神经干细胞移植对阿尔茨海默病大鼠海马神经分化和功能的影响

Effect of neural stem cells transplantation on differentiation and function of Alzheimer's disease rat hippocampus

目的:观察海马神经干细胞(NSCs)移植入AD大鼠海马后的存活、分化及功能状态。方法:SD大鼠40只,随机分为正常对照组,AD模型组,2、4、6周移植组,每组8只。从新生大鼠海马齿状回分离、培养NSCs,并用Hoechst33258标记。各移植组制备AD模型7d后,将NSCs植入海马。正常对照组和AD模型组于移植后2周,各移植组于移植后2、4和6周,行Y迷宫实验检测大鼠的学习获得能力和记忆再现能力,取海马行神经微丝蛋白200(NF-200)、胶质纤维酸性蛋白(GFAP)荧光免疫组织化学染色和突触素免疫组织化学染色。结果:2周移植组Ho-echst33258标记细胞不表达NF-200、GFAP,4、6周移植组NF-200、GFAP阳性率约为1%和10%。5组海马CA1区突触素表达差异有统计学意义(F=47.52,P<0.05);AD模型组大鼠海马内突触素平均光密度值为(0.18±0.01),低于正常对照组的(0.27±0.01)(P<0.05),2、4和6周移植组大鼠海马内突触素平均光密度值分别为(0.38±0.01)、(0.37±0.01)和(0.37±0.01),均明显高于对照组和AD模型组(P均<0.05)。行为学测试结果显示,5组大鼠学习获得能力和记忆再现能力差异有统计学意义(F=63.52,24.36,P均<0.05),AD模型组大鼠学习、记忆能力下降,2、4和6周移植组大鼠学习、记忆能力明显得到恢复(P均<0.05)。结论:移植入脑内的NSCs可分化为神经元和神经胶质细胞,促进突触重建,改善学习记忆能力。

Aim ： To observe the survival and differentiation of neural stem cells（NSCs） from rat hippocampus after intrahippocampus transplantation of Alzheimer＇ s disease （AD） rat. Methods ： A total of 40 SD rats were randomly divided into control group,AD group,and 2,4,6 weeks transplantation groups,8 in each group. NSCs were isolated from the dentate gyrus of hippoeampus of newborn rats,and labeled with Hoechst 33258. Rats of tranplantation groups were prepared to be AD model, and 7 d later, were grafted with NSCs into the hippocampus. 2,4 or 6 weeks post transplantation, the behavioral testing were performed using Y-maze trial, and NF-200 and GFAP in cells labeled with Hocchst33258 detected using immunofluorescence and synaptophysin were detected by immunohistochcmistry. Results： 2 weeks after transplantation,GFAP and NF-200 were not detected. 4, 6 weeks after transplantation, approximately 1% cells labeled with Hocchst33258 expressed GFAP, while 10% expressed NF-200. There were significant differences in Synaptophysin expression among the 5 groups （ F = 47.52,P 〈 0. 05 ） , the synaptophysin expression in AD group was significantly lower than that of the control, while those of 2,4,6 week transplantation groups were significantly higher than those of control and AD groups （ P 〈 0.05 ）. There were significant differences in learning and memory capacity among the 5 groups （ F = 63.52,24.36, P 〈 0.05 ）. Compared with control group, the ability of learning and memory in AD group decreased remarkably（P 〈 0.05 ） ,while comparing with AD group, those of 2,4,6 week transplantation groups enhanced obviously （P 〈 0.05）. Conclusion： NSCs grafted in the brain may differentiate into neurons and astrocytes, promote the synapse to rebuild and improve learning and memory ability.