1
|
Gritter M, Wei KY, Wouda RD, Musterd-Bhaggoe UM, Dijkstra KL, Kers J, Ramakers C, Vogt L, de Borst MH, Danser AHJ, Hoorn EJ, Rotmans JI. Chronic kidney disease increases the susceptibility to negative effects of low and high potassium intake. Nephrol Dial Transplant 2024; 39:795-807. [PMID: 37813819 PMCID: PMC11045281 DOI: 10.1093/ndt/gfad220] [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: 07/09/2023] [Indexed: 10/11/2023] Open
Abstract
BACKGROUND Dietary potassium (K+) has emerged as a modifiable factor for cardiovascular and kidney health in the general population, but its role in people with chronic kidney disease (CKD) is unclear. Here, we hypothesize that CKD increases the susceptibility to the negative effects of low and high K+ diets. METHODS We compared the effects of low, normal and high KChloride (KCl) diets and a high KCitrate diet for 4 weeks in male rats with normal kidney function and in male rats with CKD using the 5/6th nephrectomy model (5/6Nx). RESULTS Compared with rats with normal kidney function, 5/6Nx rats on the low KCl diet developed more severe extracellular and intracellular K+ depletion and more severe kidney injury, characterized by nephromegaly, infiltration of T cells and macrophages, decreased estimated glomerular filtration rate and increased albuminuria. The high KCl diet caused hyperkalemia, hyperaldosteronism, hyperchloremic metabolic acidosis and severe hypertension in 5/6Nx but not in sham rats. The high KCitrate diet caused hypochloremic metabolic alkalosis but attenuated hypertension despite higher abundance of the phosphorylated sodium chloride cotransporter (pNCC) and similar levels of plasma aldosterone and epithelial sodium channel abundance. All 5/6Nx groups had more collagen deposition than the sham groups and this effect was most pronounced in the high KCitrate group. Plasma aldosterone correlated strongly with kidney collagen deposition. CONCLUSIONS CKD increases the susceptibility to negative effects of low and high K+ diets in male rats, although the injury patterns are different. The low K+ diet caused inflammation, nephromegaly and kidney function decline, whereas the high K+ diet caused hypertension, hyperaldosteronism and kidney fibrosis. High KCitrate attenuated the hypertensive but not the pro-fibrotic effect of high KCl, which may be attributable to K+-induced aldosterone secretion. Our data suggest that especially in people with CKD it is important to identify the optimal threshold of dietary K+ intake.
Collapse
Affiliation(s)
- Martin Gritter
- Department of Internel Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Internal Medicine, Leiden University Medical Center, Leiden, The Netherlands
| | - Kuang-Yu Wei
- Department of Internel Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Internal Medicine, Division of Nephrology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Rosa D Wouda
- Department of Internal Medicine, Section of Nephrology, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Usha M Musterd-Bhaggoe
- Department of Internel Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Kyra L Dijkstra
- Pathology, Leiden University Medical Center, Leiden, The Netherlands
| | - Jesper Kers
- Pathology, Leiden University Medical Center, Leiden, The Netherlands
- Pathology, Amsterdam University Medical Center, Amsterdam, The Netherlands
- Van ‘t Hoff Institute for Molecular Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | | | - Liffert Vogt
- Department of Internal Medicine, Section of Nephrology, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Martin H de Borst
- Division of Nephrology, Department of Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Alexander H J Danser
- Division of Pharmacology and Vascular Medicine, Department of Internal Medicine, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Ewout J Hoorn
- Department of Internel Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Joris I Rotmans
- Department of Internal Medicine, Leiden University Medical Center, Leiden, The Netherlands
| |
Collapse
|
2
|
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.
