Pathogenesis of TRPV4-related peripheral neuropathy

TRPV4相关周围神经病变的发病机制

• 批准号: 10226055
• 负责人: Brett Andrew McCray
• 金额: $ 19.98万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-15 至 2023-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10226055
• 关键词: Address; Affect; Afferent Neurons; Agonist; Axon; Axonal Neuropathy; Binding; Biological Models; Calcium; Calcium Signaling; Cations; Cell membrane; Cells; Charcot-Marie-Tooth Disease; Cultured Cells; Cytoskeletal Proteins; Cytoskeleton; Data; Dendrites; Development; Disease; Drosophila genus; Drug Targeting; Environment; Epithelial Cells; Foundations; Future; Genes; Growth Cones; Health; Histologic; Image; Impairment; Inherited; Ion Channel; Ion Channel Gating; Knock-in Mouse; Knock-out; Lead; Maintenance; Maps; Measures; Mediating; Mediator of activation protein; Membrane; Modeling; Morphogenesis; Morphology; Motor; Motor Neurons; Mus; Muscle Weakness; Mutation; N-terminal; Nerve Degeneration; Neurites; Neurons; Neuropathy; Pathogenesis; Pathway interactions; Peripheral Nerves; Peripheral Nervous System Diseases; Permeability; Pharmaceutical Preparations; Pharmacology; Phenotype; Play; Process; Protein Binding Domain; Proteins; Proteomics; Regulation; Role; Sensory; Signal Transduction; Stimulus; Surface; Therapeutic; Time; Toxic effect; Training; Transducers; Vanilloid; Viral; Work; base; career; career development; cell immortalization; combinatorial; cytotoxicity; design; disease-causing mutation; experimental study; extracellular; fly; genetic manipulation; in vivo; insight; knock-down; mouse model; mutant; nervous system disorder; neuron development; novel; overexpression; protein protein interaction; receptor; release of sequestered calcium ion into cytoplasm; repaired; small molecule; targeted treatment; therapeutic target; tool

PROJECT SUMMARY/ABSTRACT Charcot-Marie-Tooth (CMT) disease is the most common inherited neurologic disease worldwide and causes peripheral nerve degeneration with resultant progressive sensory loss and muscle weakness. Despite identification of over 80 causative genes, CMT lacks treatments due to incomplete understanding of disease mechanisms and a lack of rational drug targets. Mutations in TRPV4 (transient receptor potential vanilloid), a calcium-permeable non-selective ion channel, cause CMT type 2C (CMT2C). TRPV4 is unique in that it represents the only membrane-expressed ion channel in CMT and thus a potential therapeutic target. TRPV4 is known to regulate cytoskeletal changes in epithelial cells, but a similar role in neurons has not been established. As neuronal cytoskeletal changes are critical for neuronal development and maintenance and are regulated by calcium signaling, defining the role of TRPV4 in modulating neuronal cytoskeleton has important implications for the pathogenesis of CMT2C and potentially in other neurodegenerative conditions. Our collective preliminary work in cells, primary neurons, and flies suggests that TRPV4 can promote neurite outgrowth, but that this function is disrupted by neuropathy-causing mutations. We have also used unbiased proteomics to identify TRPV4 interacting proteins, including syndapin-1 and RhoA, which have known roles in regulating neuronal outgrowth. Specific Aim 1 will define how WT and mutant TRPV4 influence syndapin-1 and RhoA-dependent cytoskeletal remodeling pathways and examine reciprocal regulation of TRPV4 ion channel function and mutant toxicity. Specific Aim 2 will address the role of wild type and mutant TRPV4 in regulating neuronal morphogenesis in primary sensory and motor neurons. In Specific Aim 3, we will use a Drosophila model of TRPV4 neuropathy and our recently generated TRPV4 mutant knockin mice to interrogate the in vivo effects of neuropathy mutations. We will also examine whether genetic manipulation of RhoA and syndapin or pharmacologic manipulation of TRPV4 channel activity can alter neuronal phenotypes in flies. The experiments in this proposal will define the normal function of TRPV4 in neuronal cytoskeletal remodeling and morphogenesis, investigate specific pathogenetic mechanisms in TRPV4 neuropathy, and determine whether TRPV4 can be therapeutically targeted in vivo. Together, these studies will provide important insights into the role of TRPV4 in axonal health and disease and will inform future efforts to develop TRPV4-based therapeutic strategies for CMT2C and perhaps other forms of axonal neuropathy.

项目概要/摘要 腓骨肌萎缩症（CMT）是世界范围内最常见的遗传性神经系统疾病，其原因如下： 周围神经变性，导致进行性感觉丧失和肌肉无力。尽管 已鉴定出 80 多个致病基因，CMT 由于对疾病的了解不完全而缺乏治疗方法 机制和缺乏合理的药物靶点。 TRPV4（瞬时受体电位香草酸）突变， 钙渗透性非选择性离子通道，引起2C型CMT（CMT2C）。 TRPV4 的独特之处在于 代表 CMT 中唯一的膜表达离子通道，因此是潜在的治疗靶点。 TRPV4 已知可以调节上皮细胞中的细胞骨架变化，但在神经元中的类似作用尚未被证实 已确立的。由于神经元细胞骨架的变化对于神经元发育和维持至关重要，并且 TRPV4 受钙信号调节，确定 TRPV4 在调节神经元细胞骨架中的作用具有重要意义 对 CMT2C 发病机制以及其他神经退行性疾病的潜在影响。我们的 在细胞、初级神经元和果蝇中的集体初步工作表明 TRPV4 可以促进神经突 生长，但这种功能会被引起神经病的突变破坏。我们也使用了无偏 蛋白质组学鉴定 TRPV4 相互作用蛋白，包括 syndapin-1 和 RhoA，它们在 调节神经元的生长。具体目标 1 将定义 WT 和突变体 TRPV4 如何影响 syndapin-1 和 RhoA 依赖性细胞骨架重塑途径并检查 TRPV4 离子通道的相互调节 功能和突变体毒性。具体目标 2 将解决野生型和突变体 TRPV4 在调节中的作用 初级感觉和运动神经元的神经元形态发生。在具体目标 3 中，我们将使用果蝇 TRPV4 神经病模型和我们最近生成的 TRPV4 突变敲入小鼠来询问体内 神经病突变的影响。我们还将检查 RhoA 和 syndapin 的基因操作是否 TRPV4 通道活性的药理学操作可以改变果蝇的神经元表型。实验 该提案将定义TRPV4在神经元细胞骨架重塑中的正常功能和 形态发生，研究 TRPV4 神经病变的具体发病机制，并确定是否 TRPV4 可以在体内进行治疗靶向。总之，这些研究将为以下问题提供重要见解： TRPV4 在轴突健康和疾病中的作用，并将为未来开发基于 TRPV4 的治疗方法提供信息 针对 CMT2C 和其他形式的轴突神经病的策略。