Validation of a new large-pore channel as a novel target for neuropathic pain

验证新的大孔通道作为神经性疼痛的新靶点

• 批准号: 10774593
• 负责人: Yun Guan
• 金额: $ 203.92万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-25 至 2026-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10774593
• 关键词: Adult; Affect; American; Analgesics; Anions; Anticoagulants; Astrocytes; Automobile Driving; Behavior; Biological Assay; Cells; Data; Dicumarol; Economic Burden; Electrophysiology (science); Evaluation; Exclusion; Exhibits; FDA approved; Gene Deletion; Genetic; Gliosis; Health Care Costs; Hyperactivity; Hypersensitivity; Individual; Inflammation Mediators; Inflammatory; Injury; Ion Channel; Knockout Mice; Knowledge; Libraries; Maintenance; Measures; Mechanics; Mediating; Microglia; Modality; Modeling; Molecular; Mus; Mutant Strains Mice; Neuromodulator; Neurons; Opiate Addiction; Opioid; Outcome; Pain; Pain management; Pathogenesis; Pathway interactions; Peripheral nerve injury; Persons; Pharmaceutical Preparations; Pharmacology Study; Posterior Horn Cells; Production; Productivity; Proliferating; Purinoceptor; RNA interference screen; Rattus; Reproducibility; Research Personnel; Role; Safety; Signal Transduction; Slice; Source; Spinal; Spinal Cord; Swelling; Synaptic Transmission; Syndrome; Testing; Translating; Validation; Vertebral column; Work; abuse liability; addiction; addiction liability; autocrine; behavior test; bench to bedside; chronic constriction injury; chronic pain; cytokine; effective therapy; experimental study; extracellular; genome-wide; glial activation; glial cell development; high throughput screening; improved; inhibitor; innovation; interdisciplinary approach; member; nerve injury; neuroinflammation; neuronal circuitry; new therapeutic target; novel; opioid epidemic; opioid overdose; pain inhibition; pain reduction; painful neuropathy; paracrine; patch clamp; pharmacologic; prescription opioid addiction; response; sex; spared nerve; sphingosine 1-phosphate; spontaneous pain; targeted treatment; transcriptome sequencing

PROJECT SUMMARY Neuropathic pain is a debilitating chronic pain syndrome, affecting ~25 million Americans. The estimated total economic burden of direct health care cost and lost productivity is ~$250 billion each year. Moreover, there has been a heavy-dependence on the prescription of opioids despite their poor long-term ability to manage pain. This contributes to the crisis of opioid overdoes and addictions. According to CDC, 187 people die every day in the U.S. from opioid overdoses. It is thus imperative to identify new therapeutic targets for safe pain treatment without abuse liability. Microgliosis and neuroinflammation have emerged as key drivers of neuropathic pain. In response to peripheral nerve injury, microglia in the spinal cord are activated and undergo proliferation. ATP is one of the most prominent activators of microglia. Upon stimulation of purinergic receptors, microglia release neuromodulators, which cause sensitization of the spinal neuronal circuits leading to chronic pain. Despite its central role in microglial activation, the source and the release mechanism of ATP remain poorly understood, especially after nerve injury. The rationale for this proposal is that blocking the source of exaggerated autocrine/paracrine ATP in the spinal cord after injury will provide an effective alternative to current strategies of targeting individual downstream purinergic receptors in neuropathic pain. Volume-Regulated Anion Channel (VRAC) is a member of the large-pore channel superfamily and its channel activity has been observed in microglia, making it a good candidate for ATP release. However, the molecular identity of VRAC was a mystery for over 3 decades. Through a genome- wide RNAi screen, we identified SWELL1 (aka, LRRC8A) as the only essential subunit of VRAC. Our preliminary data showed that 1) Swell1-dependent VRAC directly permeates ATP and can be activated by inflammatory mediator sphingosine 1-phosphate in BV2 microglia; 2) Microglia-specific Swell1 knockout mice showed reduced extracellular ATP enhancement in the spinal cord in a chronic constriction injury (CCI) model of neuropathic pain; 3) Importantly, the mutant mice also exhibited decreased spinal microgliosis, neuronal hyperactivity, and neuropathic pain-like behaviors after CCI. Based on these findings, we hypothesize that Swell1-containing VRAC releases ATP from microglia and mediates autocrine and paracrine purinergic signaling driving spinal microglia activation, neuroinflammation, and pain hypersensitivity after nerve injury. We have assembled a synergistic team of investigators and will use innovative and multidisciplinary approaches to test this hypothesis and will validate the Swell1 channel as a new target for neuropathic pain through genetic (Aim 1), mechanistic (Aim 2), and pharmacological (Aim 3) studies. Our study will generate important knowledge for validating and potentially translating novel Swell1- targeting therapies for neuropathic pain treatment and avoid the pitfalls of opioids.

项目摘要 神经性疼痛是一种使人衰弱的慢性疼痛综合征，影响约2500万美国人。估计 直接保健费用和生产力损失的经济负担每年约为2500亿美元。此外，委员会认为， 尽管阿片类药物的长期使用能力很差， 控制疼痛这导致了阿片类药物过量和成瘾的危机。根据CDC的数据，187人 在美国每天都有人死于阿片类药物过量因此，必须确定新的治疗靶点， 安全的疼痛治疗，无滥用责任。小胶质细胞增生和神经炎症已成为关键驱动因素 神经性疼痛作为对周围神经损伤的反应，脊髓中的小胶质细胞被激活， 进行扩散。ATP是小胶质细胞最重要的激活剂之一。刺激时 嘌呤能受体，小胶质细胞释放神经调质，引起脊髓神经元的敏化 导致慢性疼痛的回路尽管它在小胶质细胞激活中起着核心作用，但其来源和释放 ATP的作用机制仍不清楚，尤其是在神经损伤后。这项建议的理由是， 阻断损伤后脊髓中过度的自分泌/旁分泌ATP的来源将提供 当前针对单个下游嘌呤能受体策略的有效替代方案 神经性疼痛容积调节阴离子通道（VRAC）是大孔通道的一员 在小胶质细胞中已经观察到超家族及其通道活性，使其成为ATP的良好候选者 release.然而，VRAC的分子身份在30多年来一直是个谜。通过基因组- 通过广泛的RNAi筛选，我们鉴定了SWELL 1（aka，LRRC 8A）为VRAC的唯一必需亚基。我们 初步数据显示，1）溶胀1依赖性VRAC直接渗透ATP，并可被 BV 2小胶质细胞中的炎性介质鞘氨醇1-磷酸; 2）小胶质细胞特异性Swell 1敲除 在慢性压迫性损伤（CCI）中，小鼠脊髓细胞外ATP增强减少 神经病理性疼痛模型; 3）重要的是，突变小鼠还表现出脊髓小胶质细胞增生减少， CCI后神经元过度活跃和神经病理性疼痛样行为。基于这些发现，我们 假设含有Swell 1的VRAC从小胶质细胞释放ATP并介导自分泌和 驱动脊髓小胶质细胞活化、神经炎症和疼痛的旁分泌嘌呤能信号 神经损伤后的超敏反应。我们已经组建了一个协同调查小组， 创新和多学科的方法来测试这一假设，并将验证膨胀1通道作为一个 通过遗传（目的1）、机制（目的2）和药理学（目的3）为神经性疼痛提供新靶点 问题研究我们的研究将产生重要的知识，验证和潜在的翻译新的膨胀1- 神经性疼痛治疗的靶向疗法，并避免阿片类药物的陷阱。