Regulation of Renal Response to Vasopressin by Glycogen Synthase

糖原合酶调节肾脏对加压素的反应

基本信息

批准号：
8897355
负责人：
Reena Rao
金额：
$ 41.3万
依托单位：
UNIVERSITY OF KANSAS MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-09-20 至 2017-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8897355
关键词：
Adenylate Cyclase Amino Acids Binding Bipolar Disorder Cell Differentiation process Cells Cirrhosis Congestive Heart Failure Cyclic AMP Cyclic AMP-Dependent Protein Kinases Disease Disease Progression Duct (organ) structure Epithelial Equilibrium Experimental Water Deprivation Family Feedback Gene Deletion Generations Glycogen (Starch) Synthase Glycogen Synthase Kinase 3 Goals Homeostasis In Vitro Investigation Kidney Knockout Mice Lead Lithium Mediating Mus Nephrogenic Diabetes Insipidus Neurohormones Phosphorylation Phosphotransferases Physiological Plasma Play Polycystic Kidney Diseases Protein Isoforms Protein-Serine-Threonine Kinases Regulation Resistance Role Signal Transduction Site Site-Directed Mutagenesis Testing Vasopressins Water Wild Type Mouse analog apical membrane aquaporin-2 base in vivo inhibitor/antagonist mouse model response trafficking urinary water channel

项目摘要

DESCRIPTION (provided by applicant): Glycogen synthase kinase 3 (GSK3) is a family of serine/threonine protein kinases that consists of two isoforms, GSK3a and GSK3�. In the kidney, GSK3� is known to regulate cell differentiation and normal epithelial function. Despite in vitro and in vivo evidence that lithium, a common therapy for bipolar disorders and a potent inhibitor of GSK3� can reduce renal response to vasopressin, the role of GSK3� in renal water transport is not clear. Our observations in the lithium induced polyuric mouse model as well as collecting duct specific GSK3� knockout mice showed that GSK3� plays a significant role in renal water reabsorption by regulating aquaporin 2 expression in response to vasopressin. In the GSK3� knockout mice, adenylate cyclase activity and cAMP levels were reduced by an undetermined mechanism, which could have led to low aquaporin 2 expression and trafficking in response to vasopressin. Based on these evidences we hypothesize that GSK3� plays a critical role in renal water homeostasis. The role of this kinase in normal renal water reabsorption will be determined in the following 3 aims. 1) The first aim will determine how GSK3 regulates adenylate cyclase activity by examining if GSK3 binds to or phosphorylates adenylate cyclase using site directed mutagenesis. 2) The mechanism by which AVP signaling activates GSK3 will be determined by testing the hypothesis that AVP signaling activates GSK3 by inhibiting the canonical Wnt signaling. A negative feedback loop by which protein kinase A might regulate GSK3 will also be examined. 3) The third aim will test the hypothesis that AVP resistant- lithium induced NDI is a pathophysiological consequence of inhibition of renal GSK3. Since increased AVP signaling and high cAMP levels contribute to the progression of polycystic kidney disease, this aim will also test the hypothesis that inhibition or gene deletion of GSK3 can reduce cystogenesis. These studies will utilize wild type and collecting duct specific GSK3� knockout mice, primary cultures of inner medullary collecting duct cells and mouse cortical collecting duct cells. Through these studies we exoect to identify the mechanism by which GSK3 regulates AVP signaling in the renal collecting duct and its physiological and pathophysiological significance.

描述（由申请人提供）：糖原合成酶激酶 3 (GSK3) 是丝氨酸/苏氨酸蛋白激酶家族，由两种亚型 GSK3a 和 GSK3� 组成，已知 GSK3� 在肾脏中调节细胞分化和正常上皮功能。尽管体外和体内证据表明，双相情感障碍的常用疗法和 GSK3 的有效抑制剂锂可以降低肾脏对加压素中，GSK3� 在肾水转运中的作用尚不清楚。我们在锂诱导的多尿小鼠模型以及集合管特异性 GSK3� 敲除小鼠中的观察表明，GSK3� 通过调节水通道蛋白 2 在肾水重吸收中发挥重要作用。在 GSK3 敲除小鼠中，腺苷酸环化酶活性和 cAMP 水平因未确定的机制而降低。导致水通道蛋白 2 的低表达和转运以响应加压素。根据这些证据，我们发现 GSK3� 在肾水稳态中发挥着关键作用。该激酶在正常肾水重吸收中的作用将通过以下 3 个目标来确定。 1) 第一个目标是通过定点检测 GSK3 是否与腺苷酸环化酶结合或磷酸化腺苷酸环化酶来确定 GSK3 如何调节腺苷酸环化酶活性。 2) AVP 信号传导激活 GSK3 的机制将通过测试 AVP 信号传导通过抑制经典 Wnt 信号传导来激活 GSK3 的假设来确定，蛋白激酶 A 可能通过该负反馈环路调节 GSK3。第三个目标将检验以下假设：AVP 耐药性锂诱导的 NDI 是抑制肾脏 GSK3 的病理生理学结果，因为 AVP 信号传导的增加和高 cAMP 水平有助于 NDI 的进展。多囊肾病，这一目标还将测试 GSK3 的抑制或基因缺失可以减少囊肿发生的假设。这些研究将利用野生型和集合管特异性 GSK3™ 敲除小鼠、内髓集合管细胞和小鼠皮质集合管的原代培养物。通过这些研究，我们希望确定 GSK3 调节肾集合管中 AVP 信号传导的机制及其生理和病理生理意义。