Collapse
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.
| | | |
Collapse
|
3
|
Gao ZX, Zhou R, Li MY, Li ST, Mao ZH, Shu TT, Liu DW, Liu ZS, Wu P. Activation of Kir4.1/Kir5.1 contributes to the cyclosporin A-induced stimulation of the renal NaCl cotransporter and hyperkalemic hypertension. Acta Physiol (Oxf) 2023; 238:e13948. [PMID: 36764674 DOI: 10.1111/apha.13948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 01/16/2023] [Accepted: 02/07/2023] [Indexed: 02/12/2023]
Abstract
AIM Cyclosporin A (CsA) is a widely used immunosuppressive drug that causes hypertension and hyperkalemia. Moreover, CsA-induced stimulation of the thiazide-sensitive NaCl cotransporter (NCC) in the kidney has been shown to be responsible for the development of hyperkalemic hypertension. In this study, we tested whether CsA induces the activation of NCC by stimulating the basolateral Kir4.1/Kir5.1 channel in the distal convoluted tubule (DCT). METHODS Electrophysiology, immunoblotting, metabolic cages, and radio-telemetry methods were used to examine the effects of CsA on Kir4.1/Kir5.1 activity in the DCT, NCC function, and blood pressure in wild-type (WT) and kidney-specific Kir4.1 knockout (KS-Kir4.1 KO) mice. RESULTS The single-channel patch clamp experiment demonstrated that CsA stimulated the basolateral 40 pS K+ channel in the DCT. Whole-cell recording showed that short-term CsA administration (2 h) not only increased DCT K+ currents but also shifted the K+ current (IK ) reversal potential to the negative range (hyperpolarization). Furthermore, CsA administration increased phosphorylated NCC (pNCC) levels and inhibited renal Na+ and K+ excretions in WT mice but not in KS-Kir4.1 KO mice, suggesting that Kir4.1 is required to mediate CsA effects on NCC function. Finally, long-term CsA infusion (14 days) increased blood pressure, plasma K+ concentration, and total NCC or pNCC abundance in WT mice, but these effects were blunted in KS-Kir4.1 KO mice. CONCLUSION We conclude that CsA stimulates basolateral K+ channel activity in the DCT and that Kir4.1 is essential for CsA-induced NCC activation and hyperkalemic hypertension.
Collapse
Affiliation(s)
- Zhong-Xiuzi Gao
- Traditional Chinese Medicine Integrated Department of Nephrology, 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
| | - Rui Zhou
- Traditional Chinese Medicine Integrated Department of Nephrology, 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
| | - Ming-Yan Li
- Traditional Chinese Medicine Integrated Department of Nephrology, 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
| | - Shu-Ting Li
- Traditional Chinese Medicine Integrated Department of Nephrology, 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
| | - Zi-Hui Mao
- Traditional Chinese Medicine Integrated Department of Nephrology, 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
| | - Ting-Ting Shu
- Traditional Chinese Medicine Integrated Department of Nephrology, 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
| | - Dong-Wei Liu
- Traditional Chinese Medicine Integrated Department of Nephrology, 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
| | - Zhang-Suo Liu
- Traditional Chinese Medicine Integrated Department of Nephrology, 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
| | - Peng Wu
- Traditional Chinese Medicine Integrated Department of Nephrology, 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
| |
Collapse
|
4
|
Wang WH, Lin DH. Inwardly rectifying K + channels 4.1 and 5.1 (Kir4.1/Kir5.1) in the renal distal nephron. Am J Physiol Cell Physiol 2022; 323:C277-C288. [PMID: 35759440 PMCID: PMC9291425 DOI: 10.1152/ajpcell.00096.2022] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The inwardly rectifying potassium channel (Kir) 4.1 (encoded by KCNJ10) interacts with Kir5.1 (encoded by KCNJ16) to form a major basolateral K+ channel in the renal distal convoluted tubule (DCT), connecting tubule (CNT), and the cortical collecting duct (CCD). Kir4.1/Kir5.1 heterotetramer plays an important role in regulating Na+ and K+ transport in the DCT, CNT, and CCD. A recent development in the field has firmly established the role of Kir4.1/Kir5.1 heterotetramer of the DCT in the regulation of thiazide-sensitive Na-Cl cotransporter (NCC). Changes in Kir4.1/Kir5.1 activity of the DCT are an essential step for the regulation of NCC expression/activity induced by dietary K+ and Na+ intakes and play a role in modulating NCC by type 2 angiotensin II receptor (AT2R), bradykinin type II receptor (BK2R), and β-adrenergic receptor. Since NCC activity determines the Na+ delivery rate to the aldosterone-sensitive distal nephron (ASDN), a distal nephron segment from late DCT to CCD, Kir4.1/Kir5.1 activity plays a critical role not only in the regulation of renal Na+ absorption but also in modulating renal K+ excretion and maintaining K+ homeostasis. Thus, Kir4.1/Kir5.1 activity serves as an important component of renal K+ sensing mechanism. The main focus of this review is to provide an overview regarding the role of Kir4.1 and Kir5.1 of the DCT and CCD in the regulation of renal K+ excretion and Na+ absorption.
