Cellular Physiology and Biochemistry | |
Caspase 3 is Activated through Caspase 8 instead of Caspase 9 during H2O2-induced Apoptosis in HeLa Cells | |
关键词: Caspase; Hydrogen peroxide; Bax; Apoptosis; | |
DOI : 10.1159/000329955 | |
学科分类:分子生物学,细胞生物学和基因 | |
来源: S Karger AG | |
【 摘 要 】
Oxidative stress is known to be involved in a variety of pathological processes including atherosclerosis, diabetes, and neurodegenerative diseases. Understanding how intracellular signaling pathways respond to oxidative stress will have a significant implication in the therapy of these diseases. In this study, we applied hydrogen peroxide (H2O2) to trigger apoptosis and investigated the dynamic activation of various caspases using a FRET technique. We measured the activation dynamics of caspase 3 and caspase 9 based on two reporter systems, SCAT 3 and SCAT 9. We found that caspase 3 activation was earlier than that of caspase 9 following H2O2 treatment. Caspase 3 was activated rapidly, reaching a maximum in 12±3 min, while the average duration of caspase 9 activation was 21±3 min. When cells were pretreated with Z-LEHD-fmk, a caspase 9 specific inhibitor, caspase 3 activation and apoptosis by H2O2 treatment were little affected, although the caspase 9 activation was completely inhibited. When cells were pretreated with Z-DEVD-fmk, a caspase 3 specific inhibitor, the activation of both caspase 3 and caspase 9, as well as apoptosis, were inhibited. When cells were pretreated with Z-IETD-fmk, a caspase 8 specific inhibitor, the activation of caspase 3 and caspase 9 were significantly delayed. Finally, we found that Bax did not translocate from the cytosol to the mitochondrial membrane during H2O2-induced apoptosis. Our results suggest that, during H H2O2-induced apoptosis, caspase 3 is activated directly through caspase 8 and is not through the mitochondria-dependent caspase 9 activation.
【 授权许可】
CC BY-NC-ND
【 预 览 】
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RO201904033603895ZK.pdf | 400KB | download |