科研之友
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摘要
Accumulating evidence suggests that AMP-activated protein kinase (AMPK) activation exerts anti-apoptotic effects in multiple types of cells. However, the underlying mechanisms remain poorly defined. The aim of the present study was to determine how AMPK suppresses apoptosis in endothelial cells exposed to hypoxia and glucose deprivation (OGD). AMPK activity, NF-kappa B activation, and endothelial cell apoptosis were assayed in cultured endothelial cells and mouse common carotid artery with or without OGD treatment. OGD markedly activated AMPK as early as 30 min, and AMPK activity reached maximal at 2 h of OGD. Endothelial apoptosis was not detected until 2 h of OGD but became markedly elevated at 6 h of OGD treatment. Furthermore, AMPK inhibition by Compound C or overexpression of dominant negative AMPK(AMPK-DN) exacerbated, whereas AMPK activation by pharmacologic (aminoimidazole carboxamide ribonucleotide (AICAR)) or genetic means (overexpression of constitutively active AMPK) suppressed endothelial cell apoptosis caused by OGD. Concomitantly, AMPK activation increased the expression of both Bcl-2 and Survivin, two potent anti-apoptotic proteins. Furthermore, AMPK activation significantly enhanced I kappa B alpha kinase activation, NF-kappa B nuclear translocation, and DNA binding activity of NF-kappa B. Consistently, selective inhibition of NF-kappa B, which abolished OGD-enhanced expression of Bcl-2 and Survivin, accentuated endothelial apoptosis caused by OGD. Finally, we found that genetic deletion of the AMPK alpha 1, but not AMPK alpha 2, suppressed OGD-enhanced NF-kappa B activation, the expression of Bcl-2 and Survivin, and endothelial apoptosis. Overall, our results suggest that AMPK alpha 1, but not AMPK alpha 2 activation, promotes cell survival by increasing NF-kappa B-mediated expression of anti-apoptotic proteins (Bcl-2 and Survivin) and intracellular ATP contents.
- 出版日期2010-5-14
- 单位湖北科技学院
