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Gorvin CM. A successful conclusion to the long search for TRPV5 pathogenic variants in monogenic hypercalciuria. Eur J Hum Genet 2024:10.1038/s41431-024-01613-y. [PMID: 38839989 DOI: 10.1038/s41431-024-01613-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2024] [Accepted: 04/16/2024] [Indexed: 06/07/2024] Open
Affiliation(s)
- Caroline M Gorvin
- Institute of Metabolism and Systems Research (IMSR) and Centre for Diabetes, Endocrinology and Metabolism (CEDAM), University of Birmingham, Birmingham, B15 2TT, UK.
- Centre for Membrane Proteins and Receptors (COMPARE), Universities of Birmingham and Nottingham, Birmingham, B15 2TT, UK.
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2
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Guleray Lafci N, van Goor M, Cetinkaya S, van der Wijst J, Acun M, Kurt Colak F, Cetinkaya A, Hoenderop J. Decreased calcium permeability caused by biallelic TRPV5 mutation leads to autosomal recessive renal calcium-wasting hypercalciuria. Eur J Hum Genet 2024:10.1038/s41431-024-01589-9. [PMID: 38528055 DOI: 10.1038/s41431-024-01589-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 01/10/2024] [Accepted: 03/04/2024] [Indexed: 03/27/2024] Open
Abstract
Hypercalciuria is the most common metabolic risk factor in people with kidney stone disease. Its etiology is mostly multifactorial, although monogenetic causes of hypercalciuria have also been described. Despite the increased availability of genetic diagnostic tests, the vast majority of individuals with familial hypercalciuria remain unsolved. In this study, we investigated a consanguineous pedigree with idiopathic hypercalciuria. The proband additionally exhibited severe skeletal deformities and hyperparathyroidism. Whole-exome sequencing of the proband revealed a homozygous ultra-rare variant in TRPV5 (NM_019841.7:c.1792G>A; p.(Val598Met)), which encodes for a renal Ca2+-selective ion channel. The variant segregates with the three individuals with hypercalciuria. The skeletal phenotype unique to the proband was due to an additional pathogenic somatic mutation in GNAS (NM_000516.7:c.601C>T; p.(Arg201Cys)), which leads to polyostotic fibrous dysplasia. The variant in TRPV5 is located in the TRP helix, a characteristic amphipathic helix that is indispensable for the gating movements of TRP channels. Biochemical characterization of the TRPV5 p.(Val598Met) channel revealed a complete loss of Ca2+ transport capability. This defect is caused by reduced expression of the mutant channel, due to misfolding and preferential targeting to the proteasome for degradation. Based on these findings, we conclude that biallelic loss of TRPV5 function causes a novel form of monogenic autosomal recessive hypercalciuria, which we name renal Ca2+-wasting hypercalciuria (RCWH). The recessive inheritance pattern explains the rarity of RCWH and underscores the potential prevalence of RCWH in highly consanguineous populations, emphasizing the importance of exploration of this disorder within such communities.
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Affiliation(s)
- Naz Guleray Lafci
- Hacettepe University, Medical Faculty, Department of Medical Genetics, Ankara, Turkey
- Health Science University, Dr. Sami Ulus Obstetrics and Gynecology, Children Health and Disease Training and Research Hospital, Department of Medical Genetics, Ankara, Turkey
| | - Mark van Goor
- Department of Medical Biosciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Semra Cetinkaya
- Health Science University, Dr. Sami Ulus Obstetrics and Gynecology, Children Health and Disease Training and Research Hospital, Department of Pediatric Endocrinology, Ankara, Turkey
| | - Jenny van der Wijst
- Department of Medical Biosciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Melisa Acun
- Hacettepe University, Institute of Health Sciences, Department of Bioinformatics, Ankara, Turkey
| | - Fatma Kurt Colak
- Health Science University, Dr. Sami Ulus Obstetrics and Gynecology, Children Health and Disease Training and Research Hospital, Department of Medical Genetics, Ankara, Turkey
| | - Arda Cetinkaya
- Hacettepe University, Medical Faculty, Department of Medical Genetics, Ankara, Turkey.
- Hacettepe University, Institute of Health Sciences, Department of Bioinformatics, Ankara, Turkey.
| | - Joost Hoenderop
- Department of Medical Biosciences, Radboud University Medical Center, Nijmegen, The Netherlands.
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3
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Yoon SH, Tang CC, Wein MN. Salt inducible kinases and PTH1R action. VITAMINS AND HORMONES 2022; 120:23-45. [PMID: 35953111 DOI: 10.1016/bs.vh.2022.04.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Parathyroid hormone is a central regulator of calcium homeostasis. PTH protects the organism from hypocalcemia through its actions in bone and kidney. Recent physiologic studies have revealed key target genes for PTH receptor (PTH1R) signaling in these target organs. However, the complete signal transduction cascade used by PTH1R to accomplish these physiologic actions has remained poorly defined. Here we will review recent studies that have defined an important role for salt inducible kinases downstream of PTH1R in bone, cartilage, and kidney. PTH1R signaling inhibits the activity of salt inducible kinases. Therefore, direct SIK inhibitors represent a promising novel strategy to mimic PTH actions using small molecules. Moreover, a detailed understanding of the molecular circuitry used by PTH1R to exert its biologic effects will afford powerful new models to better understand the diverse actions of this important G protein coupled receptor in health and disease.
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Affiliation(s)
- Sung-Hee Yoon
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Cheng-Chia Tang
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Marc N Wein
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States.
