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: 9134906
• 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/9134906
• 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; Genetic screening method; Goals; Guanosine Triphosphate Phosphohydrolases; Homeostasis; Human; In Vitro; Kidney; Knockout Mice; Knowledge; LRRK2 gene; Link; Lysosomes; Mediating; Membrane Protein Traffic; Molecular; Molecular Genetics; Mus; Mutation; Neurites; Neurons; Organelles; Outcome; Parkinson Disease; Pathogenesis; Pathway interactions; Phenocopy; Phosphatidylinositols; Phosphotransferases; Process; Protein-Serine-Threonine Kinases; Proteins; Recycling; Regulation; Reporting; Research; Rodent; Rodent Model; Role; SNAP receptor; Structure; Testing; Therapeutic; Transgenic Mice; Transgenic Organisms; abstracting; age related; aged; alpha synuclein; base; 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.

项目总结/摘要 本研究旨在阐明自噬-溶酶体机制在帕金森病发病机制中的作用。 PD的早期病理学分析和PD连锁基因的最新研究，如SNCA，LRRK 2，Parkin， Pink 1、GBA和ATP 13 A2的表达提示自噬-溶酶体通路功能障碍在PD发病机制中的作用。 最近的证据表明，抑制LRRK 2或LRRK 2 PD突变体的表达会引起异常的细胞凋亡。 自噬活性，但详细机制尚不清楚。我们的初步研究表明LRRK 2与 一种自噬激酶，其是自噬所必需的并且是轴突/神经突生长所需的。这里我们 建议研究LRRK 2通过直接调节自噬的分子机制， 靶向自噬机制和功能失调的自噬作为潜在的PD致病途径。我们 先前报道，小鼠自噬的破坏导致内源性 α-Syn在营养不良的轴突和改变的多巴胺传递中，与受损的自噬一致， 失败的细胞机制参与PD的发病机制。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， 是突触核病传播的基础原纤维α-Syn可以通过外泌体和/或 自噬体相关结构。此外，增加自噬基因beclin 1或转录因子， TFEB表达促进α-Syn的自噬清除，并在啮齿动物模型中提供神经保护。 然而，细胞内α-Syn自噬清除的确切机制仍然很差 表征了最后，LRRK 2是否也通过调节α-Syn的稳态来控制α-Syn的稳态， 还不清楚。鉴于自噬在α-Syn胞吐中的作用，我们假设， 自噬通过降解和分泌途径调节α-Syn清除; LRRK 2调节α-Syn清除。 通过靶向自噬来实现Syn体内平衡。在项目3中，我们提出（1）确定分子和遗传 LRRK 2介导的自噬调控的基础。我们将使用生物化学、细胞和动物模型， 剖析LRRK 2野生型和PD突变G2019 S在自噬控制中的作用， 自噬激酶和SNARE相关蛋白运输;（2）确定自噬的机制， 和LRRK 2通过靶向多种运输途径调节α-Syn稳态。我们将应用 多学科方法来测试LRRK 2和自噬通路会聚以调节α-Syn 通过在PD的细胞和动物模型中靶向分泌和降解来实现体内平衡。我们的项目3将是 与沈杰博士和汤姆·苏德霍夫博士密切合作，他们在以下方面拥有丰富的经验： LRRK 2和α-Syn研究。我们的项目3的完成预计将提供及时的知识 为了解LRRK 2的致病机制和开发潜在的治疗策略， 自噬-溶酶体途径清除α-突触核蛋白。