Evaluation of Endogenous TRP Agonists in Human Burns

内源性 TRP 激动剂在人体烧伤中的评价

基本信息

批准号：
8631316
负责人：
Kenneth M Hargreaves
金额：
$ 29.53万
依托单位：
UNIVERSITY OF TEXAS HLTH SCIENCE CENTER
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-01-01 至 2017-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8631316
关键词：
Acute Address Adverse effects Afferent Neurons Agonist Analgesics Arachidonic Acids Blood capillaries Burn injury Burning Pain Chemicals Clinical Coupled Cytochrome P450 Cytochromes Data Databases Development Electrophysiology (science)Enzymes Evaluation Family member Figs - dietary Gated Ion Channel Grant Heating High Pressure Liquid Chromatography Hospitalization Human Hyperalgesia In Vitro Injection of therapeutic agent Injury Knowledge Lead Ligands Light Linoleic Acids Lipids Lipoxygenase Mechanics Medical National Institute of General Medical Sciences Neurons Nociception Nociceptors Pain Pain management Patients Peripheral Persistent pain Pharmaceutical Preparations Production Rattus Reporting Research Risk Site Skin Source Stimulus System Testing Thermal Hyperalgesias Time Tissues Transcript V1 Receptors adverse outcome allodynia base capillary design detector in vitro Model in vivo innovation liquid chromatography mass spectrometry millisecond novel novel therapeutic intervention oxidized lipid pain receptor patch clamp preclinical study public health relevance receptor response spontaneous pain

项目摘要

Abstract: Evaluation of Endogenous TRP Agonists in Human Burns Burns often lead to persistent pain not well managed by available analgesics. The mechanisms of burn pain are incompletely understood. However, t h e TRPV1 (transient receptor potential V1) receptor appears to be pivotally involved in post-burn pain. In our preliminary data, ~67% of post-burn thermal hyperalgesia is blocked by peripheral injection of a TRPV1 receptor antagonist. In addition, extracts of burned human skin produce thermal hyperalgesia when injected into rats via a TRPV1 receptor mechanism. These novel data suggest that TRPV1 significantly contributes to post-thermal burn injuries. Interestingly, the precise mechanism(s) for the activation of TRPV1 remains unknown. Converging evidence indicates that oxidized lipids derived from linoleic or arachidonic acid are released during tissue injury and activate TRPV1 and/or TRPA1, resulting in nociceptor depolarization and pain. Many of these lipids are formed by the actions of enzymes such as cytochrome P450s (CYP) or lipoxygenase (LOX). This is of particular significance since analysis of the GLUE Grant indicates that transcripts encoding these enzymes are elevated as early as 0-3 days after burns. Therefore, we propose the central hypothesis that oxidized lipids are enzymatically formed after human burn injuries and contribute to post-burn pain by activation of TRPV1 and/or TRPA1. The present Aims will: Specific Aim 1: Identify enzymes that oxidize linoleic acid to form metabolites that activate TRPV1 or TRPA1. We have analyzed the NIGMS-supported GLUE Grant microarray database of transcripts from skin with burn injury vs. control human skin and found significantly elevated levels of CYPs and LOXs that persist for up to 12 months. This Aim will use a COS expression system to evaluate whether these enzymes are capable of oxidizing linoleic acid into TRPV1 or TRPA1 agonists using patch clamp electrophysiology and determine the functional activity of these compounds in preclinical studies. Additional studies will evaluate possible entourage interactions among these lipids for activating TRP channels. Specific Aim 2: Identify enzymes that oxidize arachidonic acid to form metabolites that activate TRPV1 or TRPA1. Aim 2 will use the same approach as Aim 1, but will focus on arachidonic acid metabolites. This novel hypothesis has strong scientific and medical implications. From a scientific perspective, it expands the focus of TRPV1 from being a detector of transient heat, to a detector of oxidized lipids released from burned skin long after the heat-induced injury. From a medical perspective, this hypothesis is innovative since it leads to a fundamentally new pharmacological approach for treating burn pain - by blocking the enzymatic synthesis of TRPV1- and/or TRPA1-active compounds released from tissues after burns. The present proposal is designed to comprehensively test this potentially ground-breaking hypothesis of persistent post-burn pain.

摘要：内源性 TRP 激动剂在人体烧伤中的评价烧伤通常会导致持续性疼痛，而现有的镇痛药无法很好地控制疼痛。烧伤的机制痛苦不完全被理解。然而，TRPV1（瞬时受体电位V1）受体出现关键参与烧伤后疼痛。根据我们的初步数据，约 67% 的烧伤后热痛觉过敏是通过外周注射 TRPV1 受体拮抗剂来阻断。此外，烧伤的人体皮肤的提取物通过 TRPV1 受体机制注射到大鼠体内时会产生热痛觉过敏。这些新颖的数据表明 TRPV1 对热烧伤后损伤有显着影响。有趣的是，精确的 TRPV1 的激活机制仍不清楚。综合证据表明，氧化源自亚油酸或花生四烯酸的脂质在组织损伤期间释放并激活 TRPV1 和/或 TRPA1，导致伤害感受器去极化和疼痛。许多这些脂质是通过以下作用形成的酶，例如细胞色素 P450 (CYP) 或脂氧合酶 (LOX)。这具有特别重要的意义，因为 GLUE Grant 的分析表明，编码这些酶的转录本早在 0-3 就升高了烧伤后几天。因此，我们提出了一个中心假设：氧化脂质是通过酶促作用产生的。人类烧伤后形成，并通过激活 TRPV1 和/或导致烧伤后疼痛 TRPA1。目前的目标将：具体目标 1：鉴定氧化亚油酸形成激活 TRPV1 或 TRPA1 代谢物的酶。我们分析了 NIGMS 支持的 GLUE Grant 微阵列数据库，其中包含烧伤皮肤的转录本与对照人体皮肤相比，损伤后发现 CYP 和 LOX 水平显着升高，持续时间长达 12 几个月。该目标将使用 COS 表达系统来评估这些酶是否能够使用膜片钳电生理学将亚油酸氧化成 TRPV1 或 TRPA1 激动剂，并确定这些化合物在临床前研究中的功能活性。额外的研究将评估可能的随行人员这些脂质之间的相互作用激活 TRP 通道。具体目标 2：识别氧化花生四烯酸以形成激活 TRPV1 或的代谢物的酶 TRPA1。目标 2 将使用与目标 1 相同的方法，但将重点关注花生四烯酸代谢物。这一新颖的假设具有很强的科学和医学意义。从科学角度来说，它扩展了 TRPV1 的重点从瞬态热检测器转变为氧化脂质检测器热损伤后很长时间内就会烧伤皮肤。从医学角度来看，这个假设是创新的，因为它带来了一种治疗烧伤疼痛的全新药理学方法——通过阻断酶烧伤后组织释放的 TRPV1 和/或 TRPA1 活性化合物的合成。目前的建议旨在全面测试这种关于持续烧伤后疼痛的潜在突破性假设。