Department of Pharmacology & Experimental Therapeutics, Boston University School of Medicine, Boston, Massachusetts 02118, United States.
Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02118, United States.
J Proteome Res. 2021 Mar 5;20(3):1733-1743. doi: 10.1021/acs.jproteome.0c00934. Epub 2021 Feb 3.
Extracellular vesicles (EVs) are secreted by any neural cells in the central nervous system for molecular clearance, cellular communications, and disease spread in multiple neurodegenerative diseases, including Alzheimer's disease (AD), although their exact molecular mechanism is poorly understood. We hypothesize that high-resolution proteomic profiling of EVs separated from animal models of AD would determine the composition of EV contents and their cellular origin. Here, we examined recently developed transgenic mice (CAST.), which express familial AD-linked mutations of amyloid precursor protein () and presenilin-1 () in the CAST/EiJ mouse strain and develop hippocampal neurodegeneration. Quantitative proteomics analysis of EVs separated from CAST. and age-matched control mice by tandem mass tag-mass spectrometry identified a total of 3444 unique proteins, which are enriched in neuron-, astrocyte-, oligodendrocyte-, and microglia-specific molecules. CAST.-derived EVs show significant enrichment of Psen1, APP, and Itgax and reduction of Wdr61, Pmpca, Aldh1a2, Calu, Anp32b, Actn4, and Ndufv2 compared to WT-derived EVs, suggesting the involvement of Aβ-processing complex and disease-associated/neurodegenerative microglia (DAM/MGnD) in EV secretion. In addition, Itgax and Apoe, DAM/MGnD markers, in EVs show a positive correlation with and mRNA expression from brain tissue in CAST. mice. These datasets indicate the significant contribution of Aβ plaque and neurodegeneration-induced DAM/MGnD microglia for EV secretion in CAST. mice and shed light on understanding AD pathogenesis.
细胞外囊泡(EVs)是中枢神经系统中任何神经细胞分泌的,用于分子清除、细胞通讯以及多种神经退行性疾病中的疾病传播,包括阿尔茨海默病(AD),尽管其确切的分子机制尚未完全了解。我们假设,对 AD 动物模型中分离的 EV 进行高分辨率蛋白质组学分析,将确定 EV 内容物的组成及其细胞来源。在这里,我们检查了最近开发的转基因小鼠(CAST.),这些小鼠在 CAST/EiJ 小鼠品系中表达淀粉样前体蛋白(APP)和早老素-1(PSEN1)的家族性 AD 相关突变,并发展出海马神经退行性变。通过串联质量标签 - 质谱法对从 CAST. 和年龄匹配的对照小鼠中分离的 EV 进行定量蛋白质组学分析,共鉴定出 3444 种独特的蛋白质,这些蛋白质富含神经元、星形胶质细胞、少突胶质细胞和小胶质细胞特异性分子。与 WT 衍生的 EV 相比,CAST.-衍生的 EV 显示出 Psen1、APP 和 Itgax 的显著富集,以及 Wdr61、Pmpca、Aldh1a2、Calu、Anp32b、Actn4 和 Ndufv2 的减少,表明 Aβ 加工复合物和与疾病相关/神经退行性小胶质细胞(DAM/MGnD)参与 EV 分泌。此外,EV 中的 Itgax 和 Apoe、DAM/MGnD 标志物,与 CAST. 小鼠脑组织中的 和 mRNA 表达呈正相关。这些数据集表明,Aβ 斑块和神经退行性变诱导的 DAM/MGnD 小胶质细胞对 CAST. 小鼠 EV 分泌的显著贡献,并为理解 AD 发病机制提供了线索。