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Rioux AV, Nsimba-Batomene TR, Slimani S, Bergeron NAD, Gravel MAM, Schreiber SV, Fiola MJ, Haydock L, Garneau AP, Isenring P. Navigating the multifaceted intricacies of the Na +-Cl - cotransporter, a highly regulated key effector in the control of hydromineral homeostasis. Physiol Rev 2024; 104:1147-1204. [PMID: 38329422 DOI: 10.1152/physrev.00027.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 01/01/2024] [Accepted: 02/03/2024] [Indexed: 02/09/2024] Open
Abstract
The Na+-Cl- cotransporter (NCC; SLC12A3) is a highly regulated integral membrane protein that is known to exist as three splice variants in primates. Its primary role in the kidney is to mediate the cosymport of Na+ and Cl- across the apical membrane of the distal convoluted tubule. Through this role and the involvement of other ion transport systems, NCC allows the systemic circulation to reclaim a fraction of the ultrafiltered Na+, K+, Cl-, and Mg+ loads in exchange for Ca2+ and [Formula: see text]. The physiological relevance of the Na+-Cl- cotransport mechanism in humans is illustrated by several abnormalities that result from NCC inactivation through the administration of thiazides or in the setting of hereditary disorders. The purpose of the present review is to discuss the molecular mechanisms and overall roles of Na+-Cl- cotransport as the main topics of interest. On reading the narrative proposed, one will realize that the knowledge gained in regard to these themes will continue to progress unrelentingly no matter how refined it has now become.
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Affiliation(s)
- A V Rioux
- Department of Medicine, Nephrology Research Group, Laval University, Quebec City, Quebec, Canada
| | - T R Nsimba-Batomene
- Department of Medicine, Nephrology Research Group, Laval University, Quebec City, Quebec, Canada
| | - S Slimani
- Department of Medicine, Nephrology Research Group, Laval University, Quebec City, Quebec, Canada
| | - N A D Bergeron
- Department of Medicine, Nephrology Research Group, Laval University, Quebec City, Quebec, Canada
| | - M A M Gravel
- Department of Medicine, Nephrology Research Group, Laval University, Quebec City, Quebec, Canada
| | - S V Schreiber
- Department of Medicine, Nephrology Research Group, Laval University, Quebec City, Quebec, Canada
| | - M J Fiola
- Department of Medicine, Nephrology Research Group, Laval University, Quebec City, Quebec, Canada
| | - L Haydock
- Department of Medicine, Nephrology Research Group, Laval University, Quebec City, Quebec, Canada
- Service de Néphrologie-Transplantation Rénale Adultes, Hôpital Necker-Enfants Malades, AP-HP, INSERM U1151, Université Paris Cité, Paris, France
| | - A P Garneau
- Department of Medicine, Nephrology Research Group, Laval University, Quebec City, Quebec, Canada
- Service de Néphrologie-Transplantation Rénale Adultes, Hôpital Necker-Enfants Malades, AP-HP, INSERM U1151, Université Paris Cité, Paris, France
| | - P Isenring
- Department of Medicine, Nephrology Research Group, Laval University, Quebec City, Quebec, Canada
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2
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Welling PA, Little R, Al-Qusairi L, Delpire E, Ellison DH, Fenton RA, Grimm PR. Potassium-Switch Signaling Pathway Dictates Acute Blood Pressure Response to Dietary Potassium. Hypertension 2024; 81:1044-1054. [PMID: 38465625 PMCID: PMC11023808 DOI: 10.1161/hypertensionaha.123.22546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 02/27/2024] [Indexed: 03/12/2024]
Abstract
BACKGROUND Potassium (K+)-deficient diets, typical of modern processed foods, increase blood pressure (BP) and NaCl sensitivity. A K+-dependent signaling pathway in the kidney distal convoluted tubule, coined the K+ switch, that couples extracellular K+ sensing to activation of the thiazide-sensitive NaCl cotransporter (NCC) and NaCl retention has been implicated, but causality has not been established. METHODS To test the hypothesis that small, physiological changes in plasma K+ (PK+) are translated to BP through the switch pathway, a genetic approach was used to activate the downstream switch kinase, SPAK (SPS1-related proline/alanine-rich kinase), within the distal convoluted tubule. The CA-SPAK (constitutively active SPS1-related proline/alanine-rich kinase mice) were compared with control mice over a 4-day PK+ titration (3.8-5.1 mmol) induced by changes in dietary K+. Arterial BP was monitored using radiotelemetry, and renal function measurements, NCC abundance, phosphorylation, and activity were made. RESULTS As PK+ decreased in control mice, BP progressively increased and became sensitive to dietary NaCl and hydrochlorothiazide, coincident with increased NCC phosphorylation and urinary sodium retention. By contrast, BP in CA-SPAK mice was elevated, resistant to the PK+ titration, and sensitive to hydrochlorothiazide and salt at all PK+ levels, concomitant with sustained and elevated urinary sodium retention and NCC phosphorylation and activity. Thus, genetically locking the switch on drives NaCl sensitivity and prevents the response of BP to potassium. CONCLUSIONS Low K+, common in modern ultraprocessed diets, presses the K+-switch pathway to turn on NCC activity, increasing sodium retention, BP, and salt sensitivity.
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Affiliation(s)
- Paul A. Welling
- Department of Medicine, Division of Nephrology, Johns Hopkins University School of Medicine, Baltimore, USA
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, USA
| | - Robert Little
- Department of Biomedicine, University of Aarhus, Aarhus, Denmark
| | - Lama Al-Qusairi
- Department of Medicine, Division of Nephrology, Johns Hopkins University School of Medicine, Baltimore, USA
| | - Eric Delpire
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, USA
| | - David H. Ellison
- Department of Medicine, Division of Nephrology, Oregon Health Science Center, Portland, Oregon, US
| | - Robert A. Fenton
- Department of Biomedicine, University of Aarhus, Aarhus, Denmark
| | - P. Richard Grimm
- Department of Medicine, Division of Nephrology, Johns Hopkins University School of Medicine, Baltimore, USA
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3
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Figueroa SM, Bertocchio JP, Nakamura T, El-Moghrabi S, Jaisser F, Amador CA. The Mineralocorticoid Receptor on Smooth Muscle Cells Promotes Tacrolimus-Induced Renal Injury in Mice. Pharmaceutics 2023; 15:pharmaceutics15051373. [PMID: 37242615 DOI: 10.3390/pharmaceutics15051373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Revised: 04/26/2023] [Accepted: 04/27/2023] [Indexed: 05/28/2023] Open
Abstract
Tacrolimus (Tac) is a calcineurin inhibitor commonly used as an immunosuppressor after solid organ transplantation. However, Tac may induce hypertension, nephrotoxicity, and an increase in aldosterone levels. The activation of the mineralocorticoid receptor (MR) is related to the proinflammatory status at the renal level. It modulates the vasoactive response as they are expressed on vascular smooth muscle cells (SMC). In this study, we investigated whether MR is involved in the renal damage generated by Tac and if the MR expressed in SMC is involved. Littermate control mice and mice with targeted deletion of the MR in SMC (SMC-MR-KO) were administered Tac (10 mg/Kg/d) for 10 days. Tac increased the blood pressure, plasma creatinine, expression of the renal induction of the interleukin (IL)-6 mRNA, and expression of neutrophil gelatinase-associated lipocalin (NGAL) protein, a marker of tubular damage (p < 0.05). Our study revealed that co-administration of spironolactone, an MR antagonist, or the absence of MR in SMC-MR-KO mice mitigated most of the unwanted effects of Tac. These results enhance our understanding of the involvement of MR in SMC during the adverse reactions of Tac treatment. Our findings provided an opportunity to design future studies considering the MR antagonism in transplanted subjects.
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Affiliation(s)
- Stefanny M Figueroa
- Institute of Biomedical Sciences, Universidad Autónoma de Chile, Santiago 8910060, Chile
| | - Jean-Philippe Bertocchio
- INSERM UMRS1138, Sorbonne Université, Université de Paris, Centre de Recherche des Cordeliers, 75006 Paris, France
| | - Toshifumi Nakamura
- INSERM UMRS1138, Sorbonne Université, Université de Paris, Centre de Recherche des Cordeliers, 75006 Paris, France
| | - Soumaya El-Moghrabi
- INSERM UMRS1138, Sorbonne Université, Université de Paris, Centre de Recherche des Cordeliers, 75006 Paris, France
| | - Frédéric Jaisser
- INSERM UMRS1138, Sorbonne Université, Université de Paris, Centre de Recherche des Cordeliers, 75006 Paris, France
| | - Cristián A Amador
- Faculty of Medicine and Science, Universidad San Sebastián, Santiago 7510156, Chile
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4
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Johnston JG, Welch AK, Cain BD, Sayeski PP, Gumz ML, Wingo CS. Aldosterone: Renal Action and Physiological Effects. Compr Physiol 2023; 13:4409-4491. [PMID: 36994769 DOI: 10.1002/cphy.c190043] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/31/2023]
Abstract
Aldosterone exerts profound effects on renal and cardiovascular physiology. In the kidney, aldosterone acts to preserve electrolyte and acid-base balance in response to changes in dietary sodium (Na+ ) or potassium (K+ ) intake. These physiological actions, principally through activation of mineralocorticoid receptors (MRs), have important effects particularly in patients with renal and cardiovascular disease as demonstrated by multiple clinical trials. Multiple factors, be they genetic, humoral, dietary, or otherwise, can play a role in influencing the rate of aldosterone synthesis and secretion from the adrenal cortex. Normally, aldosterone secretion and action respond to dietary Na+ intake. In the kidney, the distal nephron and collecting duct are the main targets of aldosterone and MR action, which stimulates Na+ absorption in part via the epithelial Na+ channel (ENaC), the principal channel responsible for the fine-tuning of Na+ balance. Our understanding of the regulatory factors that allow aldosterone, via multiple signaling pathways, to function properly clearly implicates this hormone as central to many pathophysiological effects that become dysfunctional in disease states. Numerous pathologies that affect blood pressure (BP), electrolyte balance, and overall cardiovascular health are due to abnormal secretion of aldosterone, mutations in MR, ENaC, or effectors and modulators of their action. Study of the mechanisms of these pathologies has allowed researchers and clinicians to create novel dietary and pharmacological targets to improve human health. This article covers the regulation of aldosterone synthesis and secretion, receptors, effector molecules, and signaling pathways that modulate its action in the kidney. We also consider the role of aldosterone in disease and the benefit of mineralocorticoid antagonists. © 2023 American Physiological Society. Compr Physiol 13:4409-4491, 2023.
