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: 8792377
• 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/8792377
• 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（由适用提供）：该K01职业奖的长期目标是了解导致受伤引起的中枢灵敏度的机制，并为慢性疼痛建立改善的治疗靶标。我的初步数据表明，AMPA接收器在脊髓神经元中驱动谷氨酸诱发的Ca2+瞬变，而谷氨酸诱发的Ca2+瞬变可能是神经损伤后的。中心假设是神经损伤潜在的神经元活性和CA2+动员（AIM 1），通过增加的GLUR2 AMPA受体磷酸化和背角中的运输（AIM 2），而这种神经性疼痛的机制通常受到原始opeo opeoids的抑制（AIM 3）。该假设将使用创新的同时CA2+成像和全细胞电生理学进行测试，以评估成人脊髓切片背侧角中的背根刺激（DRS）Ca2+瞬变和神经元活性。 AIM1。实验1A将评估对分离的AMPA受体CA2+信号和膜电流的效果F假假或避免神经损伤（SNI）。实验1B将在A，A和C纤维激活强度下评估Ca2+动员和膜电流DR。 AIM 2尽管在炎症性疼痛中实施了AMPA GLUR2磷酸化和运输，但尚不清楚介导神经损伤引起的Ca2+水平的潜力的机制。为了解决这个问题，实验2a将确定背角中总和GLUR2的水平和亚细胞定位。基于表明炎症诱导的GLUR2内在化的研究是NMDA受体依赖性的，实验2B将检验以下假设：鞘内给药NMDA受体拮抗剂将减少神经受损诱导的磷酸化和GLUR2的内在化。 AIM 3。我的新数据表明，阿片类药物通常在注射后抑制谷氨酸受体功能，从而掩盖了神经性疼痛。 AIM 3试图将这一发现扩展到我们的周围神经性疼痛模型。实验3A将尝试将CA2+动员与传统SNI后的疼痛样行为以及在4周内解决的改良神经损伤模型相关联。与行为分辨率相关的Ca2+动员减少将使我们能够在实验3B中检验假设。实验3B将评估阿片受体拮抗剂对：DRS刺激的Ca2+瞬态和神经元活性以及GlUR2磷酸化和亚细胞定位的影响。我们预计阿片类药物受体拮抗剂将增加Ca2+动员，神经元活性，Glur2磷酸化和移位Ca2+可耐耐磨的Glur2表达远离细胞表面。