Targeting Endosomal dysfunction as a new source of biomarkers for Alzheimer's disease

将内体功能障碍作为阿尔茨海默病生物标志物的新来源

• 批准号: 10588259
• 负责人: Sabrina Alves Simoes Spassov
• 金额: $ 51.05万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-03-15 至 2026-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10588259
• 关键词: APLP1 gene; Acceleration; Address; Affect; Alzheimer' s Disease; Alzheimer' s disease brain; Alzheimer' s disease pathology; Alzheimer' s disease patient; Alzheimer' s disease risk; Alzheimer’s disease biomarker; Amyloid beta-Protein; Amyloid beta-Protein Precursor; Biological; Biological Assay; Biological Markers; Brain; Cell Adhesion Molecules; Cells; Cellular biology; Cerebrospinal Fluid; Cognitive; Confocal Microscopy; Consensus; Core Protein; Cytopathology; Data; Defect; Development; Diagnostic; Disease; Disease Progression; Electron Microscopy; Endosomes; Enzyme-Linked Immunosorbent Assay; Extracellular Space; Frontotemporal Dementia; Functional disorder; Genes; Genetic; Goals; Histopathology; Human; Image; Knock-out; Knockout Mice; Lewy Body Disease; Link; Liquid Chromatography; Measures; Modeling; Mus; Mutant Strains Mice; Mutation; Nerve Degeneration; Neurodegenerative Disorders; Neurofibrillary Tangles; Neurons; Parkinson Disease; Participant; Pathogenicity; Pathology; Pathway interactions; Patients; Peripheral; Plasma; Preparation; Proteins; Proteomics; Sampling; Senile Plaques; Source; Specificity; Technology; Testing; Therapeutic Intervention; Transgenic Mice; Western Blotting; amyloid pathology; beta secretase; beta-site APP cleaving enzyme 1; biomarker discovery; biomarker identification; biomarker panel; de novo mutation; design; drug discovery; exosome; genetic risk factor; human pluripotent stem cell; mouse model; mutant; nervous system disorder; potential biomarker; prodromal Alzheimer' s disease; protein expression; rare variant; receptor; specific biomarkers; tandem mass spectrometry; tau Proteins; trafficking

Endosomal dysfunction is a well-accepted cell biological feature in Alzheimer’s disease (AD). However, biomarkers reflecting endosomal traffic defects are still lacking. Current imaging and cerebrospinal fluid (CSF) AD biomarkers focus primarily on the histopathology of the disease—that is, biomarkers that are linked to neurofibrillary tangles and amyloid plaques. This proposal is designed to expand this focus to develop biomarkers of the ‘cell biology’ of AD. Such biomarkers could potentially accelerate drug discovery, as therapeutic interventions are currently being developed that target endosomal trafficking defects in AD. Genetic and cell biology studies have previously linked the endosomal trafficking assembly Retromer to AD pathology. Most notable are deficiencies and rare mutations in retromer’s core protein, VPS35, and retromer’s receptor, SORL1. Depletion of either VPS35 or SORL1 mimics the core cytopathology in AD, enlarged endosomes in neurons, with concomitant mis-trafficking of endosomal cargoes. In an effort to characterize defects in the endocytic pathway resulting from retromer dysfunction, we recently completed a proteomic screen of CSF of VPS35 knock-out (KO) mice and control littermates. Among the proteins found elevated in the CSF of VPS35 KO mice were well established β-secretase BACE1 substrates, includingAPP (Amyloid Precursor Protein); APLP1/2 (Amyloid Beta Precursor Like Proteins 1 and 2); and CHL1 (Neuralcell adhesion molecule L1-like protein). Two of these proteins --APLP1 and CHL1-- were further validated inmouse CSF, and human CSF from cognitively healthy participants and prodromal AD patients. Collectively, our studies suggest BACE1 substrates as potential biomarkers of retromer-dependent endosomal dysfunction. However, since VPS35 is implicated in other neurodegenerative disorders, including Parkinson’s disease (PD), these new biomarkers may not be specific to AD. Therefore, relying on these exciting findings, but moving towards the development of a panel of biomarkers reflecting endosomal trafficking defects that are specific to AD, we will examine SORL1 mouse models and human pluripotent stem cell (hPSC) SORL1-derived neurons as a new source of biomarkers of endosomal trafficking. We will also investigate exosomes as an additional source of biomarkers of endosomal defects. Lastly, since Sorl1 protein levels are altered in AD and CSF from AD patients, we will examine SORL1 CSF levels as a potential biomarker for AD. Completion of this study will provide evidence that SORL1-dependent endosomal trafficking is a new source of biomarkers for AD. Moreover, we predict that the extensive studies here proposed will identify a unique and specific endosomal biomarker of the “cell biology” of AD.

内体功能障碍是阿尔茨海默病(AD)的一个公认的细胞生物学特征。然而， 反映内体交通缺陷的生物标志物仍然缺乏。电流成像和脑脊液(CSF) AD生物标记物主要关注疾病的组织病理学--即与 神经纤维缠结和淀粉样斑块。这项建议旨在扩大这一重点，以开发 阿尔茨海默病细胞生物学的生物标志物。这样的生物标记物可能会加速药物发现，因为 目前正在开发针对阿尔茨海默病内体转运缺陷的治疗干预措施。 遗传学和细胞生物学研究此前已将内体转运组装逆转录单体与 公元病理学。最值得注意的是逆转录病毒核心蛋白VPS35的缺陷和罕见的突变 逆转录病毒受体SORL1。VPS35或SORL1的耗尽与AD的核心细胞病理学相似，放大 神经元中的内体，伴随着内体货物的错误运输。 为了确定逆转录功能障碍引起的内吞途径缺陷的特征，我们最近 完成了VPS35基因敲除(KO)小鼠和对照仔鼠脑脊液蛋白质组的筛选。在VPS35KO小鼠脑脊液中发现的升高的蛋白质中有成熟的β分泌酶BACE1底物，包括APP(淀粉样前体蛋白)、APLP1/2(淀粉样β前体蛋白1和2)和CHL1(神经细胞黏附分子L1样蛋白)。其中两种蛋白质--APLP1和CHL1--在小鼠脑脊液和人类脑脊液中得到了进一步的验证。总而言之，我们的研究表明BACE1底物是逆转录依赖的内小体功能障碍的潜在生物标志物。 然而，由于VPS35与包括帕金森氏病(PD)在内的其他神经退行性疾病有关， 这些新的生物标志物可能不是AD特有的。因此，依靠这些令人兴奋的发现，但令人感动的是 开发一组反映内体转运缺陷的生物标志物，这些缺陷是特异性的 AD，我们将研究SORL1小鼠模型和人类多能干细胞(HPSC)SORL1来源的神经元 作为内体运输生物标记物的新来源。我们还将研究外切体作为额外的 内体缺陷的生物标志物的来源。最后，由于阿尔茨海默病和脑脊液中SORL1蛋白水平从 对于AD患者，我们将检测SORL1脑脊液水平作为潜在的AD生物标志物。这项研究的完成将 提供证据，证明依赖SORL1的内体运输是AD生物标记物的新来源。 此外，我们预测，这里提出的广泛研究将确定一个独特和具体的 阿尔茨海默病“细胞生物学”的内体生物标志物。