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Morrison AR. Magnesium Homeostasis: Lessons from Human Genetics. Clin J Am Soc Nephrol 2023; 18:969-978. [PMID: 36723340 PMCID: PMC10356123 DOI: 10.2215/cjn.0000000000000103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 01/20/2023] [Indexed: 02/02/2023]
Abstract
Mg 2+ , the fourth most abundant cation in the body, serves as a cofactor for about 600 cellular enzymes. One third of ingested Mg 2+ is absorbed from the gut through a saturable transcellular process and a concentration-dependent paracellular process. Absorbed Mg 2+ is excreted by the kidney and maintains serum Mg 2+ within a narrow range of 0.7-1.25 mmol/L. The reabsorption of Mg 2+ by the nephron is characterized by paracellular transport in the proximal tubule and thick ascending limb. The nature of the transport pathways in the gut epithelia and thick ascending limb has emerged from an understanding of the molecular mechanisms responsible for rare monogenetic disorders presenting with clinical hypomagnesemia. These human disorders due to loss-of-function mutations, in concert with mouse models, have led to a deeper understanding of Mg 2+ transport in the gut and renal tubule. This review focuses on the nature of the transporters and channels revealed by human and mouse genetics and how they are integrated into an understanding of human Mg 2+ physiology.
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Affiliation(s)
- Aubrey R Morrison
- Division of Nephrology, Department of Medicine and Developmental Biology, Washington University School of Medicine, St. Louis, Missouri
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2
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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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Schlingmann KP, Jouret F, Shen K, Nigam A, Arjona FJ, Dafinger C, Houillier P, Jones DP, Kleinerüschkamp F, Oh J, Godefroid N, Eltan M, Güran T, Burtey S, Parotte MC, König J, Braun A, Bos C, Ibars Serra M, Rehmann H, Zwartkruis FJ, Renkema KY, Klingel K, Schulze-Bahr E, Schermer B, Bergmann C, Altmüller J, Thiele H, Beck BB, Dahan K, Sabatini D, Liebau MC, Vargas-Poussou R, Knoers NV, Konrad M, de Baaij JH. mTOR-Activating Mutations in RRAGD Are Causative for Kidney Tubulopathy and Cardiomyopathy. J Am Soc Nephrol 2021; 32:2885-2899. [PMID: 34607910 PMCID: PMC8806087 DOI: 10.1681/asn.2021030333] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 07/07/2021] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Over the last decade, advances in genetic techniques have resulted in the identification of rare hereditary disorders of renal magnesium and salt handling. Nevertheless, approximately 20% of all patients with tubulopathy lack a genetic diagnosis. METHODS We performed whole-exome and -genome sequencing of a patient cohort with a novel, inherited, salt-losing tubulopathy; hypomagnesemia; and dilated cardiomyopathy. We also conducted subsequent in vitro functional analyses of identified variants of RRAGD, a gene that encodes a small Rag guanosine triphosphatase (GTPase). RESULTS In eight children from unrelated families with a tubulopathy characterized by hypomagnesemia, hypokalemia, salt wasting, and nephrocalcinosis, we identified heterozygous missense variants in RRAGD that mostly occurred de novo. Six of these patients also had dilated cardiomyopathy and three underwent heart transplantation. We identified a heterozygous variant in RRAGD that segregated with the phenotype in eight members of a large family with similar kidney manifestations. The GTPase RagD, encoded by RRAGD, plays a role in mediating amino acid signaling to the mechanistic target of rapamycin complex 1 (mTORC1). RagD expression along the mammalian nephron included the thick ascending limb and the distal convoluted tubule. The identified RRAGD variants were shown to induce a constitutive activation of mTOR signaling in vitro. CONCLUSIONS Our findings establish a novel disease, which we call autosomal dominant kidney hypomagnesemia (ADKH-RRAGD), that combines an electrolyte-losing tubulopathy and dilated cardiomyopathy. The condition is caused by variants in the RRAGD gene, which encodes Rag GTPase D; these variants lead to an activation of mTOR signaling, suggesting a critical role of Rag GTPase D for renal electrolyte handling and cardiac function.
