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)：烧伤经常导致持续性疼痛，而现有的镇痛剂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(瞬时受体潜力V1)受体似乎在烧伤后疼痛中起关键作用。在我们的初步数据中，约67%的烧伤后热痛敏被外周注射TRPV1受体拮抗剂阻断。此外，烧伤皮肤的提取物通过TRPV1受体机制注射到大鼠体内时，会产生热痛觉过敏。这些新的数据表明，TRPV1在热烧伤后损伤中起重要作用。有趣的是，TRPV1激活的确切机制(S)仍不清楚。越来越多的证据表明，亚油酸或花生四烯酸衍生的氧化脂质在组织损伤过程中释放出来，激活TRPV1和/或TRPA1，导致伤害性感受器去极化和疼痛。其中许多脂质是由细胞色素P450(CYP)或脂氧合酶(LOX)等酶作用形成的。这一点特别重要，因为对GLUE Grant的分析表明，编码这些酶的转录本最早在烧伤后0-3天就会升高。因此，我们提出了一个中心假设，即氧化脂质是在人类烧伤后以酶促方式形成的，并通过激活TRPV1和/或TRPA1而导致烧伤后疼痛。目前的目标将是：具体目标1：确定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Gue Grant微阵列数据库，该数据库记录了烧伤皮肤和对照皮肤的转录结果，发现Cyps和LOX水平显著升高，持续时间长达12个月。这一目标将使用COS表达系统来评估这些酶是否能够利用膜片钳电生理将亚油酸氧化成TRPV1或TRPA1激动剂，并在临床前研究中确定这些化合物的功能活性。其他研究将评估这些脂类之间可能的相互作用，以激活Trp通道。具体目标2：确定氧化花生四烯酸形成能激活TRPV1或TRPA1的代谢物的酶。目标2将使用与目标1相同的方法，但将专注于花生四烯酸代谢物。这一新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的重点从瞬时热量的探测器扩展到热损伤后很长一段时间内烧伤皮肤释放的氧化脂质的探测器。从医学角度来看，这一假说是创新的，因为它为治疗烧伤疼痛带来了一种全新的药理学方法--通过阻止烧伤后组织释放的TRPV1和/或TRPA1活性化合物的酶合成。目前的建议旨在全面测试持续烧伤后疼痛这一潜在的突破性假说。