Dysfunctional astroglial exosome to (motor) neuron axon signaling in ALS

ALS 中星形胶质细胞外泌体与（运动）神经元轴突信号传导功能失调

• 批准号: 10364034
• 负责人: Yongjie Yang
• 金额: $ 42.31万
• 依托单位: TUFTS UNIVERSITY BOSTON
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-02-01 至 2027-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10364034
• 关键词: ALS patients; Adhesions; Affect; Amyotrophic Lateral Sclerosis; Animal Model; Astrocytes; Autopsy; Axon; Biochemical; Brain; Caliber; Cell Adhesion Molecules; Cell Line; Conditioned Culture Media; Data; Dendritic Spines; Disease; Endosomes; Energy Supply; Focal Adhesion Kinase 1; Functional disorder; Growth Cones; Health; Human; Image; Inflammatory; Infusion procedures; Injections; Integrins; Knowledge; Mediating; Methods; Microfluidics; Modeling; Molecular; Molecular Biology; Molecular Motors; Molecular Sieve Chromatography; Morphology; Motor; Motor Neurons; Multivesicular Body; Mus; Mutation; N-Cadherin; Neuraxis; Neurodegenerative Disorders; Neuroglia; Neurons; Outcome; Pathogenesis; Pathology; Pathway interactions; Peripheral Nerves; Pharmacology; Phosphotransferases; Play; Property; Proteins; Proteomics; Reporter; Role; Signal Transduction; Spinal; Spinal Cord; Structure; Testing; Tissue Model; Transgenic Organisms; Ultracentrifugation; Virus; axon growth; axon guidance; axonal degeneration; base; cell type; cytokine; excitotoxicity; exosome; extracellular vesicles; functional loss; induced pluripotent stem cell; loss of function; motor disorder; motor impairment; mouse genetics; mutant; neuronal cell body; neurotransmission; novel; protective effect; protein transport; selective expression; superoxide dismutase 1; synaptogenesis; vesicular release

Abstract Dysfunctions of motor neuron (MN) axons that form both descending motor tracts and peripheral nerve tracts are widely observed in amyotrophic lateral sclerosis (ALS), which often precede MN soma (and axon) degeneration and significantly contribute to disease pathology. Although astroglial adhesion signals are essential for proper axon growth and guidance, whether and how glial adhesion molecules play a role in axon dysfunction/degeneration in ALS remains largely unknown. Although astroglia conditioned medium (ACM) derived from the mouse SOD1 mutant model or from human ALS patient brain astroglia is able to substantially modulate health and survival of MNs, astroglial factors in ACM that modulate MN survival in ALS conditions remain essentially unidentified. Exosomes (50-150 nm in diameter), a major type of secreted extracellular vesicles (EVs), are released from multivesicular bodies (MVBs, an intermediate endosome structure) during endosome maturation. EVs and exosomes secreted from central nervous system (CNS) cell types have emerged as an important intercellular pathway that is implicated in the pathogenesis of neurodegenerative diseases including ALS. How astroglia-derived exosomes affect (motor) neuron survival especially axon properties in ALS remains largely unexplored. In this project, we intend to investigate novel stimulatory and protective roles of astroglial exosomes, especially exosomal adhesion molecule HepaCAM signaling to neurons, in promoting axon growth, functions, and (motor) neuron survival. We will also determine whether dysfunctional HepaCAM signaling from SOD1G93A astroglial exosomes to (motor) neurons contributes to MN axon dysfunction and degeneration in ALS. Based on our preliminary results, we propose the following aims in this project: Aim 1: Determine the effect of astroglial exosomes on (motor) neuron axon growth and functions; Aim 2: Investigate loss-of-function of astroglial exosome signaling to (motor) neurons in ALS models; Aim 3: Elucidate HepaCAM-mediated astroglial exosome signaling to (motor) neurons in ALS models; We have generated a large amount of preliminary data to support our rationales and to demonstrate feasibility for proposed aims. We will employ mouse genetics, primary neuron and astroglial cultures, molecular biology, virus injections, various imaging, and biochemical approaches to complete these aims. Outcomes from this project will reveal a new astroglial exosomal HepaCAM-mediated mechanism in modulating (motor) neuron axon growth and survival. It will also provide important knowledge about the loss-of-functional effect of astroglial exosomes in ALS. These studies will significantly advance our understanding of the astroglial dysfunction in ALS and help develop new astroglia- based neuroprotective strategies.

抽象的 形成下降运动束和周围神经的运动神经元 (MN) 轴突功能障碍 束在肌萎缩侧索硬化症 (ALS) 中广泛观察到，通常先于 MN 体细胞（和轴突） 变性并显着促进疾病病理学。尽管星形胶质细胞粘附信号很重要 为了正确的轴突生长和引导，神经胶质粘附分子是否以及如何在轴突中发挥作用 ALS 的功能障碍/退化仍然很大程度上未知。虽然星形胶质细胞条件培养基（ACM） 源自小鼠 SOD1 突变模型或人类 ALS 患者脑星形胶质细胞能够显着 调节 MN 的健康和生存，ACM 中的星形胶质细胞因子可调节 ALS 条件下的 MN 生存 基本上仍然身份不明。外泌体（直径 50-150 nm），一种主要的分泌型细胞外物质 囊泡 (EV) 是从多囊泡体（MVB，一种中间内体结构）释放的 内体成熟。中枢神经系统（CNS）细胞类型分泌的EV和外泌体已经出现 作为重要的细胞间途径，参与神经退行性疾病的发病机制 包括肌萎缩侧索硬化症（ALS）。星形胶质细胞来源的外泌体如何影响 ALS 中（运动）神经元的存活，尤其是轴突特性 很大程度上仍未被探索。在这个项目中，我们打算研究新的刺激和保护作用 星形胶质细胞外泌体，特别是外泌体粘附分子 HepaCAM 向神经元发出信号，促进轴突 生长、功能和（运动）神经元存活。我们还将确定 HepaCAM 信号传导是否功能失调 从 SOD1G93A 星形胶质细胞外泌体到（运动）神经元导致 MN 轴突功能障碍和变性 在肌萎缩侧索硬化症中。 根据我们的初步结果，我们提出本项目的以下目标： 目标 1：确定 星形胶质细胞外泌体对（运动）神经元轴突生长和功能的影响；目标 2：调查功能丧失 ALS 模型中星形胶质细胞外泌体向（运动）神经元发出信号；目标 3：阐明 HepaCAM 介导的 ALS 模型中星形胶质细胞外泌体向（运动）神经元发出信号；我们已经产生了大量的 初步数据支持我们的理由并证明拟议目标的可行性。我们将聘用 小鼠遗传学、原代神经元和星形胶质细胞培养、分子生物学、病毒注射、各种成像，以及 生化方法来完成这些目标。该项目的结果将揭示一个新的星形胶质细胞 外泌体 HepaCAM 介导的调节（运动）神经元轴突生长和存活的机制。它还将 提供有关 ALS 中星形胶质细胞外泌体功能丧失效应的重要知识。这些研究 将显着增进我们对 ALS 星形胶质细胞功能障碍的理解，并有助于开发新的星形胶质细胞 基于神经保护的策略。