人骨髓间充质干细胞移植对缺氧缺血性脑病新生大鼠学习记忆功能的影响

目的 研究人骨髓间充质干细胞(hMSC)经脑室移植后对新生鼠缺氧缺血性脑病(HIE)模型的治疗作用及观察植入细胞的存活、迁移及对大鼠远期学习记忆功能的影响.方法 体外分离、扩增正常人骨髓间充质干细胞,移植前用CM-DiI标记.7日龄新生SD大鼠随机分为假手术组(n=10)、HIE组(n=10)、HIE-hMSC组(n=20).HIE-hMSC组:建立HIE模型后72 h,将hMSC(1×106细胞/μl)5μl采用立体定向移植到乳鼠侧脑室.大鼠6周龄时行Morris水迷宫实验检测其学习记忆功能.取大鼠脑组织制作快速冰冻切片直接在荧光显微镜下观察移植细胞的存活及迁移.部分脑组织制成石蜡切片,HE染色计数海马CA1区存活神经元数.结果hMSC移植到大鼠脑室后能存活至少5周,移植后2周细胞沿移植针道呈条索状分布,并发出红色荧光;移植后5周,细胞分布较前稀疏,损伤组织中可见移植细胞.大鼠的空间学习记忆功能有所改善,水迷宫平均逃逸潜伏期HIE-hMSC组(45.5±16.5) s较HIE组(74.5±7.5)s显著缩短(P<0.05),原平台像限的搜索时间HIE-hMSC组(47±10)s显著长于HIE组(36±8)s(P<0.01).HIE-hMSC组左侧海马CA1区存活神经元数为(94±23)个/mm,较HIE组(61±12)个/mm显著增多(P<0.05).结论 hMSC 经脑室移植到缺氧缺血性脑病的新生SD乳鼠后,hMSC能存活至少5周,并迁移至损伤脑组织.大鼠的远期学习记忆功能有所改善,海马CA1区存活神经元数增多.

Influence on learning and memory in neonatal rats with hypoxic-ischemic encephalopathy by transplantation of human mesenchymal stem cells

Objective To evaluate the transplantation of human mesenchymal stem cells (hMSCs) into cerebral ventricle of neonatal rats with hypoxic-ischemic encephalopathy (HIE) ,to investigate the survival and migration of hMSCs,and the long-term effects of hMSCs on scores of learning and memory in rats. Method hMSCs were purified by culture-expanded in vitro and then labeled with the fluorescent tracker CM-DiI. Postnatal 7-day newborn rats were randomly divided into three groups:sham operation (n=10),HIE (n=10),and HIE-hMSCs (n=20).HIE-hMSCs rat model was established as follows: 72 h after hypoxic-ischemia,5 μl hMSCs(1×106 ceus/μl)were injected into the left cerebral ventricle of rats by using stereotactic instrument. All the animals were tested for the spatial learning and memory ability in the Morris water maze at week 6. The rats were decapitated and their brain tissues were sectioned to identify the transplanted cells under fluorescent microscope and to examine survival neurons in hippocampal CA1 zone by HE staining. Results hMSCs survived in rat brain for exceeding 5 weeks. Two weeks after transplantation,the marked hMSCs gave out red lights spreading along the two sides of needle canal. Five weeks after transplantation,the distribution of cells near the canal was sparser than that of 2 weeks .The spatial learning and memory ability of the HIE-hMSCs group were improved. The average escape latency of Morris water maze in HIE-hMSCs group (45.5±16.5) s was significantly shorter than that in HIE group(74.5±7.5)s(P<0.05).The swimming time spent in the target quadrant in HIE-hMSCs group(47±10)s was obviously longer than that in HIE group(36±8)s(P<0.01). The survival neurons of hippocamal CA1 zone in HIE-hMSCs group(94±23)neuron/mm were more than those in HIE group(61±12) neuron/mm(P<0.05). Conclusions The implanted hMSCs can survive at least for 5 weeks,and migrate in the brain of neonatal rats with HIE. hMSCs transplantation can improve the long-term learning-memory deficits and the survival neurons of hippocamal CA1 zone in rats with HIE.