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 神经性疼痛是一种令人衰弱的慢性疼痛综合症，影响约2500万美国人。估计 直接医疗保健成本的总经济负担和生产率损失为约2500亿美元。而且， 尽管长期能力较差 管理疼痛。这导致了阿片类药物过度和成瘾的危机。根据疾病预防控制中心的说法，有187人 在美国每天死于阿片类药物过量。因此，必须确定新的治疗靶标 安全的疼痛治疗而无需滥用责任。小胶质细胞症和神经炎症已成为关键驱动因素 神经性疼痛。响应周围神经损伤，脊髓中的小胶质细胞被激活，并且 发生扩散。 ATP是小胶质细胞最突出的激活剂之一。刺激 嘌呤能受体，小胶质细胞释放神经调节剂，引起脊髓神经元的敏化 电路导致慢性疼痛。尽管它在小胶质激活中的核心作用，但源和释放 ATP的机制仍然很了解，尤其是在神经损伤之后。该提议的理由 是在受伤后阻止脊髓中夸张的自分泌/旁分泌ATP的来源 一种有效的替代方案，是针对单个下游嘌呤能受体的当前策略的替代方法 神经性疼痛。体积调节的阴离子通道（VRAC）是大孔通道的成员 超家族及其通道活性在小胶质细胞中观察到，使其成为ATP的良好候选者 发布。但是，VRAC的分子身份是一个多3年以上的谜。通过基因组 - 宽RNAi屏幕，我们将Swell1（又名LRRC8A）确定为VRAC的唯一必需子单位。我们的 初步数据表明，1）依赖于swell1的VRAC直接渗透ATP，可以被激活 BV2小胶质细胞中的1-磷酸炎性介质鞘氨酸； 2）小胶质细胞特异性的Swell1淘汰赛 小鼠在慢性收缩损伤（CCI）中的脊髓中细胞外ATP的增强降低。 神经性疼痛的模型； 3）重要的是，突变小鼠还表现出脊柱小胶质细胞增多症的降低， CCI后神经元多动和神经性疼痛行为。基于这些发现，我们 假设含Swell1的VRAC从小胶质细胞中释放ATP，并介导自分泌和 旁分泌嘌呤能信号传导驱动脊柱小胶质细胞激活，神经炎症和疼痛 神经损伤后的超敏反应。我们组建了一个协同的调查人员团队，将使用 创新和多学科的方法来检验该假设，并将Swell1渠道验证为 通过遗传（AIM 1），机理（AIM 2）和药理学（AIM 3）的神经性疼痛的新靶标 研究。我们的研究将产生重要的知识，以验证和可能翻译新型Swell1-- 针对神经性疼痛治疗的疗法，避免阿片类药物的陷阱。