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Affiliation(s)
- Karl P. Schlingmann
- Department of General Pediatrics, University Children’s Hospital, Münster, Germany
| | - François Jouret
- Division of Nephrology, Department of Internal Medicine, University of Liège Hospital, Liège, Belgium,Interdisciplinary Group of Applied Genoproteomics, Cardiovascular Sciences, University of Liège, Liège, Belgium
| | - Kuang Shen
- Whitehead Institute for Biomedical Research, Cambridge, Massachusetts,Department of Biology, Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, Massachusetts,Koch Institute for Integrative Cancer Research, Cambridge, Massachusetts,Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, Massachusetts,Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Anukrati Nigam
- Department of Genetics, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Francisco J. Arjona
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Claudia Dafinger
- Department of Pediatrics and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne and University Hospital Cologne, Cologne, Germany,Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne and University Hospital Cologne, Cologne, Germany
| | - Pascal Houillier
- Cordeliers Research Center, Centre National de la Recherche Scientifique (CNRS), ERL8228, Institut National de la Santé et de la Recherche Médicale (INSERM), Sorbonne University, University of Paris, Paris, France,Department of Physiology, Assistance Publique-Hôpitaux de Paris (AP-HP), European Hospital Georges Pompidou, Paris, France,Reference Center for Hereditary Renal Diseases in Children and Adults (MARHEA), Paris, France
| | - Deborah P. Jones
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Felix Kleinerüschkamp
- Department of Pediatric Cardiology, University Children’s Hospital, Münster, Germany
| | - Jun Oh
- Department of Pediatrics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Nathalie Godefroid
- Division of Pediatric Nephrology, Saint-Luc University Clinics, Catholic University of Louvain, Brussels, Belgium
| | - Mehmet Eltan
- Department of Pediatric Endocrinology and Diabetes, School of Medicine, Marmara University, Istanbul, Turkey
| | - Tülay Güran
- Department of Pediatric Endocrinology and Diabetes, School of Medicine, Marmara University, Istanbul, Turkey
| | - Stéphane Burtey
- Center for Nephrology and Renal Transplantation, Assistance Publique-Hôpitaux de Marseille, Aix-Marseille University, Marseille, France
| | - Marie-Christine Parotte
- Division of Nephrology-Dialysis, Department of Internal Medicine, CHR Verviers East Belgium, Verviers, Belgium
| | - Jens König
- Department of General Pediatrics, University Children’s Hospital, Münster, Germany
| | - Alina Braun
- Department of Pediatrics and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne and University Hospital Cologne, Cologne, Germany,Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne and University Hospital Cologne, Cologne, Germany
| | - Caro Bos
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Maria Ibars Serra
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Holger Rehmann
- Department of Molecular Cancer Research, Center for Molecular Medicine, Oncode Institute, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Fried J.T. Zwartkruis
- Department of Molecular Cancer Research, Center for Molecular Medicine, Oncode Institute, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Kirsten Y. Renkema
- Department of Genetics, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Karin Klingel
- Cardiopathology, Institute for Pathology and Neuropathology, University Hospital Tübingen, Tübingen, Germany
| | - Eric Schulze-Bahr
- Institute for Genetics of Heart Diseases (IfGH), Department of Cardiovascular Medicine, University Hospital Münster, Münster, Germany
| | - Bernhard Schermer
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne and University Hospital Cologne, Cologne, Germany,CECAD, Faculty of Medicine, University of Cologne and University Hospital Cologne, Cologne, Germany
| | - Carsten Bergmann
- Limbach Genetics, Medizinische Genetik Mainz, Mainz, Germany,Division of Nephrology, Department of Medicine, University Hospital Freiburg, Breisgau, Germany
| | - Janine Altmüller
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Holger Thiele
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Bodo B. Beck
- Institute of Human Genetics, University Hospital Cologne and University of Cologne, Faculty of Medicine, Cologne, Germany,Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine, University Hospital Cologne, Cologne, Germany,Center for Rare Diseases, Medical Faculty, University of Cologne and University Hospital Cologne, Cologne, Germany
| | - Karin Dahan
- Center of Human Genetics, Gosselies, Belgium,Division of Nephrology, Saint-Luc University Clinics, Catholic University of Louvain, Brussels, Belgium
| | - David Sabatini
- Whitehead Institute for Biomedical Research, Cambridge, Massachusetts,Department of Biology, Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, Massachusetts,Koch Institute for Integrative Cancer Research, Cambridge, Massachusetts,Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Max C. Liebau