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Affiliation(s)
- Jermaine G Johnston
- Division of Nephrology, Hypertension and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida, USA
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida, USA
- Nephrology Section, Veteran Administration Medical Center, North Florida/South Georgia Malcom Randall Department of Veterans Affairs Medical Center, Gainesville, Florida, USA
| | - Amanda K Welch
- Division of Nephrology, Hypertension and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida, USA
- Nephrology Section, Veteran Administration Medical Center, North Florida/South Georgia Malcom Randall Department of Veterans Affairs Medical Center, Gainesville, Florida, USA
| | - Brian D Cain
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida, USA
| | - Peter P Sayeski
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida, USA
| | - Michelle L Gumz
- Division of Nephrology, Hypertension and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida, USA
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida, USA
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida, USA
- Nephrology Section, Veteran Administration Medical Center, North Florida/South Georgia Malcom Randall Department of Veterans Affairs Medical Center, Gainesville, Florida, USA
| | - Charles S Wingo
- Division of Nephrology, Hypertension and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida, USA
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida, USA
- Nephrology Section, Veteran Administration Medical Center, North Florida/South Georgia Malcom Randall Department of Veterans Affairs Medical Center, Gainesville, Florida, USA
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5
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Johnston JG, Wingo CS. Potassium Homeostasis and WNK Kinases in the Regulation of the Sodium-Chloride Cotransporter: Hyperaldosteronism and Its Metabolic Consequences. KIDNEY360 2022; 3:1823-1828. [PMID: 36514400 PMCID: PMC9717643 DOI: 10.34067/kid.0005752022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 10/12/2022] [Indexed: 12/05/2022]
Affiliation(s)
- Jermaine G. Johnston
- Department of Medicine, University of Florida, Gainesville, Florida,Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida,Veterans Administration Medical Center, North Florida/South Georgia Veterans Health Administration, Gainesville, Florida
| | - Charles S. Wingo
- Department of Medicine, University of Florida, Gainesville, Florida,Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida,Veterans Administration Medical Center, North Florida/South Georgia Veterans Health Administration, Gainesville, Florida
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6
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Wynne BM, Samson TK, Moyer HC, van Elst HJ, Moseley AS, Hecht G, Paul O, Al-Khalili O, Gomez-Sanchez C, Ko B, Eaton DC, Hoover RS. Interleukin 6 mediated activation of the mineralocorticoid receptor in the aldosterone-sensitive distal nephron. Am J Physiol Cell Physiol 2022; 323:C1512-C1523. [PMID: 35912993 PMCID: PMC9662807 DOI: 10.1152/ajpcell.00272.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 06/28/2022] [Accepted: 07/11/2022] [Indexed: 11/22/2022]
Abstract
Hypertension is characterized by increased sodium (Na+) reabsorption along the aldosterone-sensitive distal nephron (ASDN) as well as chronic systemic inflammation. Interleukin-6 (IL-6) is thought to be a mediator of this inflammatory process. Interestingly, increased Na+ reabsorption within the ASDN does not always correlate with increases in aldosterone (Aldo), the primary hormone that modulates Na+ reabsorption via the mineralocorticoid receptor (MR). Thus, understanding how increased ASDN Na+ reabsorption may occur independent of Aldo stimulation is critical. Here, we show that IL-6 can activate the MR by activating Rac1 and stimulating the generation of reactive oxygen species (ROS) with a consequent increase in thiazide-sensitive Na+ uptake. Using an in vitro model of the distal convoluted tubule (DCT2), mDCT15 cells, we observed nuclear translocation of eGFP-tagged MR after IL-6 treatment. To confirm the activation of downstream transcription factors, mDCT15 cells were transfected with mineralocorticoid response element (MRE)-luciferase reporter constructs; then treated with vehicle, Aldo, or IL-6. Aldosterone or IL-6 treatment increased luciferase activity that was reversed with MR antagonist cotreatment, but IL-6 treatment was reversed by Rac1 inhibition or ROS reduction. In both mDCT15 and mpkCCD cells, IL-6 increased amiloride-sensitive transepithelial Na+ current. ROS and IL-6 increased 22Na+ uptake via the thiazide-sensitive sodium chloride cotransporter (NCC). These results are the first to demonstrate that IL-6 can activate the MR resulting in MRE activation and that IL-6 increases NCC-mediated Na+ reabsorption, providing evidence for an alternative mechanism for stimulating ASDN Na+ uptake during conditions where Aldo-mediated MR stimulation may not occur.
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Affiliation(s)
- Brandi M Wynne
- Department of Medicine, Nephrology, Emory University, Atlanta, Georgia
- Department of Internal Medicine, Nephrology & Hypertension, University of Utah, Salt Lake City, Utah
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah
- Immunology, Inflammation and Infectious Disease Initiative, University of Utah, Salt Lake City, Utah
| | - Trinity K Samson
- Department of Medicine, Nephrology, Emory University, Atlanta, Georgia
| | - Hayley C Moyer
- Department of Medicine, Nephrology, Emory University, Atlanta, Georgia
| | - Henrieke J van Elst
- Department of Medicine, Nephrology, Emory University, Atlanta, Georgia
- Department of Physiology, Radboud University Medical Center, Nijmegen, Netherlands
| | - Auriel S Moseley
- Department of Medicine, Nephrology, Emory University, Atlanta, Georgia
| | - Gillian Hecht
- Department of Medicine, Nephrology, Emory University, Atlanta, Georgia
| | - Oishi Paul
- Department of Medicine, Nephrology, Emory University, Atlanta, Georgia
| | - Otor Al-Khalili
- Department of Medicine, Nephrology, Emory University, Atlanta, Georgia
| | - Celso Gomez-Sanchez
- G.V. (Sonny) Montgomery VA Medical Center, Jackson, Mississippi
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Mississippi
| | - Benjamin Ko
- Department of Medicine, Nephrology, University of Chicago, Chicago, Illinois
| | - Douglas C Eaton
- Department of Medicine, Nephrology, Emory University, Atlanta, Georgia
| | - Robert S Hoover
- Department of Medicine, Nephrology, Emory University, Atlanta, Georgia
- Research Service, Atlanta Veterans Affairs Medical Center, Atlanta, Georgia
- Section of Nephrology and Hypertension, Deming Department of Medicine, Tulane University, New Orleans, Louisiana
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7
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Urinary extracellular vesicle mRNA analysis of sodium chloride cotransporter in hypertensive patients under different conditions. J Hum Hypertens 2022:10.1038/s41371-022-00744-3. [PMID: 35978099 DOI: 10.1038/s41371-022-00744-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 07/19/2022] [Accepted: 07/27/2022] [Indexed: 11/09/2022]
Abstract
Urinary extracellular vesicles (UEV) mainly derive from cells of the urogenital tract and their cargo (proteins, nucleic acids, lipids, etc.) reflects their cells of origin. Na chloride cotransporter (NCC) is expressed at the kidney level in the distal convoluted tubule, is involved in salt reabsorption, and is the target of the diuretic thiazides. NCC protein has been recognized and quantified in UEV in previous studies; however, UEV NCC mRNA has never been studied. This study aimed to identify and analyze NCC mRNA levels in primary aldosteronism (PA). The rationale for this investigation stems from previous observations regarding NCC (protein) as a possible biomarker for the diagnosis of PA. To evaluate modulations in the expression of NCC, we analyzed NCC mRNA levels in UEV in PA and essential hypertensive (EH) patients under different conditions, that is, before and after saline infusion, anti-aldosterone pharmacological treatment, and adrenal surgery. NCC mRNA was measured by RT-qPCR in all the samples and was regulated by volume expansion. Its response to mineralocorticoid receptor antagonist was correlated with renin, and it was increased in PA patients after adrenalectomy. NCC mRNA is evaluable in UEV and it can provide insights into the pathophysiology of distal convolute tubule in different clinical conditions including PA.
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8
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Kristensen M, Fenton RA, Poulsen SB. Dissecting the Effects of Aldosterone and Hypokalemia on the Epithelial Na + Channel and the NaCl Cotransporter. Front Physiol 2022; 13:800055. [PMID: 35557966 PMCID: PMC9086401 DOI: 10.3389/fphys.2022.800055] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 03/31/2022] [Indexed: 11/13/2022] Open
Abstract
Primary hyperaldosteronism (PA) is characterized by aldosterone excess and hypertension. This may be linked to increased renal Na+ reabsorption via the epithelial Na+ channel (ENaC) and the NaCl cotransporter (NCC). The majority of PA patients have normal plasma K+ levels, but a subset of cases are associated with hypokalemia. High NCC levels observed in long-term studies with aldosterone-infused rodents have been attributed to direct effects of aldosterone. Aldosterone can also increase active phosphorylated NCC (pT58-NCC) acutely. However, direct effects of aldosterone on NCC have been contested by recent studies indicating that it is rather an indirect effect of hypokalemia. We therefore set out to determine isolated long-term aldosterone and K+ effects on ENaC and NCC using various in vivo and ex vivo approaches. In mice, aldosterone-induced hypokalemia was prevented by simultaneous amiloride infusion, coupled to increased cleavage of α- and γENaC but no effect on NCC. Regression analyses of in vivo data showed a positive correlation between aldosterone/K+ and αENaC but a negative correlation with NCC and pT58-NCC. Ex vivo, exposure of kidney tubules for 21 h to aldosterone increased cleavage of αENaC and γENaC, but no effects were observed on NCC or pT58-NCC. Exposure of tubules to low K+ media reduced αENaC but increased NCC and pT58-NCC. As hypokalemia can enhance cell proliferation markers in the distal convoluted tubule (DCT), we hypothesized that aldosterone infusion would increase proliferating cell nuclear antigen (PCNA) expression. Infusion of aldosterone in mice for 6 days greatly increased PCNA expression in the DCT. Collectively, in vivo and ex vivo data suggest that both aldosterone and K+ can increase ENaC directly. In contrast, the observed increase in abundance and phosphorylation of NCC in aldosterone-infused mice is likely an indirect effect of enhanced ENaC-mediated K+ secretion and subsequent hypokalemia. Thus, it is possible that NCC may only be increased in PA when the condition is associated with hypokalemia.
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Affiliation(s)
| | - Robert A Fenton
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Søren B Poulsen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
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9
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Douma LG, Costello HM, Crislip GR, Cheng KY, Lynch IJ, Juffre A, Barral D, Masten S, Roig E, Beguiristain K, Li W, Bratanatawira P, Wingo CS, Gumz ML. Kidney-specific KO of the circadian clock protein PER1 alters renal Na + handling, aldosterone levels, and kidney/adrenal gene expression. Am J Physiol Renal Physiol 2022; 322:F449-F459. [PMID: 35129370 PMCID: PMC9169971 DOI: 10.1152/ajprenal.00385.2021] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 01/20/2022] [Accepted: 01/28/2022] [Indexed: 11/22/2022] Open
Abstract
PERIOD 1 (PER1) is a circadian clock transcription factor that is regulated by aldosterone, a hormone that increases blood volume and Na+ retention to increase blood pressure. Male global Per1 knockout (KO) mice develop reduced night/day differences in Na+ excretion in response to a high-salt diet plus desoxycorticosterone pivalate treatment (HS + DOCP), a model of salt-sensitive hypertension. In addition, global Per1 KO mice exhibit higher aldosterone levels on a normal-salt diet. To determine the role of Per1 in the kidney, male kidney-specific Per1 KO (KS-Per1 KO) mice were generated using Ksp-cadherin Cre recombinase to remove exons 2-8 of Per1 in the distal nephron and collecting duct. Male KS-Per1 KO mice have increased Na+ retention but have normal diurnal differences in Na+ excretion in response to HS + DOCP. The increased Na+ retention is associated with altered expression of glucocorticoid and mineralocorticoid receptors, increased serum aldosterone, and increased medullary endothelin-1 compared with control mice. Adrenal gland gene expression analysis revealed that circadian clock and aldosterone synthesis genes have altered expression in KS-Per1 KO mice compared with control mice. These results emphasize the importance of the circadian clock not only in maintaining rhythms of physiological functions but also for adaptability in response to environmental cues, such as HS + DOCP, to maintain overall homeostasis. Given the prevalence of salt-sensitive hypertension in the general population, these findings have important implications for our understanding of how circadian clock proteins regulate homeostasis.NEW & NOTEWORTHY For the first time, we show that knockout of the circadian clock transcription factor PERIOD 1 using kidney-specific cadherin Cre results in increased renal Na+ reabsorption, increased aldosterone levels, and changes in gene expression in both the kidney and adrenal gland. Diurnal changes in renal Na+ excretion were not observed, demonstrating that the clock protein PER1 in the kidney is important for maintaining homeostasis and that this effect may be independent of time of day.
