Mechanism and function of retrograde mitochondrial transport in axons

轴突逆行线粒体转运的机制和功能

• 批准号: 10570955
• 负责人: Catherine M Drerup
• 金额: $ 37.54万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-02-15 至 2027-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10570955
• 关键词: Active Biological Transport; Adaptor Signaling Protein; Address; Afferent Neurons; Alzheimer' s Disease; Apoptotic; Axon; Binding; Biogenesis; Biological; Biological Assay; Biology; Biosensor; Calcium; Cardiolipins; Cell Culture Techniques; Cell physiology; Cells; Cellular biology; Data; Defect; Disease; Dynein ATPase; Endoplasmic Reticulum; Eukaryotic Cell; Genetic; Genetic Screening; Goals; Health; Homeostasis; Hour; Human; Image; In Vitro; Individual; Iron; Knowledge; Label; Life; Link; Lipid Binding; Lipids; Maintenance; Mediating; Metabolic; Mitochondria; Molecular; Motor; Mutate; Neurodegenerative Disorders; Neurons; Organelles; Organism; Outer Mitochondrial Membrane; Pathology; Pathway interactions; Patients; Population; Positioning Attribute; Process; Production; Proteins; Proteome; Protocols documentation; Recycling; Regulation; Role; Signal Transduction; Signaling Molecule; Site; Source; System; Testing; Therapeutic; Therapeutic Intervention; Transgenic Organisms; Work; Zebrafish; aged; anterograde transport; design; experimental study; fascinate; imaging approach; in vivo; in vivo imaging; induced pluripotent stem cell; insight; meter; mutant; neural circuit; neuroimaging; neuronal cell body; neuronal survival; retrograde transport; tool; transcriptome

Project Summary Mitochondria are essential for cellular function and organism viability. These organelles are well known for their production of ATP, the primary energy currency of most eukaryotic cells. Less well known are the plethora of other functions these organelles have including production of signaling molecules, regulation of apoptotic signaling cascades, serving as a calcium sink, and also being the primary storage and utilization site of iron in the cell. To serve these diverse functions, mitochondria must be properly localized in all cells; however, this organelle is particularly critical in neurons. Neurons are highly metabolically active, electrically polarized, and can have an enormous volume making regulation of the mitochondrial population particularly challenging. Likely due to the high metabolic demands of this cell, precise control of mitochondrial localization and maintenance of mitochondrial health are essential for neuronal survival. Abnormal mitochondrial localization, health, and function have been linked to many neurodegenerative diseases including Alzheimer’s disease. In Alzheimer’s, defects in mitochondrial calcium load and contacts with the endoplasmic reticulum have both been noted. Additionally, advanced neuroimaging of early-stage patients revealed defects in mitochondrial function, making understanding how mitochondrial function is maintained in neurons paramount to understanding disease biology. While the last several decades have revealed fascinating insights into mitochondrial biology in neurons, we still do not have a thorough understanding of how the population of mitochondria is maintained over the long life of the neuron. Anterograde transport is critical for bringing healthy organelles from the cell body into the long axonal process which can extend a meter from the cell body in humans. Conversely, retrograde transport moves aged or damaged organelles towards to cell body. Once damaged organelles reach the cell body, some undergo targeted degradation. The fate of the bulk of these organelles and the source of healthy mitochondria has not been defined. We have developed an in vivo system to address these long-standing questions in the field. Using zebrafish neurons, we can image mitochondrial localization, health, and transport in vivo in a fully intact neural circuit. We have developed transgenic lines, genetic tools, and imaging approaches to individually label mitochondria to track them and follow their lifetime and biogenesis in neurons. This will allow us to determine the source of healthy mitochondria necessary for maintenance of the population in neurons (Aim 1). Independently, we designed a strategy to define the mechanism of motor-mitochondria attachment specifically necessary for retrograde transport of the organelle (Aim 2). Together, the proposed experiments will provide mechanistic insight into how and why mitochondria move in the retrograde direction while also defining the source of healthy organelles necessary for maintenance of the mitochondrial population in neurons. The knowledge gained will enhance our insight into the basic biology of the cell that can be repurposed for potential therapeutic interventions.

项目摘要 线粒体是细胞功能和生物体生存所必需的。这些细胞器以其 ATP是大多数真核细胞的主要能量货币。不太为人所知的是， 这些细胞器具有的其他功能包括产生信号分子、调节细胞凋亡、调节细胞增殖、调节细胞凋亡。 信号级联，作为钙汇，也是铁的主要储存和利用场所， 牢房为了发挥这些不同的功能，线粒体必须适当地定位在所有细胞中;然而， 细胞器在神经元中尤其重要。神经元具有高度的代谢活性，电极化， 可以具有巨大的体积，使得线粒体群体的调节特别具有挑战性。 可能是由于这种细胞的高代谢需求，线粒体定位的精确控制和 线粒体健康的维持对于神经元存活是必不可少的。异常线粒体定位， 健康和功能与包括阿尔茨海默病在内的许多神经退行性疾病有关。在 阿尔茨海默氏症、线粒体钙负荷缺陷以及与内质网的接触两者兼而有之 被注意到了。此外，早期患者的高级神经影像学显示线粒体缺陷， 功能，了解线粒体功能如何在神经元中维持至关重要， 了解疾病生物学。虽然过去几十年揭示了迷人的见解 神经元中的线粒体生物学，我们仍然没有彻底了解 线粒体在神经元的长寿命中得以维持。顺行运输对于将健康的 细胞器从细胞体进入长轴突过程，长轴突过程可以从细胞体延伸一米， 人类相反，逆行运输将老化或受损的细胞器移向细胞体。一旦 当受损的细胞器到达细胞体时，一些细胞器进行靶向降解。其中大部分的命运 细胞器和健康线粒体的来源尚未确定。我们开发了一个体内系统 来解决这个领域长期存在的问题。利用斑马鱼神经元，我们可以成像线粒体 定位、健康和在完全完整的神经回路中的体内运输。我们已经开发出转基因品系， 遗传工具和成像方法来单独标记线粒体，以跟踪它们并跟踪它们的寿命 和神经元的生物发生。这将使我们能够确定健康线粒体的来源， 维持神经元中的群体（目的1）。独立地，我们设计了一个策略来定义 细胞器逆行运输所必需的运动-线粒体附着机制 (Aim 2）。总之，拟议中的实验将提供线粒体如何以及为什么的机制见解 在逆行的方向移动，同时也定义了必要的健康细胞器的来源， 维持神经元中的线粒体群体。所获得的知识将增强我们对 细胞的基本生物学可以被重新用于潜在的治疗干预。