APPswe/PS1dE9转基因小鼠小脑内突触素及BDNF/Trk-B蛋白表达的变化

摘要

Objective:To observe the expressions of synaptophysin and BDNF/Trk-B in cerebellum of APPswe/PS1dE9 transgenic mice.Methods:The healthy 9-month old APP/PS1 male mice (n1) and the same wild type male mice(n2) were divided into two groups,APP/PS1 group and wild-type(WT) group.The expressions of synaptophysin and brain-derived neurotrophic factor/tyrosine kinase B (BDNF/Trk-B) in cerebellum were determined by Western blot (n1 =6;n2 =6) and immunohistochemical(n1 =4;n2 =4).The possible synaptic changes in APP/PS1 group were observed by using electron microscopy.Results:Compared with WT group,the expressions of synaptophsin and BDNF/Trk-B in cerebellum were decreased in APP/PS1 group.Increased width of the synaptic cleft and decreased thickness of postsynaptic density were also observed.Conclusion:In APP/PS1 group,expressions of synaptophsin and BDNF/Trk-B in cerebellum were decreased;changes in ultrastructure of synapses seemed to be widespread alterations.These findings suggest a possible association between expression of BDNF/TrkB and synaptic plasticity in AD cerebellum.%目的:观察APP/PS1转基因小鼠小脑突触素及BDNF/Trk-B蛋白表达变化.方法:选用9月龄APP/PS1雄鼠(n1)和同窝对照野生型WT雄鼠(n2).采用Western blot(n1=6;n2=6)、免疫组化(n1 =4;n2=4)两种方式定量、定位测定小脑组织功能活性依赖蛋白突触素、脑源性神经营养因子(BDNF)和其高亲和力受体(Trk-B)的蛋白表达.用透射电镜观察小脑皮质突触超微结构变化(n1=2;n2=2).结果:与WT组相比,APP/PS1组小脑皮质内突触素、BDNF/Trk-B表达明显减少;突触间隙增宽,突触后致密区变薄,密度降低.结论:APP/PS1小鼠小脑皮质中突触素、BDNF/Trk-B蛋白含量均明显降低,突触超微结构也发生明显改变,提示AD小、脑突触数量及形态变化可能与BDNF合成及释放减少有关.