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

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。

Expressions of synaptophysin and BDNF/Trk-B in cerebellum of APPswe/PS1dE9 transgenic mice

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.