Collapse
Affiliation(s)
- 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
| |
Collapse
|
5
|
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].
Collapse
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
| |
Collapse
|
6
|
Lo J, Forst AL, Warth R, Zdebik AA. EAST/SeSAME Syndrome and Beyond: The Spectrum of Kir4.1- and Kir5.1-Associated Channelopathies. Front Physiol 2022; 13:852674. [PMID: 35370765 PMCID: PMC8965613 DOI: 10.3389/fphys.2022.852674] [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: 01/11/2022] [Accepted: 02/08/2022] [Indexed: 12/13/2022] Open
Abstract
In 2009, two groups independently linked human mutations in the inwardly rectifying K+ channel Kir4.1 (gene name KCNJ10) to a syndrome affecting the central nervous system (CNS), hearing, and renal tubular salt reabsorption. The autosomal recessive syndrome has been named EAST (epilepsy, ataxia, sensorineural deafness, and renal tubulopathy) or SeSAME syndrome (seizures, sensorineural deafness, ataxia, intellectual disability, and electrolyte imbalance), accordingly. Renal dysfunction in EAST/SeSAME patients results in loss of Na+, K+, and Mg2+ with urine, activation of the renin-angiotensin-aldosterone system, and hypokalemic metabolic alkalosis. Kir4.1 is highly expressed in affected organs: the CNS, inner ear, and kidney. In the kidney, it mostly forms heteromeric channels with Kir5.1 (KCNJ16). Biallelic loss-of-function mutations of Kir5.1 can also have disease significance, but the clinical symptoms differ substantially from those of EAST/SeSAME syndrome: although sensorineural hearing loss and hypokalemia are replicated, there is no alkalosis, but rather acidosis of variable severity; in contrast to EAST/SeSAME syndrome, the CNS is unaffected. This review provides a framework for understanding some of these differences and will guide the reader through the growing literature on Kir4.1 and Kir5.1, discussing the complex disease mechanisms and the variable expression of disease symptoms from a molecular and systems physiology perspective. Knowledge of the pathophysiology of these diseases and their multifaceted clinical spectrum is an important prerequisite for making the correct diagnosis and forms the basis for personalized therapies.
Collapse
Affiliation(s)
- Jacky Lo
- Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
| | - Anna-Lena Forst
- Medical Cell Biology, Institute of Physiology, University of Regensburg, Regensburg, Germany
| | - Richard Warth
- Medical Cell Biology, Institute of Physiology, University of Regensburg, Regensburg, Germany
| | - Anselm A. Zdebik
- Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
- Centre for Nephrology, University College London, London, United Kingdom
| |
Collapse
|
7
|
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.
