Regulation of Renal Response to Vasopressin by Glycogen Synthase

糖原合酶调节肾脏对加压素的反应

• 批准号: 8541003
• 负责人: Reena Rao
• 金额: $ 31.69万
• 依托单位: UNIVERSITY OF KANSAS MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-20 至 2016-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8541003
• 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

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（由应用提供）：糖原合酶激酶3（GSK3）是丝氨酸/苏氨酸蛋白激酶的家族，由两个同工型，GSK3A和GSK3。在肾脏中，众所周知，GSK3曾调节细胞分化和正常的上皮功能。尽管体外和体内证据表明，锂，对躁郁症的常见疗法和GSK3的潜在抑制剂可以降低肾脏对加压素的反应，但GSK3缺在肾脏水运输中的作用尚不清楚。我们在锂诱导的多尿小鼠模型以及收集管道特异性GSK3？基因敲除小鼠中的观察结果表明，通过调节肾通道蛋白2对血管加压素的响应，GSK3€在肾脏水重吸收中起重要作用。在GSK3敲除小鼠中，腺苷酸环化酶活性和cAMP水平通过不确定的机制降低，这可能导致水通道蛋白2的表达较低，而对加压素的响应进行了运输。基于这些证据，我们假设GSK3在肾水稳态中起着至关重要的作用。该激酶在正常肾脏水吸附中的作用将在以下3个目标中确定。 1）第一个目的将通过检查GSK3是否使用定位的诱变来调节GSK3如何通过检查GSK3与腺苷酸环化酶结合或磷酸化来调节腺苷酸环化酶活性。 2）通过测试AVP信号传导通过抑制规范的Wnt信号传导激活GSK3的假设来确定AVP信号传导激活GSK3的机制。还将检查蛋白激酶A可能调节GSK3的负反馈回路。 3）第三个目标将检验以下假设：AVP抗lithium诱导的NDI是抑制肾脏GSK3的病理生理后果。由于AVP信号的增加和高cAMP水平有助于多囊性肾脏疾病的发展，因此该目标还将检验以下假设：GSK3的抑制或基因缺失可以减少囊生。这些研究将利用野生型和收集管道特异性GSK3敲除小鼠，内部髓质收集管细胞的主要培养物和小鼠皮质收集管细胞。通过这些研究，我们将GSK3调节肾脏收集导管中的AVP信号传导及其物理和病理生理学意义的机制。