CAREER: Mitochondrial Transcellular Communication in the Nervous System: Mechanisms of Action and Student Training Opportunities

职业：神经系统中的线粒体跨细胞通讯：作用机制和学生培训机会

• 批准号: 2235079
• 负责人: Martha Bhattacharya
• 金额: $ 110万
• 依托单位: University of Arizona
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-04-01 至 2028-03-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2235079&HistoricalAwards=false
• 关键词: CAREER; Mitochondrial; Transcellular; Communication; Nervous

Most neurons in your brain are irreplaceable and must function in their circuits for life. To maintain the brain health, stressed or damaged neurons must receive support from surrounding cells to increase their chances of survival. To communicate with each other, both neurons and non-neuronal cells called glia release molecules that communicate their health status and elicit appropriate responses. Remarkably, one of the communication strategies that glia and neurons use involves the transfer of entire cellular organelles called mitochondria whose primary job is to produce energy. While the transfer of healthy, intact mitochondria improves neuronal function, the transfer of faulty mitochondria is toxic. How glia and neurons coordinate requests for and deliveries of mitochondria to ensure brain health is an unanswered question but one of vital importance. This project will elucidate the triggers for mitochondrial transfer, the cellular machinery used in their release, and the uptake mechanisms that integrate mitochondria into recipient cells. In doing so, the research will provide a window into a key process that could in the future be exploited to improve brain function throughout life. To perform aspects of this project, undergraduate students will participate in a unique credit-bearing, team-based research experience focused on neuron-glia communication and using the fruit fly as a model system. Undergraduate students will also participate in an outreach event to local elementary and middle school students. Taken together, the project will reveal new modes of cellular communication that underlie brain health and will provide training opportunities for the future scientific workforce.This project will establish the mechanisms and regulation of mitochondrial trans-cellular transfer (mitoTCT) in vivo by deploying an innovative combinatorial strategy of genetics, 3D microscopy, and imaging flow cytometry (iFACS) in the Drosophila nervous system. Using dual binary expression systems, neuronal and glial membranes and mitochondria will be labeled with four colors, facilitating unambiguous identification of the sources and directions of mitoTCT. In Aim 1, the project will elucidate key regulators of mitoTCT rate in vivo. This aim will test the hypothesis that nerve injury and/or excess neuronal activity can trigger mitoTCT from glia to neurons. In Aim 2, the project will determine the mechanism(s) by which mitochondria are transferred between glia and neurons. Three proposed modes of transfer (tunneling nanotubes, extracellular vesicles, and release of free mitochondria) will be evaluated by inhibition of each mechanism in a cell type specific manner. In both aims, the health status of mitochondria will be evaluated using genetically encoded redox sensors, which will determine whether the mode of action is leading to rescue or toxicity of recipient cells. This research will advance fundamental knowledge of neuron-glia communication via mitochondria and will illuminate how we might harness mitochondrial transfer for the benefit of neuronal health.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

你大脑中的大多数神经元都是不可替代的，必须在它们的回路中终生发挥作用。为了保持大脑健康，受到压力或受损的神经元必须得到周围细胞的支持，以增加它们的生存机会。为了相互交流，神经元和非神经元细胞（称为神经胶质细胞）都会释放分子，以传达其健康状况并引发适当的反应。值得注意的是，神经胶质和神经元使用的通信策略之一涉及称为线粒体的整个细胞器的转移，其主要工作是产生能量。虽然转移健康、完整的线粒体可以改善神经元功能，但转移有缺陷的线粒体是有毒的。神经胶质细胞和神经元如何协调线粒体的需求和交付，以确保大脑健康是一个尚未回答的问题，但至关重要。该项目将阐明线粒体转移的触发因素，其释放中使用的细胞机制，以及将线粒体整合到受体细胞中的摄取机制。在这样做的过程中，这项研究将为一个关键过程提供一个窗口，这个关键过程可以在未来被利用来改善整个生命的大脑功能。为了执行这个项目的各个方面，本科生将参加一个独特的学分，以团队为基础的研究经验，重点是神经胶质细胞的通信和使用果蝇作为模型系统。本科生还将参加一个面向当地中小学生的外联活动。总之，该项目将揭示大脑健康的细胞通讯新模式，并为未来的科学工作者提供培训机会。该项目将通过在果蝇神经系统中部署遗传学、3D显微镜和成像流式细胞术（iFACS）的创新组合策略，建立体内线粒体跨细胞转移（mitoTCT）的机制和调控。使用双二元表达系统，神经元和神经胶质细胞膜和线粒体将被标记有四种颜色，便于明确识别mitoTCT的来源和方向。在目标1中，该项目将阐明体内mitoTCT速率的关键调节因子。这一目标将测试神经损伤和/或过度的神经元活动可以触发从神经胶质到神经元的mitoTCT的假设。在目标2中，该项目将确定线粒体在神经胶质细胞和神经元之间转移的机制。将通过以细胞类型特异性方式抑制每种机制来评价三种拟议的转移模式（隧道纳米管、细胞外囊泡和游离线粒体的释放）。在这两个目标中，线粒体的健康状况将使用遗传编码的氧化还原传感器进行评估，这将确定作用模式是否导致受体细胞的拯救或毒性。这项研究将推进神经胶质细胞通过线粒体通信的基础知识，并将阐明我们如何利用线粒体转移对神经元健康的好处。该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。