Collapse
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
| | | |
Collapse
|
8
|
Pearce D, Manis AD, Nesterov V, Korbmacher C. Regulation of distal tubule sodium transport: mechanisms and roles in homeostasis and pathophysiology. Pflugers Arch 2022; 474:869-884. [PMID: 35895103 PMCID: PMC9338908 DOI: 10.1007/s00424-022-02732-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 07/09/2022] [Accepted: 07/11/2022] [Indexed: 02/03/2023]
Abstract
Regulated Na+ transport in the distal nephron is of fundamental importance to fluid and electrolyte homeostasis. Further upstream, Na+ is the principal driver of secondary active transport of numerous organic and inorganic solutes. In the distal nephron, Na+ continues to play a central role in controlling the body levels and concentrations of a more select group of ions, including K+, Ca++, Mg++, Cl-, and HCO3-, as well as water. Also, of paramount importance are transport mechanisms aimed at controlling the total level of Na+ itself in the body, as well as its concentrations in intracellular and extracellular compartments. Over the last several decades, the transporters involved in moving Na+ in the distal nephron, and directly or indirectly coupling its movement to that of other ions have been identified, and their interrelationships brought into focus. Just as importantly, the signaling systems and their components-kinases, ubiquitin ligases, phosphatases, transcription factors, and others-have also been identified and many of their actions elucidated. This review will touch on selected aspects of ion transport regulation, and its impact on fluid and electrolyte homeostasis. A particular focus will be on emerging evidence for site-specific regulation of the epithelial sodium channel (ENaC) and its role in both Na+ and K+ homeostasis. In this context, the critical regulatory roles of aldosterone, the mineralocorticoid receptor (MR), and the kinases SGK1 and mTORC2 will be highlighted. This includes a discussion of the newly established concept that local K+ concentrations are involved in the reciprocal regulation of Na+-Cl- cotransporter (NCC) and ENaC activity to adjust renal K+ secretion to dietary intake.
Collapse
Affiliation(s)
- David Pearce
- Department of Medicine, Division of Nephrology, and Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA USA
| | - Anna D. Manis
- Department of Medicine, Division of Nephrology, and Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA USA
| | - Viatcheslav Nesterov
- Institut für Zelluläre und Molekulare Physiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany, Erlangen, Germany
| | - Christoph Korbmacher
- Institut für Zelluläre und Molekulare Physiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany, Erlangen, Germany
| |
Collapse
|
9
|
Isaeva E, Bohovyk R, Fedoriuk M, Shalygin A, Klemens CA, Zietara A, Levchenko V, Denton JS, Staruschenko A, Palygin O. Crosstalk between ENaC and basolateral K ir 4.1/K ir 5.1 channels in the cortical collecting duct. Br J Pharmacol 2021; 179:2953-2968. [PMID: 34904226 DOI: 10.1111/bph.15779] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 10/06/2021] [Accepted: 12/06/2021] [Indexed: 11/02/2022] Open
Abstract
BACKGROUND AND PURPOSE Inwardly rectifying K+ (Kir ) channels located on the basolateral membrane of epithelial cells of the distal nephron play a crucial role in K+ handling and blood pressure control, making these channels an attractive target for the treatment of hypertension. The purpose of the present study was to determine how the inhibition of basolateral Kir 4.1/Kir 5.1 heteromeric K+ channel affects epithelial sodium channel (ENaC)-mediated Na+ transport in the principal cells of cortical collecting duct (CCD). EXPERIMENTAL APPROACH The effect of fluoxetine, amitriptyline, and recently developed Kir inhibitor, VU0134992, on the activity of Kir 4.1, Kir 4.1/Kir 5.1, and ENaC were tested using electrophysiological approaches in Chinese hamster ovary (CHO) cells transfected with respective channel subunits, cultured polarized epithelial mCCDcl1 cells, and freshly isolated rat and human CCD tubules. To test the effect of pharmacological Kir 4.1/Kir 5.1 inhibition on electrolyte homeostasis in vivo and corresponding changes in distal tubule transport, Dahl salt-sensitive rats were injected with amitriptyline (15 mg kg-1 day-1 ) for three days. KEY RESULTS We found that inhibition of Kir 4.1/Kir 5.1, but not Kir 4.1 channel, depolarizes cell membrane, induces the elevation of intracellular Ca2+ concentration, and suppresses ENaC activity. Furthermore, we demonstrate that amitriptyline administration leads to a significant drop in plasma K+ level, triggering sodium excretion and diuresis. CONCLUSION AND IMPLICATIONS Present data uncovers a specific role of the Kir 4.1/Kir 5.1 channel in the modulation of ENaC activity and emphasizes the potential for using Kir 4.1/Kir 5.1 inhibitors to regulate electrolyte homeostasis and blood pressure.
