局灶性脑缺血后神经干细胞增殖及GDNF表达变化的实验研究

摘要

Objective To investigate the neural stem cells (NSCs ) proliferation and itsrelalion with glialcellline-de-rived neurotrophic factor(CDNF)expression after focal cerebral ischemia. Methods Total of 24 SD rats were divided into sham group and model 1 group, model 2 group, model 3 group, with 6 in each, the Later three groups were made focal cerebral ischemia model by middle cerebral artery occlusion ( MCAO) , then were executeded 3, 7 and 14 days after operation ; the sham group was treated as the above groups, but middle cerebral artery was not blocked . The protein expression of BrdU, Neslin and GDNF were detected by immunohistochemical method, the NSCb was identified by Brdll/Nestin immun-oflurenaent double label. Results Compared with the sham group, the BrdU positive cells were significantly increased in the injuried lateral subventricular zone (SVZ) of model 1 and 2 groups (both P <0.05), which in the model 3 group was similar; the BrdU positive cells of the cortex around the infarction focus in the model 2 and 3 groups were increased significantly ( P < 0. 01 or 0.05); the Nestin positive cells in the injuried lateral cortex of the model 1 and 2 groups were increased 9ignificantly( both P <0.01), immunofluresent double label showed that the BrdU positive cells almost were Nestin positive; the GDNF positive cells were significantly increased in the injuried lateral (both P <0. 05). Conclusion The proliferation of endogenous NSCs accelerates 3-14 ds after focal cerebral Ischemia, which may be promoted by increase of GDNF expression.%目的 研究局灶性脑缺血后大鼠脑内神经干细胞(NSCs)增殖情况及与胶质细胞源性神经营养因子(GDNF)表达变化的关系.方法 将24只SD大鼠随机分为假手术组和模型1组、模型2组、模型3组各6只,后三组用大脑中动脉栓塞法(MCAO)制备局灶性脑缺血模型,分别于术后3、7、14 d处死；假手术组除不以尼龙线阻塞大脑中动脉起始部外,其他操作与模型1组相同.采用免疫组化染色法观察5-溴脱氧尿嘧啶核苷(BrdU)标记的细胞及巢蛋白(Nestin)、GDNF阳性细胞表达,BrdU/Nestin免疫荧光双标法观察NSCs变化.结果 模型2组损伤侧脑室下层(SVZ) BrdU阳性细胞显著多于假手术组(P＜0.05),模型3组与假手术组相似；模型2、3组皮层梗死灶周围BrdU阳性细胞均显著多于假手术组(P＜0.01、0.05)；模型1、2组皮层梗死灶周围Nestin阳性细胞均显著多于假手术组(P均＜0.01),BrdU/Nestin免疫荧光双标显示BrdU阳性细胞几乎均为Nestin阳性；模型2、3组皮层梗死灶周围GDNF阳性细胞均显著多于假手术组(P均＜0.05).结论 大鼠局灶性脑缺血后3～14 d内源性NSCs增殖加快,GDNF表达增加可能对其起促进作用.