Convergence of the COX-2 and 5-lipoxygenase pathways

COX-2 和 5-脂氧合酶途径的融合

• 批准号: 7541465
• 负责人: Claus Schneider
• 金额: $ 29.17万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-01-01 至 2011-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7541465
• 关键词: Active Sites; Anabolism; Anti-Inflammatory Agents; Anti-inflammatory; Arachidonate 5-Lipoxygenase; Arachidonic Acids; Arterial Fatty Streak; Aspirin; Asthma; Atherosclerosis; Attenuated; Binding; Binding Sites; Biological Process; Biology; Carbon; Cells; Commit; DNA Sequence Rearrangement; Detection; Dinoprostone; Disease; Eicosanoids; Endothelial Cells; Enzymatic Biochemistry; Enzymes; Etiology; Family; Genetic Crossing Over; Human; Hydrogen Peroxide; Hydroxyeicosatetraenoic Acids; Inflammation; Inflammatory; Inflammatory Response; Interleukin-8; Isoenzymes; Kinetics; Lead; Leukotriene A4; Leukotrienes; Light; Link; Lipoxins; Lipoxygenase; Lung; Malignant Neoplasms; Mediating; Mediator of activation protein; Metabolism; Mus; Pathway interactions; Peritoneal Macrophages; Peroxides; Pharmaceutical Preparations; Property; Prostaglandin D2; Prostaglandin H2; Prostaglandin-Endoperoxide Synthase; Prostaglandins; Psoriasis; Reaction; Regulation; Resolution; Route; Series; Signal Pathway; Single Parent; Substrate Specificity; Testing; Tissues; Treatment Protocols; analog; angiogenesis; arachidonic acid 5-hydroperoxide; base; cancer type; cyclooxygenase 1; cyclooxygenase 2; macrophage; mast cell; novel; novel therapeutics

There is strong evidence for the induction of the inflammatory enzymes 5-lipoxygenase (5-LOX) and cyclooxygenase-2 (COX-2) in atherosclerosis, asthma, and many types of cancer. Both enzymes mediate the inflammatory response of these diseases through the synthesis of leukotrienes and prostaglandins, respectively. The leukotriene and prostaglandin pathways have traditionally been viewed as independent biosynthetic routes since the committed step toward either pathway is taken as the initial oxygenation of the common substrate, arachidonic acid. This proposal is based on the finding that the 5-LOX product, 5S- hydroxyeicosatetraenoic acid (5S-HETE), is a selective and highly efficient substrate for oxygenation by COX-2 (but not by the COX-1 isozyme). The discovery of this novel substrate for COX-2 intimately links the two eicosanoid pathways. The common 5-LOX/COX-2 product is a novel di-endoperoxide that is structurally reminiscent of, but distinctly different from prostaglandin H2. In the first Specific Aim we propose to analyze the enzymology of the conversion of arachidonic acid into the novel di-endoperoxide by establishing the reaction kinetics, substrate specificity, and the structural basis for binding of 5-HETE in the COX-2 active site. The enzymatic transformation of the di-endoperoxide product will be studied using RAW264.7 cells and murine peritoneal macrophages, prototypical cells that expresses both 5-LOX and COX-2. Endogenous formation of the novel eicosanoid and its family of metabolites will be assessed in mouse atherosclerotic tissue. We will test the hypothesis that the novel di-endoperoxide (or its metabolites) possess anti- inflammatory properties. Preliminary studies have shown that the di-endoperoxide attenuates the release of interleukin-8 from stimulated mast cells and microvascular endothelial cells. The signaling pathways involved in this interaction will be studied using the 5-LOX and COX-2 expressing HMC-1 human mast cell. Characterization of the novel 5-LOX/COX-2 cross-over pathway will undoubtedly lead to an entirely new understanding of the biology of 5-LOX and COX-2, and it will also shed new light on the etiology and regulation of the inflammatory component of diseases like atherosclerosis, asthma, and cancer. These studies could ultimately lead to new therapeutic regimens for the treatment of these diseases using established anti-inflammatory medications.

有充分的证据表明诱导炎性酶5-脂氧合酶（5-lox）和 动脉粥样硬化，哮喘和多种类型的癌症中的环氧合酶-2（COX-2）。两种酶都介导 这些疾病的炎症反应通过白细胞和前列腺素的合成， 分别。传统上，白细胞和前列腺素途径被视为独立 生物合成路线以来，朝着任一途径的迈出的步骤作为初始氧合 常见的底物，花生四烯酸。该提案基于5s- lox产品5s-的发现 羟基乙酸烯酸（5S-HETE）是一种选择性且高效的底物，可用于氧合作用。 COX-2（但不是由Cox-1同工酶）。发现COX-2的新颖底物的发现与 两种类类途径。常见的5-lox/cox-2产品是一种新型的Di-endoporoxide，在结构上是 让人联想到，但与前列腺素H2不同。在第一个特定目的中，我们建议分析 蛛网膜酸转化为新型二户氧化物的酶学，通过建立 反应动力学，底物特异性和COX-2活性中5-HETE结合的结构基础 地点。将使用RAW264.7细胞和 鼠腹膜巨噬细胞，表达5-lox和Cox-2的原型细胞。内源性 在小鼠动脉粥样硬化中，将评估新颖的eicosanoid及其代谢产物家族的形成 组织。我们将检验以下假设，即新型二甲氧化物（或其代谢产物）具有抗 - 炎症特性。初步研究表明，Di-耐氧化物会减弱释放 来自刺激的肥大细胞和微血管内皮细胞的白介素-8。信号通路涉及 在这种相互作用中，将使用表达HMC-1人肥大细胞的5-Lox和Cox-2进行研究。 小说5-lox/cox-2交叉途径的表征无疑会导致全新 了解5-Lox和Cox-2的生物学，这也将使病因学和 调节动脉粥样硬化，哮喘和癌症等疾病的炎症成分。这些 研究最终可能导致新的治疗方案，以治疗这些疾病 已建立的抗炎药。