1
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Cheng YYW, Cheng CJ. Mitochondrial bioenergetics: coupling of transport to tubular mitochondrial metabolism. Curr Opin Nephrol Hypertens 2024; 33:405-413. [PMID: 38573234 PMCID: PMC11145760 DOI: 10.1097/mnh.0000000000000986] [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] [Indexed: 04/05/2024]
Abstract
PURPOSE OF REVIEW Renal tubules have robust active transport and mitochondrial metabolism, which are functionally coupled to maintain energy homeostasis. Here, I review the current literature and our recent efforts to examine mitochondrial adaptation to different transport activities in renal tubules. RECENT FINDINGS The advance of extracellular flux analysis (EFA) allows real-time assessments of mitochondrial respiration, glycolysis, and oxidation of energy substrates. We applied EFA assays to freshly isolated mouse proximal tubules, thick ascending limbs (TALs), and distal convoluted tubules (DCTs) and successfully differentiated their unique metabolic features. We found that TALs and DCTs adjusted their mitochondrial bioenergetics and biogenesis in response to acute and chronic alterations of transport activity. Based on the literature and our recent findings, I discuss working models and mechanisms underlying acute and chronic tubular adaptations to transport activity. The potential roles of peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α), AMP-activated protein kinase (AMPK), and uncoupling protein 2 (UCP2) are discussed. SUMMARY Mitochondria in renal tubules are highly plastic to accommodate different transport activities. Understanding the mechanisms may improve the treatment of renal tubulopathies.
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Affiliation(s)
- Yong-Yao W. Cheng
- Division of Nephrology, Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Chih-Jen Cheng
- Division of Nephrology, Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
- Division of Nephrology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
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2
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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 PMCID: PMC11381001 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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Bargagli M, Anderegg MA, Fuster DG. Effects of thiazides and new findings on kidney stones and dysglycemic side effects. Acta Physiol (Oxf) 2024; 240:e14155. [PMID: 38698738 DOI: 10.1111/apha.14155] [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: 02/22/2024] [Revised: 04/08/2024] [Accepted: 04/22/2024] [Indexed: 05/05/2024]
Abstract
Thiazide and thiazide-like diuretics (thiazides) belong to the most frequently prescribed drugs worldwide. By virtue of their natriuretic and vasodilating properties, thiazides effectively lower blood pressure and prevent adverse cardiovascular outcomes. In addition, through their unique characteristic of reducing urine calcium, thiazides are also widely employed for the prevention of kidney stone recurrence and reduction of bone fracture risk. Since their introduction into clinical medicine in the early 1960s, thiazides have been recognized for their association with metabolic side effects, particularly impaired glucose tolerance, and new-onset diabetes mellitus. Numerous hypotheses have been advanced to explain thiazide-induced glucose intolerance, yet underlying mechanisms remain poorly defined. Regrettably, the lack of understanding and unpredictability of these side effects has prompted numerous physicians to refrain from prescribing these effective, inexpensive, and widely accessible drugs. In this review, we outline the pharmacology and mechanism of action of thiazides, highlight recent advances in the understanding of thiazide-induced glucose intolerance, and provide an up-to-date discussion on the role of thiazides in kidney stone prevention.
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Affiliation(s)
- Matteo Bargagli
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Swiss National Centre of Competence in Research (NCCR) Kidney.CH, University of Zürich, Zürich, Switzerland
- Department for Biomedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Manuel A Anderegg
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Swiss National Centre of Competence in Research (NCCR) Kidney.CH, University of Zürich, Zürich, Switzerland
- Department for Biomedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Daniel G Fuster
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Swiss National Centre of Competence in Research (NCCR) Kidney.CH, University of Zürich, Zürich, Switzerland
- Department for Biomedical Research (DBMR), University of Bern, Bern, Switzerland
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4
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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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5
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Zhang J. Hereditary causes of hypertension due to increased sodium transport. Curr Opin Pediatr 2024; 36:211-218. [PMID: 37909881 DOI: 10.1097/mop.0000000000001304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2023]
Abstract
PURPOSE OF REVIEW Hypertension, commonly known as high blood pressure, is a widespread health condition affecting a large number of individuals across the globe. Although lifestyle choices and environmental factors are known to have a significant impact on its development, there is growing recognition of the influence of genetic factors in the pathogenesis of hypertension. This review specifically focuses on the hereditary causes of hypertension that are associated with increased sodium transport through the thiazide-sensitive NaCl cotransporter (NCC) or amiloride-sensitive epithelial sodium channel (ENaC), crucial mechanisms involved in regulating blood pressure in the kidneys. By examining genetic mutations and signaling molecules linked to the dysregulation of sodium transport, this review aims to deepen our understanding of the hereditary causes of hypertension and shed light on potential therapeutic targets. RECENT FINDINGS Liddle syndrome (LS) is a genetic disorder that typically manifests early in life and is characterized by hypertension, hypokalemic metabolic alkalosis, hyporeninemia, and suppressed aldosterone secretion. This condition is primarily caused by gain-of-function mutations in ENaC. In contrast, Pseudohypoaldosteronism type II (PHAII) is marked by hyperkalemia and hypertension, alongside other clinical features such as hyperchloremia, metabolic acidosis, and suppressed plasma renin levels. PHAII results from overactivations of NCC, brought about by gain-of-function mutations in its upstream signaling molecules, including WNK1 (with no lysine (K) 1), WNK4, Kelch-like 3 (KLHL3), and cullin3 (CUL3). SUMMARY NCC and ENaC are integral components, and their malfunctions lead to disorders like LS and PHAII, hereditary causes of hypertension. Current treatments for LS involve ENaC blockers (e.g., triamterene and amiloride) in conjunction with low-sodium diets, effectively normalizing blood pressure and potassium levels. In PHAII, thiazide diuretics, which inhibit NCC, are the mainstay treatment, albeit with some limitations and potential side effects. Ongoing research in developing alternative treatments, including small molecules targeting key regulators, holds promise for more effective and tailored hypertension solutions.
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Affiliation(s)
- Jinwei Zhang
- Xiamen Cardiovascular Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian
- State Key Laboratory of Chemical Biology, Research Center of Chemical Kinomics, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, China
- Institute of Biomedical and Clinical Sciences, Medical School, Faculty of Health and Life Sciences, University of Exeter, Hatherly Laboratories, Exeter, UK
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Abstract
Excessive salt intake raises blood pressure, but the implications of this observation for human health have remained contentious. It has also been recognized for many years that potassium intake may mitigate the effects of salt intake on blood pressure and possibly on outcomes such as stroke. Recent large randomized intervention trials have provided strong support for the benefits of replacing salt (NaCl) with salt substitute (75% NaCl, 25% KCl) on hard outcomes, including stroke. During the same period of time, major advances have been made in understanding how the body senses and tastes salt, and how these sensations drive intake. Additionally, new insights into the complex interactions between systems that control sodium and potassium excretion by the kidneys, and the brain have highlighted the existence of a potassium switch in the kidney distal nephron. This switch seems to contribute importantly to the blood pressure-lowering effects of potassium intake. In recognition of these evolving data, the United States Food and Drug Administration is moving to permit potassium-containing salt substitutes in food manufacturing. Given that previous attempts to reduce salt consumption have not been successful, this new approach has a chance of improving health and ending the 'Salt Wars'.
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Affiliation(s)
- Robert Little
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
- LeDucq Transatlantic Network of Excellence
| | - David H. Ellison
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon, USA
- Oregon Clinical & Translational Research Institute, Oregon Health & Science University, Portland, Oregon, USA
- LeDucq Transatlantic Network of Excellence
- VA Portland Health Care System, Portland, OR
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7
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Hoogstraten CA, Hoenderop JG, de Baaij JHF. Mitochondrial Dysfunction in Kidney Tubulopathies. Annu Rev Physiol 2024; 86:379-403. [PMID: 38012047 DOI: 10.1146/annurev-physiol-042222-025000] [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] [Indexed: 11/29/2023]
Abstract
Mitochondria play a key role in kidney physiology and pathology. They produce ATP to fuel energy-demanding water and solute reabsorption processes along the nephron. Moreover, mitochondria contribute to cellular health by the regulation of autophagy, (oxidative) stress responses, and apoptosis. Mitochondrial abundance is particularly high in cortical segments, including proximal and distal convoluted tubules. Dysfunction of the mitochondria has been described for tubulopathies such as Fanconi, Gitelman, and Bartter-like syndromes and renal tubular acidosis. In addition, mitochondrial cytopathies often affect renal (tubular) tissues, such as in Kearns-Sayre and Leigh syndromes. Nevertheless, the mechanisms by which mitochondrial dysfunction results in renal tubular diseases are only scarcely being explored. This review provides an overview of mitochondrial dysfunction in the development and progression of kidney tubulopathies. Furthermore, it emphasizes the need for further mechanistic investigations to identify links between mitochondrial function and renal electrolyte reabsorption.
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Affiliation(s)
- Charlotte A Hoogstraten
- Department of Medical Biosciences, Radboud University Medical Center, Nijmegen, The Netherlands;
| | - Joost G Hoenderop
- Department of Medical Biosciences, Radboud University Medical Center, Nijmegen, The Netherlands;
| | - Jeroen H F de Baaij
- Department of Medical Biosciences, Radboud University Medical Center, Nijmegen, The Netherlands;
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Maeoka Y, Nguyen LT, Sharma A, Cornelius RJ, Su XT, Gutierrez MR, Carbajal-Contreras H, Castañeda-Bueno M, Gamba G, McCormick JA. Dysregulation of the WNK4-SPAK/OSR1 pathway has a minor effect on baseline NKCC2 phosphorylation. Am J Physiol Renal Physiol 2024; 326:F39-F56. [PMID: 37881876 DOI: 10.1152/ajprenal.00100.2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 10/12/2023] [Accepted: 10/13/2023] [Indexed: 10/27/2023] Open
Abstract
The with-no-lysine kinase 4 (WNK4)-sterile 20/SPS-1-related proline/alanine-rich kinase (SPAK)/oxidative stress-responsive kinase 1 (OSR1) pathway mediates activating phosphorylation of the furosemide-sensitive Na+-K+-2Cl- cotransporter (NKCC2) and the thiazide-sensitive NaCl cotransporter (NCC). The commonly used pT96/pT101-pNKCC2 antibody cross-reacts with pT53-NCC in mice on the C57BL/6 background due to a five amino acid deletion. We generated a new C57BL/6-specific pNKCC2 antibody (anti-pT96-NKCC2) and tested the hypothesis that the WNK4-SPAK/OSR1 pathway strongly regulates the phosphorylation of NCC but not NKCC2. In C57BL/6 mice, anti-pT96-NKCC2 detected pNKCC2 and did not cross-react with NCC. Abundances of pT96-NKCC2 and pT53-NCC were evaluated in Wnk4-/-, Osr1-/-, Spak-/-, and Osr1-/-/Spak-/- mice and in several models of the disease familial hyperkalemic hypertension (FHHt) in which the CUL3-KLHL3 ubiquitin ligase complex that promotes WNK4 degradation is dysregulated (Cul3+/-/Δ9, Klhl3-/-, and Klhl3R528H/R528H). All mice were on the C57BL/6 background. In Wnk4-/- mice, pT53-NCC was almost absent but pT96-NKCC2 was only slightly lower. pT53-NCC was almost absent in Spak-/- and Osr1-/-/Spak-/- mice, but pT96-NKCC2 abundance did not differ from controls. pT96-NKCC2/total NKCC2 was slightly lower in Osr1-/- and Osr1-/-/Spak-/- mice. WNK4 expression colocalized not only with NCC but also with NKCC2 in Klhl3-/- mice, but pT96-NKCC2 abundance was unchanged. Consistent with this, furosemide-induced urinary Na+ excretion following thiazide treatment was similar between Klhl3-/- and controls. pT96-NKCC2 abundance was also unchanged in the other FHHt mouse models. Our data show that disruption of the WNK4-SPAK/OSR1 pathway only mildly affects NKCC2 phosphorylation, suggesting a role for other kinases in NKCC2 activation. In FHHt models NKCC2 phosphorylation is unchanged despite higher WNK4 abundance, explaining the thiazide sensitivity of FHHt.NEW & NOTEWORTHY The renal cation cotransporters NCC and NKCC2 are activated following phosphorylation mediated by the WNK4-SPAK/OSR1 pathway. While disruption of this pathway strongly affects NCC activity, effects on NKCC2 activity are unclear since the commonly used phospho-NKCC2 antibody was recently reported to cross-react with phospho-NCC in mice on the C57BL/6 background. Using a new phospho-NKCC2 antibody specific for C57BL/6, we show that inhibition or activation of the WNK4-SPAK/OSR1 pathway in mice only mildly affects NKCC2 phosphorylation.
