Transport Mechanism and Renal Function of a Newly Recognized Na+/H+ Exchanger

新认识的Na /H交换剂的转运机制和肾功能

基本信息

批准号：
9339660
负责人：
RAJINI RAO
金额：
$ 45.11万
依托单位：
JOHNS HOPKINS UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-09-21 至 2020-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9339660
关键词：
3-Dimensional Acids Adult Affect Alpha Cell Animal Model Autosomal Dominant Polycystic Kidney Biological Transport Blood Pressure Cations Cell Line Cell membrane Cell model Cells Clinical Complication Computerized Medical Record Cyst Cystic kidney DNA Databases Developed Countries Diabetic Nephropathy Disease Distal Duct (organ) structure Epithelial Cells Epitopes Equilibrium Erythrocytes Essential Hypertension Etiology Evaluation Family Genetic study Genotype Goals Health Heart failure Hormonal Human Human Genome Hypertension In Vitro Inherited Ion Transport Kidney Kidney Diseases Kidney Failure Label Laboratories Link Liquid substance Lithium MDCK cell Measures Mediating Modeling Modernization Molecular Molecular Conformation Mus Mutagenesis Nephrons Neurologic Organism Orthologous Gene Pathologic Patients Phenotype Phylogenetic Analysis Physiological Play Property Proteins Protons Regulation Renal function Renal tubule structure Risk Factors Role Salts Site Sodium Sodium Chloride Structural Models Structure Testing Toxic effect Transcript Transport Process United States Validation Variant Vasopressins Water Yeasts antiporter base biochemical tools blood pressure regulation cardiovascular risk factor diabetic disease phenotype exome sequencing experimental study genome database high salt diet hormone regulation human disease in vivo inhibitor/antagonist innovation insight member mouse model nervous system disorder neuropsychiatric disorder novel overexpression pH Homeostasis polarized cell protein folding response screening three dimensional cell culture tool trafficking trait vasopressin resistant diabetes insipidus water channel western diet

项目摘要

Project Summary Hypertension is a major health problem affecting more than 1 in 4 adults in the United States and is an independent risk factor for heart and kidney failure. Approximately 95% of cases are idiopathic and classified as essential hypertension. Increased Na+-Li+ countertransport (SLC) is a well-characterized inheritable trait and known marker for essential hypertension and diabetic nephropathy. SLC represents an alternative mode of Na+/H+ exchange and correlates with sodium transport in the renal tubule. Recently, our laboratory identified NHA2, a novel sodium proton (Na+/H+) antiporter that mediates SLC, and is expressed in the distal nephron of the kidney. NHA2 is a member of a phylogenetically distinct and uncharacterized branch of the superfamily of metazoan cation proton transporters that includes the well-known NHE family of transporters. In Aim 1, we will generate and test model structures of NHA2 based on similarity with bacterial and archaeal orthologs of known structures in outward and inward facing conformations. The predictive power of the structural models, combined with functional screening of transport phenotypes in yeast, will be tested against a database of human variants and patient electronic medical records in an innovative PheWAS approach to link genotypes to disease phenotypes. Our preliminary observations implicate NHA2 in renal cyst formation and point to a potential role in nephrogenic diabetes insipidus, a major complication in patients prescribed lithium for bipolar and other neurological disorders. Therefore, in Aim 2 we will use renal epithelial cell models and 3-dimensional cysts to determine the role of NHA2 in salt and pH homeostasis. Modern Western diet is high in sodium and is known to be associated with hypertension. In preliminary experiments, we have observed elevation of NHA2 transcript and protein in mice fed a high salt diet. Experiments in Aim 3 will investigate the salt induction of NHA2 in the kidney and the role of NHA2 in salt and pH homeostasis by extrapolation to animal models. We will directly test whether NHA2 is responsible for SLC activity in red cells from mouse and human. This proposal will provide the first mechanistic and functional insights on a novel human Na+ transporter and its relevance to hypertension and human disease.

项目摘要高血压是影响美国四分之一以上的主要健康问题，是一个心脏和肾衰竭的独立危险因素。大约95％的病例是特发性和分类的作为重要的高血压。增加Na+ -Li+反向转运（SLC）是一个特征良好的遗传性状，已知的高血压和糖尿病性肾病的标记。 SLC代表一种替代模式 Na+/H+交换并与肾小管中的钠转运相关。最近，我们的实验室确定了 NHA2，一种介导SLC的新型钠质子（Na+/H+）的抗植物肾脏。 NHA2是该超家族的系统发育范围不同和未表征的分支的成员后生阳离子质子转运蛋白包括著名的NHE转运蛋白家族。在AIM 1中，我们将基于与已知的细菌和古细菌直系同源物的NHA2生成和测试模型结构外在和内向的结构面向构象。结构模型的预测能力，结合酵母中运输表型的功能筛选，将根据数据库进行测试在创新的Phewas方法中，人类变体和患者电子病历将基因型联系起来疾病表型。我们的初步观察结果暗示了NHA2在肾脏囊肿形成中，并指向在肾脏基质糖尿病中的潜在作用，这是患者开处方锂的主要并发症和其他神经系统疾病。因此，在AIM 2中，我们将使用肾上皮细胞模型和3维确定NHA2在盐和pH稳态中的作用的囊肿。现代西方饮食的钠很高，是已知与高血压有关。在初步实验中，我们观察到NHA2的升高小鼠的转录本和蛋白质喂养高盐饮食。 AIM 3中的实验将研究诱导的盐 NHA2在肾脏中以及NHA2在盐和pH稳态中的作用通过外推到动物模型中。我们将直接测试NHA2是否负责小鼠和人类红细胞中的SLC活性。这提案将为新型的人Na+转运蛋白及其提供第一个机械和功能见解与高血压和人类疾病有关。