Evaluation of Endogenous TRP Agonists in Human Burns

内源性 TRP 激动剂在人体烧伤中的评价

• 批准号: 9178073
• 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
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-01-01 至 2018-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9178073
• 关键词: Acute; Address; Adverse effects; Afferent Neurons; Agonist; Analgesics; Arachidonic Acids; Blood capillaries; Burn injury; Chemicals; Clinical; Coupled; Cytochrome P450; Cytochromes; Data; Databases; Development; Electrophysiology (science); Enzymes; Evaluation; Family member; Gated Ion Channel; Grant; High Pressure Liquid Chromatography; Hospitalization; Human; Hyperalgesia; In Vitro; Injectable; Injection of therapeutic agent; Injury; Ion Channel Gating; Knowledge; Lead; Ligands; Light; Linoleic Acids; Lipids; Lipoxygenase; Mass Spectrum Analysis; Mechanics; Medical; National Institute of General Medical Sciences; Neurons; Nociception; Nociceptors; Oxides; Pain; Pain management; Patients; Peripheral; Persistent pain; Pharmaceutical Preparations; Pharmacology; Production; Rattus; Reporting; Research; Risk; Site; Skin; Source; Stimulus; System; TRPV1 gene; Testing; Thermal Hyperalgesias; Time; Tissues; Transcript; V1 Receptors; adverse outcome; allodynia; base; capillary; design; detector; in vitro Model; in vivo; innovation; millisecond; novel; novel therapeutic intervention; oxidized lipid; pain receptor; patch clamp; preclinical study; public health relevance; receptor; response; spontaneous pain

DESCRIPTION (provided by applicant): Burns often lead to persistent pain not well managed by available analgesics. The mechanisms of burn pain are incompletely understood. However, the 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.

描述（由申请人提供）：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这种疼痛。烧伤疼痛的机制尚不完全清楚。然而，TRPV1（瞬时受体电位 V1）受体似乎在烧伤后疼痛中起着关键作用。在我们的初步数据中，约 67% 的烧伤后热痛觉过敏可通过外周注射 TRPV1 受体拮抗剂来阻断。此外，烧伤的人类皮肤提取物通过 TRPV1 受体机制注射到大鼠体内时会产生热痛觉过敏。这些新数据表明 TRPV1 对热烧伤后损伤有显着影响。有趣的是，TRPV1 激活的精确机制仍然未知。综合证据表明，源自亚油酸或花生四烯酸的氧化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。许多脂质是通过细胞色素 P450 (CYP) 或脂氧合酶 (LOX) 等酶的作用形成的。这是特别重要的，因为 GLUE Grant 的分析表明，编码这些酶的转录本早在烧伤后 0-3 天就升高了。因此，我们提出了一个中心假设：氧化脂质是人类烧伤后酶促形成的，并通过激活 TRPV1 和/或 TRPA1 导致烧伤后疼痛。目前的目标将： 具体目标 1：识别氧化亚油酸以形成激活 TRPV1 或 TRPA1 的代谢物的酶。我们分析了 NIGMS 支持的 GLUE Grant 微阵列数据库，其中包含烧伤皮肤与对照人类皮肤的转录本，发现 CYP 和 LOX 水平显着升高，可持续长达 12 个月。该目标将使用 COS 表达系统，利用膜片钳电生理学来评估这些酶是否能够将亚油酸氧化成 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。其他研究将评估这些脂质之间可能存在的相互作用，以激活 TRP 通道。具体目标 2：识别氧化花生四烯酸形成激活 TRPV1 或 TRPA1 代谢物的酶。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。从科学的角度来看，它将 TRPV1 的关注点从瞬时热探测器扩展到热损伤后很久从烧伤皮肤中释放的氧化脂质探测器。从医学角度来看，这一假设具有创新性，因为它带来了一种治疗烧伤疼痛的全新药理学方法——通过阻断烧伤后组织释放的 TRPV1 和/或 TRPA1 活性化合物的酶促合成。本提案旨在全面测试这种关于持续性烧伤后疼痛的潜在突破性假设。