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Affiliation(s)
- Lauren G Douma
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida
- Division of Nephrology, Hypertension, and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida
| | - Hannah M Costello
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida
- Division of Nephrology, Hypertension, and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida
| | - G Ryan Crislip
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida
- Division of Nephrology, Hypertension, and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida
| | - Kit-Yan Cheng
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida
- Division of Nephrology, Hypertension, and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida
| | - I Jeanette Lynch
- Division of Nephrology, Hypertension, and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida
- North Florida/South Georgia Malcolm Randall Veterans Affairs Medical Center, Gainesville, Florida
| | - Alexandria Juffre
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida
- Division of Nephrology, Hypertension, and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida
| | - Dominique Barral
- Division of Nephrology, Hypertension, and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida
| | - Sarah Masten
- Division of Nephrology, Hypertension, and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida
| | - Emilio Roig
- Division of Nephrology, Hypertension, and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida
| | - Kevin Beguiristain
- Division of Nephrology, Hypertension, and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida
| | - Wendy Li
- Division of Nephrology, Hypertension, and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida
| | - Phillip Bratanatawira
- Division of Nephrology, Hypertension, and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida
| | - Charles S Wingo
- Division of Nephrology, Hypertension, and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida
- North Florida/South Georgia Malcolm Randall Veterans Affairs Medical Center, Gainesville, Florida
| | - Michelle L Gumz
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida
- Division of Nephrology, Hypertension, and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida
- Center for Integrative Cardiovascular and Metabolic Diseases, University of Florida, Gainesville, Florida
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10
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Franken GAC, Adella A, Bindels RJM, Baaij JHF. Mechanisms coupling sodium and magnesium reabsorption in the distal convoluted tubule of the kidney. Acta Physiol (Oxf) 2021; 231:e13528. [PMID: 32603001 PMCID: PMC7816272 DOI: 10.1111/apha.13528] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 05/29/2020] [Accepted: 06/22/2020] [Indexed: 02/06/2023]
Abstract
Hypomagnesaemia is a common feature of renal Na+ wasting disorders such as Gitelman and EAST/SeSAME syndrome. These genetic defects specifically affect Na+ reabsorption in the distal convoluted tubule, where Mg2+ reabsorption is tightly regulated. Apical uptake via TRPM6 Mg2+ channels and basolateral Mg2+ extrusion via a putative Na+ -Mg2+ exchanger determines Mg2+ reabsorption in the distal convoluted tubule. However, the mechanisms that explain the high incidence of hypomagnesaemia in patients with Na+ wasting disorders of the distal convoluted tubule are largely unknown. In this review, we describe three potential mechanisms by which Mg2+ reabsorption in the distal convoluted tubule is linked to Na+ reabsorption. First, decreased activity of the thiazide-sensitive Na+ /Cl- cotransporter (NCC) results in shortening of the segment, reducing the Mg2+ reabsorption capacity. Second, the activity of TRPM6 and NCC are determined by common regulatory pathways. Secondary effects of NCC dysregulation such as hormonal imbalance, therefore, might disturb TRPM6 expression. Third, the basolateral membrane potential, maintained by the K+ permeability and Na+ -K+ -ATPase activity, provides the driving force for Na+ and Mg2+ extrusion. Depolarisation of the basolateral membrane potential in Na+ wasting disorders of the distal convoluted tubule may therefore lead to reduced activity of the putative Na+ -Mg2+ exchanger SLC41A1. Elucidating the interconnections between Mg2+ and Na+ transport in the distal convoluted tubule is hampered by the currently available models. Our analysis indicates that the coupling of Na+ and Mg2+ reabsorption may be multifactorial and that advanced experimental models are required to study the molecular mechanisms.
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Affiliation(s)
- Gijs A. C. Franken
- Department of Physiology Radboud Institute for Molecular Life SciencesRadboud University Medical Center Nijmegen the Netherlands
| | - Anastasia Adella
- Department of Physiology Radboud Institute for Molecular Life SciencesRadboud University Medical Center Nijmegen the Netherlands
| | - René J. M. Bindels
- Department of Physiology Radboud Institute for Molecular Life SciencesRadboud University Medical Center Nijmegen the Netherlands
| | - Jeroen H. F. Baaij
- Department of Physiology Radboud Institute for Molecular Life SciencesRadboud University Medical Center Nijmegen the Netherlands
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11
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Song C, Yue Q, Moseley A, Al-Khalili O, Wynne BM, Ma H, Wang L, Eaton DC. Myristoylated alanine-rich C kinase substrate-like protein-1 regulates epithelial sodium channel activity in renal distal convoluted tubule cells. Am J Physiol Cell Physiol 2020; 319:C589-C604. [PMID: 32639874 DOI: 10.1152/ajpcell.00218.2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The epithelial sodium channel (ENaC) regulates blood pressure by fine-tuning distal nephron sodium reabsorption. Our previous work has shown that ENaC gating is regulated by anionic phospholipid phosphates, including phosphatidylinositol 4,5-bisphosphate (PIP2). The PIP2-dependent regulation of ENaC is mediated by the myristoylated alanine-rich protein kinase C substrate-like protein-1 (MLP-1). MLP-1 binds to and is a reversible source of PIP2 at the plasma membrane. We examined MLP-1 regulation of ENaC in distal convoluted tubule clonal cell line DCT-15 cells. Wild-type MLP-1 runs at an apparent molecular mass of 52 kDa despite having a predicted molecular mass of 21 kDa. Native MLP-1 consists of several distinct structural elements: an effector domain that is highly positively charged, sequesters PIP2, contains serines that are the target of PKC, and controls MLP-1 association with the membrane; a myristoylation domain that promotes association with the membrane; and a multiple homology 2 domain of previously unknown function. To further examine MLP-1 in DCT-15 cells, we constructed several MLP-1 mutants: WT, a full-length wild-type protein; S3A, three substitutions in the effector domain to prevent phosphorylation; S3D mimicked constitutive phosphorylation by replacing three serines with aspartates; and GA replaced the myristoylation site glycine with alanine, so GA could not be myristoylated. Each mutant was tagged with either NH2-terminal 3XFLAG or COOH-terminal mCherry or V5. Transfection with MLP mutants modified ENaC activity in DCT-15 cells: activity was highest in S3A and lowest in S3D, and the activity after transfection with either construct was significantly different from WT. In Western blots, when transfected with 3XFLAG-tagged MLP-1 mutants, the expression of the full length of MLP-1 at 52 kDa increased in mutant S3A-MLP-1-transfected DCT-15 cells and decreased in S3D-MLP-1-transfected DCT-15 cells. Several lower molecular mass bands were also detected that correspond to potential presumptive calpain cleavage products. Confocal imaging shows that the different mutants localize in different subcellular compartments consistent with their preferred location in the membrane or in the cytosol. Activation of protein kinase C increases phosphorylation of endogenous MLP-1 and reduces ENaC activity. Our results suggest a complicated role for proteolytic processing in MLP-1 regulation of ENaC.
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Affiliation(s)
- Chang Song
- Department of Neurology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China.,Division of Nephrology, Department of Medicine, Emory University, Atlanta, Georgia.,Department of Physiology, Emory University, Atlanta, Georgia
| | - Qiang Yue
- Division of Nephrology, Department of Medicine, Emory University, Atlanta, Georgia
| | - Auriel Moseley
- Division of Nephrology, Department of Medicine, Emory University, Atlanta, Georgia
| | - Otor Al-Khalili
- Division of Nephrology, Department of Medicine, Emory University, Atlanta, Georgia
| | - Brandi M Wynne
- Division of Nephrology & Hypertension, Department of Internal Medicine, University of Utah, Salt Lake City, Utah
| | - Heping Ma
- Department of Physiology, Emory University, Atlanta, Georgia
| | - Lihua Wang
- Department of Neurology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Douglas C Eaton
- Division of Nephrology, Department of Medicine, Emory University, Atlanta, Georgia
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12
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Arginine Vasopressin Modulates Ion and Acid/Base Balance by Regulating Cell Numbers of Sodium Chloride Cotransporter and H +-ATPase Rich Ionocytes. Int J Mol Sci 2020; 21:ijms21113957. [PMID: 32486459 PMCID: PMC7312464 DOI: 10.3390/ijms21113957] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 05/26/2020] [Accepted: 05/30/2020] [Indexed: 01/14/2023] Open
Abstract
Arginine vasopressin (Avp) is a conserved pleiotropic hormone that is known to regulate both water reabsorption and ion balance; however, many of the mechanisms underlying its effects remain unclear. Here, we used zebrafish embryos to investigate how Avp modulates ion and acid–base homeostasis. After incubating embryos in double-deionized water for 24 h, avp mRNA expression levels were significantly upregulated. Knockdown of Avp protein expression by an antisense morpholino oligonucleotide (MO) reduced the expression of ionocyte-related genes and downregulated whole-body Cl− content and H+ secretion, while Na+ and Ca2+ levels were not affected. Incubation of Avp antagonist SR49059 also downregulated the mRNA expression of sodium chloride cotransporter 2b (ncc2b), which is a transporter responsible for Cl− uptake. Correspondingly, avp morphants showed lower NCC and H+-ATPase rich (HR) cell numbers, but Na+/K+-ATPase rich (NaR) cell numbers remained unchanged. avp MO also downregulated the numbers of foxi3a- and p63-expressing cells. Finally, the mRNA expression levels of calcitonin gene-related peptide (cgrp) and its receptor, calcitonin receptor-like 1 (crlr1), were downregulated in avp morphants, suggesting that Avp might affect Cgrp and Crlr1 for modulating Cl− balance. Together, our results reveal a molecular/cellular pathway through which Avp regulates ion and acid–base balance, providing new insights into its function.
