Neuropeptidergic Inhibition of Spinal Pain Transmission

神经肽能抑制脊髓疼痛的传播

基本信息

批准号：
10063565
负责人：
BRADLEY K. TAYLOR
金额：
$ 45.13万
依托单位：
UNIVERSITY OF PITTSBURGH AT PITTSBURGH
依托单位国家：
美国
项目类别：
财政年份：
2002
资助国家：
美国
起止时间：
2002-09-10 至 2021-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10063565
关键词：
AMPA Receptors Absence of pain sensation Action Potentials Acute Address Adenylate Cyclase Affect Afferent Neurons Agonist American Analgesics Biological Assay Books Chronic Chronic inflammatory pain Confocal Microscopy Cyclic AMP Cyclic AMP-Dependent Protein Kinases Data Disease remission Electric Stimulation Electrophysiology (science)Evoked Potentials Failure Fiber Frequencies Funding Fura-2 Genetic Goals Hyperalgesia Image Immunohistochemistry In Situ Inflammation Injury Interneurons Intrathecal Injections Label Lasers Left Mediating Methods Molecular Mus N-Methyl-D-Aspartate Receptors N-Methylaspartate Neurons Neuropeptide Y Receptor Neurotoxins Nociceptors Pain Peripheral nerve injury Persistent pain Pharmacology Physical Function Physiologic pulse Posterior Horn Cells Productivity Proteins Public Health Publishing Quality of life Receptor Activation Receptor Signaling Reporting Research Signal Transduction Site Slice Spinal Spinal Cord Spine pain Stimulus Synapses TRPV1 gene Testing Traumatic injury Work central sensitization chronic pain cost dorsal horn excitatory neuron in vivo inhibitor/antagonist knock-down mental function nerve injury neuropeptide Y neuropeptide Y-Y1 receptor novel pain chronification pain relief painful neuropathy patch clamp prevent public health relevance receptor receptor internalization response small molecule inhibitor somatosensory spinal nerve posterior root synaptic inhibition tissue injury transmission process

项目摘要

Nerve injury dramatically increases NPY expression in sensory neurons and NPY receptor-mediated analgesia, yet this is underappreciated as a potential pain relief mechanism that might prevent the transition from acute to chronic pain. Among 35 original research articles, reviews, and a book published during the previous funding cycle (28 as first or senior authors), our work published in PNAS discovered that intrathecal NPY receptor antagonists or conditional genetic NPY depletion reinstated hyperalgesia, even when applied months after nerve injury or inflammation. Our overall hypothesis is that injury induces a sustained release of NPY and activation of NPY Y1 receptor signaling that opposes the transition to a chronic state of lasting pain vulnerability. However, whether tissue- or nerve-injury induced increases in spinal NPY Y1 receptor (Y1R) signaling is associated with a tonic increase in the releasable pool of NPY has been difficult to determine. To address this gap, we developed a new in situ assay of functional NPY release (Y1R internalization). Our new data indicate that Y1R internalization is greater with nerve injury after high frequency electrical stimulation of dorsal horn slices or after in vivo non-noxious stimulation of the hindpaw. Specific Aim 1 will use this novel method to test the hypothesis that non-noxious stimulus-evoked release of NPY from A-fibers will remain primed for weeks and even months after nerve injury. We now report that NPY produces an outward current and inhibits action potentials evoked by dorsal root stimulation (DRS) in Y1-EGFP labeled neurons. To test the hypothesis that injury increases synaptic inhibition by NPY, Specific Aim 2A will patch-clamp lamina II neurons and conduct Fura-2 [Ca2+]i imaging at peak of hyperalgesia after injury. We predict that Y1R agonists will inhibit stimulus-evoked responses and their concentration-response curves will be left-shifted by injury. Our progress with NPY saporin-conjugated neurotoxin indicates that Y1R-expressing dorsal horn neurons contribute to neuropathic pain, and new double-label immunohistochemistry and patch-clamp electrophysiology data in Y1R-EGFP mice support the concept that Y1R-positive neurons are excitatory. To test the hypothesis that Y1R-expressing neurons maintain LS after inflammation or nerve injury, but are held in check by NPY, Specific Aim 2B will evaluate the effects of Y1 receptor antagonists on [Ca2+]i mobilization and NMDA or AMPA receptor currents in Y1R-expressing neurons upon dorsal root stimulation or laser-directed NMDA/AMPA uncaging. Specific Aim 3 will then use an intrathecal pharmacology approach to determine whether NPY silences pronociceptive GluN AC1 Epac signaling on Y1R-expressing dorsal horn neurons and TRPA1 TRPV1 signaling on central afferents terminals. Completion of this project will bring us closer to our long-term goal of alleviating chronic pain by either: a) facilitating endogenous NPY analgesia, thus restricting pain within a state of remission; or b) extinguishing spinal neuron sensitization altogether, for example with a selective AC1 or Epac1 inhibitor.

神经损伤显着增加了感觉神经元和NPY受体介导的NPY表达镇痛，但这被认为可能是一种潜在的缓解疼痛机制，可能可能阻止过渡从急性到慢性疼痛。以前的资金周期（28名作为第一或高级作者），我们在PNAS上发表的作品发现了HATHECAL NPY受体拮抗剂或条件遗传NPY耗尽的痛觉过敏，即使应用神经损伤或炎症几个月。 NPY和NPY Y1受体信号的激活反对过渡到持续疼痛的慢性状态然而信号与NPY的释放库中的滋补相关，很难确定。解决这个差距，介绍了功能性NPY释放的新原位测定法（Y1R内部化）数据表明，Y1R与神经损伤Anjury anjury anjury anjury anjury aljury allectrical刺激相关背喇叭缝或在体内对后爪刺激。测试假说，即从A纤维中脱离NPY释放的假设将保持神经损伤后几周甚至几个月并抑制Y1 egfeled神经元中背根站（DRS）引起的动作电位假设增加了NPY的突触吸入，具体AIM 2A将贴上夹具板层II 神经元和Fura-2 [Ca2+] I受伤后的峰值峰值。将抑制刺激诱发的反应，其浓度 - 响应曲线将因受伤而移动。 NPY NPY NPY连接神经毒素的进展表明表达Y1R的背角神经元有助于神经性疼痛以及新的双标签免疫组织化学和斑块钳 Y1R-EGFP小鼠中的电生理数据支持Y1R阳性神经元的兴奋性检验以下假设，即表达Y1R的神经元在炎症或神经损伤后保持LS 由NPY检查，特定的目标2B，并评估Y1受体拮抗剂对[Ca2+] I动员和背根刺激或激光导向Y1R表达神经元中的NMDA或AMPA受体电流 NMDA/AMPA不衰老。 npy静音pronocateptivee glun是否ac1 ac1 ia 和TRPA1TRPV1信号传导该项目的组成。我们通过两者减轻疼痛的长期目标：a）促进内源性NPY镇痛，因此限制缓解疼痛的缓解状态具有选择性AC1或EPAC1抑制剂的示例。