Membrane Trafficking of Renal Ion Transport Proteins in Potassium Homeostasis

钾稳态中肾离子转运蛋白的膜运输

基本信息

批准号：
8725134
负责人：
Chou-Long Huang
金额：
$ 46.96万
依托单位：
UT SOUTHWESTERN MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2003
资助国家：
美国
起止时间：
2003-06-01 至 2016-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8725134
关键词：
Address Adrenalectomy Affect Aldosterone Apical Bladder Control Blood Carrier Proteins Cells Diet Dietary intake Disease Distal Diuretics Down-Regulation Electrolytes Elements Embryo Excretory function Gene Mutation Glucocorticoids Goals Heart Diseases Homeostasis Hypertension In Vitro Infusion procedures Intake Ion Transport KCNJ1 gene Kidney Kidney Diseases Knockout Mice Lead Length Measures Mediating Membrane Protein Traffic Mus Mutant Strains Mice Myopathy Nephrons Operative Surgical Procedures Pathway interactions Phosphorylation Phosphotransferases Physiological Physiology Plasma Play Potassium Potassium Channel Protein Kinase RNA Splicing Regulation Relative (related person)Reporting Research Rodent Role Staining method Stains Testing Transcript Type II Pseudohypoaldosteronism Up-Regulation Variant Western Blotting base density driving force epithelial Na+ channel hyperkalemia in vivo insight mouse model operation overexpression promoter research study response urinary

项目摘要

DESCRIPTION (provided by applicant): The kidney adjusts K+ secretion in the distal nephron in response to variations in dietary intake to maintain K+ homeostasis. The distal K+ secretion involves K+ efflux from the cell into the lumen through apical K+ channels such as ROMK. Na+ reabsorption via the epithelial Na+ channel ENaC provides the electrical driving force for K+ secretion. An increase in the activity of the Na-Cl cotransporter NCC may decrease Na+ delivery to ENaC thus diminishing K+ secretion. In support for the role of NCC as well as ROMK in maintaining K+ homeostasis during dietary variations of K+ intake, high K+ loading in rodents increases the density of ROMK while decreasing the density of NCC in the distal nephron. The upstream regulation of ROMK and NCC remains incompletely understood. WNK1 is a protein kinase of which gene mutations resulting in increased expression cause pseudohypoaldosteronism type II (PHA2), an autosomal-dominant disease characterized by hypertension and hyperkalemia. WNK1 has several alternatively spliced variants including a ubiquitous full- length long WNK1 (L-WNK1) and a shorter kidney-specific WNK1 (KS-WNK1). Cell-based expression studies have shown that L-WNK1 activates NCC and inhibits ROMK. KS-WNK1, by itself, does not regulate NCC and ROMK but reverses L-WNK1-mediated activation and inhibition of NCC and ROMK, respectively. The long- term goal of our research is to understand K+ homeostasis in the normal physiology and in diseased states. Here, we will examine three specific aims. Aim 1 is to examine the physiological role and mechanism of L- WNK1 in the regulation of renal Na+ and K+ transport. Aim 2 is to examine the hypothesis that KS-WNK1 antagonizes L-WNK1 regulation of renal Na+ and K+ transport and changes in dietary K+ affect the ratio of L- over KS-WNK1 to regulate NCC and ROMK. Aim 3 is to examine the interplay between aldosterone and L- and KS-WNK1 pathway in the regulation of renal Na+ and K+ transport and the response to variations in dietary K+. We have generated mouse models with genetically altered expression of L-and/or KS-WNK1. Renal Na+ and K+ transport in these mice will be studied by measuring blood and urinary electrolytes and expression of Na+ and K+ transporters in response to dietary Na+ or K+ perturbations and to diuretics. K+ secretion will also be studied by in vitro microperfusion of isolated CCD tubules. Surgical adrenalectomy will be performed to examine interactions between aldosterone and WNK1 pathway. These studies will provide important insights to the in vivo role of WNK1 in renal Na+ and K+ transport in the normal physiology and in diseased states.

