生物化學
  • 生理學


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