小鼠脑皮质p-Akt、p53在缺血再灌后处理脑保护机制中的作用  

Effect of ischemic post-conditioning on expression of p-Akt and p53 after cerebral ischemic/reperfusion in mice cortex

作　　者：冉芳[1] 崔颖[2] 高俊玲[1] 田艳霞[1] 李冉[1] 刘媛媛[1] 崔建忠[3] 

机构地区：[1]华北煤炭医学院基础医学部,河北省煤矿卫生与安全实验室,河北唐山063000 [2]河北医科大学临床医学系,石家庄050017 [3]唐山市工人医院神经外科,河北唐山063000

出　　处：《解剖学报》2011年第3期328-333,共6页Acta Anatomica Sinica

基　　金：河北省自然科学基金资助项目(C2009001247);河北省教育厅重点课题资助项目(ZH200803)

摘　　要：目的观察p-Akt、p53在小鼠局灶性脑缺血再灌注(I/R)及缺血后处理(IPO)后在脑皮质区的表达规律,探讨p-Akt、p53与IPO保护作用的关系。方法采用线栓法制备大脑中动脉栓塞的局灶性脑缺血模型,将272只小鼠随机分为假手术(Sham)组、缺血再灌(I/R)组、PI-3K/Akt抑制剂LY294002(LY)组和缺血后处理(IPO)组。I/R组、LY组与IPO组均实施缺血90min之后再灌注,IPO组在持续再灌前采取再灌15s、缺血15s、再灌15s的循环,共3个循环。于再灌后30min、1h、3h、6h、24h、48h分别取材,2,3,5-氯化三苯基四氮唑(TTC)染色法测定脑梗死体积;免疫组织化学法观察p-Akt,p53蛋白的表达及分布;免疫印迹法检测皮质区p-Akt和p53蛋白表达量。结果 Sham组、I/R组和IPO组的非缺血脑半球皮质p-Akt有微量表达。与Sham组相比,I/R组再灌后30min缺血区皮质p-Akt增加,1h达高峰,6h逐渐降低,24h降至Sham组水平并持续;p53再灌后6h增加,24h达高峰,48h回落。各相应时间点IPO组较I/R组p-Akt增高(P<0.05),p53降低(P<0.05)。LY组p-Akt低于I/R组(P<0.05),p53高于I/R组(P<0.05)。顶叶脑组织的免疫印迹分析结果与免疫组织化学结果规律一致。结论缺血后处理对缺血再灌注性脑损伤有保护作用,其机制与降低p53表达及增强p-Akt表达有关。Objective To investigate the role of apoptotic proteins p-Akt and p53 in cortex after brain ischemia/ reperfusion in mice, and the relationship between p-Akt, p53 and brain ischemie post-conditioning. Methods The models of focal cerebral ischemic post-conditioning were made by middle cerebral artery occlusion （MCAO） using an intraluminal filament method. Two hundred and seventy-two male mice were randomly divided into 4 groups： Sham group, isehemic/ reperfusion （I/R） group, LY294002 （ LY, inhibitor of PI-3K） group, isehemic post-conditioning （IPO） group. Sham group received sham surgery only, I/R group received 90 minutes of MCAO, and IPO group received the three cycles of 15 seconds of reperfusion and 15 seconds of middle cerebral artery occlusion after 90 minutes of MCAO. After all groups were subjected the right time reperfusion, the expression of p-Akt and p53 were measured with immunohistochemistry and Western blotting in each group. It was estimated the volume ratio of the cerebral infarction by triphenyhetrazolium chloride （TTC） staining. Results Compared with sham group, p-Akt began to increase at half an hour after reperfusion, peaked at the 1st hour, decreased from the 6th hour, at the 24th hour returned to base level in the isehemie cortex in I/R group. p53 increased from the 6th hour after reperfusion and peaked at the 24th hour and then reduced at the 48th hour in the ischemic cortex in I/R group. At the corresponding time, compared with I/R group, the expression of p-Akt increasedremarkably in IPO group （ P 〈 0. 05 ） ; meanwhile, the expression of p53 decreased significantly in IPO group （ P 〈 0.05 ）. While the expression of p-Akt remarkably reduced, p53 rised sharply in LY group. Conclusion IPO has protecting effect after isehemic/reperfusion, one of mechanisms is up-regulating the activation of p-Akt and down-regulating the activation of p53.

关 键 词：缺血再灌注 缺血后处理 P-AKT P53 免疫组织化学 免疫印迹法 小鼠 

分 类 号：R743.3[医药卫生—神经病学与精神病学]