Clusterin glycosylation as diagnostic and prognostic biomarker for Alzheimer's disease

簇蛋白糖基化作为阿尔茨海默病的诊断和预后生物标志物

• 批准号: 10699168
• 负责人: DOBRIN NEDELKOV
• 金额: $ 38.48万
• 依托单位: ISOFORMIX, INC.
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-06-15 至 2025-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10699168
• 关键词: Abeta clearance; Abeta synthesis; Alzheimer' s Disease; Alzheimer' s disease brain; Alzheimer' s disease pathology; Alzheimer' s disease risk; Alzheimer' s disease therapeutic; Alzheimer’s disease biomarker; Amyloid Fibrils; Amyloid beta-42; Amyloid beta-Protein; Amyloid beta-Protein Precursor; Antibodies; Apolipoprotein E; Area; Attention; Binding; Biological Assay; Biological Markers; Blinded; Blood - brain barrier anatomy; Brain; Clinical; Data; Deposition; Detection; Development; Diagnosis; Disaccharides; Enzymes; Excision; Future; Genotype; Hippocampus; Immunoassay; Impairment; Individual; Late Onset Alzheimer Disease; Link; MALDI-TOF Mass Spectrometry; Mass Spectrum Analysis; Measures; Molecular Chaperones; Neuraminidase; Pathogenesis; Pathway interactions; Pattern; Performance; Phase; Phenotype; Plasma; Play; Polysaccharides; Prognostic Marker; Protein Isoforms; Reproducibility; Research; Risk; Role; Sampling; Senile Plaques; Severities; Sialic Acids; Specificity; Structure; Technology; Testing; Therapeutic; Up-Regulation; Validation; Variant; Western Blotting; apolipoprotein E-3; apolipoprotein E-4; cohort; commercialization; cost effective; cost efficient; detection assay; diagnostic biomarker; diagnostic value; extracellular; genetic risk factor; genome wide association study; glycosylation; neuroprotection; novel; prevent; prognostic value; sugar; sulfated glycoprotein 2; tau Proteins; therapeutic development; trend; β-amyloid burden

PROJECT SUMMARY Clusterin is the third most predominant genetic risk factor for late onset Alzheimer’s disease (AD). Clusterin facilitates the transport of soluble amyloid-b (Ab) across the blood-brain barrier. Clusterin binds soluble forms of Ab, preventing their aggregation into amyloid fibrils. However, there is no clear correlation between plasma or CSF clusterin concentration levels and AD, even though there is substantial evidence for upregulation of clusterin in the AD brain and colocalization with Ab plaques. Clusterin is heavily glycosylated, with ~25% of its mass comprised of N-linked glycans. Glycosylation of clusterin is spatially and temporally regulated, and it is important for its function as an extracellular chaperone. Glycosylation of clusterin may play an important role in the interaction with Ab and its clearance. In this Phase I project we propose to develop, optimize and validate a fast and cost-efficient mass spectrometry (MS)-immunoassay for detection of clusterin glycoforms that reveals both intact glycosylated clusterin and its component glycan structures. We will first optimize assay parameters such as antibody amount, sample volumes and dilutions, post-capture rinses, enzymatic release of sialic acids and the full glycans with sialidase and PNGaseF enzymes, and MS acquisition parameters. The assay performance will be validated by testing its robustness, accuracy, specificity, and reproducibility. We will use the assay on a cohort of matched CSF and plasma samples (n=106) from mildly impaired and healthy individuals at risk of AD. Data in the form of intact clusterin mass peaks shifts between plasma and CSF, mass shifts within samples following sialidase and PNGaseF treatment, the relative ratios of clusterin glycoforms, and IDs and ratios of the released glycans, will be compared across the cohort, and correlations with apoE genotype, apoE isoform-specific glycosylation, Aβ42, Tau and pTau will be examined. The findings from the first cohort will be validated with a second cohort (n=100). Our value proposition is a fast and cost-effective assay for analyzing clusterin glycoforms and glycans that could be utilized for evaluating the role of clusterin glycosylation in AD pathogenesis. Clusterin glycosylation could serve as a biomarker for assessing AD risk, or as a target for the development of therapeutics that modify its glycosylation.

项目摘要 簇蛋白是晚期发作阿尔茨海默氏病（AD）的第三大主要遗传危险因素。簇蛋白 促进固体淀粉样蛋白-B（AB）在血脑屏障中的运输。簇蛋白结合固体形式的 AB，防止其聚集成淀粉样蛋白原纤维。但是，等离子体或 CSF簇素浓度水平和AD，即使有大量证据表明簇蛋白上调 在AD大脑中，与AB斑块共定位。簇蛋白是大量糖基化的，其质量约为25％ 完成N连接的聚糖。簇蛋白的糖基化在空间和临时调节上是重要的，这很重要 因为它是细胞外伴侣的功能。簇蛋白的糖基化可能在 与AB及其清除率的互动。 在这个阶段I项目中，我们建议开发，优化和验证快速且成本效益的质谱法 （MS） - 用于检测簇蛋白糖型的免疫测定法，揭示了完整的糖基化簇蛋白及其IT 组件聚糖结构。我们将首先优化测定参数，例如抗体量，样品量 和稀释液，捕获后路线，唾液酸的酶促释放和带有唾液酸酶和的完整聚糖 PNGASEF酶和MS采集参数。测定性能将通过测试其 鲁棒性，准确性，特异性和可重复性。我们将在匹配的CSF组上使用该测定法 来自有AD风险的轻度受损和健康个体的血浆样品（n = 106）。完整形式的数据 簇蛋白质量峰在血浆和CSF之间移动，唾液酸酶后样品内的质量转移和 PNGASEF处理，簇糖素的相对比以及释放的聚糖的ID和比率将 在整个队列中进行比较，并与APOE基因型，APOE同工型特异性糖基化Aβ42， 将检查Tau和Ptau。 第一个队列的发现将通过第二个队列（n = 100）验证。 我们的价值提议是分析的簇糖型和聚糖的快速且具有成本效益的测定法 用于评估簇蛋白糖基化在AD发病机理中的作用。簇蛋白糖基化可能 用作评估AD风险的生物标志物，或作为开发修改其修改的治疗剂的目标 糖基化。