急性脑缺血通过激活EphB2/ephrin-B1/NMDA受体信号通路促进小鼠海马神经发生  

Acute cerebral ischemia activates EphB2/ephrin-B1/NMDA receptor signaling pathway to promote hippocampal neurogenesis in mice

作　　者：马晓娇 承欧梅[2] 校欢 王宸 陈爽[1] 蒋青松[1] 邱红梅[1] MA Xiao-jiao;CHENG Ou-mei;XIAO Huan;WANG Chen;CHEN Shuang;JIANG Qing-song;QIU Hong-mei(Department of Pharmacology,Chongqing Key Laboratory of Biochemistry and Molecular Pharmacology,Chongqing Med-ical University,Chongqing 400016,China;Department of Neurology,The First Affiliated Hospital of Chongqing Medical University,Chongqing 400016,China)

机构地区：[1]重庆医科大学药理学教研室,重庆市生物化学与分子药理学重点实验室,重庆400016 [2]重庆医科大学附属第一医院神经内科,重庆400016

出　　处：《中国病理生理杂志》2020年第8期1389-1395,共7页Chinese Journal of Pathophysiology

基　　金：国家自然科学基金资助项目(No.81871002,No.81471334,No.81100981);重庆市自然科学基金资助项目(No.cstc2017jcyjA0482)。

摘　　要：目的:观察急性脑缺血对小鼠海马神经发生的影响,并探讨该过程是否涉及EphB2/ephrin-B1/NMDA受体信号通路的激活。方法:52只C57BL/6小鼠随机分为2组,即假手术组和急性脑缺血模型组,每组26只,其中每组用于Morris水迷宫实验6只,HE染色4只,BrdU免疫荧光染色4只,双皮质素(DCX)免疫荧光染色4只,RT-qPCR实验4只,Western blot实验4只。采用双侧颈总动脉夹闭法建立小鼠脑缺血模型。HE染色观察小鼠海马CA1区病理改变;Morris水迷宫实验检测小鼠学习与记忆等认知功能的改变;免疫荧光染色观察小鼠海马区BrdU阳性细胞和DCX蛋白表达以评估神经发生情况;RT-qPCR及Western blot检测小鼠海马EphB2、ephrin-B1、reelin、微管相关蛋白2(MAP-2)及NMDA受体亚基NR2A和NR2B的mRNA及蛋白表达。结果:脑缺血小鼠海马CA1区神经元损伤显著(P<0.01),学习记忆功能显著下降(P<0.01),提示脑缺血模型成功建立;海马区BrdU阳性细胞和DCX蛋白表达显著增加(P<0.01),表明脑缺血后海马出现神经发生;同时海马区EphB2、ephrin-B1、reelin、MAP-2、NR2A和NR2B的表达水平也显著上调(P<0.05)。结论:急性脑缺血能促进小鼠海马神经干细胞增殖及内源性神经发生,其促进神经发生的机制可能与激活EphB2/ephrin-B1/NMDA受体信号通路有关。AIM:To investigate the effect of acute cerebral ischemia on hippocampal neurogenesis in mice and its possible mechanism involving EphB2/ephrin-B1/NMDA receptor signaling pathway.METHODS:C57BL/6 mice(n=52)were randomly divided into sham group and acute cerebral ischemia group(model group). The model of acute cerebral ischemia in mice was established by bilateral common carotid artery occlusion. The pathological changes of the hippocampal CA1 region in mice were observed by HE staining. The learning and memory functions of the mice were assessed by Morris water maze. The BrdU positive cells and doublecortin(DCX)protein expression were observed by immunofluorescence staining for detecting hippocampal neurogenesis. The mRNA and protein expression levels of EphB2,ephrinB1,reelin,microtubule-associated protein-2(MAP-2)and NMDA receptor subunits NR2A and NR2B in the hippocampus were determined by RT-qPCR and Western blot.RESULTS:The neuronal damage in the hippocampal CA1 region was significant(P<0. 01),and the learning and memory functions were significantly decreased in the cerebral ischemia mice(P<0. 01),suggesting that the cerebral ischemia model was successfully established. The BrdU positive cells and DCX protein expression were increased significantly(P<0. 01),indicating that neurogenesis occurred in the hippocampus after cerebral ischemia. At the same time,the mRNA and protein expression levels of EphB2,ephrin-B1,reelin,MAP-2,NR2A and NR2B in the hippocampus were also significantly up-regulated(P<0. 05).CONCLUSION:Acute cerebral ischemia promotes the proliferation of hippocampal neural stem cells and endogenous neurogenesis,which may be related to the activation of EphB2/ephrin-B1/NMDA receptor signaling pathway.

关 键 词：急性脑缺血 海马 神经发生 EphB2/ephrin-B1/NMDA受体信号通路 

分 类 号：R743.3[医药卫生—神经病学与精神病学] R363.2[医药卫生—临床医学]