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13
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Hunter RW, Bailey MA. Hyperkalemia: pathophysiology, risk factors and consequences. Nephrol Dial Transplant 2020; 34:iii2-iii11. [PMID: 31800080 PMCID: PMC6892421 DOI: 10.1093/ndt/gfz206] [Citation(s) in RCA: 85] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Indexed: 12/13/2022] Open
Abstract
There have been significant recent advances in our understanding of the mechanisms that maintain potassium homoeostasis and the clinical consequences of hyperkalemia. In this article we discuss these advances within a concise review of the pathophysiology, risk factors and consequences of hyperkalemia. We highlight aspects that are of particular relevance for clinical practice. Hyperkalemia occurs when renal potassium excretion is limited by reductions in glomerular filtration rate, tubular flow, distal sodium delivery or the expression of aldosterone-sensitive ion transporters in the distal nephron. Accordingly, the major risk factors for hyperkalemia are renal failure, diabetes mellitus, adrenal disease and the use of angiotensin-converting enzyme inhibitors, angiotensin receptor blockers or potassium-sparing diuretics. Hyperkalemia is associated with an increased risk of death, and this is only in part explicable by hyperkalemia-induced cardiac arrhythmia. In addition to its well-established effects on cardiac excitability, hyperkalemia could also contribute to peripheral neuropathy and cause renal tubular acidosis. Hyperkalemia-or the fear of hyperkalemia-contributes to the underprescription of potentially beneficial medications, particularly in heart failure. The newer potassium binders could play a role in attempts to minimize reduced prescribing of renin-angiotensin inhibitors and mineraolocorticoid antagonists in this context.
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Affiliation(s)
- Robert W Hunter
- British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute, Edinburgh BioQuarter, Edinburgh, UK
| | - Matthew A Bailey
- British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute, Edinburgh BioQuarter, Edinburgh, UK
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14
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Hoorn EJ, Gritter M, Cuevas CA, Fenton RA. Regulation of the Renal NaCl Cotransporter and Its Role in Potassium Homeostasis. Physiol Rev 2020; 100:321-356. [DOI: 10.1152/physrev.00044.2018] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Daily dietary potassium (K+) intake may be as large as the extracellular K+ pool. To avoid acute hyperkalemia, rapid removal of K+ from the extracellular space is essential. This is achieved by translocating K+ into cells and increasing urinary K+ excretion. Emerging data now indicate that the renal thiazide-sensitive NaCl cotransporter (NCC) is critically involved in this homeostatic kaliuretic response. This suggests that the early distal convoluted tubule (DCT) is a K+ sensor that can modify sodium (Na+) delivery to downstream segments to promote or limit K+ secretion. K+ sensing is mediated by the basolateral K+ channels Kir4.1/5.1, a capacity that the DCT likely shares with other nephron segments. Thus, next to K+-induced aldosterone secretion, K+ sensing by renal epithelial cells represents a second feedback mechanism to control K+ balance. NCC’s role in K+ homeostasis has both physiological and pathophysiological implications. During hypovolemia, NCC activation by the renin-angiotensin system stimulates Na+ reabsorption while preventing K+ secretion. Conversely, NCC inactivation by high dietary K+ intake maximizes kaliuresis and limits Na+ retention, despite high aldosterone levels. NCC activation by a low-K+ diet contributes to salt-sensitive hypertension. K+-induced natriuresis through NCC offers a novel explanation for the antihypertensive effects of a high-K+ diet. A possible role for K+ in chronic kidney disease is also emerging, as epidemiological data reveal associations between higher urinary K+ excretion and improved renal outcomes. This comprehensive review will embed these novel insights on NCC regulation into existing concepts of K+ homeostasis in health and disease.
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Affiliation(s)
- Ewout J. Hoorn
- Department of Internal Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands; and Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Martin Gritter
- Department of Internal Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands; and Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Catherina A. Cuevas
- Department of Internal Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands; and Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Robert A. Fenton
- Department of Internal Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands; and Department of Biomedicine, Aarhus University, Aarhus, Denmark
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15
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Lee HW, Harris AN, Romero MF, Welling PA, Wingo CS, Verlander JW, Weiner ID. NBCe1-A is required for the renal ammonia and K + response to hypokalemia. Am J Physiol Renal Physiol 2019; 318:F402-F421. [PMID: 31841393 DOI: 10.1152/ajprenal.00481.2019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Hypokalemia increases ammonia excretion and decreases K+ excretion. The present study examined the role of the proximal tubule protein NBCe1-A in these responses. We studied mice with Na+-bicarbonate cotransporter electrogenic, isoform 1, splice variant A (NBCe1-A) deletion [knockout (KO) mice] and their wild-type (WT) littermates were provided either K+ control or K+-free diet. We also used tissue sections to determine the effect of extracellular ammonia on NaCl cotransporter (NCC) phosphorylation. The K+-free diet significantly increased proximal tubule NBCe1-A and ammonia excretion in WT mice, and NBCe1-A deletion blunted the ammonia excretion response. NBCe1-A deletion inhibited the ammoniagenic/ammonia recycling enzyme response in the cortical proximal tubule (PT), where NBCe1-A is present in WT mice. In the outer medulla, where NBCe1-A is not present, the PT ammonia metabolism response was accentuated by NBCe1-A deletion. KO mice developed more severe hypokalemia and had greater urinary K+ excretion during the K+-free diet than did WT mice. This was associated with blunting of the hypokalemia-induced change in NCC phosphorylation. NBCe1-A KO mice have systemic metabolic acidosis, but experimentally induced metabolic acidosis did not alter NCC phosphorylation. Although KO mice have impaired ammonia metabolism, experiments in tissue sections showed that lack of ammonia does impair NCC phosphorylation. Finally, urinary aldosterone was greater in KO mice than in WT mice, but neither expression of epithelial Na+ channel α-, β-, and γ-subunits nor of H+-K+-ATPase α1- or α2-subunits correlated with changes in urinary K+. We conclude that NBCe1-A is critical for the effect of diet-induced hypokalemia to increase cortical proximal tubule ammonia generation and for the expected decrease in urinary K+ excretion.
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Affiliation(s)
- Hyun-Wook Lee
- Division of Nephrology, Hypertension and Renal Transplantation, University of Florida College of Medicine, Gainesville, Florida
| | - Autumn N Harris
- Division of Nephrology, Hypertension and Renal Transplantation, University of Florida College of Medicine, Gainesville, Florida
| | - Michael F Romero
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
| | - Paul A Welling
- Nephrology Division, Departments of Medicine and Physiology, Johns Hopkins Medical School, Baltimore, Maryland
| | - Charles S Wingo
- Division of Nephrology, Hypertension and Renal Transplantation, University of Florida College of Medicine, Gainesville, Florida.,Nephrology and Hypertension Section, Gainesville Veterans Affairs Medical Center, Gainesville, Florida
| | - Jill W Verlander
- Division of Nephrology, Hypertension and Renal Transplantation, University of Florida College of Medicine, Gainesville, Florida
| | - I David Weiner
- Division of Nephrology, Hypertension and Renal Transplantation, University of Florida College of Medicine, Gainesville, Florida.,Nephrology and Hypertension Section, Gainesville Veterans Affairs Medical Center, Gainesville, Florida
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16
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Poulsen SB, Fenton RA. K
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and the renin–angiotensin–aldosterone system: new insights into their role in blood pressure control and hypertension treatment. J Physiol 2019; 597:4451-4464. [DOI: 10.1113/jp276844] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 05/17/2019] [Indexed: 12/11/2022] Open
Affiliation(s)
- Søren B. Poulsen
- Department of BiomedicineAarhus University Aarhus DK‐8000 Denmark
| | - Robert A. Fenton
- Department of BiomedicineAarhus University Aarhus DK‐8000 Denmark
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17
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Cheng L, Poulsen SB, Wu Q, Esteva-Font C, Olesen ETB, Peng L, Olde B, Leeb-Lundberg LMF, Pisitkun T, Rieg T, Dimke H, Fenton RA. Rapid Aldosterone-Mediated Signaling in the DCT Increases Activity of the Thiazide-Sensitive NaCl Cotransporter. J Am Soc Nephrol 2019; 30:1454-1470. [PMID: 31253651 DOI: 10.1681/asn.2018101025] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 04/29/2019] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND The NaCl cotransporter NCC in the kidney distal convoluted tubule (DCT) regulates urinary NaCl excretion and BP. Aldosterone increases NaCl reabsorption via NCC over the long-term by altering gene expression. But the acute effects of aldosterone in the DCT are less well understood. METHODS Proteomics, bioinformatics, and cell biology approaches were combined with animal models and gene-targeted mice. RESULTS Aldosterone significantly increases NCC activity within minutes in vivo or ex vivo. These effects were independent of transcription and translation, but were absent in the presence of high potassium. In vitro, aldosterone rapidly increased intracellular cAMP and inositol phosphate accumulation, and altered phosphorylation of various kinases/kinase substrates within the MAPK/ERK, PI3K/AKT, and cAMP/PKA pathways. Inhibiting GPR30, a membrane-associated receptor, limited aldosterone's effects on NCC activity ex vivo, and NCC phosphorylation was reduced in GPR30 knockout mice. Phosphoproteomics, network analysis, and in vitro studies determined that aldosterone activates EGFR-dependent signaling. The EGFR immunolocalized to the DCT and EGFR tyrosine kinase inhibition decreased NCC activity ex vivo and in vivo. CONCLUSIONS Aldosterone acutely activates NCC to modulate renal NaCl excretion.
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Affiliation(s)
- Lei Cheng
- InterPrET Center, Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | | | - Qi Wu
- InterPrET Center, Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | | | - Emma T B Olesen
- InterPrET Center, Department of Biomedicine, Aarhus University, Aarhus, Denmark.,Faculty of Health and Medical Sciences, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Li Peng
- InterPrET Center, Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Björn Olde
- Unit of Drug Target Discovery, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - L M Fredrik Leeb-Lundberg
- Unit of Drug Target Discovery, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Trairak Pisitkun
- InterPrET Center, Department of Biomedicine, Aarhus University, Aarhus, Denmark.,Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Timo Rieg
- Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida
| | - Henrik Dimke
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark; and.,Department of Nephrology, Odense University Hospital, Odense, Denmark
| | - Robert A Fenton
- InterPrET Center, Department of Biomedicine, Aarhus University, Aarhus, Denmark;
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18
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The interplay of renal potassium and sodium handling in blood pressure regulation: critical role of the WNK-SPAK-NCC pathway. J Hum Hypertens 2019; 33:508-523. [DOI: 10.1038/s41371-019-0170-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Revised: 12/18/2018] [Accepted: 01/03/2019] [Indexed: 12/19/2022]
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19
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Wang YF, Lafont AG, Lee YC, Hwang PP. A novel function of calcitonin gene-related peptide in body fluid Cl- homeostasis. Proc Biol Sci 2017; 283:rspb.2016.0684. [PMID: 27306053 DOI: 10.1098/rspb.2016.0684] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 05/18/2016] [Indexed: 12/15/2022] Open
Abstract
Vertebrates need to maintain extracellular chloride (Cl(-)) concentrations to ensure the normal operation of physiological processes; the transition from aquatic to terrestrial environments necessitated the development of sophisticated mechanisms to ensure Cl(-) homeostasis in the face of fluctuating Cl(-) levels. Zebrafish calcitonin gene-related peptide (CGRP), unlike its splice variant calcitonin, does not respond to environmental Ca(2+) levels. This study aimed to test the hypothesis that CGRP is involved in the control of body fluid Cl(-) homeostasis. Acclimation to high-Cl(-) artificial water stimulated the mRNA expression of cgrp and the receptor (crlr1) when compared with low-Cl(-) CGRP knockdown induced upregulation of the Na(+)-Cl(-) co-transporter (ncc2b), while overexpression of CGRP resulted in the downregulation of ncc2b mRNA synthesis and a simultaneous decrease in Cl(-) uptake in embryos. Consistent with these findings, knockdown of either cgrp or crlr1 was found to increase the density of NCC2b-expressing cells in embryos. This is the first demonstration that CGRP acts as a hypochloremic hormone through suppressing NCC2b expression and the differentiation of NCC-expressing ionocytes. Elucidation of this novel function of CGRP in fish body fluid Cl(-) homeostasis promises to enhance our understanding of the related physiology in vertebrates.