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4
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Yelshanskaya MV, Sobolevsky AI. Ligand-Binding Sites in Vanilloid-Subtype TRP Channels. Front Pharmacol 2022; 13:900623. [PMID: 35652046 PMCID: PMC9149226 DOI: 10.3389/fphar.2022.900623] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 04/06/2022] [Indexed: 02/02/2023] Open
Abstract
Vanilloid-subfamily TRP channels TRPV1-6 play important roles in various physiological processes and are implicated in numerous human diseases. Advances in structural biology, particularly the "resolution revolution" in cryo-EM, have led to breakthroughs in molecular characterization of TRPV channels. Structures with continuously improving resolution uncover atomic details of TRPV channel interactions with small molecules and protein-binding partners. Here, we provide a classification of structurally characterized binding sites in TRPV channels and discuss the progress that has been made by structural biology combined with mutagenesis, functional recordings, and molecular dynamics simulations toward understanding of the molecular mechanisms of ligand action. Given the similarity in structural architecture of TRP channels, 16 unique sites identified in TRPV channels may be shared between TRP channel subfamilies, although the chemical identity of a particular ligand will likely depend on the local amino-acid composition. The characterized binding sites and molecular mechanisms of ligand action create a diversity of druggable targets to aid in the design of new molecules for tuning TRP channel function in disease conditions.
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Affiliation(s)
| | - Alexander I. Sobolevsky
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, United States
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5
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van Megen WH, Beggs MR, An SW, Ferreira PG, Lee JJ, Wolf MT, Alexander RT, Dimke H. Gentamicin Inhibits Ca 2+ Channel TRPV5 and Induces Calciuresis Independent of the Calcium-Sensing Receptor-Claudin-14 Pathway. J Am Soc Nephrol 2022; 33:547-564. [PMID: 35022312 PMCID: PMC8975070 DOI: 10.1681/asn.2021030392] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 12/19/2021] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND Treatment with the aminoglycoside antibiotic gentamicin can be associated with severe adverse effects, including renal Ca2+ wasting. The underlying mechanism is unknown but it has been proposed to involve activation of the Ca2+-sensing receptor (CaSR) in the thick ascending limb, which would increase expression of claudin-14 (CLDN14) and limit Ca2+ reabsorption. However, no direct evidence for this hypothesis has been presented. METHODS We studied the effect of gentamicin in vivo using mouse models with impaired Ca2+ reabsorption in the proximal tubule and the thick ascending limb. We used a Cldn14 promoter luciferase reporter assay to study CaSR activation and investigated the effect of gentamicin on activity of the distal nephron Ca2+ channel transient receptor potential vanilloid 5 (TRPV5), as determined by patch clamp in HEK293 cells. RESULTS Gentamicin increased urinary Ca2+ excretion in wild-type mice after acute and chronic administration. This calciuretic effect was unaltered in mice with genetic CaSR overactivation and was present in furosemide-treated animals, whereas the calciuretic effect in Cldn14-/- mice and mice with impaired proximal tubular Ca2+ reabsorption (claudin-2 [CLDN2]-deficient Cldn2-/- mice) was equivalent to that of wild-type mice. In vitro, gentamicin failed to activate the CaSR. In contrast, patch clamp analysis revealed that gentamicin strongly inhibited rabbit and human TRPV5 activity and chronic gentamicin administration downregulated distal nephron Ca2+ transporters. CONCLUSIONS Gentamicin does not cause hypercalciuria via activation of the CaSR-CLDN14 pathway or by interfering with proximal tubular CLDN2-dependent Ca2+ reabsorption. Instead, gentamicin blocks distal Ca2+ reabsorption by direct inhibition of the Ca2+ channel TRPV5. These findings offer new insights into Ca2+ wasting in patients treated with gentamicin.
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Affiliation(s)
- Wouter H. van Megen
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Megan R. Beggs
- Department of Physiology, University of Alberta, Canada,Women and Children's Health Institute, Alberta, Canada
| | - Sung-Wan An
- Department of Pediatrics, Division of Pediatric Nephrology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Patrícia G. Ferreira
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Justin J. Lee
- Department of Physiology, University of Alberta, Canada
| | - Matthias T. Wolf
- Department of Pediatrics, Division of Pediatric Nephrology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - R. Todd Alexander
- Department of Physiology, University of Alberta, Canada,Women and Children's Health Institute, Alberta, Canada,Department of Pediatrics, University of Alberta, Canada
| | - Henrik Dimke
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark .,Department of Nephrology, Odense University Hospital, Denmark
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Hillis DA, Yadgary L, Weinstock GM, Pardo-Manuel de Villena F, Pomp D, Fowler AS, Xu S, Chan F, Garland T. Genetic Basis of Aerobically Supported Voluntary Exercise: Results from a Selection Experiment with House Mice. Genetics 2020; 216:781-804. [PMID: 32978270 PMCID: PMC7648575 DOI: 10.1534/genetics.120.303668] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 09/18/2020] [Indexed: 12/14/2022] Open
Abstract
The biological basis of exercise behavior is increasingly relevant for maintaining healthy lifestyles. Various quantitative genetic studies and selection experiments have conclusively demonstrated substantial heritability for exercise behavior in both humans and laboratory rodents. In the "High Runner" selection experiment, four replicate lines of Mus domesticus were bred for high voluntary wheel running (HR), along with four nonselected control (C) lines. After 61 generations, the genomes of 79 mice (9-10 from each line) were fully sequenced and single nucleotide polymorphisms (SNPs) were identified. We used nested ANOVA with MIVQUE estimation and other approaches to compare allele frequencies between the HR and C lines for both SNPs and haplotypes. Approximately 61 genomic regions, across all somatic chromosomes, showed evidence of differentiation; 12 of these regions were differentiated by all methods of analysis. Gene function was inferred largely using Panther gene ontology terms and KO phenotypes associated with genes of interest. Some of the differentiated genes are known to be associated with behavior/motivational systems and/or athletic ability, including Sorl1, Dach1, and Cdh10 Sorl1 is a sorting protein associated with cholinergic neuron morphology, vascular wound healing, and metabolism. Dach1 is associated with limb bud development and neural differentiation. Cdh10 is a calcium ion binding protein associated with phrenic neurons. Overall, these results indicate that selective breeding for high voluntary exercise has resulted in changes in allele frequencies for multiple genes associated with both motivation and ability for endurance exercise, providing candidate genes that may explain phenotypic changes observed in previous studies.
