Novel Blood-Derived Extracellular Vesicle-Based Biomarkers in Alzheimer's Disease Identified by Proximity Extension Assay
Novel Blood-Derived Extracellular Vesicle-Based Biomarkers in Alzheimer's Disease Identified by Proximity Extension Assay
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DOI：
10.3390/biomedicines8070199
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发表时间：
2020-07-01
期刊：
影响因子：
4.7
通讯作者：
Pedersen, Shona
中科院分区：
文献类型：
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作者：
Ellegaard Nielsen, Jonas;Sofie Pedersen, Kamilla;Pedersen, Shona
缺乏易于获得的阿尔茨海默氏痴呆 (AD) 生物标志物，并且已建立的临床标志物的适用性有限。血液是生物标志物发现的常见生物流体，细胞外囊泡 (EV) 可以为探索 AD 相关生物标志物提供基质。因此，我们研究了血浆和 EV 中与神经和炎症过程相关的蛋白质。通过邻近延伸分析 (PEA)，在 AD 患者 (n = 10)、轻度认知障碍 (MCI，n = 10) 和健康对照 (n = 10) 患者的血浆和 EV 中测量了 182 种蛋白质。血浆来源的 EV 在 4℃、1 小时、20,000x g 下富集，并使用纳米颗粒跟踪分析 (NTA)、蛋白质印迹和免疫标记透射电子显微镜 (IEM) 进行确认。通过蛋白质印迹和 IEM 证实 CD9(+) EV 的存在。 NTA 未检测到颗粒浓度或大小的组间差异。然而，在受试者中观察到显着的蛋白质谱，特别是 EV。几种蛋白质及其比例可以区分认知受影响的个体和健康个体。对于血浆 TGF-α | CCL20（AUC = 0.96，95% CI = 0.88-1.00，p = 0.001）和 EV CLEC1B | CCL11（AUC = 0.95，95% CI = 0.86-1.00，p = 0.001）显示出诊断能力。使用 PEA，我们确定了能够区分健康对照和 AD 患者的蛋白质谱。 EV 提供了仅在血浆中观察不到的与 AD 相关的额外生物信息。
Easily accessible biomarkers for Alzheimer's dementia (AD) are lacking and established clinical markers are limited in applicability. Blood is a common biofluid for biomarker discoveries, and extracellular vesicles (EVs) may provide a matrix for exploring AD related biomarkers. Thus, we investigated proteins related to neurological and inflammatory processes in plasma and EVs. By proximity extension assay (PEA), 182 proteins were measured in plasma and EVs from patients with AD (n = 10), Mild Cognitive Impairment (MCI, n = 10), and healthy controls (n = 10). Plasma-derived EVs were enriched by 20,000x g, 1 h, 4 degrees C, and confirmed using nanoparticle tracking analysis (NTA), western blotting, and transmission electron microscopy with immunolabelling (IEM). Presence of CD9(+) EVs was confirmed by western blotting and IEM. No group differences in particle concentration or size were detected by NTA. However, significant protein profiles were observed among subjects, particularly for EVs. Several proteins and their ratios could distinguish cognitively affected from healthy individuals. For plasma TGF-alpha | CCL20 (AUC = 0.96, 95% CI = 0.88-1.00, p = 0.001) and EVs CLEC1B | CCL11 (AUC = 0.95, 95% CI = 0.86-1.00, p = 0.001) showed diagnostic capabilities. Using PEA, we identified protein profiles capable of distinguishing healthy controls from AD patients. EVs provided additional biological information related to AD not observed in plasma alone.