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Affiliation(s)
- Yi-Fang Wang
- Institute of Fishery Science, National Taiwan University, Taipei, Taiwan Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Anne-Gaëlle Lafont
- Muséum National d'Histoire Naturelle, Sorbonne Universités, Research Unit BOREA, Biology of Aquatic Organisms and Ecosystems, CNRS 7208, IRD207, UPMC, UCBN, Paris, France
| | - Yi-Chun Lee
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Pung-Pung Hwang
- Institute of Fishery Science, National Taiwan University, Taipei, Taiwan Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
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20
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Erben RG, Andrukhova O. FGF23-Klotho signaling axis in the kidney. Bone 2017; 100:62-68. [PMID: 27622885 DOI: 10.1016/j.bone.2016.09.010] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2016] [Revised: 09/08/2016] [Accepted: 09/09/2016] [Indexed: 01/04/2023]
Abstract
Fibroblast growth factor-23 (FGF23) is a bone-derived hormone protecting against the potentially deleterious effects of hyperphosphatemia by suppression of phosphate reabsorption and of active vitamin D hormone synthesis in the kidney. The kidney is one of the main target organs of FGF23 signaling. The purpose of this review is to highlight the recent advances in the area of FGF23-Klotho signaling in the kidney. During recent years, it has become clear that FGF23 acts independently on proximal and distal tubular epithelium. In proximal renal tubules, FGF23 suppresses phosphate reabsorption by a Klotho dependent activation of extracellular signal-regulated kinase-1/2 (ERK1/2) and of serum/glucocorticoid-regulated kinase-1 (SGK1), leading to phosphorylation of the scaffolding protein Na+/H+ exchange regulatory cofactor (NHERF)-1 and subsequent internalization and degradation of sodium-phosphate cotransporters. In distal renal tubules, FGF23 augments calcium and sodium reabsorption by increasing the apical membrane expression of the epithelial calcium channel TRPV5 and of the sodium-chloride cotransporter NCC through a Klotho dependent activation of with-no-lysine kinase-4 (WNK4). In proximal and distal renal tubules, FGF receptor-1 is probably the dominant FGF receptor mediating the effects of FGF23 by forming a complex with membrane-bound Klotho in the basolateral membrane. The newly described sodium- and calcium-conserving functions of FGF23 may have major implications for the pathophysiology of diseases characterized by chronically increased circulating FGF23 concentrations such as chronic kidney disease.
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21
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Boscardin E, Perrier R, Sergi C, Maillard M, Loffing J, Loffing-Cueni D, Koesters R, Rossier BC, Hummler E. Severe hyperkalemia is rescued by low-potassium diet in renal βENaC-deficient mice. Pflugers Arch 2017; 469:1387-1399. [DOI: 10.1007/s00424-017-1990-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 04/07/2017] [Accepted: 04/26/2017] [Indexed: 12/31/2022]
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22
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Molina-Jijón E, Rodríguez-Muñoz R, González-Ramírez R, Namorado-Tónix C, Pedraza-Chaverri J, Reyes JL. Aldosterone signaling regulates the over-expression of claudin-4 and -8 at the distal nephron from type 1 diabetic rats. PLoS One 2017; 12:e0177362. [PMID: 28493961 PMCID: PMC5426686 DOI: 10.1371/journal.pone.0177362] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 04/17/2017] [Indexed: 12/19/2022] Open
Abstract
Hyperglycemia in diabetes alters tight junction (TJ) proteins in the kidney. We evaluated the participation of aldosterone (ALD), and the effect of spironolactone (SPL), a mineralocorticoid receptor antagonist, on the expressions of claudin-2, -4, -5 and -8, and occludin in glomeruli, proximal and distal tubules isolated from diabetic rats. Type 1 diabetes was induced in female Wistar rats by a single tail vein injection of streptozotocin (STZ), and SPL was administrated daily by gavage, from days 3–21. Twenty-one days after STZ injection the rats were sacrificed. In diabetic rats, the serum ALD levels were increased, and SPL-treatment did not have effect on these levels or in hyperglycemia, however, proteinuria decreased in SPL-treated diabetic rats. Glomerular damage, evaluated by nephrin and Wilm’s tumor 1 (WT1) protein expressions, and proximal tubular damage, evaluated by kidney injury molecule 1 (Kim-1) and heat shock protein 72 kDa (Hsp72) expressions, were ameliorated by SPL. Also, SPL prevented decrement in claudin-5 in glomeruli, and claudin-2 and occludin in proximal tubules by decreasing oxidative stress, evaluated by superoxide anion (O2●―) production, and oxidative stress markers. In distal tubules, SPL ameliorated increase in mRNA, protein expression, and phosphorylation in threonine residues of claudin-4 and -8, through a serum and glucocorticoid-induced kinase 1 (SGK1), and with-no-lysine kinase 4 (WNK4) signaling pathway. In conclusion, this is the first study that demonstrates that ALD modulates the expression of renal TJ proteins in diabetes, and that the blockade of its actions with SPL, may be a promising therapeutic strategy to prevent alterations of TJ proteins in diabetic nephropathy.
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MESH Headings
- Aldosterone/metabolism
- Animals
- Claudin-4/metabolism
- Claudins/metabolism
- Diabetes Mellitus, Experimental/blood
- Diabetes Mellitus, Experimental/complications
- Diabetes Mellitus, Experimental/metabolism
- Diabetes Mellitus, Experimental/pathology
- Diabetes Mellitus, Type 1/blood
- Diabetes Mellitus, Type 1/complications
- Diabetes Mellitus, Type 1/metabolism
- Diabetes Mellitus, Type 1/pathology
- Female
- Hyperglycemia/blood
- Hyperglycemia/drug therapy
- Hyperglycemia/prevention & control
- Immediate-Early Proteins/metabolism
- Kidney Glomerulus/drug effects
- Kidney Glomerulus/pathology
- Kidney Tubules/drug effects
- Kidney Tubules/pathology
- Models, Biological
- Natriuresis/drug effects
- Nephrons/metabolism
- Oxidative Stress/drug effects
- Phosphorylation/drug effects
- Potassium/blood
- Protein Serine-Threonine Kinases/metabolism
- Proteinuria/blood
- Proteinuria/complications
- Proteinuria/drug therapy
- Proteinuria/prevention & control
- Rats, Wistar
- Signal Transduction/drug effects
- Spironolactone/pharmacology
- Spironolactone/therapeutic use
- Tight Junctions/drug effects
- Tight Junctions/metabolism
- Weight Loss/drug effects
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Affiliation(s)
- Eduardo Molina-Jijón
- Department of Physiology, Biophysics and Neuroscience, Center for Research and Advanced Studies of the National Polytechnic Institute (CINVESTAV-IPN), Mexico City, México
- Departamento de Biociencias e Ingeniería, Centro Interdisciplinario de Investigaciones y Estudios sobre el Medio Ambiente y Desarrollo del Instituto Politécnico Nacional (CIIEMAD-IPN), Mexico City, México
| | - Rafael Rodríguez-Muñoz
- Department of Physiology, Biophysics and Neuroscience, Center for Research and Advanced Studies of the National Polytechnic Institute (CINVESTAV-IPN), Mexico City, México
| | - Ricardo González-Ramírez
- Department of Molecular Biology and Histocompatibility, Dr. Manuel Gea González, General Hospital, Mexico City, México
| | - Carmen Namorado-Tónix
- Department of Physiology, Biophysics and Neuroscience, Center for Research and Advanced Studies of the National Polytechnic Institute (CINVESTAV-IPN), Mexico City, México
| | - José Pedraza-Chaverri
- Department of Biology, Faculty of Chemistry, National Autonomous University of Mexico (UNAM), Mexico City, México
| | - Jose L. Reyes
- Department of Physiology, Biophysics and Neuroscience, Center for Research and Advanced Studies of the National Polytechnic Institute (CINVESTAV-IPN), Mexico City, México
- * E-mail:
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23
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Ong GSY, Young MJ. Mineralocorticoid regulation of cell function: the role of rapid signalling and gene transcription pathways. J Mol Endocrinol 2017; 58:R33-R57. [PMID: 27821439 DOI: 10.1530/jme-15-0318] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 11/06/2016] [Indexed: 12/22/2022]
Abstract
The mineralocorticoid receptor (MR) and mineralocorticoids regulate epithelial handling of electrolytes, and induces diverse effects on other tissues. Traditionally, the effects of MR were ascribed to ligand-receptor binding and activation of gene transcription. However, the MR also utilises a number of intracellular signalling cascades, often by transactivating unrelated receptors, to change cell function more rapidly. Although aldosterone is the physiological mineralocorticoid, it is not the sole ligand for MR. Tissue-selective and mineralocorticoid-specific effects are conferred through the enzyme 11β-hydroxysteroid dehydrogenase 2, cellular redox status and properties of the MR itself. Furthermore, not all aldosterone effects are mediated via MR, with implication of the involvement of other membrane-bound receptors such as GPER. This review will describe the ligands, receptors and intracellular mechanisms available for mineralocorticoid hormone and receptor signalling and illustrate their complex interactions in physiology and disease.
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Affiliation(s)
- Gregory S Y Ong
- Cardiovascular Endocrinology LaboratoryCentre for Endocrinology and Metabolism, Hudson Institute of Medical Research, Clayton, Victoria, Australia
- Department of MedicineSchool of Clinical Sciences, Monash University, Clayton, Victoria, Australia
| | - Morag J Young
- Cardiovascular Endocrinology LaboratoryCentre for Endocrinology and Metabolism, Hudson Institute of Medical Research, Clayton, Victoria, Australia
- Department of PhysiologySchool of Biomedical Sciences, Monash University, Clayton, Victoria, Australia
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24
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Abstract
Fibroblast growth factor-23 (FGF23) is a bone-derived hormone known to suppress phosphate reabsorption and vitamin D hormone production in the kidney. Klotho was originally discovered as an anti-aging factor, but the functional role of Klotho is still a controversial issue. Three major functions have been proposed, a hormonal function of soluble Klotho, an enzymatic function as glycosidase, and the function as an obligatory co-receptor for FGF23 signaling. The purpose of this review is to highlight the recent advances in the area of FGF23 and Klotho signaling in the kidney, in the parathyroid gland, in the cardiovascular system, in bone, and in the central nervous system. During recent years, major new functions of FGF23 and Klotho have been discovered in these organ systems. Based on these novel findings, FGF23 has emerged as a pleiotropic endocrine and auto-/paracrine factor influencing not only mineral metabolism but also cardiovascular function.
