Using zebrafish to define a novel role for AQP2 in kidney tubulogenesis

利用斑马鱼定义 AQP2 在肾小管发生中的新作用

• 批准号: 7918801
• 负责人: HUA A LU
• 金额: $ 8.76万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2012-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7918801
• 关键词: Acute Kidney Failure; Adhesions; Adult; Affect; Animal Model; Biological; Biological Models; Biological Process; Biopsy; Cell membrane; Cells; Cellular biology; Cessation of life; Complex; Cyclic AMP; Cyclic GMP; Cyst; Cystic kidney; Cytoplasmic Vesicles; Data; Defect; Development; Diabetes Insipidus; Diffusion; Dimensions; Dominant-Negative Mutation; Embryo; Epithelial; Epithelial Cells; Event; Family; Homeostasis; Impairment; In Vitro; Kidney; Kidney Failure; Knock-in Mouse; Life; Light; Lipids; Liquid substance; Lower Organism; Maintenance; Mammalian Cell; Mediating; Membrane; Modeling; Molecular; Mus; Mutation; Names; Neonatal Mortality; Nephrogenic Diabetes Insipidus; Organism; Osmolar Concentration; Pathway interactions; Phosphorylation; Plants; Plasma; Play; Pronephric Duct; Pronephric structure; Proteins; RGD (sequence); Recruitment Activity; Regulation; Research; Role; Signal Transduction; System; Tissues; Transgenic Organisms; Tubular formation; Vasopressins; Vertebrates; Water; Zebrafish; angiogenesis; animal data; base; cell motility; cell type; collecting tubule structure; extracellular; functional loss; in vivo; in vivo Model; injury and repair; insight; knock-down; lipid metabolism; loss of function; migration; mouse model; mutant; neonate; nephrogenesis; novel; overexpression; relating to nervous system; response; solute; trafficking; tubular necrosis; urinary; water channel

DESCRIPTION (provided by applicant): Water is transported through biological membranes by two pathways: lipid diffusion and water channel-mediated transport. Water channels, also named aquaporins, are present in many cell types and tissues, plants and lower organisms. AQP2 is one of this family. AQP2 is an important water channel present in principal cells of the mammalian kidney collecting duct to regulate water homeostasis. In addition to the on-going exciting research on AQP2 trafficking, there are emerging data from animals indicating that besides their classic role in water or small solute transport, aquaporins may exert additional roles in critical biological processes such as: neural signal transduction, cell migration and angiogenesis. Studies in a mouse knock-in model of AQP2 T126M, a mutation causing ER retention of AQP2, showed a urinary concentrating defect (nephrogenic diabetes insipidus, NDI), and unexpectedly, neonatal mortality from renal failure. Biopsy of homozygous mice revealed kidney tubular necrosis and cyst formation. This unusual finding prompts us to investigate a potential novel function of AQP2 in kidney development. Our preliminary study suggests that AQP2 indeed plays a role in epithelial cells migration and adhesion. Therefore, we propose that AQP2 plays a critical role in the development, maturation or maintenance of renal tubular integrity via its effects on epithelial migration, cell-cell and cell- matrix interaction. For these studies we will take advantage of the well-characterized zebrafish system to investigate these novel functions of AQP2 in vivo. Specifically, we will investigate spatial and temporal expression of an AQP2 orthologue in wild-type zebrafish and zebrafish with kidney cysts, and investigate any alteration of AQP2 trafficking under these conditions; 2) investigate roles of AQP2 in development/maturation of the pronephros in zebrafish by knocking down AQP2 function using morpholinos, and via tissue specific overexpressing of AQP2 with mutations that produce trafficking defects and migration defects in vitro. Our proposed studies will contribute not only to the understanding of the molecular mechanism underlying a novel function of AQP2, but also provide understanding of the unexpected contribution of a classic channel protein to other important aspects of epithelial cell biology. PUBLIC HEALTH RELEVANCE: Water channels, also named aquaporins, are present in many cell types and tissues, plants and lower organisms. They transport bulk water rapidly and provide a major pathway for transmembrane water transport. AQP2 is one of this family, and is an important water channel present in principal cells of the mammalian kidney to regulate water homeostasis.

描述（由申请人提供）： 水通过两种途径通过生物膜转运：脂质扩散和水通道介导的转运。水通道，也称为水通道蛋白，存在于许多细胞类型和组织、植物和低等生物中。AQP 2就是其中之一。AQP 2是存在于哺乳动物肾脏集合管主要细胞中调节水稳态的重要水通道。除了正在进行的关于AQP 2运输的令人兴奋的研究之外，还有来自动物的新数据表明，除了它们在水或小溶质运输中的经典作用之外，水通道蛋白可能在关键的生物过程中发挥额外的作用，例如：神经信号转导，细胞迁移和血管生成。在小鼠AQP 2 T126 M基因敲入模型（一种导致AQP 2 ER滞留的突变）中的研究显示了尿浓缩缺陷（肾源性尿崩症，NDI），以及意外的肾衰竭新生儿死亡率。纯合子小鼠的活检显示肾小管坏死和囊肿形成。这一不寻常的发现促使我们研究AQP 2在肾脏发育中的潜在新功能。我们的初步研究表明，AQP 2确实在上皮细胞的迁移和粘附中发挥作用。因此，我们认为AQP 2通过其对上皮迁移、细胞-细胞和细胞-基质相互作用的影响，在肾小管完整性的发育、成熟或维持中发挥着关键作用。对于这些研究，我们将利用良好的特点，斑马鱼系统，在体内研究这些新的功能AQP 2。具体来说，我们将研究野生型斑马鱼和患有肾囊肿的斑马鱼中AQP 2直向同源物的空间和时间表达，并研究在这些条件下AQP 2运输的任何改变; 2）通过用吗啉代敲低水通道蛋白2的功能，研究水通道蛋白2在斑马鱼原肾发育/成熟中的作用，以及通过组织特异性过表达具有突变的AQP 2，在体外产生运输缺陷和迁移缺陷。我们提出的研究不仅有助于理解AQP 2的新功能的分子机制，而且还提供了一个经典的通道蛋白对上皮细胞生物学的其他重要方面的意想不到的贡献的理解。 水通道，也称为水通道蛋白，存在于许多细胞类型和组织，植物和低等生物中。它们快速运输大量的水，并提供跨膜水运输的主要途径。AQP 2是该家族中的一员，是哺乳动物肾脏主要细胞中调节水稳态的重要水通道。