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Affiliation(s)
- Yujiro Maeoka
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon, United States
| | - Luan T Nguyen
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon, United States
| | - Avika Sharma
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon, United States
| | - Ryan J Cornelius
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon, United States
| | - Xiao-Tong Su
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon, United States
| | - Marissa R Gutierrez
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon, United States
| | - Héctor Carbajal-Contreras
- Department of Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - María Castañeda-Bueno
- Department of Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - Gerardo Gamba
- Department of Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
- Molecular Physiology Unit, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - James A McCormick
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon, United States
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Hakimi S, Dutta P, Layton AT. Coupling of renal sodium and calcium transport: a modeling analysis of transporter inhibition and sex differences. Am J Physiol Renal Physiol 2023; 325:F536-F551. [PMID: 37615047 DOI: 10.1152/ajprenal.00145.2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 08/17/2023] [Accepted: 08/17/2023] [Indexed: 08/25/2023] Open
Abstract
Ca2+ transport along the nephron occurs via specific transcellular and paracellular pathways and is coupled to the transport of other electrolytes. Notably, Na+ transport establishes an electrochemical gradient to drive Ca2+ reabsorption. Hence, alterations in renal Na+ handling, under pathophysiological conditions or pharmacological manipulations, can have major effects on Ca2+ transport. An important class of pharmacological agent is diuretics, which are commonly prescribed for the management of blood pressure and fluid balance. The pharmacological targets of diuretics generally directly facilitate Na+ transport but also indirectly affect renal Ca2+ handling. To better understand the underlying mechanisms, we developed a computational model of electrolyte transport along the superficial nephron in the kidney of a male and female rat. Sex differences in renal Ca2+ handling are represented. Model simulations predicted in the female rat nephron lower Ca2+ reabsorption in the proximal tubule and thick ascending limb, but higher reabsorption in the late distal convoluted tubule and connecting tubule, compared with the male nephron. The male rat kidney model yielded a higher urinary Ca2+ excretion than the female model, consistent with animal experiments. Model results indicated that along the proximal tubule and thick ascending limb, Ca2+ and Na+ transport occurred in parallel, but those processes were dissociated in the distal convoluted tubule. Additionally, we conducted simulations of inhibition of channels and transporters that play a major role in Na+ and Ca2+ transport. Simulation results revealed alterations in transepithelial Ca2+ transport, with differential effects among nephron segments and between the sexes.NEW & NOTEWORTHY The kidney plays an important role in the maintenance of whole body Ca2+ balance by regulating Ca2+ reabsorption and excretion. This computational modeling study provides insights into how Ca2+ transport along the nephron is coupled to Na+. Model results indicated that along the proximal tubule and thick ascending limb, Ca2+ and Na+ transport occur in parallel, but those processes were dissociated in the distal convoluted tubule. Simulations also revealed sex-specific responses to different pharmacological manipulations.
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Affiliation(s)
- Shervin Hakimi
- Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario, Canada
| | - Pritha Dutta
- Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario, Canada
| | - Anita T Layton
- Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario, Canada
- Department of Biology, Cheriton School of Computer Science, and School of Pharmacology, University of Waterloo, Waterloo, Ontario, Canada
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10
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Bonnard B, El Moghrabi S, Ueda K, Lattenist L, Soulie M, López-Andrés N, Xhaard C, Shimosawa T, Rossignol P, Jaisser F. NGAL is a Novel Target in Hypertension by Modulating the NCC-Mediated Renal Na Balance. Hypertension 2023; 80:1860-1870. [PMID: 37377014 DOI: 10.1161/hypertensionaha.123.21156] [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: 04/06/2023] [Accepted: 06/12/2023] [Indexed: 06/29/2023]
Abstract
BACKGROUND The expression of NGAL/lcn2 (neutrophil gelatinase-associated lipocalin) is directly modulated by mineralocorticoid receptor activation but its role in blood pressure control is unclear. METHODS a potential relationship between NGAL plasma levels, systolic blood pressure and urinary Na excretion was assessed in the STANISLAS cohort. The specific role of NGAL/lcn2 in salt-sensitive hypertension was studied using lcn2-knockout mice (lcn2 KO) fed with low-Na diet (0Na). RESULTS we show that NGAL plasma levels positively correlate with systolic blood pressure, whereas they negatively correlate with urinary Na excretion in subjects of the STANISLAS cohort. Prolonged feeding of lcn2 KO mice with a 0Na diet induced lower systolic blood pressure than that of the control group (wildtype), suggesting a role for NGAL/lcn2 in Na-balance homeostasis. Short-term or prolonged 0Na increased Na-Cl cotransporter (NCC) phosphorylation in the cortex of wildtype mice, which was prevented in lcn2 KO mice. Recombinant mouse lcn2 injections in lcn2 KO mice induced NCC phosphorylation in the kidney cortex, associated with decreased urinary Na excretion. Ex vivo experiments using kidney slices from lcn2 KO mice showed increased NCC phosphorylation by recombinant murine lcn2. In addition, recombinant murine lcn2 induced activation of CamK2β (calcium/calmodulin-dependent protein kinase II β subunit) phosphorylation in lcn2 KO mice and in kidney slices, providing an underlying mechanism involved in lcn2-induced NCC phosphorylation. Indeed, the inhibition of CamK2β prevented NCC phosphorylation induced by recombinant lcn2 in kidney slices. CONCLUSIONS we highlight a novel role of NGAL/lcn2 as a modulator of the activity of the renal sodium transporter NCC affecting salt-sensitive blood pressure.
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Affiliation(s)
- Benjamin Bonnard
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, France (B.B., S.E.M., K.U., L.L., M.S., F.J.)
| | - Soumaya El Moghrabi
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, France (B.B., S.E.M., K.U., L.L., M.S., F.J.)
| | - Kohei Ueda
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, France (B.B., S.E.M., K.U., L.L., M.S., F.J.)
| | - Lionel Lattenist
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, France (B.B., S.E.M., K.U., L.L., M.S., F.J.)
| | - Matthieu Soulie
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, France (B.B., S.E.M., K.U., L.L., M.S., F.J.)
| | - Natalia López-Andrés
- Cardiovascular Translational Research, Navarrabiomed (Miguel Servet Foundation), Instituto de Investigación Sanitaria de Navarra (IdiSNA), Pamplona, Spain (N.L.-A.)
| | - Constance Xhaard
- Universite de Lorraine, Centre d'Investigations Cliniques-1433, Inserm U1116, CHRU Nancy, and F-CRIN INI-CRCT (Cardiovascular and Renal Clinical Trialists), Nancy, France (C.X., P.R.)
- Medicine and nephrology-dialysis departments, Princess Grace Hospital, and Monaco Private Hemodialysis Centre, Monaco (C.X., P.R., F.J.)
| | - Tatsuo Shimosawa
- Department of Clinical Laboratory, School of Medicine, International University of Health and Welfare, Narita, Chiba, Japan (T.S.)
| | - Patrick Rossignol
- Universite de Lorraine, Centre d'Investigations Cliniques-1433, Inserm U1116, CHRU Nancy, and F-CRIN INI-CRCT (Cardiovascular and Renal Clinical Trialists), Nancy, France (C.X., P.R.)
- Medicine and nephrology-dialysis departments, Princess Grace Hospital, and Monaco Private Hemodialysis Centre, Monaco (C.X., P.R., F.J.)
| | - Frédéric Jaisser
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, France (B.B., S.E.M., K.U., L.L., M.S., F.J.)
- Medicine and nephrology-dialysis departments, Princess Grace Hospital, and Monaco Private Hemodialysis Centre, Monaco (C.X., P.R., F.J.)
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11
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Abstract
Mg2+ is essential for many cellular and physiological processes, including muscle contraction, neuronal activity, and metabolism. Consequently, the blood Mg2+ concentration is tightly regulated by balanced intestinal Mg2+ absorption, renal Mg2+ excretion, and Mg2+ storage in bone and soft tissues. In recent years, the development of novel transgenic animal models and identification of Mendelian disorders has advanced our current insight in the molecular mechanisms of Mg2+ reabsorption in the kidney. In the proximal tubule, Mg2+ reabsorption is dependent on paracellular permeability by claudin-2/12. In the thick ascending limb of Henle's loop, the claudin-16/19 complex provides a cation-selective pore for paracellular Mg2+ reabsorption. The paracellular Mg2+ reabsorption in this segment is regulated by the Ca2+-sensing receptor, parathyroid hormone, and mechanistic target of rapamycin (mTOR) signaling. In the distal convoluted tubule, the fine tuning of Mg2+ reabsorption takes place by transcellular Mg2+ reabsorption via transient receptor potential melastatin-like types 6 and 7 (TRPM6/TRPM7) divalent cation channels. Activity of TRPM6/TRPM7 is dependent on hormonal regulation, metabolic activity, and interacting proteins. Basolateral Mg2+ extrusion is still poorly understood but is probably dependent on the Na+ gradient. Cyclin M2 and SLC41A3 are the main candidates to act as Na+/Mg2+ exchangers. Consequently, disturbances of basolateral Na+/K+ transport indirectly result in impaired renal Mg2+ reabsorption in the distal convoluted tubule. Altogether, this review aims to provide an overview of the molecular mechanisms of Mg2+ reabsorption in the kidney, specifically focusing on transgenic mouse models and human hereditary diseases.
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Affiliation(s)
- Jeroen H F de Baaij
- Department of Physiology, Radboud University Medical Center, Nijmegen, The Netherlands
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12
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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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13
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R158Q and G212S, novel pathogenic compound heterozygous variants in SLC12A3 of Gitelman syndrome. Front Med 2022; 16:932-945. [PMID: 36370249 DOI: 10.1007/s11684-022-0963-9] [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: 05/26/2022] [Accepted: 09/06/2022] [Indexed: 11/14/2022]
Abstract
The dysfunction of Na+-Cl- cotransporter (NCC) caused by mutations in solute carrier family12, member 3 gene (SLC12A3) primarily causes Gitelman syndrome (GS). In identifying the pathogenicity of R158Q and G212S variants of SLC12A3, we evaluated the pathogenicity by bioinformatic, expression, and localization analysis of two variants from a patient in our cohort. The prediction of mutant protein showed that p.R158Q and p.G212S could alter protein's three-dimensional structure. Western blot showed a decrease of mutant Ncc. Immunofluorescence of the two mutations revealed a diffuse positive staining below the plasma membrane. Meanwhile, we conducted a compound heterozygous model-Ncc R156Q/G210S mice corresponding to human NCC R158Q/G212S. NccR156Q/G210S mice clearly exhibited typical GS features, including hypokalemia, hypomagnesemia, and increased fractional excretion of K+ and Mg2+ with a normal blood pressure level, which made NccR156Q/G210S mice an optimal mouse model for further study of GS. A dramatic decrease and abnormal localization of the mutant Ncc in distal convoluted tubules contributed to the phenotype. The hydrochlorothiazide test showed a loss of function of mutant Ncc in NccR156Q/G210S mice. These findings indicated that R158Q and G212S variants of SLC12A3 were pathogenic variants of GS.
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14
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Ilenwabor BP, Schigt H, Kompatscher A, Bos C, Zuidscherwoude M, van der Eerden BCJ, Hoenderop JGJ, de Baaij JHF. FAM111A is dispensable for electrolyte homeostasis in mice. Sci Rep 2022; 12:10211. [PMID: 35715480 PMCID: PMC9205974 DOI: 10.1038/s41598-022-14054-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 05/31/2022] [Indexed: 11/24/2022] Open
Abstract
Autosomal dominant mutations in FAM111A are causative for Kenny-Caffey syndrome type 2. Patients with Kenny-Caffey syndrome suffer from severe growth retardation, skeletal dysplasia, hypoparathyroidism, hypocalcaemia, hyperphosphataemia and hypomagnesaemia. While recent studies have reported FAM111A to function in antiviral response and DNA replication, its role in regulating electrolyte homeostasis remains unknown. In this study, we assessed the role of FAM111A in the regulation of serum electrolyte balance using a Fam111a knockout (Fam111a-/-) C57BL/6 N mouse model. Fam111a-/- mice displayed normal weight and serum parathyroid hormone (PTH) concentration and exhibited unaltered magnesium, calcium and phosphate levels in serum and 24-hour urine. Expression of calciotropic (including Cabp28k, Trpv5, Klotho and Cyp24a1), magnesiotropic (including Trpm6, Trpm7, Cnnm2 and Cnnm4) and phosphotropic (Slc20a1, Slc20a2, Slc34a1 and Slc34a3) genes in the kidneys, duodenum and colon were not affected by Fam111a depletion. Only Slc34a2 expression was significantly upregulated in the duodenum, but not in the colon. Analysis of femurs showed unaffected bone morphology and density in Fam111a-/- mice. Kidney and parathyroid histology were also normal in Fam111a-/- mice. In conclusion, our study is the first to characterise the function of FAM111A in vivo and we report that mice lacking FAM111A exhibit normal electrolyte homeostasis on a standard diet.