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Affiliation(s)
- David A Hillis
- Genetics, Genomics, and Bioinformatics Graduate Program, University of California, Riverside, California 92521
| | - Liran Yadgary
- Department of Genetics, University of North Carolina at Chapel Hill, North Carolina 27599
| | - George M Weinstock
- The Jackson Laboratory for Genomic Medicine, Farmington, Connecticut 06032
| | | | - Daniel Pomp
- Department of Genetics, University of North Carolina at Chapel Hill, North Carolina 27599
| | - Alexandra S Fowler
- Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, California 92521
| | - Shizhong Xu
- Department of Botany and Plant Sciences, University of California, Riverside, California 92521
| | - Frank Chan
- Friedrich Miescher Laboratory of the Max Planck Society, 72076 Tübingen, Germany
| | - Theodore Garland
- Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, California 92521
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7
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Abstract
Kidney stone disease (nephrolithiasis) is a common problem that can be associated with alterations in urinary solute composition including hypercalciuria. Studies suggest that the prevalence of monogenic kidney stone disorders, including renal tubular acidosis with deafness, Bartter syndrome, primary hyperoxaluria and cystinuria, in patients attending kidney stone clinics is ∼15%. However, for the majority of individuals, nephrolithiasis has a multifactorial aetiology involving genetic and environmental factors. Nonetheless, the genetic influence on stone formation in these idiopathic stone formers remains considerable and twin studies estimate a heritability of >45% for nephrolithiasis and >50% for hypercalciuria. The contribution of polygenic influences from multiple loci have been investigated by genome-wide association and candidate gene studies, which indicate that a number of genes and molecular pathways contribute to the risk of stone formation. Genetic approaches, studying both monogenic and polygenic factors in nephrolithiasis, have revealed that the following have important roles in the aetiology of kidney stones: transporters and channels; ions, protons and amino acids; the calcium-sensing receptor (a G protein-coupled receptor) signalling pathway; and the metabolic pathways for vitamin D, oxalate, cysteine, purines and uric acid. These advances, which have increased our understanding of the pathogenesis of nephrolithiasis, will hopefully facilitate the future development of targeted therapies for precision medicine approaches in patients with nephrolithiasis.
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Affiliation(s)
- Sarah A Howles
- Nuffield Department of Surgical Sciences, University of Oxford, Oxford, UK.,Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Rajesh V Thakker
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.
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8
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Gorvin CM, Loh NY, Stechman MJ, Falcone S, Hannan FM, Ahmad BN, Piret SE, Reed AA, Jeyabalan J, Leo P, Marshall M, Sethi S, Bass P, Roberts I, Sanderson J, Wells S, Hough TA, Bentley L, Christie PT, Simon MM, Mallon AM, Schulz H, Cox RD, Brown MA, Huebner N, Brown SD, Thakker RV. Mice with a Brd4 Mutation Represent a New Model of Nephrocalcinosis. J Bone Miner Res 2019; 34:1324-1335. [PMID: 30830987 PMCID: PMC6658219 DOI: 10.1002/jbmr.3695] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 01/26/2019] [Accepted: 02/05/2019] [Indexed: 12/30/2022]
Abstract
Nephrolithiasis (NL) and nephrocalcinosis (NC), which comprise renal calcification of the collecting system and parenchyma, respectively, have a multifactorial etiology with environmental and genetic determinants and affect ∼10% of adults by age 70 years. Studies of families with hereditary NL and NC have identified >30 causative genes that have increased our understanding of extracellular calcium homeostasis and renal tubular transport of calcium. However, these account for <20% of the likely genes that are involved, and to identify novel genes for renal calcification disorders, we investigated 1745 12-month-old progeny from a male mouse that had been treated with the chemical mutagen N-ethyl-N-nitrosourea (ENU) for radiological renal opacities. This identified a male mouse with renal calcification that was inherited as an autosomal dominant trait with >80% penetrance in 152 progeny. The calcification consisted of calcium phosphate deposits in the renal papillae and was associated with the presence of the urinary macromolecules osteopontin and Tamm-Horsfall protein, which are features found in Randall's plaques of patients with NC. Genome-wide mapping located the disease locus to a ∼30 Mbp region on chromosome 17A3.3-B3 and whole-exome sequence analysis identified a heterozygous mutation, resulting in a missense substitution (Met149Thr, M149T), in the bromodomain-containing protein 4 (BRD4). The mutant heterozygous (Brd4+/M149T ) mice, when compared with wild-type (Brd4+/+ ) mice, were normocalcemic and normophosphatemic, with normal urinary excretions of calcium and phosphate, and had normal bone turnover markers. BRD4 plays a critical role in histone modification and gene transcription, and cDNA expression profiling, using kidneys from Brd4+/M149T and Brd4+/+ mice, revealed differential expression of genes involved in vitamin D metabolism, cell differentiation, and apoptosis. Kidneys from Brd4+/M149T mice also had increased apoptosis at sites of calcification within the renal papillae. Thus, our studies have established a mouse model, due to a Brd4 Met149Thr mutation, for inherited NC. © 2019 American Society for Bone and Mineral Research.