Collapse
Affiliation(s)
- Elena Isaeva
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA.,Department of Cellular Membranology, Bogomoletz Institute of Physiology, Kyiv, Ukraine
| | - Ruslan Bohovyk
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA.,Department of Cellular Membranology, Bogomoletz Institute of Physiology, Kyiv, Ukraine.,Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, FL, USA
| | - Mykhailo Fedoriuk
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA.,Department of Cellular Membranology, Bogomoletz Institute of Physiology, Kyiv, Ukraine
| | - Alexey Shalygin
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA.,Institute of Cytology of the Russian Academy of Sciences, St. Petersburg, Russia
| | - Christine A Klemens
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA.,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI, USA.,Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, FL, USA
| | - Adrian Zietara
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA.,Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, FL, USA
| | - Vladislav Levchenko
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA.,Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, FL, USA
| | - Jerod S Denton
- Department of Anesthesiology and Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Alexander Staruschenko
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA.,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI, USA.,Clement J. Zablocki VA Medical Center, Milwaukee, WI, USA.,Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, FL, USA
| | - Oleg Palygin
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA.,Department of Medicine, Division of Nephrology, Medical University of South Carolina, Charleston, SC, USA
| |
Collapse
|
10
|
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.
Collapse
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
| |
Collapse
|
11
|
Schlingmann KP, Renigunta A, Hoorn EJ, Forst AL, Renigunta V, Atanasov V, Mahendran S, Barakat TS, Gillion V, Godefroid N, Brooks AS, Lugtenberg D, Lake J, Debaix H, Rudin C, Knebelmann B, Tellier S, Rousset-Rouvière C, Viering D, de Baaij JHF, Weber S, Palygin O, Staruschenko A, Kleta R, Houillier P, Bockenhauer D, Devuyst O, Vargas-Poussou R, Warth R, Zdebik AA, Konrad M. Defects in KCNJ16 Cause a Novel Tubulopathy with Hypokalemia, Salt Wasting, Disturbed Acid-Base Homeostasis, and Sensorineural Deafness. J Am Soc Nephrol 2021; 32:1498-1512. [PMID: 33811157 PMCID: PMC8259640 DOI: 10.1681/asn.2020111587] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 02/04/2021] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND The transepithelial transport of electrolytes, solutes, and water in the kidney is a well-orchestrated process involving numerous membrane transport systems. Basolateral potassium channels in tubular cells not only mediate potassium recycling for proper Na+,K+-ATPase function but are also involved in potassium and pH sensing. Genetic defects in KCNJ10 cause EAST/SeSAME syndrome, characterized by renal salt wasting with hypokalemic alkalosis associated with epilepsy, ataxia, and sensorineural deafness. METHODS A candidate gene approach and whole-exome sequencing determined the underlying genetic defect in eight patients with a novel disease phenotype comprising a hypokalemic tubulopathy with renal salt wasting, disturbed acid-base homeostasis, and sensorineural deafness. Electrophysiologic studies and surface expression experiments investigated the functional consequences of newly identified gene variants. RESULTS We identified mutations in the KCNJ16 gene encoding KCNJ16, which along with KCNJ15 and KCNJ10, constitutes the major basolateral potassium channel of the proximal and distal tubules, respectively. Coexpression of mutant KCNJ16 together with KCNJ15 or KCNJ10 in Xenopus oocytes significantly reduced currents. CONCLUSIONS Biallelic variants in KCNJ16 were identified in patients with a novel disease phenotype comprising a variable proximal and distal tubulopathy associated with deafness. Variants affect the function of heteromeric potassium channels, disturbing proximal tubular bicarbonate handling as well as distal tubular salt reabsorption.
