中文摘要：

目的观察骨髓间充质干细胞移植（mesenchymal stem cells,MSCs）对慢性脑缺血大鼠认知功能及海马CA1区EphB2的影响。方法将SD大鼠随机分为假手术组、模型组、实验组（2VO模型＋MSCs干预）,选8、10、12w 3个时间点,采用双侧颈总动脉永久性阻断法（2VO）建立慢性脑缺血模型,通过Morris水迷宫检测各组大鼠的认知功能,同时用免疫组织化学的方法和Western blot检测大鼠海马CA1区EphB2的表达。结果模型组和实验组大鼠与假手术组相比逃避潜伏期明显延长,在同一时间点实验组逃避潜伏期较模型组明显缩短（P〈0.05）,实验组海马CA1区EphB2的表达较模型组增多（P〈0.05）。结论骨髓间充质干细胞移植能明显改善大鼠慢性脑缺血所致的认知功能障碍,其机制可能是通过升高EphB2的表达而改善学习记忆能力。

英文摘要：

Objective To investigate the effect of mesenchymal stem cells transplantation on cognitive impairment and the expression of EphB2 in Hippocampus CA1 pyramidal cells of the chronic cerebral ischemic rats. Methods Rats were randomly divided into sham operation group, model group （permanent ligation of bilateral common carotid arteries, 2VO） and MSCs group. Each group was subdivided into 8,10 and 12 weeks groups, Cognitive function was evaluated by the Morris water maze and the expression of EphB2 protein was measured using by Western blotting and immunohistochemistry. Results In the Morris water maze test, the escape latency of the rats in model group and MSCs group obviously extended compared to that in the sham operation group（P 〈 0.05） ,while the escape latency in the MSCs group was shorter than that of model group（P 〈0.05） , the expression of EphB2 in hippoeampal CA1 areas in the MSCs group significantly increased than that of the model group by immunohistochemistry and Western blot test （ P 〈 0.05 ）. Conclusion MSCs transplanta- tion could improve cognitive function of chronic cerebral ischemia rats,the improvement maybe due to the increased expres- sion of EphB2.