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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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Duan XP, Zhang CB, Wang WH, Lin DH. Role of calcineurin in regulating renal potassium (K +) excretion: Mechanisms of calcineurin inhibitor-induced hyperkalemia. Acta Physiol (Oxf) 2024:e14189. [PMID: 38860527 DOI: 10.1111/apha.14189] [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: 03/21/2024] [Revised: 05/28/2024] [Accepted: 05/30/2024] [Indexed: 06/12/2024]
Abstract
Calcineurin, protein phosphatase 2B (PP2B) or protein phosphatase 3 (PP3), is a calcium-dependent serine/threonine protein phosphatase. Calcineurin is widely expressed in the kidney and regulates renal Na+ and K+ transport. In the thick ascending limb, calcineurin plays a role in inhibiting NKCC2 function by promoting the dephosphorylation of the cotransporter and an intracellular sorting receptor, called sorting-related-receptor-with-A-type repeats (SORLA), is involved in modulating the effect of calcineurin on NKCC2. Calcineurin also participates in regulating thiazide-sensitive NaCl-cotransporter (NCC) in the distal convoluted tubule. The mechanisms by which calcineurin regulates NCC include directly dephosphorylation of NCC, regulating Kelch-like-3/CUL3 E3 ubiquitin-ligase complex, which is responsible for WNK (with-no-lysin-kinases) ubiquitination, and inhibiting Kir4.1/Kir5.1, which determines NCC expression/activity. Finally, calcineurin is also involved in regulating ROMK (Kir1.1) channels in the cortical collecting duct and Cyp11 2 expression in adrenal zona glomerulosa. In summary, calcineurin is involved in the regulation of NKCC2, NCC, and inwardly rectifying K+ channels in the kidney, and it also plays a role in modulating aldosterone synthesis in adrenal gland, which regulates epithelial-Na+-channel expression/activity. Thus, application of calcineurin inhibitors (CNIs) is expected to abrupt calcineurin-mediated regulation of transepithelial Na+ and K+ transport in the kidney. Consequently, CNIs cause hypertension, compromise renal K+ excretion, and induce hyperkalemia.
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Affiliation(s)
- Xin-Peng Duan
- Department of Physiology, Xuzhou Medical University, Xuzhou, China
| | - Cheng-Biao Zhang
- Department of Physiology, Xuzhou Medical University, Xuzhou, China
- Department of Pharmacology, New York Medical College, Valhalla, New York, USA
| | - Wen-Hui Wang
- Department of Pharmacology, New York Medical College, Valhalla, New York, USA
| | - Dao-Hong Lin
- Department of Pharmacology, New York Medical College, Valhalla, New York, USA
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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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Ferdaus MZ, Koumangoye RB, Welling PA, Delpire E. Kinase Scaffold Cab39 Is Necessary for Phospho-Activation of the Thiazide-Sensitive NCC. Hypertension 2024; 81:801-810. [PMID: 38258567 PMCID: PMC10954405 DOI: 10.1161/hypertensionaha.123.22464] [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: 11/26/2023] [Accepted: 01/11/2024] [Indexed: 01/24/2024]
Abstract
BACKGROUND Potassium regulates the WNK (with no lysine kinase)-SPAK (STE20/SPS1-related proline/alanine-rich kinase) signaling axis, which in turn controls the phosphorylation and activation of the distal convoluted tubule thiazide-sensitive NCC (sodium-chloride cotransporter) for sodium-potassium balance. Although their roles in the kidney have not been investigated, it has been postulated that Cab39 (calcium-binding protein 39) or Cab39l (Cab39-like) is required for SPAK/OSR1 (oxidative stress response 1) activation. This study demonstrates how they control the WNK-SPAK/OSR1-NCC pathway. METHODS We created a global knockout of Cab39l and a tamoxifen-inducible, NCC-driven, Cab39 knockout. The 2 lines were crossed to generate Cab39-DKO (Cab39 double knockout) animals. Mice were studied under control and low-potassium diet, which activates WNK-SPAK/OSR1-NCC phosphorylation. Western blots were used to assess the expression and phosphorylation of proteins. Blood and urine electrolytes were measured to test for compromised NCC function. Immunofluorescence studies were conducted to localize SPAK and OSR1. RESULTS Both Cab39l and Cab39 are expressed in distal convoluted tubule, and only the elimination of both leads to a striking absence of NCC phosphorylation. Cab39-DKO mice exhibited a loss-of-NCC function, like in Gitelman syndrome. In contrast to the apical membrane colocalization of SPAK with NCC in wild-type mice, SPAK and OSR1 become confined to intracellular puncta in the Cab39-DKO mice. CONCLUSIONS In the absence of Cab39 proteins, NCC cannot be phosphorylated, resulting in a Gitelman-like phenotype. Cab39 proteins function to localize SPAK at the apical membrane with NCC, reminiscent of the Cab39 yeast homolog function, translocating kinases during cytokinesis.
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Affiliation(s)
- Mohammed Z Ferdaus
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN (M.Z.F, R.B.K., E.D.)
| | - Rainelli B Koumangoye
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN (M.Z.F, R.B.K., E.D.)
| | - Paul A Welling
- Division of Nephrology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD (P.A.W.)
| | - Eric Delpire
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN (M.Z.F, R.B.K., E.D.)
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Duan XP, Xiao Y, Su XT, Zheng JY, Gurley S, Emathinger J, Yang CL, McCormick J, Ellison DH, Lin DH, Wang WH. Role of Angiotensin II Type 1a Receptor (AT1aR) of Renal Tubules in Regulating Inwardly Rectifying Potassium Channels 4.2 (Kir4.2), Kir4.1, and Epithelial Na + Channel (ENaC). Hypertension 2024; 81:126-137. [PMID: 37909221 PMCID: PMC10842168 DOI: 10.1161/hypertensionaha.123.21389] [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: 04/19/2023] [Accepted: 10/12/2023] [Indexed: 11/02/2023]
Abstract
BACKGROUND Kir4.2 and Kir4.1 play a role in regulating membrane transport in the proximal tubule (PT) and in the distal-convoluted-tubule (DCT), respectively. METHODS We generated kidney-tubule-specific-AT1aR-knockout (Ks-AT1aR-KO) mice to examine whether renal AT1aR regulates Kir4.2 and Kir4.1. RESULTS Ks-AT1aR-KO mice had a lower systolic blood pressure than Agtr1aflox/flox (control) mice. Ks-AT1aR-KO mice had a lower expression of NHE3 (Na+/H+-exchanger 3) and Kir4.2, a major Kir-channel in PT, than Agtr1aflox/flox mice. Whole-cell recording also demonstrated that the membrane potential in PT of Ks-AT1aR-KO mice was lesser negative than Agtr1aflox/flox mice. The expression of Kir4.1 and Kir5.1, Kir4.1/Kir5.1-mediated K+ currents of DCT and DCT membrane potential in Ks-AT1aR-KO mice, were similar to Agtr1aflox/flox mice. However, angiotensin II perfusion for 7 days hyperpolarized the membrane potential in PT and DCT of the control mice but not in Ks-AT1aR-KO mice, while angiotensin II perfusion did not change the expression of Kir4.1, Kir4.2, and Kir5.1. Deletion of AT1aR did not significantly affect the expression of αENaC (epithelial Na+ channel) and βENaC but increased cleaved γENaC expression. Patch-clamp experiments demonstrated that deletion of AT1aR increased amiloride-sensitive Na+-currents in the cortical-collecting duct but not in late-DCT. However, tertiapin-Q sensitive renal outer medullary potassium channel currents were similar in both genotypes. CONCLUSIONS AT1aR determines the baseline membrane potential of PT by controlling Kir4.2 expression/activity but AT1aR is not required for determining the baseline membrane potential of the DCT and Kir4.1/Kir5.1 activity/expression. However, AT1aR is required for angiotensin II-induced hyperpolarization of basolateral membrane of PT and DCT. Deletion of AT1aR had no effect on baseline renal outer medullary potassium channel activity but increased ENaC activity in the CCD.
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Affiliation(s)
- Xin-Peng Duan
- Department of Physiology, Xuzhou Medical University, Xuzhou, China
- Department of Pharmacology, New York Medical College, Valhalla, NY
| | - Yu Xiao
- Department of Physiology, Qiqihar Medical College, Heilongjiang, China
- Department of Pharmacology, New York Medical College, Valhalla, NY
| | - Xiao-Tong Su
- Department of Medicine, Oregon Health & Science University, Portland, Oregon
| | - Jun-Ya Zheng
- Department of Pharmacology, New York Medical College, Valhalla, NY
| | - Susan Gurley
- Department of Medicine, Oregon Health & Science University, Portland, Oregon
| | | | - Chao-Ling Yang
- Department of Medicine, Oregon Health & Science University, Portland, Oregon
| | - James McCormick
- Department of Medicine, Oregon Health & Science University, Portland, Oregon
| | - David H. Ellison
- Department of Medicine, Oregon Health & Science University, Portland, Oregon
| | - Dao-Hong Lin
- Department of Pharmacology, New York Medical College, Valhalla, NY
| | - Wen-Hui Wang
- Department of Pharmacology, New York Medical College, Valhalla, NY
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Grimm PR, Tatomir A, Rosenbaek LL, Kim BY, Li D, Delpire EJ, Fenton RA, Welling PA. Dietary potassium stimulates Ppp1Ca-Ppp1r1a dephosphorylation of kidney NaCl cotransporter and reduces blood pressure. J Clin Invest 2023; 133:e158498. [PMID: 37676724 PMCID: PMC10617769 DOI: 10.1172/jci158498] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 09/06/2023] [Indexed: 09/09/2023] Open
Abstract
Consumption of low dietary potassium, common with ultraprocessed foods, activates the thiazide-sensitive sodium chloride cotransporter (NCC) via the with no (K) lysine kinase/STE20/SPS1-related proline-alanine-rich protein kinase (WNK/SPAK) pathway to induce salt retention and elevate blood pressure (BP). However, it remains unclear how high-potassium "DASH-like" diets (dietary approaches to stop hypertension) inactivate the cotransporter and whether this decreases BP. A transcriptomics screen identified Ppp1Ca, encoding PP1A, as a potassium-upregulated gene, and its negative regulator Ppp1r1a, as a potassium-suppressed gene in the kidney. PP1A directly binds to and dephosphorylates NCC when extracellular potassium is elevated. Using mice genetically engineered to constitutively activate the NCC-regulatory kinase SPAK and thereby eliminate the effects of the WNK/SPAK kinase cascade, we confirmed that PP1A dephosphorylated NCC directly in a potassium-regulated manner. Prior adaptation to a high-potassium diet was required to maximally dephosphorylate NCC and lower BP in constitutively active SPAK mice, and this was associated with potassium-dependent suppression of Ppp1r1a and dephosphorylation of its cognate protein, inhibitory subunit 1 (I1). In conclusion, potassium-dependent activation of PP1A and inhibition of I1 drove NCC dephosphorylation, providing a mechanism to explain how high dietary K+ lowers BP. Shifting signaling of PP1A in favor of activation of WNK/SPAK may provide an improved therapeutic approach for treating salt-sensitive hypertension.
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Affiliation(s)
- P. Richard Grimm
- Department of Medicine (Nephrology), Johns Hopkins University School of Medicine Baltimore, Maryland, USA
- The LeDucq Potassium in Hypertension Research Network of Excellence is detailed in Supplemental Acknowledgments
| | - Anamaria Tatomir
- Department of Medicine (Nephrology), Johns Hopkins University School of Medicine Baltimore, Maryland, USA
| | - Lena L. Rosenbaek
- The LeDucq Potassium in Hypertension Research Network of Excellence is detailed in Supplemental Acknowledgments
- Department of Biomedicine, University of Aarhus, Aarhus, Denmark
| | - Bo Young Kim
- Department of Medicine (Nephrology), Johns Hopkins University School of Medicine Baltimore, Maryland, USA
- The LeDucq Potassium in Hypertension Research Network of Excellence is detailed in Supplemental Acknowledgments
| | - Dimin Li
- Department of Medicine (Nephrology), Johns Hopkins University School of Medicine Baltimore, Maryland, USA
| | - Eric J. Delpire
- The LeDucq Potassium in Hypertension Research Network of Excellence is detailed in Supplemental Acknowledgments
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, Tennssee, USA
| | - Robert A. Fenton
- The LeDucq Potassium in Hypertension Research Network of Excellence is detailed in Supplemental Acknowledgments
- Department of Biomedicine, University of Aarhus, Aarhus, Denmark
| | - Paul A. Welling
- Department of Medicine (Nephrology), Johns Hopkins University School of Medicine Baltimore, Maryland, USA
- The LeDucq Potassium in Hypertension Research Network of Excellence is detailed in Supplemental Acknowledgments
- Department of Physiology, Johns Hopkins University School of Medicine Baltimore, Maryland, USA
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Gamba G. Thirty years of the NaCl cotransporter: from cloning to physiology and structure. Am J Physiol Renal Physiol 2023; 325:F479-F490. [PMID: 37560773 PMCID: PMC10639029 DOI: 10.1152/ajprenal.00114.2023] [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: 05/02/2023] [Revised: 08/08/2023] [Accepted: 08/08/2023] [Indexed: 08/11/2023] Open
Abstract
The primary structure of the thiazide-sensitive NaCl cotransporter (NCC) was resolved 30 years ago by the molecular identification of the cDNA encoding this cotransporter, from the winter's flounder urinary bladder, following a functional expression strategy. This review outlines some aspects of how the knowledge about thiazide diuretics and NCC evolved, the history of the cloning process, and the expansion of the SLC12 family of electroneutral cotransporters. The diseases associated with activation or inactivation of NCC are discussed, as well as the molecular model by which the activity of NCC is regulated. The controversies in the field are discussed as well as recent publication of the three-dimensional model of NCC obtained by cryo-electron microscopy, revealing not only the amino acid residues critical for Na+ and Cl- translocation but also the residues critical for polythiazide binding to the transporter, opening the possibility for a new era in thiazide diuretic therapy.
