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)尽管付出了巨大努力以有效地 治疗急性和慢性疼痛，目前的治疗方法仍然与 显著的副作用包括中枢神经系统抑郁， 耐受性和成瘾风险的发展。由于大多数急性和非传染性疾病 慢性疼痛是由特定感官的持续激活来维持的 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 已经在表征受体和离子通道方面取得了进展 检测疼痛和有害刺激的功能。值得注意的是，香草素(辣椒素) 受体VR1已经被分离出来，并正在进行密集的特性鉴定 确定它是否能直接激活感觉神经对疼痛的反应 刺激物。由于感觉神经元的反应特性是复杂的，我们 是否有其他相关的受体/离子通道存在于 感觉神经元。这一努力揭示了香草素受体的存在。 剪接变体。VR.5‘SV就是我们分离到的一个这样的变种 对辣椒素和其他有害刺激不敏感。在这项提案中，我们是 验证VR.5‘SV可阻断VR1激活的假说 当两种蛋白质同时表达时，对有害刺激的反应。另一种香草型 另一个实验室最初在肾脏中发现的受体剪接变异体 被发现具有机械敏感特性，因此被称为“拉伸 SIC是由细胞收缩激活的，并且基于其 在感觉神经元中的表达模式，它可能参与检测 有害的高渗状态。SIC与VR1和VR.5‘SV HAS的比较 揭示了一个独特的结构特征，可以帮助解释它的能力 细胞形状的变化与通道激活有关。我们建议对此进行研究 功能，希望更好地了解机械刺激有多有害 由感觉神经元检测到。虽然我们对VR1及其相关基因的理解 剪接变异体已经增长，人们对控制它们的因素知之甚少 感觉神经末梢中有丰富的物质。利用分离的基因组片段 从香草素受体基因上游插入到报告质粒中， 我们将对组织衍生生长因子的假设进行积极的检验 通过它们的作用调节感觉神经元中编码VR1的RNA的数量 在RNA转录上。此外，利用这一检测系统，我们希望能够确定 一般来说，是什么因素调节VR1、VR.5‘SV和SIC。确定这些船头 增加或减少VR亚型转录的因素将提供 潜在的手段来调节疼痛传导和痛觉过敏。