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.

总结 线粒体是多方面的细胞器，在包括能量在内的无数细胞功能中发挥重要作用 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，并且代表了 几种神经系统疾病的融合。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。线粒体被认为是通过协作不断恢复活力， 有丝分裂过程、裂变融合和多层次质量控制机制。因此，平均 线粒体蛋白在脑中的半衰期估计不到3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， 心这些长寿线粒体蛋白（mt-LLP）包括OxPhos复合物和几种线粒体蛋白。 嵴相关蛋白，类似于其他结构稳定和长寿命的结构（即核 孔复合体）因其高度确定和精细的超微结构而被公认。因此，我们假设 中期有限责任合伙的特殊寿命可以在长期稳定 线粒体嵴在长寿，有丝分裂后的细胞。 这项研究计划的目标是描绘神经元线粒体内mt-LLP的定位， 检查它们的时间动态和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 蛋白质标记方法，超分辨率荧光成像和质谱我建议（1）检查 线粒体LLP在原代神经元轴突和体树突结构域的时空动态。在Aim中 2，我们建议通过调查协调，将我们的分析扩展到包括线粒体DNA（mtDNA）， 线粒体LLP富集和mtDNA长寿神经元之间的关系。在目标3中，我将研究机制（S） 使用针对线粒体嵴的遗传操作参与神经元中mt-ELLP的持久性 稳定最后，在目标4中，我们将开始研究细胞核和线粒体之间的协调 神经元中的基因组表达。总之，从拟议的实验中获得的见解将大大提高 我们对神经元中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点，用于调节线粒体网络动力学的过程， 神经退行性疾病