The experiments proposed herein will explore new models for effects of WNK kinases, kelch-like 3, and cullin 3 on the thiazide-sensitive Na-Cl cotransporter (NCC). The NCC of the mammalian kidney is essential to normal blood pressure regulation and to normal potassium balance. Mutations in the transporter cause salt wasting and hypokalemia. Mutations in the WNK kinases, kelch-like 3 or cullin 3 lead to hypertension and hyperkalemia by activating the transporter. Despite intense efforts, mechanisms by which these mutations cause human disease remain unclear. We have recently developed two novel mouse models, permitting us to study how the WNK kinases and cullin 3 signal to the thiazide-sensitive transporter, in vivo. These models compel us to propose novel, paradigm-shifting models for WNK and cullin 3 signaling to NCC. Here, we propose to determine how WNK4 can act both as an inhibitor and a stimulator of ion transport in the distal nephron. We will also test how interactions with other members of the WNK kinase family help to explain the sometimes-contradictory results obtained in the literature. We will also test a new model for cullin 3 regulation in NCC, one in which cullin 3 feeds back to regulate kelch-like 3, giving cullin 3 both stimulatory and inhibitory effects on NCC. To accomplish these goals, we have recruited three prominent research groups from around the world to work together. We will take the models generated using in vivo approaches, and explore the mechanisms involved using well-established in vitro approaches. To this end, we will 1) Determine how the WNK signaling complex formation modulates NCC activity, and 2) Determine how CRL activity modulates WNK kinase signaling.
These aims will be performed using both in vivo and in vitro techniques, insuring that conclusions are physiologically sound and relevant. The long-term goal is to determine how balance and sodium balance can be separated pharmacologically. Mutations in WNK kinases, kelch-like 3 and cullin 3 appear to dissociate the potassium-wasting effects of aldosterone from the sodium- retaining effects. We hope to learn how the kidney normally recognizes whether to excrete potassium or reabsorb salt, so that we can develop dietary better approaches to prevent hypertension, and better pharmaceutical approaches to treat it.

Public Health Relevance

Even though high blood pressure result from mutations in several genes. Rare cases that result from single gene mutations are helpful to identify kidney pathways that control blood pressure. This work is designed to understand how several proteins work together to help humans balance the need to retain or excrete either salt or potassium. This work has broad relevance towards both to prevent and treat hypertension in humans, and how to devise new approaches for hypertension drug development.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
2R01DK051496-15A1
Application #
8839098
Study Section
Pathobiology of Kidney Disease Study Section (PBKD)
Program Officer
Ketchum, Christian J
Project Start
1998-08-01
Project End
2019-02-28
Budget Start
2015-03-04
Budget End
2016-02-29
Support Year
15
Fiscal Year
2015
Total Cost
$532,870
Indirect Cost
$152,573
Name
Oregon Health and Science University
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
096997515
City
Portland
State
OR
Country
United States
Zip Code
97239
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Li, Ai-Jun; Wang, Qing; Ritter, Sue (2018) Selective Pharmacogenetic Activation of Catecholamine Subgroups in the Ventrolateral Medulla Elicits Key Glucoregulatory Responses. Endocrinology 159:341-355
Cornelius, Ryan J; Si, Jinge; Cuevas, Catherina A et al. (2018) Renal COP9 Signalosome Deficiency Alters CUL3-KLHL3-WNK Signaling Pathway. J Am Soc Nephrol 29:2627-2640
Murillo-de-Ozores, Adrián Rafael; Rodríguez-Gama, Alejandro; Bazúa-Valenti, Silvana et al. (2018) C-terminally truncated, kidney-specific variants of the WNK4 kinase lack several sites that regulate its activity. J Biol Chem 293:12209-12221
Terker, Andrew S; Castañeda-Bueno, Maria; Ferdaus, Mohammed Z et al. (2018) With no lysine kinase 4 modulates sodium potassium 2 chloride cotransporter activity in vivo. Am J Physiol Renal Physiol 315:F781-F790
Cornelius, Ryan J; Zhang, Chong; Erspamer, Kayla J et al. (2018) Dual gain and loss of cullin 3 function mediates familial hyperkalemic hypertension. Am J Physiol Renal Physiol 315:F1006-F1018
Ellison, David H (2017) Treatment of Disorders of Sodium Balance in Chronic Kidney Disease. Adv Chronic Kidney Dis 24:332-341
Ferdaus, Mohammed Z; Miller, Lauren N; Agbor, Larry N et al. (2017) Mutant Cullin 3 causes familial hyperkalemic hypertension via dominant effects. JCI Insight 2:
Cuevas, Catherina A; Su, Xiao-Tong; Wang, Ming-Xiao et al. (2017) Potassium Sensing by Renal Distal Tubules Requires Kir4.1. J Am Soc Nephrol 28:1814-1825
Castañeda-Bueno, Maria; Arroyo, Juan Pablo; Zhang, Junhui et al. (2017) Phosphorylation by PKC and PKA regulate the kinase activity and downstream signaling of WNK4. Proc Natl Acad Sci U S A 114:E879-E886

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