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25
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Lou Y, Zhang F, Luo Y, Wang L, Huang S, Jin F. Serum and Glucocorticoid Regulated Kinase 1 in Sodium Homeostasis. Int J Mol Sci 2016; 17:ijms17081307. [PMID: 27517916 PMCID: PMC5000704 DOI: 10.3390/ijms17081307] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 08/02/2016] [Accepted: 08/03/2016] [Indexed: 12/13/2022] Open
Abstract
The ubiquitously expressed serum and glucocorticoid regulated kinase 1 (SGK1) is tightly regulated by osmotic and hormonal signals, including glucocorticoids and mineralocorticoids. Recently, SGK1 has been implicated as a signal hub for the regulation of sodium transport. SGK1 modulates the activities of multiple ion channels and carriers, such as epithelial sodium channel (ENaC), voltage-gated sodium channel (Nav1.5), sodium hydrogen exchangers 1 and 3 (NHE1 and NHE3), sodium-chloride symporter (NCC), and sodium-potassium-chloride cotransporter 2 (NKCC2); as well as the sodium-potassium adenosine triphosphatase (Na+/K+-ATPase) and type A natriuretic peptide receptor (NPR-A). Accordingly, SGK1 is implicated in the physiology and pathophysiology of Na+ homeostasis. Here, we focus particularly on recent findings of SGK1’s involvement in Na+ transport in renal sodium reabsorption, hormone-stimulated salt appetite and fluid balance and discuss the abnormal SGK1-mediated Na+ reabsorption in hypertension, heart disease, edema with diabetes, and embryo implantation failure.
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Affiliation(s)
- Yiyun Lou
- Department of Reproductive Endocrinology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, Zhejiang, China.
- Department of Gynaecology, Hangzhou Hospital of Traditional Chinese Medicine, Hangzhou 310007, Zhejiang, China.
| | - Fan Zhang
- Department of Reproductive Endocrinology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, Zhejiang, China.
| | - Yuqin Luo
- Department of Reproductive Endocrinology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, Zhejiang, China.
| | - Liya Wang
- Department of Reproductive Endocrinology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, Zhejiang, China.
| | - Shisi Huang
- Department of Reproductive Endocrinology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, Zhejiang, China.
| | - Fan Jin
- Department of Reproductive Endocrinology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, Zhejiang, China.
- Key Laboratory of Reproductive Genetics, National Ministry of Education (Zhejiang University), Women's Reproductive Healthy Laboratory of Zhejiang Province, Hangzhou 310058, Zhejiang, China.
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26
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Xu C, Lu A, Wang H, Fang H, Zhou L, Sun P, Yang T. (Pro)Renin receptor regulates potassium homeostasis through a local mechanism. Am J Physiol Renal Physiol 2016; 313:F641-F656. [PMID: 27440776 DOI: 10.1152/ajprenal.00043.2016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 07/12/2016] [Accepted: 07/18/2016] [Indexed: 11/22/2022] Open
Abstract
(Pro)renin receptor (PRR) is highly expressed in the distal nephron, but it has an unclear functional implication. The present study was conducted to explore a potential role of renal PRR during high K+ (HK) loading. In normal Sprague-Dawley rats, a 1-wk HK intake increased renal expression of full-length PRR and urinary excretion of soluble PRR (sPRR). Administration of PRO20, a decoy peptide antagonist of PRR, in K+-loaded animals elevated plasma K+ level and decreased urinary K+ excretion, accompanied with suppressed urinary aldosterone excretion and intrarenal aldosterone levels. HK downregulated Na+-Cl- cotransporter (NCC) expression but upregulated CYP11B2 (cytochrome P-450, family 11, subfamily B, polypeptide 2), renal outer medullary K+ channel (ROMK), calcium-activated potassium channel subunit α1 (α-BK), α-Na+-K+-ATPase (α-NKA), and epithelial Na+ channel subunit β (β-ENaC), all of which were blunted by PRO20. After HK loading was completed, urinary, but not plasma renin, was upregulated, which was blunted by PRO20. The same experiments that were performed using adrenalectomized (ADX) rats yielded similar results. Interestingly, spironolactone treatment in HK-loaded ADX rats attenuated kaliuresis but promoted natriuresis, which was associated with the suppressed responses of β-ENaC, α-NKA, ROMK, and α-BK protein expression. Taken together, we discovered a novel role of renal PRR in regulation of K+ homeostasis through a local mechanism involving intrarenal renin-angiotensin-aldosterone system and coordinated regulation of membrane Na+- and K+-transporting proteins.
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Affiliation(s)
- Chuanming Xu
- Institute of Hypertension, Sun Yat-sen University School of Medicine, Guangzhou, China
| | - Aihua Lu
- Institute of Hypertension, Sun Yat-sen University School of Medicine, Guangzhou, China
| | - Hong Wang
- Institute of Hypertension, Sun Yat-sen University School of Medicine, Guangzhou, China
| | - Hui Fang
- Institute of Hypertension, Sun Yat-sen University School of Medicine, Guangzhou, China
| | - Li Zhou
- Institute of Hypertension, Sun Yat-sen University School of Medicine, Guangzhou, China
| | - Peng Sun
- Anesthesiology, Sun Yat-sen University Cancer Center, Guangzhou, China; and
| | - Tianxin Yang
- Institute of Hypertension, Sun Yat-sen University School of Medicine, Guangzhou, China; .,Internal Medicine, University of Utah and Veterans Affairs Medical Center, Salt Lake City, Utah
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27
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The sodium chloride cotransporter (NCC) and epithelial sodium channel (ENaC) associate. Biochem J 2016; 473:3237-52. [PMID: 27422782 DOI: 10.1042/bcj20160312] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 07/11/2016] [Indexed: 11/17/2022]
Abstract
The thiazide-sensitive sodium chloride cotransporter (NCC) and the epithelial sodium channel (ENaC) are two of the most important determinants of salt balance and thus systemic blood pressure. Abnormalities in either result in profound changes in blood pressure. There is one segment of the nephron where these two sodium transporters are coexpressed, the second part of the distal convoluted tubule. This is a key part of the aldosterone-sensitive distal nephron, the final regulator of salt handling in the kidney. Aldosterone is the key hormonal regulator for both of these proteins. Despite these shared regulators and coexpression in a key nephron segment, associations between these proteins have not been investigated. After confirming apical localization of these proteins, we demonstrated the presence of functional transport proteins and native association by blue native PAGE. Extensive coimmunoprecipitation experiments demonstrated a consistent interaction of NCC with α- and γ-ENaC. Mammalian two-hybrid studies demonstrated direct binding of NCC to ENaC subunits. Fluorescence resonance energy transfer and immunogold EM studies confirmed that these transport proteins are within appropriate proximity for direct binding. Additionally, we demonstrate that there are functional consequences of this interaction, with inhibition of NCC affecting the function of ENaC. This novel finding of an association between ENaC and NCC could alter our understanding of salt transport in the distal tubule.
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28
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Dbouk HA, Huang CL, Cobb MH. Hypertension: the missing WNKs. Am J Physiol Renal Physiol 2016; 311:F16-27. [PMID: 27009339 PMCID: PMC4967160 DOI: 10.1152/ajprenal.00358.2015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 03/16/2016] [Indexed: 12/23/2022] Open
Abstract
The With no Lysine [K] (WNK) family of enzymes are central in the regulation of blood pressure. WNKs have been implicated in hereditary hypertension disorders, mainly through control of the activity and levels of ion cotransporters and channels. Actions of WNKs in the kidney have been heavily investigated, and recent studies have provided insight into not only the regulation of these enzymes but also how mutations in WNKs and their interacting partners contribute to hypertensive disorders. Defining the roles of WNKs in the cardiovascular system will provide clues about additional mechanisms by which WNKs can regulate blood pressure. This review summarizes recent developments in the regulation of the WNK signaling cascade and its role in regulation of blood pressure.
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Affiliation(s)
- Hashem A Dbouk
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas; and
| | - Chou-Long Huang
- Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Melanie H Cobb
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas; and
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29
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Abstract
PURPOSE OF REVIEW Fibroblast growth factor-23 (FGF23) is a bone-derived hormone known to suppress phosphate reabsorption in the kidney. The purpose of this review was to highlight the recent advances in the area of FGF23-regulated solute transport in the kidney. RECENT FINDINGS Recent evidence suggests that FGF23 suppresses phosphate reabsorption in renal proximal tubular epithelium by a Klotho-dependent, FGF receptor (FGFR)-1 and FGFR4-mediated signaling mechanism that may also involve Janus kinase 3. Moreover, it was recently established that FGF23 signaling in the distal renal tubule targets with-no-lysine kinase-4 (WNK4), a key molecule in the regulation of solute transport in the distal nephron. By targeting WNK4, FGF23 has been shown to increase the membrane abundance of the epithelial calcium channel TRPV5 and of the sodium-chloride cotransporter NCC, resulting in augmented renal calcium and sodium reabsorption. SUMMARY Significant progress has been made in the further characterization of the signaling pathways involved in the FGF23-induced inhibition of phosphate transport in proximal tubular epithelium, and major new functions of FGF23 in solute transport have been discovered in distal renal tubules. The calcium- and sodium-conserving functions of FGF23 may have major implications for the pathophysiology of cardiovascular diseases. VIDEO ABSTRACT.
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30
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Czogalla J, Vohra T, Penton D, Kirschmann M, Craigie E, Loffing J. The mineralocorticoid receptor (MR) regulates ENaC but not NCC in mice with random MR deletion. Pflugers Arch 2016; 468:849-58. [PMID: 26898302 DOI: 10.1007/s00424-016-1798-5] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Revised: 02/03/2016] [Accepted: 02/08/2016] [Indexed: 12/13/2022]
Abstract
Aldosterone binds to the mineralocorticoid receptor (MR) and increases renal Na(+) reabsorption via up-regulation of the epithelial Na(+) channel (ENaC) and the Na(+)-K(+)-ATPase in the collecting system (CS) and possibly also via the NaCl cotransporter (NCC) in the distal convoluted tubule (DCT). However, whether aldosterone directly regulates NCC via MR or indirectly through systemic alterations remains controversial. We used mice with deletion of MR in ∼20 % of renal tubule cells (MR/X mice), in which MR-positive (MR(wt)) and -negative (MR(ko)) cells can be studied side-by-side in the same physiological context. Adult MR/X mice showed similar mRNA and protein levels of renal ion transport proteins to control mice. In MR/X mice, no differences in NCC abundance and phosphorylation was seen between MR(wt) and MR(ko) cells and dietary Na(+) restriction up-regulated NCC to similar extent in both groups of cells. In contrast, MR(ko) cells in the CS did not show any detectable alpha-ENaC abundance or apical targeting of ENaC neither on control diet nor in response to dietary Na(+) restriction. Furthermore, Na(+)-K(+)-ATPase expression was unaffected in MR(ko) cells of the DCT, while it was lost in MR(ko) cells of the CS. In conclusion, MR is crucial for ENaC and Na(+)-K(+)-ATPase regulation in the CS, but is dispensable for NCC and Na(+)-K(+)-ATPase regulation in the DCT.