- Department of Pediatrics and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne and University Hospital Cologne, Cologne, Germany,Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne and University Hospital Cologne, Cologne, Germany,Center for Rare Diseases, Medical Faculty, University of Cologne and University Hospital Cologne, Cologne, Germany
| | - Rosa Vargas-Poussou
- Department of Genetics, AP-HP, European Hospital Georges Pompidou, Paris, France
| | - Nine V.A.M. Knoers
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Martin Konrad
- Department of General Pediatrics, University Children’s Hospital, Münster, Germany
| | - Jeroen H.F. de Baaij
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
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Liamis G, Hoorn EJ, Florentin M, Milionis H. An overview of diagnosis and management of drug-induced hypomagnesemia. Pharmacol Res Perspect 2021; 9:e00829. [PMID: 34278747 PMCID: PMC8287009 DOI: 10.1002/prp2.829] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 03/18/2021] [Accepted: 06/01/2021] [Indexed: 12/29/2022] Open
Abstract
Magnesium (Mg) is commonly addressed as the "forgotten ion" in medicine. Nonetheless, hypomagnesemia should be suspected in clinical practice in patients with relevant symptomatology and also be considered a predisposing factor for the development of other electrolyte disturbances. Furthermore, chronic hypomagnesemia has been associated with diabetes mellitus and cardiovascular disease. Hypomagnesemia as a consequence of drug therapy is relatively common, with the list of drugs inducing low serum Mg levels expanding. Culprit medications linked to hypomagnesemia include antibiotics (e.g. aminoglycosides, amphotericin B), diuretics, antineoplastic drugs (cisplatin and cetuximab), calcineurin inhibitors, and proton pump inhibitors. In recent years, the mechanisms of drug-induced hypomagnesemia have been unraveled through the discovery of key Mg transporters in the gut and kidney. This narrative review of available literature focuses on the pathogenetic mechanisms underlying drug-induced hypomagnesemia in order to increase the insight of clinicians toward early diagnosis and effective management.
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Affiliation(s)
- George Liamis
- Department of Internal Medicine, School of Medicine, University of Ioannina, Ioannina, Greece
| | - Ewout J Hoorn
- Division of Nephrology and Transplantation, Department of Internal Medicine, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Matilda Florentin
- Department of Internal Medicine, School of Medicine, University of Ioannina, Ioannina, Greece
| | - Haralampos Milionis
- Department of Internal Medicine, School of Medicine, University of Ioannina, Ioannina, Greece
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Wu J, Lai G, Chen F, Zhang B, Zhao Y. Renal NKCC2 Is Dual Regulated by the Synergy of 20-HETE and High-Fat Diet in CYP4F2 Transgenic Mice. Kidney Blood Press Res 2021; 46:601-612. [PMID: 34320496 DOI: 10.1159/000517382] [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: 01/28/2021] [Accepted: 04/22/2021] [Indexed: 11/19/2022] Open
Abstract
INTRODUCTION 20-Hydroxyeicosatetraenoic acid (20-HETE) is the metabolite of cytochrome P450, which modulates blood pressure by inhibiting renal sodium transport. However, the molecular mechanisms underlying the role of 20-HETE in the development of obesity-related hypertension remain unclear, necessitating this study. METHODS Cytochrome P450 4F2 (CYP4F2) transgenic mice fed high-fat diet (HFD) were used as research animal models. The expression of renal ion transport molecules targeted by 20-HETE was evaluated by real-time PCR and Western blot (WB). The regulatory effect of 20-HETE and HFD on renal Na+-K+-2Cl- cotransporter, isoform 2 (NKCC2) was explored by immunoprecipitation, WB, and luciferase assay. RESULTS A 2-week HFD feeding dramatically decreased protein abundance but increased renal NKCC2 mRNA expression in CYP4F2 transgenic mice. The decrease in NKCC2 protein was demonstrated to be due to ubiquitination induced by the synergy between 20-HETE and HFD. The increased PPAR-γ protein in CYP4F2 transgenic mice fed HFD and the activation of rosiglitazone on the luciferase reporter construct of the NKCC2 promoter demonstrated that the increase in NKCC2 mRNA in CYP4F2 transgenic mice fed HFD was a consequence of elevated PPAR-γ protein induced by the synergy between 20-HETE and HFD. CONCLUSIONS Our data demonstrated that the synergy between 20-HETE and HFD could decrease NKCC2 protein via posttranslational ubiquitination, which was thought to be the main mechanism underlying the short-term effect in response to HFD and might be responsible for the adaptive modulation of renal NKCC2 to resist sodium retention. Moreover, the increased NKCC2 mRNA expression via PPAR-γ-induced transcriptional regulation was thought to be the main mechanism underlying the long-term effect in response to HFD and plays a pivotal role in the development of obesity-related hypertension.