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Affiliation(s)
- Gerardo Gamba
- Molecular Physiology Unit, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico
- Department of Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
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8
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Wouda RD, Gritter M, Karsten M, Michels EH, Nieuweboer TM, Danser AJ, de Borst MH, Hoorn EJ, Rotmans JI, Vogt L. Kaliuresis and Intracellular Uptake of Potassium with Potassium Citrate and Potassium Chloride Supplements: A Randomized Controlled Trial. Clin J Am Soc Nephrol 2023; 18:1260-1271. [PMID: 37382933 PMCID: PMC10578626 DOI: 10.2215/cjn.0000000000000228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 06/21/2023] [Indexed: 06/30/2023]
Abstract
BACKGROUND A potassium replete diet is associated with lower cardiovascular risk but may increase the risk of hyperkalemia, particularly in people using renin-angiotensin-aldosterone system inhibitors. We investigated whether intracellular uptake and potassium excretion after an acute oral potassium load depend on the accompanying anion and/or aldosterone and whether this results in altered plasma potassium change. METHODS In this placebo-controlled interventional cross-over trial including 18 healthy individuals, we studied the acute effects of one oral load of potassium citrate (40 mmol), potassium chloride (40 mmol), and placebo in random order after overnight fasting. Supplements were administered after a 6-week period with and without lisinopril pretreatment. Linear mixed effect models were used to compare blood and urine values before and after supplementation and between the interventions. Univariable linear regression was used to determine the association between baseline variables and change in blood and urine values after supplementation. RESULTS During the 4-hour follow-up, the rise in plasma potassium was similar for all interventions. After potassium citrate, both red blood cell potassium-as measure of the intracellular potassium-and transtubular potassium gradient (TTKG)-reflecting potassium secretory capacity-were higher than after potassium chloride or potassium citrate with lisinopril pretreatment. Baseline aldosterone was significantly associated with TTKG after potassium citrate, but not after potassium chloride or potassium citrate with lisinopril pretreatment. The observed TTKG change after potassium citrate was significantly associated with urine pH change during this intervention ( R =0.60, P < 0.001). CONCLUSIONS With similar plasma potassium increase, red blood cell potassium uptake and kaliuresis were higher after an acute load of potassium citrate as compared with potassium chloride alone or pretreatment with lisinopril. CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER Potassium supplementation in patients with chronic kidney disease and healthy subjects: effects on potassium and sodium balance, NL7618.
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Affiliation(s)
- Rosa D. Wouda
- Department of Internal Medicine, Section of Nephrology, Amsterdam University Medical Centers, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - Martin Gritter
- Department of Internal Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Micky Karsten
- Department of Internal Medicine, Section of Nephrology, Amsterdam University Medical Centers, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - Erik H.A. Michels
- Department of Internal Medicine, Section of Nephrology, Amsterdam University Medical Centers, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - Tamar M. Nieuweboer
- Department of Internal Medicine, Section of Nephrology, Amsterdam University Medical Centers, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - A.H. Jan Danser
- Vascular Medicine and Pharmacology, Department of Internal Medicine, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Martin H. de Borst
- Department of Internal Medicine, Division of Nephrology, University Medical Center Groningen, Groningen, The Netherlands
| | - Ewout J. Hoorn
- Department of Internal Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Joris I. Rotmans
- Department of Internal Medicine, Division of Nephrology, Leiden University Medical Center, Leiden, The Netherlands
| | - Liffert Vogt
- Department of Internal Medicine, Section of Nephrology, Amsterdam University Medical Centers, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
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9
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Kettritz R, Loffing J. Potassium homeostasis - Physiology and pharmacology in a clinical context. Pharmacol Ther 2023; 249:108489. [PMID: 37454737 DOI: 10.1016/j.pharmthera.2023.108489] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 07/03/2023] [Accepted: 07/06/2023] [Indexed: 07/18/2023]
Abstract
Membrane voltage controls the function of excitable cells and is mainly a consequence of the ratio between the extra- and intracellular potassium concentration. Potassium homeostasis is safeguarded by balancing the extra-/intracellular distribution and systemic elimination of potassium to the dietary potassium intake. These processes adjust the plasma potassium concentration between 3.5 and 4.5 mmol/L. Several genetic and acquired diseases but also pharmacological interventions cause dyskalemias that are associated with increased morbidity and mortality. The thresholds at which serum K+ not only associates but also causes increased mortality are hotly debated. We discuss physiologic, pathophysiologic, and pharmacologic aspects of potassium regulation and provide informative case vignettes. Our aim is to help clinicians, epidemiologists, and pharmacologists to understand the complexity of the potassium homeostasis in health and disease and to initiate appropriate treatment strategies in dyskalemic patients.
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Affiliation(s)
- Ralph Kettritz
- Department of Nephrology and Medical Intensive Care, Charité - Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany; Experimental and Clinical Research Center, Max Delbrück Center for Molecular Medicine in the Helmholtz Association and Charité Universitätsmedizin Berlin, Germany.
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10
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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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11
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Gallafassi E, Bezerra M, Rebouças N. Control of sodium and potassium homeostasis by renal distal convoluted tubules. Braz J Med Biol Res 2023; 56:e12392. [PMID: 36790288 PMCID: PMC9925193 DOI: 10.1590/1414-431x2023e12392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 12/17/2022] [Indexed: 02/12/2023] Open
Abstract
Distal convoluted tubules (DCT), which contain the Na-Cl cotransporter (NCC) inhibited by thiazide diuretics, undergo complex modulation to preserve Na+ and K+ homeostasis. The lysine kinases 1 and 4 (WNK1 and WNK4), identified as hyperactive in the hereditary disease pseudohypoaldosteronism type 2, are responsible for activation of NCC and consequent hypokalemia and hypertension. WNK4, highly expressed in DCT, activates the SPAK/OSR1 kinases, which phosphorylate NCC and other regulatory proteins and transporters in the distal nephron. WNK4 works as a chloride sensor through a Cl- binding site, which acts as an on/off switch at this kinase in response to changes of basolateral membrane electrical potential, the driving force of cellular Cl- efflux. High intracellular Cl- in hyperkalemia decreases NCC phosphorylation and low intracellular Cl- in hypokalemia increases NCC phosphorylation and activity, which makes plasma K+ concentration a central modulator of NCC and of K+ secretion. The WNK4 phosphorylation by cSrc or SGK1, activated by angiotensin II or aldosterone, respectively, is another relevant mechanism of NCC, ENaC, and ROMK modulation in states such as volume reduction, hyperkalemia, and hypokalemia. Loss of NCC function induces upregulation of electroneutral NaCl reabsorption by type B intercalated cells through the combined activity of pendrin and NDCBE, as demonstrated in double knockout mice (KO) animal models, Ncc/pendrin or Ncc/NDCBE. The analysis of ks-Nedd-4-2 KO animal models introduced the modulation of NEDD4-2 by intracellular Mg2+ activity as an important regulator of NCC, explaining the thiazide-induced persistent hypokalemia.
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Affiliation(s)
- E.A. Gallafassi
- Faculdade Israelita de Ciências da Saúde Albert Einstein, São Paulo, SP, Brasil
| | - M.B. Bezerra
- Faculdade Israelita de Ciências da Saúde Albert Einstein, São Paulo, SP, Brasil
| | - N.A. Rebouças
- Faculdade Israelita de Ciências da Saúde Albert Einstein, São Paulo, SP, Brasil
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12
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Zhang C, Guo J. Diverse functions of the inward-rectifying potassium channel Kir5.1 and its relationship with human diseases. Front Physiol 2023; 14:1127893. [PMID: 36923292 PMCID: PMC10008857 DOI: 10.3389/fphys.2023.1127893] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 02/15/2023] [Indexed: 03/02/2023] Open
Abstract
The inward-rectifying potassium channel subunit Kir5.1, encoded by Kcnj16, can form functional heteromeric channels (Kir4.1/5.1 and Kir4.2/5.1) with Kir4.1 (encoded by Kcnj10) or Kir4.2 (encoded by Kcnj15). It is expressed in the kidneys, pancreas, thyroid, brain, and other organs. Although Kir5.1 cannot form functional homomeric channels in most cases, an increasing number of studies in recent years have found that the functions of this subunit should not be underestimated. Kir5.1 can confer intracellular pH sensitivity to Kir4.1/5.1 channels, which can act as extracellular potassium sensors in the renal distal convoluted tubule segment. This segment plays an important role in maintaining potassium and acid-base balances. This review summarizes the various pathophysiological processes involved in Kir5.1 and the expression changes of Kir5.1 as a differentially expressed gene in various cancers, as well as describing several other disease phenotypes caused by Kir5.1 dysfunction.
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Affiliation(s)
- Chaojie Zhang
- Nephrology Research Center, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.,Institute of Nephrology, Zhengzhou University, Zhengzhou, China.,Henan Province Research Center for Kidney Disease, Zhengzhou, China.,Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Zhengzhou, China
| | - Jia Guo
- Nephrology Research Center, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.,Institute of Nephrology, Zhengzhou University, Zhengzhou, China.,Henan Province Research Center for Kidney Disease, Zhengzhou, China.,Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Zhengzhou, China
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13
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Tabibzadeh N, Crambert G. Mechanistic insights into the primary and secondary alterations of renal ion and water transport in the distal nephron. J Intern Med 2023; 293:4-22. [PMID: 35909256 PMCID: PMC10087581 DOI: 10.1111/joim.13552] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The kidneys, by equilibrating the outputs to the inputs, are essential for maintaining the constant volume, pH, and electrolyte composition of the internal milieu. Inability to do so, either because of internal kidney dysfunction (primary alteration) or because of some external factors (secondary alteration), leads to pathologies of varying severity, leading to modification of these parameters and affecting the functions of other organs. Alterations of the functions of the collecting duct (CD), the most distal part of the nephron, have been extensively studied and have led to a better diagnosis, better management of the related diseases, and the development of therapeutic tools. Thus, dysfunctions of principal cell-specific transporters such as ENaC or AQP2 or its receptors (mineralocorticoid or vasopressin receptors) caused by mutations or by compounds present in the environment (lithium, antibiotics, etc.) have been demonstrated in a variety of syndromes (Liddle, pseudohypoaldosteronism type-1, diabetes insipidus, etc.) affecting salt, potassium, and water balance. In parallel, studies on specific transporters (H+ -ATPase, anion exchanger 1) in intercalated cells have revealed the mechanisms of related tubulopathies like distal renal distal tubular acidosis or Sjögren syndrome. In this review, we will recapitulate the mechanisms of most of the primary and secondary alteration of the ion transport system of the CD to provide a better understanding of these diseases and highlight how a targeted perturbation may affect many different pathways due to the strong crosstalk and entanglements between the different actors (transporters, cell types).
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Affiliation(s)
- Nahid Tabibzadeh
- Laboratoire de Physiologie Rénale et Tubulopathies, Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université Paris Cité, Paris, France.,EMR 8228 Unité Métabolisme et Physiologie Rénale, CNRS, Paris, France.,Assistance Publique Hôpitaux de Paris, Hôpital Bichât, Paris, France
| | - Gilles Crambert
- Laboratoire de Physiologie Rénale et Tubulopathies, Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université Paris Cité, Paris, France.,EMR 8228 Unité Métabolisme et Physiologie Rénale, CNRS, Paris, France
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14
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Meng XX, Zhang H, Meng GL, Jiang SP, Duan XP, Wang WH, Wang MX. The effect of high-dietary K + (HK) on Kir4.1/Kir5.1 and ROMK in the distal convoluted tubule (DCT) is not affected by gender and Cl - content of the diet. Front Physiol 2022; 13:1039029. [PMID: 36439248 PMCID: PMC9682262 DOI: 10.3389/fphys.2022.1039029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 10/27/2022] [Indexed: 11/11/2022] Open
Abstract
Basolateral potassium channels in the distal convoluted tubule (DCT) are composed of inwardly-rectifying potassium channel 4.1 (Kir4.1) and Kir5.1. Kir4.1 interacts with Kir5.1 to form a 40 pS K+ channel which is the only type K+ channel expressed in the basolateral membrane of the DCT. Moreover, Kir4.1/Kir5.1 heterotetramer plays a key role in determining the expression and activity of thiazide-sensitive Na-Cl cotransport (NCC). In addition to Kir4.1/Kir5.1, Kir1.1 (ROMK) is expressed in the apical membrane of the late DCT (DCT2) and plays a key role in mediating epithelial Na+ channel (ENaC)-dependent K+ excretion. High dietary-K+-intake (HK) stimulates ROMK and inhibits Kir4.1/Kir5.1 in the DCT. Inhibition of Kir4.1/Kir5.1 is essential for HK-induced suppression of NCC whereas the stimulation of ROMK is important for increasing ENaC-dependent K+ excretion during HK. We have now used the patch-clamp-technique to examine whether gender and Cl- content of K+-diet affect HK-induced inhibition of basolateral Kir4.1/Kir5.1 and HK-induced stimulation of ROMK. Single-channel-recording shows that basolateral 40 pS K+ channel (Kir4.1/Kir5.1) activity of the DCT defined by NPo was 1.34 (1% KCl, normal K, NK), 0.95 (5% KCl) and 1.03 (5% K+-citrate) in male mice while it was 1.47, 1.02 and 1.05 in female mice. The whole-cell recording shows that Kir4.1/Kir5.1-mediated-K+ current of the early-DCT (DCT1) was 1,170 pA (NK), 725 pA (5% KCl) and 700 pA (5% K+-citrate) in male mice whereas it was 1,125 pA, 674 pA and 700 pA in female mice. Moreover, K+-currents (IK) reversal potential of DCT (an index of membrane potential) was -63 mV (NK), -49 mV (5% KCl) and -49 mV (5% K-citrate) in the male mice whereas it was -63 mV, -50 mV and -50 mV in female mice. Finally, TPNQ-sensitive whole-cell ROMK-currents in the DCT2 /initial-connecting tubule (CNT) were 910 pA (NK), 1,520 pA (5% KCl) and 1,540 pA (5% K+-citrate) in male mice whereas the ROMK-mediated K+ currents were 1,005 pA, 1,590 pA and 1,570 pA in female mice. We conclude that the effect of HK intake on Kir4.1/Kir5.1 of the DCT and ROMK of DCT2/CNT is similar between male and female mice. Also, Cl- content in HK diets has no effect on HK-induced inhibition of Kir4.1/Kir5.1 of the DCT and HK-induced stimulation of ROMK in DCT2/CNT.