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Affiliation(s)
- Caroline M Gorvin
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology, and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Nellie Y Loh
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology, and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Michael J Stechman
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology, and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Sara Falcone
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology, and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Fadil M Hannan
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology, and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.,Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, UK
| | - Bushra N Ahmad
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology, and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Sian E Piret
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology, and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Anita Ac Reed
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology, and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Jeshmi Jeyabalan
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology, and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Paul Leo
- Translational Genomics Group, Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Queensland University of Technology (QUT) at Translational Research Institute, Brisbane, Australia
| | - Mhairi Marshall
- Translational Genomics Group, Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Queensland University of Technology (QUT) at Translational Research Institute, Brisbane, Australia
| | - Siddharth Sethi
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council Harwell Institute, Harwell, UK
| | - Paul Bass
- Department of Cellular Pathology, Royal Free Hospital, London, UK
| | - Ian Roberts
- Department of Cellular Pathology, John Radcliffe Hospital, Oxford, UK
| | - Jeremy Sanderson
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council Harwell Institute, Harwell, UK
| | - Sara Wells
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council Harwell Institute, Harwell, UK
| | - Tertius A Hough
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council Harwell Institute, Harwell, UK
| | - Liz Bentley
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council Harwell Institute, Harwell, UK
| | - Paul T Christie
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology, and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Michelle M Simon
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council Harwell Institute, Harwell, UK
| | - Ann-Marie Mallon
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council Harwell Institute, Harwell, UK
| | - Herbert Schulz
- Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | - Roger D Cox
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council Harwell Institute, Harwell, UK
| | - Matthew A Brown
- Translational Genomics Group, Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Queensland University of Technology (QUT) at Translational Research Institute, Brisbane, Australia
| | | | - Steve D Brown
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council Harwell Institute, Harwell, UK
| | - Rajesh V Thakker
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology, and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
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9
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Gorvin CM, Ahmad BN, Stechman MJ, Loh NY, Hough TA, Leo P, Marshall M, Sethi S, Bentley L, Piret SE, Reed A, Jeyabalan J, Christie PT, Wells S, Simon MM, Mallon AM, Schulz H, Huebner N, Brown MA, Cox RD, Brown SD, Thakker RV. An N-Ethyl-N-Nitrosourea (ENU)-Induced Tyr265Stop Mutation of the DNA Polymerase Accessory Subunit Gamma 2 (Polg2) Is Associated With Renal Calcification in Mice. J Bone Miner Res 2019; 34:497-507. [PMID: 30395686 PMCID: PMC6446808 DOI: 10.1002/jbmr.3624] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2018] [Revised: 10/12/2018] [Accepted: 10/28/2018] [Indexed: 12/24/2022]
Abstract
Renal calcification (RCALC) resulting in nephrolithiasis and nephrocalcinosis, which affects ∼10% of adults by 70 years of age, involves environmental and genetic etiologies. Thus, nephrolithiasis and nephrocalcinosis occurs as an inherited disorder in ∼65% of patients, and may be associated with endocrine and metabolic disorders including: primary hyperparathyroidism, hypercalciuria, renal tubular acidosis, cystinuria, and hyperoxaluria. Investigations of families with nephrolithiasis and nephrocalcinosis have identified some causative genes, but further progress is limited as large families are unavailable for genetic studies. We therefore embarked on establishing mouse models for hereditary nephrolithiasis and nephrocalcinosis by performing abdominal X-rays to identify renal opacities in N-ethyl-N-nitrosourea (ENU)-mutagenized mice. This identified a mouse with RCALC inherited as an autosomal dominant trait, designated RCALC type 2 (RCALC2). Genomewide mapping located the Rcalc2 locus to a ∼16-Mbp region on chromosome 11D-E2 and whole-exome sequence analysis identified a heterozygous mutation in the DNA polymerase gamma-2, accessory subunit (Polg2) resulting in a nonsense mutation, Tyr265Stop (Y265X), which co-segregated with RCALC2. Kidneys of mutant mice (Polg2+/Y265X ) had lower POLG2 mRNA and protein expression, compared to wild-type littermates (Polg2+/+ ). The Polg2+/Y265X and Polg2+/+ mice had similar plasma concentrations of sodium, potassium, calcium, phosphate, chloride, urea, creatinine, glucose, and alkaline phosphatase activity; and similar urinary fractional excretion of calcium, phosphate, oxalate, and protein. Polg2 encodes the minor subunit of the mitochondrial DNA (mtDNA) polymerase and the mtDNA content in Polg2+/Y265X kidneys was reduced compared to Polg2+/+ mice, and cDNA expression profiling revealed differential expression of 26 genes involved in several biological processes including mitochondrial DNA function, apoptosis, and ubiquitination, the complement pathway, and inflammatory pathways. In addition, plasma of Polg2+/Y265X mice, compared to Polg2+/+ littermates had higher levels of reactive oxygen species. Thus, our studies have identified a mutant mouse model for inherited renal calcification associated with a Polg2 nonsense mutation. © 2018 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals, Inc.
