Redox regulation of PI3K/Akt and p53 in bovine aortic endothelial cells exposed to hydrogen peroxide
Redox regulation of PI3K/Akt and p53 in bovine aortic endothelial cells exposed to hydrogen peroxide
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DOI：
10.1089/152308603770380016
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发表时间：
2003-12-01
影响因子：
6.6
通讯作者：
Kuwabara, M
中科院分区：
文献类型：
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作者：
Niwa, K;Inanami, O;Kuwabara, M
为阐明氧化应激激活的血管内皮细胞的凋亡和存活信号转导途径，研究了信号转导抑制剂对过氧化氢(H_2O_2)诱导的牛主动脉内皮细胞(BAEC)凋亡的影响。1 mM H_2O_2处理BAEC后，细胞DNA片段化、P53表达、Bax/Bc l-2比值及caspase3、9活性均增加。细胞内钙离子螯合剂BAPTA-AM和抗氧化剂N-乙酰-L半胱氨酸可抑制BAEC细胞DNA片段化、Bax/Bc l-2比值及caspase活性的增加，而Wortmannin(磷脂酰肌醇3-激酶(PI3K)抑制剂)可增强其作用。在H_2O_2刺激下，细胞内钙离子浓度([Ca~(2+)](I))的升高不受Wortmannin的影响，提示Wortmannin对细胞凋亡的促进作用不是由于细胞内[Ca~(2+)](I)的变化，而是H_2O_2使PI3K活性和Akt磷酸化水平升高。Wortmannin、金雀异黄素(一种酪氨酸激酶抑制剂)和苏拉明(一种生长因子受体抑制剂)都能减弱这两种作用，但不受BAPTA-AM的影响。这些结果提示，H_2O_2诱导细胞内钙离子依赖性的细胞凋亡和非钙离子依赖性的生存信号，如氧化还原调节的PI3K/Akt的激活，这部分是通过激活BAEC中的生长因子受体来实现的。
To clarify the apoptotic and survival signal transduction pathways in activated vascular endothelial cells exposed to oxidative stress, the effects of inhibitors of signal transduction on hydrogen peroxide (H2O2)-induced apoptosis in bovine aortic vascular endothelial cells (BAEC) were examined. Treatment of BAEC with 1 mM H2O2 caused increases of DNA fragmentation, p53 expression, Bax/Bcl-2 ratio, and the activities of caspases 3 and 9. The increases of DNA fragmentation, Bax/Bcl-2 ratio, and caspase activities were abrogated by BAPTA-AM (an intracellular Ca2+ chelator) and N-acetyl-L-cysteine (an antioxidant), and augmented by wortmannin [a phosphatidylinositol 3-kinase (PI3K) inhibitor]. The increase of the intracellular Ca2+ concentration ([Ca2+](i)) observed in H2O2-stimulated cells was unaffected by wortmannin, suggesting that the potentiating effect of wortmannin on the apoptosis was not due to an alteration of [Ca2+](i).H2O2 increased the levels of PI3K activity and Akt phosphorylation. Both were attenuated by wortmannin and, to a lesser extent, by genistein (a tyrosine kinase inhibitor) and suramin (a growth factor receptor inhibitor), but not affected by BAPTA-AM. These results suggest that H2O2 induces Ca2+-dependent apoptosis and Ca2+-independent survival signals such as redox-regulated activation of PI3K/Akt, which is partly mediated by the activation of growth factor receptors in BAEC.