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Affiliation(s)
- Xin-Xin Meng
- Department of Physiology, Zhuhai Campus of Zunyi Medical University, Zhuhai, China
| | - Hao Zhang
- Department of Physiology, Zhuhai Campus of Zunyi Medical University, Zhuhai, China
| | - Gui-Lin Meng
- Department of Physiology, Zhuhai Campus of Zunyi Medical University, Zhuhai, China
| | - Shao-Peng Jiang
- Department of Physiology, Zhuhai Campus of Zunyi Medical University, Zhuhai, China
| | - Xin-Peng Duan
- Department of Pharmacology, New York Medical College, Valhalla, NY, United States
| | - Wen-Hui Wang
- Department of Pharmacology, New York Medical College, Valhalla, NY, United States,*Correspondence: Ming-Xiao Wang, ; Wen-Hui Wang,
| | - Ming-Xiao Wang
- Department of Physiology, Zhuhai Campus of Zunyi Medical University, Zhuhai, China,*Correspondence: Ming-Xiao Wang, ; Wen-Hui Wang,
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15
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McDonough AA, Fenton RA. Potassium homeostasis: sensors, mediators, and targets. Pflugers Arch 2022; 474:853-867. [PMID: 35727363 PMCID: PMC10163916 DOI: 10.1007/s00424-022-02718-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Revised: 06/08/2022] [Accepted: 06/12/2022] [Indexed: 12/16/2022]
Abstract
Transmembrane potassium (K) gradients are key determinants of membrane potential that can modulate action potentials, control muscle contractility, and influence ion channel and transporter activity. Daily K intake is normally equal to the amount of K in the entire extracellular fluid (ECF) creating a critical challenge - how to maintain ECF [K] and membrane potential in a narrow range during feast and famine. Adaptations to maintain ECF [K] include sensing the K intake, sensing ECF [K] vs. desired set-point and activating mediators that regulate K distribution between ECF and ICF, and regulate renal K excretion. In this focused review, we discuss the basis of these adaptions, including (1) potential mechanisms for rapid feedforward signaling to kidney and muscle after a meal (before a rise in ECF [K]), (2) how skeletal muscles sense and respond to changes in ECF [K], (3) effects of K on aldosterone biosynthesis, and (4) how the kidney responds to changes in ECF [K] to modify K excretion. The concepts of sexual dimorphisms in renal K handling adaptation are introduced, and the molecular mechanisms that can account for the benefits of a K-rich diet to maintain cardiovascular health are discussed. Although the big picture of K homeostasis is becoming more clear, we also highlight significant pieces of the puzzle that remain to be solved, including knowledge gaps in our understanding of initiating signals, sensors and their connection to homeostatic adjustments of ECF [K].
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Affiliation(s)
- Alicia A McDonough
- Department of Physiology and Neuroscience, University of Southern California Keck School of Medicine, Los Angeles, CA, USA.
| | - Robert A Fenton
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
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16
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McClenahan SJ, Kent CN, Kharade SV, Isaeva E, Williams JC, Han C, Terker A, Gresham R, Lazarenko RM, Days EL, Romaine IM, Bauer JA, Boutaud O, Sulikowski GA, Harris R, Weaver CD, Staruschenko A, Lindsley CW, Denton JS. VU6036720: The First Potent and Selective In Vitro Inhibitor of Heteromeric Kir4.1/5.1 Inward Rectifier Potassium Channels. Mol Pharmacol 2022; 101:357-370. [PMID: 35246480 PMCID: PMC9092466 DOI: 10.1124/molpharm.121.000464] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 02/14/2022] [Indexed: 01/14/2023] Open
Abstract
Heteromeric Kir4.1/Kir5.1 (KCNJ10/KCNJ16) inward rectifier potassium (Kir) channels play key roles in the brain and kidney, but pharmacological tools for probing their physiology and therapeutic potential have not been developed. Here, we report the discovery, in a high-throughput screening of 80,475 compounds, of the moderately potent and selective inhibitor VU0493690, which we selected for characterization and chemical optimization. VU0493690 concentration-dependently inhibits Kir4.1/5.1 with an IC50 of 0.96 μM and exhibits at least 10-fold selectivity over Kir4.1 and ten other Kir channels. Multidimensional chemical optimization of VU0493690 led to the development of VU6036720, the most potent (IC50 = 0.24 μM) and selective (>40-fold over Kir4.1) Kir4.1/5.1 inhibitor reported to date. Cell-attached patch single-channel recordings revealed that VU6036720 inhibits Kir4.1/5.1 activity through a reduction of channel open-state probability and single-channel current amplitude. Elevating extracellular potassium ion by 20 mM shifted the IC50 6.8-fold, suggesting that VU6036720 is a pore blocker that binds in the ion-conduction pathway. Mutation of the "rectification controller" asparagine 161 to glutamate (N161E), which is equivalent to small-molecule binding sites in other Kir channels, led to a strong reduction of inhibition by VU6036720. Renal clearance studies in mice failed to show a diuretic response that would be consistent with inhibition of Kir4.1/5.1 in the renal tubule. Drug metabolism and pharmacokinetics profiling revealed that high VU6036720 clearance and plasma protein binding may prevent target engagement in vivo. In conclusion, VU6036720 represents the current state-of-the-art Kir4.1/5.1 inhibitor that should be useful for probing the functions of Kir4.1/5.1 in vitro and ex vivo. SIGNIFICANCE STATEMENT: Heteromeric inward rectifier potassium (Kir) channels comprising Kir4.1 and Kir5.1 subunits play important roles in renal and neural physiology and may represent inhibitory drug targets for hypertension and edema. Herein, we employ high-throughput compound library screening, patch clamp electrophysiology, and medicinal chemistry to develop and characterize the first potent and specific in vitro inhibitor of Kir4.1/5.1, VU6036720, which provides proof-of-concept that drug-like inhibitors of this channel may be developed.
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Affiliation(s)
- Samantha J McClenahan
- Departments of Anesthesiology (S.J.M., S.V.K., R.G., R.M.L., J.S.D.), Biochemistry (J.A.B.), Chemistry (C.N.K., J.C.W., I.M.R., C.D.W., G.A.S., C.W.L.), Pharmacology (E.L.D., C.D.W., C.W.L., C.H., O.B., J.S.D.), and Nephrology (A.T., R.H.), and Vanderbilt Institute of Chemical Biology (J.A.B., G.S., C.D.W., C.W.L., J.S.D.), Vanderbilt University, Nashville, Tennessee; Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin (E.I.); and Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida (A.S.)
| | - Caitlin N Kent
- Departments of Anesthesiology (S.J.M., S.V.K., R.G., R.M.L., J.S.D.), Biochemistry (J.A.B.), Chemistry (C.N.K., J.C.W., I.M.R., C.D.W., G.A.S., C.W.L.), Pharmacology (E.L.D., C.D.W., C.W.L., C.H., O.B., J.S.D.), and Nephrology (A.T., R.H.), and Vanderbilt Institute of Chemical Biology (J.A.B., G.S., C.D.W., C.W.L., J.S.D.), Vanderbilt University, Nashville, Tennessee; Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin (E.I.); and Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida (A.S.)
| | - Sujay V Kharade
- Departments of Anesthesiology (S.J.M., S.V.K., R.G., R.M.L., J.S.D.), Biochemistry (J.A.B.), Chemistry (C.N.K., J.C.W., I.M.R., C.D.W., G.A.S., C.W.L.), Pharmacology (E.L.D., C.D.W., C.W.L., C.H., O.B., J.S.D.), and Nephrology (A.T., R.H.), and Vanderbilt Institute of Chemical Biology (J.A.B., G.S., C.D.W., C.W.L., J.S.D.), Vanderbilt University, Nashville, Tennessee; Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin (E.I.); and Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida (A.S.)
| | - Elena Isaeva
- Departments of Anesthesiology (S.J.M., S.V.K., R.G., R.M.L., J.S.D.), Biochemistry (J.A.B.), Chemistry (C.N.K., J.C.W., I.M.R., C.D.W., G.A.S., C.W.L.), Pharmacology (E.L.D., C.D.W., C.W.L., C.H., O.B., J.S.D.), and Nephrology (A.T., R.H.), and Vanderbilt Institute of Chemical Biology (J.A.B., G.S., C.D.W., C.W.L., J.S.D.), Vanderbilt University, Nashville, Tennessee; Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin (E.I.); and Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida (A.S.)
| | - Jade C Williams
- Departments of Anesthesiology (S.J.M., S.V.K., R.G., R.M.L., J.S.D.), Biochemistry (J.A.B.), Chemistry (C.N.K., J.C.W., I.M.R., C.D.W., G.A.S., C.W.L.), Pharmacology (E.L.D., C.D.W., C.W.L., C.H., O.B., J.S.D.), and Nephrology (A.T., R.H.), and Vanderbilt Institute of Chemical Biology (J.A.B., G.S., C.D.W., C.W.L., J.S.D.), Vanderbilt University, Nashville, Tennessee; Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin (E.I.); and Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida (A.S.)
| | - Changho Han
- Departments of Anesthesiology (S.J.M., S.V.K., R.G., R.M.L., J.S.D.), Biochemistry (J.A.B.), Chemistry (C.N.K., J.C.W., I.M.R., C.D.W., G.A.S., C.W.L.), Pharmacology (E.L.D., C.D.W., C.W.L., C.H., O.B., J.S.D.), and Nephrology (A.T., R.H.), and Vanderbilt Institute of Chemical Biology (J.A.B., G.S., C.D.W., C.W.L., J.S.D.), Vanderbilt University, Nashville, Tennessee; Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin (E.I.); and Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida (A.S.)
| | - Andrew Terker
- Departments of Anesthesiology (S.J.M., S.V.K., R.G., R.M.L., J.S.D.), Biochemistry (J.A.B.), Chemistry (C.N.K., J.C.W., I.M.R., C.D.W., G.A.S., C.W.L.), Pharmacology (E.L.D., C.D.W., C.W.L., C.H., O.B., J.S.D.), and Nephrology (A.T., R.H.), and Vanderbilt Institute of Chemical Biology (J.A.B., G.S., C.D.W., C.W.L., J.S.D.), Vanderbilt University, Nashville, Tennessee; Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin (E.I.); and Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida (A.S.)
| | - Robert Gresham
- Departments of Anesthesiology (S.J.M., S.V.K., R.G., R.M.L., J.S.D.), Biochemistry (J.A.B.), Chemistry (C.N.K., J.C.W., I.M.R., C.D.W., G.A.S., C.W.L.), Pharmacology (E.L.D., C.D.W., C.W.L., C.H., O.B., J.S.D.), and Nephrology (A.T., R.H.), and Vanderbilt Institute of Chemical Biology (J.A.B., G.S., C.D.W., C.W.L., J.S.D.), Vanderbilt University, Nashville, Tennessee; Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin (E.I.); and Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida (A.S.)
| | - Roman M Lazarenko
- Departments of Anesthesiology (S.J.M., S.V.K., R.G., R.M.L., J.S.D.), Biochemistry (J.A.B.), Chemistry (C.N.K., J.C.W., I.M.R., C.D.W., G.A.S., C.W.L.), Pharmacology (E.L.D., C.D.W., C.W.L., C.H., O.B., J.S.D.), and Nephrology (A.T., R.H.), and Vanderbilt Institute of Chemical Biology (J.A.B., G.S., C.D.W., C.W.L., J.S.D.), Vanderbilt University, Nashville, Tennessee; Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin (E.I.); and Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida (A.S.)
| | - Emily L Days
- Departments of Anesthesiology (S.J.M., S.V.K., R.G., R.M.L., J.S.D.), Biochemistry (J.A.B.), Chemistry (C.N.K., J.C.W., I.M.R., C.D.W., G.A.S., C.W.L.), Pharmacology (E.L.D., C.D.W., C.W.L., C.H., O.B., J.S.D.), and Nephrology (A.T., R.H.), and Vanderbilt Institute of Chemical Biology (J.A.B., G.S., C.D.W., C.W.L., J.S.D.), Vanderbilt University, Nashville, Tennessee; Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin (E.I.); and Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida (A.S.)
| | - Ian M Romaine
- Departments of Anesthesiology (S.J.M., S.V.K., R.G., R.M.L., J.S.D.), Biochemistry (J.A.B.), Chemistry (C.N.K., J.C.W., I.M.R., C.D.W., G.A.S., C.W.L.), Pharmacology (E.L.D., C.D.W., C.W.L., C.H., O.B., J.S.D.), and Nephrology (A.T., R.H.), and Vanderbilt Institute of Chemical Biology (J.A.B., G.S., C.D.W., C.W.L., J.S.D.), Vanderbilt University, Nashville, Tennessee; Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin (E.I.); and Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida (A.S.)
| | - Joshua A Bauer
- Departments of Anesthesiology (S.J.M., S.V.K., R.G., R.M.L., J.S.D.), Biochemistry (J.A.B.), Chemistry (C.N.K., J.C.W., I.M.R., C.D.W., G.A.S., C.W.L.), Pharmacology (E.L.D., C.D.W., C.W.L., C.H., O.B., J.S.D.), and Nephrology (A.T., R.H.), and Vanderbilt Institute of Chemical Biology (J.A.B., G.S., C.D.W., C.W.L., J.S.D.), Vanderbilt University, Nashville, Tennessee; Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin (E.I.); and Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida (A.S.)
