Role of adenylyl cyclase isoforms in collecting duct physiology & pathophysiology

腺苷酸环化酶亚型在集合管生理学中的作用

• 批准号: 8895765
• 负责人: Donald E Kohan
• 金额: $ 32.42万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-15 至 2016-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8895765
• 关键词: A Mouse; Adenylate Cyclase; Affect; Animals; Autosomal Dominant Polycystic Kidney; Biochemistry; Bladder Control; Blood Pressure; Cells; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Cyst; Cystic Kidney Diseases; Data; Development; Disease; Duct (organ) structure; Endocrine; Engineering; Excretory function; Figs - dietary; Functional disorder; Genes; Health; Hypertension; Individual; Kidney; Knock-out; Mediating; Metabolism; Modality; Mus; Pathogenesis; Pathway interactions; Physiological; Physiology; Play; Polycystic Kidney Diseases; Production; Protein Isoforms; Proteins; Regulation; Research Design; Role; Signal Pathway; Signal Transduction; Signaling Molecule; Sodium; Structure; Therapeutic; Vasopressins; Water; autocrine; base; blood pressure regulation; cell water; design; in vivo; inhibitor/antagonist; interest; loss of function; mouse model; novel; paracrine; phosphoric diester hydrolase; polycystic kidney disease 1 protein; pressure; public health relevance; urinary

DESCRIPTION (provided by applicant): The collecting duct principal cell (PC) is responsible for the final adjustment of renal Na and water excretion. Derangements in PC Na reabsorption are associated with most forms of monogenic hypertension, while altered PC water transport accompanies disorders of water metabolism. PC Na and water transport are subject to the influences of multiple autocrine, paracrine and endocrine factors. A key mechanism for mediating many of these effects involves signaling through adenylyl cyclase (AC)-derived cAMP. The PC expresses AC3, 4 and 6, raising the fundamental question as to which biologic effects individual AC isoforms exert in the PC. We have engineered mice with PC-specific disruption of AC3, 4 or 6, and have found exciting new evidence for unique roles of the PC AC isoforms, AC3 and 6. Our findings suggest that AC6 regulates PC Na and water transport, while AC3 selectively affects PC water transport. Based on these novel findings, together with the currently increasing interest in designing inhibitors specific for individual AC isoforms as therapeutic modalities, this proposal will define the role of the specific AC isoforms, AC3 and 6 in the regulation of PC Na and water transport. In addition, cAMP in the PC is not only important in regulating Na and water transport, but it can be of primary importance in disease. In particular, disordered cAMP production and actions in autosomal dominant polycystic kidney disease play a fundamental role in cyst development and expansion. In preliminary studies, we have obtained exciting new data suggesting that targeting AC6 is markedly protective against the development of cystic kidney disease in a mouse model. Consequently, this proposal will define the role of specific AC isoforms in the PC in the pathogenesis of polycystic kidney disease. The major hypotheses of this proposal are: 1) AC3 and 6 in the PC exert distinctive effects on PC Na and water transport in health; and 2) AC3 and 6 in the PC differentially modulate PC development into cysts in polycystic kidney disease. The proposal has three specific aims: 1) Aim 1 will determine the physiologic role of PC AC isoforms (AC3 and 6) in renal Na and water handling. Each AC isoform will be selectively targeted in mouse PC in vivo. Intact animals and acutely isolated collecting ducts will be used to assess the role of the individual AC isoforms by loss of function in the regulation of blood pressure and Na and water excretion. 2) Aim 2 will determine the biochemistry of PC AC isoforms (AC3 and 6) related to control of cAMP levels and cAMP effects on Na and water transport. The mechanisms by which individual AC isoform-derived cAMP is modulated by vasopressin and exerts its biologic effects will be studied using mice with PC-specific knockout of AC3, 6 or both isoforms. In particular, these studies will define how cAMP derived from each AC isoform in the PC is metabolized by phosphodiesterases and which signaling molecules (protein kinase A and/or exchange protein directly activated by cAMP) are directly activated by each AC isoform in transducing vasopressin actions in the PC. 3) Aim 3 will determine the pathophysiologic effects of all PC AC isoforms (AC3 and 6) in polycystic kidney disease. A mouse model of polycystin-1 deficiency will be employed and the effect of simultaneously disrupting individual AC isoforms together with the Pkd1 gene on renal structure and function will be assessed. These studies will define which AC isoform(s) is/are important in the pathogenesis of polycystic kidney disease and will begin to identify the specific signaling pathways that individual AC isoforms modulate in polycystic kidney disease.

描述（由申请人提供）：收集导管主电池（PC）负责最终调整肾脏NA和水排泄物。 PC NA吸收的危险与大多数形式的单基质高血压有关，而PC水转运的变化伴随着水代谢的疾病。 PC NA和水运输受到多种自分泌，旁分泌和内分泌因素的影响。介导许多这些作用的关键机制涉及通过腺苷酸环化酶（AC）衍生的CAMP信号传导。 PC表示AC3、4和6，提出了一个基本问题，即单个AC同工型在PC中施加哪些生物学作用。我们已经对AC3、4或6的PC特异性破坏进行了设计，并找到了令人兴奋的新证据，证明了PC AC同工型，AC3和6的独特作用。我们的发现表明AC6调节PC NA和水运输，而AC3有选择地影响PC水的运输。基于这些新颖的发现，以及当前对设计针对单个AC同工型特异性抑制剂的兴趣，该建议将定义特定的AC同工型，AC3和6在PC NA和水运输中的作用。此外，PC中的营地不仅在调节NA和水运输方面很重要，而且在疾病中可能至关重要。尤其是，常染色体显性多囊肾脏疾病的营地生产和行动在囊肿发育和扩张中起着基本作用。在初步研究中，我们获得了令人兴奋的新数据，这表明靶向AC6在小鼠模型中明显保护囊性肾脏疾病。因此，该建议将定义特定AC同工型在PC中在多囊肾脏疾病的发病机理中的作用。该提案的主要假设是：1）PC中的AC3和6对PC NA和健康中的水运输具有独特的影响； 2）PC中的AC3和6将PC发育调节为多囊性肾脏疾病中的囊肿。该提案具有三个特定的目的：1）AIM 1将确定PC AC同工型（AC3和6）在肾脏NA和水分处理中的生理作用。每个AC同工型将在体内选择性地靶向鼠标PC。完整的动物和急性分离的收集管将通过在血压和NA和水分排泄中的功能丧失来评估单个AC同工型的作用。 2）AIM 2将确定与控制营地水平以及对NA和水运输的影响有关的PC AC同工型（AC3和6）的生物化学。通过加压素调节单个AC同工型衍生的单个AC同工型cAMP的机制将使用具有AC3，6或两种同工型的PC特异性敲除小鼠进行研究。特别是，这些研究将定义如何从PC中的每种AC同工型中衍生的cAMP被磷酸二酯酶代谢，哪些信号分子（蛋白激酶A和/或由CAMP直接激活的蛋白激酶A和/或交换蛋白）在PC中直接激活了每种AC同工型。 3）AIM 3将确定所有PC AC同工型（AC3和6）在多囊肾脏疾病中的病理生理作用。将采用多囊1缺乏症的小鼠模型，并将评估同时破坏单个AC同工型以及PKD1基因对肾脏结构和功能的影响。这些研究将定义哪种AC同工型在多囊性肾脏疾病的发病机理中很重要，并将开始确定单个AC同工型在多囊肾脏疾病中调节的特定信号传导途径。