NADPH-DEPENDENT METABOLISM OF ARACHIDONIC ACID

细胞色素P450（P450）依赖性花生四烯酸（AA）单加氧酶， 现在被认为是生物医学重要AA的第三个分支 级联。最广泛表征的P450类花生酸，环氧- 和19/20-羟基花生四烯酸，已被牵连在控制 血管反应性、离子流、激素信号和 实验性高血压然而，由于缺乏合适的分子 这些工具的作用机制和生理意义 代谢物仍有待确定。假设是：A） 特异性P450类花生酸的细胞内生物合成提供了重要的 细胞和器官功能的脂质介质，B）氧化代谢起作用 在控制细胞/器官P450类花生酸水平中起重要作用，因此， 生物学功能和效力，和C）配体激活过氧化物酶体 增殖物激活受体α（PPARalpha）参与了 P450类花生酸和脂肪酸氧化代谢的协调调节。 由于类花生酸信息含量、信号传导特性和 生物学作用由酶、同种型特异性、区域和 AA分子模板的立体选择性氧化，该项目将 利用重组DNA、生物化学和生物分析的组合 技术：a）区域选择性AA的设计和构建 单加氧酶及其在培养细胞中的表达，B）记录 细胞P450类二十烷酸的生物合成和代谢，c）研究 cDNA依赖性细胞表型，和d）功能和生物化学 过氧化物酶体β-氧化和微粒体 omega/omega-1羟基化在P450-类二十烷酸代谢和功能中的作用。的 总体目标是提供一个生物化学和分子描述的 该途径在器官/身体生理学和/或病理生理学中的作用。 P450类二十烷酸及其对细胞和全身的作用 潜在的生物医学意义继续为 研究这种代谢途径。这些问题的实验答案 这些假设所提出的是必要的：a）明确的定义， P450 AA的生理和/或病理生理学意义 单加氧酶，和B）制定有效的战略， 药理学和/或临床干预。

The cytochrome P450 (P450)-dependent arachidonic acid (AA) monooxygenases, are now recognized as the third branch of the bio-medically important AA cascade. The most extensively characterized of the P450 eicosanoids, the epoxy- and the 19/20-hydroxy arachidonic acids, have been implicated in the control of vascular reactivity, ion fluxes, hormonal signaling and the pathophysiology of experimental hypertension. However, due to paucity of appropriate molecular tools, the mechanisms of action and physiological significance of these metabolites remains to be established. The hypotheses are that: A) the intracellular biosynthesis of specific P450 eicosanoids provides important lipid mediators of cellular and organ function, B) oxidative metabolism plays an important role in the control of cell/organ P450 eicosanoid levels and thus, biological function and potency, and C) the ligand activated peroxisomal proliferator activated receptor alpha (PPARalpha) participates in the coordinated regulation of P450 eicosanoid and fatty acid oxidative metabolism. Inasmuch as eicosanoid informational content, signaling properties, and biological role are controlled by enzymatic, isoform specific, regio-, and stereoselective oxygenations of the AA molecular template, this project will utilize combinations of recombinant DNA, biochemical, and bioanalytical techniques for: a) the design and construction of regioselective AA monooxygenases and their expression in cultured cells, b) the documentation of cellular P450 eicosanoid biosynthesis and metabolism, c) the study of cDNA-dependent cellular phenotypes, and d) the functional and biochemical analysis of the role(s) of peroxisomal beta-oxidation and microsomal omega/omega-1 hydroxylation in P450-eicosanoid metabolism and function. The overall goals are to provide a biochemical and molecular description of the role(s) of this pathway in organ/body physiology and/or pathophysiology. The documented cellular and systemic effects of the P450 eicosanoids and their potential biomedical significance continue to provide the rationale for the studies of this metabolic pathway. The experimental answers to the questions posed by these hypotheses are needed for: a) the unequivocal definition of the physiological and/or pathophysiological significance of the P450 AA monooxygenases, and b) the formulation of effective strategies for future pharmacological and/or clinical intervention.