Molecular mechanism of senile cardiac amyloidosis

老年心脏淀粉样变的分子机制

基本信息

批准号：
8126404
负责人：
Lawreen H. Connors
金额：
$ 31.7万
依托单位：
BOSTON UNIVERSITY MEDICAL CAMPUS
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-09-01 至 2014-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8126404
关键词：
Age Aged, 80 and over American Amyloid Amyloid Fibrils Amyloidosis Autopsy Binding Biochemical Biological Assay Biological Markers Blood Brain natriuretic peptide Caliber Cardiac Cardiac Myocytes Cardiomyopathies Cardiovascular Diseases Cell physiology Clinical Data Complex Congo Red Control Groups Coupled Crystallins Data Deposition Diagnostic Diagnostic Procedure Disease Progression Echocardiography Elderly Elderly man Electrophoresis Etiology Extracellular Space Fatty acid glycerol esters Health Heart Heart Diseases Heart failure High Pressure Liquid Chromatography Immunoblotting In Vitro Individual Left Left Ventricular Ejection Fraction Left Ventricular Remodeling Life Link Mass Spectrum Analysis Measures Mediating Molecular Molecular Chaperones Molecular Weight Morbidity - disease rate Myocardial Pathology Patients Plasma Proteins Population Prealbumin Proteins Proteome Proteomics Recombinant Proteins Relative (related person)Sampling Sedimentation process Serum Serum Proteins Specimen Stress Structure Testing Therapeutic Therapeutic Intervention Thick Thioflavin T Tissue Sample Tissues Troponin I Two-Dimensional Gel Electrophoresis Ventricular aging population amyloid formation analytical ultracentrifugation base design disease diagnosis extracellular fibrillogenesis follow-up insight light scattering multidisciplinary novel sulfated glycoprotein 2

项目摘要

DESCRIPTION (provided by applicant): Cardiomyopathy in elderly men can be the result of extracellular deposits of amyloid in the heart, pathology referred to as Senile Systemic (or Cardiac) Amyloidosis (SSA). In SSA, wild-type transthyretin (TTR), normally a serum protein, forms amyloid deposits which disrupt normal cardiac cell functioning. The molecular mechanisms in SSA remain undefined, but are important to determine as autopsy studies have suggested that heart failure caused by amyloidosis may be vastly unrecognized and undiagnosed in the ever expanding aging population. Based on our previous studies, we hypothesize that in SSA: (1) soluble, prefibrillar high molecular weight forms of TTR (TTRHMW) are present in serum and develop into amyloid fibrils by a mechanism mediated by chaperone proteins (possibly 1B-crystallin and/or clusterin), (2) TTRHMW are formed through interactions of TTR with biomolecules whose concentration, structure or function are specific to the serum and/or cardiac tissue of patients with SSA, and (3) the presence of TTRHMW in SSA sera is associated with more rapid cardiac disease progression. Utilizing a proteomic approach coupled to an analytical strategy which is multidisciplinary (biochemical, biophysical, histopathologic, and cardiologic), we hope to elucidate the molecular mechanisms underlying SSA, and in so doing, provide useful diagnostic information and identify novel targets for therapeutic intervention. To test our hypothesis, we propose: Specific Aim 1: To investigate TTR molecular associations in SSA by examining patient sera for the presence of TTRHMW using sedimentation rate analysis and characterizing purified TTRHMW by mass spectrometric (MS) analyses. Specific Aim 2: To link proteomic changes, TTRHMW, and amyloid formation in SSA by defining serum and cardiac (or fat) tissue proteomes in patients using 2-D gel electrophoresis and MS initially focusing on 1B- crystallin and clusterin. The amyloidogenic potential of TTRHMW and the effects of 1B-crystallin and clusterin (and other associated biomolecules identified in Aim 1) on fibril formation will be tested using an established in vitro amyloid fibrillogenesis assay and recombinant proteins. Specific Aim 3: To study the association of TTRHMW with more rapid disease progression in SSA by measuring TTRHMW in patient sera at baseline and annually for 3 years and correlating results with cardiac troponin I, brain natriuretic peptide, left ventricular (LV) end-diastolic and end-systolic diameters, and LV ejection fraction as measures of ongoing myocardial damage and cardiac structural remodeling. PUBLIC HEALTH RELEVANCE: Heart disease associated with amyloid deposits is a life threatening condition and may be a significant cause of morbidity in the aging population. It is expected that as many as 2.25 million Americans (25% of the US population over the age of 80) are afflicted with senile systemic amyloidosis (SSA), pathology of unknown etiology related to the amyloidotic aggregation of the plasma protein transthyretin (TTR). The studies proposed in this application will help us to elucidate the molecular mechanisms underlying SSA, and in so doing, provide the theoretical platform for the design of effective and non-invasive diagnostic procedures and therapeutic strategies.

