新生大鼠神经干细胞移植对脑缺血再灌注损伤的治疗作用

Therapeutic effects of neural stem cells transplantation on focal cerebral ischemic-reperfusion injury in newborn rat

目的：探讨新生大鼠神经干细胞移植治疗局灶性脑缺血再灌注损伤的可行性及疗效。方法：体外培养新生大鼠神经干细胞。采用改良的线栓法制作脑缺血再灌注模型，3d后用脑立体定位仪经脑室移植神经干细胞，移植时间点及再灌注1～7周对移植大鼠进行神经功能损伤程度评分（NSS）。再灌注1、2、3、5、7周末麻醉处死大鼠，脑组织石蜡包埋。免疫组织化学方法观察移植后神经干细胞的存活、分布。结果：神经干细胞表达巢蛋白，在血清条件下分化为表达微管相关蛋白（MAP2）的神经元和表达胶质细胞纤维酸性蛋白（GFAP）的星形胶质细胞。神经干细胞移植组NSS评分在各个时间点均显著低于对照组。移植的神经干细胞分布于缺血侧皮质、纹状体，再灌注后3、5、7周，皮质、纹状体阳性细胞数分别较1、2周显著增多，第3、5、7周之间差异无统计学意义。前3周组织结构疏松，缺损严重，而第5、7周组织结构较前3周完整致密。结论：移植的神经干细胞能在脑缺血大鼠脑内存活、迁移，并能改善缺血后大鼠的神经功能状况。

Objective： To explore the feasibility and therapeutic effect of transplantation of the neural stem cells （NSCs） from neonatal rat on focal cerebral ischemic-reperfusion injury. Methods： The isehemic-reperfusion injured rats were duplicated by means of middle cerebral artery occlusion （MCAO） and intransplantated with cultured NSCs derived from neonatal rats into the lateral cerebral ventricle 3 days after reperfusion using sterotaxis instrument. All rats underwent Neurological Severity Score （NSS） tests at 3 day after implantation and 1, 2, 3, 5 and 7 weeks after reperfusion, and the survival and distribution of NSE in vivo was subsequently checked at the same time after reperfusion. Results. The NSCs from neonatal rats expressed nestin and differentiated into neurons expressing MAP2 and astrocytes expressing GFAP in presence with serum. NSS in NSCs transplantation group was significantly lower compared with that in the control group throughout the experimental course. The transplanted NSCs were localized on the cortex and striatum in the lesion side, and increased significantly since the 3rd week after reperfusion and last to the 7th week. The structures of the nerve tissue changed to relative integrity from the 5th week after reperfusion. Conclusion： The transplanted NSCs can survive and migrate and effectively improve neurological function of rats with cerebral ischemia.