Regulation of neuronal calcium transfer between mitochondria and lysosomes in health and neurodegeneration.

健康和神经变性中线粒体和溶酶体之间神经元钙转移的调节。

• 批准号: 9908598
• 负责人: Wesley J. Peng
• 金额: $ 5万
• 依托单位: NORTHWESTERN UNIVERSITY AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-30 至 2023-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9908598
• 关键词: Apoptosis; Automobile Driving; Biological Assay; Calcium; Cells; Data; Dementia; Development; Disease; Disease model; Electron Microscopy; Fostering; Functional disorder; Goals; Health; Homeostasis; Human; Image; Link; Lysosomes; Mediating; Membrane; Microscopy; Midbrain structure; Mitochondria; Modeling; Molecular; Mutation; Nerve Degeneration; Neurodegenerative Disorders; Neuroglia; Neurons; Optics; Organelles; Parkinsonian Disorders; Pathologic; Pathologic Processes; Pathway interactions; Patient-Focused Outcomes; Patients; Physicians; Physiological; Process; Production; Protocols documentation; Regulation; Research; Research Training; Resolution; Role; Scientist; Signal Transduction; Site; Syndrome; Techniques; aging brain; cell motility; cell type; dopaminergic neuron; human disease; improved; induced pluripotent stem cell; insight; live cell imaging; live cell microscopy; loss of function mutation; neurotransmitter release; new therapeutic target; novel; sensor

PROJECT SUMMARY Inter-organelle contact sites, which form dynamically between two different organelles and represent sites for metabolite transfer, have become increasingly appreciated as essential regulators of cellular homeostasis. Recently, our lab identified novel membrane contact sites between mitochondria and lysosomes in non-neuronal cells, which allow for bidirectional regulation of lysosomal and mitochondrial dynamics including mitochondrial fission and highlight a new pathway through which the two organelles can interact. Interestingly, both mitochondria and lysosomes are implicated in cellular calcium homeostasis, and dysfunction in both organelles has been linked to neurodegenerative disease. Calcium homeostasis is particularly important in neurons, where in addition to regulating functions such as ATP production and cellular signaling, calcium also modulates excitability and neurotransmitter release, suggesting that a more tightly-regulated mechanism of calcium transfer between organelles could be beneficial in neuronal cell types. Importantly, our preliminary data in non-neuronal cells suggest that activation of lysosomal calcium release increases mitochondrial calcium and that disruption of mitochondria-lysosome contact sites alters these calcium dynamics. Given these data, elucidating if and how mitochondria-lysosome contact sites transfer calcium in neurons will be critical for understanding how calcium dyshomeostasis may contribute to pathologic processes such as neurodegeneration. In this project, I propose to investigate the mechanisms and regulation of calcium dynamics at mitochondria-lysosome contact sites and their subsequent dysfunction in neurodegenerative disease using advanced microscopy techniques including super-resolution live cell microscopy and calcium imaging in long-term cultures of human induced pluripotent stem cell (iPSC)-derived neurons. In Aim 1, I will investigate the mechanisms of bidirectional calcium transfer at mitochondria-lysosome contact sites using human-derived cortical neurons. Additionally, as several lysosomal calcium transporters, including ATP13A2, have been implicated in neurodegenerative diseases, dysregulation of calcium dynamics between the two organelles may represent a potential pathway driving neurodegeneration. In Aim 2, I will investigate how disease-linked loss-of-function mutations in ATP13A2, which cause Kufor-Rakeb syndrome, an atypical form of parkinsonism with dementia, alter mitochondria-lysosome contact site dynamics and calcium homeostasis, and further contribute to downstream dysfunction in both organelles in patient-derived cortical and midbrain dopaminergic neurons. Together, the proposed research and training plan will offer important opportunities to not only acquire new experimental techniques in advanced imaging and human disease modeling to foster my development as a physician-scientist, but to also gain insight into the molecular mechanisms underlying neurodegeneration. A better understanding of these neuronal pathways will facilitate the identification of novel therapeutic targets, which may ultimately improve patient outcomes.

项目摘要 细胞器间接触位点，在两个不同的细胞器之间动态形成，代表位点 对于代谢物转移，作为细胞内稳态的基本调节剂已经越来越受到重视。 最近，我们的实验室在非神经元细胞中发现了线粒体和溶酶体之间的新的膜接触位点。 细胞，其允许双向调节溶酶体和线粒体动力学，包括线粒体 裂变，并突出了两个细胞器可以相互作用的新途径。有趣的是，两者 线粒体和溶酶体与细胞内钙稳态和两种细胞器功能障碍有关 与神经退行性疾病有关钙稳态在神经元中特别重要， 除了调节功能，如ATP的产生和细胞信号，钙也调节 兴奋性和神经递质的释放，这表明一个更严格的钙转移机制， 在神经元细胞类型中可能是有益的。重要的是，我们在非神经元的初步数据 细胞表明，激活溶酶体钙释放增加线粒体钙和破坏， 线粒体-溶酶体接触位点改变这些钙动力学。鉴于这些数据，阐明如果和如何 神经元中的钙-溶酶体接触位点转移钙对于理解钙如何在神经元中转移是至关重要的。 内分泌失调可能导致病理过程如神经变性。在这个项目中，我建议 研究钙离子在溶酶体接触位点的动力学机制和调节， 使用先进的显微镜技术， 人诱导多能干细胞长期培养中超分辨率肝细胞显微镜和钙成像 干细胞（iPSC）衍生的神经元。在目标1中，我将研究在体外条件下， 使用人源性皮质神经元的海马-溶酶体接触位点。此外，由于几个溶酶体 钙转运蛋白，包括ATP 13 A2，与神经退行性疾病、调节异常 这两个细胞器之间的钙动力学可能代表了一个潜在的途径驱动神经退行性变。 在目标2中，我将研究导致Kufor-Rakeb的ATP 13 A2中的疾病相关功能丧失突变是如何发生的。 帕金森综合征一种非典型形式伴痴呆，可改变海马-溶酶体接触部位动力学 和钙稳态，并进一步有助于下游功能障碍，在这两个细胞器在患者源性 皮质和中脑多巴胺能神经元。拟议的研究和培训计划将提供 重要的机会，不仅获得新的实验技术，在先进的成像和人类 疾病建模，以促进我作为一个医生，科学家的发展，但也获得深入了解分子 神经退行性变的潜在机制更好地理解这些神经通路将有助于 确定新的治疗靶点，这可能最终改善患者的预后。