糖尿病大鼠局灶性脑缺血再灌注海马区Tau蛋白的表达及意义

Expression of Tau Protein of Hippocampal Region in Focal Cerebral Ischemia-reperfusion-injury of Rats with Diabetes and its Significance

目的观察Tau蛋白在糖尿病大鼠脑缺血再灌注海马区神经元的表达,探讨Tau蛋白异常磷酸化神经元毒性作用与神经元损伤的关系。方法健康雄性Wister大鼠60只,随机分为4组:①正常对照组;②假手术组;③脑缺血再灌注组(NIR组);④糖尿病脑缺血再灌注组(DIR组)。采用STZ诱导糖尿病和线栓法建立大脑中动脉闭塞(MCAO)模型,HE法观察海马CA1神经元缺失,用免疫组化方法检测Tau蛋白在糖尿病大鼠脑缺血再灌注海马区神经元的表达。结果HE染色:正常对照与假手术组未见神经元缺失,即未发生神经细胞凋亡;DIR组与NIR组均见神经元缺失,即发生了神经细胞凋亡,而且DIR组发生神经元缺失严重,与NIR组比较有明显差异(P<0.05)。Tau蛋白染色:正常对照与假手术组极少见Tau免疫染色阳性细胞,DIR组与NIR可明显见到Tau免疫染色阳性细胞,而且DIR组Tau免疫染色阳性细胞数比NIR组更多,比较有明显差异(P<0.05)。结论Tau异常磷酸化神经元毒性作用与糖尿病加重脑缺血再灌注海马神经元损伤有关。

Objective To investigate the Tau protein expression and its significance in hippocampal region of cerebral ischemia - reperfusion nerve cells injury of rats with diabetes. Methods 60 healthy male wistar rats were randomly divided into following four groups： the control group, sham operation group, normal ischemia - reperfusion （NIR） group, and diabetic ischemia - reperfusion （DIR） group. The diabetic rats were induced by STZ. The cerebral artery occlusion （MCAO） model was established by thread embolism method. Hematoxylin - eosin （HE） staining was made to observe the number of neuron in hippocampal CAI region. Immunohistochemistrical method was used to detect the Tau protein expression in hippocampal ischemia and reperfusion injuries of diabetic rats. Results In the HE staining, neuronal loss or apoptotic cells weren＇t observed in the control group and sham operation group, but were observed in both NIR and DIR group, and DIR group was more serious than NIR group （P 〈 0. 05）. In the Tau staining, there were very few positive cells expressed Tau in the control group and sham operation group, but were obviously observed in both NIR and DIR group,and the number of positive cells expressed Tau of DIR group was significantly more than that of NIR group （ P 〈 0.05）. Conclusion Neuron toxicity by the Tau protein being abnormal phosphorylated is associated with the hippocampal neuronal injury after cerebral ischemia and reperfusion caused by diabetes.