中国神经再生研究(英文版)

中国神经再生研究(英文版) ›› 2019, Vol. 14 ›› Issue (4): 658-665.doi: 10.4103/1673-5374.247469

• 原著:退行性病与再生 • 上一篇    下一篇

Aβ前体蛋白突变能改变阿尔茨海默病的病理进程

  

  • 出版日期:2019-04-15 发布日期:2019-04-15
  • 基金资助:

    中国国家自然科学基金项目（81671268），科技部项目（2013YQ03059514），教育部神经退行性疾病重点实验室项目（2015SJBX05，2015SJZS01）

Mutations of beta-amyloid precursor protein alter the consequence of Alzheimer’s disease pathogenesis

Nuo-Min Li 1 , Ke-Fu Liu 1 , Yun-Jie Qiu 1 , Huan-Huan Zhang 1 , Hiroshi Nakanishi 2 , Hong Qing 1   

  1. 1 School of Life Science, Beijing Institute of Technology, Beijing, China
    2 Department of Aging Science and Pharmacology, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
  • Online:2019-04-15 Published:2019-04-15
  • Contact: Hong Qing, MD, hqing@bit.edu.cn
  • Supported by:

    This study was funded by the National Natural Science Foundation of China, No. 81671268 (to HQ); and partially supported by a grant from the Ministry of Science and Technology of China, No. 2013YQ03059514 (to HQ); and a grant from Key Laboratory for Neurodegenerative Disease of Ministry of Education of China, No. 2015SJBX05 (to HQ), 2015SJZS01 (to HQ).

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摘要：

阿尔茨海默病在病理学上定义为Aβ在细胞外积累，约有25种Aβ前体蛋白的突变是致病性的，可导致常染色体显性阿尔茨海默病。但迄今为止，Aβ前体蛋白突变对Aβ生成影响的作用机制尚不清楚。为探索阿尔茨海默病中Aβ前体蛋白突变的机制帮助了解阿尔茨海默病的发病机制，实验将A673T，A673V，E682K，E693G和E693Q五种Aβ前体蛋白突变共转染至HEK细胞系中，以Western blot检测细胞中C20，BACE1，PSEN1的表达水平，以ELISA检测Aβ1-40和Aβ1-42水平，以液相二级质谱检测Aβ前体蛋白的裂解肽VVIAT，FLF，ITL，VIV，IAT，VIT，TVI和VVIA，以免疫荧光反应检测Aβ前体蛋白和EEA1的免疫阳性反应。结果显示：（1）保护性突变A673T通过下调IAT水平和上调VVIA来降低Aβ42/Aβ40的发生率；（2）致病性突变A673V，E682K和E693Q通过增加CTF99，Aβ42，Aβ40和IAT水平，降低VVIA水平，促进Aβ42/Aβ40的发生；（3）致病性E693G突变由于抑制了γ-分泌酶的活性，对Aβ42/Aβ40的比例没有显著影响；（4）Aβ前体蛋白中的突变可以改变蛋白在从细胞表面到早期内体的分布；（5）实验结果说明Aβ前体蛋白突变可以通过影响长Aβ裂解途径来加速Aβ的产生，增加Aβ42/Aβ40的比例，最终导致阿尔茨海默病的发生。

orcid: 0000-0003-0216-4044(Hong Qing)

关键词: 阿尔茨海默病, A&beta, 前体蛋白, A&beta, A&beta, 前体蛋白突变, 液相二级质谱, 细胞定位, 长A&beta

Abstract:

Alzheimer’s disease is pathologically defined by accumulation of extracellular amyloid-β (Aβ). Approximately 25 mutations in β-amyloid precursor protein (APP) are pathogenic and cause autosomal dominant Alzheimer’s disease. To date, the mechanism underlying the effect of APP mutation on Aβ generation is unclear. Therefore, investigating the mechanism of APP mutation on Alzheimer’s disease may help understanding of disease pathogenesis. Thus, APP mutations (A673T, A673V, E682K, E693G, and E693Q) were transiently co-transfected into human embryonic kidney cells. Western blot assay was used to detect expression levels of APP, beta-secretase 1, and presenilin 1 in cells. Enzyme-linked immunosorbent assay was performed to determine Aβ1–40 and Aβ1–42 levels. Liquid chromatography-tandem mass chromatography was used to examine VVIAT, FLF, ITL, VIV, IAT, VIT, TVI, and VVIA peptide levels. Immunofluorescence staining was performed to measure APP and early endosome antigen 1 immunoreactivity. Our results show that the protective A673T mutation de-creases Aβ42/Aβ40 rate by downregulating IAT and upregulating VVIA levels. Pathogenic A673V, E682K, and E693Q mutations promote Aβ42/Aβ40 rate by increasing levels of CTF99, Aβ42, Aβ40, and IAT, and decreasing VVIA levels. Pathogenic E693G mutation shows no significant change in Aβ42/Aβ40 ratio because of inhibition of γ-secretase activity. APP mutations can change location from the cell surface to early endosomes. Our findings confirm that certain APP mutations accelerate Aβ generation by affecting the long Aβ cleavage pathway and increasing Aβ42/40 rate, thereby resulting in Alzheimer’s disease.

Key words: nerve regeneration, Alzheimer’s disease, β-amyloid precursor protein, amyloid β, APP mutations, liquid chromatography-tandem mass chromatography, cellular localization, long Aβ, neural regeneration