| | - Olivier Boutaud
- Departments of Anesthesiology (S.J.M., S.V.K., R.G., R.M.L., J.S.D.), Biochemistry (J.A.B.), Chemistry (C.N.K., J.C.W., I.M.R., C.D.W., G.A.S., C.W.L.), Pharmacology (E.L.D., C.D.W., C.W.L., C.H., O.B., J.S.D.), and Nephrology (A.T., R.H.), and Vanderbilt Institute of Chemical Biology (J.A.B., G.S., C.D.W., C.W.L., J.S.D.), Vanderbilt University, Nashville, Tennessee; Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin (E.I.); and Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida (A.S.)
| | - Gary A Sulikowski
- Departments of Anesthesiology (S.J.M., S.V.K., R.G., R.M.L., J.S.D.), Biochemistry (J.A.B.), Chemistry (C.N.K., J.C.W., I.M.R., C.D.W., G.A.S., C.W.L.), Pharmacology (E.L.D., C.D.W., C.W.L., C.H., O.B., J.S.D.), and Nephrology (A.T., R.H.), and Vanderbilt Institute of Chemical Biology (J.A.B., G.S., C.D.W., C.W.L., J.S.D.), Vanderbilt University, Nashville, Tennessee; Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin (E.I.); and Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida (A.S.)
| | - Raymond Harris
- Departments of Anesthesiology (S.J.M., S.V.K., R.G., R.M.L., J.S.D.), Biochemistry (J.A.B.), Chemistry (C.N.K., J.C.W., I.M.R., C.D.W., G.A.S., C.W.L.), Pharmacology (E.L.D., C.D.W., C.W.L., C.H., O.B., J.S.D.), and Nephrology (A.T., R.H.), and Vanderbilt Institute of Chemical Biology (J.A.B., G.S., C.D.W., C.W.L., J.S.D.), Vanderbilt University, Nashville, Tennessee; Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin (E.I.); and Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida (A.S.)
| | - C David Weaver
- Departments of Anesthesiology (S.J.M., S.V.K., R.G., R.M.L., J.S.D.), Biochemistry (J.A.B.), Chemistry (C.N.K., J.C.W., I.M.R., C.D.W., G.A.S., C.W.L.), Pharmacology (E.L.D., C.D.W., C.W.L., C.H., O.B., J.S.D.), and Nephrology (A.T., R.H.), and Vanderbilt Institute of Chemical Biology (J.A.B., G.S., C.D.W., C.W.L., J.S.D.), Vanderbilt University, Nashville, Tennessee; Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin (E.I.); and Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida (A.S.)
| | - Alexander Staruschenko
- Departments of Anesthesiology (S.J.M., S.V.K., R.G., R.M.L., J.S.D.), Biochemistry (J.A.B.), Chemistry (C.N.K., J.C.W., I.M.R., C.D.W., G.A.S., C.W.L.), Pharmacology (E.L.D., C.D.W., C.W.L., C.H., O.B., J.S.D.), and Nephrology (A.T., R.H.), and Vanderbilt Institute of Chemical Biology (J.A.B., G.S., C.D.W., C.W.L., J.S.D.), Vanderbilt University, Nashville, Tennessee; Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin (E.I.); and Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida (A.S.)
| | - Craig W Lindsley
- Departments of Anesthesiology (S.J.M., S.V.K., R.G., R.M.L., J.S.D.), Biochemistry (J.A.B.), Chemistry (C.N.K., J.C.W., I.M.R., C.D.W., G.A.S., C.W.L.), Pharmacology (E.L.D., C.D.W., C.W.L., C.H., O.B., J.S.D.), and Nephrology (A.T., R.H.), and Vanderbilt Institute of Chemical Biology (J.A.B., G.S., C.D.W., C.W.L., J.S.D.), Vanderbilt University, Nashville, Tennessee; Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin (E.I.); and Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida (A.S.)
| | - Jerod S Denton
- Departments of Anesthesiology (S.J.M., S.V.K., R.G., R.M.L., J.S.D.), Biochemistry (J.A.B.), Chemistry (C.N.K., J.C.W., I.M.R., C.D.W., G.A.S., C.W.L.), Pharmacology (E.L.D., C.D.W., C.W.L., C.H., O.B., J.S.D.), and Nephrology (A.T., R.H.), and Vanderbilt Institute of Chemical Biology (J.A.B., G.S., C.D.W., C.W.L., J.S.D.), Vanderbilt University, Nashville, Tennessee; Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin (E.I.); and Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida (A.S.)
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17
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Svendsen SL, Kornvig S, Berg P, Jensen IS, Araujo IBBA, Larsen CK, Leipziger J, Sørensen MV. Dietary K + acts as a genuine diuretic. Acta Physiol (Oxf) 2022; 234:e13762. [PMID: 34984847 DOI: 10.1111/apha.13762] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 11/29/2021] [Accepted: 01/01/2022] [Indexed: 12/11/2022]
Abstract
K+ balance in mammals relies on regulated renal K+ excretion matching unregulated fluctuating K+ intake. Upon a K+ rich meal, rapid and powerful K+ excretion is needed. Renal K+ secretion is stimulated by the increased tubular flow. We speculated that high K+ intake acutely increases urinary flow to stimulate K+ excretion. METHODS Mice were K+ challenged through diets or gavage. Post K+ loading urinary output, osmolarity, [K+ ]u , [Na+ ]u , plasma osmolarity, [copeptin]p , [K+ ]p , and [Na+ ]p were measured. To locate the mechanism of K+ -induced diuresis in the glomerular/tubular system we measured creatinine excretion and assessed functional transport in isolated perfused TALs and CDs during an acute [K+ ]bl switch from 3.6 to 6.5 mM. Molecular adaptations of transport proteins involved in water reabsorption were investigated by immunoblotting. RESULTS (1) Mice switched from a 1% to 2% K+ diet increased diuresis within 12 hours and reciprocally reduced diuresis when switched from 1% to 0.01% K+ diet. (2) A single K+ gavage load, corresponding to 25%-50% of daily K+ intake, induced 100% increase in diuresis within 30 minutes. This occurred despite augmented plasma osmolarity and AVP synthesis. (3) K+ gavage did not change GFR. (4) In isolated perfused TALs, shifting [K+ ]bl from 3.6 to 6.5 mM did not affect AVP-induced NaCl transport. (5) In sharp contrast, in isolated perfused CDs, shifting [K+ ]bl from 3.6 to 6.5 mM markedly reduced CD AVP sensitivity, ie inhibited water absorption. CONCLUSION Dietary K+ loading induces a rapidly on-setting diuresis. The mechanism of K+ -induced diuresis involves desensitization of the CD to AVP.
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Affiliation(s)
- Samuel L. Svendsen
- Department of Biomedicine, Physiology, Health Aarhus University Aarhus C Denmark
| | - Simon Kornvig
- Department of Biomedicine, Physiology, Health Aarhus University Aarhus C Denmark
| | - Peder Berg
- Department of Biomedicine, Physiology, Health Aarhus University Aarhus C Denmark
| | - Iben S. Jensen
- Department of Biomedicine, Physiology, Health Aarhus University Aarhus C Denmark
| | | | - Casper K. Larsen
- Department of Biomedicine, Physiology, Health Aarhus University Aarhus C Denmark
| | - Jens Leipziger
- Department of Biomedicine, Physiology, Health Aarhus University Aarhus C Denmark
| | - Mads V. Sørensen
- Department of Biomedicine, Physiology, Health Aarhus University Aarhus C Denmark
- Aarhus Institute for Advanced Studies (AIAS) Aarhus University Aarhus C Denmark
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18
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Zapf AM, Grimm PR, Al-Qusairi L, Delpire E, Welling PA. Low Salt Delivery Triggers Autocrine Release of Prostaglandin E2 From the Aldosterone-Sensitive Distal Nephron in Familial Hyperkalemic Hypertension Mice. Front Physiol 2022; 12:787323. [PMID: 35069250 PMCID: PMC8770744 DOI: 10.3389/fphys.2021.787323] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 11/19/2021] [Indexed: 11/13/2022] Open
Abstract
Aberrant activation of with-no-lysine kinase (WNK)-STE20/SPS1-related proline-alanine-rich protein kinase (SPAK) kinase signaling in the distal convoluted tubule (DCT) causes unbridled activation of the thiazide-sensitive sodium chloride cotransporter (NCC), leading to familial hyperkalemic hypertension (FHHt) in humans. Studies in FHHt mice engineered to constitutively activate SPAK specifically in the DCT (CA-SPAK mice) revealed maladaptive remodeling of the aldosterone sensitive distal nephron (ASDN), characterized by decrease in the potassium excretory channel, renal outer medullary potassium (ROMK), and epithelial sodium channel (ENaC), that contributes to the hyperkalemia. The mechanisms by which NCC activation in DCT promotes remodeling of connecting tubule (CNT) are unknown, but paracrine communication and reduced salt delivery to the ASDN have been suspected. Here, we explore the involvement of prostaglandin E2 (PGE2). We found that PGE2 and the terminal PGE2 synthase, mPGES1, are increased in kidney cortex of CA-SPAK mice, compared to control or SPAK KO mice. Hydrochlorothiazide (HCTZ) reduced PGE2 to control levels, indicating increased PGE2 synthesis is dependent on increased NCC activity. Immunolocalization studies revealed mPGES1 is selectively increased in the CNT of CA-SPAK mice, implicating low salt-delivery to ASDN as the trigger. Salt titration studies in an in vitro ASDN cell model, mouse CCD cell (mCCD-CL1), confirmed PGE2 synthesis is activated by low salt, and revealed that response is paralleled by induction of mPGES1 gene expression. Finally, inhibition of the PGE2 receptor, EP1, in CA-SPAK mice partially restored potassium homeostasis as it partially rescued ROMK protein abundance, but not ENaC. Together, these data indicate low sodium delivery to the ASDN activates PGE2 synthesis and this inhibits ROMK through autocrine activation of the EP1 receptor. These findings provide new insights into the mechanism by which activation of sodium transport in the DCT causes remodeling of the ASDN.
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Affiliation(s)
- Ava M Zapf
- Molecular Medicine, Graduate Program in Life Sciences, University of Maryland Medical School, Baltimore, MD, United States
| | - Paul R Grimm
- Department of Medicine, Johns Hopkins University, Baltimore, MD, United States
| | - Lama Al-Qusairi
- Department of Medicine, Johns Hopkins University, Baltimore, MD, United States
| | - Eric Delpire
- Department of Anesthesiology, Vanderbilt University Medical School, Nashville, TN, United States
| | - Paul A Welling
- Department of Medicine, Johns Hopkins University, Baltimore, MD, United States.,Department of Physiology, Johns Hopkins University, Baltimore, MD, United States
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19
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Polidoro JZ, Luchi WM, Seguro AC, Malnic G, Girardi ACC. Paracrine and endocrine regulation of renal potassium secretion. Am J Physiol Renal Physiol 2022; 322:F360-F377. [DOI: 10.1152/ajprenal.00251.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The seminal studies conducted by Giebisch and colleagues in the 1960s paved the way for understanding the renal mechanisms involved in K+ homeostasis. It was demonstrated that differential handling of K+ in the distal segments of the nephron is crucial for proper K+ balance. Although aldosterone had been classically ascribed as the major ion transport regulator in the distal nephron, thereby contributing to K+ homeostasis, it became clear that aldosterone per se could not explain the kidney's ability to modulate kaliuresis in both acute and chronic settings. The existence of alternative kaliuretic and antikaliuretic mechanisms was suggested by physiological studies in the 1980s but only gained form and shape with the advent of molecular biology. It is now established that the kidneys recruit several endocrine and paracrine mechanisms for adequate kaliuretic response. These mechanisms include the direct effects of peritubular K+, a gut-kidney regulatory axis sensing dietary K+ levels, the kidney secretion of kallikrein during postprandial periods, the upregulation of angiotensin II receptors in the distal nephron during chronic changes in the K+ diet, and the local increase of prostaglandins by low K+ diet. This review discusses recent advances in the understanding of endocrine and paracrine mechanisms underlying the modulation of K+ secretion and how these mechanisms impact kaliuresis and K+ balance. We also highlight important unknowns about the regulation of renal K+ excretion under physiological circumstances.
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Affiliation(s)
- Juliano Z. Polidoro
- Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil
| | - Weverton Machado Luchi
- Department of Internal Medicine, Federal University of Espírito Santo (UFES), Vitória, Espírito Santo, Brazil
| | - Antonio Carlos Seguro
- Department of Nephrology (LIM 12), University of São Paulo Medical School, São Paulo, São Paulo, Brazil
| | - Gerhard Malnic
- Department of Physiology and Biophysics, University of São Paulo Medical School, São Paulo, Brazil
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20
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Preston RA, Afshartous D, Caizapanta EV, Materson BJ, Rodco R, Alonso E, Alonso AB. Characterization of Potassium-Induced Natriuresis in Hypertensive Postmenopausal Women During Both Low and High Sodium Intake. Hypertension 2022; 79:813-826. [PMID: 35045721 DOI: 10.1161/hypertensionaha.121.18392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Potassium-induced natriuresis may contribute to the beneficial effects of potassium on blood pressure but has not been well-characterized in human postmenopausal hypertension. We determined the time course and magnitude of potassium-induced natriuresis and kaliuresis compared with hydrochlorothiazide in 19 hypertensive Hispanic postmenopausal women. We also determined the modulating effects of sodium intake, sodium-sensitivity, and activity of the thiazide-sensitive NCC (sodium-chloride cotransporter). METHODS Sixteen-day inpatient confinement: 8 days low sodium followed by 8 days high sodium intake. During both periods, we determined sodium and potassium excretion following 35 mmol oral KCl versus 50 mg hydrochlorothiazide. We determined sodium-sensitivity as change in 24-hour systolic pressure from low to high sodium. We determined NCC activity by standard thiazide-sensitivity test. RESULTS Steady-state sodium intake was the key determinant of potassium-induced natriuresis. During low sodium intake, sodium excretion was low and did not increase following 35 mmol KCl indicating continued sodium conservation. Conversely, during high sodium intake, sodium excretion increased sharply following 35 mmol KCl to ≈37% of that produced by hydrochlorothiazide. Under both low and high sodium intake, 35 mmol potassium was mostly excreted within 5 hours, accompanied by a sodium load reflecting the steady-state sodium intake, consistent with independent regulation of sodium/potassium excretion in the human distal nephron. CONCLUSIONS Potassium-induced natriuresis was not greater in sodium-sensitive versus sodium-resistant hypertensives or hypertensives with higher versus lower basal NCC activity. We studied an acute KCl challenge. It remains to further characterize potassium-induced natriuresis during chronic potassium increase and when potassium is administered a complex potassium-containing meal.