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Affiliation(s)
- Jingjing Wu
- Department of Medical Genetics, School of Life Sciences, China Medical University, Shenyang, China,
| | - Guangrui Lai
- Department of Clinical Genetics, Shengjing Hospital of China Medical University, Shenyang, China
| | - Fangjie Chen
- Department of Medical Genetics, School of Life Sciences, China Medical University, Shenyang, China
| | - Bijun Zhang
- Department of Clinical Genetics, Shengjing Hospital of China Medical University, Shenyang, China
| | - Yanyan Zhao
- Department of Medical Genetics, School of Life Sciences, China Medical University, Shenyang, China
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6
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Abstract
Magnesium (Mg2+) plays an essential role in many biological processes. Mg2+ deficiency is therefore associated with a wide range of clinical effects including muscle cramps, fatigue, seizures and arrhythmias. To maintain sufficient Mg2+ levels, (re)absorption of Mg2+ in the intestine and kidney is tightly regulated. Genetic defects that disturb Mg2+ uptake pathways, as well as drugs interfering with Mg2+ (re)absorption cause hypomagnesemia. The aim of this review is to provide an overview of the molecular mechanisms underlying genetic and drug-induced Mg2+ deficiencies. This leads to the identification of four main mechanisms that are affected by hypomagnesemia-causing mutations or drugs: luminal transient receptor potential melastatin type 6/7-mediated Mg2+ uptake, paracellular Mg2+ reabsorption in the thick ascending limb of Henle's loop, structural integrity of the distal convoluted tubule and Na+-dependent Mg2+ extrusion driven by the Na+/K+-ATPase. Our analysis demonstrates that genetic and drug-induced causes of hypomagnesemia share common molecular mechanisms. Targeting these shared pathways can lead to novel treatment options for patients with hypomagnesemia.
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7
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Grabowska M, Michałek K, Kędzierska-Kapuza K, Kram A, Gill K, Piasecka M. The long-term effects of rapamycin-based immunosuppressive protocols on the expression of renal aquaporins 1, 2, 3 and 4 water channels in rats. Histol Histopathol 2021; 36:459-474. [PMID: 33634832 DOI: 10.14670/hh-18-321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND To this day, the effect of multi-drug immunosuppressive protocols on renal expression of AQPs is unknown. This study aimed to determine the influence of rapamycin-based multi-drug immunosuppressive regimens on the expression of aquaporins (AQPs) 1, 2, 3, and 4 in the rat kidney. METHODS For 6 months, 24 male Wistar rats were administered immunosuppressants, according to the three-drug protocols used in patients after organ transplantation. The rats were divided into four groups: the control group, the TRP group (tacrolimus, rapamycin, prednisone), the CRP group (cyclosporine A, rapamycin, prednisone), and the MRP group (mycophenolate mofetil, rapamycin, prednisone). Selected red cell indices and total calcium were measured in the blood of rats and quantitative analysis of AQP1, AQP2, AQP3 and AQP4 immunoexpression in the kidneys were performed. RESULTS In the TRP and CRP groups, a mild increase of mean corpuscular hemoglobin concentration, hematocrit and total calcium were observed. Moreover, decreased expression of AQP1-4 was found in all experimental groups, with the highest decrease in the CRP group. CONCLUSIONS The long-term immunosuppressive treatment using multi-drug protocols decreased AQP1-4 expressions in renal tubules, possibly leading to impaired urine-concentrating ability in rat.
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Affiliation(s)
- Marta Grabowska
- Department of Histology and Developmental Biology, Pomeranian Medical University, Szczecin, Poland
| | - Katarzyna Michałek
- Department of Physiology, Cytobiology and Proteomics, West Pomeranian University of Technology, Szczecin, Poland
| | - Karolina Kędzierska-Kapuza
- Department of Gastroenterological Surgery and Transplantation, Central Hospital of Ministry of Internal Affairs and Administration in Warsaw, Medical Center for Postgraduate Education, Warsaw, Poland
| | - Andrzej Kram
- Department of Pathology, West Pomeranian Oncology Center, Szczecin, Poland
| | - Kamil Gill
- Department of Histology and Developmental Biology, Pomeranian Medical University, Szczecin, Poland
| | - Małgorzata Piasecka
- Department of Histology and Developmental Biology, Pomeranian Medical University, Szczecin, Poland.