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Affiliation(s)
- Caroline M Gorvin
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Bushra N Ahmad
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Michael J Stechman
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Nellie Y Loh
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Tertius A Hough
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council, Harwell, UK
| | - Paul Leo
- Translational Genomics Group, Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Queensland University of Technology at Translational Research Institute, Brisbane, Australia
| | - Mhairi Marshall
- Translational Genomics Group, Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Queensland University of Technology at Translational Research Institute, Brisbane, Australia
| | - Siddharth Sethi
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council, Harwell, UK
| | - Liz Bentley
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council, Harwell, UK
| | - Sian E Piret
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Anita Reed
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Jeshmi Jeyabalan
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Paul T Christie
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Sara Wells
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council, Harwell, UK
| | - Michelle M Simon
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council, Harwell, UK
| | - Ann-Marie Mallon
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council, Harwell, UK
| | - Herbert Schulz
- Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | | | - Matthew A Brown
- Translational Genomics Group, Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Queensland University of Technology at Translational Research Institute, Brisbane, Australia
| | - Roger D Cox
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council, Harwell, UK
| | - Steve D Brown
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council, Harwell, UK
| | - Rajesh V Thakker
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
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10
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Renal ischemia-reperfusion injury impairs renal calcium, magnesium, and phosphate handling in mice. Pflugers Arch 2019; 471:901-914. [PMID: 30685787 DOI: 10.1007/s00424-019-02255-6] [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: 10/29/2018] [Revised: 01/04/2019] [Accepted: 01/10/2019] [Indexed: 01/04/2023]
Abstract
Fibroblast growth factor 23 (FGF23) levels are elevated in patients with acute kidney injury (AKI). The consequences on renal Ca2+, Mg2+, and Pi regulatory mechanisms are unknown. We hypothesized that renal ischemia-reperfusion (I/R) injury alters the expression of important renal Ca2+, Mg2+, and Pi transport proteins. I/R injury was induced in male C57BL/6 mice by clamping both renal arteries for 27 min. Mice were investigated 18 h later. The mRNA and protein levels of renal Ca2+, Mg2+, and Pi transport proteins were measured by RT-qPCR and western blot analysis. I/R injury-induced hyperphosphatemia and hypermagnesemia were paralleled by a decrease in glomerular filtration rate and an increase in the fractional excretion of Ca2+, Mg2+, and Pi. I/R injury affected the fibroblast growth factor 23 (FGF23)-klotho-vitamin D axis by increasing plasma levels of FGF23 and downregulation of renal klotho expression. Plasma levels of PTH and 1,25-dihydroxyvitamin D3 were unchanged. Further, downregulation of key genes for paracellular reabsorption of Ca2+ and Mg2+ (claudin (Cldn)2, Cldn10b, Cldn16, Cldn19) and for active transcellular transport of Ca2+, Mg2+, and Pi (calbindin-D28K, Ncx1, Pmca4, Cnnm2, Trpm7, NaPi-2a, and NaPi-2c) was observed. However, renal expression of Trpv5 and Trpv6 was increased. In vitro studies support a direct effect of proinflammatory cytokines on the mRNA expression of Cldn16, Cldn19, and Trpv6. Our findings indicate that renal I/R injury increases FGF23 blood levels independent of PTH and 1,25-dihydroxyvitamin D3. This increase is associated with hypermagnesemia, hyperphosphatemia, and increased or decreased expression of specific renal Ca2+, Mg2+, and Pi transporters, respectively.
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11
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Liu J, Zhang L, Feng L, Xu M, Gao Y, Zhou P, Yu Z, Zhu B, An Y, Zhang H. Association between single nucleotide polymorphism (rs4252424) in TRPV5 calcium channel gene and lead poisoning in Chinese workers. Mol Genet Genomic Med 2019; 7:e562. [PMID: 30666830 PMCID: PMC6418352 DOI: 10.1002/mgg3.562] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 11/27/2018] [Accepted: 12/13/2018] [Indexed: 12/22/2022] Open
Abstract
Background Lead (Pb) is broadly used in various industries and causes irreversible damage to human tissues, organs, and systems. Studies have revealed that lead exerts toxic effects via interfering with calcium channel. Methods In the present study, we investigated whether single nucleotide polymorphisms (SNPs) in TRPV5, a calcium channel‐related gene, were associated with lead exposure susceptibility. By using TaqMan SNP genotyping, we performed genotyping of eight TRPV5 tag‐SNPs in 1,130 lead‐exposed Chinese workers with similar lead exposure level. Results Single nucleotide polymorphism rs4252424 was significantly associated with lead susceptibility, measured by blood lead level (BLL) (β = −0.069, plinear = 0.029). However, there was no significant association between any other seven SNPs and BLL. The further expression Quantitative Trait Loci displayed that CC genotype of rs4252424 is significant associated with higher BLL than CT (p < 0.0001). Conclusion We conclude that SNP rs4252424 has the potential to evaluate lead susceptibility in the Chinese occupational population, and further enhance lead exposure prevention and intervention.
