ApoE基因敲除小鼠海马CA3区神经元形态学和微管相关蛋白2表达变化  

Neuronal morphology and microtubule associated protein 2 expression changes in Apo E knockout mice hippocampal CA3 area

作　　者：季丹[1,2] 黄大可[3] 桂丽[3] 贾雪梅[1,2] 

机构地区：[1]安徽医科大学组织学与胚胎学教研室,合肥230032 [2]安徽医学高等专科学校基础部,合肥230061 [3]安徽医科大学综合实验室,合肥230032

出　　处：《安徽医科大学学报》2016年第11期1600-1603,共4页Acta Universitatis Medicinalis Anhui

基　　金：安徽高校省级自然科学研究项目(编号:KJ2012A164)

摘　　要：目的观察载脂蛋白E基因敲除(Apo E KO)对小鼠海马CA3区神经元形态结构改变以及微管相关蛋白2(MAP-2)表达的影响。方法 10只野生型C57BL/6J小鼠为对照组,10只Apo E基因敲除小鼠为KO组,普通饲料喂养3个月。采用分光光度计检测血脂变化;取两组小鼠脑组织,HE染色和电镜技术观察海马CA3区结构改变,免疫组织化学技术观察两组小鼠海马CA3区MAP-2表达变化,采用计算机图像分析系统检测其平均光密度(MOD)值。结果与对照组比较,KO组小鼠血浆总胆固醇、血浆三酰甘油、低密度脂蛋白含量明显升高(P<0.05,P<0.01)。光镜下,KO组小鼠海马CA3区锥体细胞较小,排列稀疏松散。电镜下,KO组海马神经元内线粒体肿胀变性,嵴消失;神经纤维髓鞘松懈;突触小泡数量减少,突触间隙模糊等。免疫组织化学结果显示,对照组小鼠海马神经元内MAP-2高表达,KO组含量明显减少;图像分析显示KO组CA3区MAP-2MOD值明显降低(P<0.05)。结论 Apo E KO小鼠海马神经元结构出现病理改变,MAP-2表达下降,提示Apo E KO与神经退行性病变有一定联系。Objective To observe the effect of apolipoprotein E knockout （ApoE KO） on structural changes in neuronal morphology of hippocampal CA3 area of mice and microtubule-associated protein 2 （MAP-2） expression. Methods 10 normally-fed C57BL/6J wild mice were chosen as the control group, and 10 gene knockout mice were selected as ApoE KO group fed with a common diet for 3 months. Blood lipid changes were detected by spectrophotometer testing. Brain tissues of the two groups of mice were taken out to observe structural changes in hippocampal CA3 area by HE staining and electron microscopy techniques. MAP-2 protein expression changes in hippoeampal CA3 area were observed by immunohistochemical technique. Average optical density （MOD） expression changes were analyzed by computer image system. Results Compared with the control group, plasma total cholesterol, triglyceride and low density lipoprotein cholesterol levels of the KO group were significantly higher （P 〈 0. 05, P 〈0. 01 ）. Light microscope showed that hippoeampal CA3 pyramidal cells of KO group mice were smaller, sparsely and loosely arranged. Under the electron microscope, hippocampal neurons mitochondria of KO group swelled and degenerated and ridge disappeared, myelin sheath of nerve fibers relaxed, the number of synaptic vesicles decreased and synaptie cleft obscured. Immunohistochemical results indicated that the MAP-2 in hippocampal neuron was higher in the control group, whereas that of KO group was remarkably diminishing; image analysis showed that MAP-20D value in CA3 area of KO group significantly decreased （P 〈 0. 05 ）. Conclusion ApoE KO may contribute to pathological changes of hippoeampal neuron structure of mice and decrease MAP-2 expression, which signifies that ApoE KO is correlated with neurodegenerative disorders.

关 键 词：载脂蛋白E基因敲除 微管相关蛋白2 超微结构 海马CA3区 小鼠 

分 类 号：R-332[医药卫生]