Modulation of the renal aldosterone endothelin feedback system by the clock protein PER1

项目概述：高醛固酮水平和高盐饮食有助于高血压的流行 和肾脏疾病。这部分是由于肾脏内的液体和电解质平衡失调。的 肾脏通过其对钠（Na）的稳态控制在血压（BP）的调节中起关键作用， 以及远端肾单位的水平衡。这一过程受到盐皮质激素醛固酮的严格调控 和其他内在调节机制，包括内皮素-1（ET-1）信号轴。我们发现ET-1 作为新的醛固酮靶点。我们还证明了ET-1在细胞内的反馈机制中起作用。 肾集合管通过ETRA和ETRB受体的信号传导抑制Na重吸收。这 内在的调节机制，肾醛固酮内皮素反馈系统（RAEFS），是必需的， 正常的血压调节和钠稳态。该反馈系统的重要性由以下说明： 它的破坏，导致盐敏感性高血压和液体潴留引起的戏剧性的影响。 临床上，ETRA/B阻滞剂已显示出对肾脏疾病的疗效，但液体潴留是一种令人不安的副作用。 我们已经确定了生物钟蛋白PER 1作为血压调节和肾钠离子缺乏的关键成分。 体内平衡我们已经证明PER 1以性别特异性的方式控制Na平衡和血压， 盐敏感性高血压我们证明PER 1是ET-1表达的负调节因子， 连接PER 1和RAEFS。利用盐敏感性高血压模型，我们最近发现， 肾特异性（KS）-PER 1 KO小鼠表现出高血压和不适当的钠潴留， 盐饮食加醛固酮类似物。重要的是，KS-PER 1 KO小鼠在肿瘤组织中表现出升高的ET-1水平。 肾脏和尿液。我们最近还发现了一种新的，长的非编码RNA，它是ET-1的反义核酸。 基因，EDN 1-AS。EDN 1-AS是ET-1的正调节剂。我们的新数据表明ET-1和EDN 1-AS是 由醛固酮正调控，但由PER 1负调控。这些数据共同支持了我们的整体 假设PER 1通过抑制醛固酮增加的作用来维持血压和钠平衡， ET-1在肾脏我们建议，这种调制的RAEFS构成了一个新的范例反馈 控制钠平衡和血压。目的1将利用对照组和肾脏中的全动物BP和Na平衡研究， 特异性PER 1和ET-1 KO小鼠。目的2采用离体灌流的集合管， PER 1对ET-1依赖性肾小管钠重吸收的影响。目标3将使用一个独特的细胞模型的收集 用EDN 1-AS诱导性过表达的导管来确定PER 1、醛固酮和 EDN 1-AS调节ET-1基因。我们认为，了解ET-1的昼夜分子调控， 是解开ET受体阻滞剂相关难题的关键。完成这些研究将 提供必要的机械知识，以确定采用昼夜节律精度的可行性 盐敏感性高血压的定制治疗药物。

Project Summary: Elevated aldosterone levels and high salt diets contribute to the epidemics of hypertension and kidney disease. This is in part due to dysregulation of fluid and electrolyte balance within the kidney. The kidney plays a key role in the regulation of blood pressure (BP) through its homeostatic control of sodium (Na) and water balance by the distal nephron. This process is tightly regulated by the mineralocorticoid aldosterone and other intrinsic regulatory mechanisms, including the endothelin-1 (ET-1) signaling axis. We identified ET-1 as a novel aldosterone target. We also demonstrated that ET-1 acts in a feedback mechanism within the kidney collecting duct to inhibit Na reabsorption via signaling through both the ETRA and ETRB receptors. This intrinsic regulatory mechanism, the renal aldosterone endothelin feedback system (RAEFS), is required for normal BP regulation and Na homeostasis. The significance of this feedback system is illustrated by the dramatic effects caused by its disruption, which causes salt-sensitive hypertension and fluid retention. Clinically, ETRA/B blockers have shown efficacy in kidney disease, but fluid retention is a troubling side effect. We have identified the circadian clock protein PER1 as a critical component for BP regulation and renal Na homeostasis. We have shown that PER1 acts in a sex-specific manner to control Na balance and BP in the setting of salt-sensitive hypertension. We demonstrated that PER1 is a negative regulator of ET-1 expression, linking PER1 and the RAEFS. Using a model of salt-sensitive hypertension, we recently discovered that male kidney-specific (KS)-PER1 KO mice exhibit increased BP and inappropriate Na retention in response to a high salt diet plus an aldosterone analog. Importantly, KS-PER1 KO mice exhibit elevated levels of ET-1 in the kidney and urine. We also recently discovered a novel, long non-coding RNA that is antisense to the ET-1 gene, EDN1-AS. EDN1-AS is a positive regulator of ET-1. Our new data show that ET-1 and EDN1-AS are positively regulated by aldosterone but negatively regulated by PER1. Together these data support our overall hypothesis that PER1 maintains BP and Na balance through inhibiting the action of aldosterone to increase ET-1 in the kidney. We propose that this modulation of the RAEFS constitutes a new paradigm for feedback control of Na balance and BP. Aim 1 will utilize whole animal BP and Na balance studies in control and kidney- specific PER1 and ET-1 KO mice. Aim 2 will employ the isolated perfused collecting duct to test the effect of PER1 on ET-1-dependent renal tubular Na reabsorption. Aim 3 will use a unique cell model of the collecting duct with inducible overexpression of EDN1-AS to determine the mechanism by which PER1, aldosterone, and EDN1-AS regulate the ET-1 gene. We propose that understanding the circadian molecular regulation of ET-1 is the key to unlocking the difficulties associated with ET-receptor blockers. Completion of these studies will provide the mechanistic knowledge necessary to determine the feasibility of employing circadian precision medicine for the tailored treatment of salt-sensitive hypertension.