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: 10478195
• 负责人: Pamela J McLean
• 金额: $ 57.56万
• 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 2024-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10478195
• 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; 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; Microscopy; Molecular Conformation; Mutation; Neurons; Parkinson Disease; Parkinson' s Dementia; Pathologic; Pathway interactions; Patients; Positioning Attribute; Process; Proteins; Proteomics; Reporter; Research Personnel; Resolution; Scanning; Seeds; Senile Plaques; Slide; Structure; Subcellular Fractions; System; Tissues; Toxic effect; Validation; alpha synuclein; arm; beta pleated sheet; brain tissue; dementia risk; genetic risk factor; glucosylceramidase; in vivo; lipidomics; motor deficit; motor symptom; neuropathology; neurotoxic; novel; prion-like; protein structure; response; single molecule; 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.

抽象的 阐明路易斯体内痴呆中潜在疾病机制需要系统的特征 LBD脑组织中疾病特异性的变化。痴呆症和运动症状在 临床水平反映在神经病理学中，通过α-核蛋白（α-Syn）在路易体体内的积累 淀粉样蛋白斑中的β-淀粉样蛋白（Aβ）。 Aβ和α-Syn都能够汇总成寡聚，原纤维， 和beta板，但是在结构和 功能。蛋白质的特定亚种的鉴定是神经毒性或支持聚集的 依赖于知识 蛋白质结构一直很慢。最近的研究表明，两者都表明“种子”或“ prion样”传播 α-syn和Aβ，表明异常构象可能会从解散到健康细胞中“扩散”。尽管 α-Syn和Aβ的合成种子通过各种机制赋予细胞中的毒性，众所周知 制备这些物种的确切方法在高度上影响其生物活性。在这里，我们采取下一个 分析从验尸大脑的实际亚种，定义和比较聚集体的重要步骤 并确定毒性机制并扩散选择性区域脆弱性的基础。我们将 从神经病因确认的LBD大脑中提取固体和不溶性α-Syn和Aβ物种 没有结构和功能表征的遗传LBD风险因素。我们将评估负载和 α-Syn和Aβ亚种的分布，并将详细说明其特征，包括大小，结构和自我 模板功能（AIM 1）。自噬 - 溶糖途径在LBD中的关键参与是 由LBD的潜在遗传风险强调。除了在葡萄糖脑培合酶（GBA）中的突变外 干扰溶酶体功能，众所周知，APOE ϵ4等位基因的个体具有6倍 DLB的风险更大。我们将评估LBD脑中溶酶体功能的变化并确定其反应 以及对α-Syn和Aβ亚种的加工，聚集和毒性的贡献（AIM 2）。我们将使用 患者的IPSC衍生神经元具有不同的遗传危险因素，以便在功能上验证对 α-Syn和Aβ的聚集，毒性和扩散（AIM 3）。这组调查人员的专业知识 协同结合以确定亚种结构和功能的差异，以研究 聚集和毒性，并揭示遗传变异和选择性改变的贡献 自噬通向区域脆弱性的途径。这使我们处于独特的位置，以完成研究 该杂种的项目1、2和3在多个级别上，朝着α-Syn和Aβ的全部表征 亚种。