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: 10340724
• 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/10340724
• 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; base; 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.

项目概要 线粒体对于细胞功能和生物体活力至关重要。这些细胞器以其自身的功能而闻名。 ATP 的产生是大多数真核细胞的主要能量货币，但较少为人所知。 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 信号级联，作为钙汇，也是铁的主要储存和利用场所 为了发挥这些不同的功能，线粒体必须正确定位在所有细胞中。 细胞器对于神经元来说尤其重要，神经元具有高度代谢活性、电极化和 可能具有巨大的体积，使得线粒体群体的调节特别具有挑战性。 可能是由于该细胞的高代谢需求，线粒体定位的精确控制和 维持线粒体健康对于神经元存活至关重要。 健康和功能与许多神经退行性疾病有关，包括阿尔茨海默病。 阿尔茨海默病、线粒体钙负荷缺陷以及与内质网的接触都具有 此外，早期患者的先进神经影像显示线粒体缺陷。 功能，使得了解神经元中线粒体功能如何维持至关重要 了解疾病生物学在过去的几十年里已经揭示了令人着迷的见解。 神经元中的线粒体生物学，我们仍然没有彻底了解神经元群体如何 线粒体在神经元的漫长寿命中得到维持，对于保持健康至关重要。 细胞器从细胞体进入长轴突，轴突可以从细胞体延伸一米 人类离线时，逆行运输将老化或受损的细胞器移向细胞体。 受损的细胞器到达细胞体，其中一些会经历定向降解。 细胞器和健康线粒体的来源尚未确定。我们开发了一种体内系统。 为了解决该领域长期存在的问题，我们可以使用斑马鱼神经元对线粒体进行成像。 我们开发了转基因品系，在完整的神经回路中进行体内定位、健康和运输。 遗传工具和成像方法可单独标记线粒体以跟踪它们并追踪它们的寿命 以及神经元中的生物发生，这将使我们能够确定健康线粒体的来源。 独立地，我们设计了一种策略来定义神经元数量。 运动线粒体附着机制对于细胞器的逆行运输特别必需 （目标 2）。所提出的实验将提供关于线粒体如何以及为何发生的机制见解。 朝着逆行方向移动，同时也确定了健康细胞器所需的来源 所获得的知识将增强我们对神经元线粒体群的维持的认识。 细胞的基本生物学可以重新用于潜在的治疗干预。