| Autor: |
Fukamachi, Yukiyo, Karasaki, Yuji, Sugiura, Tsutomu, Itoh, Hideaki, Abe, Tetsuya, Yamamura, Kaori, Higashi, Ken |
| Zdroj: |
Biochemical and Biophysical Research Communications; May 1998, Vol. 246 Issue: 2 p364-369, 6p |
| Abstrakt: |
Treatment of human premonocytic U937 cells with 500μM H2O2for 1h followed by 4h incubation in fresh medium to allow the cells to execute apoptotic processes caused DNA fragmentation. However, in the presence of 1mM ZnSO4throughout the incubation, DNA ladder formation was markedly inhibited. Hydrogen peroxide treatment for 1h with or without zinc increased both Bcl-2 and Bax proteins. However, only Bax protein decreased to basal levels in the presence of zinc during the following 4h incubation, resulting in an increase of the Bcl-2/Bax ratio and prevention of apoptosis. Treatment of U937 cells with 1mM ZnSO4alone also decreased the levels of Bax protein. Furthermore, we observed that zinc completely inhibited the activation of CPP32 by H2O2, while no significant changes of ICE activities occurred with either H2O2and/or zinc. These results indicate that the suppression of H2O2-induced apoptosis by zinc is mediated through an increase of the Bcl-2/Bax ratio, which occurs upstream from the activation of CPP32. |
| Databáze: |
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