Role of Eicosanoids in Renal Function

肾脏在控制体液体积和组成中起关键作用，并且肾小管和/或血液动力学功能障碍是诸如高血压和糖尿病的疾病的常见特征。肾P450花生四烯酸（AA）单加氧酶生物合成羟基和环氧AA衍生物，已知调节肾小管转运和血管反应性。P450基因功能障碍的动物模型证实了这些酶的生理重要性，表征了它们的病理生理作用，并提供了对其代谢产物作用机制的见解。对人类P450的病理生理作用的研究确定了P450基因变异与高血压、肾脏疾病进展以及代谢综合征组分之间的关联。本申请提出建立在这些研究的基础上并解决：a）P450-类二十烷酸调节肾小管转运和血管反应性的机制，B）P450在人高血压和糖尿病的肾脏并发症中的作用，和c）这些病理生理作用的分子基础。为了实现这些目标，我们开发了一种多学科的方法，在细胞，器官和整个动物水平的P450亚型特异性表型的研究，在人类P450基因结构/表达和疾病的变化之间的关联分析，并为他们的代谢和功能后果的临床研究。Cyp 2c和Cyp 4a敲除小鼠将用于研究以下方面的基因依赖性变化：a）肾EET和/或20-HETE合酶表达，B）肾小管转运和/或血管反应性，和c）全身血压和肾病进展。将探索CYP 2C 8/2C 9或CYP 4A 11基因型与血压、胰岛素敏感性、尿液和血浆EET和20-HETE水平之间的关联，以确定变异等位基因、AA环氧化/羟基化与个体对饮食盐摄入量变化、利尿剂给药或过氧化物酶体增殖物激活受体（α）配体的反应之间的病理生理学相关性。我们的长期目标是从分子水平上了解P450类花生酸在肾脏生理学中的作用，其作用机制和作用部位，以及与人类疾病的相关性。这些都是发展有意义的方法所需要的：a）人类病理生理学意义的明确定义，和B）未来的药理学靶向，临床诊断和干预。

The kidney plays a key role in the control of body fluid volume and composition, and tubular and/or hemodynamic dysfunction are common features of diseases such as hypertension and diabetes. The renal P450 arachidonic acid (AA) monooxygenase biosynthesizes hydroxy- and epoxy-AA derivatives that are known to modulate tubular transport and vascular reactivity. Animal models of P450 gene dysfunction confirmed the physiological importance of these enzymes, characterized their pathophysiological roles, and provided insights into the mechanism of action of their metabolites. Studies of the pathophysiological roles of human P450s identified associations between P450 gene variants with hypertension, the progression of renal disease, and with components of metabolic syndrome. This application proposes to build upon these studies and to address: a) mechanisms by which the P450-eicosanoids regulate renal tubular transport and vascular reactivity, b) the role of P450s in human hypertension and renal complications of diabetes, and c) the molecular basis of these pathophysiological roles. To achieve these goals, we developed a multidisciplinary approach for studies of P450-isoform specific phenotypes at the cellular, organ and whole animal levels, the analysis of associations between alterations in human P450 gene structure/expression and disease, and for clinical studies of their metabolic and functional consequences. Cyp2c and Cyp4a knockout mice will be used to study gene-dependent changes in: a) renal EET and/or 20-HETE synthase expression, b) tubular transport and/or vascular reactivity, and c) systemic blood pressure and the progression of renal disease. Associations between CYP2C8/2C9 or CYP4A11 genotypes with blood pressure, insulin sensitivity, and urine and plasma EET and 20-HETE levels will be explored to define pathophysiological correlations between variant alleles, AA epoxidation/hydroxylation, and individual responses to changes in dietary salt intake, the administration of diuretics, or peroxisomal proliferator activated receptor (alpha) ligands. Our long term goals are to provide a molecular understanding of role(s) of P450 eicosanoids in renal physiological, their mechanism and site of action, and relevance to human disease. These are needed for the development of meaningful approaches for: a) the unequivocal definition of human pathophysiological significance, and b) future pharmacological targeting, and clinical diagnosis and intervention.