Understanding the Mechanism of Pathological alpha-Synuclein Transmission

了解病理性 α-突触核蛋白传播的机制

• 批准号: 10647710
• 负责人: Xiaobo Mao
• 金额: $ 40.94万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-17 至 2024-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10647710
• 关键词: Alpha-Synuclein transgenic mouse; Amyloid beta-Protein; Antibodies; Binding; Biotin; Cells; Cessation of life; Complement; Complex; Data; Dementia with Lewy Bodies; Evaluation; Gene Activation; Human; In Vitro; Integral Membrane Protein; Knock-out; Knowledge; Lymphocyte Activation; Mediating; Mediator; Methods; Modeling; Molecular; Multiple System Atrophy; Mus; Mutate; Nerve Degeneration; Neurodegenerative Disorders; Neuroglia; Neurons; Outcome; Parkinson Disease; Pathogenesis; Pathologic; Proteins; Role; Therapeutic Agents; aged; alpha synuclein; experimental study; in vivo; insight; mouse model; neuropathology; neurotoxicity; novel; overexpression; pre-formed fibril; receptor; screening; synucleinopathy; transmission process

α-Synucleinopathies are a subset of neurodegenerative diseases, including Parkinson's disease (PD), dementia with Lewy Bodies (DLB) and multiple system atrophy (MSA) (1), which are characterized by abnormal accumulation of misfolded α-synuclein (α-syn) protein in neurons or glial cells. Emerging evidence suggests that the cell-to-cell transmission of pathological α-syn substantially cause neurodegeneration. However, the molecular mechanism of α-syn transmission is poorly understood. We have identified three transmembrane proteins that strongly bind with α-syn PFF: (i) lymphocyte activation gene-3 (LAG3), (ii) amyloid β precursor-like protein 1 (APLP1), and (iii) neurexin 1-β. LAG3 is an essential receptor, mediating internalization of α-syn PFF; however, substantial α-syn PFF binds to LAG3-/- (knockout) neurons, suggesting that a unidentified candidate(s) (e.g. APLP1) binds with pathologic α-syn, and facilitate the internalization. In this proposal, we hypothesize: (i) APLP1 is an essential receptor, that mediates α-syn transmission; (ii) APLP1-LAG3 complex synergistically mediates α-syn transmission; (iii) depletion of APLP1, LAG3, or APLP1- LAG3 complex, can reduce α-syn-induced neurodegeneration of α-syn transgenic mice. Accordingly, experiments are proposed to characterize the roles of APLP1, LAG3 and the AL complex in mediating the pathogenesis of α-synucleinopathies, in cell-to-cell transmission models and the α-syn transgenic mouse model. Experiments in two mice models with α-synucleinopathies, will be complemented by studies in cells and cell-free experiments, thus allowing the deciphering of each spreading step in the interaction of APLP1, LAG3, or the AL complex with pathologic α-syn. The successful completion of these studies will greatly enhance our understanding of the molecular mechanisms of α-syn cell-to-cell transmission via receptors, by: (i) identifying APLP1 as a novel receptor that mediates α-syn spreading, (ii) understanding the synergistic effect of the AL complex on mediating binding and internalization of α-syn PFF, (iii) providing essential preliminary evaluation of anti-LAG3 antibody as a potential therapeutic agent against PD and related α-synucleinopathies, and (iv) understanding the roles of APLP1, LAG3, and the AL complex in mediating neurodegeneration of α-syn transgenic mice.

α-突触核蛋白病是神经退行性疾病的一个子集，包括帕金森病 (PD)、 路易体痴呆 (DLB) 和多系统萎缩 (MSA) (1)，其特征是 错误折叠的 α-突触核蛋白 (α-syn) 蛋白在神经元或神经胶质细胞中异常积累。 表明病理性 α-syn 的细胞间传递实质上导致神经变性。 然而，我们对 α-syn 传递的分子机制知之甚少。 与 α-syn PFF 强烈结合的跨膜蛋白：(i) 淋巴细胞激活基因 3 (LAG3)，(ii) 淀粉样蛋白 β 前体样蛋白 1 (APLP1) 和 (iii) 神经毒素 1-β 是介导的重要受体。 α-syn PFF 的内化；然而，大量 α-syn PFF 与 LAG3-/-（敲除）神经元结合，表明 未识别的候选者（例如 APLP1）与病理性 α-syn 结合，并促进内化。 在该提案中，我们追求：(i) APLP1 是介导 α-syn 传递的重要受体；(ii) APLP1-LAG3 复合物协同介导 α-syn 传递；(iii) APLP1、LAG3 或 APLP1- 的消耗； LAG3复合物可以减少α-syn诱导的α-syn转基因小鼠的神经变性。 实验旨在表征 APLP1、LAG3 和 AL 复合物在介导 细胞间传播模型和 α-syn 转基因中 α-突触核蛋白病的发病机制 小鼠模型。在两种患有 α-突触核蛋白病的小鼠模型中进行的实验将得到以下研究的补充。 细胞和无细胞实验，从而可以破译相互作用中的每个传播步骤 APLP1、LAG3 或 AL 复合物与病理性 α-syn 的成功完成将有助于实现这些研究。 极大地增强了我们对α-syn细胞间传递分子机制的理解 受体，通过：(i) 将 APLP1 识别为介导 α-syn 传播的新型受体，(ii) 了解 AL 复合物对介导 α-syn PFF 的结合和内化的协同作用，(iii) 提供 抗 LAG3 抗体作为 PD 及相关疾病潜在治疗剂的必要初步评估 α-突触核蛋白病，以及 (iv) 了解 APLP1、LAG3 和 AL 复合物在介导中的作用 α-syn 转基因小鼠的神经变性。