Collapse
Affiliation(s)
- Karl P. Schlingmann
- Department of General Pediatrics, Pediatric Nephrology, University Children’s Hospital, Munster, Germany
| | - Aparna Renigunta
- Department of Pediatric Nephrology, Marburg Kidney Research Center, Philipps University, Marburg, Germany
| | - Ewout J. Hoorn
- Division of Nephrology and Transplantation, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Anna-Lena Forst
- Department of Physiology, Medical Cell Biology, University of Regensburg, Regensburg, Germany
| | - Vijay Renigunta
- Department of Neurophysiology, Institute of Physiology and Pathophysiology, Philipps University, Marburg, Germany
| | - Velko Atanasov
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
| | - Sinthura Mahendran
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
| | | | - Valentine Gillion
- Division of Nephrology, Saint-Luc Academic Hospital, Université Catholique Louvain, Brussels, Belgium
| | - Nathalie Godefroid
- Division of Pediatric Nephrology, Saint-Luc Academic Hospital, Université Catholique Louvain, Brussels, Belgium
| | - Alice S. Brooks
- Department of Clinical Genetics, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Dorien Lugtenberg
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jennifer Lake
- Department of Physiology, Mechanism of Inherited Kidney Disorders, University of Zurich, Zurich, Switzerland
| | - Huguette Debaix
- Department of Physiology, Mechanism of Inherited Kidney Disorders, University of Zurich, Zurich, Switzerland
| | - Christoph Rudin
- Department of Pediatric Nephrology, University Children’s Hospital, Basel, Switzerland
| | - Bertrand Knebelmann
- Department of Nephrology-Transplantation, Assistance Publique Hôpitaux de Paris, Hôpital Necker, Paris, France,Reference Center for Hereditary Kidney and Childhood Diseases (MAladies Renales Hereditaires de l'Enfant et de l'Adulte), Paris, France
| | - Stephanie Tellier
- Department of Pediatric Nephrology, and Rheumatology, French Reference Center of Rare Renal Diseases (SORARE), CHU Toulouse, Toulouse, France,Division of Rheumatology, Department of Pediatrics, Centre Hospitalier Universitaire de Toulouse, Toulouse, France
| | - Caroline Rousset-Rouvière
- Department of Multidisciplinary Pediatrics, Pediatric Nephrology Unit, La Timone, University Hospital of Marseille, Marseille, France
| | - Daan Viering
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jeroen H. F. de Baaij
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Stefanie Weber
- Department of Pediatric Nephrology, Marburg Kidney Research Center, Philipps University, Marburg, Germany
| | - Oleg Palygin
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Alexander Staruschenko
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin,Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin
| | - Robert Kleta
- Department of Renal Medicine, University College London, London, United Kingdom,Department of Paediatric Nephrology, Great Ormond Street Hospital for Children National Health Service Foundation Trust, London, United Kingdom
| | - Pascal Houillier
- Reference Center for Hereditary Kidney and Childhood Diseases (MAladies Renales Hereditaires de l'Enfant et de l'Adulte), Paris, France,Department of Physiology, Assistance Publique Hôpitaux de Paris, Hôpital Européen Georges-Pompidou, Paris, France,Department of Renal Physiology, Centre de Recherche des Cordeliers, Institut National de la Santé et de la Recherche Médicale, Sorbonne Université, Université de Paris, Centre National de la Recherche Scientifique, Paris, France
| | - Detlef Bockenhauer
- Department of Renal Medicine, University College London, London, United Kingdom,Department of Paediatric Nephrology, Great Ormond Street Hospital for Children National Health Service Foundation Trust, London, United Kingdom
| | - Olivier Devuyst
- Division of Nephrology, Saint-Luc Academic Hospital, Université Catholique Louvain, Brussels, Belgium,Department of Physiology, Mechanism of Inherited Kidney Disorders, University of Zurich, Zurich, Switzerland
| | - Rosa Vargas-Poussou
- Reference Center for Hereditary Kidney and Childhood Diseases (MAladies Renales Hereditaires de l'Enfant et de l'Adulte), Paris, France,Department of Renal Physiology, Centre de Recherche des Cordeliers, Institut National de la Santé et de la Recherche Médicale, Sorbonne Université, Université de Paris, Centre National de la Recherche Scientifique, Paris, France,Department of Genetics, Assistance Publique Hôpitaux de Paris, Hôpital Européen Georges-Pompidou, Paris, France
| | - Richard Warth
