NGF过表达对大鼠脑缺血再灌注损伤模型认知功能的影响

Effect of NGF overexpression on cognitive function of cerebral ischemia reperfusion injury SD rat

目的探究神经生长因子(nerve growth factor,NGF)过表达对大鼠脑缺血再灌注损伤模型认知功能的影响。方法将SD大鼠分成空白对照组、模型组和NGF转染组。水迷宫实验检测各组大鼠学习能力,荧光定量PCR,Western blot和免疫组织化学染色检测NGF和Caspase-3的相对表达水平,免疫荧光染色定位NGF蛋白的表达,尼氏染色和透射电镜观察神经元细胞的数量以及血脑屏障的完整性。结果 NGF转染组逃避潜伏期时间要明显短于模型组,而穿越平台次数明显多于模型组。NGF转染组NGF蛋白和mRNA相对表达量明显高于模型组,Caspase-3蛋白和mRNA相对表达量明显低于模型组。NGF蛋白与神经元细胞标记蛋白NSE可共染,而与神经胶质细胞标志物GFAP不可共染。NGF转染组细胞数明显多于模型组细胞数。模型组细胞轮廓模糊,血脑屏障破坏,而NGF转染组细胞轮廓存在,血脑屏障破坏较小。结论 NGF的过表达促进神经元细胞的存活,对大鼠脑缺血再灌注损伤模型的认知功能有保护作用。

Objective To investigate the effect of nerve growth factor(NGF) overexpression on cognitive function in SD rats with ischemia-reperfusion injury. Methods SD rats were divided into three groups: blank control group, model group and NGF overexprssion group. The learning ability was determined by Morris water maze, fluorescence quantitative PCR and Western blot and immunohistochemical staining were used to detect the relative expression of NGF and Caspase-3. The expression of NGF protein was localized by immunofluorescence staining. The number, morphology and integrity of blood-brain barrier were observed by Nissl staining and transmission electron microscopy. Results The escape latency was significantly shorter, the number of rats crossing the platform was significantly higher in NGF transfection group than in model group. The relative expression level of NGF protein and mRNA was significantly higher, but lower for Caspase-3, in NGF transfection group than in model group. The number of cells was significantly higher in NGF transfection group than in model group. The cell contour was blurred and the blood-brain barrier was destroyed in model group, but was less destroyed in NGF transfection group. Conclusion Overexpression of NGF promotes the survival of neurons and protects the cognitive function of rats with ischemia-reperfusion injury.