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Affiliation(s)
- Barnabas P Ilenwabor
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Heidi Schigt
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Andreas Kompatscher
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Caro Bos
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Malou Zuidscherwoude
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Bram C J van der Eerden
- Department of Internal Medicine, Erasmus MC, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Joost G J Hoenderop
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Jeroen H F de Baaij
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands.
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15
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Flisiński M, Skalska E, Mączyńska B, Butt-Hussaim N, Sobczyńska-Tomaszewska A, Haus O, Manitius J. Gitelman syndrome with normocalciuria - a case report. BMC Nephrol 2022; 23:170. [PMID: 35509038 PMCID: PMC9069753 DOI: 10.1186/s12882-022-02782-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 04/08/2022] [Indexed: 11/16/2022] Open
Abstract
Background Gitelman Syndrome (GS) is a hereditary tubulopathy associated with a biallelic inactivating mutations of the SLC12A3 gene encoding the thiazide-sensitive sodium-chloride cotransporter (NCCT). The typical clinical manifestation is a hypokalemic metabolic alkalosis with significant hypomagnesemia, and low urinary calcium excretion. Hypocalciuria is widely believed to be a hallmark of GS that distinguishes it from Barter’s syndrome, presenting as hypercalciuria. The pathomechanism of hypocalciuria in GS is not fully elucidated. Up to date, a clinical course of GS with normocalciuria has been reported only in men, while women have a milder course of the disease with typical hypocalciuria, which is believed as the result of sex hormone. Additionally, there is a growing evidence that calcium channels of the distal nephron could be regulated by a variety of hormones, including aldosterone (Aldo). Case presentation We present the case of a 28-year-old Caucasian woman with asymptomatic, chronic hypokalemia, hypomagnesemia, hypochloremic alkalosis and normal urinary calcium excretion. A high renin levels with normal concentration of Aldo in serum have also been found. The values of blood pressure were low. Based on genetic studies, two heterozygous mutations in the trans position were confirmed: c.2186G>T (p.Gly729Val) and c.1247G>C (p.Cys416Ser) in the SLC12A3 gene, which ultimately confirmed the diagnosis of GS. Conclusions We report here the first case of genetically confirmed GS manifested as normocalciuria in a Caucasian woman. Thus, our result does not confirm a role of sex hormones on the level of calciuria. Based on the results of normal Aldo concentration despite high renin level in our patient, we hypothesized that Aldo may be connecting with the level of urinary calcium excretion in patients with the GS.
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Affiliation(s)
- Mariusz Flisiński
- Department of Nephrology, Hypertension and Internal Medicine, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, ul. Curie-Skłodowskiej 9, 85-094, Bydgoszcz, Poland.
| | - Ewa Skalska
- Student's Scientific Association of Department of Nephrology, Hypertension and Internal Medicine, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, ul. Curie-Skłodowskiej 9, 85-094, Bydgoszcz, Poland
| | - Barbara Mączyńska
- Student's Scientific Association of Department of Nephrology, Hypertension and Internal Medicine, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, ul. Curie-Skłodowskiej 9, 85-094, Bydgoszcz, Poland
| | - Natalia Butt-Hussaim
- Department of Nephrology, Hypertension and Internal Medicine, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, ul. Curie-Skłodowskiej 9, 85-094, Bydgoszcz, Poland
| | | | - Olga Haus
- Department of Clinical Genetics, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, ul. Curie-Skłodowskiej 9, 85-094, Bydgoszcz, Poland
| | - Jacek Manitius
- Department of Nephrology, Hypertension and Internal Medicine, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, ul. Curie-Skłodowskiej 9, 85-094, Bydgoszcz, Poland
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16
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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.
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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
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17
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Tang W, Chai Y, Jia H, Wang B, Liu T, Wang H, Dai C. Different roles of the RAAS affect bone metabolism in patients with primary aldosteronism, Gitelman syndrome and Bartter syndrome. BMC Endocr Disord 2022; 22:38. [PMID: 35148746 PMCID: PMC8840772 DOI: 10.1186/s12902-022-00955-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 02/07/2022] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Components of the RAAS may influence bone metabolism. Different roles of the RAAS are found in patients with primary aldosteronism (PA), Gitelman syndrome (GS) and Bartter syndrome (BS). We collected inpatient medical records including 20 patients with Gitelman syndrome (GS group), 17 patients with Bartter syndrome (BS group) and 20 age-matched patients with primary aldosteronism (PA group). We found the following results. (1) PA patients had significantly higher serum magnesium, potassium, plasma aldosterone, serum parathyroid hormone, urinary calcium and BMI (p<0.05) while significantly lower serum calcium and phosphorus (P < 0.05) than GS and BS patients. (2) Total hip and femoral neck bone mineral density (BMD) in PA patients were significantly lower than those in GS and BS patients (P<0.05). (3) GS patients had lower serum magnesium and urinary calcium than BS patients (P < 0.05). (4) Compared with BS patients, the vertebral BMD in GS patients were significantly higher (P < 0.05). So we believe higher aldosterone and PTH levels may be the reason that PA patients have lower hip BMD. Lower urinary calcium and inactivation of the NCC gene (Na-Cl cotransporter) in GS patients may have protective effects on vertebral bone mineral density. CONCLUSIONS With persistence disordered RAAS, PA patients have lower BMD, especially hip BMD as compared with GS and BS patients. We presumed the lower renin and higher aldosterone level may be the reason. With the same level of renin and aldosterone, BS patients have lower vertebrate BMD than GS patients. Decreased urinary calcium excretion may be the reason.
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Affiliation(s)
- Wangna Tang
- Endocrinology and Metabolism Disease Department, Tianjin Medical University General Hospital, 154# Anshan Road, Heping District, Tianjin, 300052, China
| | - Yun Chai
- Endocrinology and Metabolism Disease Department, Tianjin Medical University General Hospital, 154# Anshan Road, Heping District, Tianjin, 300052, China
| | - Hongwei Jia
- Endocrinology and Metabolism Disease Department, Tianjin Medical University General Hospital, 154# Anshan Road, Heping District, Tianjin, 300052, China
| | - Baoping Wang
- Endocrinology and Metabolism Disease Department, Tianjin Medical University General Hospital, 154# Anshan Road, Heping District, Tianjin, 300052, China
| | - Tong Liu
- Endocrinology and Metabolism Disease Department, Tianjin Medical University General Hospital, 154# Anshan Road, Heping District, Tianjin, 300052, China
| | - Hao Wang
- Endocrinology and Metabolism Disease Department, Tianjin Medical University General Hospital, 154# Anshan Road, Heping District, Tianjin, 300052, China
| | - Chenlin Dai
- Endocrinology and Metabolism Disease Department, Tianjin Medical University General Hospital, 154# Anshan Road, Heping District, Tianjin, 300052, China.
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18
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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.
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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
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19
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Abstract
Cystinosis is a rare inheritable lysosomal storage disorder characterized by cystine accumulation throughout the body, chronic kidney disease necessitating renal replacement therapy mostly during adolescence, and multiple extra-renal complications. The majority of male cystinosis patients are infertile due to azoospermia, in contrast to female patients who are fertile. Over recent decades, the fertility status of male patients has evolved from a primary hypogonadism in the era before the systematic treatment with cysteamine to azoospermia in the majority of cysteamine-treated infantile cystinosis patients. In this review, we provide a state-of-the-art overview on the available clinical, histopathological, animal, and in vitro data. We summarize current insights on both cystinosis males and females, and their clinical implications including the potential effect of cysteamine on fertility. In addition, we identify the remaining challenges and areas for future research.
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20
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Soliman RH, Pollock DM. Circadian Control of Sodium and Blood Pressure Regulation. Am J Hypertens 2021; 34:1130-1142. [PMID: 34166494 PMCID: PMC9526808 DOI: 10.1093/ajh/hpab100] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 05/12/2021] [Accepted: 06/23/2021] [Indexed: 01/26/2023] Open
Abstract
The attention for the control of dietary risk factors involved in the development of hypertension, includes a large effort on dietary salt restrictions. Ample studies show the beneficial role of limiting dietary sodium as a lifestyle modification in the prevention and management of essential hypertension. Not until the past decade or so have studies more specifically investigated diurnal variations in renal electrolyte excretion, which led us to the hypothesis that timing of salt intake may impact cardiovascular health and blood pressure regulation. Cell autonomous molecular clocks as the name implies, function independently to maintain optimum functional rhythmicity in the face of environmental stressors such that cellular homeostasis is maintained at all times. Our understanding of mechanisms influencing diurnal patterns of sodium excretion and blood pressure has expanded with the discovery of the circadian clock genes. In this review, we discuss what is known about circadian regulation of renal sodium handling machinery and its influence on blood pressure regulation, with timing of sodium intake as a potential modulator of the kidney clock.
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Affiliation(s)
- Reham H Soliman
- Section of Cardio-renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - David M Pollock
- Section of Cardio-renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
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21
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Abstract
Nephrolithiasis is a worldwide problem with increasing prevalence, enormous costs, and significant morbidity. Calcium-containing kidney stones are by far the most common kidney stones encountered in clinical practice. Consequently, hypercalciuria is the greatest risk factor for kidney stone formation. Hypercalciuria can result from enhanced intestinal absorption, increased bone resorption, or altered renal tubular transport. Kidney stone formation is complex and driven by high concentrations of calcium-oxalate or calcium-phosphate in the urine. After discussing the mechanism mediating renal calcium salt precipitation, we review recent discoveries in renal tubular calcium transport from the proximal tubule, thick ascending limb, and distal convolution. Furthermore, we address how calcium is absorbed from the intestine and mobilized from bone. The effect of acidosis on bone calcium resorption and urinary calcium excretion is also considered. Although recent discoveries provide insight into these processes, much remains to be understood in order to provide improved therapies for hypercalciuria and prevent kidney stone formation. Expected final online publication date for the Annual Review of Physiology, Volume 84 is February 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- R T Alexander
- Departments of Physiology and Pediatrics, University of Alberta, Edmonton, Canada; .,Membrane Protein Disease Research Group, University of Alberta, Edmonton, Canada
| | - D G Fuster
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - H Dimke
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark.,Department of Nephrology, Odense University Hospital, Odense, Denmark
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22
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Portioli C, Ruiz Munevar MJ, De Vivo M, Cancedda L. Cation-coupled chloride cotransporters: chemical insights and disease implications. TRENDS IN CHEMISTRY 2021; 3:832-849. [PMID: 34604727 PMCID: PMC8461084 DOI: 10.1016/j.trechm.2021.05.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Cation-coupled chloride cotransporters (CCCs) modulate the transport of sodium and/or potassium cations coupled with chloride anions across the cell membrane. CCCs thus help regulate intracellular ionic concentration and consequent cell volume homeostasis. This has been largely exploited in the past to develop diuretic drugs that act on CCCs expressed in the kidney. However, a growing wealth of evidence has demonstrated that CCCs are also critically involved in a great variety of other pathologies, motivating most recent drug discovery programs targeting CCCs. Here, we examine the structure–function relationship of CCCs. By linking recent high-resolution cryogenic electron microscopy (cryo-EM) data with older biochemical/functional studies on CCCs, we discuss the mechanistic insights and opportunities to design selective CCC modulators to treat diverse pathologies. The structural topology and function of all cation-coupled chloride cotransporters (CCCs) have been continuously investigated over the past 40 years, with great progress also thanks to the recent cryogenic electron microscopy (cryo-EM) resolution of the structures of five CCCs. In particular, such studies have clarified the structure–function relationship for the Na-K-Cl cotransporter NKCC1 and K-Cl cotransporters KCC1–4. The constantly growing evidence of the crucial involvement of CCCs in physiological and various pathological conditions, as well as the evidence of their wide expression in diverse body tissues, has promoted CCCs as targets for the discovery and development of new, safer, and more selective/effective drugs for a plethora of pathologies. Post-translational modification anchor points on the structure of CCCs may offer alternative strategies for small molecule drug discovery.
