Ndfip1在APP/PS1转基因小鼠脑内表达变化及其对老年斑沉积的影响

Expression of Ndfip1 in APP/PS1 transgenic mice brains and its effect on senile plaque deposition

目的观察Ndfip1在APP/PS1转基因小鼠大脑皮质和海马的分布和表达变化,以及Ndfip1与Aβ老年斑的定位关系;检测Ndfip1过表达对APPsw细胞APP代谢及Aβ分泌量的影响,明确Ndfip1对APP代谢及Aβ分泌的调控作用。方法应用免疫荧光三标共聚焦技术观察Ndfip1在APP/PS1转基因小鼠大脑皮质和海马的分布,以及Ndfip1与Aβ老年斑的共定位情况。应用蛋白印迹技术检测APP/PS1转基因小鼠大脑皮质和海马中Ndfip1蛋白含量以及转染后细胞内APP695蛋白含量。应用ELISA试剂盒测量细胞培养基中Aβ1-42的水平。结果 APP/PS1转基因小鼠大脑皮质可见Ndfip1阳性表达;海马内也可见Ndfip1阳性表达。Ndfip1分布于锥体神经细胞的核周质和突起内,在Aβ阳性老年斑中可见Ndfip与Aβ共定位表达。APP/PS1转基因小鼠大脑皮质和海马内Ndfip1蛋白含量明显低于对照组。Ndfip1过表达组细胞内APP695含量明显下调,Aβ1-42分泌量减少。结论 Ndfip1可能通过负性调控APP代谢和Aβ的分泌,影响Aβ沉积及老年斑形成,参与阿尔茨海默症的病理过程。

Objective The expression of Ndfip1,as well as the relationship between Ndfip1 and Aβsenile plaques,were observed in the cerebral cortex and hippocampus of APP/PS1 transgenic mice. The effects on APP metabolism and Aβ secretion were detected in APPsw cells with Ndfip1 overexpressed. To clarify the regulation of Ndfip1 to APP metabolism and Aβ secretion. Methods The expression of Ndfip1,as well as the co-localization of Ndfip1 and Aβ senile plaques,were observed by immunofluorescence three-label confocal technology. The protein contents of Ndfip1 and APP695 were detected by western blot. The levels of Aβ1-42 in cell medium were detected by ELISA. Results Ndfip1 was expressed in the cortex and hippocampus of APP/PS1 transgenic mice,which were mostly located in the cytoplasm and protrusions of pyramidal neurons. Ndfip and Aβ were co-localized in the Aβ-positive senile plaques.The protein content of Ndfip1 in APP/PS1 transgenic mice was lower than that of the control group. The protein content of APP695 and secretion of Aβ1-42 decreased in cells with the Ndfip1 overexpressed.Conclusions Ndfip1 may be involved in the pathological process of Alzheimer’s disease by negatively regulating APP metabolism and Aβ secretion,affecting the deposition of Aβ and formation of senile plaque.