描述（由申请人提供）：肾脏根据饮食摄入的变化调整远端肾单位的 K+ 分泌，以维持 K+ 稳态。远端 K+ 分泌涉及 K+ 通过顶端 K+ 通道（例如 ROMK）从细胞流出到管腔。通过上皮 Na+ 通道的 Na+ 重吸收 ENaC 为 K+ 分泌提供电驱动力。 Na-Cl 协同转运蛋白 NCC 活性的增加可能会减少 Na+ 向 ENaC 的输送，从而减少 K+ 的分泌。啮齿动物的高 K+ 负荷增加了远端肾单位中 ROMK 的密度，同时降低了 NCC 的密度，这支持了 NCC 和 ROMK 在 K+ 摄入量饮食变化期间维持 K+ 稳态的作用。 ROMK 和 NCC 的上游调控仍不完全清楚。 WNK1 是一种蛋白激酶，其基因突变导致表达增加，导致 II 型假性醛固酮增多症 (PHA2)，这是一种以高血压和高钾血症为特征的常染色体显性遗传疾病。 WNK1 具有多种选择性剪接变体，包括普遍存在的全长长 WNK1 (L-WNK1) 和较短的肾脏特异性 WNK1 (KS-WNK1)。基于细胞的表达研究表明，L-WNK1 激活 NCC 并抑制 ROMK。 KS-WNK1 本身不调节 NCC 和 ROMK，但分别逆转 L-WNK1 介导的 NCC 和 ROMK 激活和抑制。我们研究的长期目标是了解正常生理和疾病状态下的 K+ 稳态。在这里，我们将研究三个具体目标。目的1是研究L-WNK1在调节肾脏Na+和K+转运中的生理作用和机制。目标 2 是检验以下假设：KS-WNK1 拮抗 L-WNK1 对肾脏 Na+ 和 K+ 转运的调节，并且膳食 K+ 的变化会影响 L- 与 KS-WNK1 的比例来调节 NCC 和 ROMK。目标 3 是检查醛固酮与 L- 和 KS-WNK1 通路在肾脏 Na+ 和 K+ 转运调节中的相互作用以及对饮食 K+ 变化的反应。我们已经生成了 L-和/或 KS-WNK1 表达基因改变的小鼠模型。将通过测量血液和尿液电解质以及 Na+ 和 K+ 转运蛋白对饮食 Na+ 或 K+ 扰动和利尿剂的反应来研究这些小鼠的肾脏 Na+ 和 K+ 转运。还将通过分离的 CCD 小管的体外微灌注来研究 K+ 分泌。将进行肾上腺切除术以检查醛固酮和 WNK1 通路之间的相互作用。这些研究将为了解 WNK1 在正常生理和疾病状态下肾脏 Na+ 和 K+ 转运中的体内作用提供重要见解。

项目成果

期刊论文数量（9）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Recent advances in distal tubular potassium handling.

远端肾小管钾处理的最新进展。

DOI：
10.1152/ajprenal.00742.2010
发表时间：
2011
期刊：
American journal of physiology. Renal physiology
影响因子：
0
作者：
Rodan,AylinR;Cheng,Chih-Jen;Huang,Chou-Long
通讯作者：
Huang,Chou-Long

Zebrafish WNK lysine deficient protein kinase 1 (wnk1) affects angiogenesis associated with VEGF signaling.

DOI：
10.1371/journal.pone.0106129
发表时间：
2014
期刊：
PloS one
影响因子：
3.7
作者：
Lai JG;Tsai SM;Tu HC;Chen WC;Kou FJ;Lu JW;Wang HD;Huang CL;Yuh CH
通讯作者：
Yuh CH

A unifying mechanism for WNK kinase regulation of sodium-chloride cotransporter.

DOI：
10.1007/s00424-015-1708-2
发表时间：
2015-11
期刊：
Pflugers Archiv : European journal of physiology
影响因子：
0
作者：
Huang CL;Cheng CJ
通讯作者：
Cheng CJ

Expression and function of the epithelial sodium channel δ-subunit in human respiratory epithelial cells in vitro.

体外人呼吸道上皮细胞上皮钠通道δ亚基的表达和功能。

DOI：
10.1007/s00424-015-1693-5
发表时间：
2015
期刊：
Pflugers Archiv : European journal of physiology
影响因子：
0
作者：
Schwagerus,Elena;Sladek,Svenja;Buckley,StephenT;Armas-Capote,Natalia;AlvarezdelaRosa,Diego;Harvey,BrianJ;Fischer,Horst;Illek,Beate;Huwer,Hanno;Schneider-Daum,Nicole;Lehr,Claus-Michael;Ehrhardt,Carsten
通讯作者：
Ehrhardt,Carsten

Distal potassium handling based on flow modulation of maxi-K channel activity.