Convergence of the Cox-2 and 5-Lipoxygenase Pathways

Cox-2 和 5-脂氧合酶途径的融合

基本信息

批准号：
8501525
负责人：
Claus Schneider
金额：
$ 30.26万
依托单位：
VANDERBILT UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2007
资助国家：
美国
起止时间：
2007-01-01 至 2016-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8501525
关键词：
Accounting Address Adhesions Adverse effects Affect Anabolism Animal Model Anti-Inflammatory Agents Anti-inflammatory Arachidonate 5-Lipoxygenase Arachidonic Acids Arterial Fatty Streak Asthma Atherosclerosis Attenuated Autacoids Basophils Biochemical Biochemistry Biological Biology Cardiovascular system Cell physiology Cells Complement Coxibs Data Disease Dose Edema Eicosanoids Endothelial Cells Enzymes Event Family Funding Genetic Crossing Over Goals Human Hydroxyeicosatetraenoic Acids In Vitro Inflammation Inflammation Mediators Inflammatory Inflammatory Response Investigation LOX gene Lead Lesion Leukocytes Leukotrienes Life Lipids Lipoxins Modeling Names Non-Steroidal Anti-Inflammatory Agents PTGS2 gene Pathway interactions Peritoneal Pharmaceutical Preparations Physiological Physiological Processes Process Prostaglandins Psoriasis Receptor Activation Regulation Resolution Role Staging Testing Therapeutic Tissues analog angiogenesis atherogenesis biosynthetic product cancer type chemical synthesis cyclooxygenase 1 cyclooxygenase 2 design eosinophil fighting gastrointestinal hemiketal hydroxy fatty acid in vivo insight lipid mediator macrophage monocyte mouse model neutrophil novel novel therapeutics research study tool transcription factor

项目摘要

DESCRIPTION (provided by applicant): The families of eicosanoid lipid mediators formed during inflammation and other physiological and pathophysiological processes include the well-established prostaglandins, leukotrienes, lipoxins, and hydroxy- and epoxy-derivatives of arachidonic acid. These short-lived lipid autacoids regulate crucial steps in the onset and resolution as well as immunological processing of an inflammatory event. Prostaglandins and leukotrienes are biosynthesized via separate pathways following the initial oxygenation of arachidonic acid by either cyclooxygenase-2 (COX-2) or 5-lipoxygenase (5-LOX), respectively. Quite unexpectedly, we discovered that the 5-LOX and COX-2 enzymes could be acting in tandem resulting in the biosynthesis of previously unrecognized eicosanoids: Consecutive oxygenation of AA by 5-LOX and COX-2 gives an unstable di- endoperoxide that rearranges to two novel hemiketal eicosanoids that we named hemiketal (HK) D2 and HKE2. In preliminary experiments we have shown biosynthesis of HKD2 and HKE2 in mixtures of activated human leukocytes and their biological activity in stimulating endothelial cell tubulogenesis, two key findings that implicate the hemiketals as novel lipid autacoids in inflammation. In Specific Aim 1 we will test the hypothesis that biosynthesis of the hemiketals is regulated by endogenous w-3 analogs of 5-HETE, and that NSAIDs and COX-2 specific drugs affect hemiketal formation at lower doses than prostaglandin formation, implicating that therapeutic application of low-dose NSAIDs could affect hemiketal levels while sparing prostaglandin formation and the associated gastrointestinal or cardiovascular side-effects. We will also prepare HKD2 and HKE2 by total chemical synthesis for comprehensive analysis of their biological effects. In Specific Aim 2 we will test the hypothesis that the hemiketals are formed through transcellular biosynthesis with a 5-LOX expressing leukocyte providing the 5-HETE substrate (e.g., a neutrophil, eosinophil, or basophil) for COX-2 expressed in an activated macrophage or endothelial cell. These studies will be complemented by the quantification of hemiketals in different stages of human atherosclerotic lesions as a prototypical inflammatory disease and in two animal models of spontaneous inflammation/resolution. In Specific Aim 3 we will determine the role and mechanism of hemiketals as regulators of endothelial cell tubulogenesis, monocyte adhesion to endothelial cells, and activation of receptors and transcription factors involved in the inflammatory response. Together these experiments are designed to define the 5-LOX/COX-2 derived hemiketals as novel lipid autacoids with a functional role in the regulation of the inflammatory process. Novel therapeutic applications of available anti- inflammatory medications are imminent.

描述（由申请人提供）：在炎症和其他生理和病理生理过程期间形成的类二十烷酸脂质介质家族包括成熟的前列腺素、白三烯、脂氧素以及花生四烯酸的羟基和环氧衍生物。这些短命的脂质自体物质调节炎症事件的发生和消退以及免疫处理的关键步骤。前列腺素和白三烯分别通过环氧合酶-2 (COX-2) 或 5-脂氧合酶 (5-LOX) 对花生四烯酸进行初始氧化后，通过不同的途径生物合成。出乎意料的是，我们发现 5-LOX 和 COX-2 酶可以串联作用，导致以前未被识别的类二十烷酸的生物合成：AA 被 5-LOX 和 COX-2 连续氧化，产生不稳定的二内过氧化物，该二内过氧化物重排为我们将两种新型半缩酮类二十烷酸命名为 hemiketal (HK) D2 和 HKE2。在初步实验中，我们展示了活化的人白细胞混合物中 HKD2 和 HKE2 的生物合成及其刺激内皮细胞肾小管生成的生物活性，这两个关键发现表明半缩酮是炎症中的新型脂质自体物质。在具体目标 1 中，我们将检验以下假设：半缩酮的生物合成受 5-HETE 的内源性 w-3 类似物调节，并且 NSAID 和 COX-2 特异性药物以低于前列腺素形成的剂量影响半缩酮形成，这表明治疗应用低剂量非甾体抗炎药可能会影响半酮水平，同时避免前列腺素形成以及相关的胃肠道或心血管副作用。我们还将通过全化学合成的方法制备HKD2和HKE2，用于综合分析其生物学效应。在具体目标 2 中，我们将测试以下假设：半缩酮是通过表达 5-LOX 的白细胞跨细胞生物合成形成的，为活化的巨噬细胞中表达的 COX-2 提供 5-HETE 底物（例如，中性粒细胞、嗜酸性粒细胞或嗜碱性粒细胞）或内皮细胞。这些研究将通过对作为典型炎症性疾病的人类动脉粥样硬化病变的不同阶段以及自发炎症/消退的两种动物模型中的半缩酮进行定量来补充。在具体目标 3 中，我们将确定半缩酮作为内皮细胞管生成、单核细胞与内皮细胞粘附以及炎症反应中涉及的受体和转录因子的激活调节剂的作用和机制。这些实验旨在将 5-LOX/COX-2 衍生的半缩酮定义为新型脂质自体物质，在调节炎症过程中具有功能性作用。现有抗炎药物的新治疗应用迫在眉睫。