BMSCs脑内移植改善AD小鼠学习记忆功能的分子机制研究  

Molecular mechanism of BMSC intracerebral transplantation in improving learning and memory abilities of AD mice

作　　者：范冲竹 李安[1] 黄翠芹[1] 甘丹卉[1] 李勤[1] 赵佳仪 王珍[1] 朱丽红[1] 陆大祥[1] 

机构地区：[1]暨南大学医学院病理生理学系脑科学研究所国家中医药管理局三级科研实验室,广东广州510632

出　　处：《中国病理生理杂志》2017年第11期1921-1931,共11页Chinese Journal of Pathophysiology

基　　金：国家自然科学基金资助项目(No.81471236;No.81371442)

摘　　要：目的:观察骨髓间充质干细胞(BMSCs)脑内移植对阿尔茨海默病(AD)小鼠学习记忆能力及病理改变的影响,并对其分子机制进行探讨。方法:将C57/BL6野生型(WT)小鼠和C57/BL6 APP/PS1转基因(Tg)小鼠随机分为4组:WT/PBS组、WT/BMSCs组、Tg/PBS组及Tg/BMSCs组,侧脑室注射法将PBS或BMSCs注入小鼠脑内。术后第3天起进行持续8 d的Morris水迷宫实验以检测小鼠认知能力。术后第10天取材,组织免疫荧光染色检测小鼠脑内小胶质细胞的激活;real-time PCR检测CX3C趋化因子配体1(CX3CL1)、CX3C趋化因子受体1(CX3CR1)、IL-1β、TNF-α、Nurr1、YM1、胰岛素降解酶(IDE)和基质金属蛋白酶9(MMP9)的mRNA表达;ELISA检测脑组织匀浆CX3CL1和Aβ42的含量;Western blot检测突触后致密蛋白95(PSD95)、突触小泡蛋白(SYP)、p85和p110蛋白表达以及Akt磷酸化水平的变化。结果:术后第10天,在APP/PS1小鼠海马区附近观察到移植的BMSCs。水迷宫实验结果显示,与WT/PBS组小鼠相比,Tg/PBS组小鼠逃避潜伏期明显延长(P<0.01),BMSCs移植治疗后APP/PS1小鼠逃避潜伏期明显缩短(P<0.05);与Tg/PBS组相比,Tg/BMSCs组CX3CL1在海马区的mRNA水平(P<0.01)及皮质区的蛋白水平(P<0.05)明显增加;BMSCs移植可以促进WT和Tg小鼠脑内小胶质细胞的激活,同时M2型小胶质细胞表面标志物YM1的mRNA表达上调(P<0.05)。Tg/PBS组与WT/PBS组相比,皮质区和海马区TNF-α的mRNA表达明显升高(P<0.05),皮质区Nurr1的mRNA表达降低(P<0.01);而与Tg/PBS组相比,Tg/BMSCs组皮质区的TNF-α(P<0.01)mRNA表达降低,CX3CR1和Nurr1的mRNA表达明显上调(P<0.05),海马区TNF-α和IL-1β的mRNA明显下调(P<0.05),CX3CR1和Nurr1的mRNA表达明显增加(P<0.05)。此外,Tg/BMSCs组的PSD95、p85和p110蛋白表达及Akt的磷酸化水平均较Tg/PBS组明显增加(P<0.05)。与Tg/PBS组比,BMSCs移植降低了APP/PS1小鼠脑内Aβ42蛋白的水平(P<0.05),增加了海马区Aβ清除相关酶IDE和MMP9的表达(P<0.05)。结论:BMSCs�AIM：To investigate the effect of bone marrow mesenchymal stem cell（BMSC） transplantation on learning and memory abilities and pathological changes of Alzheimer disease（AD） mice and the molecular mechanisms.METHODS：C57/BL6 wild-type（WT） and transgenic（Tg） mice were randomly divided into 4 groups：WT/PBS group,WT/BMSCs group,Tg/PBS group and Tg/BMSCs group.The mice were administered with PBS or BMSCs via intracerebroventricular injection.Spatial learning and memory abilities of the mice were evaluated by Morris water maze test on the3 rd day after surgery.Real-time PCR was applied to detect the mRNA expression of CX3 C chemokine ligand 1（CX3 CL1）,CX3 C chemokine receptor 1（CX3 CR1）,IL-1β,TNF-α,Nurr1,YM1,insulin-degrading enzyme（IDE）and matrix metalloproteinase 9（MMP9）.The protein levels of CX3 CL1 and Aβ42 were measured by ELISA.Western blot was used to detect the protein expression of postsynaptic density protein 95（PSD95） and synaptophysin（SYP）.RESULTS：The transplanted BMSCs were observed near the hippocampus of APP/PS1 mice on the 10 th postoperative day.The escape latency of the mice in Tg/PBS group was significantly longer than that in the WT/PBS mice（P 〈 0.05）.Compared with Tg/PBS group,the escape latency of Tg/BMSCs group was significantly shorter（P 〈 0.05）,and the mRNA and protein levels of CX3 CL1 in Tg/BMSCs group were significantly higher than those in Tg/PBS group（P 〈 0.01）.The results of immunohistofluorescence staining showed that BMSC transplantation promoted the activation of microglia in the brain of WT and Tg mice.The mRNA expression of YM1 was up-regulated in WT/BMSCs group and Tg/BMSCs group（P 〈 0.05）.Compared with WT/PBS mice,the mRNA expression of TNF-α in the cortex and hippocampus of Tg/PBS group was significantly increased（P 〈 0.05）,and the mRNA expression of Nurr1 in the cortex was significantly decreased（P 〈 0.01）.Meanwhile,the mRNA expression of TNF-α in the cortex of Tg/BMSCs mice was decreased（P �

关 键 词：骨髓间充质干细胞 CX3C趋化因子配体1 阿尔茨海默病 神经炎症 神经保护 

分 类 号：R741[医药卫生—神经病学与精神病学] R363[医药卫生—临床医学]