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Affiliation(s)
- Corinne Portioli
- Brain Development and Disease Laboratory, Istituto Italiano di Tecnologia (IIT), Via Morego 30, 16163 Genoa, Italy.,Laboratory of Molecular Modeling and Drug Discovery, IIT, Via Morego, 30 16163 Genoa, Italy
| | | | - Marco De Vivo
- Laboratory of Molecular Modeling and Drug Discovery, IIT, Via Morego, 30 16163 Genoa, Italy
| | - Laura Cancedda
- Brain Development and Disease Laboratory, Istituto Italiano di Tecnologia (IIT), Via Morego 30, 16163 Genoa, Italy.,Dulbecco Telethon Institute, Via Varese 16b, 00185 Rome, Italy
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23
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Kortenoeven MLA, Esteva-Font C, Dimke H, Poulsen SB, Murali SK, Fenton RA. High dietary potassium causes ubiquitin-dependent degradation of the kidney sodium-chloride cotransporter. J Biol Chem 2021; 297:100915. [PMID: 34174287 PMCID: PMC8318901 DOI: 10.1016/j.jbc.2021.100915] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 06/10/2021] [Accepted: 06/22/2021] [Indexed: 11/24/2022] Open
Abstract
The thiazide-sensitive sodium-chloride cotransporter (NCC) in the renal distal convoluted tubule (DCT) plays a critical role in regulating blood pressure (BP) and K+ homeostasis. During hyperkalemia, reduced NCC phosphorylation and total NCC abundance facilitate downstream electrogenic K+ secretion and BP reduction. However, the mechanism for the K+-dependent reduction in total NCC levels is unknown. Here, we show that NCC levels were reduced in ex vivo renal tubules incubated in a high-K+ medium for 24–48 h. This reduction was independent of NCC transcription, but was prevented using inhibitors of the proteasome (MG132) or lysosome (chloroquine). Ex vivo, high K+ increased NCC ubiquitylation, but inhibition of the ubiquitin conjugation pathway prevented the high K+-mediated reduction in NCC protein. In tubules incubated in high K+ media ex vivo or in the renal cortex of mice fed a high K+ diet for 4 days, the abundance and phosphorylation of heat shock protein 70 (Hsp70), a key regulator of ubiquitin-dependent protein degradation and protein folding, were decreased. Conversely, in similar samples the expression of PP1α, known to dephosphorylate Hsp70, was also increased. NCC coimmunoprecipitated with Hsp70 and PP1α, and inhibiting their actions prevented the high K+-mediated reduction in total NCC levels. In conclusion, we show that hyperkalemia drives NCC ubiquitylation and degradation via a PP1α-dependent process facilitated by Hsp70. This mechanism facilitates K+-dependent reductions in NCC to protect plasma K+ homeostasis and potentially reduces BP.
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Affiliation(s)
- Marleen L A Kortenoeven
- Department of Biomedicine, Faculty of Health Sciences, Aarhus University, Aarhus, Denmark; Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark.
| | - Cristina Esteva-Font
- Department of Biomedicine, Faculty of Health Sciences, Aarhus University, Aarhus, Denmark
| | - Henrik Dimke
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark; Department of Nephrology, Odense University Hospital, Odense, Denmark
| | - Søren B Poulsen
- Department of Biomedicine, Faculty of Health Sciences, Aarhus University, Aarhus, Denmark
| | - Sathish K Murali
- Department of Biomedicine, Faculty of Health Sciences, Aarhus University, Aarhus, Denmark
| | - Robert A Fenton
- Department of Biomedicine, Faculty of Health Sciences, Aarhus University, Aarhus, Denmark.
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Olde Hanhof CJA, Yousef Yengej FA, Rookmaaker MB, Verhaar MC, van der Wijst J, Hoenderop JG. Modeling Distal Convoluted Tubule (Patho)Physiology: An Overview of Past Developments and an Outlook Toward the Future. Tissue Eng Part C Methods 2021; 27:200-212. [PMID: 33544049 DOI: 10.1089/ten.tec.2020.0345] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The kidneys are essential for maintaining electrolyte homeostasis. Blood electrolyte composition is controlled by active reabsorption and secretion processes in dedicated segments of the kidney tubule. Specifically, the distal convoluted tubule (DCT) and connecting tubule are important for regulating the final excretion of sodium, magnesium, and calcium. Studies unravelling the specific function of these segments have greatly improved our understanding of DCT (patho)physiology. Over the years, experimental models used to study the DCT have changed and the field has advanced from early dissection studies with rats and rabbits to the use of various transgenic mouse models. Developments in dissection techniques and cell culture methods have resulted in immortalized mouse DCT cell lines and made it possible to specifically obtain DCT fragments for ex vivo studies. However, we still do not fully understand the complex (patho)physiology of this segment and there is need for advanced human DCT models. Recently, kidney organoids and tubuloids have emerged as new complex cell models that provide excellent opportunities for physiological studies, disease modeling, drug discovery, and even personalized medicine in the future. This review presents an overview of cell models used to study the DCT and provides an outlook on kidney organoids and tubuloids as model for DCT (patho)physiology. Impact statement This study provides a detailed overview of past and future developments on cell models used to study kidney (patho)physiology and specifically the distal convoluted tubule (DCT) segment. Hereby, we highlight the need for an advanced human cell model of this segment and summarize recent advances in the field of kidney organoids and tubuloids with a focus on DCT properties. The findings reported in this review are significant for future developments toward an advanced human model of the DCT that will help to increase our understanding of DCT (patho)physiology.
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Affiliation(s)
- Charlotte J A Olde Hanhof
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Fjodor A Yousef Yengej
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences, Utrecht, The Netherlands.,Department of Nephrology and Hypertension, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Maarten B Rookmaaker
- Department of Nephrology and Hypertension, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Marianne C Verhaar
- Department of Nephrology and Hypertension, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Jenny van der Wijst
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Joost G Hoenderop
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
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25
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Franken GAC, Adella A, Bindels RJM, de Baaij JHF. Mechanisms coupling sodium and magnesium reabsorption in the distal convoluted tubule of the kidney. Acta Physiol (Oxf) 2021; 231:e13528. [PMID: 32603001 PMCID: PMC7816272 DOI: 10.1111/apha.13528] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 05/29/2020] [Accepted: 06/22/2020] [Indexed: 02/06/2023]
Abstract
Hypomagnesaemia is a common feature of renal Na+ wasting disorders such as Gitelman and EAST/SeSAME syndrome. These genetic defects specifically affect Na+ reabsorption in the distal convoluted tubule, where Mg2+ reabsorption is tightly regulated. Apical uptake via TRPM6 Mg2+ channels and basolateral Mg2+ extrusion via a putative Na+ -Mg2+ exchanger determines Mg2+ reabsorption in the distal convoluted tubule. However, the mechanisms that explain the high incidence of hypomagnesaemia in patients with Na+ wasting disorders of the distal convoluted tubule are largely unknown. In this review, we describe three potential mechanisms by which Mg2+ reabsorption in the distal convoluted tubule is linked to Na+ reabsorption. First, decreased activity of the thiazide-sensitive Na+ /Cl- cotransporter (NCC) results in shortening of the segment, reducing the Mg2+ reabsorption capacity. Second, the activity of TRPM6 and NCC are determined by common regulatory pathways. Secondary effects of NCC dysregulation such as hormonal imbalance, therefore, might disturb TRPM6 expression. Third, the basolateral membrane potential, maintained by the K+ permeability and Na+ -K+ -ATPase activity, provides the driving force for Na+ and Mg2+ extrusion. Depolarisation of the basolateral membrane potential in Na+ wasting disorders of the distal convoluted tubule may therefore lead to reduced activity of the putative Na+ -Mg2+ exchanger SLC41A1. Elucidating the interconnections between Mg2+ and Na+ transport in the distal convoluted tubule is hampered by the currently available models. Our analysis indicates that the coupling of Na+ and Mg2+ reabsorption may be multifactorial and that advanced experimental models are required to study the molecular mechanisms.
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Affiliation(s)
- Gijs A. C. Franken
- Department of PhysiologyRadboud Institute for Molecular Life SciencesRadboud University Medical CenterNijmegenthe Netherlands
| | - Anastasia Adella
- Department of PhysiologyRadboud Institute for Molecular Life SciencesRadboud University Medical CenterNijmegenthe Netherlands
| | - René J. M. Bindels
- Department of PhysiologyRadboud Institute for Molecular Life SciencesRadboud University Medical CenterNijmegenthe Netherlands
| | - Jeroen H. F. de Baaij
- Department of PhysiologyRadboud Institute for Molecular Life SciencesRadboud University Medical CenterNijmegenthe Netherlands
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26
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Ayuzawa N, Fujita T. The Mineralocorticoid Receptor in Salt-Sensitive Hypertension and Renal Injury. J Am Soc Nephrol 2021; 32:279-289. [PMID: 33397690 PMCID: PMC8054893 DOI: 10.1681/asn.2020071041] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Hypertension and its comorbidities pose a major public health problem associated with disease-associated factors related to a modern lifestyle, such high salt intake or obesity. Accumulating evidence has demonstrated that aldosterone and its receptor, the mineralocorticoid receptor (MR), have crucial roles in the development of salt-sensitive hypertension and coexisting cardiovascular and renal injuries. Accordingly, clinical trials have repetitively shown the promising effects of MR blockers in these diseases. We and other researchers have identified novel mechanisms of MR activation involved in salt-sensitive hypertension and renal injury, including the obesity-derived overproduction of aldosterone and ligand-independent signaling. Moreover, recent advances in the analysis of cell-specific and context-dependent mechanisms of MR activation in various tissues-including a classic target of aldosterone, aldosterone-sensitive distal nephrons-are now providing new insights. In this review, we summarize recent updates to our understanding of aldosterone-MR signaling, focusing on its role in salt-sensitive hypertension and renal injury.
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Affiliation(s)
- Nobuhiro Ayuzawa
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Toshiro Fujita
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan,Shinshu University School of Medicine, Nagano, Japan,Research Center for Social Systems, Shinshu University, Nagano, Japan
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27
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Magnesium and Calcium Homeostasis Depend on KCTD1 Function in the Distal Nephron. Cell Rep 2021; 34:108616. [PMID: 33440155 PMCID: PMC7869691 DOI: 10.1016/j.celrep.2020.108616] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 10/31/2020] [Accepted: 12/17/2020] [Indexed: 11/20/2022] Open
Abstract
Magnesium (Mg2+) homeostasis depends on active transcellular Mg2+ reuptake from urine in distal convoluted tubules (DCTs) via the Mg2+ channel TRPM6, whose activity has been proposed to be regulated by EGF. Calcium (Ca2+) homeostasis depends on paracellular reabsorption in the thick ascending limbs of Henle (TALs). KCTD1 promotes terminal differentiation of TALs/DCTs, but how its deficiency affects urinary Mg2+ and Ca2+ reabsorption is unknown. Here, this study shows that DCT1-specific KCTD1 inactivation leads to hypomagnesemia despite normal TRPM6 levels because of reduced levels of the sodium chloride co-transporter NCC, whereas Mg2+ homeostasis does not depend on EGF. Moreover, KCTD1 deficiency impairs paracellular urinary Ca2+ and Mg2+ reabsorption in TALs because of reduced NKCC2/claudin-16/-19 and increased claudin-14 expression, leading to hypocalcemia and consequently to secondary hyperparathyroidism and progressive metabolic bone disease. Thus, KCTD1 regulates urinary reabsorption of Mg2+ and Ca2+ by inducing expression of NCC in DCTs and NKCC2/claudin-16/-19 in TALs.
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28
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Ito A, Zhao Q, Tanaka Y, Yasui M, Katayama R, Sun S, Tanimoto Y, Nishikawa Y, Kage-Nakadai E. Metolazone upregulates mitochondrial chaperones and extends lifespan in Caenorhabditis elegans. Biogerontology 2020; 22:119-131. [PMID: 33216250 DOI: 10.1007/s10522-020-09907-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 11/11/2020] [Indexed: 01/01/2023]
Abstract
Accumulating studies have argued that the mitochondrial unfolded protein response (UPRmt) is a mitochondrial stress response that promotes longevity in model organisms. In the present study, we screened an off-patent drug library to identify compounds that activate UPRmt using a mitochondrial chaperone hsp-6::GFP reporter system in Caenorhabditis elegans. Metolazone, a diuretic primarily used to treat congestive heart failure and high blood pressure, was identified as a prominent hit as it upregulated hsp-6::GFP and not the endoplasmic reticulum chaperone hsp-4::GFP. Furthermore, metolazone specifically induced the expression of mitochondrial chaperones in the HeLa cell line. Metolazone also extended the lifespan of worms in a atfs-1 and ubl-5-dependent manner. Notably, metolazone failed to increase lifespan in worms with knocked-down nkcc-1. These results suggested that metolazone activates the UPRmt across species and prolongs the lifespan of C. elegans.
