Capsaicin Receptor Subtypes in Pain Transduction

疼痛传导中的辣椒素受体亚型

• 批准号: 6730571
• 负责人: MARK A SCHUMACHER
• 金额: $ 28.79万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-04-01 至 2006-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6730571
• 关键词: SDS polyacrylamide gel electrophoresis; Xenopus oocyte; afferent nerve; capsaicin; drug receptors; genetic promoter element; genetic transcription; genome; heat stimulus; hyperalgesia; in situ hybridization; inflammation; laboratory rat; lipoxygenase; nerve growth factors; neural transmission; neurons; nociceptors; pain; polymerase chain reaction; protein structure function; receptor expression; tissue /cell culture; voltage /patch clamp; western blottings

DESCRIPTION (provided by applicant) Despite intense efforts to effectively treat acute and chronic pain, current therapies are still associated with significant side effects including central nervous system depression, development of tolerance and risk of addiction. Since the majority of acute and chronic pain is maintained by the persistent activation of specialized sensory neurons, the selective blockade of pain sensing nerve terminals could represent a novel way to treat pain with fewer unwanted side effects. Recent advances have been made in the characterization of receptors and ion channels that function to detect painful noxious stimuli. Notably, the vanilloid (capsaicin) receptorVR1 has been isolated and is undergoing intense characterization to determine whether it can direct sensory nerve activation in response to painful stimuli. Because the response properties of sensory neurons are complex, we have investigated whether other related receptor / ion channels exist in sensory neurons. This effort has revealed the existence of vanilloid receptor splice variants. VR.5'sv is one such variant that we isolated that appears insensitive to capsaicin and other noxious stimuli. In this proposal, we are testing the hypothesis that VR.5'sv can block the activation of VR1 in response to noxious stimuli when both proteins are expressed together. Another vanilloid receptor splice variant originally identified in kidney by another laboratory was found to have mechano-sensitive properties and therefore is termed "stretch inactivated channel." SIC is activated by cell shrinkage, and based on its pattern of expression in sensory neurons, it may participate in the detection of noxious hypertonic conditions. Comparison of SIC to VR1 and VR.5'sv has revealed a unique structural feature that could help explain its ability to couple changes in cell shape into channel activation. We propose to study this feature in the hope to better understand how noxious mechanical stimuli are detected by sensory neurons. Although our understanding about VR1 and its splice variants have grown, little is known about what factors control their abundance in the sensory nerve terminals. Using genomic fragments isolated upstream from the vanilloid receptor gene and inserted into reporter plasmids, we will test the hypothesis that tissue derived growth factors positively regulate the amount of RNA encoding VR1 in sensory neurons through their effect on RNA transcription. Moreover, using this assay system, we hope to determine in general what factors regulate VR1, VR.5' sv and SIC. Determining bow these factors increase or decrease the transcription of VR subtypes will provide a potential means to modulate pain transduction and hyperalgesia.

描述（由申请人提供）尽管付出了巨大努力，有效地 治疗急性和慢性疼痛，目前的疗法仍然与 显着的副作用，包括中枢神经系统抑制， 耐受性的发展和成瘾的风险。由于大多数急性和 慢性疼痛是通过持续激活专门的感觉来维持的 神经元，选择性阻断疼痛感觉神经末梢可以代表 一种治疗疼痛的新方法，副作用较少。最新进展 已对受体和离子通道进行了表征 检测痛苦的有害刺激的功能。值得注意的是，香草酸（辣椒素） 受体VR1已被分离并正在进行深入的表征 确定它是否可以指导感觉神经激活以应对疼痛 刺激。由于感觉神经元的反应特性很复杂，我们 研究了是否存在其他相关受体/离子通道 感觉神经元。这项工作揭示了香草酸受体的存在 剪接变体。 VR.5'sv 就是我们分离出的这样一种变体 对辣椒素和其他有害刺激不敏感。在这个提案中，我们 测试 VR.5 的 v 可以阻止 VR1 的激活作为响应的假设 当两种蛋白质同时表达时，会产生有害刺激。另一种香草精 最初由另一个实验室在肾脏中发现的受体剪接变体 被发现具有机械敏感特性，因此被称为“拉伸 失活通道。”SIC 通过细胞收缩而被激活，并基于其 感觉神经元的表达模式，它可能参与检测 有害的高渗状态。 SIC与VR1和VR.5的v的比较有 揭示了一种独特的结构特征，有助于解释其能力 将细胞形状的变化耦合到通道激活中。我们建议研究这个 希望更好地了解机械刺激的有害程度 由感觉神经元检测到。虽然我们对VR1及其的了解 剪接变体已经增长，但人们对控制它们的因素知之甚少 感觉神经末梢丰富。使用分离的基因组片段 香草素受体基因上游并插入报告质粒中， 我们将检验组织衍生生长因子积极的假设 通过其作用调节感觉神经元中编码 VR1 的 RNA 数量 关于RNA转录。此外，使用该测定系统，我们希望确定 一般来说，哪些因素调节 VR1、VR.5' sv 和 SIC。确定弓这些 增加或减少 VR 亚型转录的因素将提供 调节疼痛传导和痛觉过敏的潜在手段。