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: 8725137
• 负责人: Reena Rao
• 金额: $ 32.84万
• 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/8725137
• 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（由申请人提供）：糖原合酶激酶 3 (GSK3) 是一个丝氨酸/苏氨酸蛋白激酶家族，由两种同工型 GSK3a 和 GSK3¿在肾脏中，GSK3¿尽管体外和体内证据表明锂是双相情感障碍的常用疗法，也是 GSK3 的有效抑制剂，但已知它可以调节细胞分化和正常上皮功能。可以降低肾脏对加压素的反应，GSK3的作用¿我们在锂诱导多尿小鼠模型以及集合管特异性 GSK3 中的观察结果尚不清楚。基因敲除小鼠显示 GSK3¿在 GSK3 中，通过调节水通道蛋白 2 的表达，在肾水重吸收中发挥重要作用。在基因敲除小鼠中，腺苷酸环化酶活性和 cAMP 水平因未确定的机制而降低，这可能导致水通道蛋白 2 表达和运输对加压素的反应较低。根据这些证据，我们捕获了 GSK3¿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：第一个目标是通过检查 GSK3 是否与腺苷酸结合或磷酸化腺苷酸来确定 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 信号传导激活的假设来确定。 GSK3 通过抑制典型的 Wnt 信号传导来检测蛋白激酶 A 可能调节 GSK3 的负反馈环路。 3) 第三个目标将检验 AVP 抗性锂诱导的 NDI 是抑制肾 GSK3 的病理生理学结果的假设。由于 AVP 信号传导的增加和高 cAMP 水平会导致多囊肾病的囊肿进展，因此该目标还将检验 GSK3 的抑制或基因删除可以减少形成的假设。这些研究将利用野生型。类型和集合管特定 GSK3¿敲除小鼠、内髓集合管细胞和小鼠皮质集合管细胞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。