Mechanisms of synaptic dysfunction in Parkinson's and other synuclein-linked dise

帕金森病和其他突触核蛋白相关疾病中突触功能障碍的机制

• 批准号: 8571603
• 负责人: Jennifer Rebecca Morgan
• 金额: $ 24.33万
• 依托单位: MARINE BIOLOGICAL LABORATORY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-01-15 至 2016-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8571603
• 关键词: Functional disorder; Link; Parkinson Disease; Synapses; synuclein

DESCRIPTION (provided by applicant): The long term goal of this project is to identify the cellular and molecular mechanisms that give rise to the synaptic defects in patients with Parkinson's disease (PD) and other related neurological disorders. The pathological hallmark of these diseases includes abnormal levels of ¿-synuclein at synapses and throughout the neuron. While it is generally agreed that synucleins participate in synaptic vesicle trafficking, the exact steps of the vesicle trafficking pathway that are perturbed by altered levels of synuclein remain unclear. Thus, at present, it is not possible to design targeted strategies for improving synaptic function in PD. Experiments proposed here take the first steps toward this by identifying the precise synaptic vesicle trafficking defects caused excess synuclein at synapses, the mechanisms giving rise to these defects, and new strategies for reversing them. The experiments take advantage of two model synapses that are ideally suited for studies of synaptic vesicle trafficking, using both acute and genetic perturbations. The combination of highly quantitative biochemical assays to measure synuclein interactions, design of reagents to perturb these interactions, and detailed ultrastructural analyses provides the best opportunity to identify the cellular and molecular mechanisms leading to synuclein-induced synaptic vesicle trafficking defects. In initial studies, excess wild type synuclein causes a loss of synaptic vesicles, increased cisternae, and altered clathrin-coated profiles, consistent with inhibiting clathrin-mediated synaptic vesicle recycling. Going forward, proposed experiments are aimed at identifying the cellular mechanisms by which excess wild type ¿-synuclein and PD-related mutations (e.g. A30P, E46K, A53T) cause vesicle trafficking defects (Aims 1 and 2). Experiments will also investigate how synuclein interactions with specific synaptic binding partners (e.g. PI(4,5)P2 and the uncoating ATPase) contribute to the synaptic vesicle trafficking defects, and targeted strategies for disrupting these interactions will be assessed as a possible means for reversing synaptic defects (Aim 2 and 3). The proposed experiments are innovative because they are the first to use a combination of quantitative biochemical binding assays, acute perturbations, controlled stimulation conditions, and detailed ultrastructural analyses to identify the precise synaptic vesicle trafficking defects caused by excess synuclein or its mutations, which is ideally suited for the overall goal. The experiments are significant because they represent the first steps toward understanding the mechanisms giving rise to the synaptic defects, and they provide possible targeted, molecular strategies for improving synaptic function. Thus, these studies have direct implications for slowing or halting the neurodegeneration, cognitive deficits, and dementia in PD and other synucleinopathies.

描述（由申请人提供）：本项目的长期目标是确定帕金森病（PD）和其他相关神经系统疾病患者中引起突触缺陷的细胞和分子机制。这些疾病的病理标志包括突触和整个神经元中的突触核蛋白水平异常。虽然人们普遍认为突触核蛋白参与突触囊泡运输，但确切的 受突触核蛋白水平改变干扰的囊泡运输途径的步骤仍不清楚。因此，目前，它是不可能的设计有针对性的策略，以改善突触功能的PD。这里提出的实验采取了第一步，通过确定精确的突触囊泡运输缺陷引起的突触过量的突触核蛋白，引起这些缺陷的机制，以及逆转它们的新策略。实验利用两个模型突触，非常适合研究突触囊泡贩运，使用急性和遗传扰动。高度定量的生化分析，以测量突触核蛋白的相互作用，设计试剂干扰这些相互作用，和详细的超微结构分析的组合提供了最好的机会，以确定细胞和分子机制，导致突触核蛋白诱导的突触囊泡运输缺陷。在最初的研究中，过量的野生型突触核蛋白导致突触囊泡的损失，增加脑池，并改变网格蛋白包被的配置文件，与抑制网格蛋白介导的突触囊泡回收一致。展望未来，提出的实验旨在鉴定过量野生型突触核蛋白和PD相关突变（例如A30P、E46K、A53T）引起囊泡运输缺陷的细胞机制（目的1和2）。实验还将研究突触核蛋白与特定突触结合配偶体（例如PI（4，5）P2和未包被的ATP酶）的相互作用如何促成突触囊泡运输缺陷，并且将评估用于破坏这些相互作用的靶向策略作为逆转突触缺陷的可能手段（目的2和3）。所提出的实验是创新的，因为它们是第一个使用定量生化结合测定，急性扰动，受控刺激条件和详细的超微结构分析的组合，以确定由过量突触核蛋白或其突变引起的精确的突触囊泡运输缺陷，这非常适合于总体目标。这些实验是重要的，因为它们代表了理解引起突触缺陷的机制的第一步，并且它们为改善突触功能提供了可能的靶向分子策略。因此，这些研究对于减缓或停止PD和其他突触核蛋白病中的神经变性、认知缺陷和痴呆具有直接意义。