pEGFP/A2M(FP6)转染神经干细胞海马移植治疗APP/PS1双转基因AD小鼠的实验观察

摘要

Objective: To observe the migration and differentiation of pEGFP/A2M (FP6) transfected neural stem cells (NSCs), the deposits of Aβ in the brain and the change of learning and memory ability of APP/PS1 double transgenic mice of Alzheimer's Disease (AD) after the NSCs were transplanted into the hippocampus. Methods: APP/PS1 transgenic AD mice were randomly divided into four groups: sham operated (SO) group, artificial cerebrospinal fluid (ACSF) group, transfected pEGFP neural stem cell (pEGFP-NSCs) group and transfected pEGFP/A2M(FP6) neural stem cell (pEGFP/A2M(FP6)-NSCs) group. The ACSF, pEGFP-NSCs or pEGFP/A2M (FP6)-NSCs were transplanted into the CA1 region of the hippocampus of the mice. The learning and memory ability of the mice were assessed with Mirror water maze test. The migration and differentiation of pEGFP/A2M(FP6) transfected NSCs and the deposits of Aβ in the brain of the mice were observed by immuno-histochemistry. Results: The latencies of pEGFP/A2M (FP6)-NSCs group and pEGFP-NSCs group were significantly shorter than that in the SO group and ASCF group (P<0.05). The latency of pEGFP/A2M(FP6)-NSCs group was shorter than that in the pEGFP-NSCs group (P<0.05). Anti-Aβ detection showed Aβ deposits in the hippocampus and cortex of pEGFP/A2M(FP6)-NSCs group and pEGFP-NSCs group were surrounded by transplanted NSCs. The amount and average size of Aβ deposits in the hippocampus and cortex of pEGFP/A2M (FP6)-NSCs group were reduced markedly, compared with the other three groups (P<0.05). The expression of Nestin was detecte after transplantation. Immunofluorescent detection indicated that majority of transplanted cells expressed GFAP while only a few cells expressed MAP-2. Conclusion: Transplantation of pEGFP/A2M (FP6)-NSCs into the hippocampal region of APP/PS1 double transgenic AD mice could reduce the Aβ deposits and promote the learning and memory ability. Partial transplanted NSCs will differentiate into neurons or astro-cytes.%目的:携带pEGFP/A2M(FP6)的神经干细胞(NSCs)定向移植到APP/PS1 双转基因AD 小鼠海马内,观察移植细胞的分化、迁移,脑内A茁沉积的变化,以及对AD 小鼠学习记忆功能的影响.方法:APP/PS1 转基因AD 小鼠分为假手术(SO)组、人工脑脊液(ACSF)组、转染pEGFP 的NSCs(pEGFP-NSCs )组及转染pEGFP/A2M(FP6)的NSCs(pEGFP/A2M(FP6)-NSCs )组,移植物小鼠海马CA1 区定位注射,水迷宫实验检测小鼠认知功能,免疫组化观察小鼠脑内移植细胞的分化、迁移及A茁病理变化.结果:pEGFP/A2M (FP6)-NSCs 组和pEGFP-NSCs 组转基因小鼠逃避潜伏期较SO 组及ACSF 组显著缩短(P＜0.05);pEGFP/A2M (FP6)-NSCs 组转基因小鼠逃避潜伏期较pEGFP-NSCs 组缩短(P＜0.05).pEGFP/A2M(FP6) -NSCs 组和pEGFP-NSCs 组转基因小鼠海马及皮质内,部分A茁染色阳性斑块周围可见表达EGFP 的移植细胞.pEGFP/A2M(FP6)-NSCs 组转基因小鼠额叶、海马区域,A茁染色阳性斑块数量和平均面积均较其他3 组显著减少(P＜0.05).移植的NSCs,部分细胞Nestin 染色呈阳性,部分细胞GFAP 染色呈阳性,少数细胞MAP-2 染色呈阳性.结论:移植pEGFP/A2M(FP6)NSCs 到APP/PS1 双转基因AD 小鼠海马,可减少AD 小鼠脑内A茁斑块沉积,部分移植的NSCs 分化为神经元及星形胶质细胞,小鼠的学习记忆功能显著改善.