描述（由申请人提供）：老年男性的心肌病可能是淀粉样蛋白在心脏细胞外沉积的结果，病理学称为老年全身性（或心脏）淀粉样变性（SSA）。在 SSA 中，野生型转甲状腺素蛋白 (TTR)（通常是一种血清蛋白）会形成淀粉样沉积物，破坏正常的心脏细胞功能。 SSA 的分子机制仍未明确，但确定这一机制很重要，因为尸检研究表明，在不断扩大的老龄化人口中，淀粉样变性引起的心力衰竭可能很大程度上未被识别和诊断。根据我们之前的研究，我们假设在 SSA 中：(1) 可溶性前纤维高分子量形式的 TTR (TTRHMW) 存在于血清中，并通过伴侣蛋白（可能是 1B-晶状体蛋白和/或 1B-晶状体蛋白）介导的机制发育成淀粉样原纤维。或凝聚素），（2）TTRHMW是通过TTR与生物分子相互作用形成的，其浓度、结构或功能对血清和/或心脏组织具有特异性(3) SSA 血清中 TTRHMW 的存在与更快的心脏病进展相关。利用蛋白质组学方法与多学科（生物化学、生物物理、组织病理学和心脏病学）分析策略相结合，我们希望阐明 SSA 的分子机制，从而提供有用的诊断信息并确定治疗干预的新靶点。为了检验我们的假设，我们提出：具体目标 1：通过使用沉降率分析检查患者血清中是否存在 TTRHMW 并通过质谱 (MS) 分析表征纯化的 TTRHMW，研究 SSA 中的 TTR 分子关联。具体目标 2：通过使用 2-D 凝胶电泳和 MS 定义患者的血清和心脏（或脂肪）组织蛋白质组，将 SSA 中的蛋白质组变化、TTRHMW 和淀粉样蛋白形成联系起来，最初关注 1B- 晶状体蛋白和凝聚蛋白。 TTRHMW 的淀粉样蛋白生成潜力以及 1B-晶状体蛋白和簇蛋白（以及目标 1 中鉴定的其他相关生物分子）对原纤维形成的影响将使用已建立的体外淀粉样原纤维生成测定和重组蛋白进行测试。具体目标 3：通过在基线和每年 3 年内测量患者血清中的 TTRHMW，并将结果与心肌肌钙蛋白 I、脑钠尿肽、左心室 (LV) 舒张末期相关联，研究 TTRHMW 与 SSA 疾病进展更快的关联收缩末期直径和左心室射血分数作为持续心肌损伤和心脏结构重塑的指标。公众健康相关性：与淀粉样蛋白沉积相关的心脏病是一种危及生命的疾病，并且可能是老年人口发病的一个重要原因。预计有多达 225 万美国人（占美国 80 岁以上人口的 25%）患有老年系统性淀粉样变性 (SSA)，这种病因不明的病理学与血浆蛋白转甲状腺素蛋白 (TTR) 的淀粉样聚集有关。本申请中提出的研究将帮助我们阐明 SSA 的分子机制，从而为设计有效和非侵入性的诊断程序和治疗策略提供理论平台。