Functional assessment of pathological α-syn and Aβ species in LBD

LBD 中病理 α-syn 和 Aβ 物种的功能评估

• 批准号: 10686906
• 负责人: Pamela J McLean
• 金额: $ 57.57万
• 依托单位: MAYO CLINIC JACKSONVILLE
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-20 至 2025-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10686906
• 关键词: Alleles; Alzheimer' s Disease; Amyloid beta-Protein; Autophagocytosis; Autopsy; Biochemical; Biological; Biological Assay; Brain; Brain region; Cell model; Cells; Characteristics; Clinical; Cognitive deficits; Collaborations; Complement; Complex; Dementia; Dementia with Lewy Bodies; Development; Diagnostic; Disease; Endosomes; Enzymes; Genetic; Genetic Risk; Genetic Variation; Health; Human; Immunoassay; Impairment; Individual; Induced pluripotent stem cell derived neurons; Knowledge; Lewy Bodies; Lewy Body Dementia; Lipids; Lysosomes; Measures; Membrane; Methods; Molecular Conformation; Mutation; Neurons; Parkinson Disease; Parkinson' s Dementia; Pathologic; Pathway interactions; Patients; Positioning Attribute; Process; Proteins; Proteomics; Reporter; Research Personnel; Scanning; Senile Plaques; Slide; Structure; Subcellular Fractions; System; Tissues; Toxic effect; Validation; abeta accumulation; alpha synuclein; arm; beta pleated sheet; brain tissue; dementia risk; genetic risk factor; glucosylceramidase; in vivo; lipidomics; motor deficit; motor symptom; neuropathology; neurotoxic; novel; phosphoneuroprotein 14; prion-like; protein structure; response; single molecule; structural determinants; superresolution microscopy; synergism; transcriptomics

ABSTRACT Elucidation of underlying disease mechanisms in Lewy body dementia requires the systematic characterization of disease-specific changes in LBD brain tissue. The combination of dementia and motor symptoms at the clinical level is reflected in the neuropathology by the accumulation of alpha-synuclein (α-syn) in Lewy bodies and beta-amyloid (Aβ) in amyloid plaques. Both Aβ and α-syn are capable of aggregating into oligomers, fibrils, and beta sheets, but the aggregates that form are extremely heterogeneous in terms of both structure and function. The identification of which specific subspecies of the proteins are neurotoxic or support aggregation is poorly understood and as a result development of diagnostics and treatments that depend on knowledge of protein structure has been slow. Recent studies have suggested a ”seeded” or “prion-like” propagation for both α-syn and Aβ, indicating that abnormal conformations may ‘spread’ from diseased to healthy cells. While synthetic seeds of α-syn and Aβ confer toxicity in cells through various mechanisms, it is well known that the exact method of preparing these species influences their bioactivity to a high degree. Herein we take the next important step to analyze the actual subspecies from post-mortem brains, to define and compare aggregates, and identify mechanisms of toxicity and spreading underlying the selective regional vulnerabilities. We will extract soluble and insoluble α-syn and Aβ species from neuropathologically confirmed LBD brains with or without genetic LBD risk factors for structural and functional characterization. We will assess load and distribution of α-syn and Aβ subspecies and will detail their characteristics including size, structure and self- templating capabilities (Aim 1). The critical involvement of autophagy-lysosomal pathways in LBD is emphasized by the underlying genetic risks for LBD. Besides mutations in glucocerebrosidase (GBA) that interfere with lysosomal functions, it is well established that individuals with the APOE ϵ4 allele have a 6-fold greater risk for DLB. We will assess alterations in lysosome function in LBD brain and determine their response and contribution to processing, aggregation, and toxicity of α-syn and Aβ subspecies (Aim 2). We will use patients’ iPSC-derived neurons with different genetic risk factors to functionally validate the contribution to aggregation, toxicity and spreading of α-syn and Aβ (Aim 3). The expertise of this group of investigators synergizes to identify differences in structure and function of subspecies, to investigate mechanisms of aggregation and toxicity, and to unravel the contributions of the genetic variations and alterations in selective autophagy pathways to regional vulnerabilities. This puts us in a unique position to complement the studies of Projects 1, 2, and 3 of this CWOW at multiple levels and towards the full characterization of α-syn and Aβ subspecies.

摘要 要阐明路易体痴呆的潜在疾病机制，需要系统的描述 LBD脑组织的疾病特异性变化。痴呆症和运动症状的结合 临床水平通过路易小体中α-突触核蛋白(α-SYN)的积聚反映在神经病理学中 和淀粉样斑块中的β-淀粉样蛋白(Aβ)。Aβ和α-SYN都能够聚集成低聚物，纤维， 和β-折叠，但形成的聚集体在结构和结构方面都非常不均匀 功能。确定哪些特定的蛋白质亚种具有神经毒性或支持聚集 知之甚少，其结果是诊断和治疗的发展依赖于 蛋白质结构一直很缓慢。最近的研究表明，这两种病毒的繁殖方式都是“播种”或“类普里恩”。 α-SYN和Aβ，表明异常构象可能从患病细胞‘扩散’到健康细胞。而当 α-SYN和A-β的合成种子通过不同的机制赋予细胞毒性，众所周知， 制备这些物种的准确方法在很大程度上影响它们的生物活性。在这里我们要做下一件事 重要的一步是分析死后大脑中的实际亚种，定义和比较聚集体， 并确定有选择性的区域脆弱性背后的毒性和传播机制。我们会 从神经病理证实的腰椎间盘突出症患者脑组织中提取可溶性和不溶性α-SYN和A-β 没有遗传性LBD危险因素的结构和功能表征。我们将评估负载和 α-SYN和Aβ亚种的分布，并将详细介绍他们的特征，包括大小，结构和自我 模板能力(目标1)。自噬-溶酶体通路在LBD中的关键参与是 强调了LBD的潜在遗传风险。除了葡萄糖脑苷酶(GBA)突变外， 干扰溶酶体功能，众所周知，携带载脂蛋白Eϵ4等位基因的个体有6倍于 德意志银行面临更大的风险。我们将评估LBD脑中溶酶体功能的变化并确定它们的反应 以及对α-SYN和Aβ亚种的加工、聚集和毒性的贡献(目标2)。我们将使用 不同遗传危险因素对患者IPSC来源神经元功能的影响 α-SYN和Aβ的聚集、毒性和传播(目标3)。这组调查人员的专业知识 协同作用以识别亚种在结构和功能上的差异，以研究 聚集和毒性，并揭示选择的遗传变异和改变的贡献 地区性脆弱性的自噬途径。这使我们处于一个独特的地位，可以补充对 本CW的项目1、2和3在多个层面上，并朝着全面描述α-SYN和Aβ的方向发展 亚种。