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Banki E, Fisi V, Moser S, Wengi A, Carrel M, Loffing-Cueni D, Penton D, Kratschmar DV, Rizzo L, Lienkamp S, Odermatt A, Rinschen MM, Loffing J. Specific disruption of calcineurin-signaling in the distal convoluted tubule impacts the transcriptome and proteome, and causes hypomagnesemia and metabolic acidosis. Kidney Int 2021; 100:850-869. [PMID: 34252449 DOI: 10.1016/j.kint.2021.06.030] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 06/11/2021] [Accepted: 06/18/2021] [Indexed: 12/27/2022]
Abstract
Adverse effects of calcineurin inhibitors (CNI), such as hypertension, hyperkalemia, acidosis, hypomagnesemia and hypercalciuria, have been linked to dysfunction of the distal convoluted tubule (DCT). To test this, we generated a mouse model with an inducible DCT-specific deletion of the calcineurin regulatory subunit B alpha (CnB1-KO). Three weeks after CnB1 deletion, these mice exhibited hypomagnesemia and acidosis, but no hypertension, hyperkalemia or hypercalciuria. Consistent with the hypomagnesemia, CnB1-KO mice showed a downregulation of proteins implicated in DCT magnesium transport, including TRPM6, CNNM2, SLC41A3 and parvalbumin but expression of calcium channel TRPV5 in the kidney was unchanged. The abundance of the chloride/bicarbonate exchanger pendrin was increased, likely explaining the acidosis. Plasma aldosterone levels, kidney renin expression, abundance of phosphorylated sodium chloride-cotransporter and abundance of the epithelial sodium channel were similar in control and CnB1-KO mice, consistent with a normal sodium balance. Long-term potassium homeostasis was maintained in CnB1-KO mice, but in-vivo and ex-vivo experiments indicated that CnB1 contributes to acute regulation of potassium balance and sodium chloride-cotransporter. Tacrolimus treatment of control and CnB1-KO mice demonstrated that CNI-related hypomagnesemia is linked to impaired calcineurin-signaling in DCT, while hypocalciuria and hyponatremia occur independently of CnB1 in DCT. Transcriptome and proteome analyses of isolated DCTs demonstrated that CnB1 deletion impacts the expression of several DCT-specific proteins and signaling pathways. Thus, our data support a critical role of calcineurin for DCT function and provide novel insights into the pathophysiology of CNI side-effects and involved molecular players in the DCT.
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Affiliation(s)
- Eszter Banki
- Institute of Anatomy, University of Zurich, Zurich, Switzerland; Swiss National Centre for Competence in Research "Kidney Control of Homeostasis," Zurich, Switzerland
| | - Viktoria Fisi
- Institute of Anatomy, University of Zurich, Zurich, Switzerland
| | - Sandra Moser
- Institute of Anatomy, University of Zurich, Zurich, Switzerland
| | - Agnieszka Wengi
- Institute of Anatomy, University of Zurich, Zurich, Switzerland
| | - Monique Carrel
- Institute of Anatomy, University of Zurich, Zurich, Switzerland
| | | | - David Penton
- Institute of Anatomy, University of Zurich, Zurich, Switzerland; Swiss National Centre for Competence in Research "Kidney Control of Homeostasis," Zurich, Switzerland
| | - Denise V Kratschmar
- Department of Pharmaceutical Sciences, Division of Molecular and Systems Toxicology, University of Basel, Basel, Switzerland
| | - Ludovica Rizzo
- Institute of Anatomy, University of Zurich, Zurich, Switzerland
| | - Soeren Lienkamp
- Institute of Anatomy, University of Zurich, Zurich, Switzerland; Swiss National Centre for Competence in Research "Kidney Control of Homeostasis," Zurich, Switzerland
| | - Alex Odermatt
- Department of Pharmaceutical Sciences, Division of Molecular and Systems Toxicology, University of Basel, Basel, Switzerland
| | - Markus M Rinschen
- Kidney Research Center, University of Cologne, Köln, Germany; Department of Biomedicine, Aarhus University, Aarhus, Denmark; III Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Johannes Loffing
- Institute of Anatomy, University of Zurich, Zurich, Switzerland; Swiss National Centre for Competence in Research "Kidney Control of Homeostasis," Zurich, Switzerland.
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Ayuk J, Gittoes NJL. Contemporary view of the clinical relevance of magnesium homeostasis. Ann Clin Biochem 2014; 51:179-88. [PMID: 24402002 DOI: 10.1177/0004563213517628] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Magnesium is one of the most abundant cations in the body and is essential for a wide variety of metabolically important reactions. Serum magnesium concentration is regulated by the balance between intestinal absorption and renal excretion. Hypomagnesaemia is relatively common, with an estimated prevalence in the general population ranging from 2.5 to 15%. It may result from inadequate magnesium intake, increased gastrointestinal or renal loss or redistribution from extracellular to intracellular space. Drug-induced hypomagnesaemia, particularly related to proton-pump inhibitor (PPI) therapy, is being increasingly recognized. Although most patients with hypomagnesaemia are asymptomatic, manifestations may include neuromuscular, cardiovascular and metabolic features. Due to the kidney's ability to increase fractional excretion to nearly 100% when the renal magnesium threshold is exceeded, clinically significant hypermagnesaemia is uncommon, generally occurring only in the setting of renal insufficiency and excessive magnesium intake. Symptoms include hypotension, nausea, facial flushing, ileus and flaccid muscle paralysis. In most cases, simply withdrawing exogenous magnesium is sufficient to restore normal magnesium concentrations, although occasionally administration of intravenous calcium or even dialysis may be required.
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Affiliation(s)
- John Ayuk
- Department of Endocrinology, Queen Elizabeth Hospital, Edgbaston, Birmingham, UK
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Demssie YN, Patel L, Kumar M, Syed AA. Hypomagnesaemia: clinical relevance and management. Br J Hosp Med (Lond) 2014; 75:39-43. [DOI: 10.12968/hmed.2014.75.1.39] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Yared N Demssie
- Consultant Physician, Royal Blackburn Hospital, Blackburn BB2 3HH
| | - Leena Patel
- Foundation Year 2 Trainee, Royal Blackburn Hospital, Blackburn BB2 3HH
| | - Mohit Kumar
- Specialist Trainee in the Department of Endocrinology, Royal Blackburn Hospital, Blackburn BB2 3HH
| | - Akheel A Syed
- Consultant Physician in the Department of Endocrinology, Salford Royal NHS Foundation Trust, Salford and The University of Manchester, Manchester
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Abstract
Hypomagnesaemia is relatively common, with an estimated prevalence in the general population ranging from 2·5% to 15%. It may result from inadequate magnesium intake, increased gastrointestinal or renal loss or redistribution from extracellular to intracellular space. Drug-induced hypomagnesaemia, particularly related to proton pump inhibitor (PPI) therapy, is being increasingly recognized. Most patients with hypomagnesaemia are asymptomatic; symptomatic magnesium depletion is often associated with multiple other biochemical abnormalities, including hypokalaemia, hypocalcaemia and metabolic acidosis. Manifestations of symptomatic hypomagnesaemia most often involve neuromuscular, cardiovascular and metabolic features. Patients with symptomatic hypomagnesaemia should be treated with intravenous magnesium, reserving oral replacement for asymptomatic patients.
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Affiliation(s)
- John Ayuk
- Department of Endocrinology, Queen Elizabeth Hospital, Edgbaston, Birmingham, UK
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