Selective Oxygenation of Endocannabinoids to Prostaglandins by Cyclooxygenase-2

Cyclooxygenase-2 将内源性大麻素选择性氧化为前列腺素

基本信息

批准号：
8881196
负责人：
LAWRENCE J. MARNETT
金额：
$ 34.51万
依托单位：
VANDERBILT UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
资助国家：
美国
起止时间：
至 2017-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8881196
关键词：
2-arachidonylglycerol Absence of pain sensation Acids Agonist Anabolism Analgesics Animal Model Anti-Inflammatory Agents Anti-inflammatory Arachidonic Acids Binding Biological Biology Breast Cancer Cell Cells Chronic Coxibs Drug Targeting Drug effect disorder Drug usage Endocannabinoids Enzymes Equilibrium Esters Exhibits Fatty Acids Fever Flurbiprofen Foundations Glycerol Human Hydrolase Hydrolysis Ibuprofen In Vitro Inflammation Inhibition of Cell Proliferation Instruction Investigation Laboratories MDA MB 231 Mediating Metabolism Modeling Molecular Molecular Target Monoacylglycerol Lipases Naproxen Nerve Tissue Non-Steroidal Anti-Inflammatory Agents Pain Pathway interactions Pharmaceutical Preparations Pharmacology Phospholipase Physiological Play Production Prostaglandin Production Prostaglandin Receptor Prostaglandin-Endoperoxide Synthase Prostaglandins R-flurbiprofen Research Role Signal Pathway Signal Transduction Pathway Site-Directed Mutagenesis Spinal Cord Spinal Ganglia Structure Substrate Specificity Symptoms Synthetic Prostaglandins System Toxicology X-Ray Crystallography analog anandamide base cannabinoid receptor constriction cyclooxygenase 1 cyclooxygenase 2 drug candidate drug discovery drug synthesis enantiomer ganglion cell in vivo inhibitor/antagonist insight interest lipid mediator neuroinflammation neuroprotection neurotoxicity painful neuropathy receptor tool

项目摘要

Endocannabinoids are lipid mediators that exhibit analgesic, neuroprotective, and anti-inflammatory activities through cannabinoid receptors. The two most studied endocannabinoids are derivatives of arachidonic acid (AA) - i.e., 2-arachidonoylglycerol (2-AG) and arachidonoylethanolamide (AEA). AA is a substrate for the cyclooxygenase enzymes (COX-1 and COX-2), which carry out the committed step in prostaglandin (PG) biosynthesis. We discovered that 2-AG and AEA are oxygenated by COX-2 much more efficiently than by COX-1 and, like AA, are oxygenated to intermediates that are converted into glycerol ester and ethanolamide analogs of PGs (i.e., PG-Gs and PG-EAs). These analogs exert potent biological activities that are independent of classical PG receptors. Thus, endocannabinoids may be the substrates for a COX-2-selective signal transduction pathway. Oxygenation by the COX enzymes is inhibited by nonsteroidal anti-inflammatory drugs (NSAIDs), which contributes to their pharmacological activity. Very recently, we discovered that NSAIDs which are classified as weak, reversible inhibitors of AA oxygenation are potent, poorly reversible inhibitors of 2-AG and AEA oxygenation. This "substrate-selective" inhibition provides a mechanism by which endocannabinoid metabolism through COX-2 can be inhibited without any impact on AA metabolism. Particularly exciting is our discovery that (R)-enantiomers of arylpropionic acid NSAIDs (e.g., (R)-flurbiproten), which were previously thought to be inactive against COX enzymes, are efficient inhibitors of 2-AG oxygenation by COX-2 in vitro and in cultured dorsal root ganglion cells. This finding may explain the analgesic activity of (f?)-flurbiproten in humans and in animal models of neuropathic pain. The latter has been associated with elevation of endocannabinoid levels in the spinal cord. We propose to elucidate the molecular determinants of substrate-selective inhibition of COX-2 by (R)-NSAIDs using a combination of site-directed mutagenesis, structure-activity analysis, and X-ray crystallography. We will use this information to optimize the potency and selectivity of this class of agents and evaluate the most promising compounds in dorsal root ganglion cells and the chronic constriction model of neuropathic pain. We will also identify the enzyme(s) that hydrolyze PG-Gs to PGs, thereby limiting their half-lives and biological activities. This will provide new insights into NSAID action and tools and drug candidates focused on the COX-2-endocannabinoid metabolism and signaling pathway.

内源性大麻素是通过大麻素受体表现出镇痛，神经保护性和抗炎活性的脂质介质。研究最多的内源性大麻素是花生四烯酸（AA）的衍生物 - 即2-芳基二烯丙基甘油（2-AG）和蛛网膜烯丙基甲醇酰胺（AEA）。 AA是环氧合酶（COX-1和COX-2）的底物，它在前列腺素（PG）生物合成中执行了构成的步骤。我们发现，2-AG和AEA被COX-2氧化比COX-1要高得多，并且像AA一样，将转化为PGS的甘油酯和乙醇酰胺类似物（即PG-GS和PG-SEAS和PG-AS）的中间体氧合。这些类似物具有独立于经典PG受体的有效生物学活性。因此，内源性大麻素可以是COX-2选择信号转导途径的底物。 Cox酶的氧合受到非甾体类抗炎药（NSAID）的抑制，这有助于其药理活性。最近，我们发现被归类为弱，可逆的AA氧合抑制剂的NSAIDS有效，可逆的2AG和AEA氧合抑制剂。这种“底物选择性”抑制作用提供了一种机制，可以抑制内源性大麻素代谢，而不会对AA代谢产生任何影响。我们的发现特别令人兴奋的是，芳基丙酸NSAID（例如（例如（R） - 荧光蛋白酶）以前被认为对Cox酶无活性的（例如（R） - 荧光蛋白酶）是cox-2中的2-AG氧化的有效抑制剂。这一发现可能解释了（F？） - 人类和神经性疼痛动物模型中的镇痛活性。后者与脊髓中内源性大麻素水平的升高有关。我们建议使用位置定向的诱变，结构活性分析和X射线晶体学的组合，通过（R）-NSAIDS阐明COX-2对COX-2的底物选择性抑制的分子决定因素。我们将使用此信息来优化该类别的药物的效力和选择性，并评估背根神经节细胞中最有前途的化合物和神经性疼痛的慢性收缩模型。我们还将确定将PG-GS水解为PG的酶，从而限制其半衰期和生物活性。这将为NSAID动作和工具和候选药物提供新的见解，这些作用和候选药物专注于COX-2-内源性大麻素代谢和信号传导途径。