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Affiliation(s)
- Jan Czogalla
- Institute of Anatomy, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland.,Swiss National Centre for Competence in Research "Kidney Control of Homeostasis", Zurich, Switzerland
| | - Twinkle Vohra
- Institute of Anatomy, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
| | - David Penton
- Institute of Anatomy, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland.,Swiss National Centre for Competence in Research "Kidney Control of Homeostasis", Zurich, Switzerland
| | - Moritz Kirschmann
- Center for Microscopy and Image Analysis, University of Zurich, Zurich, Switzerland
| | - Eilidh Craigie
- Institute of Anatomy, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland.,Swiss National Centre for Competence in Research "Kidney Control of Homeostasis", Zurich, Switzerland
| | - Johannes Loffing
- Institute of Anatomy, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland. .,Swiss National Centre for Competence in Research "Kidney Control of Homeostasis", Zurich, Switzerland.
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31
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Abstract
The impaired capacity of the kidney to excrete sodium plays an essential role in the development of hypertension. Adrenal corticosteroids control renal handling of sodium by regulating tubular sodium reabsorption in the distal nephron where both mineralocorticoid receptors (MR) and glucocorticoid receptors are expressed. In addition, cell type- and segment-specific expression of 11β-HSD2 and sodium transporters such as Na-Cl cotransporter (NCC), epithelial sodium channel (ENaC), and pendrin/Na(+)-driven Cl(-)/HCO3 (-) exchanger (NDCBE) builds a distinctive model of sodium transport in the aldosterone-sensitive distal nephron. Aberrant MR activation in the distal nephron triggers salt-sensitive hypertension and hypokalemia through inappropriate sodium reabsorption and potassium secretion. However, MR activity is not necessarily modulated by the ligand alone. Recently, several lines of evidence revealed alternative mechanisms that regulate the activity of MR in a ligand-independent manner or through ligand binding modulation. This review summarizes the disorders related to MR activation in individual tubular cells and highlights the renal mechanism of salt-sensitive hypertension and new approaches for the prevention and treatment of this disease.
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Affiliation(s)
- Nobuhiro Ayuzawa
- Department of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8904, Japan
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32
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Rojas-Vega L, Gamba G. Mini-review: regulation of the renal NaCl cotransporter by hormones. Am J Physiol Renal Physiol 2016; 310:F10-4. [DOI: 10.1152/ajprenal.00354.2015] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The renal thiazide-sensitive NaCl cotransporter, NCC, is the major pathway for salt reabsorption in the distal convoluted tubule. The activity of this cotransporter is critical for regulation of several physiological variables such as blood pressure, serum potassium, acid base metabolism, and urinary calcium excretion. Therefore, it is not surprising that numerous hormone-signaling pathways regulate NCC activity to maintain homeostasis. In this review, we will provide an overview of the most recent evidence on NCC modulation by aldosterone, angiotensin II, vasopressin, glucocorticoids, insulin, norepinephrine, estradiol, progesterone, prolactin, and parathyroid hormone.
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Affiliation(s)
- Lorena Rojas-Vega
- Molecular Physiology Unit, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico; and
- Department of Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - Gerardo Gamba
- Molecular Physiology Unit, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico; and
- Department of Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
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33
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Terker AS, Yarbrough B, Ferdaus MZ, Lazelle RA, Erspamer KJ, Meermeier NP, Park HJ, McCormick JA, Yang CL, Ellison DH. Direct and Indirect Mineralocorticoid Effects Determine Distal Salt Transport. J Am Soc Nephrol 2015; 27:2436-45. [PMID: 26712527 DOI: 10.1681/asn.2015070815] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 11/17/2015] [Indexed: 11/03/2022] Open
Abstract
Excess aldosterone is an important contributor to hypertension and cardiovascular disease. Conversely, low circulating aldosterone causes salt wasting and hypotension. Aldosterone activates mineralocorticoid receptors (MRs) to increase epithelial sodium channel (ENaC) activity. However, aldosterone may also stimulate the thiazide-sensitive Na(+)-Cl(-) cotransporter (NCC). Here, we generated mice in which MRs could be deleted along the nephron to test this hypothesis. These kidney-specific MR-knockout mice exhibited salt wasting, low BP, and hyperkalemia. Notably, we found evidence of deficient apical orientation and cleavage of ENaC, despite the salt wasting. Although these mice also exhibited deficient NCC activity, NCC could be stimulated by restricting dietary potassium, which also returned BP to control levels. Together, these results indicate that MRs regulate ENaC directly, but modulation of NCC is mediated by secondary changes in plasma potassium concentration. Electrolyte balance and BP seem to be determined, therefore, by a delicate interplay between direct and indirect mineralocorticoid actions in the distal nephron.
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Affiliation(s)
- Andrew S Terker
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon; and
| | - Bethzaida Yarbrough
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon; and
| | - Mohammed Z Ferdaus
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon; and
| | - Rebecca A Lazelle
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon; and
| | - Kayla J Erspamer
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon; and
| | - Nicholas P Meermeier
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon; and
| | - Hae J Park
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon; and
| | - James A McCormick
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon; and
| | - Chao-Ling Yang
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon; and Renal Section, Veterans Affairs Portland Health Care System, Portland, Oregon
| | - David H Ellison
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon; and Renal Section, Veterans Affairs Portland Health Care System, Portland, Oregon
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34
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Roy A, Al-Qusairi L, Donnelly BF, Ronzaud C, Marciszyn AL, Gong F, Chang YPC, Butterworth MB, Pastor-Soler NM, Hallows KR, Staub O, Subramanya AR. Alternatively spliced proline-rich cassettes link WNK1 to aldosterone action. J Clin Invest 2015; 125:3433-48. [PMID: 26241057 DOI: 10.1172/jci75245] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 06/11/2015] [Indexed: 11/17/2022] Open
Abstract
The thiazide-sensitive NaCl cotransporter (NCC) is important for renal salt handling and blood-pressure homeostasis. The canonical NCC-activating pathway consists of With-No-Lysine (WNK) kinases and their downstream effector kinases SPAK and OSR1, which phosphorylate NCC directly. The upstream mechanisms that connect physiological stimuli to this system remain obscure. Here, we have shown that aldosterone activates SPAK/OSR1 via WNK1. We identified 2 alternatively spliced exons embedded within a proline-rich region of WNK1 that contain PY motifs, which bind the E3 ubiquitin ligase NEDD4-2. PY motif-containing WNK1 isoforms were expressed in human kidney, and these isoforms were efficiently degraded by the ubiquitin proteasome system, an effect reversed by the aldosterone-induced kinase SGK1. In gene-edited cells, WNK1 deficiency negated regulatory effects of NEDD4-2 and SGK1 on NCC, suggesting that WNK1 mediates aldosterone-dependent activity of the WNK/SPAK/OSR1 pathway. Aldosterone infusion increased proline-rich WNK1 isoform abundance in WT mice but did not alter WNK1 abundance in hypertensive Nedd4-2 KO mice, which exhibit high baseline WNK1 and SPAK/OSR1 activity toward NCC. Conversely, hypotensive Sgk1 KO mice exhibited low WNK1 expression and activity. Together, our findings indicate that the proline-rich exons are modular cassettes that convert WNK1 into a NEDD4-2 substrate, thereby linking aldosterone and other NEDD4-2-suppressing antinatriuretic hormones to NCC phosphorylation status.
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35
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West CA, McDonough AA, Masilamani SME, Verlander JW, Baylis C. Renal NCC is unchanged in the midpregnant rat and decreased in the late pregnant rat despite avid renal Na+ retention. Am J Physiol Renal Physiol 2015; 309:F63-70. [PMID: 25925254 DOI: 10.1152/ajprenal.00147.2015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Accepted: 04/22/2015] [Indexed: 11/22/2022] Open
Abstract
Pregnancy is characterized by plasma volume expansion due to Na(+) retention, driven by aldosterone. The aldosterone-responsive epithelial Na(+) channel is activated in the kidney in pregnancy. In the present study, we investigated the aldosterone-responsive Na(+)-Cl(-) cotransporter (NCC) in mid- and late pregnant rats compared with virgin rats. We determined the abundance of total NCC, phosphorylated NCC (pNCC; pT53, pS71 and pS89), phosphorylated STE20/SPS-1-related proline-alanine-rich protein kinase (pSPAK; pS373), and phosphorylated oxidative stress-related kinase (pOSR1; pS325) in the kidney cortex. We also measured mRNA expression of NCC and members of the SPAK/NCC regulatory kinase network, serum and glucocorticoid-regulated kinase (SGK)1, total with no lysine kinase (WNK)1, WNK3, and WNK4. Additionally, we performed immunohistochemistry for NCC kidneys from virgin and pregnant rats. Total NCC, pNCC, and pSPAK/OSR1 abundance were unchanged in midpregnant versus virgin rats. In late pregnant versus virgin rats, total NCC and pNCC were decreased; however, pSPAK/OSR1 was unchanged. We detected no differences in mRNA expression of NCC, SGK1, total WNK1, WNK3, and WNK4. By immunohistochemistry, NCC was mainly localized to the apical region in virgin rats, and density in the apical region was reduced in late pregnancy. Therefore, despite high circulating aldosterone levels in pregnancy, the aldosterone-responsive transporter NCC is not increased in total or activated (phosphorylated) abundance or in apical localization in midpregnant rats, and all are reduced in late pregnancy. This contrasts to the mineralocorticoid-mediated activation of the epithelial Na(+) channel, which we have previously reported. Why and how NCC escapes aldosterone activation in pregnancy is not clear but may relate to regional differences in aldosterone sensitivity the increased K(+) intake or other undefined mechanisms.
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Affiliation(s)
- Crystal A West
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida;
| | - Alicia A McDonough
- Department of Cell and Neurobiology, Keck School of Medicine of University of Southern California, Los Angeles, California; and
| | - Shyama M E Masilamani
- Department of Internal Medicine, Virginia Commonwealth University Medical Center, Richmond, Virginia
| | - Jill W Verlander
- Department of Medicine, University of Florida, Gainesville, Florida
| | - Chris Baylis
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida; Department of Medicine, University of Florida, Gainesville, Florida
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36
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Nishimoto M, Fujita T. Renal mechanisms of salt-sensitive hypertension: contribution of two steroid receptor-associated pathways. Am J Physiol Renal Physiol 2015; 308:F377-87. [DOI: 10.1152/ajprenal.00477.2013] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Although salt is a major environmental factor in the development of hypertension, the degree of salt sensitivity varies widely among individuals. The mechanisms responsible for this variation remain to be elucidated. Recent studies have revealed the involvement of two important signaling pathways in renal tubules that play key roles in electrolyte balance and the maintenance of normal blood pressure: the β2-adrenergic stimulant-glucocorticoid receptor (GR)-with-no-lysine kinase (WNK)4-Na+-Cl− cotransporter pathway, which is active in distal convoluted tubule (DCT)1, and the Ras-related C3 botulinum toxin substrate (Rac)1-mineralocorticoid receptor (MR) pathway, which is active in DCT2, connecting tubules, and collecting ducts. β2-Adrenergic stimulation due to increased renal sympathetic activity in obesity- and salt-induced hypertension suppresses histone deacetylase 8 activity via cAMP/PKA signaling, increasing the accessibility of GRs to the negative GR response element in the WNK4 promoter. This results in the suppression of WNK4 transcription followed by the activation of Na+-Cl− cotransporters in the DCT and elevated Na+ retention and blood pressure upon salt loading. Rac1 activates MRs, even in the absence of ligand binding, with this activity increased in the presence of ligand. In salt-sensitive animals, Rac1 activation due to salt loading activates MRs in DCT2, connecting tubules, and collecting ducts. Thus, GRs and MRs are independently involved in two pathways responsible for renal Na+ handling and salt-sensitive hypertension. These findings suggest novel therapeutic targets and may lead to the development of diagnostic tools to determine salt sensitivity in hypertensive patients.