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Affiliation(s)
- Jiting Liu
- Department of Toxicology, School of Public Health, Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases, Medical College of Soochow University, Suzhou, China
| | - Li Zhang
- Department of Occupational Disease Prevention, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China.,Public Health Research Institute of Jiangsu Province, Nanjing, China
| | - Lixia Feng
- Wuzhong City Center for Disease Control and Prevention, Wuzhong, China
| | - Ming Xu
- Department of Occupational Disease Prevention, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China.,Public Health Research Institute of Jiangsu Province, Nanjing, China
| | - Yue Gao
- Department of Occupational Disease Prevention, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China.,Public Health Research Institute of Jiangsu Province, Nanjing, China
| | - Peng Zhou
- Department of Occupational Disease Prevention, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China.,Public Health Research Institute of Jiangsu Province, Nanjing, China
| | - Zhengmin Yu
- Department of Occupational Disease Prevention, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China.,Public Health Research Institute of Jiangsu Province, Nanjing, China
| | - Baoli Zhu
- Nanjing Medical University, Nanjing, China
| | - Yan An
- Department of Toxicology, School of Public Health, Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases, Medical College of Soochow University, Suzhou, China
| | - Hengdong Zhang
- Department of Occupational Disease Prevention, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China.,Public Health Research Institute of Jiangsu Province, Nanjing, China
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12
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Meurer M, Höcherl K. Endotoxaemia differentially regulates the expression of renal Ca 2+ transport proteins in mice. Acta Physiol (Oxf) 2019; 225:e13175. [PMID: 30133162 DOI: 10.1111/apha.13175] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 08/17/2018] [Accepted: 08/18/2018] [Indexed: 12/16/2022]
Abstract
AIM Alterations in parathyroid hormone (PTH) and/or vitamin D signalling are frequently reported in patients with sepsis. The consequences on renal and intestinal Ca2+ and Pi regulatory mechanisms are still unclear. We hypothesized that endotoxaemia alters the expression of important renal and intestinal Ca2+ and Pi transport proteins. METHODS Male C57BL/6 mice were treated with lipopolysaccharide (LPS; 3 mg/kg; i.p.). The mRNA and protein levels of renal and intestinal Ca2+ and Pi transport proteins were measured by RT-qPCR, immunohistochemistry and western blot analysis. RESULTS Lipopolysaccharide-induced hypocalcaemia and hyperphosphataemia was paralleled by a decrease in glomerular filtration rate and urinary excretion of Ca2+ and Pi . Endotoxaemia augmented plasma levels of PTH and affected the fibroblast growth factor 23 (FGF23)-klotho-vitamin D axis by increasing plasma levels of FGF23 and downregulation of renal klotho expression. Renal expression of CYP27b1 and plasma levels of 1,25-dihydroxyvitamin D3 were increased in response to LPS. Endotoxaemia augmented the renal expression of TRPV5, TRPV6 and PiT1, whereas the renal expression of calbindin-D28K , NCX1, NaPi -2a and NaPi -2c were decreased. Incubation of primary distal tubule cells with LPS increased TRPV6 mRNA levels. Furthermore, LPS decreased the intestinal expression of TRPV6, calbindin-D9K and of NaPi -2b. CONCLUSION Our findings indicate that endotoxaemia is associated with hypocalcaemia and hyperphosphataemia and a disturbed FGF23-klotho-vitamin D signaling. Further, LPS-induced acute kidney injury was accompanied by an increased or decreased expression of specific renal and intestinal Ca2+ and Pi transporters respectively. It seems unlikely that LPS-induced hypocalcaemia is due to renal loss of Ca2+ .
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Affiliation(s)
- Manuel Meurer
- Institute of Experimental and Clinical Pharmacology and Toxicology; Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU); Erlangen Germany
| | - Klaus Höcherl
- Institute of Experimental and Clinical Pharmacology and Toxicology; Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU); Erlangen Germany
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13
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Wang L, Holmes RP, Peng JB. Modeling the structural and dynamical changes of the epithelial calcium channel TRPV5 caused by the A563T variation based on the structure of TRPV6. J Biomol Struct Dyn 2018; 37:3506-3512. [PMID: 30175942 DOI: 10.1080/07391102.2018.1518790] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
TRPV5, transient receptor potential cation channel vanilloid subfamily member 5, is an epithelial Ca2+ channel that plays a key role in the active Ca2+ reabsorption process in the kidney. A single nucleotide polymorphism (SNP) rs4252499 in the TRPV5 gene results in an A563T variation in the sixth transmembrane (TM) domain of TRPV5. Our previous study indicated that this variation increases the Ca2+ transport function of TRPV5. To understand the molecular mechanism, a model of TRPV5 was established based on the newly deposited structure of TRPV6 that has 83.1% amino acid identity with TRPV5 in the modeled region. Computational simulations were performed to study the structural and dynamical differences between the TRPV5 variants with A563 and T563. Consistent with the TRPV1-based simulation, the results indicate that the A563T variation increases the contacts between residues 563 and V540, which is one residue away from the key residue D542 in the Ca2+-selective filter. The variation enhanced the stability of the secondary structure of the pore region, decreased the fluctuation of residues around residue 563, and reduced correlated and anti-correlated motion between monomers. Furthermore, the variation increases the pore radius at the selective filter. These findings were confirmed using simulations based on the recently determined structure of rabbit TRPV5. The simulation results provide an explanation for the observation of enhanced Ca2+ influx in TRPV5 caused by the A563T variation. The A563T variation is an interesting example of how a residue distant from the Ca2+-selective filter influences the Ca2+ transport function of the TRPV5 channel. Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Lingyun Wang
