Identification of Small Peptides in Human Cerebrospinal Fluid upon Amyloid-β Degradation
Identification of Small Peptides in Human Cerebrospinal Fluid upon Amyloid-β Degradation
复制标题
DOI：
10.1159/000453358
复制
发表时间：
2017-01-01
影响因子：
3
通讯作者：
Okochi, Masayasu
中科院分区：
文献类型：
--
作者：
Mizuta, Naoki;Yanagida, Kanta;Okochi, Masayasu
背景：阿尔茨海默病患者脑内类Arnyloid-P（AP）降解是阐明疾病发病机制的关键焦点。然而，AP在人脑中降解的机制仍不清楚。目的：本研究旨在定量人脑脊液（CSF）中A3降解后产生的小C末端AP片段的水平。方法：采用高压液相色谱法从人脑脊液中分离纯化小肽组分。采用液相色谱-串联质谱法对AP C末端的降解产物进行鉴定和测定。分析了用I3 APP瑞典变体（sw（3APP））转染的培养细胞的条件培养基中AP的C末端片段。还分析了过表达sw PAPP的PS1 I213 T敲入转基因小鼠脑中的这些片段。结果如下：在人CSF、转基因小鼠脑和培养细胞的条件培养基中鉴定了由AP 40裂解产生的肽片段GGW和GW。相对于A1340水平，GGW和GW水平分别为7.6 ± 0.81和1.5 ± 0.18%，在人CSF中。GGW片段的水平并没有增加的基因编码脑啡肽酶和胰岛素降解酶的培养细胞的引入。结论：我们的研究结果表明，大量的A1340在人脑中通过脑啡肽或胰岛素降解酶的非依赖性途径降解。(C)2017 S. Karger AG，巴塞尔
Background: Arnyloid-P (AP) degradation in brains of Alzheimer disease patients is a crucial focus for the clarification of disease pathogenesis. Nevertheless, the mechanisms underlying AP degradation in the human brain remain unclear. Objective: This study aimed to quantify the levels of small C-terminal AP fragments generated upon A3 degradation in human cerebrospinal fluid (CSF). Methods: A fraction containing small peptides was isolated and purified from human CSF by high-pressure liquid chromatography. Degradation products of AP C termini were identified and measured by liquid chromatography-tandem mass spectrometry. The C terminal fragments of AP in the conditioned medium of cultured cells transfected with the Swedish variant of I3APP (sw (3APP) were analyzed. These fragments in brains of PS1I213T knock-in transgenic mice, overexpressing sw PAPP, were also analyzed. Results: The peptide fragments GGW and GW, produced by the cleavage of AP40, were identified in human CSF as well as in the brains ofthe transgenic mice and in the conditioned medium of the cultured cells. Relative to A1340 levels, GGW and GW levels were 7.6 0.81 and 1.5 0.18%, respectively, in human CSF. Levels of the GGW fragment did not increase by the introduction of genes encoding neprilysin and insulin-degrading enzyme to the cultured cells. Conclusion: Our results indicate that a substantial amount of A1340 in human brains is degraded via a neprilysin- or insulin-degrading enzyme-independent pathway. (C) 2017 S. Karger AG, Basel