Mitochondrial Fidelity in Mammalian Neurons

哺乳动物神经元的线粒体保真度

• 批准号: 10592168
• 负责人: Ewa Karolina Bomba-Warczak
• 金额: $ 12.37万
• 依托单位: NORTHWESTERN UNIVERSITY AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-01-01 至 2024-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10592168
• 关键词: Aging; Amino Acids; Animals; Architecture; Axon; Biogenesis; Biology; Brain; Buffers; Calcium; Cell Death; Cell physiology; Cells; Complex; Crista ampullaris; DNA; Dendrites; Docking; Energy-Generating Resources; Gene Expression; Gene Proteins; Goals; Half-Life; Heart; Homeostasis; Impairment; Investigation; Kinetics; Label; Link; Longevity; Maintenance; Mass Spectrum Analysis; Measures; Membrane; Metabolic; Metabolism; Methods; Microfluidic Microchips; Mitochondria; Mitochondrial DNA; Mitochondrial Proteins; Molecular; Molecular Target; Morphology; Mus; Nerve Degeneration; Neurodegenerative Disorders; Neurodevelopmental Disorder; Neuroglia; Neurons; Nuclear; Nuclear Pore Complex; Optics; Organelles; Pattern; Phase; Physiologic pulse; Play; Positioning Attribute; Process; Production; Protein Biosynthesis; Proteins; Proteome; Proteomics; Quality Control; Rejuvenation; Research; Research Proposals; Role; Site; Stable Isotope Labeling; Stimulation of Cell Proliferation; Structure; Synapses; Techniques; Tissues; Translations; Tubular formation; age related neurodegeneration; experimental study; fitness; fluorescence imaging; genetic manipulation; genome integrity; insight; mitochondrial dysfunction; mitochondrial fitness; mitochondrial genome; nervous system disorder; novel; postmitotic; preservation; protein degradation; ribosome profiling; spatiotemporal; superresolution microscopy; ultra high resolution

Summary Mitochondria are multifaceted organelles that play vital roles in a myriad of cellular functions, including energy production, metabolism, calcium homeostasis, and cell death. It is generally accepted that a decline in mitochondria quality is a key contributor to mitochondrial dysfunction, aging, and represents a key point of convergence for several neurological disorders. Yet, precisely how dysfunctional mitochondria contribute to these conditions remains elusive. Mitochondria are thought to be constantly rejuvenated via collaborative processes of mitogenesis, fission-fusion, and multi-level quality-control mechanisms. Accordingly, the average half-life of mitochondrial proteins in the brain has been estimated at less than 3 weeks. Recently, I identified a discrete number of mitochondrial long-lived proteins (mt-LLPs) that last at least four months in mouse brain and heart. These long-lived mitochondrial proteins (mt-LLPs) include OxPhos complexes and several mitochondrial cristae associated proteins, which similarly to other architecturally stable and long-lived structures (i.e. nuclear pore complexes) are recognized for their highly defined and elaborate ultrastructure. Therefore, we hypothesized that the exceptional longevity of mt-LLPs could play an essential role in the long-term stabilization of the mitochondrial cristae in long-lived, post-mitotic cells. The goal of this research proposal is to delineate the localization of mt-LLPs within mitochondria in neurons, examine their temporal dynamics and integration with newly synthesized proteins, and investigate their potential contribution to mitochondrial fitness and long-term cristae stability. In Aim 1, using a combination of pulse-chase protein labeling methods, super-resolution fluorescent imaging and mass spectrometry I propose to (1) examine the spatio-temporal dynamics of mt-LLPs in axonal and somato-dendritic domains of primary neurons. In Aim 2, we propose to extend our analysis to include mitochondrial DNA (mtDNA) by investigating the coordination between mt-LLPs enrichment and mtDNA longevity neurons. In Aim 3, I will investigate the mechanism(s) involved in persistence of mt-ELLPs in neurons using genetic manipulations targeting mitochondrial cristae stability. Lastly, in Aim 4 we will begin the investigation into the coordination between nuclear and mitochondrial genome expression in neurons. In summary, insights from the proposed experiments will significantly advance our understanding of long-term of mitochondrial proteome homeostasis and genome integrity in neurons, which could provide with new molecular targets for modulating the mitochondrial network dynamics in the processes of neurodegeneration.

概括 线粒体是多方面的细胞器，在多种细胞功能中发挥着至关重要的作用，包括能量 生产、代谢、钙稳态和细胞死亡。人们普遍认为， 线粒体质量是线粒体功能障碍、衰老的关键因素，也是线粒体功能障碍的关键点。 多种神经系统疾病的收敛。然而，功能失调的线粒体究竟是如何导致 这些条件仍然难以捉摸。线粒体被认为可以通过协作不断恢复活力 有丝分裂、裂变融合过程和多级质量控制机制。因此，平均 据估计，大脑中线粒体蛋白的半衰期不到三周。最近，我发现了一个 离散数量的线粒体长寿命蛋白（mt-LLP）在小鼠大脑中持续至少四个月 心。这些长寿命线粒体蛋白 (mt-LLP) 包括 OxPhos 复合物和多种线粒体蛋白 嵴相关蛋白，与其他结构稳定且长寿的结构（即核 孔复合体）因其高度明确和复杂的超微结构而受到认可。因此，我们假设 MT-LLP 的超长寿命可以在长期稳定经济中发挥重要作用 长寿的有丝分裂后细胞中的线粒体嵴。 这项研究计划的目标是描绘 mt-LLP 在神经元线粒体内的定位， 检查它们的时间动态以及与新合成蛋白质的整合，并研究它们的潜力 对线粒体健康和长期嵴稳定性的贡献。在目标 1 中，使用脉冲追踪的组合 蛋白质标记方法、超分辨率荧光成像和质谱我建议 (1) 检查 原代神经元轴突和体树突域中 mt-LLP 的时空动态。瞄准 2，我们建议通过调查协调来扩展我们的分析以包括线粒体DNA（mtDNA） mt-LLP 富集和 mtDNA 长寿神经元之间的关系。在目标 3 中，我将研究其机制 使用针对线粒体嵴的基因操作参与神经元中 mt-ELLP 的持久存在 稳定。最后，在目标 4 中，我们将开始研究核与线粒体之间的协调 神经元中的基因组表达。总之，所提出的实验的见解将显着推进 我们对神经元线粒体蛋白质组稳态和基因组完整性的长期理解， 可以提供新的分子靶标来调节过程中的线粒体网络动态 神经退行性变。