Molecular Determinants of Synaptic Plasticity in Chronic Pain

慢性疼痛突触可塑性的分子决定因素

• 批准号: 10589545
• 负责人: Shao-Rui Chen
• 金额: $ 50.21万
• 依托单位: UNIVERSITY OF TX MD ANDERSON CAN CTR
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-15 至 2027-11-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10589545
• 关键词: Afferent Neurons; Anions; Behavioral; Biochemical; C-terminal; Cations; Cell Size; Cell Volumes; Clinical; Data; Development; Down-Regulation; Family member; Gene Delivery; Glutamate Receptor; Glutamates; Goals; Hypersensitivity; In Vitro; Knowledge; Leucine-Rich Repeat; Link; Mediating; Molecular; N-Methyl-D-Aspartate Receptors; Neuronal Plasticity; Neurons; Neuropathy; Nociception; Paclitaxel; Pain; Phenotype; Pilot Projects; Play; Posterior Horn Cells; Proteins; Regulation; Role; Sensory; Signal Transduction; Small Interfering RNA; Spinal; Spinal Cord; Spinal Ganglia; Synapses; Synaptic plasticity; Testing; Therapeutic; Transgenic Mice; Traumatic Nerve Injury; Vertebral column; antagonist; chemotherapy; chemotherapy induced neuropathy; chronic neuropathic pain; chronic pain; chronic pain management; chronic painful condition; conditional knockout; dorsal horn; in vivo; innovation; insight; interdisciplinary approach; knock-down; nerve injury; nervous system disorder; novel; novel therapeutics; overexpression; pain chronification; pain model; painful neuropathy; presynaptic; receptor coupling; restraint; trafficking; transmission process

Molecular Determinants of Synaptic Plasticity in Chronic Pain The long-term goal of our project is to identify the molecular and signaling mechanisms that govern synaptic plasticity under chronic pain conditions. Neuropathic pain remains a major therapeutic challenge, and neuronal plasticity at the spinal cord level is fundamentally important to the development of chronic neuropathic pain. N- methyl-D-aspartate receptors (NMDARs) are expressed in primary sensory neurons and their central terminals in the spinal dorsal horn. However, they are functionally inactive under normal conditions and become tonically activated to potentiate glutamatergic input to spinal dorsal horn neurons after nerve injury and chemotherapy- induced neuropathy. The molecular mechanisms regulating the synaptic activity and trafficking of NMDARs in the spinal dorsal horn remain poorly understood. Volume-regulated anion channels, which are formed by multiple different leucine-rich repeat-containing protein 8 (LRRC8) family members, are crucial to the regulation of cell volume. In our pilot studies, we found that LRRC8A was highly expressed in dorsal root ganglion (DRG) neurons. Also, traumatic nerve injury selectively downregulated LRRC8A, but not LRRC8B-LRRC8D, in the DRG. Furthermore, LRRC8A downregulation or conditional knockout in DRG neurons induces NMDAR-dependent pain hypersensitivity. Importantly, we discovered that LRRC8A physically interacted with NMDARs to control synaptic trafficking and activity of NMDARs. In this renewal application, we will specifically determine the roles of LRRC8A in the regulation of nociception and synaptic NMDARs at the spinal cord level in two neuropathic pain models. On the basis of our intriguing preliminary data, we propose to test the overall hypothesis that LRRC8A protein directly interacts with NMDARs and normally restrains the synaptic trafficking of NMDARs at the spinal cord level; nerve injury or chemotherapy diminishes LRRC8A expression and augments the synaptic expression and activity of NMDARs, leading to increased glutamatergic input to spinal dorsal horn neurons and chronic pain. We will apply several innovative and complementary approaches, including biochemical and cellular analyses, transgenic mice, and synaptic recordings to study how LRRC8A controls NMDARs and nociception at molecular, cellular, and behavioral levels. Our project will generate fundamental new information about the molecular basis of NMDAR-mediated synaptic plasticity in neuropathic pain. Findings from our project are expected to advance our knowledge of molecular mechanisms of nociceptive regulation and to guide the development of new strategies for treating chronic neuropathic pain.

慢性疼痛中突触可塑性的分子决定因素 我们项目的长期目标是确定控制突触的分子和信号传导机制 在慢性疼痛条件下的可塑性。神经性疼痛仍然是一个主要的治疗挑战和神经元 脊髓水平的可塑性对于慢性神经性疼痛的发展至关重要。 n- 甲基-D-天冬氨酸受体（NMDAR）在主要感觉神经元及其中央末端表达 在脊髓角。但是，它们在正常条件下在功能上不活跃，并且可以进行音调 被激活以增强谷氨酸能在神经损伤和化学疗法后对脊柱背角神经元的输入 诱导神经病。调节NMDARS突触活性和贩运的分子机制 脊髓角的理解仍然很差。体积调节的阴离子通道，由多个形成 不同的富含亮氨酸的重复蛋白8（LRRC8）家族成员对细胞的调节至关重要 体积。在我们的试点研究中，我们发现LRRC8A在背根神经（DRG）神经元中高度表达。 同样，DRG中的创伤性神经损伤选择性下调LRRC8A，而不是LRRC8B-LRC8D。 此外，DRG神经元中的LRRC8A下调或条件敲除诱导NMDAR依赖性 疼痛超敏反应。重要的是，我们发现LRRC8A与NMDAR进行了物理相互作用以控制 NMDAR的突触贩运和活动。在此续订应用程序中，我们将专门确定角色 LRRC8A在两个神经性脊髓水平上的伤害感受和突触NMDAR的调节中 疼痛模型。根据我们有趣的初步数据，我们建议测试总体假设 LRRC8A蛋白直接与NMDAR相互作用，通常限制NMDARS的突触运输 脊髓水平；神经损伤或化学疗法降低LRRC8A表达并增强突触 NMDAR的表达和活性，从而导致脊柱型脊髓脊髓角神经元的输入增加 慢性疼痛。我们将采用几种创新和互补的方法，包括生化和 细胞分析，转基因小鼠和突触记录，以研究LRRC8A如何控制NMDAR和 分子，细胞和行为水平上的伤害感受。我们的项目将产生基本的新信息 关于神经性疼痛中NMDAR介导的突触可塑性的分子基础。我们项目的发现 期望提高我们对伤害性调节分子机制的了解，并指导 制定治疗慢性神经性疼痛的新策略。