- a Department of Medicine, Division of Nephrology , Nephrology Research and Training Center, University of Alabama at Birmingham , Birmingham , AL , USA
| | - Ross P Holmes
- b Department of Urology , University of Alabama at Birmingham , Birmingham , AL , USA
| | - Ji-Bin Peng
- a Department of Medicine, Division of Nephrology , Nephrology Research and Training Center, University of Alabama at Birmingham , Birmingham , AL , USA.,b Department of Urology , University of Alabama at Birmingham , Birmingham , AL , USA
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14
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Palsson R, Indridason OS, Edvardsson VO, Oddsson A. Genetics of common complex kidney stone disease: insights from genome-wide association studies. Urolithiasis 2018; 47:11-21. [PMID: 30523390 DOI: 10.1007/s00240-018-1094-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 11/08/2018] [Indexed: 12/29/2022]
Abstract
Kidney stone disease is a common disorder in Western countries that is associated with significant suffering, morbidity, and cost for the healthcare system. Numerous studies have demonstrated familial aggregation of nephrolithiasis and a twin study estimated the heritability to be 56%. Over the past decade, genome-wide association studies have uncovered several sequence variants that confer increased risk of common complex kidney stone disease. The first reported variants were observed at the CLDN14 locus in the Icelandic population. This finding has since been replicated in other populations. The CLDN14 gene is expressed in tight junctions of the thick ascending limb of the loop of Henle, where the protein is believed to play a role in regulation of calcium transport. More recent studies have uncovered variants at the ALPL, SLC34A1, CASR, and TRPV5 loci, the first two genes playing a role in renal handling of phosphate, while the latter two are involved in calcium homeostasis. Although genetic data have provided insights into the molecular basis of kidney stone disease, much remains to be learned about the contribution of genetic factors to stone formation. Nevertheless, the progress made in recent years indicates that exciting times lie ahead in genetic research on kidney stone disease.
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Affiliation(s)
- Runolfur Palsson
- Faculty of Medicine, School of Health Sciences, University of Iceland, Reykjavik, Iceland. .,Division of Nephrology, Internal Medicine Services, Landspitali-The National University Hospital of Iceland, Reykjavik, Iceland.
| | - Olafur S Indridason
- Division of Nephrology, Internal Medicine Services, Landspitali-The National University Hospital of Iceland, Reykjavik, Iceland
| | - Vidar O Edvardsson
- Faculty of Medicine, School of Health Sciences, University of Iceland, Reykjavik, Iceland.,Children's Medical Center, Landspitali-The National University Hospital of Iceland, Reykjavik, Iceland
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15
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Abstract
Hypocalcemia and hyperphosphatemia are the pathognomonic biochemical features of hypoparathyroidism, and result directly from lack of parathyroid hormone (PTH) action on the kidney. In the absence of PTH action, the renal mechanisms transporting calcium and phosphate reabsorption deregulate, resulting in hypocalcemia and hyperphosphatemia. Circulating calcium negatively regulates PTH secretion. Hypocalcemia causes neuromuscular disturbances ranging from epilepsy and tetany to mild paresthesia. Circulating phosphate concentration does not directly regulate PTH secretion. Hyperphosphatemia is subclinical, but chronically promotes ectopic mineralization disease. Vitamin D-thiazide treatment leads to ectopic mineralization and renal damage. PTH treatment has the potential for fewer side effects.
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Affiliation(s)
- Munro Peacock
- Department of Medicine, Division of Endocrinology, Indiana University School of Medicine, 1120 West Michigan Street Cl 365, Indianapolis, IN 46202, USA.
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16
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Howles SA, Hannan FM, Gorvin CM, Piret SE, Paudyal A, Stewart M, Hough TA, Nesbit MA, Wells S, Brown SD, Cox RD, Thakker RV. Cinacalcet corrects hypercalcemia in mice with an inactivating Gα11 mutation. JCI Insight 2017; 2:96540. [PMID: 29046478 PMCID: PMC5846897 DOI: 10.1172/jci.insight.96540] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 09/19/2017] [Indexed: 11/17/2022] Open
Abstract
Loss-of-function mutations of GNA11, which encodes G-protein subunit α11 (Gα11), a signaling partner for the calcium-sensing receptor (CaSR), result in familial hypocalciuric hypercalcemia type 2 (FHH2). FHH2 is characterized by hypercalcemia, inappropriately normal or raised parathyroid hormone (PTH) concentrations, and normal or low urinary calcium excretion. A mouse model for FHH2 that would facilitate investigations of the in vivo role of Gα11 and the evaluation of calcimimetic drugs, which are CaSR allosteric activators, is not available. We therefore screened DNA from > 10,000 mice treated with the chemical mutagen N-ethyl-N-nitrosourea (ENU) for GNA11 mutations and identified a Gα11 variant, Asp195Gly (D195G), which downregulated CaSR-mediated intracellular calcium signaling in vitro, consistent with it being a loss-of-function mutation. Treatment with the calcimimetic cinacalcet rectified these signaling responses. In vivo studies showed mutant heterozygous (Gna11+/195G) and homozygous (Gna11195G/195G) mice to be hypercalcemic with normal or increased plasma PTH concentrations and normal urinary calcium excretion. Cinacalcet (30mg/kg orally) significantly reduced plasma albumin–adjusted calcium and PTH concentrations in Gna11+/195G and Gna11195G/195G mice. Thus, our studies have established a mouse model with a germline loss-of-function Gα11 mutation that is representative for FHH2 in humans and demonstrated that cinacalcet can correct the associated abnormalities of plasma calcium and PTH. Cinacalcet corrects hypercalcemia in a mouse model for familial hypocalciuric hypercalcemia type 2 (FHH2) caused by a germline loss-of-function G-protein subunit α11 (Gα11) mutation, Asp195Gly.
