缺血后处理通过上调磷酸化丝氨酸/苏氨酸蛋白激酶B阻断细胞色素C释放防护缺血性神经元损伤  

Ischemic postconditioning prevents cytochrome C release through up-regulation of p-Akt and protects neurons against ischemia insult

作　　者：张立柱[1,2] 周彩凤[1,3] 涂静宜[1] 张茜[1] 朱莹[1] 王瑞敏[1] 

机构地区：[1]河北联合大学医学实验研究中心神经生物学研究所,河北唐山063000 [2]唐山市乐亭县医院外科,河北唐山063604 [3]沧州市中心医院科研处,河北沧州061001

出　　处：《解剖学报》2013年第2期152-156,共5页Acta Anatomica Sinica

基　　金：国家自然科学基金资助项目(30970664)

摘　　要：目的通过观察脑缺血再灌注大鼠海马CA1区神经元内丝氨酸/苏氨酸蛋白激酶B(Akt)及细胞色素C的表达及定位情况,探讨延迟性脑缺血后处理神经保护作用及其可能的分子机制。方法制作SPF级成年雄性SD大鼠(40只)四动脉结扎全脑缺血模型。实验动物随机分为假手术组,缺血再灌注组,后处理组,抑制剂组及溶剂对照组。采用焦油紫染色技术观察大鼠海马CA1区神经元存活情况;Western blotting法检测磷酸化Akt及细胞色素C的表达及定位。结果延迟性的脑缺血后处理能够促进缺血再灌注大鼠海马CA1区神经元生存;促进磷酸化Akt水平升高;阻止线粒体内细胞色素C向胞质释放;脑室注射LY294002后,细胞色素C的释放减少,抑制延迟性后处理的神经元保护作用。结论延迟性脑缺血后处理通过诱导胞质内Akt的磷酸化,抑制线粒体内细胞色素C释放到胞质,阻止全脑缺血再灌注后大鼠海马CA1区神经元损伤。Objective The goal of this study is to elucidate the neuro-protective effect and the possible mechanism of delayed ischemic postconditioning through observing the level of p-Akt and cytochrome C （ Cyt C） in cytoplasm or mitochondria following global cerebral ischemia. Methods 40 Adult male Sprague-Dawley rats were subjected to global cerebral ischemia by four-vessel occlusion and were randomly divided into five groups： sham group, ischemia.reperfusion group （I/R）, delayed ischemic postconditioning group （Post C）, Vehicle group （Post C ＋ Vehicle） and LY294002 group （Post C ＋ LY294002）. Cresyl violet staining was used to observe the surviving neurons of hippocampal CA1 region following global cerebral ischemia and western blot analysis was used to detect the level of p-Akt and Cyt C in both cytosolic and mitochondrial fraction. Results Delayed ischemic postconditioning protected the hippocampal CA1 region neurons against ischemia/referfusion injury and significantly increased the level of p-Akt in cytoplasm compared with I/R groups. Delayed ischemic postconditioning markedly prevented the release of Cyt C from mitochondria to cytoplasm and LY294002, an inhibitor of Akt up-stream kinase, abolished the positive role of delayed ischemic postconditioning. Conclusion Delayed ischemic postconditioning induces the Akt activation and prevents the release of Cyt C from mitochondria to cytoplasm, thereby blocks the hippocampal CA1 region neurons injury following global cerebral ischemia.

关 键 词：全脑缺血 延迟性缺血后处理 丝氨酸 苏氨酸蛋白激酶B 细胞色素C 免疫印迹法 大鼠 

分 类 号：R363.2[医药卫生—病理学]