Pathogenesis of TRPV4-related peripheral neuropathy

TRPV4相关周围神经病变的发病机制

• 批准号: 9980503
• 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/9980503
• 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.

项目总结/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， 周围神经变性，导致进行性感觉丧失和肌肉无力。尽管 CMT鉴定了80多个致病基因，但由于对疾病的不完全了解， 机制和缺乏合理的药物靶点。TRPV 4（瞬时受体电位香草酸）突变，a 钙渗透性非选择性离子通道，导致CMT 2C型（CMT 2C）。TRPV 4的独特之处在于它 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 已知其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发现。 确立了习由于神经元细胞骨架的变化对于神经元的发育和维持至关重要， 通过钙信号调节，确定TRPV 4在调节神经元细胞骨架中的作用具有重要意义。 CMT 2C的发病机制和潜在的其他神经退行性疾病的影响。我们 在细胞、原代神经元和果蝇中的集体初步研究表明，TRPV 4可以促进神经突生长， 但是这种功能被引起神经病变的突变所破坏。我们还使用了无偏 蛋白质组学鉴定TRPV 4相互作用蛋白，包括syndapin-1和RhoA，它们在 调节神经元生长具体目标1将定义WT和突变体TRPV 4如何影响syndapin-1， RhoA依赖的细胞骨架重塑途径及TRPV 4离子通道的相互调节 功能和突变毒性。具体目标2将解决野生型和突变型TRPV 4在调节细胞凋亡中的作用。 初级感觉和运动神经元中的神经元形态发生。在《特定目标3》中，我们将使用果蝇 TRPV 4神经病模型和我们最近产生的TRPV 4突变敲入小鼠，以询问体内 神经病变突变的影响。我们还将研究RhoA和syndapin的基因操作或 TRPV 4通道活性的药理学操作可以改变果蝇中的神经元表型。实验 在这个提议中，将定义TRPV 4在神经元细胞骨架重塑中的正常功能， 形态发生，研究TRPV 4神经病的特定发病机制，并确定是否 TRPV 4可以在体内治疗靶向。总之，这些研究将提供重要的见解， TRPV 4在轴突健康和疾病中的作用，并将为未来开发基于TRPV 4的治疗药物提供信息。 CMT 2C和其他形式的轴突神经病的治疗策略。