Glutamate Receptor Modulation of Calcium Signaling in Neuropathic Pain

神经性疼痛中钙信号传导的谷氨酸受体调节

• 批准号: 8997069
• 负责人: Suzanne Doolen
• 金额: $ 15.6万
• 依托单位: UNIVERSITY OF KENTUCKY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-02-01 至 2019-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8997069
• 关键词: AMPA Receptors; Address; Adult; Adverse effects; Analgesics; Award; Behavior; Behavioral; CTOP; Calcium; Calcium Signaling; Cell Fractionation; Cell surface; Cells; Chemosensitization; Data; Electrophysiology (science); Fiber; Glutamate Receptor; Glutamates; Goals; Health; Healthcare; Hyperalgesia; Image; Inflammation; Inflammatory; Injury; Lead; Masks; Mediating; Membrane; Mentors; Mission; Modeling; Mus; N-Methyl-D-Aspartate Receptors; NMDA receptor antagonist; Naltrexone; Neurons; Opioid; Opioid Receptor; Pain; Pain management; Peripheral; Permeability; Phosphorylation; Receptor Activation; Receptor Signaling; Research; Research Technics; Resolution; Signal Transduction; Slice; Spinal Cord; Techniques; Testing; Western Blotting; base; career; central sensitization; chronic pain; clinically relevant; dorsal horn; endogenous opioids; inflammatory pain; innovation; mu opioid receptors; nerve injury; neuronal excitability; painful neuropathy; postsynaptic; receptor function; research study; response; sensory input; spared nerve; spinal nerve posterior root; therapeutic target; trafficking

DESCRIPTION (provided by applicant): The long term goal of this K01 career award is to understand the mechanisms that lead to injury-induced central sensitization and to establish ameliorative therapeutic targets for chronic pain. My preliminary data suggests that AMPA receptors drive glutamate-evoked Ca2+ transients in spinal cord neurons and that glutamate-evoked Ca2+ transients are potentiated following nerve injury. The central hypothesis is that nerve injury potentiates neuronal activity and Ca2+ mobilization (Aim 1), via increased GluR2 AMPA receptor phosphorylation and trafficking in the dorsal horn (Aim 2), and that this mechanism of neuropathic pain is tonically inhibited by endogenous opioids (Aim 3). This hypothesis will be tested using innovative simultaneous Ca2+ imaging and whole-cell electrophysiology to evaluate dorsal root stimulated (DRS) Ca2+ transients and neuronal activity in dorsal horn of adult spinal cord slices. Aim 1. Experiment 1a will evaluate the effect f sham or spared nerve injury (SNI) on isolated AMPA receptor Ca2+ signals and membrane currents. Experiment 1b will evaluate Ca2+ mobilization and membrane currents DRS at A¿, A¿ and c-fiber activation strength. Aim 2 While AMPA GluR2 phosphorylation and trafficking have been implicated in inflammatory pain, the mechanisms that mediate nerve injury-induced potentiation of Ca2+ levels are not known. To address this question, Experiment 2a will determine levels and subcellular localization of total and phosphorylated GluR2 in dorsal horn. Based on studies indicating inflammation-induced GluR2 internalization is NMDA receptor-dependent, Experiment 2b will test the hypothesis that intrathecal administration of NMDA receptor antagonists will reduce nerve-injury induced phosphorylation and internalization of GluR2. Aim 3. My new data suggest that opioids tonically inhibit glutamate receptor function after inflammation and thus mask neuropathic pain. Aim 3 seeks to extend this discovery to our model of peripheral neuropathic pain. Experiment 3a will attempt to correlate Ca2+ mobilization with pain-like behavior following traditional SNI and a modified nerve injury model that resolves over 4 weeks. Establishing a decrease in Ca2+ mobilization in association with behavioral resolution will allow us to test our hypothesis in Experiment 3b. Experiment 3b will evaluate the effects of opioid receptor antagonists on: DRS-stimulated Ca2+ transients and neuronal activity, and GluR2 phosphorylation and subcellular localization. We expect that opioid receptor antagonists will increase Ca2+ mobilization, neuronal activity, GluR2 phosphorylation and shift Ca2+-impermeable GluR2 expression away from the cell surface.

描述（由申请人提供）：该 K01 职业奖的长期目标是了解导致损伤引起的中枢敏化的机制，并建立慢性疼痛的改善治疗目标。我的初步数据表明 AMPA 受体驱动谷氨酸诱发的疼痛。脊髓神经元中的 Ca2+ 瞬变以及神经损伤后谷氨酸诱发的 Ca2+ 瞬变增强 核心假设是神经损伤增强了神经元活动并增强了神经元活性。 Ca2+ 动员（目标 1），通过增加 GluR2 AMPA 受体磷酸化和背角运输（目标 2），并且这种神经性疼痛机制受到内源性阿片类药物的强直性抑制（目标 3）。该假设将使用创新的同步方法进行测试。 Ca2+ 成像和全细胞电生理学评估成人脊髓背角背根刺激 (DRS) Ca2+ 瞬变和神经元活动目标 1。实验 1a 将评估假神经损伤 (SNI) 对分离的 AMPA 受体 Ca2+ 信号和膜电流的影响，实验 1b 将评估 A¿ 处的 Ca2+ 动员和膜电流 DRS。 , A?目标 2 虽然 AMPA GluR2 磷酸化和运输与炎症性疼痛有关，但介导神经损伤诱导的 Ca2+ 水平增强的机制尚不清楚，实验 2a 将确定水平和亚细胞。总 GluR2 和磷酸化 GluR2 在背角的定位 基于表明炎症诱导的 GluR2 内化是 NMDA 受体依赖性的研究，实验 2b 将测试假设鞘内施用 NMDA 受体拮抗剂会减少神经损伤引起的 GluR2 磷酸化和内化。我的新数据表明阿片类药物会在炎症后强效抑制谷氨酸受体功能，从而掩盖神经性疼痛。目标 3 试图将这一发现扩展到以下领域。我们的周围神经性疼痛模型将尝试将 Ca2+ 动员与传统 SNI 和改良的神经损伤模型后的疼痛样行为相关联。 4 周。建立与行为消退相关的 Ca2+ 动员的减少将使我们能够检验实验 3b 中的假设。实验 3b 将评估阿片受体拮抗剂对以下方面的影响：DRS 刺激的 Ca2+ 瞬变和神经元活动，以及 GluR2 磷酸化和我们预计阿片受体拮抗剂会增加 Ca2+ 动员、神经元活性、GluR2 磷酸化并改变 Ca2+ 不可渗透性。 GluR2 表达远离细胞表面。