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8
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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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Ram E, Lavee J, Shechter M, Kogan A, Maor E, Asher E, Freimark D, Klempfner R, Peled Y. Relation of Low Serum Magnesium to Mortality and Cardiac Allograft Vasculopathy Following Heart Transplantation. Am J Cardiol 2020; 125:1517-1523. [PMID: 32238278 DOI: 10.1016/j.amjcard.2020.02.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 02/08/2020] [Accepted: 02/12/2020] [Indexed: 11/25/2022]
Abstract
Hypomagnesemia is commonly observed in heart transplant (HT) recipients receiving calcineurin inhibitors. Since low serum magnesium (s-Mg) has been implicated in the progression of atherosclerosis, potentially leading to worsening coronary heart disease, arrhythmias and sudden death, we investigated the association between s-Mg and HT outcomes. Between 2002 and 2017, 150 HT patients assessed for s-Mg were divided into high (≥1.7 mg/dL) and low s-Mg groups according to the median value of all s-Mg levels recorded during the first 3 months post-HT. Endpoints included survival, cardiac allograft vasculopathy (CAV), any-treated rejection (ATR) and NF-MACE. Kaplan-Meier analysis showed that at 15 years after HT, both survival (76 vs 33%, log-rank p = 0.007) and freedom from CAV (75 vs 48%, log-rank p = 0.01) were higher in the high versus low s-Mg group. There were no significant differences in freedom from NF-MACE or ATR. Multivariate analyses consistently demonstrated that low s-Mg was independently associated with a significant 2.6-fold increased risk of mortality and 4-fold increased risk of CAV (95%CI 1.06 to 6.4, p = 0.04; 95%CI 1.12 to 14.42, p = 0.01, respectively). In conclusion, low s-Mg is independently associated with increased mortality and CAV in HT patients. Larger multi-center prospective studies are needed to confirm these findings and to examine the effect of Mg supplementation.
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Cao H, Luo J, Zhang Y, Mao X, Wen P, Ding H, Xu J, Sun Q, He W, Dai C, Zen K, Zhou Y, Yang J, Jiang L. Tuberous sclerosis 1 (Tsc1) mediated mTORC1 activation promotes glycolysis in tubular epithelial cells in kidney fibrosis. Kidney Int 2020; 98:686-698. [PMID: 32739207 DOI: 10.1016/j.kint.2020.03.035] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 03/12/2020] [Accepted: 03/19/2020] [Indexed: 10/24/2022]
Abstract
Energy reprogramming to glycolysis is closely associated with the development of chronic kidney disease. As an important negative regulatory factor of the mammalian target of rapamycin complex 1 (mTORC1) signal, tuberous sclerosis complex 1 (Tsc1) is also a key regulatory point of glycolysis. Here, we investigated whether Tsc1 could mediate the progression of kidney interstitial fibrosis by regulating glycolysis in proximal tubular epithelial cells. We induced mTORC1 signal activation in tubular epithelial cells in kidneys with fibrosis via unilateral ureteral occlusion. This resulted in increased tubular epithelial cell proliferation and glycolytic enzyme upregulation. Prior incubation with rapamycin inhibited mTORC1 activation and abolished the enhanced glycolysis and tubular epithelial cell proliferation. Furthermore, knockdown of Tsc1 expression promoted glycolysis in the rat kidney epithelial cell line NRK-52E. Specific deletion of Tsc1 in the proximal tubules of mice resulted in enlarged kidneys characterized by a high proportion of proliferative tubular epithelial cells, dilated tubules with cyst formation, and a large area of interstitial fibrosis in conjunction with elevated glycolysis. Treatment of the mice with the glycolysis inhibitor 2-deoxyglucose notably ameliorated tubular epithelial cell proliferation, cystogenesis, and kidney fibrosis. Thus, our findings suggest that Tsc1-associated mTORC1 signaling mediates the progression of kidney interstitial fibrosis by regulating glycolysis in proximal tubular epithelial cells.
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Affiliation(s)
- Hongdi Cao
- Center for Kidney Disease, 2nd Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Jing Luo
- Center for Kidney Disease, 2nd Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Yu Zhang
- Center for Kidney Disease, 2nd Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Xiaoming Mao
- Center for Kidney Disease, 2nd Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Ping Wen
- Center for Kidney Disease, 2nd Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Hao Ding
- Center for Kidney Disease, 2nd Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Jing Xu
- Center for Kidney Disease, 2nd Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Qi Sun
- Center for Kidney Disease, 2nd Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Weichun He
- Center for Kidney Disease, 2nd Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Chunsun Dai
- Center for Kidney Disease, 2nd Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Ke Zen
- State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University Advanced Institute of Life Sciences, Nanjing, Jiangsu, China
| | - Yang Zhou
- Center for Kidney Disease, 2nd Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, China.
| | - Junwei Yang
- Center for Kidney Disease, 2nd Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, China.
| | - Lei Jiang
- Center for Kidney Disease, 2nd Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, China.