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Affiliation(s)
- Ai Ito
- Faculty of Human Life Science, Department of Food and Nutrition, Osaka City University, Sugimoto 3-3-138 Sumiyoshi-ku, Osaka, 558-8585, Japan
| | - Quichi Zhao
- Faculty of Human Life Science, Department of Food and Nutrition, Osaka City University, Sugimoto 3-3-138 Sumiyoshi-ku, Osaka, 558-8585, Japan
| | - Yoichiro Tanaka
- Faculty of Human Life Science, Department of Food and Nutrition, Osaka City University, Sugimoto 3-3-138 Sumiyoshi-ku, Osaka, 558-8585, Japan
| | - Masumi Yasui
- Faculty of Human Life Science, Department of Food and Nutrition, Osaka City University, Sugimoto 3-3-138 Sumiyoshi-ku, Osaka, 558-8585, Japan
| | - Rina Katayama
- Faculty of Human Life Science, Department of Food and Nutrition, Osaka City University, Sugimoto 3-3-138 Sumiyoshi-ku, Osaka, 558-8585, Japan
| | - Simo Sun
- Faculty of Human Life Science, Department of Food and Nutrition, Osaka City University, Sugimoto 3-3-138 Sumiyoshi-ku, Osaka, 558-8585, Japan
| | - Yoshihiko Tanimoto
- Faculty of Human Life Science, Department of Food and Nutrition, Osaka City University, Sugimoto 3-3-138 Sumiyoshi-ku, Osaka, 558-8585, Japan
| | - Yoshikazu Nishikawa
- Faculty of Human Life Science, Department of Food and Nutrition, Osaka City University, Sugimoto 3-3-138 Sumiyoshi-ku, Osaka, 558-8585, Japan
| | - Eriko Kage-Nakadai
- Faculty of Human Life Science, Department of Food and Nutrition, Osaka City University, Sugimoto 3-3-138 Sumiyoshi-ku, Osaka, 558-8585, Japan.
- The OCU Advanced Research Institute for Natural Science and Technology, Osaka City University, Osaka, 558-8585, Japan.
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29
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Deletion of the transcription factor Prox-1 specifically in the renal distal convoluted tubule causes hypomagnesemia via reduced expression of TRPM6 and NCC. Pflugers Arch 2020; 473:79-93. [PMID: 33200256 PMCID: PMC7782375 DOI: 10.1007/s00424-020-02491-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 10/25/2020] [Accepted: 11/05/2020] [Indexed: 12/15/2022]
Abstract
The renal distal convoluted tubule (DCT) is critical for the fine-tuning of urinary ion excretion and the control of blood pressure. Ion transport along the DCT is tightly controlled by posttranscriptional mechanisms including a complex interplay of kinases, phosphatases, and ubiquitin ligases. Previous work identified the transcription factor Prox-1 as a gene significantly enriched in the DCT of adult mice. To test if Prox-1 contributes to the transcriptional regulation of DCT function and structure, we developed a novel mouse model (NCCcre:Prox-1flox/flox) for an inducible deletion of Prox-1 specifically in the DCT. The deletion of Prox-1 had no obvious impact on DCT structure and growth independent whether the deletion was achieved in newborn or adult mice. Furthermore, DCT-specific Prox-1 deficiency did not alter DCT-proliferation in response to loop diuretic treatment. Likewise, the DCT-specific deletion of Prox-1 did not cause other gross phenotypic abnormalities. Body weight, urinary volume, Na+ and K+ excretion as well as plasma Na+, K+, and aldosterone levels were similar in Prox-1DCTKO and Prox-1DCTCtrl mice. However, Prox-1DCTKO mice exhibited a significant hypomagnesemia with a profound downregulation of the DCT-specific apical Mg2+ channel TRPM6 and the NaCl cotransporter (NCC) at both mRNA and protein levels. The expression of other proteins involved in distal tubule Mg2+ and Na+ handling was not affected. Thus, Prox-1 is a DCT-enriched transcription factor that does not control DCT growth but contributes to the molecular control of DCT-dependent Mg2+ homeostasis in the adult kidney.
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30
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Murillo-de-Ozores AR, Chávez-Canales M, de los Heros P, Gamba G, Castañeda-Bueno M. Physiological Processes Modulated by the Chloride-Sensitive WNK-SPAK/OSR1 Kinase Signaling Pathway and the Cation-Coupled Chloride Cotransporters. Front Physiol 2020; 11:585907. [PMID: 33192599 PMCID: PMC7606576 DOI: 10.3389/fphys.2020.585907] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 09/29/2020] [Indexed: 12/15/2022] Open
Abstract
The role of Cl- as an intracellular signaling ion has been increasingly recognized in recent years. One of the currently best described roles of Cl- in signaling is the modulation of the With-No-Lysine (K) (WNK) - STE20-Proline Alanine rich Kinase (SPAK)/Oxidative Stress Responsive Kinase 1 (OSR1) - Cation-Coupled Cl- Cotransporters (CCCs) cascade. Binding of a Cl- anion to the active site of WNK kinases directly modulates their activity, promoting their inhibition. WNK activation due to Cl- release from the binding site leads to phosphorylation and activation of SPAK/OSR1, which in turn phosphorylate the CCCs. Phosphorylation by WNKs-SPAK/OSR1 of the Na+-driven CCCs (mediating ions influx) promote their activation, whereas that of the K+-driven CCCs (mediating ions efflux) promote their inhibition. This results in net Cl- influx and feedback inhibition of WNK kinases. A wide variety of alterations to this pathway have been recognized as the cause of several human diseases, with manifestations in different systems. The understanding of WNK kinases as Cl- sensitive proteins has allowed us to better understand the mechanistic details of regulatory processes involved in diverse physiological phenomena that are reviewed here. These include cell volume regulation, potassium sensing and intracellular signaling in the renal distal convoluted tubule, and regulation of the neuronal response to the neurotransmitter GABA.
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Affiliation(s)
- Adrián Rafael Murillo-de-Ozores
- Department of Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
- Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - María Chávez-Canales
- Unidad de Investigación UNAM-INC, Instituto Nacional de Cardiología Ignacio Chávez and Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Paola de los Heros
- Unidad de Investigación UNAM-INC, Research Division, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Gerardo Gamba
- Department of Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
- Molecular Physiology Unit, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - María Castañeda-Bueno
- Department of Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
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31
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The sodium/proton exchanger NHA2 regulates blood pressure through a WNK4-NCC dependent pathway in the kidney. Kidney Int 2020; 99:350-363. [PMID: 32956652 DOI: 10.1016/j.kint.2020.08.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 08/13/2020] [Accepted: 08/26/2020] [Indexed: 02/07/2023]
Abstract
NHA2 is a sodium/proton exchanger associated with arterial hypertension in humans, but the role of NHA2 in kidney function and blood pressure homeostasis is currently unknown. Here we show that NHA2 localizes almost exclusively to distal convoluted tubules in the kidney. NHA2 knock-out mice displayed reduced blood pressure, normocalcemic hypocalciuria and an attenuated response to the thiazide diuretic hydrochlorothiazide. Phosphorylation of the thiazide-sensitive sodium/chloride cotransporter NCC and its upstream activating kinase Ste20/SPS1-related proline/alanine rich kinase (SPAK), as well as the abundance of with no lysine kinase 4 (WNK4), were significantly reduced in the kidneys of NHA2 knock-out mice. In vitro experiments recapitulated these findings and revealed increased WNK4 ubiquitylation and enhanced proteasomal WNK4 degradation upon loss of NHA2. The effect of NHA2 on WNK4 stability was dependent from the ubiquitylation pathway protein Kelch-like 3 (KLHL3). More specifically, loss of NHA2 selectively attenuated KLHL3 phosphorylation and blunted protein kinase A- and protein kinase C-mediated decrease of WNK4 degradation. Phenotype analysis of NHA2/NCC double knock-out mice supported the notion that NHA2 affects blood pressure homeostasis by a kidney-specific and NCC-dependent mechanism. Thus, our data show that NHA2 as a critical component of the WNK4-NCC pathway and is a novel regulator of blood pressure homeostasis in the kidney.
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32
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Wall SM, Verlander JW, Romero CA. The Renal Physiology of Pendrin-Positive Intercalated Cells. Physiol Rev 2020; 100:1119-1147. [PMID: 32347156 PMCID: PMC7474261 DOI: 10.1152/physrev.00011.2019] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 11/06/2019] [Accepted: 11/12/2019] [Indexed: 12/13/2022] Open
Abstract
Intercalated cells (ICs) are found in the connecting tubule and the collecting duct. Of the three IC subtypes identified, type B intercalated cells are one of the best characterized and known to mediate Cl- absorption and HCO3- secretion, largely through the anion exchanger pendrin. This exchanger is thought to act in tandem with the Na+-dependent Cl-/HCO3- exchanger, NDCBE, to mediate net NaCl absorption. Pendrin is stimulated by angiotensin II and aldosterone administration via the angiotensin type 1a and the mineralocorticoid receptors, respectively. It is also stimulated in models of metabolic alkalosis, such as with NaHCO3 administration. In some rodent models, pendrin-mediated HCO3- secretion modulates acid-base balance. However, of probably more physiological or clinical significance is the role of these pendrin-positive ICs in blood pressure regulation, which occurs, at least in part, through pendrin-mediated renal Cl- absorption, as well as their effect on the epithelial Na+ channel, ENaC. Aldosterone stimulates ENaC directly through principal cell mineralocorticoid hormone receptor (ligand) binding and also indirectly through its effect on pendrin expression and function. In so doing, pendrin contributes to the aldosterone pressor response. Pendrin may also modulate blood pressure in part through its action in the adrenal medulla, where it modulates the release of catecholamines, or through an indirect effect on vascular contractile force. In addition to its role in Na+ and Cl- balance, pendrin affects the balance of other ions, such as K+ and I-. This review describes how aldosterone and angiotensin II-induced signaling regulate pendrin and the contribution of pendrin-positive ICs in the kidney to distal nephron function and blood pressure.
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Affiliation(s)
- Susan M Wall
- Departments of Medicine and Physiology, Emory University School of Medicine, Atlanta, Georgia; and Department of Medicine, University of Florida, Gainesville, Florida
| | - Jill W Verlander
- Departments of Medicine and Physiology, Emory University School of Medicine, Atlanta, Georgia; and Department of Medicine, University of Florida, Gainesville, Florida
| | - Cesar A Romero
- Departments of Medicine and Physiology, Emory University School of Medicine, Atlanta, Georgia; and Department of Medicine, University of Florida, Gainesville, Florida
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33
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Ayuzawa N, Nishimoto M, Ueda K, Hirohama D, Kawarazaki W, Shimosawa T, Marumo T, Fujita T. Two Mineralocorticoid Receptor-Mediated Mechanisms of Pendrin Activation in Distal Nephrons. J Am Soc Nephrol 2020; 31:748-764. [PMID: 32034107 DOI: 10.1681/asn.2019080804] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 12/27/2019] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Regulation of sodium chloride transport in the aldosterone-sensitive distal nephron is essential for fluid homeostasis and BP control. The chloride-bicarbonate exchanger pendrin in β-intercalated cells, along with sodium chloride cotransporter (NCC) in distal convoluted tubules, complementarily regulate sodium chloride handling, which is controlled by the renin-angiotensin-aldosterone system. METHODS Using mice with mineralocorticoid receptor deletion in intercalated cells, we examined the mechanism and roles of pendrin upregulation via mineralocorticoid receptor in two different models of renin-angiotensin-aldosterone system activation. We also used aldosterone-treated NCC knockout mice to examine the role of pendrin regulation in salt-sensitive hypertension. RESULTS Deletion of mineralocorticoid receptor in intercalated cells suppressed the increase in renal pendrin expression induced by either exogenous angiotensin II infusion or endogenous angiotensin II upregulation via salt restriction. When fed a low-salt diet, intercalated cell-specific mineralocorticoid receptor knockout mice with suppression of pendrin upregulation showed BP reduction that was attenuated by compensatory activation of NCC. In contrast, upregulation of pendrin induced by aldosterone excess combined with a high-salt diet was scarcely affected by deletion of mineralocorticoid receptor in intercalated cells, but depended instead on hypokalemic alkalosis through the activated mineralocorticoid receptor-epithelial sodium channel cascade in principal cells. In aldosterone-treated NCC knockout mice showing upregulation of pendrin, potassium supplementation corrected alkalosis and inhibited the pendrin upregulation, thereby lowering BP. CONCLUSIONS In conjunction with NCC, the two pathways of pendrin upregulation, induced by angiotensin II through mineralocorticoid receptor activation in intercalated cells and by alkalosis through mineralocorticoid receptor activation in principal cells, play important roles in fluid homeostasis during salt depletion and salt-sensitive hypertension mediated by aldosterone excess.
