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)： 水通过生物膜运输有两条途径：脂类扩散和水通道介导的运输。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。AQP2就是这个家族中的一员。AQP2是哺乳动物肾脏集合管的主细胞中的一条重要的水通道，调节水的动态平衡。除了正在进行的关于AQP2转运的令人兴奋的研究外，越来越多的动物数据表明，除了在水或小溶质运输中的经典作用外，水通道蛋白还可能在关键的生物学过程中发挥额外的作用，如：神经信号转导、细胞迁移和血管生成。在小鼠AQP2 T126M敲入模型中的研究表明，导致AQP2内质网滞留的突变存在尿液浓缩缺陷(肾源性尿崩症，NDI)，并且出人意料地，新生儿死于肾功能衰竭。纯合子小鼠的活组织检查显示肾小管坏死和囊性形成。这一不同寻常的发现促使我们研究AQP2在肾脏发育中的潜在新功能。我们的初步研究表明，AQP2确实在上皮细胞的迁移和黏附中发挥作用。因此，我们认为AQP2通过影响肾小管上皮细胞迁移、细胞-细胞和细胞-基质相互作用，在肾小管的发育、成熟或维持完整性中发挥重要作用。在这些研究中，我们将利用斑马鱼系统来研究AQP2在体内的这些新功能。具体地说，我们将研究AQP2同源基因在野生型斑马鱼和带有肾囊的斑马鱼中的时空表达，并研究在这些条件下AQP2运输的任何变化；2)通过使用吗啉抑制AQP2功能并在体外通过组织特异性过表达产生运输缺陷和迁移缺陷的突变，研究AQP2在斑马鱼前肾发育/成熟中的作用。我们的研究不仅有助于理解AQP2新功能的分子机制，也有助于理解经典通道蛋白对上皮细胞生物学其他重要方面的意外贡献。 与公共卫生相关：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。它们能快速输送大量的水，并为跨膜水运输提供了一条主要途径。AQP2是这个家族中的一员，是哺乳动物肾脏主细胞中调节水稳态的重要水通道。