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Serum Magnesium after Kidney Transplantation: A Systematic Review. Nutrients 2018; 10:nu10060729. [PMID: 29882768 PMCID: PMC6024843 DOI: 10.3390/nu10060729] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 05/28/2018] [Accepted: 05/31/2018] [Indexed: 12/15/2022] Open
Abstract
Magnesium (Mg) status has recently drawn close attention in chronic kidney disease and in kidney transplant recipients. This review aims to evaluate the body of evidence linking hypomagnesemia to clinical consequences in these specific populations. After a brief summary of the main mechanisms involved in Mg regulation and of Mg status in end-stage renal disease, the review focuses on the relationship between hypomagnesemia and cardiovascular risk in kidney transplant recipients. A body of evidence in recent studies points to a negative impact of hypomagnesemia on post-transplant diabetes mellitus (PTDM) and cardiovascular risk, which currently represent the main threat for morbidity and mortality in kidney transplantation. Deleterious biological mechanisms induced by hypomagnesemia are also discussed. While data analysis enables us to conclude that hypomagnesemia is linked to the development of PTDM, studies prospectively evaluating the impact of hypomagnesemia correction after kidney transplantation are still lacking and needed.
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12
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William JH, Richards K, Danziger J. Magnesium and Drugs Commonly Used in Chronic Kidney Disease. Adv Chronic Kidney Dis 2018; 25:267-273. [PMID: 29793666 DOI: 10.1053/j.ackd.2018.01.005] [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] [Received: 07/19/2017] [Revised: 01/20/2018] [Accepted: 01/22/2018] [Indexed: 12/20/2022]
Abstract
As with other electrolytes, magnesium homeostasis depends on the balance between gastrointestinal absorption and kidney excretion. Certain drugs used commonly in patients with CKD can decrease gastrointestinal ingestion and kidney reclamation, and potentially cause hypomagnesemia. Other magnesium-containing drugs such as laxatives and cathartics can induce hypermagnesemia, particularly in those with impaired glomerular filtration and magnesium excretion. In this review, we will discuss the potential magnesium complications associated with a range of commonly encountered drugs in the care of CKD patients, discuss the potential mechanisms, and provide basic clinical recommendations.
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13
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Filippatos T, Tzavella E, Rizos C, Elisaf M, Liamis G. Acid-base and electrolyte disorders associated with the use of antidiabetic drugs. Expert Opin Drug Saf 2017; 16:1121-1132. [DOI: 10.1080/14740338.2017.1361400] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Theodosios Filippatos
- Department of Internal Medicine, School of Medicine, University of Ioannina, Ioannina, Greece
| | - Eleftheria Tzavella
- Department of Internal Medicine, School of Medicine, University of Ioannina, Ioannina, Greece
| | - Christos Rizos
- Department of Internal Medicine, School of Medicine, University of Ioannina, Ioannina, Greece
| | - Moses Elisaf
- Department of Internal Medicine, School of Medicine, University of Ioannina, Ioannina, Greece
| | - George Liamis
- Department of Internal Medicine, School of Medicine, University of Ioannina, Ioannina, Greece
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14
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Roles of mTOR complexes in the kidney: implications for renal disease and transplantation. Nat Rev Nephrol 2016; 12:587-609. [PMID: 27477490 DOI: 10.1038/nrneph.2016.108] [Citation(s) in RCA: 143] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The mTOR pathway has a central role in the regulation of cell metabolism, growth and proliferation. Studies involving selective gene targeting of mTOR complexes (mTORC1 and mTORC2) in renal cell populations and/or pharmacologic mTOR inhibition have revealed important roles of mTOR in podocyte homeostasis and tubular transport. Important advances have also been made in understanding the role of mTOR in renal injury, polycystic kidney disease and glomerular diseases, including diabetic nephropathy. Novel insights into the roles of mTORC1 and mTORC2 in the regulation of immune cell homeostasis and function are helping to improve understanding of the complex effects of mTOR targeting on immune responses, including those that impact both de novo renal disease and renal allograft outcomes. Extensive experience in clinical renal transplantation has resulted in successful conversion of patients from calcineurin inhibitors to mTOR inhibitors at various times post-transplantation, with excellent long-term graft function. Widespread use of this practice has, however, been limited owing to mTOR-inhibitor- related toxicities. Unique attributes of mTOR inhibitors include reduced rates of squamous cell carcinoma and cytomegalovirus infection compared to other regimens. As understanding of the mechanisms by which mTORC1 and mTORC2 drive the pathogenesis of renal disease progresses, clinical studies of mTOR pathway targeting will enable testing of evolving hypotheses.
