小鼠脑缺血/再灌注对小胶质细胞形态及功能的影响

目的观察小鼠脑缺血/再灌注后小胶质细胞的形态及其表达的促炎因子及酶类变化,探讨小胶质细胞在小鼠脑缺血/再灌注损伤后炎症反应中的作用。方法 48只清洁级雄性昆明小鼠,采用随机方法分为假手术组和模型组,每组24只,再随机将每组分为3个小组,每组8只。制备小鼠右侧大脑中动脉闭塞1h再灌注24h模型,采用Zea Longa评分法行神经功能缺损评分,用2,3,5-三苯基氯化四氮唑(TTC)染色观察缺血后脑梗死体积;采用免疫组化技术观察脑组织中小胶质细胞形态、数量以及iNOS的表达。用酶联免疫吸附法检测脑组织TNF-α的含量。结果小鼠脑缺血1h再灌注24h可引起脑梗死和神经功能缺损。免疫组化显示假手术组小鼠皮层区小胶质细胞呈分支状,胞体小,阳性细胞数(5.97±1.27)个/HP,模型组小鼠皮层区小胶质细胞分支增多,胞体肥大,阳性细胞数(11.36±1.80)个/HP,两组比较差异有统计学意义(P<0.05)。模型组小鼠皮层区iNOS表达及TNF-α含量高于假手术组,差异有统计学意义(P<0.05)。结论小鼠脑缺血/再灌注可引起小胶质细胞激活,发生形态改变,引起脑内iNOS蛋白表达增加及TNF-α释放增多,从而加重脑缺血/再灌注后神经损伤作用。

The influence form and function of microglia in mouse models of ischemia and reperfusion

Objective To investigate the changes of proinflammatory cytokine and enzymeo of microglia,explore the role of microglia in the ischemia-reperfusion inflammatory injury.Methods Forty eight clean level Kunming mice were randomly divided into two groups:sham group(n=24) and model group(n=24).And then randomly divided into three subgroups of sham group and model group,each group had 8 mice.A mice model was made by right side of the brain artery occlusion 1 h and reperfusion 24 h model.Zea Longa grading line was used for neural function defect scale,the infarct size was determined by 2,3,5-triphenyiterazoloride(TTC) staining.The morphological change of microglia,the numbers of microglia and iNOS were observed with immunohistochemistry.The enzyme-linked immunosorbent assay(ELlSA) was used to detect the concentration of TNF-α in brain tissue.Results Ischemia 1 h reperfusion 24 h can cause the stable infarction volume and neurological deficit score on the cortex.The cortex of sham-operation group displayed the microglia branches,the small of cyton,and the positive expression cells were(5.97±1.27) ind /HP.The cortex of model group displayed hyperplasia of microglia,the large of the cyton,and the positive expression cells were(11.36±1.80) ind /HP.There were significant differences compared to the sham-operation group(P<0.05).The levels of iNOS and TNF-α in model group were higher than sham group,there was significant difference(P<0.05).Conclusion The cerebral ischemia/reperfusion model can induce microglia activation in the cortex of mouse,cause the increase of the expression of the iNOS protein and release of the TNF-α.Thus aggravating cerebral ischemia reperfusion nerve injury.