Elucidating Autophagy-lysosome Mechanism in LRRK2 and alpha-synuclein Pathogenic Pathways

阐明 LRRK2 和 α-突触核蛋白致病途径中的自噬溶酶体机制

• 批准号: 9297405
• 负责人: Zhenyu Yue
• 金额: $ 34.96万
• 依托单位: BRIGHAM AND WOMEN'S HOSPITAL
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/9297405
• 关键词: 1-Phosphatidylinositol 3-Kinase; Affect; Animal Model; Autophagocytosis; Autophagosome; Axon; Brain; Cell model; Collaborations; Complex; Data; Defect; Dopamine; Endosomes; Excision; Exocytosis; Gene Expression; Genes; Genetic; Goals; Guanosine Triphosphate Phosphohydrolases; Homeostasis; Human; Impairment; In Vitro; Kidney; Knockout Mice; Knowledge; LRRK2 gene; Link; Lysosomes; Mediating; Membrane; Molecular; Molecular Genetics; Mus; Mutation; Neurites; Neurons; Organelles; Outcome; Parkinson Disease; Pathogenesis; Pathogenicity; Pathologic; Pathway interactions; Phenocopy; Phosphatidylinositols; Phosphotransferases; Process; Protein-Serine-Threonine Kinases; Proteins; Recycling; Regulation; Reporting; Research; Rodent; Rodent Model; Role; SNAP receptor; Structure; Testing; Therapeutic; Time; Transgenic Mice; Transgenic Organisms; age related; aged; alpha synuclein; biochemical model; exosome; experience; in vivo; injured; interdisciplinary approach; mouse model; mutant; neuroprotection; neurotoxicity; overexpression; parkin gene/protein; protein aggregate; protein transport; trafficking; transcription factor; transmission process

Project Summary/Abstract Our goal is to elucidate autophagy-lysosomal mechanism in the pathogenesis of Parkinson's disease (PD). Early pathological analysis of PD and recent studies of PD-linked genes, such as SNCA, LRRK2, Parkin, Pink1, GBA and ATP13A2, implicates dysfunctional autophagy-lysosomal pathway in the pathogenesis of PD. Recent evidence shows that inhibition of LRRK2 or expression of LRRK2 PD mutants causes aberrant autophagic activity, but the detailed mechanism is unclear. Our preliminary study suggests a link of LRRK2 to an autophagy kinase, which is essential for autophagy and required for axon/neurite outgrowth. Here we propose to investigate the molecular mechanism whereby LRRK2 regulates autophagy through directly targeting autophagy machinery and dysfunctional autophagy as a potential PD pathogenic pathway. We previously reported that disruption of autophagy in mice leads to age-dependent accumulation of endogenous α-Syn in dystrophic axons and altered dopamine transmission, consist with impaired autophagy as one of the failing cellular mechanisms involved in the pathogenesis of PD. Emerging evidence suggests that autophagy not only participates in degradation of α-Syn, but also is involved in the secretion pathway of α-Syn, which underlies the spreading of synucleiopathy. Fibrillar α-Syn can be secreted through exosomes and/or autophagosome-related structures. Furthermore, increasing autophagy gene beclin1 or transcription factor TFEB expression facilitates the autophagic clearance of α-Syn and offers neuroprotection in rodent models. However, the precise mechanism for the autophagic clearance of intracellular α-Syn remains poorly characterized. Finally, whether LRRK2 also contributes to the control of α-Syn homeostasis through regulation of autophagy is unclear. Given the emerging role of autophagy in the exocytosis of α-Syn, we hypothesize that autophagy regulates α-Syn clearance through both degradative and secretory pathways; LRRK2 modulates α- Syn homeostasis by targeting autophagy. In Project 3 we propose (1) to determine molecular and genetic basis for LRRK2-mediated autophagy regulation. We will use biochemical, cellular and animal models to dissect the role for LRRK2 wildtype and PD mutation G2019S in autophagy control through modulating the autophagy kinase and SNARE-related protein trafficking; (2) to determine the mechanism that autophagy and LRRK2 modulate α-Syn homeostasis by targeting multiple trafficking pathways. We will apply multidisciplinary approaches to test that LRRK2 and autophagy pathway converge to regulate α-Syn homeostasis by targeting secretion and degradation in cell and animal models of PD. Our project 3 will be conducted in close collaboration with Drs. Jie Shen and Tom Südhof, who have extensive experience in LRRK2 and α-Syn research, respectively. Completion of our project 3 is expected to provide timely knowledge for understanding LRRK2 pathogenic mechanism and developing potential therapeutic strategies by targeting autophagy-lysosome pathways for the clearance of α-synuclein.

项目摘要/摘要 我们的目标是阐明自噬-溶酶体在帕金森病(PD)发病机制中的作用。 帕金森病的早期病理分析和与帕金森病相关的基因SNCA、LRRK2、Parkin、 PINK1、GBA和ATP13A2参与了自噬-溶酶体功能障碍的帕金森病发病机制。 最近的证据表明，抑制LRRK2或表达LRRK2 PD突变体会导致异常 自噬活动，但具体机制尚不清楚。我们的初步研究表明LRRK2与 一种自噬激酶，对自噬是必不可少的，对轴突/轴突的生长也是必需的。在这里我们 建议研究LRRK2通过直接调控自噬的分子机制 将自噬机制和功能失调的自噬作为潜在的帕金森病致病途径。我们 先前报道，破坏小鼠的自噬会导致内源性内源性激素的年龄依赖性积累 α-Syn在营养不良轴突和多巴胺传递改变中的作用，与自噬受损是一致的 失败的细胞机制参与了帕金森病的发病。新出现的证据表明，自噬 不仅参与α-Syn的降解，还参与α-Syn的分泌途径， 是联核症传播的基础。纤维状α-syn可通过外切体和/或 自噬相关结构。此外，增加自噬基因Beclin1或转录因子 在啮齿动物模型中，TFEB的表达有助于α-Syn的自噬清除，并提供神经保护作用。 然而，细胞内α-syn自噬清除的确切机制仍然很差。 特色化的。最后，LRRK2是否也通过调节参与了α-Syn动态平衡的控制 自噬的类型尚不清楚。鉴于自噬在α-syn胞吐中的新角色，我们假设 自噬通过降解和分泌途径调节α-Syn清除；LRRK2调节α- 通过靶向自噬来实现SYN的动态平衡。在项目3中，我们建议(1)确定分子和遗传 LRRK2介导的自噬调控的基础。我们将使用生化、细胞和动物模型来 分析LRRK2野生型和PD突变G2019S在自噬调控中的作用 自噬蛋白和圈套相关蛋白的运输；(2)确定自噬的机制 而LRRK2通过靶向多条转运途径调节α-Syn的动态平衡。我们会申请 多学科方法测试LRRK2和自噬途径融合调节α-Syn 帕金森病细胞和动物模型中靶向分泌和降解的动态平衡。我们的项目3将是 与沈杰博士和S博士密切合作，他们在 LRRK2和α-Syn研究。我们项目3的完成预计将提供及时的知识 通过靶向研究LRRK2致病机制和开发潜在的治疗策略 清除α-突触核蛋白的自噬-溶酶体途径。