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15
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Van Laecke S, Van Biesen W. Hypomagnesaemia in kidney transplantation. Transplant Rev (Orlando) 2015; 29:154-60. [PMID: 26001746 DOI: 10.1016/j.trre.2015.05.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2015] [Accepted: 05/03/2015] [Indexed: 01/14/2023]
Abstract
In the era of calcineurin inhibitors, hypomagnesaemia is a very common finding in kidney transplant recipients. Especially the first weeks after transplantation it is the rule rather than the exception. Hypomagnesaemia or low magnesium intake have been associated with a higher mortality or more cardiovascular events in the general population, but this association has never been explored in kidney transplant recipients, despite their increased cardiovascular risk. Kidney transplant recipients with pre- or post-transplant hypomagnesaemia seem to have an aberrant glucose metabolism and develop diabetes mellitus more frequently. Moreover, observations from alternate study populations, animal experiments or in vitro studies suggest a possible role of magnesium deficiency in graft dysfunction, bone metabolism and transplant immunology. Future observational and especially interventional studies should further define whether and to what extent we should make effort to correct this electrolyte disturbance in transplant recipients. Considering the mechanism of renal magnesium wasting, normalizing the serum magnesium concentration by oral supplementation alone might turn out to be cumbersome in kidney transplant recipients.
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Affiliation(s)
| | - Wim Van Biesen
- Renal Division, Ghent University Hospital, Ghent, Belgium.
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16
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de Baaij JHF, Hoenderop JGJ, Bindels RJM. Magnesium in man: implications for health and disease. Physiol Rev 2015; 95:1-46. [PMID: 25540137 DOI: 10.1152/physrev.00012.2014] [Citation(s) in RCA: 880] [Impact Index Per Article: 97.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Magnesium (Mg(2+)) is an essential ion to the human body, playing an instrumental role in supporting and sustaining health and life. As the second most abundant intracellular cation after potassium, it is involved in over 600 enzymatic reactions including energy metabolism and protein synthesis. Although Mg(2+) availability has been proven to be disturbed during several clinical situations, serum Mg(2+) values are not generally determined in patients. This review aims to provide an overview of the function of Mg(2+) in human health and disease. In short, Mg(2+) plays an important physiological role particularly in the brain, heart, and skeletal muscles. Moreover, Mg(2+) supplementation has been shown to be beneficial in treatment of, among others, preeclampsia, migraine, depression, coronary artery disease, and asthma. Over the last decade, several hereditary forms of hypomagnesemia have been deciphered, including mutations in transient receptor potential melastatin type 6 (TRPM6), claudin 16, and cyclin M2 (CNNM2). Recently, mutations in Mg(2+) transporter 1 (MagT1) were linked to T-cell deficiency underlining the important role of Mg(2+) in cell viability. Moreover, hypomagnesemia can be the consequence of the use of certain types of drugs, such as diuretics, epidermal growth factor receptor inhibitors, calcineurin inhibitors, and proton pump inhibitors. This review provides an extensive and comprehensive overview of Mg(2+) research over the last few decades, focusing on the regulation of Mg(2+) homeostasis in the intestine, kidney, and bone and disturbances which may result in hypomagnesemia.
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Affiliation(s)
- Jeroen H F de Baaij
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Joost G J Hoenderop
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - René J M Bindels
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
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17
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Pham PCT, Pham PAT, Pham SV, Pham PTT, Pham PMT, Pham PTT. Hypomagnesemia: a clinical perspective. Int J Nephrol Renovasc Dis 2014; 7:219-30. [PMID: 24966690 PMCID: PMC4062555 DOI: 10.2147/ijnrd.s42054] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Although magnesium is involved in a wide spectrum of vital functions in normal human physiology, the significance of hypomagnesemia and necessity for its treatment are under-recognized and underappreciated in clinical practice. In the current review, we first present an overview of the clinical significance of hypomagnesemia and normal magnesium metabolism, with a focus on renal magnesium handling. Subsequently, we review the literature for both congenital and acquired hypomagnesemic conditions that affect the various steps in normal magnesium metabolism. Finally, we present an approach to the routine evaluation and suggested management of hypomagnesemia.