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Affiliation(s)
- Richard A Preston
- Division of Clinical Pharmacology, Department of Medicine, Miller School of Medicine University of Miami. Clinical Pharmacology Research Unit, Division of Clinical Pharmacology, Department of Medicine, Miller School of Medicine, University of Miami, FL. (R.A.P., D.A., E.V.C., B.J.M., R.R., E.A., A.B.A.).,University of Miami Clinical and Translational Science Institutes (CTSI), Miller School of Medicine, University of Miami, FL. (R.A.P.).,The Peggy and Harold Katz Family Drug Discovery center, Miller School of Medicine, University of Miami, FL. (R.A.P.)
| | - David Afshartous
- Division of Clinical Pharmacology, Department of Medicine, Miller School of Medicine University of Miami. Clinical Pharmacology Research Unit, Division of Clinical Pharmacology, Department of Medicine, Miller School of Medicine, University of Miami, FL. (R.A.P., D.A., E.V.C., B.J.M., R.R., E.A., A.B.A.)
| | - Evelyn V Caizapanta
- Division of Clinical Pharmacology, Department of Medicine, Miller School of Medicine University of Miami. Clinical Pharmacology Research Unit, Division of Clinical Pharmacology, Department of Medicine, Miller School of Medicine, University of Miami, FL. (R.A.P., D.A., E.V.C., B.J.M., R.R., E.A., A.B.A.)
| | - Barry J Materson
- Division of Clinical Pharmacology, Department of Medicine, Miller School of Medicine University of Miami. Clinical Pharmacology Research Unit, Division of Clinical Pharmacology, Department of Medicine, Miller School of Medicine, University of Miami, FL. (R.A.P., D.A., E.V.C., B.J.M., R.R., E.A., A.B.A.)
| | - Rolando Rodco
- Division of Clinical Pharmacology, Department of Medicine, Miller School of Medicine University of Miami. Clinical Pharmacology Research Unit, Division of Clinical Pharmacology, Department of Medicine, Miller School of Medicine, University of Miami, FL. (R.A.P., D.A., E.V.C., B.J.M., R.R., E.A., A.B.A.)
| | - Eileen Alonso
- Division of Clinical Pharmacology, Department of Medicine, Miller School of Medicine University of Miami. Clinical Pharmacology Research Unit, Division of Clinical Pharmacology, Department of Medicine, Miller School of Medicine, University of Miami, FL. (R.A.P., D.A., E.V.C., B.J.M., R.R., E.A., A.B.A.)
| | - Alberto B Alonso
- Division of Clinical Pharmacology, Department of Medicine, Miller School of Medicine University of Miami. Clinical Pharmacology Research Unit, Division of Clinical Pharmacology, Department of Medicine, Miller School of Medicine, University of Miami, FL. (R.A.P., D.A., E.V.C., B.J.M., R.R., E.A., A.B.A.)
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21
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Reyes JV, Medina PMB. Renal calcium and magnesium handling in Gitelman syndrome. Am J Transl Res 2022; 14:1-19. [PMID: 35173827 PMCID: PMC8829599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 11/24/2021] [Indexed: 06/14/2023]
Abstract
Gitelman syndrome (GS) is an autosomal recessive salt-losing tubulopathy caused by biallelic inactivating mutations in the SLC12A3 gene. This gene encodes the thiazide-sensitive sodium-chloride cotransporter (NCC) which is exclusively expressed in the distal convoluted tubules (DCT). GS patients classically present with hypokalemic metabolic alkalosis with hypocalciuria and hypomagnesemia. While hypokalemia and metabolic alkalosis are easily explained by effects of the genotypic defect in GS, the mechanisms by which hypomagnesemia and hypocalciuria develop in GS are poorly understood. In this review, we aim to achieve three major objectives. First, present a concise discussion about current understanding on physiologic calcium and magnesium handling in the DCT. Second, integrate expression data from studies on calciotropic and magnesiotropic proteins relevant to the GS disease state. Lastly, provide insights into the possible mechanisms of calcium-magnesium crosstalk relating to the co-occurrence of hypocalciuria and hypomagnesemia in GS models. Our analyses highlight specific areas of study that are valuable in elucidating possible molecular pathways of hypocalciuria and hypomagnesemia in GS.
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Affiliation(s)
- Jeremiah V Reyes
- Biological Models Laboratory, Department of Biochemistry and Molecular Biology, College of Medicine, University of the Philippines Manila Ermita, Manila 1000, Philippines
| | - Paul Mark B Medina
- Biological Models Laboratory, Department of Biochemistry and Molecular Biology, College of Medicine, University of the Philippines Manila Ermita, Manila 1000, Philippines
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22
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Nesterov V, Bertog M, Korbmacher C. High baseline ROMK activity in the mouse late distal convoluted and early connecting tubule probably contributes to aldosterone-independent K + secretion. Am J Physiol Renal Physiol 2022; 322:F42-F54. [PMID: 34843658 DOI: 10.1152/ajprenal.00252.2021] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 11/18/2021] [Indexed: 11/22/2022] Open
Abstract
The renal outer medullary K+ channel (ROMK) is colocalized with the epithelial Na+ channel (ENaC) in the late distal convoluted tubule (DCT2), connecting tubule (CNT), and cortical collecting duct (CCD). ENaC-mediated Na+ absorption generates the electrical driving force for ROMK-mediated tubular K+ secretion, which is critically important for maintaining renal K+ homeostasis. ENaC activity is aldosterone dependent in the late CNT and early CCD (CNT/CCD) but aldosterone independent in the DCT2 and early CNT (DCT2/CNT). This suggests that under baseline conditions with low plasma aldosterone, ROMK-mediated K+ secretion mainly occurs in the DCT2/CNT. Therefore, we hypothesized that baseline ROMK activity is higher in the DCT2/CNT than in the CNT/CCD. To test this hypothesis, patch-clamp experiments were performed in the DCT2/CNT and CNT/CCD microdissected from mice maintained on a standard diet. In single-channel recordings from outside-out patches, we detected typical ROMK channel activity in both the DCT2/CNT and CNT/CCD and confirmed that ROMK is the predominant K+ channel in the apical membrane. Amiloride-sensitive and tertiapin-sensitive whole-cell currents were determined to assess ENaC and ROMK activity, respectively. As expected, baseline amiloride-sensitive current was high in the DCT2/CNT (∼370 pA) but low in the CNT/CCD (∼60 pA). Importantly, tertiapin-sensitive current was significantly higher in the DCT2/CNT than in the CNT/CCD (∼810 vs. ∼350 pA). We conclude that high ROMK activity in the DCT2/CNT is critical for aldosterone-independent renal K+ secretion under baseline conditions. A low-K+ diet significantly reduced ENaC but not ROMK activity in the DCT2/CNT. This suggests that modifying ENaC activity in the DCT2/CNT plays a key regulatory role in adjusting renal K+ excretion to dietary K+ intake.NEW & NOTEWORTHY ROMK-mediated renal K+ secretion is essential for maintaining K+ balance and requires a lumen negative transepithelial potential critically dependent on ENaC activity. Using microdissected distal mouse tubules, we demonstrated that baseline apical ROMK activity is high in the DCT2/CNT. Aldosterone-independent baseline ENaC activity is also high in the DCT2/CNT and downregulated by a low-K+ diet, which highlights the important role of the DCT2/CNT in regulating K+ secretion in an aldosterone-independent manner.
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Affiliation(s)
- Viatcheslav Nesterov
- Institut für Zelluläre und Molekulare Physiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Marko Bertog
- Institut für Zelluläre und Molekulare Physiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Christoph Korbmacher
- Institut für Zelluläre und Molekulare Physiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
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23
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Claverie-Martin F, Perdomo-Ramirez A, Garcia-Nieto V. Hereditary kidney diseases associated with hypomagnesemia. Kidney Res Clin Pract 2021; 40:512-526. [PMID: 34784661 PMCID: PMC8685365 DOI: 10.23876/j.krcp.21.112] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 06/20/2021] [Indexed: 11/04/2022] Open
Abstract
In the kidney, a set of proteins expressed in the epithelial cells of the thick ascending loop of Henle and the distal convoluted tubule directly or indirectly play important roles in the regulation of serum magnesium levels. Magnesium reabsorption in the thick ascending loop of Henle occurs through a passive paracellular pathway, while in the distal convoluted tubule, the final magnesium concentration is established through an active transcellular pathway. The players involved in magnesium reabsorption include proteins with diverse functions including tight junction proteins, cation and anion channels, sodium chloride cotransporter, calcium-sensing receptor, epidermal growth factor, cyclin M2, sodium potassium adenosine triphosphatase subunits, transcription factors, a serine protease, and proteins involved in mitochondrial function. Mutations in the genes that encode these proteins impair their function and cause different rare diseases associated with hypomagnesemia, which may lead to muscle cramps, fatigue, epileptic seizures, intellectual disability, cardiac arrhythmias, and chronic kidney disease. The purpose of this review is to describe the clinical and genetic characteristics of these hereditary kidney diseases and the current research findings on the pathophysiological basis of these diseases.
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Affiliation(s)
- Felix Claverie-Martin
- Unidad de Investigación, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain
| | - Ana Perdomo-Ramirez
- Unidad de Investigación, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain
| | - Victor Garcia-Nieto
- Unidad de Nefrología Pediátrica, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain
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24
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Hyndman KA, Isaeva E, Palygin O, Mendoza LD, Rodan AR, Staruschenko A, Pollock JS. Role of collecting duct principal cell NOS1β in sodium and potassium homeostasis. Physiol Rep 2021; 9:e15080. [PMID: 34665521 PMCID: PMC8525323 DOI: 10.14814/phy2.15080] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 09/15/2021] [Accepted: 09/27/2021] [Indexed: 12/15/2022] Open
Abstract
The nitric oxide (NO)-generating enzyme, NO synthase-1β (NOS1β), is essential for sodium (Na+ ) homeostasis and blood pressure control. We previously showed that collecting duct principal cell NOS1β is critical for inhibition of the epithelial sodium channel (ENaC) during high Na+ intake. Previous studies on freshly isolated cortical collecting ducts (CCD) demonstrated that exogenous NO promotes basolateral potassium (K+ ) conductance through basolateral channels, presumably Kir 4.1 (Kcnj10) and Kir 5.1 (Kcnj16). We, therefore, investigated the effects of NOS1β knockout on Kir 4.1/Kir 5.1 channel activity. Indeed, in CHO cells overexpressing NOS1β and Kir 4.1/Kir 5.1, the inhibition of NO signaling decreased channel activity. Male littermate control and principal cell NOS1β knockout mice (CDNOS1KO) on a 7-day, 4% NaCl diet (HSD) were used to detect changes in basolateral K+ conductance. We previously demonstrated that CDNOS1KO mice have high circulating aldosterone despite a high-salt diet and appropriately suppressed renin. We observed greater Kir 4.1 cortical abundance and significantly greater Kir 4.1/Kir 5.1 single-channel activity in the principal cells from CDNOS1KO mice. Moreover, blocking aldosterone action with in vivo spironolactone treatment resulted in lower Kir 4.1 abundance and greater plasma K+ in the CDNOS1KO mice compared to controls. Lowering K+ content in the HSD prevented the high aldosterone and greater plasma Na+ of CDNOS1KO mice and normalized Kir 4.1 abundance. We conclude that during chronic HSD, lack of NOS1β leads to increased plasma K+ , enhanced circulating aldosterone, and activation of ENaC and Kir 4.1/Kir 5.1 channels. Thus, principal cell NOS1β is required for the regulation of both Na+ and K+ by the kidney.
