Characterization And Functional Significance Of P450 Ara

P450 Ara 的表征及功能意义

• 批准号: 7168262
• 负责人: Darryl C Zeldin
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF ENVIRONMENTAL HEALTH SCIENCES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7168262
• 关键词: androgens; angiotensin II; arachidonate; blood pressure; cardiovascular disorder risk; cardiovascular function; cytochrome P450; eicosanoid metabolism; enzyme activity; enzyme mechanism; epoxide hydrolase; estrogens; gel mobility shift assay; gene expression profiling; gene therapy; genetically modified animals; hormone regulation /control mechanism; human subject; ion transport; kallikreins; kidney function; laboratory mouse; pharmacogenetics; polymerase chain reaction; single nucleotide polymorphism; telemetry

Cytochromes P450 metabolize arachidonic acid (AA) to epoxyeicosatrienoic acids (EETs) which have potent effects on cardiovascular and renal function. EETs are metabolized to corresponding diols (DHETs) by soluble epoxide hydrolase (sEH). Current research involves: (1) characterization of CYP2J and CYP2C subfamily P450s at the biochemical and molecular levels; (2) evaluation of the functional roles of CYP2J products in cardiovascular and renal physiology; and (3) examination of this pathway in selected animal models of human disease (ischemic heart disease, hypertension, atherosclerosis). We have discovered a number of mammalian CYP2Js, although we have focused most of our efforts on human CYP2J2 and mouse CYP2J5. Human CYP2J2 is the major human P450 expressed in heart and vasculature, where it is localized to cardiac myocytes and endothelial cells, and is active in the metabolism of AA to EETs. CYP2J2-derived EETs are vasodilators, inhibit cytokine-induced endothelial cell adhesion molecule expression, induce tissue plasminogen activator gene expression, inhibit vascular smooth muscle cell migration, protect endothelial cells against hypoxia-reoxygenation injury, upregulate endothelial nitric oxide biosynthesis, affect cardiac electrophysiology, and protect the heart from ischemic injury. CYP2J2 transgenic mice (alpha-myosin heavy chain promoter driven cardiac-specific expression) were developed to study the effects of increased EETs on cardiac function in vivo. These mice have normal basal heart anatomy and function, improved post-ischemic left ventricular function, shortened cardiac action potential, altered cardiac electrophysiology, and enhanced beta-adrenergic receptor responsiveness. Similarly, sEH null mice which exhibit reduced EET hydrolysis have improved postischemic functional recovery. We have also developed transgenic mice in which CYP2J2 is expressed exclusively in endothelial cells (Tie2 promoter driven) to examine the role of CYP2J2 products on vascular function. The phenotype of these mice is currently being evaluated. The human CYP2J2 gene has been cloned, sequenced and characterized. We have identified several functionally relevant CYP2J2 polymorphic variants, one of which is associated with reduced CYP2J2 expression and is present at higher frequency in patients with cardiovascular disease vs. normals in a large German cohort. We have also identified functionally relevant polymorphisms in the sEH gene and have shown that they are associated with increased cardiovascular risk in a large multicenter cohort in the U.S. CYP2J5 is a major murine P450 arachidonic acid epoxygenase expressed in the kidney and localized to proximal tubules. To evaluate the role of this P450 and its eicosanoid products in renal function and blood pressure regulation, we disrupted the Cyp2j5 gene by homologous recombination. CYP2J5 null mice have spontaneous hypertension that persists on both high and low salt diets. The hypertension is much more severe in females, is associated with reduced circulating estradiol levels, and is responsive to estrogen supplementation. CYP2J5 null female mice also have increased proximal tubular transport rates, enhanced vascular responsiveness to angiotensin II and endothelin, and reduced fertility compared to wild type counterparts. This new animal model will lead to a better understanding of the complex interrelationship between renal P450s, sex hormones, renal eicosanoids and blood pressure regulation. Consistent with these findings, we have shown that there is an association between CYP2J2 polymorphic variants and hypertension in a cohort from Tennessee.

细胞色素P450代谢蛛网膜酸（AA）为环氧卫生酸（EET），对心血管和肾功能具有有效作用。 EET由可溶性环氧水解酶（SEH）代谢为相应的二醇（DHET）。当前的研究涉及：（1）在生化和分子水平上表征CYP2J和CYP2C亚家族P450； （2）评估CYP2J产品在心血管和肾脏生理学中的功能作用； （3）在选定的人类疾病动物模型（缺血性心脏病，高血压，动脉粥样硬化）中检查该途径。我们发现了许多哺乳动物CYP2J，尽管我们将大部分精力集中在人CYP2J2和小鼠CYP2J5上。人CYP2J2是在心脏和脉管系统中表达的主要人类P450，它位于心肌细胞和内皮细胞中，并且活跃于AA代谢为EET为EET的代谢。 CYP2J2衍生的EET是血管扩张剂，抑制细胞因子诱导的内皮细胞粘附分子表达，诱导组织纤溶酶原激活剂基因表达，抑制平滑肌细胞的纤维蛋白原激活剂，可保护内皮细胞免受内皮细胞的侵害，可影响低氧氧合损伤，上调氧化氧化物的氧化氧化物氧化型氧化物氧化物，促进氧化物的氧化物氧化物氧化物氧化物，促进氧化物氧化物氧化物，促进了氧化物的氧化物氧化物，可保护内皮细胞，并保护内皮氧化物氧化物氧化物氧化物氧气损伤。缺血性损伤。开发了CYP2J2转基因小鼠（α-肌球蛋白重链启动子驱动的心脏特异性表达），以研究增加Eets对体内心脏功能的影响。这些小鼠具有正常的基础心脏解剖结构和功能，缺血后左心室功能改善，心脏作用缩短，心脏电生理学改变以及增强的β-肾上腺素能受体反应性。同样，表现出降低EET水解的SEH无效小鼠也改善了缺血后的功能恢复。我们还开发了转基因小鼠，其中CYP2J2仅在内皮细胞（TIE2启动子驱动）中表达，以检查CYP2J2产物对血管功能的作用。这些小鼠的表型目前正在评估。人CYP2J2基因已被克隆，测序和表征。我们已经确定了几种与功能相关的CYP2J2多态性变体，其中一种与CYP2J2的表达降低有关，并且在大型德国人群中患有心血管疾病与正常性的患者中，在较高频率上存在。我们还鉴定了SEH基因中与功能相关的多态性，并表明它们与美国大型多中心队列中的心血管风险增加有关，CYP2J5是一种主要的鼠P450鼠蛛网膜酸环氧酶，在肾脏中表达，并局部化，并局部用于邻近的小节型小管。为了评估该p450及其类黄酮产物在肾功能和血压调节中的作用，我们通过同源重组破坏了CYP2J5基因。 CYP2J5无效小鼠的自发性高血压持续在高盐饮食和低盐饮食上。女性中的高血压更为严重，与循环雌二醇水平降低有关，并且对补充雌激素的反应有反应。 CYP2J5无效的雌性小鼠还具有近端管状转运率，对血管紧张素II和内皮素的血管反应增强，与野生型对应物相比，生育力降低。这种新的动物模型将更好地理解肾脏P450，性激素，肾类花生酸和血压调节之间的复杂相互关系。与这些发现一致，我们已经表明，田纳西州的同伴中CYP2J2多态性变体与高血压之间存在关联。