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Affiliation(s)
- Nobuhiro Ayuzawa
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan;
| | - Mitsuhiro Nishimoto
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Kohei Ueda
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Daigoro Hirohama
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Wakako Kawarazaki
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Tatsuo Shimosawa
- Department of Clinical Laboratory, School of Medicine, International University of Health and Welfare, Chiba, Japan
| | - Takeshi Marumo
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Toshiro Fujita
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan;
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34
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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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Mabillard H, Sayer JA. The Molecular Genetics of Gordon Syndrome. Genes (Basel) 2019; 10:genes10120986. [PMID: 31795491 PMCID: PMC6947027 DOI: 10.3390/genes10120986] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 11/22/2019] [Accepted: 11/25/2019] [Indexed: 12/12/2022] Open
Abstract
Gordon syndrome is a rare inherited monogenic form of hypertension, which is associated with hyperkalaemia and metabolic acidosis. Since the recognition of this predominantly autosomal dominant condition in the 1960s, the study of families with Gordon syndrome has revealed four genes WNK1, WNK4, KLHL3, and CUL3 to be implicated in its pathogenesis after a phenotype–genotype correlation was realised. The encoded proteins Kelch-like 3 and Cullin 3 interact to form a ring-like complex to ubiquitinate WNK-kinase 4, which, in normal circumstances, interacts with the sodium chloride co-symporter (NCC), the epithelial sodium channel (ENaC), and the renal outer medullary potassium channel (ROMK) in an inhibitory manner to maintain normokalaemia and normotension. WNK-kinase 1 has an inhibitory action on WNK-kinase 4. Mutations in WNK1, WNK4, KLHL3, and CUL3 all result in the accumulation of WNK-kinase 4 and subsequent hypertension, hyperkalaemia, and metabolic acidosis. This review explains the clinical aspects, disease mechanisms, and molecular genetics of Gordon syndrome.
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Affiliation(s)
- Holly Mabillard
- Renal Services, The Newcastle Hospitals NHS Foundation Trust, Newcastle upon Tyne NE7 7DN, UK;
| | - John A. Sayer
- Renal Services, The Newcastle Hospitals NHS Foundation Trust, Newcastle upon Tyne NE7 7DN, UK;
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Institute of Genetic Medicine, Newcastle University, International Centre for Life, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK
- NIHR Newcastle Biomedical Research Centre, Newcastle University, Newcastle upon Tyne NE4 5PL, UK
- Correspondence: ; Tel.: +44-191-2418608
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Lerman LO, Kurtz TW, Touyz RM, Ellison DH, Chade AR, Crowley SD, Mattson DL, Mullins JJ, Osborn J, Eirin A, Reckelhoff JF, Iadecola C, Coffman TM. Animal Models of Hypertension: A Scientific Statement From the American Heart Association. Hypertension 2019; 73:e87-e120. [PMID: 30866654 DOI: 10.1161/hyp.0000000000000090] [Citation(s) in RCA: 171] [Impact Index Per Article: 34.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Hypertension is the most common chronic disease in the world, yet the precise cause of elevated blood pressure often cannot be determined. Animal models have been useful for unraveling the pathogenesis of hypertension and for testing novel therapeutic strategies. The utility of animal models for improving the understanding of the pathogenesis, prevention, and treatment of hypertension and its comorbidities depends on their validity for representing human forms of hypertension, including responses to therapy, and on the quality of studies in those models (such as reproducibility and experimental design). Important unmet needs in this field include the development of models that mimic the discrete hypertensive syndromes that now populate the clinic, resolution of ongoing controversies in the pathogenesis of hypertension, and the development of new avenues for preventing and treating hypertension and its complications. Animal models may indeed be useful for addressing these unmet needs.
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Ferdaus MZ, Mukherjee A, Nelson JW, Blatt PJ, Miller LN, Terker AS, Staub O, Lin DH, McCormick JA. Mg 2+ restriction downregulates NCC through NEDD4-2 and prevents its activation by hypokalemia. Am J Physiol Renal Physiol 2019; 317:F825-F838. [PMID: 31364380 PMCID: PMC6843039 DOI: 10.1152/ajprenal.00216.2019] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Hypomagnesemia is associated with reduced kidney function and life-threatening complications and sustains hypokalemia. The distal convoluted tubule (DCT) determines final urinary Mg2+ excretion and, via activity of the Na+-Cl- cotransporter (NCC), also plays a key role in K+ homeostasis by metering Na+ delivery to distal segments. Little is known about the mechanisms by which plasma Mg2+ concentration regulates NCC activity and how low-plasma Mg2+ concentration and K+ concentration interact to modulate NCC activity. To address this, we performed dietary manipulation studies in mice. Compared with normal diet, abundances of total NCC and phosphorylated NCC (pNCC) were lower after short-term (3 days) or long-term (14 days) dietary Mg2+ restriction. Altered NCC activation is unlikely to play a role, since we also observed lower total NCC abundance in mice lacking the two NCC-activating kinases, STE20/SPS-1-related proline/alanine-rich kinase and oxidative stress response kinase-1, after Mg2+ restriction. The E3 ubiquitin-protein ligase NEDD4-2 regulates NCC abundance during dietary NaCl loading or K+ restriction. Mg2+ restriction did not lower total NCC abundance in inducible nephron-specific neuronal precursor cell developmentally downregulated 4-2 (NEDD4-2) knockout mice. Total NCC and pNCC abundances were similar after short-term Mg2+ or combined Mg2+-K+ restriction but were dramatically lower compared with a low-K+ diet. Therefore, sustained NCC downregulation may serve a mechanism that enhances distal Na+ delivery during states of hypomagnesemia, maintaining hypokalemia. Similar results were obtained with long-term Mg2+-K+ restriction, but, surprisingly, NCC was not activated after long-term K+ restriction despite lower plasma K+ concentration, suggesting significant differences in distal tubule adaptation to acute or chronic K+ restriction.
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Affiliation(s)
- Mohammed Z. Ferdaus
- 1Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon
| | - Anindit Mukherjee
- 1Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon
| | - Jonathan W. Nelson
- 1Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon
| | - Philip J. Blatt
- 1Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon
| | - Lauren N. Miller
- 1Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon
| | - Andrew S. Terker
- 2Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Olivier Staub
- 3Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland
| | - Dao-Hong Lin
- 4Department of Pharmacology, New York Medical College, Valhalla, New York
| | - James A. McCormick
- 1Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon
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van der Wijst J, Belge H, Bindels RJM, Devuyst O. Learning Physiology From Inherited Kidney Disorders. Physiol Rev 2019; 99:1575-1653. [PMID: 31215303 DOI: 10.1152/physrev.00008.2018] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The identification of genes causing inherited kidney diseases yielded crucial insights in the molecular basis of disease and improved our understanding of physiological processes that operate in the kidney. Monogenic kidney disorders are caused by mutations in genes coding for a large variety of proteins including receptors, channels and transporters, enzymes, transcription factors, and structural components, operating in specialized cell types that perform highly regulated homeostatic functions. Common variants in some of these genes are also associated with complex traits, as evidenced by genome-wide association studies in the general population. In this review, we discuss how the molecular genetics of inherited disorders affecting different tubular segments of the nephron improved our understanding of various transport processes and of their involvement in homeostasis, while providing novel therapeutic targets. These include inherited disorders causing a dysfunction of the proximal tubule (renal Fanconi syndrome), with emphasis on epithelial differentiation and receptor-mediated endocytosis, or affecting the reabsorption of glucose, the handling of uric acid, and the reabsorption of sodium, calcium, and magnesium along the kidney tubule.
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Affiliation(s)
- Jenny van der Wijst
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center , Nijmegen , The Netherlands ; Institute of Physiology, University of Zurich , Zurich , Switzerland ; and Division of Nephrology, Institute of Experimental and Clinical Research (IREC), Medical School, Université catholique de Louvain, Brussels, Belgium
| | - Hendrica Belge
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center , Nijmegen , The Netherlands ; Institute of Physiology, University of Zurich , Zurich , Switzerland ; and Division of Nephrology, Institute of Experimental and Clinical Research (IREC), Medical School, Université catholique de Louvain, Brussels, Belgium
| | - René J M Bindels
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center , Nijmegen , The Netherlands ; Institute of Physiology, University of Zurich , Zurich , Switzerland ; and Division of Nephrology, Institute of Experimental and Clinical Research (IREC), Medical School, Université catholique de Louvain, Brussels, Belgium
| | - Olivier Devuyst
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center , Nijmegen , The Netherlands ; Institute of Physiology, University of Zurich , Zurich , Switzerland ; and Division of Nephrology, Institute of Experimental and Clinical Research (IREC), Medical School, Université catholique de Louvain, Brussels, Belgium
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Rapoport RM, Soleimani M. Mechanism of Thiazide Diuretic Arterial Pressure Reduction: The Search Continues. Front Pharmacol 2019; 10:815. [PMID: 31543812 PMCID: PMC6730501 DOI: 10.3389/fphar.2019.00815] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 06/24/2019] [Indexed: 12/21/2022] Open
Abstract
Thiazide diuretic (TZD)-mediated chronic reduction of arterial pressure is thought to occur through decreased total peripheral vascular resistance. Further, the decreased peripheral vascular resistance is accomplished through TZD activation of an extrarenal target, resulting in inhibition of vascular constriction. However, despite greater than five decades of investigation, little progress has been made into the identification of the TZD extrarenal target. Proposed mechanisms range from direct inhibition of constrictor and activation of relaxant signaling pathways in the vascular smooth muscle to indirect inhibition through decreased neurogenic and hormonal regulatory pathways. Surprisingly, particularly in view of this lack of progress, comprehensive reviews of the subject are absent. Moreover, even though it is well recognized that 1) several types of hypertension are insensitive to TZD reduction of arterial pressure and, further, TZD fail to reduce arterial pressure in normotensive subjects and animals, and 2) different mechanisms underlie acute and chronic TZD, findings derived from these models and parameters remain largely undifferentiated. This review 1) comprehensively describes findings associated with TZD reduction of arterial pressure; 2) differentiates between observations in TZD-sensitive and TZD-insensitive hypertension, normotensive subjects/animals, and acute and chronic effects of TZD; 3) critically evaluates proposed TZD extrarenal targets; 4) proposes guiding parameters for relevant investigations into extrarenal TZD target identification; and 5) proposes a working model for TZD chronic reduction of arterial pressure through vascular dilation.
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Affiliation(s)
- Robert M Rapoport
- Department of Pharmacology and Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, OH, United States
| | - Manoocher Soleimani
- Research Service, Veterans Affairs Medical Center, Cincinnati, OH, United States.,Department of Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, United States
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Schnoz C, Carrel M, Loffing J. Loss of sodium chloride co-transporter impairs the outgrowth of the renal distal convoluted tubule during renal development. Nephrol Dial Transplant 2019; 35:411-432. [DOI: 10.1093/ndt/gfz172] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 07/12/2019] [Indexed: 12/15/2022] Open
Abstract
Abstract
Background
Loss-of-function mutations in the sodium chloride (NaCl) co-transporter (NCC) of the renal distal convoluted tubule (DCT) cause Gitelman syndrome with hypokalemic alkalosis, hypomagnesemia and hypocalciuria. Since Gitelman patients are usually diagnosed around adolescence, we tested the idea that a progressive regression of the DCT explains the late clinical onset of the syndrome.
Methods
NCC wild-type and knockout (ko) mice were studied at Days 1, 4 and 10 and 6 weeks after birth using blood plasma analysis and morphological and biochemical methods.
Results
Plasma aldosterone levels and renal renin messenger RNA expression were elevated in NCC ko mice during the first days of life. In contrast, plasma ion levels did not differ between genotypes at age 10 days, but a significant hypomagnesemia was observed in NCC ko mice at 6 weeks. Immunofluorescent detection of parvalbumin (an early DCT marker) revealed that the fractional cortical volume of the early DCT is similar for mice of both genotypes at Day 4, but is significantly lower at Day 10 and is almost zero at 6 weeks in NCC ko mice. The DCT atrophy correlates with a marked reduction in the abundance of the DCT-specific Mg2+ channel TRPM6 (transient receptor potential cation channel subfamily M member 6) and an increased proteolytic activation of the epithelial Na+ channel (ENaC).
