Capsaicin Receptor Subtypes in Pain Transduction

疼痛传导中的辣椒素受体亚型

• 批准号: 6876643
• 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 2007-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6876643
• 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） 治疗急性和慢性疼痛，目前的治疗方法仍然与 严重的副作用包括中枢神经系统抑郁， 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神经来维持的。 神经元，选择性阻断痛觉神经末梢可以代表 一种治疗疼痛的新方法，副作用更少。最新进展 已经在受体和离子通道的表征中取得了进展， 检测疼痛性有害刺激的功能。值得注意的是，香草素（辣椒素） 受体VR 1已被分离出来，并正在进行激烈的表征， 确定它是否可以直接刺激感觉神经， 刺激。由于感觉神经元的反应特性是复杂的，我们 已经研究了是否存在其他相关的受体/离子通道， 感觉神经元这项工作揭示了辣椒素受体的存在， 剪接变体。VR.5 'sv就是我们分离出来的一个变种， 对辣椒素和其他有害刺激不敏感。在本提案中，我们 检验VR.5 ′ sv可以阻断VR 1的激活作为应答的假设 当两种蛋白质同时表达时，另一种香草素 受体剪接变体最初由另一个实验室在肾脏中鉴定 被发现具有机械敏感特性，因此被称为“拉伸 未激活的通道。“SIC是由细胞收缩激活的，基于其 在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VR 1和VR.5 'sv的比较 揭示了一种独特的结构特征，可以帮助解释它的能力， 将细胞形状的变化与通道激活结合起来。我们建议研究这个问题 功能，希望更好地了解有害的机械刺激是如何 被感觉神经元检测到。虽然我们对VR 1及其 尽管剪接变异体不断增长，但人们对是什么因素控制它们的生长却知之甚少。 丰富的感觉神经末梢。使用分离的基因组片段 在香草素受体基因的上游并插入报告质粒， 我们将检验组织衍生生长因子 调节感觉神经元中编码VR 1的RNA的量， 关于RNA转录。此外，使用该分析系统，我们希望确定 一般来说，什么因素调节VR 1、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一个 调节疼痛传导和痛觉过敏的潜在手段。