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Affiliation(s)
- Kelly A. Hyndman
- Department of MedicineDivision of NephrologySection of Cardio‐Renal Physiology and MedicineUniversity of Alabama at BirminghamBirminghamAlabamaUSA
| | - Elena Isaeva
- Department of Cellular Biology, Neurobiology and AnatomyMedical College of WisconsinMilwaukeeWisconsinUSA
| | - Oleg Palygin
- Division of NephrologyDepartment of MedicineMedical University of South CarolinaCharlestonSouth CarolinaUSA
| | - Luciano D. Mendoza
- Department of MedicineDivision of NephrologySection of Cardio‐Renal Physiology and MedicineUniversity of Alabama at BirminghamBirminghamAlabamaUSA
| | - Aylin R. Rodan
- Molecular Medicine ProgramUniversity of UtahSalt Lake CityUtahUSA
- The Department of Internal MedicineDivision of Nephrology and HypertensionUniversity of UtahSalt Lake CityUtahUSA
- The Department of Human GeneticsUniversity of UtahSalt Lake CityUtahUSA
- The Medical ServiceVeterans Affairs Salt Lake City Health Care SystemSalt Lake CityUtahUSA
| | - Alexander Staruschenko
- Department of Molecular Pharmacology and PhysiologyUniversity of South FloridaTampaFloridaUSA
- The James A. Haley Veterans HospitalTampaFloridaUSA
| | - Jennifer S. Pollock
- Department of MedicineDivision of NephrologySection of Cardio‐Renal Physiology and MedicineUniversity of Alabama at BirminghamBirminghamAlabamaUSA
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25
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Ohno Y, Kunisawa N, Shimizu S. Emerging Roles of Astrocyte Kir4.1 Channels in the Pathogenesis and Treatment of Brain Diseases. Int J Mol Sci 2021; 22:ijms221910236. [PMID: 34638578 PMCID: PMC8508600 DOI: 10.3390/ijms221910236] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 09/14/2021] [Accepted: 09/16/2021] [Indexed: 12/15/2022] Open
Abstract
Inwardly rectifying Kir4.1 channels in astrocytes mediate spatial potassium (K+) buffering, a clearance mechanism for excessive extracellular K+, in tripartite synapses. In addition to K+ homeostasis, astrocytic Kir4.1 channels also play an essential role in regulating extracellular glutamate levels via coupling with glutamate transporters. Moreover, Kir4.1 channels act as novel modulators of the expression of brain-derived neurotrophic factor (BDNF) in astrocytes. Specifically, inhibition of astrocytic Kir4.1 channels elevates extracellular K+ and glutamate levels at synapses and facilitates BDNF expression in astrocytes. These changes elevate neural excitability, which may facilitate synaptic plasticity and connectivity. In this article, we summarize the functions and pharmacological features of Kir4.1 channels in astrocytes and highlight the importance of these channels in the treatment of brain diseases. Although further validation in animal models and human patients is required, astrocytic Kir4.1 channel could potentially serve as a novel therapeutic target for the treatment of depressive disorders and epilepsy.
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26
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Xiao Y, Duan XP, Zhang DD, Wang WH, Lin DH. Deletion of renal Nedd4-2 abolishes the effect of high K + intake on Kir4.1/Kir5.1 and NCC activity in the distal convoluted tubule. Am J Physiol Renal Physiol 2021; 321:F1-F11. [PMID: 34029145 DOI: 10.1152/ajprenal.00072.2021] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
High-dietary K+ (HK) intake inhibits basolateral Kir4.1/Kir5.1 activity in the distal convoluted tubule (DCT), and HK-induced inhibition of Kir4.1/Kir5.1 is essential for HK-induced inhibition of NaCl cotransporter (NCC). Here, we examined whether neural precursor cell expressed developmentally downregulated 4-2 (Nedd4-2) deletion compromises the effect of HK on basolateral Kir4.1/Kir5.1 and NCC in the DCT. Single-channel recording and whole cell recording showed that neither HK decreased nor low-dietary K+ (LK) increased basolateral Kir4.1/Kir5.1 activity of the DCT in kidney tubule-specific Nedd4-2 knockout (Ks-Nedd4-2 KO) mice. In contrast, HK inhibited and LK increased Kir4.1/Kir5.1 activity in control mice [neural precursor cell expressed developmentally downregulated 4-like (Nedd4l)flox/flox]. Also, HK intake decreased the negativity of K+ current reversal potential in the DCT (depolarization) only in control mice but not in Ks-Nedd4-2 KO mice. Renal clearance experiments showed that HK intake decreased, whereas LK intake increased, hydrochlorothiazide-induced renal Na+ excretion only in control mice, but this effect was absent in Ks-Nedd4-2 KO mice. Western blot analysis also demonstrated that HK-induced inhibition of phosphorylated NCC (Thr53) and total NCC was observed only in control mice but not in Ks-Nedd4-2 KO mice. Furthermore, expression of all three subunits of the epithelial Na+ channel in Ks-Nedd4-2 KO mice on HK was higher than in control mice. Thus, plasma K+ concentrations were similar between Nedd4lflox/flox and Ks-Nedd4-2 KO mice on HK for 7 days despite high NCC expression. We conclude that Nedd4-2 plays a role in regulating HK-induced inhibition of Kir4.1/Kir5.1 and NCC in the DCT.NEW & NOTEWORTHY Basolateral Kir4.1/Kir5.1 in the distal convoluted tubule plays an important role as a "K+ sensor" in the regulation of renal K+ excretion after high K+ intake. We found that neural precursor cell expressed developmentally downregulated 4-2 (Nedd4-2) a role in mediating the effect of K+ diet on Kir4.1/Kir5.1 and NaCl cotransporter because high K+ intake failed to inhibit basolateral Kir4.1/Kir5.1 and NaCl cotransporter in kidney tubule-specific Nedd4-2 knockout mice.
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Affiliation(s)
- Yu Xiao
- Department of Physiology, Qiqihar Medical College, Heilongjiang, China.,Department of Pharmacology, New York Medical College, Valhalla, New York
| | - Xin-Peng Duan
- Department of Pharmacology, New York Medical College, Valhalla, New York
| | - Dan-Dan Zhang
- Department of Pharmacology, New York Medical College, Valhalla, New York
| | - Wen-Hui Wang
- Department of Pharmacology, New York Medical College, Valhalla, New York
| | - Dao-Hong Lin
- Department of Pharmacology, New York Medical College, Valhalla, New York
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27
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Duan XP, Wu P, Zhang DD, Gao ZX, Xiao Y, Ray EC, Wang WH, Lin DH. Deletion of Kir5.1 abolishes the effect of high Na + intake on Kir4.1 and Na +-Cl - cotransporter. Am J Physiol Renal Physiol 2021; 320:F1045-F1058. [PMID: 33900854 DOI: 10.1152/ajprenal.00004.2021] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
High sodium (HS) intake inhibited epithelial Na+ channel (ENaC) in the aldosterone-sensitive distal nephron and Na+-Cl- cotransporter (NCC) by suppressing basolateral Kir4.1/Kir5.1 in the distal convoluted tubule (DCT), thereby increasing renal Na+ excretion but not affecting K+ excretion. The aim of the present study was to explore whether deletion of Kir5.1 compromises the inhibitory effect of HS on NCC expression/activity and renal K+ excretion. Patch-clamp experiments demonstrated that HS failed to inhibit DCT basolateral K+ channels and did not depolarize K+ current reversal potential of the DCT in Kir5.1 knockout (KO) mice. Moreover, deletion of Kir5.1 not only increased the expression of Kir4.1, phospho-NCC, and total NCC but also abolished the inhibitory effect of HS on the expression of Kir4.1, phospho-NCC, and total NCC and thiazide-induced natriuresis. Also, low sodium-induced stimulation of NCC expression/activity and basolateral K+ channels in the DCT were absent in Kir5.1 KO mice. Deletion of Kir5.1 decreased ENaC currents in the late DCT, and HS further inhibited ENaC activity in Kir5.1 KO mice. Finally, measurement of the basal renal K+ excretion rate with the modified renal clearance method demonstrated that long-term HS inhibited the renal K+ excretion rate and steadily increased plasma K+ levels in Kir5.1 KO mice but not in wild-type mice. We conclude that Kir5.1 plays an important role in mediating the effect of HS intake on basolateral K+ channels in the DCT and NCC activity/expression. Kir5.1 is involved in maintaining renal ability of K+ excretion during HS intake. NEW & NOTEWORTHY Kir5.1 plays an important role in mediating the effect of high sodium intake on basolateral K+ channels in the distal convoluted tubule and Na+-Cl- cotransporter activity/expression.
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Affiliation(s)
- Xin-Peng Duan
- Department of Pharmacology, New York Medical College, Valhalla, New York.,Department of Histology and Embryology, Xuzhou Medical University, Xuzhou, People's Republic of China
| | - Peng Wu
- Department of Pharmacology, New York Medical College, Valhalla, New York.,Institute of Hypertension and Kidney Disease, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, People's Republic of China
| | - Dan-Dan Zhang
- Department of Pharmacology, New York Medical College, Valhalla, New York.,Guangdong-Hong Kong Joint Laboratory on Immunological and Genetic Kidney Diseases, Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, People's Republic of China
| | - Zhong-Xiuzi Gao
- Department of Pharmacology, New York Medical College, Valhalla, New York.,Institute of Hypertension and Kidney Disease, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, People's Republic of China
| | - Yu Xiao
- Department of Pharmacology, New York Medical College, Valhalla, New York.,Department of Physiology, Qiqihar Medical University, Qiqihar, People's Republic of China
| | - Evan C Ray
- Renal-Electrolyte Division, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Wen-Hui Wang
- Department of Pharmacology, New York Medical College, Valhalla, New York
| | - Dao-Hong Lin
- Department of Pharmacology, New York Medical College, Valhalla, New York
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28
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Zhang DD, Duan XP, Xiao Y, Wu P, Gao ZX, Wang WH, Lin DH. Deletion of renal Nedd4-2 abolishes the effect of high sodium intake (HS) on Kir4.1, ENaC, and NCC and causes hypokalemia during high HS. Am J Physiol Renal Physiol 2021; 320:F883-F896. [PMID: 33818128 DOI: 10.1152/ajprenal.00555.2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Neural precursor cell expressed developmentally downregulated protein 4-2 (Nedd4-2) regulates the expression of Kir4.1, thiazide-sensitive NaCl cotransporter (NCC), and epithelial Na+ channel (ENaC) in the aldosterone-sensitive distal nephron (ASDN), and Nedd4-2 deletion causes salt-sensitive hypertension. We now examined whether Nedd4-2 deletion compromises the effect of high-salt (HS) diet on Kir4.1, NCC, ENaC, and renal K+ excretion. Immunoblot analysis showed that HS diet decreased the expression of Kir4.1, Ca2+-activated large-conductance K+ channel subunit-α (BKα), ENaCβ, ENaCγ, total NCC, and phospho-NCC (at Thr53) in floxed neural precursor cell expressed developmentally downregulated gene 4-like (Nedd4lfl/fl) mice, whereas these effects were absent in kidney-specific Nedd4-2 knockout (Ks-Nedd4-2 KO) mice. Renal clearance experiments also demonstrated that Nedd4-2 deletion abolished the inhibitory effect of HS diet on hydrochlorothiazide-induced natriuresis. Patch-clamp experiments showed that neither HS diet nor low-salt diet had an effect on Kir4.1/Kir5.1 currents of the distal convoluted tubule in Nedd4-2-deficient mice, whereas we confirmed that HS diet inhibited and low-salt diet increased Kir4.1/Kir5.1 activity in Nedd4lflox/flox mice. Nedd4-2 deletion increased ENaC currents in the ASDN, and this increase was more robust in the cortical collecting duct than in the distal convoluted tubule. Also, HS-induced inhibition of ENaC currents in the ASDN was absent in Nedd4-2-deficient mice. Renal clearance experiments showed that HS intake for 2 wk increased the basal level of renal K+ excretion and caused hypokalemia in Ks-Nedd4-2-KO mice but not in Nedd4lflox/flox mice. In contrast, plasma Na+ concentrations were similar in Nedd4lflox/flox and Ks-Nedd4-2 KO mice on HS diet. We conclude that Nedd4-2 plays an important role in mediating the inhibitory effect of HS diet on Kir4.1, ENaC, and NCC and is essential for maintaining normal renal K+ excretion and plasma K+ ranges during long-term HS diet.NEW & NOTEWORTHY The present study suggests that Nedd4-2 is involved in mediating the inhibitory effect of high salt (HS) diet on Kir4.1/kir5.1 in the distal convoluted tubule, NaCl cotransporter function, and epithelial Na+ channel activity and that Nedd4-2 plays an essential role in maintaining K+ homeostasis in response to a long-term HS diet. This suggests the possibility that HS intake could lead to hypokalemia in subjects lacking proper Nedd4-2 E3 ubiquitin ligase activity in aldosterone-sensitive distal nephron.
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Affiliation(s)
- Dan-Dan Zhang
- Guangdong-Hong Kong Joint Laboratory on Immunological and Genetic Kidney Diseases, Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China.,Department of Pharmacology, New York Medical College, Valhalla, New York
| | - Xin-Peng Duan
- Department of Pharmacology, New York Medical College, Valhalla, New York
| | - Yu Xiao
- Department of Physiology, Qiqihar Medical College, Heilongjiang, China.,Department of Pharmacology, New York Medical College, Valhalla, New York
| | - Peng Wu
- Department of Pharmacology, New York Medical College, Valhalla, New York
| | - Zhong-Xiuzi Gao
- Department of Pharmacology, New York Medical College, Valhalla, New York
| | - Wen-Hui Wang
- Department of Pharmacology, New York Medical College, Valhalla, New York
| | - Dao-Hong Lin
- Department of Pharmacology, New York Medical College, Valhalla, New York
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29
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Gagnon KB, Delpire E. Sodium Transporters in Human Health and Disease. Front Physiol 2021; 11:588664. [PMID: 33716756 PMCID: PMC7947867 DOI: 10.3389/fphys.2020.588664] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 10/06/2020] [Indexed: 12/12/2022] Open
Abstract
Sodium (Na+) electrochemical gradients established by Na+/K+ ATPase activity drives the transport of ions, minerals, and sugars in both excitable and non-excitable cells. Na+-dependent transporters can move these solutes in the same direction (cotransport) or in opposite directions (exchanger) across both the apical and basolateral plasma membranes of polarized epithelia. In addition to maintaining physiological homeostasis of these solutes, increases and decreases in sodium may also initiate, directly or indirectly, signaling cascades that regulate a variety of intracellular post-translational events. In this review, we will describe how the Na+/K+ ATPase maintains a Na+ gradient utilized by multiple sodium-dependent transport mechanisms to regulate glucose uptake, excitatory neurotransmitters, calcium signaling, acid-base balance, salt-wasting disorders, fluid volume, and magnesium transport. We will discuss how several Na+-dependent cotransporters and Na+-dependent exchangers have significant roles in human health and disease. Finally, we will discuss how each of these Na+-dependent transport mechanisms have either been shown or have the potential to use Na+ in a secondary role as a signaling molecule.