Conclusion
After an initial outgrowth, DCT development lags behind in NCC ko mice. The impaired DCT development associates at Day 1 and Day 10 with elevated renal renin and plasma aldosterone levels and activation of ENaC, respectively, suggesting that Gitelman syndrome might be present much earlier in life than is usually expected. Despite an early downregulation of TRPM6, hypomagnesemia is a rather late symptom.
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Affiliation(s)
| | - Monique Carrel
- Institute of Anatomy, University of Zurich, Zurich, Switzerland
| | - Johannes Loffing
- Institute of Anatomy, University of Zurich, Zurich, Switzerland
- National Centre of Competence in Research ‘Kidney.CH’, University of Zurich, Zurich, Switzerland
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Affiliation(s)
- David H Ellison
- Division of Nephrology and Hypertension, Departments of Medicine and Physiology and Pharmacology, Oregon Health and Science University, Portland, Oregon; .,Renal Section, VA Portland Health Care System, Portland, Oregon; and
| | - Shih-Hua Lin
- Division of Nephrology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
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Rodan AR. Intracellular chloride: a regulator of transepithelial transport in the distal nephron. Curr Opin Nephrol Hypertens 2019; 28:360-367. [PMID: 30865168 PMCID: PMC6684285 DOI: 10.1097/mnh.0000000000000502] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
PURPOSE OF REVIEW This review focuses on the role of intracellular chloride in regulating transepithelial ion transport in the distal convoluted tubule (DCT) in response to perturbations in plasma potassium homeostasis. RECENT FINDINGS Low dietary potassium increases the phosphorylation and activity of the sodium chloride cotransporter (NCC) in the DCT, and vice versa, affecting sodium-dependent potassium secretion in the downstream aldosterone-sensitive distal nephron. In cells, NCC phosphorylation is increased by lowering of intracellular chloride, via activation of the chloride-sensitive with no lysine (WNK)-SPAK/OSR1 (Ste20-related proline/alanine-rich kinase/oxidative stress response) kinase cascade. In-vivo studies have demonstrated pathway activation in the kidney in response to low dietary potassium. A possible mechanism is lowering of DCT intracellular chloride in response to low potassium because of parallel basolateral potassium and chloride channels. Recent studies support a role for these channels in the response of NCC to varying potassium. Studies examining chloride-insensitive WNK mutants, in the Drosophila renal tubule and in the mouse, lend further support to a role for chloride in regulating WNK activity and transepithelial ion transport. Caveats, alternatives, and future directions are also discussed. SUMMARY Chloride sensing by WNK kinase provides a mechanism to allow coupling of extracellular potassium with NCC phosphorylation and activity to maintain potassium homeostasis.
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Affiliation(s)
- Aylin R. Rodan
- Department of Internal Medicine, Division of Nephrology and Hypertension and Molecular Medicine Program, University of Utah, and Medical Service, Veterans Affairs Salt Lake City Health Care System, Salt Lake City, UT
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Huang H, Song S, Banerjee S, Jiang T, Zhang J, Kahle KT, Sun D, Zhang Z. The WNK-SPAK/OSR1 Kinases and the Cation-Chloride Cotransporters as Therapeutic Targets for Neurological Diseases. Aging Dis 2019; 10:626-636. [PMID: 31165006 PMCID: PMC6538211 DOI: 10.14336/ad.2018.0928] [Citation(s) in RCA: 30] [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: 08/19/2018] [Accepted: 09/28/2018] [Indexed: 02/05/2023] Open
Abstract
In recent years, cation-chloride cotransporters (CCCs) have drawn attention in the medical neuroscience research. CCCs include the family of Na+-coupled Cl- importers (NCC, NKCC1, and NKCC2), K+-coupled Cl- exporters (KCCs), and possibly polyamine transporters (CCC9) and CCC interacting protein (CIP1). For decades, CCCs have been the targets of several commonly used diuretic drugs, including hydrochlorothiazide, furosemide, and bumetanide. Genetic mutations of NCC and NKCC2 cause congenital renal tubular disorders and lead to renal salt-losing hypotension, secondary hyperreninemia, and hypokalemic metabolic alkalosis. New studies reveal that CCCs along with their regulatory WNK (Kinase with no lysine (K)), and SPAK (Ste20-related proline-alanine-rich kinase)/OSR1(oxidative stress-responsive kinase-1) are essential for regulating cell volume and maintaining ionic homeostasis in the nervous system, especially roles of the WNK-SPAK-NKCC1 signaling pathway in ischemic brain injury and hypersecretion of cerebrospinal fluid in post-hemorrhagic hydrocephalus. In addition, disruption of Cl- exporter KCC2 has an effect on synaptic inhibition, which may be involved in developing pain, epilepsy, and possibly some neuropsychiatric disorders. Interference with KCC3 leads to peripheral nervous system neuropathy as well as axon and nerve fiber swelling and psychosis. The WNK-SPAK/OSR1-CCCs complex emerges as therapeutic targets for multiple neurological diseases. This review will highlight these new findings.
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Affiliation(s)
- Huachen Huang
- Department of Neurology, The First Affiliate Hospital, Harbin Medical University, Harbin, Heilongjiang, China.
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA.
| | - Shanshan Song
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA.
| | - Suneel Banerjee
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA.
| | - Tong Jiang
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA.
| | - Jinwei Zhang
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Hatherly Laboratory, Exeter, EX4 4PS, UK.
| | - Kristopher T. Kahle
- Departments of Neurosurgery, Pediatrics, and Cellular & Molecular Physiology, Centers for Mendelian Genomics, Yale School of Medicine, New Haven, CT, USA.
| | - Dandan Sun
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA.
- Veterans Affairs Pittsburgh Health Care System, Geriatric Research, Education and Clinical Center, Pittsburgh, PA, USA.
- Correspondence should be addressed to: Dr. Dandan Sun, Department of Neurology, University of Pittsburgh, Pittsburgh, USA. . Dr. Zhongling Zhang, The First Affiliated Hospital, Harbin Medical University, China.
| | - Zhongling Zhang
- Department of Neurology, The First Affiliate Hospital, Harbin Medical University, Harbin, Heilongjiang, China.
- Correspondence should be addressed to: Dr. Dandan Sun, Department of Neurology, University of Pittsburgh, Pittsburgh, USA. . Dr. Zhongling Zhang, The First Affiliated Hospital, Harbin Medical University, China.
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Meurer M, Höcherl K. Deregulated renal magnesium transport during lipopolysaccharide-induced acute kidney injury in mice. Pflugers Arch 2019; 471:619-631. [PMID: 30726531 DOI: 10.1007/s00424-019-02261-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 01/13/2019] [Accepted: 01/24/2019] [Indexed: 02/06/2023]
Abstract
Magnesium (Mg2+) abnormalities during sepsis have been reported, but the underlying mechanisms during acute inflammation are poorly understood. We hypothesized that a decrease in GFR and/or changes in transporters or channels for Mg2+ could be responsible for the observed Mg2+ abnormalities. Therefore, we studied the metabolism of Mg2+ in a murine model of endotoxemia. LPS-induced hypermagnesemia was paralleled by a decrease in creatinine clearance and an increase in the fractional excretion of Mg2+. In agreement with an altered renal Mg2+ handling, endotoxemia decreased the renal expression of claudin (Cldn) 10b, Cldn16, Cldn19, parvalbumin, and of the solute carrier family (Slc) 41a3. Further, LPS increased the renal expression of Cldn14 and Slc41a1. The renal expression of the transient receptor potential melastin (Trpm) 6, Trpm7, and of cyclin M (Cnnm) 2 was unaltered in response to LPS. In vitro studies support a direct effect on the expression of Cldn10b, Cldn14, Cldn16, and Cldn19. Further, endotoxemia increased the fractional excretion of sodium, which was paralleled by a decrease of important renal sodium transporters. In the large intestine, the expression of Trpm7 was increased in response to LPS, whereas the expression of Trpm6 was decreased. Cnnm4 mRNA levels were unchanged in the large intestine. Further, Cldn12 and Na+-H+ exchanger 3 (Slc9a3) expressions were decreased in the small intestine in response to LPS. Our findings indicate that endotoxemia is associated with hypermagnesemia and a disturbed Mg2+ handling. It seems likely that LPS-induced hypermagnesemia is due to the decrease in renal function in response to LPS.
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Affiliation(s)
- Manuel Meurer
- Institute of Experimental and Clinical Pharmacology and Toxicology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Fahrstr. 17, 91054, Erlangen, Germany
| | - Klaus Höcherl
- Institute of Experimental and Clinical Pharmacology and Toxicology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Fahrstr. 17, 91054, Erlangen, Germany.
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Chen Q, Wu Y, Zhao J, Jia Y, Wang W. A case of hypokalemia and proteinuria with a new mutation in the SLC12A3 Gene. BMC Nephrol 2018; 19:275. [PMID: 30340552 PMCID: PMC6194551 DOI: 10.1186/s12882-018-1083-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 10/08/2018] [Indexed: 12/17/2022] Open
Abstract
Background Gitelman syndrome is an autosomal recessive inherited renal disorder characterized by hypokalemia, hypomagnesemia, and hypocalciuria. Since the symptoms are not severe and laboratory results are not always clear, Gitelman syndrome can go unnoticed by physicians. Here, we report our experiences with a patient that presented with hypokalemia and proteinuria; genetic analysis revealed a new homozygous mutation in the SLC12A3 gene. Case presentation A 47-year-old man presented with hypokalemia and proteinuria. He had come to the hospital with the same symptoms 11 months and 3 years prior. His laboratory tests showed hypokalemia, hypocalciuria, and increased plasma angiotensin-2 activity. His renal pathology was consistent with the development of minimal lesions. Genetic analysis found a new homozygous mutation in exon 6 on the SLC12A3 gene (p.Trp281Arg) in the patient and in his brother; his mother and sister were diagnosed as heterozygous carriers of the same gene mutation. Finally, the patient was diagnosed with Gitelman syndrome. Conclusions This case is the first to report a homozygous mutation in the 841th nucleotide of exon 6 on the SLC12A3 gene (p.Trp281Arg), which may cause Gitelman syndrome. At the same time, this report might stimulate interest in discussing the relationship between different mutations in the SLC12A3 gene and renal pathology.
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Affiliation(s)
- Qin Chen
- Department of Nephrology, Tongde Hospital of Zhejiang Province, Gucui Road, No.234, Hangzhou, 310012, Zhejiang, People's Republic of China.
| | - Yaqin Wu
- Department of Internal Medicine, Cixi Chinese Medical Hospital, Cixi, 315300, Zhejiang, People's Republic of China
| | - Jingya Zhao
- Zhejiang Chinese Medical University, Hangzhou, 310053, Zhejiang, People's Republic of China
| | - Ying Jia
- Zhejiang Chinese Medical University, Hangzhou, 310053, Zhejiang, People's Republic of China
| | - Wei Wang
- Department of Nephrology, Tongde Hospital of Zhejiang Province, Gucui Road, No.234, Hangzhou, 310012, Zhejiang, People's Republic of China
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Malik S, Lambert E, Zhang J, Wang T, Clark HL, Cypress M, Goldman BI, Porter GA, Pena S, Nino W, Gray DA. Potassium conservation is impaired in mice with reduced renal expression of Kir4.1. Am J Physiol Renal Physiol 2018; 315:F1271-F1282. [PMID: 30110571 DOI: 10.1152/ajprenal.00022.2018] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
To better understand the role of the inward-rectifying K channel Kir4.1 (KCNJ10) in the distal nephron, we initially studied a global Kir4.1 knockout mouse (gKO), which demonstrated the hypokalemia and hypomagnesemia seen in SeSAME/EAST syndrome and was associated with reduced Na/Cl cotransporter (NCC) expression. Lethality by ~3 wk, however, limits the usefulness of this model, so we developed a kidney-specific Kir4.1 "knockdown" mouse (ksKD) using a cadherin 16 promoter and Cre-loxP methodology. These mice appeared normal and survived to adulthood. Kir4.1 protein expression was decreased ~50% vs. wild-type (WT) mice by immunoblotting, and immunofluorescence showed moderately reduced Kir4.1 staining in distal convoluted tubule that was minimal or absent in connecting tubule and cortical collecting duct. Under control conditions, the ksKD mice showed metabolic alkalosis and relative hypercalcemia but were normokalemic and mildly hypermagnesemic despite decreased NCC expression. In addition, the mice had a severe urinary concentrating defect associated with hypernatremia, enlarged kidneys with tubulocystic dilations, and reduced aquaporin-3 expression. On a K/Mg-free diet for 1 wk, however, ksKD mice showed marked hypokalemia (serum K: 1.5 ± 0.1 vs. 3.0 ± 0.1 mEq/l for WT), which was associated with renal K wasting (transtubular K gradient: 11.4 ± 0.8 vs. 1.6 ± 0.4 in WT). Phosphorylated-NCC expression increased in WT but not ksKD mice on the K/Mg-free diet, suggesting that loss of NCC adaptation underlies the hypokalemia. In conclusion, even modest reduction in Kir4.1 expression results in impaired K conservation, which appears to be mediated by reduced expression of activated NCC.