- Department of Physiology, Medical Cell Biology, University of Regensburg, Regensburg, Germany
| | - Anselm A. Zdebik
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom,Department of Renal Medicine, University College London, London, United Kingdom
| | - Martin Konrad
- Department of General Pediatrics, Pediatric Nephrology, University Children’s Hospital, Munster, Germany
| |
Collapse
|
12
|
Suzumoto Y, Columbano V, Gervasi L, Giunta R, Mattina T, Trimarchi G, Capolongo G, Simeoni M, Perna AF, Zacchia M, Toriello G, Pollastro RM, Rapisarda F, Capasso G, Trepiccione F. A case series of adult patients affected by EAST/SeSAME syndrome suggests more severe disease in subjects bearing KCNJ10 truncating mutations. Intractable Rare Dis Res 2021; 10:95-101. [PMID: 33996354 PMCID: PMC8122315 DOI: 10.5582/irdr.2020.03158] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
EAST/SeSAME syndrome is a rare disease affecting the Central Nervous System (CNS), inner ear, and kidney. The syndrome is due to loss-of-function mutations in the KCNJ10 gene encoding the inward-rectifying potassium channel Kir4.1. EAST/SeSAME syndrome is mainly diagnosed during childhood with a tonic-clonic seizure being the usual first symptom. Due to a limited number of patients and recent identification of the disease, few data are available on the clinical progress of this disease in adulthood. In particular, neurologic and nephrological outcomes have not been reported. We present a case series of 4 adult patients harbouring homozygous missense mutation p.Ala167Val and homozygous frameshift mutations p.Asn232Glnfs*14 and p.Gly275Valfs*7. Effects of these mutations were predicted by in silico modelling and bioinformatic tools. Patients with truncating mutations were associated with more severe outcomes, both in tubulopathy severity and neurological symptomatology. Conversely, either missense or truncating mutations were correlated with similar severity of epilepsy, with a long free-of-event period up to 20 years old. No eGFR decline was documented. Modelling predicted that truncating mutations lead to complete Kir4.1 dysfunction. Finally, all patients had a mild increase in urinary protein excretion. Our study indicates that the prognosis of patients suffering from EAST/SeSAME syndrome is related to the severity of the mutation causing the disease. As predicted by in silico modelling, truncating mutations of KCNJ10 are associated with more severe disease, with recurrence of symptomatic hypokalemia and more severe neurological phenotype. The type of mutation should be considered for the therapy tailored to patients' phenotype.
Collapse
Affiliation(s)
| | - Valeria Columbano
- Department of Translational Medical Sciences, University of Campania "L. Vanvitelli", Naples, Italy
| | - Luciano Gervasi
- School of Nephrology, Department of Clinical and Experimental Medicine, University of Catania, Italy
| | - Rosa Giunta
- School of Nephrology, Department of Clinical and Experimental Medicine, University of Catania, Italy
| | - Teresa Mattina
- Department of Biomedical and Biotechnological Sciences, University of Catania, Italy
| | - Gabriele Trimarchi
- Department of Biomedical and Biotechnological Sciences, University of Catania, Italy
| | - Giovanna Capolongo
- Department of Translational Medical Sciences, University of Campania "L. Vanvitelli", Naples, Italy
| | - Mariadelina Simeoni
- Department of Translational Medical Sciences, University of Campania "L. Vanvitelli", Naples, Italy
| | - Alessandra F. Perna
- Department of Translational Medical Sciences, University of Campania "L. Vanvitelli", Naples, Italy
| | - Miriam Zacchia
- Department of Translational Medical Sciences, University of Campania "L. Vanvitelli", Naples, Italy
| | | | - Rosa M. Pollastro
- Department of Translational Medical Sciences, University of Campania "L. Vanvitelli", Naples, Italy
| | - Francesco Rapisarda
- School of Nephrology, Department of Clinical and Experimental Medicine, University of Catania, Italy
| | - Giovambattista Capasso
- Biogem Research Institute, Ariano Irpino, Italy
- Department of Translational Medical Sciences, University of Campania "L. Vanvitelli", Naples, Italy
| | - Francesco Trepiccione
- Biogem Research Institute, Ariano Irpino, Italy
- Department of Translational Medical Sciences, University of Campania "L. Vanvitelli", Naples, Italy
- Address correspondence to:Francesco Trepiccione, Department of Translational Medical Sciences University of Campania "L.Vanvitelli", Via Pansini n5, 80131 Naples, Italy. E-mail:
| |
Collapse
|