外源性H_2 S通过调节β-位淀粉样前体蛋白裂解酶1表达对PC12细胞APP/Aβ代谢的影响  

Effect of Exogenous Hydrogen Sulfide on Amyloid Precursor Protein /|$-amyloid Processing Through Regulating Expression of p-site Amyloid Precursor Protein Cleaving Enzyme 1in Pheochromocytoma Cells

作　　者：代政伟[1] 孟涛[1] 晏勇[1] 

机构地区：[1]重庆医科大学附属第一医院神经内科重庆市神经病学重点实验室,重庆400016

出　　处：《世界科技研究与发展》2011年第1期128-131,共4页World Sci-Tech R&D

基　　金：重庆市医学科研计划项目基金(2010-1-17)

摘　　要：目的观察外源性硫化氢对嗜铬细胞瘤细胞β-位淀粉样前体蛋白裂解酶1(BACE1)的调节作用,进而探讨其对淀粉样前体蛋白/β-位淀粉样蛋白代谢途径的影响。方法用硫氢化钠作外源性H_2S供体,实验设空白对照组、NaHS 50 μmol/L组、NaHS 100μmol/L组和NaHS 200 μmol/L组,按分组浓度处理PC12细胞24 h后,RT-PCR和Western blot法检测细胞内BACE1 mRNA及蛋白表达,并用Western blot法继而检测APP代谢过程中关键蛋白APP、C99、C83表达变化,ELISA法检测细胞培养液中Aβ40和Aβ42水平。结果 NaHS在实验浓度范围内从基因与蛋白两个水平上呈剂量依赖性下调BACE1表达,并下调C99、Aβ40和Aβ42蛋白表达,上调C83蛋白,各NaHS组分别与对照组比较,差别均有统计学意义(P<0.05),而对APP蛋白表达没有影响,各组间比较差别无显著性(P>0.05)。结论外源性H_2S具有通过调节PC12细胞BACE1表达下调APP/Aβ代谢的作用。Objective To observe the effect of exogenous hydrogen sulfide on β-site amyloid precursor protein cleaving enzyme 1 （BACE1） and the amyloid precursor protein/β-amyloid （APP/Aβ） processing in pheochromocytoma （PC12） cells. Methods PCI2 cells were divided into 4 groups：blank control group, NariS 50 μmol/L group, NariS 100 μmol/L group and NaHS 200 μmol/L group. Four groups were treated with 0,50,100 or 200 μmoL/L sodium hydrosulfide（ NariS, the homer of exogenous hydrogen sulfide）, respectively. RT-PCR and Western blot were used to detect the levels of BACE1 mRNA and protein expression. Western blot was also used to detect the levels of key proteins in the metabolic process of APP, including APP, C99 and C83. ELISA method was used to analyze the levels of Aβ40 and Aβ42 in cellular cuhure medium. Results Compared with blank control group,NariS significantly and dose-dependently decreased BACE1 mRNA and protein expression within experimental concentration rages in NariS groups. So did the C99, Aβ40 and Aβ42 proteins （ all P 〈 0. 05 ）. On the contrary, C83 protein significantly increased （P 〈 0. 05 ）, with no significant change （P 〉 0. 05 ） to the APP protein. Conclusion The expression of BACE1 may be effected by the exogenous hydrogen,which may cause the down-regulation of the APP/Aβ processing.

关 键 词：外源性硫化氢 β-淀粉样前体蛋白裂解酶1 淀粉样前体蛋白分泌酶类 嗜铬细胞瘤细胞 阿尔茨海默病 

分 类 号：R749.16[医药卫生—神经病学与精神病学]