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Affiliation(s)
| | - Phuong-Anh T Pham
- Veterans Administration Central California Health Care System, Fresno, CA, USA
| | - Son V Pham
- South Texas Veterans Health Care System and University of Texas Health Science Center, San Antonio, TX, USA
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18
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Van Ende C, Van Laecke S, Marechal C, Verbeke F, Kanaan N, Goffin E, Vanholder R, Jadoul M. Proton-pump inhibitors do not influence serum magnesium levels in renal transplant recipients. J Nephrol 2014; 27:707-11. [PMID: 24816563 DOI: 10.1007/s40620-014-0105-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Accepted: 04/23/2014] [Indexed: 12/19/2022]
Abstract
Severe hypomagnesemia has been reported with use of proton-pump inhibitors (PPIs). We assessed the effect, if any, of PPI use on serum magnesium level in a cross-sectional analysis of a large published cohort of renal transplant recipients (RTRs). Between February 2004 and February 2006, 512 consecutive prevalent RTRs were enrolled at two university hospitals in Belgium (Brussels and Ghent). Serum creatinine was 1.5 ± 0.7 mg/dl, and estimated glomerular filtration rate (eGFR) 53 ± 19 ml/min/1.73 m(2). Mean (and median) magnesium level was 1.91 ± 0.23 mg/dl. PPIs were prescribed in 20 % (n = 101) of cases. At multivariable analysis, PPI use was not an independent predictor of serum magnesium level or hypomagnesemia. The independent predictors of a lower serum magnesium level were the use of tacrolimus, cyclosporin and sirolimus, the absence of use of mycophenolate mofetil, lower levels of parathyroid hormone and higher eGFR. This study is the first to analyze the potential impact of PPIs on magnesium level in a large, representative cohort of RTR patients. Our results suggest that PPIs may be used without particular fear of favoring hypomagnesemia-related side effects in RTRs, an important finding in a population at high risk of hypomagnesemia.
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Affiliation(s)
- Charlotte Van Ende
- Department of Nephrology, Cliniques Universitaires Saint-Luc, Université Catholique de Louvain Medical School, Avenue Hippocrate 10, 1200, Brussels, Belgium
| | | | - Celine Marechal
- Department of Nephrology, Cliniques Universitaires Saint-Luc, Université Catholique de Louvain Medical School, Avenue Hippocrate 10, 1200, Brussels, Belgium
| | | | - Nada Kanaan
- Department of Nephrology, Cliniques Universitaires Saint-Luc, Université Catholique de Louvain Medical School, Avenue Hippocrate 10, 1200, Brussels, Belgium
| | - Eric Goffin
- Department of Nephrology, Cliniques Universitaires Saint-Luc, Université Catholique de Louvain Medical School, Avenue Hippocrate 10, 1200, Brussels, Belgium
| | | | - Michel Jadoul
- Department of Nephrology, Cliniques Universitaires Saint-Luc, Université Catholique de Louvain Medical School, Avenue Hippocrate 10, 1200, Brussels, Belgium.
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Abstract
TRPM6 is a bifunctional protein comprising a TRP cation channel segment covalently linked to an α-type serine/threonine protein kinase. TRPM6 is expressed in the intestinal and renal epithelial cells. Loss-of-function mutations in the human TRPM6 gene give rise to hypomagnesemia with secondary hypocalcemia (HSH), suggesting that the TRPM6 channel kinase plays a central role in systemic Mg(2+) homeostasis. In contrast, Trpm6 null mice show a delay in prenatal development, neural tube defects, and prenatal death. Possible functions of TRPM6 in prenatal and adult organisms will be discussed in this chapter.
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Affiliation(s)
- Vladimir Chubanov
- Walther-Straub-Institute for Pharmacology and Toxicology, Ludwig-Maximilians University Munich, Goethestrasse 33, Munich, 80336, Germany,
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20
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Abstract
Magnesium (Mg2+) balance is tightly regulated by the concerted actions of the intestine, bone and kidneys. This balance can be disturbed by a broad variety of drugs. Diuretics, modulators of the EGFR (epidermal growth factor receptor), proton pump inhibitors, antimicrobials, calcineurin inhibitors and cytostatics may all cause hypomagnesaemia, potentially leading to tetany, seizures and cardiac arrhythmias. Conversely, high doses of Mg2+ salts, frequently administered as an antacid or a laxative, may lead to hypermagnesaemia causing various cardiovascular and neuromuscular abnormalities. A better understanding of the molecular mechanisms underlying the adverse effects of these medications on Mg2+ balance will indicate ways of prevention and treatment of these adverse effects and could potentially provide more insight into Mg2+ homoeostasis.
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Säemann MD, Krebs M. Thiazolidinediones in the treatment of patients with Post-Transplant-Hyperglycemia or new-onset diabetes mellitus after renal transplantation (NODAT) – A new therapeutic option? Wien Klin Wochenschr 2010; 122:198-202. [DOI: 10.1007/s00508-010-1369-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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