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：
8852624
负责人：
Claus Schneider
金额：
$ 31.36万
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 2017-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8852624
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过程中形成的类花生酸脂质介质的家族包括成熟的前列腺素，白细胞素，脂氧蛋白，脂氧和羟基和羟基和环氧源性羟基氨基酸的衍生物。这些短寿命的脂质自动体调节发作和分辨率的关键步骤以及炎症事件的免疫学处理。前列腺素和白细胞分别通过环氧酶-2（COX-2）或5-脂氧合酶（5-lox）的初始氧化后，通过单独的途径生物合成。非常出乎意料的是，我们发现5-lox和Cox-2酶可能作用于串联，从而导致先前未识别的eicosanoids的生物合成：5-lox和cox-2对AA的连续氧合，从而使不稳定的二 - 内托氧化物重新排列了。我们命名为Hemiketal（HK）D2和HKE2的两个新型半蛋白酶。在初步实验中，我们已经在活化的人白细胞混合物中显示了HKD2和HKE2的生物合成及其在刺激内皮细胞肾小管生成中的生物学活性，这两个关键发现将半蛋白酶作为炎症中新型脂质型脂肪的含量。在特定目的1中，我们将测试以下假设：半蛋白质的生物合成受5-Hete的内源性W-3类似物调节，并且NSAID和COX-2特异性药物会影响比前列腺素形成的较低剂量的半剂量形成低剂量的NSAID可能会影响前列腺素的形成以及相关的胃肠道或心血管副作用。我们还将通过总化学合成来准备HKD2和HKE2，以全面分析其生物学作用。在特定目标2中，我们将测试以下假设：半蛋白酶是通过跨细胞生物合成形成的，具有5-lox表达白细胞，可提供5-HETE底物（例如，中性粒细胞，嗜酸性粒细胞或basbophil）在激活的巨噬细胞中表达的Cox-2或内皮细胞。这些研究将通过在人动脉粥样硬化病变的不同阶段定量作为一种典型的炎症性疾病以及两种自发炎症/分辨率的动物模型来补充。在特定目标3中，我们将确定半蛋白酶的作用和机制，作为内皮细胞肾小管生成的调节剂，对内皮细胞的单核细胞粘附以及受体的激活以及涉及炎症反应中涉及的转录因子。这些实验旨在将5-lox/cox-2衍生的半蛋白酶定义为新的脂质自acoids，在调节炎症过程中具有功能作用。可用的抗炎性药物的新型治疗应用是迫在眉睫的。