Mechanisms of Hormonal Regulation of the Sodium Chloride Cotransporter

氯化钠协同转运蛋白的激素调节机制

• 批准号: 8323954
• 负责人: Robert S Hoover
• 金额: $ 29.16万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-25 至 2015-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8323954
• 关键词: Alanine; Aldosterone; Angiotensin II; Animal Experimentation; Antihypertensive Agents; Blood Pressure; Calcium-Sensing Receptors; Cell Culture Techniques; Cell model; Cells; Chloride Ion; Chlorides; Data; Development; Endocytosis; Epidermal Growth Factor; Epidermal Growth Factor Receptor; Generations; Glucocorticoids; Hereditary Disease; Hormonal; Hormones; Hypertension; Immunoblotting; Immunohistochemistry; Investigation; Kidney; Knockout Mice; Knowledge; Lead; Leucine Zippers; Link; Lysine; MAP Kinase Gene; MAPK3 gene; Mammalian Cell; Mediating; Mediator of activation protein; Mitogen Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Molecular; Oxidative Stress; Pathogenesis; Pathway interactions; Pharmaceutical Preparations; Phosphorylation; Phosphotransferases; Physiological; Play; Process; Proline; Proteins; Publishing; Regulation; Risk Factors; Role; Signal Transduction; Site; Sodium; Sodium Chloride; Stimulus; Surface; Transactivation; Transgenic Mice; Transgenic Organisms; Tubular formation; Ubiquitination; Wild Type Mouse; absorption; base; biological adaptation to stress; blood pressure regulation; defined contribution; hormone regulation; human disease; in vivo; insight; mortality; public health relevance; salt balance; sodium-chloride cotransporter; thiazide

DESCRIPTION (provided by applicant): The thiazide-sensitive sodium chloride cotransporter (NCC) is one of the key determinants of salt balance and thus systemic blood pressure. However, in contrast to other important effectors of salt balance we know little about how hormonal and physiological signals alter activity of this cotransporter. Preliminary data demonstrates the role of the ERK1/2 MAPK (Extra-cellular signal-Regulated Kinases 1 and 2 Mitogen-Activated Protein Kinases) pathway in the ubiquitination and endocytosis of NCC. With-No-Lysine Kinase 1 and 4 (WNK1 and WNK4), Ste20-related proline alanine-rich kinase (SPAK) and Oxidative Stress Response-1 (OSR1) are also important regulators of NCC, and there is data that some hormones regulate NCC. However, a link between hormones and the intracellular pathways that mediate the effects of hormones on NCC has not been established. The broad hypothesis of the proposed investigation is that NCC is subject to hormonal regulation that proceeds through modulation of the kinases ERK1/2, SPAK/OSR and WNKs. Aim 1 will define the hormonal regulation of NCC through activation of ERK1/2 MAPK. ERK1/2 MAPK will be examined as a central mediator of the hormonal/physiological effects of Epidermal Growth Factor (EGF) and the Calcium-sensing Receptor (CaSR) on NCC. The mechanism of ERK1/2 activation and the roles of ubiquitination and endocytosis in this process will be thoroughly examined for each hormone, tracing a pathway from hormonal stimulus to functional effect. Aim 2 will determine the hormonal regulation of NCC by Aldosterone through ERK1/2 MAPK and SPAK/OSR and the mechanisms underlying these effects. ERK1/2 inhibition and SPAK/OSR activation by Aldosterone may lead to increased NCC activity. The role of WNKs in these pathways will be thoroughly examined. Aim 3 will determine the underlying molecular mechanisms mediating hormonal regulation of NCC by Angiotensin II. The roles of each of these kinase pathways will be examined with a particular emphasis on WNKs. Mammalian cell culture, isolated tubule microperfusion and whole animal experimentation will be utilized to examine effects at the cellular/molecular, tubular and organismal level. Knowledge of hormonal regulation of blood pressure has played a critical role in the development of new therapies to treat hypertension, the single risk factor that contributes the most to worldwide mortality. These studies will provide vital information on the regulation of this important effector of blood pressure homeostasis. PUBLIC HEALTH RELEVANCE: The sodium chloride cotransporter (NCC) is an important salt absorptive pathway in the mammalian kidney that is the site of action of one of the most effective classes of anti- hypertensive medications and plays a key role in genetic disorders of hypertension. Despite the importance of this cotransporter in human disease, we know little about its hormonal regulation. This investigation of the hormonal regulation of this key effector of blood pressure will provide invaluable insight into the pathogenesis of Hypertension.

描述（由申请人提供）：噻嗪类敏感的氯化钠协同转运蛋白（NCC）是盐平衡以及全身血压的关键决定因素之一。然而，与盐平衡的其他重要效应器相比，我们对激素和生理信号如何改变这种协同转运蛋白的活性知之甚少。初步数据证明了 ERK1/2 MAPK（细胞外信号调节激酶 1 和 2 丝裂原激活蛋白激酶）途径在 NCC 泛素化和内吞作用中的作用。无赖氨酸激酶1和4（WNK1和WNK4）、Ste20相关的富含脯氨酸丙氨酸激酶（SPAK）和氧化应激反应1（OSR1）也是NCC的重要调节因子，有数据表明一些激素调节国家癌症中心。然而，激素与介导激素对 NCC 影响的细胞内途径之间的联系尚未建立。拟议研究的广泛假设是 NCC 受到通过调节激酶 ERK1/2、SPAK/OSR 和 WNK 进行的激素调节。目标 1 将通过激活 ERK1/2 MAPK 来定义 NCC 的激素调节。 ERK1/2 MAPK 将作为表皮生长因子 (EGF) 和钙敏感受体 (CaSR) 对 NCC 的激素/生理影响的中心介质进行检查。 ERK1/2 激活机制以及泛素化和内吞作用在此过程中的作用将针对每种激素进行彻底检查，追踪从激素刺激到功能效应的途径。目标 2 将确定醛固酮通过 ERK1/2 MAPK 和 SPAK/OSR 对 NCC 的激素调节以及这些作用的机制。醛固酮抑制 ERK1/2 和激活 SPAK/OSR 可能导致 NCC 活性增加。 WNK 在这些途径中的作用将得到彻底研究。目标 3 将确定血管紧张素 II 介导 NCC 激素调节的潜在分子机制。将检查这些激酶途径中每一种的作用，并特别强调 WNK。哺乳动物细胞培养、离体肾小管微灌注和整体动物实验将用于检查细胞/分子、肾小管和有机体水平的影响。血压激素调节的知识在治疗高血压的新疗法的开发中发挥了关键作用，高血压是导致全球死亡率最高的单一危险因素。这些研究将为调节血压稳态的重要效应器提供重要信息。 公共卫生相关性：氯化钠协同转运蛋白 (NCC) 是哺乳动物肾脏中重要的盐吸收途径，是最有效的抗高血压药物之一的作用部位，在高血压遗传性疾病中发挥着关键作用。尽管这种协同转运蛋白在人类疾病中很重要，但我们对其激素调节知之甚少。对血压这一关键效应物的激素调节的研究将为高血压的发病机制提供宝贵的见解。