Cytochrome P450 Derived Eicosanoids and Inflammation

描述（由申请人提供）：炎症是一个基本过程，在人类许多疾病状态的发病机制中起着不可或缺的作用。核因子κ B（NF-？B）是通过转录激活细胞因子、趋化因子和细胞粘附分子表达的炎症反应的中心介质。因此，旨在抑制这种病理过程的新策略的鉴定提供了实质性的治疗潜力。在肝和肝外组织中，花生四烯酸被来自CYP 2 J和CYP 2C亚家族的细胞色素P450（CYP）环氧合酶氧化代谢为环氧二十碳三烯酸（Epoxyeicosatrienoic Acids，ESTs）。可溶性环氧化物水解酶（sEH）将E2迅速水解为活性较低的二羟基二十碳三烯酸（DHE 2）。花生四烯酸也可被代谢为20-羟基二十碳四烯酸（20-HETE）。来自CYP 4A和CYP 4F亚家族的羟化酶。最近的证据表明，CYP衍生的雌二醇和20-HETE分别具有抗炎和促炎作用。然而，CYP介导的类花生酸代谢对体内炎症调节的贡献尚未得到严格表征。我们推测，β-环氧合酶-和β-环氧合酶-之间的功能平衡，羟化酶介导的花生四烯酸代谢是不可或缺的NF-？B-介导的体内炎症反应，以及这种平衡的调节有利于β-环氧合酶途径提供了大量的治疗潜力。本提案的主要目的是：（1）确定炎症反应对肝脏和肝外CYP介导的类花生酸代谢的影响，（2）确定β-环氧合酶介导的EET生物合成和sEH介导的EET水解在炎症调节中的功能作用，（3）表征β-环氧合酶和β-环氧合酶的相对影响。羟化酶途径调节体内炎症反应。该项目将利用新的转基因和基因敲除小鼠和药理学工具，以操纵CYP介导的类花生酸代谢在体内，同时表征NF-？使用已建立的分子生物学和分析技术研究B介导的炎症反应。总的来说，这一系列新的实验将定义的机制的贡献，环氧合酶衍生的Ehrs和Ehrs？-羟化酶衍生的20-HETE在体内调节肝脏和肝外炎症反应，并促进开发新的抗炎策略，对人类的许多疾病状态具有潜在的治疗应用。公共卫生相关性：炎症是一个基本过程，在人类许多疾病的发病机制中起着不可或缺的作用。该研究项目的完成将确定细胞色素P450介导的类花生酸代谢对体内炎症调节的贡献，表征潜在机制，并促进旨在抑制炎症的新型治疗策略的开发。

DESCRIPTION (provided by applicant): Inflammation is a fundamental process which plays an integral role in the pathogenesis of numerous disease states in humans. Nuclear factor kappa B (NF-?B) is a central mediator of the inflammatory response via transcriptional activation of cytokine, chemokine and cellular adhesion molecule expression. Consequently, identification of novel strategies aimed at inhibition of this pathological process offers substantial therapeutic potential. Arachidonic acid is oxidatively metabolized by cytochrome P450 (CYP) epoxygenases from the CYP2J and CYP2C subfamilies to epoxyeicosatrienoic acids (EETs) in hepatic and extra-hepatic tissue. The EETs are rapidly hydrolyzed by soluble epoxide hydrolase (sEH) to less active dihydroxyeicosatrienoic acids (DHETs). Arachidonic acid is also metabolized to 20-hydroxyeicosatetraenoic acid (20-HETE) by CYP ?-hydroxylases from the CYP4A and CYP4F subfamilies. Recent evidence has demonstrated that CYP-derived EETs and 20-HETE possess anti- and pro-inflammatory effects, respectively. However, the contribution of CYP-mediated eicosanoid metabolism to the regulation of inflammation in vivo has not been rigorously characterized. We hypothesize that the functional balance between CYP epoxygenase- and CYP ?-hydroxylase-mediated arachidonic acid metabolism is integral to the regulation of NF-?B-mediated inflammatory responses in vivo, and modulation of this balance in favor of the CYP epoxygenase pathway offers substantial therapeutic potential. The primary objectives of this proposal are to: (1) define the impact of the inflammatory response on hepatic and extra-hepatic CYP-mediated eicosanoid metabolism, (2) define the functional role of CYP epoxygenase-mediated EET biosynthesis and sEH-mediated EET hydrolysis in the regulation of inflammation, and (3) characterize the relative impact of CYP epoxygenase and CYP ?-hydroxylase pathway modulation on inflammatory responses in vivo. This project will utilize novel transgenic and knock-out mice and pharmacological tools to manipulate CYP-mediated eicosanoid metabolism in vivo, while characterizing NF-?B-mediated inflammatory responses using established molecular biology and analytical techniques. Collectively, this series of novel experiments will define the mechanistic contribution of CYP epoxygenase-derived EETs and CYP ?-hydroxylase-derived 20-HETE to the regulation of hepatic and extra-hepatic inflammatory responses in vivo, and facilitate the development of new anti-inflammatory strategies with potential therapeutic application to numerous disease states in humans. PUBLIC HEALTH RELEVANCE: Inflammation is a fundamental process which plays an integral role in the pathogenesis of numerous diseases in humans. Completion of this research project will define the contribution of cytochrome P450-mediated eicosanoid metabolism to the regulation of inflammation in vivo, characterize the underlying mechanisms, and facilitate the development of novel therapeutic strategies aimed at inhibition of inflammation.