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），尽管付出了强烈的努力，以有效 治疗急性和慢性疼痛，目前的疗法仍然与 重大副作用，包括中枢神经系统抑郁症， 耐受性和成瘾风险的发展。由于大多数急性和 通过持续激活专门的感觉，可以保持慢性疼痛 神经元，疼痛感应神经终端的选择性阻滞可以代表 一种新颖的方法来治疗疼痛的不必要副作用。最近的进步 已经在受体和离子通道的表征中做出了 功能可检测痛苦的有害刺激。值得注意的是，香草素（辣椒素） 受体VR1已被隔离，并且正在经历强烈的表征 确定它是否可以针对疼痛的响应引导感觉神经激活 刺激。由于感觉神经元的响应特性很复杂，我们 已经研究了其他相关受体 /离子通道是否存在 感觉神经元。这种努力揭示了香草受体的存在 剪接变体。 VR.5'SV是一种如此孤立的变体 对辣椒素和其他有害刺激不敏感。在这个建议中，我们是 测试VR.5'SV可以阻止VR1激活的假设 当两种蛋白质一起表达时，有害刺激。另一个香草片 另一个实验室最初在肾脏中鉴定出的受体剪接变体 被发现具有机械敏感性，因此被称为“拉伸” 灭活的通道。” SIC被细胞收缩激活，并基于其 感觉神经元中的表达方式可能参与检测 有害的高渗条件。 SIC与VR1和VR.5'SV的比较具有 揭示了独特的结构特征，可以帮助解释其能力 几对细胞形状变为通道激活。我们建议研究这一点 希望更好地了解有害机械刺激的功能 通过感觉神经元检测。尽管我们对VR1及其的理解 剪接变体已经成长，对哪些因素控制他们 感觉神经末端的丰度。使用分离的基因组片段 香草素受体基因上游，并插入报告基因质粒， 我们将测试组织衍生生长因子的假设 通过其作用调节感觉神经元中编码VR1的RNA量 在RNA转录上。此外，使用此测定系统，我们希望确定 通常，哪些因素调节VR1，VR.5'SV和SIC。确定这些弓 因素增加或减少VR子类型的转录将提供 调节疼痛转导和痛觉过敏的潜在手段。