Investigating the Role of LRRK2 Hyperactivity in Autophagic and Synaptic Deficits

研究 LRRK2 过度活跃在自噬和突触缺陷中的作用

• 批准号: 10549286
• 负责人: Dan Dou
• 金额: $ 3.5万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10549286
• 关键词: Affect; Age; Aging; Autophagocytosis; Axon; Biogenesis; Clinical; Complement; Complex; Data; Dementia; Dependence; Development; Disease; Disease model; Environment; Foundations; Functional disorder; Future; Genetic; Goals; Homeostasis; Human; Hyperactivity; Idiopathic Parkinson Disease; Image; Impaired cognition; Impairment; Induced pluripotent stem cell derived neurons; LRRK2 gene; Label; Link; Lysosomes; Mentors; Mitochondria; Motor; Mutation; Nerve Degeneration; Neurodegenerative Disorders; Neurons; Organelles; PHluorin; Parkinson Disease; Pathogenesis; Pathogenicity; Pathologic; Pathway interactions; Patients; Peptide Hydrolases; Phospho-Specific Antibodies; Phosphorylation; Phosphotransferases; Physicians; Physiological; Play; Population; Prevalence; Process; Proteins; Regulation; Repression; Research; Rodent; Role; Scientist; Severities; Synapses; Synaptic Transmission; Synaptic Vesicles; Synaptophysin; Testing; Therapeutic; Training; Transmembrane Transport; Travel; Vesicle; Work; Writing; age related; burden of illness; causal variant; cognitive impairment in Parkinson' s; dominant genetic mutation; experimental study; fluorescence imaging; healthy aging; human disease; improved; in vivo; induced pluripotent stem cell; inhibitor; neuronal cell body; non-motor symptom; presynaptic; rab GTP-Binding Proteins; recruit; retrograde transport; therapeutically effective; vesicle transport; vesicular release

PROJECT SUMMARY Parkinson’s disease (PD) is the second-most prevalent neurodegenerative disease and the fastest- growing. PD increases in both prevalence and severity with age, and the disease burden is projected to dramatically increase in coming decades as the population ages. Current therapies do not address the underlying neurodegeneration, and development of improved therapeutics is hindered by poor understanding of the pathogenesis. Changes in homeostatic regulation of both autophagy and synaptic transmission have been implicated in not only PD but also physiological aging. Leucine-rich repeat kinase 2 (LRRK2) is a leading candidate for a nexus bridging autophagy and PD pathogenesis. Mutations in LRRK2 are the most common genetic cause of PD, and increased LRRK2 kinase activity has also been linked to idiopathic PD. There is accumulating evidence that multiple PD-causative pathways may converge on disrupting autophagy through mechanisms dependent on LRRK2 activity. Recently, LRRK2 was shown to phosphorylate a subset of Rab GTPases, providing an important opportunity to make advances in the understanding of mechanisms downstream of LRRK2. The goal of this proposal is to elucidate the role that LRRK2 may play in autophagy and synaptic homeostasis, in the context of pathogenic mutations associated with PD. Our preliminary data suggests that the most common pathogenic mutation in LRRK2, p.G2019S, disrupts autophagic vesicle (AV) transport in the axons of rodent and iPSC-derived human neurons. We hypothesize that multiple pathogenic PD mutations disrupt autophagy and synaptic vesicle precursor (SVP) transport through mechanisms dependent on increased LRRK2 kinase activity. To test this hypothesis, we will exploit iPSC-derived neurons as a human disease model. Experiments proposed in Aim 1a will explore whether LRRK2-p.G2019S causes deficits in AV cargo degradation, as a potential mechanism of neurodegeneration. In Aim 1b, we will determine whether the VPS35-p.D620N mutation, a different pathogenic PD mutation that increases LRRK2 activity, causes similar autophagy deficits as LRRK2-p.G2019S. Finally, in Aim 2, we will explore whether SVP transport from the soma to the axon is impaired by mutations causing LRRK2 hyperactivity, with potential ramifications for synaptic homeostasis. Collectively, we expect that these Aims will help elucidate mechanisms by which multiple causes of PD can converge on a LRRK2-dependent pathway to disrupt neuronal autophagy and synaptic homeostasis. Additionally, this work may provide a foundation for future work to shed light on pathways by which physiological aging alters these processes in the absence of diseases of aging. To complement this research plan, a comprehensive training plan will help the trainee meet specific Research Goals, Professional Goals (including writing, mentoring, and presentation), and Clinical Goals (tying together an integrated physician-scientist training pathway), all in a supportive, collaborative scientific environment.

项目总结 帕金森病(PD)是第二大最常见的神经退行性疾病，也是最快的- 不断增长。随着年龄的增长，帕金森病的患病率和严重性都会增加，预计疾病负担将 在接下来的几十年里，随着人口老龄化，这一数字将急剧增加。目前的治疗方法并没有解决 潜在的神经退行性变和改进的治疗方法的发展因缺乏理解而受阻 对发病机制的认识。自噬和突触传递的动态平衡调节的变化 不仅与帕金森病有关，而且还与生理衰老有关。富含亮氨酸的重复蛋白2(LRRK2)是一种主要的 神经节桥接自噬和帕金森病发病机制的候选基因。LRRK2的突变是最常见的 帕金森病的遗传原因和LRRK2激酶活性的增加也与特发性帕金森病有关。的确有 越来越多的证据表明，多条导致帕金森病的途径可能汇聚在一起，通过 机制依赖于LRRK2的活性。最近，LRRK2被证明可以磷酸化Rab的一个子集 GTP酶，为在了解机制方面取得进展提供了重要机会 LRRK2下游。这项提议的目的是阐明LRRK2在自噬中可能扮演的角色 和突触动态平衡，在与帕金森病相关的致病突变的背景下。我们的初步数据 提示LRRK2中最常见的致病突变p.G2019S破坏了自噬小泡(AV) 啮齿动物和ipsc来源的人类神经元的轴突运输。我们假设多重致病因素 PD突变破坏自噬和突触小泡前体(SVP)转运机制 依赖于LRRK2激酶活性的增加。为了验证这一假设，我们将使用IPSC来源的神经元 作为人类疾病的模型。目标1a中提出的实验将探索LRRK2-p.G2019S是否会导致 作为神经退行性变的潜在机制，动静脉管降解的缺陷。在目标1b中，我们将确定 无论是VPS35-p.D620N突变，还是增加LRRK2活性的不同致病PD突变， 导致与LRRK2-p.G2019S类似的自噬缺陷。最后，在目标2中，我们将探索SVP 从胞体到轴突的运输受到导致LRRK2过度活动的突变的损害，具有潜在的 对突触动态平衡的影响。总的来说，我们期望这些目标将有助于阐明机制。 帕金森病的多种病因可以汇聚到依赖LRRK2的通路上，从而扰乱神经元自噬 以及突触的动态平衡。此外，这项工作可能会为今后的工作提供一个基础，以供参考 在没有衰老疾病的情况下，生理衰老改变这些过程的途径。至 补充这个研究计划，一个全面的培训计划将帮助受训者满足特定的研究 目标、专业目标(包括写作、指导和演示)和临床目标(捆绑在一起 医生-科学家综合培训路径)，所有这些都是在支持性、协作性科学环境中进行的。