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Affiliation(s)
- Sundeep Malik
- Department of Pharmacology and Physiology, School of Medicine, University of Rochester , Rochester, New York
| | - Emily Lambert
- Nephrology Division, Department of Medicine, University of Rochester , Rochester, New York
| | - Junhui Zhang
- Department of Cellular and Molecular Physiology, Yale University School of Medicine , New Haven, Connecticut
| | - Tong Wang
- Department of Cellular and Molecular Physiology, Yale University School of Medicine , New Haven, Connecticut
| | - Heather L Clark
- Nephrology Division, Department of Medicine, University of Rochester , Rochester, New York
| | - Michael Cypress
- Nephrology Division, Department of Medicine, University of Rochester , Rochester, New York
| | - Bruce I Goldman
- Pathology and Laboratory Medicine, University of Rochester , Rochester, New York
| | - George A Porter
- Cardiology Division, Department of Pediatrics, University of Rochester , Rochester, New York
| | - Salvador Pena
- Nephrology Division, Department of Medicine, University of Rochester , Rochester, New York
| | - Wilson Nino
- Nephrology Division, Department of Medicine, University of Rochester , Rochester, New York
| | - Daniel A Gray
- Nephrology Division, Department of Medicine, University of Rochester , Rochester, New York
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47
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Ostrosky-Frid M, Castañeda-Bueno M, Gamba G. Regulation of the renal NaCl cotransporter by the WNK/SPAK pathway: lessons learned from genetically altered animals. Am J Physiol Renal Physiol 2018; 316:F146-F158. [PMID: 30089030 DOI: 10.1152/ajprenal.00288.2018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The renal thiazide-sensitive NaCl cotransporter (NCC) is the major salt transport pathway in the distal convoluted tubule of the mammalian nephron. NCC activity is critical for modulation of arterial blood pressure and serum potassium levels. Reduced activity of NCC in genetic diseases results in arterial hypotension and hypokalemia, while increased activity results in genetic diseases featuring hypertension and hyperkalemia. Several hormones and physiological conditions modulate NCC activity through a final intracellular complex pathway involving kinases and ubiquitin ligases. A substantial amount of work has been conducted to understand this pathway in the last 15 yr, but advances over the last 3 yr have helped to begin to understand how these regulatory proteins interact with each other and modulate the activity of this important cotransporter. In this review, we present the current model of NCC regulation by the Cullin 3 protein/Kelch-like 3 protein/with no lysine kinase/STE20-serine-proline alanine-rich kinase (CUL3/KELCH3-WNK-SPAK) pathway. We present a review of all genetically altered mice that have been used to translate most of the proposals made from in vitro experiments into in vivo observations that have helped to elucidate the model at the physiological level. Many questions have been resolved, but some others will require further models to be constructed. In addition, unexpected observations in mice have raised new questions and identified regulatory pathways that were previously unknown.
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Affiliation(s)
- Mauricio Ostrosky-Frid
- Molecular Physiology Unit, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México , Mexico City, Mexico.,PECEM, Facultad de Medicina, Universidad Nacional Autónoma de México , Mexico City, Mexico
| | - María Castañeda-Bueno
- Department of Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán , Mexico City, Mexico
| | - Gerardo Gamba
- Molecular Physiology Unit, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México , Mexico City, Mexico.,Department of Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán , Mexico City, Mexico.,Tecnológico de Monterrey, Escuela de Medicina y Ciencias de la Salud, Monterrey, Mexico
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Hashimoto H, Nomura N, Shoda W, Isobe K, Kikuchi H, Yamamoto K, Fujimaru T, Ando F, Mori T, Okado T, Rai T, Uchida S, Sohara E. Metformin increases urinary sodium excretion by reducing phosphorylation of the sodium-chloride cotransporter. Metabolism 2018; 85:23-31. [PMID: 29510178 DOI: 10.1016/j.metabol.2018.02.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 02/15/2018] [Accepted: 02/23/2018] [Indexed: 12/25/2022]
Abstract
OBJECTIVE Metformin is an antidiabetic drug that is widely used to treat patients with diabetes mellitus. Recent studies have reported that treatment with metformin not only improved blood glucose levels but also reduced blood pressure. However, it remains unclear how metformin reduces blood pressure. We hypothesized that metformin affects sodium reabsorption in the kidneys. METHODS Urinary sodium excretion and expression of renal sodium transporters were examined in 8-week-old male C57BL/6 mice with acute and chronic treatment of metformin. In addition, we examined metformin effects using ex vivo preparations of mice kidney slices. RESULTS In this study, we demonstrated that metformin increased urinary sodium excretion by reducing phosphorylation of the thiazide-sensitive Na-Cl cotransporter (NCC) in acute and chronic metformin administration. We also confirmed reduction of phosphorylated NCC in an ex vivo study. The activity of other renal sodium transporters, such as NKCC2, ENaC, and NHE3 did not show significant changes. WNK-OSR1/SPAK kinase signals were not involved in this inactivation effect of metformin on NCC. CONCLUSION Metformin increased urinary sodium excretion by reducing phosphorylation of NCC, suggesting its role in improving hypertension.
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Affiliation(s)
- Hiroko Hashimoto
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-8519, Japan
| | - Naohiro Nomura
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-8519, Japan
| | - Wakana Shoda
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-8519, Japan
| | - Kiyoshi Isobe
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-8519, Japan
| | - Hiroaki Kikuchi
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-8519, Japan
| | - Kouhei Yamamoto
- Department of Comprehensive Pathology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-8519, Japan
| | - Takuya Fujimaru
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-8519, Japan
| | - Fumiaki Ando
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-8519, Japan
| | - Takayasu Mori
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-8519, Japan
| | - Tomokazu Okado
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-8519, Japan
| | - Tatemitsu Rai
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-8519, Japan
| | - Shinichi Uchida
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-8519, Japan
| | - Eisei Sohara
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-8519, Japan.
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Barone S, Xu J, Zahedi K, Brooks M, Soleimani M. Probenecid Pre-treatment Downregulates the Kidney Cl -/HCO 3- Exchanger (Pendrin) and Potentiates Hydrochlorothiazide-Induced Diuresis. Front Physiol 2018; 9:849. [PMID: 30050451 PMCID: PMC6050369 DOI: 10.3389/fphys.2018.00849] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 06/14/2018] [Indexed: 01/14/2023] Open
Abstract
Background: Probenecid is a uricosuric agent that in addition to exerting a positive ionotropic effect in the heart, blocks the ATP transporter Pannexin 1 and inhibits the Cl-/HCO3- exchanger, pendrin. In the kidney, pendrin blunts the loss of salt wasting secondary to the inhibition of the thiazide-sensitive Na+-Cl- co-transporter (NCC/SLC12A3). Hypothesis: Pre-treatment with probenecid down-regulates pendrin; therefore, leaving NCC as the main salt absorbing transporter in the distal nephron, and hence enhances the hydrochlorothiazide (HCTZ)-induced diuresis. Methods: Daily balance studies, blood and urine chemical analysis, immunofluorescence, as well as western and northern blot analyses were utilized to examine the effects of probenecid alone (at 250 mg/kg/day) or in combination with HCTZ (at 40 mg/kg/day) on kidney function and on salt and water transporters in the collecting duct. Results: Male Sprague Dawley rats were subjected to three different protocols: (1) HCTZ for 4 days, (2) probenecid for 10 days, and (3) primed with probenecid for 6 days followed by probenecid and HCTZ for 4 additional days. Treatment protocol 1 (HCTZ for 4 days) only mildly increased the urine volume (U Vol) from a baseline of 9.8-13.4 ml/day. In response to treatment protocol 2 (probenecid for 10 days), U Vol increased to 15.9 ml/24 h. Treatment protocol 3 (probenecid for 6 days followed by probenecid and HCTZ for 4 additional days) increased the U Vol to 42.9 ml/day on day 4 of co-treatment with HCTZ and probenecid (compared to probenecid p = 0.003, n = 5 or HCTZ alone p = 0.001, n = 5). Probenecid treatment at 250 mg/kg/day downregulated the expression of pendrin and led to a decrease in AQP2 expression. Enhanced diuresis by probenecid plus HCTZ was not associated with volume depletion. Conclusion: Probenecid pre-treatment downregulates pendrin and robustly enhances diuresis by HCTZ-mediated NCC inhibition in kidney.
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Affiliation(s)
- Sharon Barone
- Department of Medicine, University of Cincinnati, Cincinnati, OH, United States
- Research Services, VA Medical Center, Cincinnati, OH, United States
| | - Jie Xu
- Department of Medicine, University of Cincinnati, Cincinnati, OH, United States
- Center on Genetics of Transport and Epithelial Biology, University of Cincinnati, Cincinnati, OH, United States
| | - Kamyar Zahedi
- Department of Medicine, University of Cincinnati, Cincinnati, OH, United States
- Research Services, VA Medical Center, Cincinnati, OH, United States
| | - Marybeth Brooks
- Department of Medicine, University of Cincinnati, Cincinnati, OH, United States
| | - Manoocher Soleimani
- Department of Medicine, University of Cincinnati, Cincinnati, OH, United States
- Research Services, VA Medical Center, Cincinnati, OH, United States
- Center on Genetics of Transport and Epithelial Biology, University of Cincinnati, Cincinnati, OH, United States
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50
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Frische S, Chambrey R, Trepiccione F, Zamani R, Marcussen N, Alexander RT, Skjødt K, Svenningsen P, Dimke H. H +-ATPase B1 subunit localizes to thick ascending limb and distal convoluted tubule of rodent and human kidney. Am J Physiol Renal Physiol 2018; 315:F429-F444. [PMID: 29993276 DOI: 10.1152/ajprenal.00539.2017] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
The vacuolar-type H+-ATPase B1 subunit is heavily expressed in the intercalated cells of the collecting system, where it contributes to H+ transport, but has also been described in other segments of the renal tubule. This study aimed to determine the localization of the B1 subunit of the vacuolar-type H+-ATPase in the early distal nephron, encompassing thick ascending limbs (TAL) and distal convoluted tubules (DCT), in human kidney and determine whether the localization differs between rodents and humans. Antibodies directed against the H+-ATPase B1 subunit were used to determine its localization in paraffin-embedded formalin-fixed mouse, rat, and human kidneys by light microscopy and in sections of Lowicryl-embedded rat kidneys by electron microscopy. Abundant H+-ATPase B1 subunit immunoreactivity was observed in the human kidney. As expected, intercalated cells showed the strongest signal, but significant signal was also observed in apical membrane domains of the distal nephron, including TAL, macula densa, and DCT. In mouse and rat, H+-ATPase B1 subunit expression could also be detected in apical membrane domains of these segments. In rat, electron microscopy revealed that the H+-ATPase B1 subunit was located in the apical membrane. Furthermore, the H+-ATPase B1 subunit colocalized with other H+-ATPase subunits in the TAL and DCT. In conclusion, the B1 subunit is expressed in the early distal nephron. The physiological importance of H+-ATPase expression in these segments remains to be delineated in detail. The phenotype of disease-causing mutations in the B1 subunit may also relate to its presence in the TAL and DCT.
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Affiliation(s)
| | - Régine Chambrey
- INSERM 1188-Université de La Réunion, Sainte Clotilde, La Réunion, France
| | - Francesco Trepiccione
- Department of Translational Medical Sciences, University of Campania "Luigi Vanvitelli," Naples, Italy
| | - Reza Zamani
- Department of Urology, Odense University Hospital , Odense , Denmark
| | - Niels Marcussen
- Department of Clinical Pathology, Odense University Hospital , Odense , Denmark
| | - R Todd Alexander
- Department of Pediatrics, University of Alberta , Edmonton, Alberta , Canada.,Membrane Protein Disease Research Group, University of Alberta , Edmonton, Alberta , Canada
| | - Karsten Skjødt
- Department of Cancer and Inflammation, Institute of Molecular Medicine, University of Southern Denmark , Odense , Denmark
| | - Per Svenningsen
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark , Odense , Denmark
| | - Henrik Dimke
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark , Odense , Denmark
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