Dual regulation of caspase activity by hydrogen peroxide: implications for apoptosis

FEBS Letters

Hampton, Mark B¹  Orrenius, Sten¹ 

[1] Institute of Environmental Medicine, Division of Toxicology, Karolinska Institutet, Box 210, S-171 77 Stockholm, Sweden

关键词: Apoptosis;    Necrosis;    Reactive oxygen species;    Hydrogen peroxide;    Caspase;    ROS;    reactive oxygen species;    AMC;    aminomethylcoumarin;    PS;    phosphatidylserine;   

DOI  :  10.1016/S0014-5793(97)01068-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The induction of apoptosis in Jurkat T-lymphocytes with 50 μM hydrogen peroxide was associated with caspase activation. Caspase activity was first detected 3 h after treatment, and the morphological features of apoptosis were apparent by 6 h. At higher concentrations of hydrogen peroxide there was no detectable caspase activity, and the cells died by necrosis. Cells treated with hydrogen peroxide were impaired in their ability to undergo Fas-mediated apoptosis. This appeared to be the result of direct inhibition of the cysteine-dependent caspases. The cells were able to recover and undergo apoptosis at later times. Therefore, hydrogen peroxide has two distinct effects. It initially inhibits the caspases and delays apoptosis. Then, depending on the degree of the initial oxidative stress, the caspases are activated and the cells die by apoptosis, or they remain inactive and necrosis occurs. We discuss the physiological implications of cells having to maintain a reducing environment during apoptosis to allow the caspases to function.

【 授权许可】

Unknown