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Affiliation(s)
- Kenneth B. Gagnon
- Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, United States
| | - Eric Delpire
- Department of Anesthesiology, School of Medicine, Vanderbilt University, Nashville, TN, United States
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30
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Manis AD, Palygin O, Isaeva E, Levchenko V, LaViolette PS, Pavlov TS, Hodges MR, Staruschenko A. Kcnj16 knockout produces audiogenic seizures in the Dahl salt-sensitive rat. JCI Insight 2021; 6:143251. [PMID: 33232300 PMCID: PMC7821607 DOI: 10.1172/jci.insight.143251] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 11/19/2020] [Indexed: 01/08/2023] Open
Abstract
Kir5.1 is an inwardly rectifying potassium (Kir) channel subunit abundantly expressed in the kidney and brain. We previously established the physiologic consequences of a Kcnj16 (gene encoding Kir5.1) knockout in the Dahl salt-sensitive rat (SSKcnj16-/-), which caused electrolyte/pH dysregulation and high-salt diet-induced mortality. Since Kir channel gene mutations may alter neuronal excitability and are linked to human seizure disorders, we hypothesized that SSKcnj16-/- rats would exhibit neurological phenotypes, including increased susceptibility to seizures. SSKcnj16-/- rats exhibited increased light sensitivity (fMRI) and reproducible sound-induced tonic-clonic audiogenic seizures confirmed by electroencephalography. Repeated seizure induction altered behavior, exacerbated hypokalemia, and led to approximately 38% mortality in male SSKcnj16-/- rats. Dietary potassium supplementation did not prevent audiogenic seizures but mitigated hypokalemia and prevented mortality induced by repeated seizures. These results reveal a distinct, nonredundant role for Kir5.1 channels in the brain, introduce a rat model of audiogenic seizures, and suggest that yet-to-be identified mutations in Kcnj16 may cause or contribute to seizure disorders.
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MESH Headings
- Acoustic Stimulation/adverse effects
- Animals
- Disease Models, Animal
- Electroencephalography
- Epilepsy, Reflex/etiology
- Epilepsy, Reflex/genetics
- Epilepsy, Reflex/physiopathology
- Female
- Gene Knockout Techniques
- Humans
- Hypokalemia/etiology
- Hypokalemia/genetics
- Male
- Mutation
- Potassium Channels, Inwardly Rectifying/deficiency
- Potassium Channels, Inwardly Rectifying/genetics
- Potassium Channels, Inwardly Rectifying/physiology
- Potassium, Dietary/administration & dosage
- Rats
- Rats, Inbred Dahl
- Rats, Transgenic
- Seizures/etiology
- Seizures/genetics
- Seizures/physiopathology
- Severity of Illness Index
- Kir5.1 Channel
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Affiliation(s)
| | - Oleg Palygin
- Department of Physiology
- Cardiovascular Center, and
| | | | | | - Peter S. LaViolette
- Department of Radiology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | | | | | - Alexander Staruschenko
- Department of Physiology
- Cardiovascular Center, and
- Clement J. Zablocki VA Medical Center, Milwaukee, Wisconsin, USA
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31
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Maeoka Y, McCormick JA. NaCl cotransporter activity and Mg 2+ handling by the distal convoluted tubule. Am J Physiol Renal Physiol 2020; 319:F1043-F1053. [PMID: 33135481 DOI: 10.1152/ajprenal.00463.2020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The genetic disease Gitelman syndrome, knockout mice, and pharmacological blockade with thiazide diuretics have revealed that reduced activity of the NaCl cotransporter (NCC) promotes renal Mg2+ wasting. NCC is expressed along the distal convoluted tubule (DCT), and its activity determines Mg2+ entry into DCT cells through transient receptor potential channel subfamily M member 6 (TRPM6). Several other genetic forms of hypomagnesemia lower the drive for Mg2+ entry by inhibiting activity of basolateral Na+-K+-ATPase, and reduced NCC activity may do the same. Lower intracellular Mg2+ may promote further Mg2+ loss by directly decreasing activity of Na+-K+-ATPase. Lower intracellular Mg2+ may also lower Na+-K+-ATPase indirectly by downregulating NCC. Lower NCC activity also induces atrophy of DCT cells, decreasing the available number of TRPM6 channels. Conversely, a mouse model with increased NCC activity was recently shown to display normal Mg2+ handling. Moreover, recent studies have identified calcineurin and uromodulin (UMOD) as regulators of both NCC and Mg2+ handling by the DCT. Calcineurin inhibitors paradoxically cause hypomagnesemia in a state of NCC activation, but this may be related to direct effects on TRPM6 gene expression. In Umod-/- mice, the cause of hypomagnesemia may be partly due to both decreased NCC expression and lower TRPM6 expression on the cell surface. This mini-review discusses these new findings and the possible role of altered Na+ flux through NCC and ultimately Na+-K+-ATPase in Mg2+ reabsorption by the DCT.
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Affiliation(s)
- Yujiro Maeoka
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon
| | - James A McCormick
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon
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32
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McFarlin BE, Chen Y, Priver TS, Ralph DL, Mercado A, Gamba G, Madhur MS, McDonough AA. Coordinate adaptations of skeletal muscle and kidney to maintain extracellular [K +] during K +-deficient diet. Am J Physiol Cell Physiol 2020; 319:C757-C770. [PMID: 32845718 PMCID: PMC7654654 DOI: 10.1152/ajpcell.00362.2020] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 08/17/2020] [Accepted: 08/19/2020] [Indexed: 12/16/2022]
Abstract
Extracellular fluid (ECF) potassium concentration ([K+]) is maintained by adaptations of kidney and skeletal muscle, responses heretofore studied separately. We aimed to determine how these organ systems work in concert to preserve ECF [K+] in male C57BL/6J mice fed a K+-deficient diet (0K) versus 1% K+ diet (1K) for 10 days (n = 5-6/group). During 0K feeding, plasma [K+] fell from 4.5 to 2 mM; hindlimb muscle (gastrocnemius and soleus) lost 28 mM K+ (from 115 ± 2 to 87 ± 2 mM) and gained 27 mM Na+ (from 27 ± 0.4 to 54 ± 2 mM). Doubling of muscle tissue [Na+] was not associated with inflammation, cytokine production or hypertension as reported by others. Muscle transporter adaptations in 0K- versus 1K-fed mice, assessed by immunoblot, included decreased sodium pump α2-β2 subunits, decreased K+-Cl- cotransporter isoform 3, and increased phosphorylated (p) Na+,K+,2Cl- cotransporter isoform 1 (NKCC1p), Ste20/SPS-1-related proline-alanine rich kinase (SPAKp), and oxidative stress-responsive kinase 1 (OSR1p) consistent with intracellular fluid (ICF) K+ loss and Na+ gain. Renal transporters' adaptations, effecting a 98% reduction in K+ excretion, included two- to threefold increased phosphorylated Na+-Cl- cotransporter (NCCp), SPAKp, and OSR1p abundance, limiting Na+ delivery to epithelial Na+ channels where Na+ reabsorption drives K+ secretion; and renal K sensor Kir 4.1 abundance fell 25%. Mass balance estimations indicate that over 10 days of 0K feeding, mice lose ~48 μmol K+ into the urine and muscle shifts ~47 μmol K+ from ICF to ECF, illustrating the importance of the concerted responses during K+ deficiency.
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Affiliation(s)
- Brandon E McFarlin
- Department of Physiology and Neuroscience, Keck School of Medicine of the University of Southern California, Los Angeles, California
| | - Yuhan Chen
- Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee
- Department of Cardiology, Nanjing University Medical School, Nanjing, China
| | - Taylor S Priver
- Department of Physiology and Neuroscience, Keck School of Medicine of the University of Southern California, Los Angeles, California
| | - Donna L Ralph
- Department of Physiology and Neuroscience, Keck School of Medicine of the University of Southern California, Los Angeles, California
| | - Adriana Mercado
- Department of Nephrology, Instituto Nacional de Cardiología Ignacio Chávez, Mexico City, Mexico
| | - Gerardo Gamba
- Molecular Physiology Unit, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México and Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - Meena S Madhur
- Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Alicia A McDonough
- Department of Physiology and Neuroscience, Keck School of Medicine of the University of Southern California, Los Angeles, California
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33
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Wei KY, Gritter M, Vogt L, de Borst MH, Rotmans JI, Hoorn EJ. Dietary potassium and the kidney: lifesaving physiology. Clin Kidney J 2020; 13:952-968. [PMID: 33391739 PMCID: PMC7769543 DOI: 10.1093/ckj/sfaa157] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Indexed: 02/07/2023] Open
Abstract
Potassium often has a negative connotation in Nephrology as patients with chronic kidney disease (CKD) are prone to develop hyperkalaemia. Approaches to the management of chronic hyperkalaemia include a low potassium diet or potassium binders. Yet, emerging data indicate that dietary potassium may be beneficial for patients with CKD. Epidemiological studies have shown that a higher urinary potassium excretion (as proxy for higher dietary potassium intake) is associated with lower blood pressure (BP) and lower cardiovascular risk, as well as better kidney outcomes. Considering that the composition of our current diet is characterized by a high sodium and low potassium content, increasing dietary potassium may be equally important as reducing sodium. Recent studies have revealed that dietary potassium modulates the activity of the thiazide-sensitive sodium-chloride cotransporter in the distal convoluted tubule (DCT). The DCT acts as a potassium sensor to control the delivery of sodium to the collecting duct, the potassium-secreting portion of the kidney. Physiologically, this allows immediate kaliuresis after a potassium load, and conservation of potassium during potassium deficiency. Clinically, it provides a novel explanation for the inverse relationship between dietary potassium and BP. Moreover, increasing dietary potassium intake can exert BP-independent effects on the kidney by relieving the deleterious effects of a low potassium diet (inflammation, oxidative stress and fibrosis). The aim of this comprehensive review is to link physiology with clinical medicine by proposing that the same mechanisms that allow us to excrete an acute potassium load also protect us from hypertension, cardiovascular disease and CKD.
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Affiliation(s)
- Kuang-Yu Wei
- Department of Internal Medicine, Division of Nephrology and Transplantation, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands.,Department of Internal Medicine, Division of Nephrology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Martin Gritter
- Department of Internal Medicine, Division of Nephrology and Transplantation, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Liffert Vogt
- Department of Internal Medicine, Division of Nephrology, Amsterdam University Medical Center, Amsterdam, The Netherlands
| | - Martin H de Borst
- Department of Internal Medicine, Division of Nephrology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Joris I Rotmans
- Department of Internal Medicine, Division of Nephrology, Leiden University Medical Center, Leiden, The Netherlands
| | - Ewout J Hoorn
- Department of Internal Medicine, Division of Nephrology and Transplantation, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
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34
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Imenez Silva PH, Wagner CA. Potassium channels in control of renal function. Kidney Int 2020; 97:253-255. [PMID: 31980072 DOI: 10.1016/j.kint.2019.10.029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 10/22/2019] [Accepted: 10/24/2019] [Indexed: 11/18/2022]
Abstract
Potassium channels are important to control membrane potential and drive epithelial transport processes. In this issue of Kidney International, Bignon et al. report the role of the Kir4.2 K+-channel, localized at the basolateral membrane of proximal tubules, in the reabsorption of bicarbonate and the modulation of renal ammoniagenesis. The findings have implications for our understanding of how the kidney reacts to hypokalemia, an acid load, and the metabolic acidosis of patients with advanced stages of chronic kidney disease.
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Affiliation(s)
- Pedro H Imenez Silva
- Institute of Physiology, University of Zurich, Zurich, Switzerland; National Center of Competence in Research NCCR Kidney.CH, Switzerland
| | - Carsten A Wagner
- Institute of Physiology, University of Zurich, Zurich, Switzerland; National Center of Competence in Research NCCR Kidney.CH, Switzerland.
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35
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Vio CP, Gallardo P, Cespedes C, Salas D, Diaz-Elizondo J, Mendez N. Dietary Potassium Downregulates Angiotensin-I Converting Enzyme, Renin, and Angiotensin Converting Enzyme 2. Front Pharmacol 2020; 11:920. [PMID: 32625100 PMCID: PMC7314933 DOI: 10.3389/fphar.2020.00920] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2019] [Accepted: 06/05/2020] [Indexed: 12/16/2022] Open
Abstract
Background The importance of dietary potassium in health and disease has been underestimated compared with that placed on dietary sodium. Larger effort has been made on reduction of sodium intake and less on the adequate dietary potassium intake, although natural food contains much more potassium than sodium. The benefits of a potassium-rich diet are known, however, the mechanism by which it exerts its preventive action, remains to be elucidated. With the hypothesis that dietary potassium reduces renal vasoconstrictor components of the renin-angiotensin system in the long-term, we studied the effect of high potassium diet on angiotensin-I converting enzyme, renin, and angiotensin converting enzyme 2. Methods Sprague Dawley male rats on a normal sodium diet received normal potassium (0.9%, NK) or high potassium diet (3%, HK) for 4 weeks. Urine was collected in metabolic cages for electrolytes and urinary volume measurement. Renal tissue was used to analyze angiotensin-I converting enzyme, renin, and angiotensin converting enzyme 2 expression. Protein abundance analysis was done by Western blot; gene expression by mRNA levels by RT-qPCR. Renal distribution of angiotensin-I converting enzyme and renin was done by immunohistochemistry and morphometric analysis in coded samples. Results High potassium diet (4 weeks) reduced the levels of renin, angiotensin-I converting enzyme, and angiotensin converting enzyme 2. Angiotensin-I converting enzyme was located in the brush border of proximal tubules and with HK diet decreased the immunostaining intensity (P < 0.05), decreased the mRNA (P < 0.01) and the protein levels (P < 0.01). Renin localization was restricted to granular cells of the afferent arteriole and HK diet decreased the number of renin positive cells (P < 0.01) and renin mRNA levels (P < 0.01). High potassium intake decreased angiotensin converting enzyme 2 gene expression and protein levels (P < 0.01).No morphological abnormalities were observed in renal tissue during high potassium diet.The reduced expression of angiotensin-I converting enzyme, renin, and angiotensin converting enzyme 2 during potassium supplementation suggest that high dietary potassium intake could modulate these vasoactive enzymes and this effects can contribute to the preventive and antihypertensive effect of potassium.
