PI3K p55γ promoter activity enhancement is involved in the anti-apoptotic effect of berberine against cerebral ischemia-reperfusion
PI3K p55γ promoter activity enhancement is involved in the anti-apoptotic effect of berberine against cerebral ischemia-reperfusion
复制标题
DOI：
10.1016/j.ejphar.2011.11.014
复制
发表时间：
2012-01-15
影响因子：
5
通讯作者：
Du, Lijun
中科院分区：
文献类型：
--
作者：
Hu, Jun;Chai, Yushuang;Du, Lijun
黄连素是治疗缺血性卒中的候选临床神经保护剂。在本研究中，我们研究了PI3K/Akt通路在小檗碱抗细胞凋亡作用中的影响。采用缺氧缺糖、神经生长因子诱导的PC12细胞和原代神经元复氧、小鼠双侧颈总动脉阻断作为体内外缺血模型。我们发现，黄连素的抗缺血作用确实是通过增加Akt(p-Akt与总Akt之比)的磷酸化，导致Bad的磷酸化增强，使促凋亡的蛋白酶caspase-3的裂解减少而实现的。黄连素的作用是PI3K所特有的，而不是上游受体酪氨酸激酶。酪氨酸激酶抑制剂金雀异黄素和表皮生长因子受体抑制剂PD153035可维持其抗凋亡作用，而PI3K抑制剂Ly294002和Akt抑制剂Akti-1/2则可抑制其作用。在缺血再灌流过程中，黄连素可上调PI3K调节亚基P55γ，但不被这些抑制剂阻断。我们构建了报告质粒来检测PI3K P55γ启动子的活性，发现黄连素在脑缺血再灌流过程中增强了PI3K P55伽马启动子的活性。(C)2011爱思唯尔B.V.保留所有权利。
Berberine is a candidate clinical neuroprotective agent against ischemic stroke. In the present study, we examined the influence of the PI3K/Akt pathway in mediating the anti-apoptotic effects of berberine. Oxygen-glucose deprivation and reoxygenation of nerve growth factor-differentiated PC12 cells and primary neurons, and bilateral common carotid artery occlusion in mice were used as in vitro and in vivo ischemia models. We found that the anti-apoptotic effects of berberine against ischemia were indeed mediated by the increased phosphor-activation of Akt (higher p-Akt to total Akt), leading to the intensified phosphorylation of Bad and the decreased cleavage of the pro-apoptotic protease caspase-3. Berberine action is specific for PI3K, rather than the upstream receptor tyrosine kinase. The anti-apoptotic effect is maintained in the presence of tyrosine kinase inhibitor genistein and the epidermal growth factor receptor inhibitor PD153035, but is suppressed by the PI3K inhibitor Ly294002 and the Akt inhibitor Akti-1/2. The unique PI3K regulatory subunit p55 gamma was upregulated by berberine during ischemia-reperfusion and was not blocked by these inhibitors. We constructed a reporter plasmid to detect PI3K p55 gamma promoter activity and found that berberine enhanced PI3K p55 gamma promoter activity during cerebral ischemia-reperfusion. (C) 2011 Elsevier B.V. All rights reserved.