β-淀粉样蛋白和drebrin在培养的APP／PS1转基因小鼠神经元中的表达

Expressions of β-amyloid protein and drebrin in cultured neurons of the APP/PS1 transgenic mouse

目的： 探讨阿尔茨海默病（AD）脑内β-淀粉样蛋白（Aβ）积聚与树突棘蛋白drebrin表达变化之间的关系.方法： 采用免疫细胞化学、ELISA和免疫印迹法等方法检测大脑皮层原代培养的APP/PS1转基因小鼠的神经元和同种野生型（WT）小鼠的神经元Aβ和drebrin的表达.结果： 培养至12d （days in vitro）时,可见Aβ在APP/PS1神经元胞体内聚集,培养基内的Aβ水平也同时升高;此期神经元内drebrin斑点状免疫反应产物分布较为稀疏,drebrin的表达水平下降.18d时,Aβ在胞体内聚集的基础上,向突起内延伸,培养基内的Aβ水平进一步升高;drebrin的表达则明显下降.结论： 原代培养的APP/PS1小鼠神经元内Aβ积聚的同时,树突棘蛋白drebrin的表达下降.提示AD脑内Aβ积聚可能是影响树突棘蛋白drebrin表达的因素之一.

Objective： To investigate the relationship between β-amyloid protein （Aβ） accumulation and the expression change of the dendritic spine protein drebrin in the brain of Alzheimer＇s disease （AD）. Methods： The expressions of Aβ and drebrin in primary cultured neurons from the cerebral cortex of the APP/PS1 transgenic and wild type mice by means of immunocy- tochemistry, ELISA and Western blotting. Results： Compared with control neurons from the wild type mice, the Aβ was observed to be gathered in perikarya of the neurons of the APP/PS1 transgenic mice and the Aβ level was increased in the same time in culture medium at 12 days in vitro ; meanwhile, the irnmunoreactive spot of the drebrin was rarely seen, the ex- pression level of drebrin was decreased. In 18 d in vitro, the pericaryon gathered Aβ was observed to be spread into the processes, and the Aβ level in the culture medium was obviously increased; the expression level of drebrin was significantly decreased. Conclusion： These results indicated that accumulation of the Aβin the primary cultured APP/PS1 neurons followed by a decreased expression of the drebrin, which suggested that Aβ accumulation might be one of the reasons of decrease of the drehrin in the brain of AD.