胰岛素样生长因子结合蛋白4转基因小鼠脑内细胞分化的研究  

Neural cell differentiation in the brain of insulin-like growth factor binding protein 4 transgenic mouse

作　　者：张贺 勾荣彬 牛含虚 孙晓红[1] 徐群渊[1] 段德义[1] Zhang He;Gou Rongbin;Niu Hanxu;Sun Xiaohong;Xu Qunyuan;Duan Deyi(Department of Neurobiology,School of Basic Medical Sciences,Capital Medical University;Beijing Institute for Barain Disorders;Beijing Center of Neural Regeneration&Repair,Beijing 100069,China)

机构地区：[1]首都医科大学基础医学院神经生物学系,北京脑重大疾病研究院,北京市神经再生修复研究重点实验室,北京100069

出　　处：《首都医科大学学报》2018年第6期910-916,共7页Journal of Capital Medical University

摘　　要：目的研究神经元特异性启动子血小板源性生长因子-β(platelet derived growth factor-β,PDGF-β)介导的胰岛素样生长因子结合蛋白4(insulin-like growth factor binding protein 4,IGFBP4)转基因小鼠脑内神经元和神经胶质细胞分化情况。方法PCR扩增并测序鉴定PDGF-β启动子和IGFBP4 c DNA表达框的整合,Isotropic Fractionator细胞计数法分析海马少突胶质前体细胞比例,Western blotting法分析生后28 d小鼠海马等部位神经元和神经胶质细胞的分化、胰岛素样生长因子-1(insulin-like factor-1,IGF-1)受体通路激活以及细胞存活相关分子表达,Rotarod实验观察小鼠运动能力。结果 IGFBP4 c DNA稳定整合于小鼠基因组,转基因小鼠海马少突胶质前体细胞数目和成熟细胞髓磷脂碱性蛋白(myelin basic protein,MBP)均明显增多,神经元和星形胶质细胞标志物Neu N和胶质纤维酸性蛋白(glial fibrillary acidic protein,GFAP)表达改变不明显; Erk1,2和Akt磷酸化升高,p38的激活不明显; Caspase-3表达下调,β-catenin和Bcl-2表达无明显改变,12月龄小鼠Rotarod运动能力明显增强,其小脑和皮质Neu N表达增多。结论神经元过表达IGFBP4促进小鼠脑少突胶质细胞和神经元的分化。Objective To explore the neuronal and glial differentiation in the brain of the insulin-like growth factor binding protein4(IGFBP4)transgenic mouse in which the gene was driven by a neuron-specific promoter platelet derived growth factor-β(PDGF-β).Methods The integrated expression cassette of PDGF-βpromoter and IGFBP4cDNA was identified using PCR and DNA sequencing.The proportion of oligodendrocyte precursors in the hippocampus was estimated via Isotropic Fractionator.Semi-quantitative analysis of neuronal and glial differentiation,IGF-IR pathway activation,and cell survival-related molecules in the hippocampus at postnatal day28was conducted by Western blotting.Animal behavior was assessed using Rotarod test.Results PDGF-βpromoter and IGFBP4cDNA were stably integrated in the transgenic mouse genome.The number of oligodendrocyte precursors and expression levels of myelin basic protein(MBP)in the hippocampus were significantly increased,neuronal and astrocytic markers NeuN and glial fibrillary acidic protein(GFAP)were not significantly changed in the brain of P28transgenic mice.Phosphorylation levels of Erk1,2and Akt were significantly elevated while p38activation remained unchangeable.Caspase-3expression was significantly down-regulated,β-catenin and Bcl-2levels were not changed.Animal movement on Rotarod was significantly improved,and NeuN expression in the cerebellum and cortex was significantly increased in the transgenic mouse at postnatal month12.Conclusion Over-expression of IGFBP4in neurons promoted oligodendrocytic and neuronal differentiation in the brain of the transgenic mice.

关 键 词：胰岛素样生长因子结合蛋白-4 神经分化 胰岛素样生长因子-Ⅰ型受体信号通路 转基因小鼠 

分 类 号：Q786[生物学—分子生物学]