SH-SY5Y细胞α7尼古丁受体基因抑制对APP代谢的影响

Influence of inhibiting α7 nicotinic acetylcholine receptor gene expression on the metabolism of APP in SH-SY5Y cells

目的采用RNA干扰技术抑制神经母细胞瘤细胞(SH-SY5Y细胞)中α7神经型尼古丁乙酰胆碱受体(nAChR)基因表达,了解对β淀粉样前体蛋白(APP)代谢中的γ-分泌酶两个重要组分早老蛋白(PS)及单过性跨膜蛋白(NCT)水平的影响。方法 SH-SY5Y细胞转染针对α7nAChR的小干扰RNA(siRNA),用实时PCR法和Western印迹法分别测定细胞中α7 nAChR、PS及NCT在mRNA和蛋白表达水平的变化。结果转染α7 nAChR siRNA后,与对照组相比,α7 nAChR mRNA及蛋白表达水平明显降低;PS蛋白mRNA及蛋白水平均升高,而NCT水平无明显变化。结论α7 nAChR基因表达抑制后γ-分泌酶组分之一PS的水平明显升高,这种改变可能与α7 nAChR基因表达抑制后β-淀粉样蛋白(Aβ)的产生增多有关,可能与阿尔茨海默氏病(AD)的发病有一定的关系。

Objective To investigate the influence of inhibiting α7 neuronal nicotinic acetylcholine receptor （nAChR） by small interference RNA （siRNA） on the level of presenilin （PS） and nicastrin （NCT）, the two components of γ-secretase in SH-SY5Y cells. Methods The siRNA of α7 nACbR was transfeeted into SH-SY5Y cells, and the expressions of α7 nAChR, PS and NCT mRNA and protein were detected by real-time PCR and Western blotting respectively. Results Compared with controls, the mRNA and protein levels of α7 nAChR in the SH-SY5Y cells transfected with the α7 nAChR siRNA were significantly decreased. Expressions of PS mRNA and protein levels were increased, while there was no difference in NCT level. Conclusions The inhibited α7 nAChR mRNA induced by siRNA may obviously increase the level of PS, the main component of γ-secretase, which may connect to the increased production of Aβ induced by the inhibiting of α7 nAChR, and might be connected with the pathogenesis of AD.