Na,K-ATPase mediated ouabain effects in polycystic kidney disease

Na,K-ATP酶介导的哇巴因在多囊肾病中的作用

• 批准号: 8479348
• 负责人: V GUSTAVO BLANCO
• 金额: $ 29.74万
• 依托单位: UNIVERSITY OF KANSAS MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-06-01 至 2015-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8479348
• 关键词: Adhesions; Affect; Affinity; Apoptosis; Architecture; Autosomal Dominant Polycystic Kidney; Biological; Biology; Blood; Caspase; Cell Proliferation; Cells; Chronic Kidney Failure; Cyclins; Cyst; Cystic kidney; Data; Development; Disease; Epidermal Growth Factor Receptor; Epithelial; Epithelial Cells; Epithelium; Event; Exhibits; Fluids and Secretions; Functional disorder; Future; Gene Mutation; Genetic; Goals; Growth; Hormones; Human; In Vitro; Inherited; Insecta; Intervention; Investigation; Ion Transport; Ions; Kidney; Kidney Diseases; Laboratories; Liquid substance; Mediating; Metabolism; Mitogen-Activated Protein Kinase Kinases; Molecular; Movement; Na(+)-K(+)-Exchanging ATPase; Organ Culture Techniques; Ouabain; Pathway interactions; Patients; Phenotype; Phosphorylation; Polycystic Kidney Diseases; Predisposition; Property; Proprotein Convertase 1; Proprotein Convertase 2; Proteins; Publishing; Receptor Signaling; Relaxation; Renal function; Research; Role; Series; Signal Transduction; Sodium Chloride; Structure; System; Testing; Transducers; Tubular formation; Water; Work; base; cell growth; cell motility; cell type; design; disorder control; expectation; in vivo; innovation; kidney cell; kidney epithelial cell; kinase inhibitor; migration; mouse model; mutant; novel; ouabain receptor; polycystic kidney disease 1 protein; public health relevance; research study; src-Family Kinases; tool

DESCRIPTION (provided by applicant): Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited disease of the kidney, caused by alterations of polycystin 1 and 2 (PC1 and PC2). ADPKD is characterized by multiple fluid-filled cysts that affect the structure and function of the kidney, leading to chronic renal failure. Because of its essential function in the vectorial movement of salt and water in the kidney, the Na,K-ATPase has been the focus of investigation to understand the pathophysiology of ADPKD. However, the precise role of the Na,K-ATPase in ADPKD remains unknown. Interestingly, besides its activity as an ion transporter, the Na,K-ATPase also functions as the receptor for ouabain. Ouabain is a well characterized hormone known to trigger signaling events that induce changes in metabolism, motility and growth in several cell types. Surprisingly, we have found that the Na,K-ATPase of epithelial cells from kidney cysts of patients with ADPKD (ADPKD cells) exhibit an abnormal increase in the affinity for ouabain. Moreover, we have found that ouabain, in amounts similar to those circulating in blood, stimulates cell growth in ADPKD cells. This effect is not found in normal human kidney epithelial cells (NHK cells), which have a lower affinity for the hormone. Furthermore, ouabain enhances ADPKD cell apoptosis, in a manner that does not parallel the increase in cell proliferation; decreases the adhesion properties of the cells; and enhances their ability to form cysts in culture. All these events are hallmarks of ADPKD cystogenesis. Accordingly, we have found that ouabain exacerbates renal cyst development in a mouse model of ADPKD, both in vitro and in vivo. Altogether, these results suggest that ouabain is a novel factor that promotes renal cyst formation and progression. At present, the role and mechanisms by which ouabain mediates cyst formation in ADPKD cells are unknown. Our overall goal in this research is to understand how Na,K-ATPase-ouabain signaling affects ADPKD. Our central hypothesis is that, due to their high ouabain sensitive phenotype, ADPKD cells are more susceptible to circulating levels of the hormone; which abnormally stimulates Na,K-ATPase signaling, to cause hyperplasic growth, fluid secretion and changes in the adhesion properties and motility of the cells. Experiments are designed to determine the mechanisms of ouabain stimulated Na,K-ATPase signaling in cyst formation of ADPKD cells, the intracellular pathways responsible for ouabain action on the cells, and the determinants of the abnormal ouabain affinity of ADPKD cells. The results will have an important positive impact, because they will help define the molecular mechanisms involved in cyst development and progression in ADPKD, and will contribute in the future to develop approaches that will target Na,K-ATPase signaling to control the disease.

描述（由申请人提供）：常染色体显性多囊肾病（ADPKD）是最常见的肾脏遗传性疾病，由多囊蛋白 1 和 2（PC1 和 PC2）的改变引起。 ADPKD 的特点是多个充满液体的囊肿，影响肾脏的结构和功能，导致慢性肾功能衰竭。由于 Na,K-ATP 酶在肾脏中盐和水的矢量运动中发挥重要作用，因此它已成为了解 ADPKD 病理生理学的研究重点。然而，Na,K-ATP 酶在 ADPKD 中的确切作用仍不清楚。有趣的是，除了作为离子转运蛋白的活性外，Na,K-ATP 酶还充当哇巴因的受体。哇巴因是一种特征明确的激素，已知可触发信号事件，从而诱导多种细胞类型的新陈代谢、运动和生长发生变化。令人惊讶的是，我们发现ADPKD患者肾囊肿上皮细胞（ADPKD细胞）的Na,K-ATP酶对哇巴因的亲和力异常增加。此外，我们发现哇巴因的量与血液中循环的量相似，可刺激 ADPKD 细胞的细胞生长。在正常人肾上皮细胞（NHK 细胞）中未发现这种效应，因为正常人肾上皮细胞对激素的亲和力较低。此外，哇巴因以一种与细胞增殖增加并不平行的方式增强 ADPKD 细胞凋亡。降低细胞的粘附性能；并增强它们在培养物中形成包囊的能力。所有这些事件都是 ADPKD 囊肿发生的标志。因此，我们发现哇巴因在 ADPKD 小鼠模型中在体外和体内都会加剧肾囊肿的发展。总而言之，这些结果表明哇巴因是促进肾囊肿形成和进展的新因子。目前，哇巴因介导 ADPKD 细胞囊肿形成的作用和机制尚不清楚。我们这项研究的总体目标是了解 Na,K-ATPase-哇巴因信号如何影响 ADPKD。我们的中心假设是，由于 ADPKD 细胞具有高度哇巴因敏感表型，因此更容易受到循环激素水平的影响；它异常刺激 Na,K-ATP 酶信号传导，导致细胞增生生长、液体分泌以及细胞粘附特性和运动性的变化。实验旨在确定 ADPKD 细胞囊肿形成中哇巴因刺激 Na,K-ATP 酶信号传导的机制、负责哇巴因对细胞作用的细胞内途径以及 ADPKD 细胞异常哇巴因亲和力的决定因素。这些结果将产生重要的积极影响，因为它们将有助于确定 ADPKD 囊肿发育和进展所涉及的分子机制，并将有助于未来开发针对 Na,K-ATP 酶信号传导来控制疾病的方法。