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Affiliation(s)
- Mitsuhiro Nishimoto
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Toshiro Fujita
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
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Ko B, Mistry A, Hanson L, Mallick R, Hoover RS. Mechanisms of angiotensin II stimulation of NCC are time-dependent in mDCT15 cells. Am J Physiol Renal Physiol 2015; 308:F720-7. [PMID: 25651566 DOI: 10.1152/ajprenal.00465.2014] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Accepted: 01/26/2015] [Indexed: 12/17/2022] Open
Abstract
Angiotensin II (ANG II) increases thiazide-sensitive sodium-chloride cotransporter (NCC) activity both acutely and chronically. ANG II has been implicated as a switch that turns WNK4 from an inhibitor of NCC into an activator of NCC, and ANG II's effect on NCC appears to require WNK4. Chronically, ANG II stimulation of NCC results in an increase in total and phosphorylated NCC, but the role of NCC phosphorylation in acute ANG II actions is unclear. Here, using a mammalian cell model with robust native NCC activity, we corroborate the role that ANG II plays in WNK4 regulation and clarify the role of Ste20-related proline alanine-rich kinase (SPAK)-induced NCC phosphorylation in ANG II action. ANG II was noted to have a biphasic effect on NCC, with a peak increase in NCC activity in the physiologic range of 10(-11) M ANG II. This effect was apparent as early as 15 min and remained sustained through 120 min. These changes correlated with significant increases in NCC surface protein expression. Knockdown of WNK4 expression sharply attenuated the effect of ANG II. SPAK knockdown did not affect ANG II action at early time points (15 and 30 min), but it did attenuate the response at 60 min. Correspondingly, NCC phosphorylation did not increase at 15 or 30 min, but increased significantly at 60 min. We therefore conclude that within minutes of an increase in ANG II, NCC is rapidly trafficked to the cell surface in a phosphorylation-independent but WNK4-dependent manner. Then, after 60 min, ANG II induces SPAK-dependent phosphorylation of NCC.
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Affiliation(s)
- Benjamin Ko
- Department of Medicine, University of Chicago, Chicago, Illinois;
| | - Abinash Mistry
- Division of Nephrology, Department of Medicine, Emory University, Atlanta, Georgia; and
| | - Lauren Hanson
- Department of Medicine, University of Chicago, Chicago, Illinois
| | - Rickta Mallick
- Division of Nephrology, Department of Medicine, Emory University, Atlanta, Georgia; and
| | - Robert S Hoover
- Division of Nephrology, Department of Medicine, Emory University, Atlanta, Georgia; and Atlanta Veteran's Administration Medical Center, Decatur, Georgia
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Andrukhova O, Slavic S, Smorodchenko A, Zeitz U, Shalhoub V, Lanske B, Pohl EE, Erben RG. FGF23 regulates renal sodium handling and blood pressure. EMBO Mol Med 2014; 6:744-59. [PMID: 24797667 PMCID: PMC4203353 DOI: 10.1002/emmm.201303716] [Citation(s) in RCA: 239] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Fibroblast growth factor-23 (FGF23) is a bone-derived hormone regulating renal phosphate reabsorption and vitamin D synthesis in renal proximal tubules. Here, we show that FGF23 directly regulates the membrane abundance of the Na(+):Cl(-) co-transporter NCC in distal renal tubules by a signaling mechanism involving the FGF receptor/αKlotho complex, extracellular signal-regulated kinase 1/2 (ERK1/2), serum/glucocorticoid-regulated kinase 1 (SGK1), and with-no lysine kinase-4 (WNK4). Renal sodium (Na(+)) reabsorption and distal tubular membrane expression of NCC are reduced in mouse models of Fgf23 and αKlotho deficiency. Conversely, gain of FGF23 function by injection of wild-type mice with recombinant FGF23 or by elevated circulating levels of endogenous Fgf23 in Hyp mice increases distal tubular Na(+) uptake and membrane abundance of NCC, leading to volume expansion, hypertension, and heart hypertrophy in a αKlotho and dietary Na(+)-dependent fashion. The NCC inhibitor chlorothiazide abrogates FGF23-induced volume expansion and heart hypertrophy. Our findings suggest that FGF23 is a key regulator of renal Na(+) reabsorption and plasma volume, and may explain the association of FGF23 with cardiovascular risk in chronic kidney disease patients.
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Affiliation(s)
| | | | | | - Ute Zeitz
- University of Veterinary Medicine Vienna, Vienna, Austria
| | | | - Beate Lanske
- Harvard School of Dental Medicine, Boston, MA, USA
| | - Elena E Pohl
- University of Veterinary Medicine Vienna, Vienna, Austria
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Richards J, Ko B, All S, Cheng KY, Hoover RS, Gumz ML. A role for the circadian clock protein Per1 in the regulation of the NaCl co-transporter (NCC) and the with-no-lysine kinase (WNK) cascade in mouse distal convoluted tubule cells. J Biol Chem 2014; 289:11791-11806. [PMID: 24610784 DOI: 10.1074/jbc.m113.531095] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
It has been well established that blood pressure and renal function undergo circadian fluctuations. We have demonstrated that the circadian protein Per1 regulates multiple genes involved in sodium transport in the collecting duct of the kidney. However, the role of Per1 in other parts of the nephron has not been investigated. The distal convoluted tubule (DCT) plays a critical role in renal sodium reabsorption. Sodium is reabsorbed in this segment through the actions of the NaCl co-transporter (NCC), which is regulated by the with-no-lysine kinases (WNKs). The goal of this study was to test if Per1 regulates sodium transport in the DCT through modulation of NCC and the WNK kinases, WNK1 and WNK4. Pharmacological blockade of nuclear Per1 entry resulted in decreased mRNA expression of NCC and WNK1 but increased expression of WNK4 in the renal cortex of mice. These findings were confirmed by using Per1 siRNA and pharmacological blockade of Per1 nuclear entry in mDCT15 cells, a model of the mouse distal convoluted tubule. Transcriptional regulation was demonstrated by changes in short lived heterogeneous nuclear RNA. Chromatin immunoprecipitation experiments demonstrated interaction of Per1 and CLOCK with the promoters of NCC, WNK1, and WNK4. This interaction was modulated by blockade of Per1 nuclear entry. Importantly, NCC protein expression and NCC activity, as measured by thiazide-sensitive, chloride-dependent (22)Na uptake, were decreased upon pharmacological inhibition of Per1 nuclear entry. Taken together, these data demonstrate a role for Per1 in the transcriptional regulation of NCC, WNK1, and WNK4.
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Affiliation(s)
- Jacob Richards
- Departments of Medicine, University of Florida, Gainesville, Florida 32610; Departments of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida 32610
| | - Benjamin Ko
- Department of Medicine, University of Chicago, Chicago, Illinois 60637
| | - Sean All
- Departments of Medicine, University of Florida, Gainesville, Florida 32610
| | - Kit-Yan Cheng
- Departments of Medicine, University of Florida, Gainesville, Florida 32610
| | - Robert S Hoover
- Division of Nephrology, Department of Medicine, Emory University, Atlanta, Georgia 30322; Research Service, Atlanta Veterans Affairs Medical Center, Atlanta, Georgia 30033
| | - Michelle L Gumz
- Departments of Medicine, University of Florida, Gainesville, Florida 32610; Departments of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida 32610.
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Fujita T. Mechanism of salt-sensitive hypertension: focus on adrenal and sympathetic nervous systems. J Am Soc Nephrol 2014; 25:1148-55. [PMID: 24578129 DOI: 10.1681/asn.2013121258] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
A central role for the kidney among the systems contributing to BP regulation and the development of hypertension has been proposed. Both the aldosterone/mineralocorticoid receptor pathway and the renal sympathetic nervous system have important roles in the regulation of renal excretory function and BP control, but the mechanisms underlying these processes have remained unclear. However, recent studies revealed the activation of two pathways in salt-sensitive hypertension. Notably, Rac1, a member of the Rho-family of small GTP binding proteins, was identified as a novel ligand-independent modulator of mineralocorticoid receptor activity. Furthermore, these studies point to crucial roles for the Rac1-mineralocorticoid receptor-NCC/ENaC and the renal β-adrenergic stimulant-glucocorticoid receptor-WNK4-NCC pathways in certain rodent models of salt-sensitive hypertension. The nuclear mineralocorticoid and glucocorticoid receptors may contribute to impaired renal excretory function and the resulting salt-sensitive hypertension by increasing sodium reabsorption at different tubular segments. This review provides an in-depth discussion of the evidence supporting these conclusions and considers the significance with regard to treating salt-sensitive hypertension and salt-induced cardiorenal injury.
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Affiliation(s)
- Toshiro Fujita
- Department of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan; and CREST, Tokyo, Japan
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Moes AD, van der Lubbe N, Zietse R, Loffing J, Hoorn EJ. The sodium chloride cotransporter SLC12A3: new roles in sodium, potassium, and blood pressure regulation. Pflugers Arch 2013; 466:107-18. [PMID: 24310820 DOI: 10.1007/s00424-013-1407-9] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Revised: 11/19/2013] [Accepted: 11/20/2013] [Indexed: 12/14/2022]
Abstract
SLC12A3 encodes the thiazide-sensitive sodium chloride cotransporter (NCC), which is primarily expressed in the kidney, but also in intestine and bone. In the kidney, NCC is located in the apical plasma membrane of epithelial cells in the distal convoluted tubule. Although NCC reabsorbs only 5 to 10% of filtered sodium, it is important for the fine-tuning of renal sodium excretion in response to various hormonal and non-hormonal stimuli. Several new roles for NCC in the regulation of sodium, potassium, and blood pressure have been unraveled recently. For example, the recent discoveries that NCC is activated by angiotensin II but inhibited by dietary potassium shed light on how the kidney handles sodium during hypovolemia (high angiotensin II) and hyperkalemia. The additive effect of angiotensin II and aldosterone maximizes sodium reabsorption during hypovolemia, whereas the inhibitory effect of potassium on NCC increases delivery of sodium to the potassium-secreting portion of the nephron. In addition, great steps have been made in unraveling the molecular machinery that controls NCC. This complex network consists of kinases and ubiquitinases, including WNKs, SGK1, SPAK, Nedd4-2, Cullin-3, and Kelch-like 3. The pathophysiological significance of this network is illustrated by the fact that modification of each individual protein in the network changes NCC activity and results in salt-dependent hypotension or hypertension. This review aims to summarize these new insights in an integrated manner while identifying unanswered questions.
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Affiliation(s)
- Arthur D Moes
- Department of Internal Medicine, Erasmus Medical Center, PO Box 2040, Room H-438, 3000 CA, Rotterdam, The Netherlands
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