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Affiliation(s)
- Carlos P Vio
- Center for Aging and Regeneration CARE UC, Department of Physiology, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.,Facultad de Medicina y Ciencia, Universidad San Sebastian, Santiago, Chile
| | - Pedro Gallardo
- Facultad de Medicina, Escuela de Medicina, Universidad Finis Terrae, Santiago, Chile
| | - Carlos Cespedes
- Center for Aging and Regeneration CARE UC, Department of Physiology, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.,Facultad de Medicina y Ciencia, Universidad San Sebastian, Santiago, Chile
| | - Daniela Salas
- Center for Aging and Regeneration CARE UC, Department of Physiology, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Jessica Diaz-Elizondo
- Center for Aging and Regeneration CARE UC, Department of Physiology, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Natalia Mendez
- Facultad de Medicina, Institute of Anatomy, Histology and Pathology, Universidad Austral de Chile, Valdivia, Chile
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Wang MX, Wang LJ, Xiao Y, Zhang DD, Duan XP, Wang WH. Epoxyeicosatrienoic acid metabolites inhibit Kir4.1/Kir5.1 in the distal convoluted tubule. Am J Physiol Renal Physiol 2020; 318:F1369-F1376. [PMID: 32308018 PMCID: PMC7311705 DOI: 10.1152/ajprenal.00018.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 03/12/2020] [Accepted: 04/13/2020] [Indexed: 11/22/2022] Open
Abstract
Cytochrome P-450 (Cyp) epoxygenase-dependent metabolites of arachidonic acid (AA) have been shown to inhibit renal Na+ transport, and inhibition of Cyp-epoxygenase is associated with salt-sensitive hypertension. We used the patch-clamp technique to examine whether Cyp-epoxygenase-dependent AA metabolites inhibited the basolateral 40-pS K+ channel (Kir4.1/Kir5.1) in the distal convoluted tubule (DCT). Application of AA inhibited the basolateral 40-pS K+ channel in the DCT. The inhibitory effect of AA on the 40-pS K+ channel was specific because neither linoleic nor oleic acid was able to mimic the effect of AA on the K+ channel. Inhibition of Cyp-monooxygenase with N-methylsulfonyl-12,12-dibromododec-11-enamide or inhibition of cyclooxygenase with indomethacin failed to abolish the inhibitory effect of AA on the 40-pS K+ channel. However, the inhibition of Cyp-epoxygenase with N-methylsulfonyl-6-(propargyloxyphenyl)hexanamide abolished the effect of AA on the 40-pS K+ channel in the DCT. Moreover, addition of either 11,12-epoxyeicosatrienoic acid (EET) or 14,15-EET also inhibited the 40-pS K+ channel in the DCT. Whole cell recording demonstrated that application of AA decreased, whereas N-methylsulfonyl-6-(propargyloxyphenyl)hexanamide treatment increased, Ba2+-sensitive K+ currents in the DCT. Finally, application of 14,15-EET but not AA was able to inhibit the basolateral 40-pS K+ channel in the DCT of Cyp2c44-/- mice. We conclude that Cyp-epoxygenase-dependent AA metabolites inhibit the basolateral Kir4.1/Kir5.1 in the DCT and that Cyp2c44-epoxygenase plays a role in the regulation of the basolateral K+ channel in the mouse DCT.
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MESH Headings
- 8,11,14-Eicosatrienoic Acid/analogs & derivatives
- 8,11,14-Eicosatrienoic Acid/metabolism
- 8,11,14-Eicosatrienoic Acid/pharmacology
- Amides/pharmacology
- Animals
- Arachidonic Acid/metabolism
- Arachidonic Acid/pharmacology
- Cytochrome P450 Family 2/antagonists & inhibitors
- Cytochrome P450 Family 2/genetics
- Cytochrome P450 Family 2/metabolism
- Enzyme Inhibitors/pharmacology
- Kidney Tubules, Distal/drug effects
- Kidney Tubules, Distal/metabolism
- Male
- Membrane Potentials
- Mice, 129 Strain
- Mice, Knockout
- Potassium Channel Blockers/metabolism
- Potassium Channel Blockers/pharmacology
- Potassium Channels, Inwardly Rectifying/antagonists & inhibitors
- Potassium Channels, Inwardly Rectifying/metabolism
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Affiliation(s)
- Ming-Xiao Wang
- Department of Physiology, Zhuhai Campus of Zunyi Medical University, Zunyi, Guizhou, China
| | - Li-Jun Wang
- Department of Physiology, Harbin Medical University, Harbin, China
| | - Yu Xiao
- Department of Physiology, Qiqihar Medical College, Heilongjiang, China
| | - Dan-Dan Zhang
- Department of Pharmacology, New York Medical College, Valhalla, New York
| | - Xin-Peng Duan
- Department of Pharmacology, New York Medical College, Valhalla, New York
| | - Wen-Hui Wang
- Department of Pharmacology, New York Medical College, Valhalla, New York
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Veiras LC, McFarlin BE, Ralph DL, Buncha V, Prescott J, Shirvani BS, McDonough JC, Ha D, Giani J, Gurley SB, Mamenko M, McDonough AA. Electrolyte and transporter responses to angiotensin II induced hypertension in female and male rats and mice. Acta Physiol (Oxf) 2020; 229:e13448. [PMID: 31994810 DOI: 10.1111/apha.13448] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 01/21/2020] [Accepted: 01/23/2020] [Indexed: 12/15/2022]
Abstract
AIM Sexual dimorphisms are evident along the nephron: Females (F) exhibit higher ratios of renal distal to proximal Na+ transporters' abundance, greater lithium clearance (CLi ) more rapid natriuresis in response to saline infusion and lower plasma [K+ ] vs. males (M). During angiotensin II infusion hypertension (AngII-HTN) M exhibit distal Na+ transporter activation, lower proximal and medullary loop transporters, blunted natriuresis in response to saline load, and reduced plasma [K+ ]. This study aimed to determine whether responses of F to AngII-HTN mimicked those in M or were impacted by sexual dimorphisms evident at baseline. METHODS Sprague Dawley rats and C57BL/6 mice were AngII infused via osmotic minipumps 2 and 3 weeks, respectively, and assessed by metabolic cage collections, tail-cuff sphygmomanometer, semi-quantitative immunoblotting of kidney and patch-clamp electrophysiology. RESULTS In F rats, AngII-infusion increased BP to 190 mm Hg, increased phosphorylation of cortical NKCC2, NCC and cleavage of ENaC two to threefold, increased ENaC channel activity threefold and aldosterone 10-fold. K+ excretion increased and plasma [K+ ] decreased. Evidence of natriuresis in F included increased urine Na+ excretion and CLi , and decreased medullary NHE3, NKCC2 and Na,K-ATPase abundance. In C57BL/6 mice, AngII-HTN increased abundance of distal Na+ transporters, suppressed proximal-medullary transporters and reduced plasma [K+ ] in both F and M. CONCLUSION Despite baseline sexual dimorphisms, AngII-HTN provokes similar increases in BP, aldosterone, distal transporters, ENaC channel activation and K+ loss accompanied by similar suppression of proximal and loop Na+ transporters, natriuresis and diuresis in females and males.
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Affiliation(s)
- Luciana C. Veiras
- Department of Physiology and Neuroscience Keck School of Medicine of USC Los Angeles CA USA
- Department of Biomedical Sciences Cedars‐Sinai Medical Center Los Angeles CA USA
| | - Brandon E. McFarlin
- Department of Physiology and Neuroscience Keck School of Medicine of USC Los Angeles CA USA
| | - Donna L. Ralph
- Department of Physiology and Neuroscience Keck School of Medicine of USC Los Angeles CA USA
| | - Vadym Buncha
- Department of Physiology Medical College of Georgia at Augusta University Augusta GA USA
| | - Jessica Prescott
- Department of Physiology and Neuroscience Keck School of Medicine of USC Los Angeles CA USA
| | - Borna S. Shirvani
- Department of Physiology and Neuroscience Keck School of Medicine of USC Los Angeles CA USA
| | - Jillian C. McDonough
- Department of Physiology and Neuroscience Keck School of Medicine of USC Los Angeles CA USA
| | - Darren Ha
- Department of Physiology and Neuroscience Keck School of Medicine of USC Los Angeles CA USA
| | - Jorge Giani
- Department of Biomedical Sciences Cedars‐Sinai Medical Center Los Angeles CA USA
| | - Susan B. Gurley
- Division of Nephrology and Hypertension Oregon Health and Science University Portland OR USA
| | - Mykola Mamenko
- Department of Physiology Medical College of Georgia at Augusta University Augusta GA USA
| | - Alicia A. McDonough
- Department of Physiology and Neuroscience Keck School of Medicine of USC Los Angeles CA USA
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Zhang J, Han J, Li L, Zhang Q, Feng Y, Jiang Y, Deng F, Zhang Y, Wu Q, Chen B, Hu J. Inwardly rectifying potassium channel 5.1: Structure, function, and possible roles in diseases. Genes Dis 2020; 8:272-278. [PMID: 33997174 PMCID: PMC8093645 DOI: 10.1016/j.gendis.2020.03.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 03/02/2020] [Accepted: 03/13/2020] [Indexed: 11/30/2022] Open
Abstract
Inwardly rectifying potassium (Kir) channels make it easier for K+ to enter into a cell and subsequently regulate cellular biological functions. Kir5.1 (encoded by KCNJ16) alone can form a homotetramer and can form heterotetramers with Kir4.1 (encoded by KCNJ10) or Kir4.2 (encoded by KCNJ15). In most cases, homomeric Kir5.1 is non-functional, while heteromeric Kir5.1 on the cell membrane contributes to the inward flow of K+ ions, which can be regulated by intracellular pH and a variety of signaling mechanisms. In the form of a heterotetramer, Kir5.1 regulates Kir4.1/4.2 activity and is involved in the maintenance of nephron function. Actually, homomeric Kir5.1 may also play a very important role in diseases, including in the ventilatory response to hypoxia and hypercapnia, hearing impairment, cardiovascular disease and cancer. With an increase in the number of studies into the roles of Kir channels, researchers are paying more attention to the pathophysiological functions of Kir5.1. This minireview provides an overview regarding these Kir5.1 roles.
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Affiliation(s)
- Junhui Zhang
- Institute of Burn Research, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, 400038, PR China.,State Key Laboratory of Trauma, Burns and Combined Injury, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, 400038, PR China.,Department of Endocrinology, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, 400038, PR China
| | - Jian Han
- Department of Obstetrics and Gynecology, Daping Hospital, Third Military Medical University (Army Medical University), Chongqing, 400042, PR China
| | - Lingfei Li
- Department of Dermatology, Daping Hospital, Third Military Medical University (Army Medical University), Chongqing, 400042, PR China
| | - Qiong Zhang
- Institute of Burn Research, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, 400038, PR China.,State Key Laboratory of Trauma, Burns and Combined Injury, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, 400038, PR China
| | - Yanhai Feng
- Institute of Burn Research, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, 400038, PR China.,State Key Laboratory of Trauma, Burns and Combined Injury, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, 400038, PR China
| | - Youzhao Jiang
- Department of Endocrinology, People's Hospital of Banan District, Chongqing, 401320, PR China
| | - Fang Deng
- Department of Endocrinology, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, 400038, PR China
| | - Yuping Zhang
- Department of Endocrinology, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, 400038, PR China
| | - Qinan Wu
- Department of Endocrinology, Chongqing Cancer Hospital (Chongqing University Cancer Hospital), Chongqing, 40030, PR China
| | - Bing Chen
- Department of Endocrinology, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, 400038, PR China
| | - Jiongyu Hu
- Institute of Burn Research, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, 400038, PR China.,State Key Laboratory of Trauma, Burns and Combined Injury, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, 400038, PR China.,Department of Endocrinology, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, 400038, PR China
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39
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Manis AD, Hodges MR, Staruschenko A, Palygin O. Expression, localization, and functional properties of inwardly rectifying K + channels in the kidney. Am J Physiol Renal Physiol 2020; 318:F332-F337. [PMID: 31841387 PMCID: PMC7052651 DOI: 10.1152/ajprenal.00523.2019] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 12/10/2019] [Accepted: 12/10/2019] [Indexed: 12/13/2022] Open
Abstract
Inwardly rectifying K+ (Kir) channels are expressed in multiple organs and cell types and play critical roles in cellular function. Most notably, Kir channels are major determinants of the resting membrane potential and K+ homeostasis. The renal outer medullary K+ channel (Kir1.1) was the first renal Kir channel identified and cloned in the kidney over two decades ago. Since then, several additional members, including classical and ATP-regulated Kir family classes, have been identified to be expressed in the kidney and to contribute to renal ion transport. Although the ATP-regulated Kir channel class remains the most well known due to severe pathological phenotypes associated with their mutations, progress is being made in defining the properties, localization, and physiological functions of other renal Kir channels, including those localized to the basolateral epithelium. This review is primarily focused on the current knowledge of the expression and localization of renal Kir channels but will also briefly describe their proposed functions in the kidney.
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Affiliation(s)
- Anna D Manis
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Matthew R Hodges
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
- Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Alexander Staruschenko
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin
- Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin
| | - Oleg Palygin
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin
- Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin
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40
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Recent insights into sodium and potassium handling by the aldosterone-sensitive distal nephron: a review of the relevant physiology. J Nephrol 2020; 33:431-445. [DOI: 10.1007/s40620-019-00684-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2019] [Accepted: 12/02/2019] [Indexed: 02/07/2023]
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41
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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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