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Affiliation(s)
- Sarah A Howles
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Fadil M Hannan
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom.,Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom
| | - Caroline M Gorvin
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Sian E Piret
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Anju Paudyal
- Mammalian Genetics Unit and Mary Lyon Centre, Medical Research Council (MRC) Harwell Institute, Harwell Science and Innovation Campus, United Kingdom
| | - Michelle Stewart
- Mammalian Genetics Unit and Mary Lyon Centre, Medical Research Council (MRC) Harwell Institute, Harwell Science and Innovation Campus, United Kingdom
| | - Tertius A Hough
- Mammalian Genetics Unit and Mary Lyon Centre, Medical Research Council (MRC) Harwell Institute, Harwell Science and Innovation Campus, United Kingdom
| | - M Andrew Nesbit
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom.,Biomedical Sciences Research Institute, Ulster University, Coleraine, United Kingdom
| | - Sara Wells
- Mammalian Genetics Unit and Mary Lyon Centre, Medical Research Council (MRC) Harwell Institute, Harwell Science and Innovation Campus, United Kingdom
| | - Stephen Dm Brown
- Mammalian Genetics Unit and Mary Lyon Centre, Medical Research Council (MRC) Harwell Institute, Harwell Science and Innovation Campus, United Kingdom
| | - Roger D Cox
- Mammalian Genetics Unit and Mary Lyon Centre, Medical Research Council (MRC) Harwell Institute, Harwell Science and Innovation Campus, United Kingdom
| | - Rajesh V Thakker
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
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17
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Wang L, Holmes RP, Peng JB. The L530R variation associated with recurrent kidney stones impairs the structure and function of TRPV5. Biochem Biophys Res Commun 2017; 492:362-367. [PMID: 28847730 DOI: 10.1016/j.bbrc.2017.08.102] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 08/25/2017] [Indexed: 01/17/2023]
Abstract
TRPV5 is a Ca2+-selective channel that plays a key role in the reabsorption of Ca2+ ions in the kidney. Recently, a rare L530R variation (rs757494578) of TRPV5 was found to be associated with recurrent kidney stones in a founder population. However, it was unclear to what extent this variation alters the structure and function of TRPV5. To evaluate the function and expression of the TRPV5 variant, Ca2+ uptake in Xenopus oocytes and western blot analysis were performed. The L530R variation abolished the Ca2+ uptake activity of TRPV5 in Xenopus oocytes. The variant protein was expressed with drastic reduction in complex glycosylation. To assess the structural effects of this L530R variation, TRPV5 was modeled based on the crystal structure of TRPV6 and molecular dynamics simulations were carried out. Simulation results showed that the L530R variation disrupts the hydrophobic interaction between L530 and L502, damaging the secondary structure of transmembrane domain 5. The variation also alters its interaction with membrane lipid molecules. Compared to the electroneutral L530, the positively charged R530 residue shifts the surface electrostatic potential towards positive. R530 is attracted to the negatively charged phosphate group rather than the hydrophobic carbon atoms of membrane lipids. This shifts the pore helix where R530 is located and the D542 residue in the Ca2+-selective filter towards the surface of the membrane. These alterations may lead to misfolding of TRPV5, reduction in translocation of the channel to the plasma membrane and/or impaired Ca2+ transport function of the channel, and ultimately disrupt TRPV5-mediated Ca2+ reabsorption.
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Affiliation(s)
- Lingyun Wang
- Division of Nephrology, Department of Medicine, Nephrology Research and Training Center, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Ross P Holmes
- Department of Urology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Ji-Bin Peng
- Division of Nephrology, Department of Medicine, Nephrology Research and Training Center, University of Alabama at Birmingham, Birmingham, AL 35294, USA; Department of Urology, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
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18
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Gorvin CM, Rogers A, Stewart M, Paudyal A, Hough TA, Teboul L, Wells S, Brown SD, Cox RD, Thakker RV. N-ethyl-N-nitrosourea-Induced Adaptor Protein 2 Sigma Subunit 1 ( Ap2s1) Mutations Establish Ap2s1 Loss-of-Function Mice. JBMR Plus 2017; 1:3-15. [PMID: 29479578 PMCID: PMC5824975 DOI: 10.1002/jbm4.10001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The adaptor protein‐2 sigma subunit (AP2σ), encoded by AP2S1, forms a heterotetrameric complex, with AP2α, AP2β, and AP2μ subunits, that is pivotal for clathrin‐mediated endocytosis, and AP2σ loss‐of‐function mutations impair internalization of the calcium‐sensing receptor (CaSR), a G‐protein–coupled receptor, and cause familial hypocalciuric hypercalcemia type‐3 (FHH3). Mice with AP2σ mutations that would facilitate investigations of the in vivo role of AP2σ, are not available, and we therefore embarked on establishing such mice. We screened >10,000 mice treated with the mutagen N‐ethyl‐N‐nitrosourea (ENU) for Ap2s1 mutations and identified 5 Ap2s1 variants, comprising 2 missense (Tyr20Asn and Ile123Asn) and 3 intronic base substitutions, one of which altered the invariant donor splice site dinucleotide gt to gc. Three‐dimensional modeling and cellular expression of the missense Ap2s1 variants did not reveal them to alter AP2σ structure or CaSR‐mediated signaling, but investigation of the donor splice site variant revealed it to result in an in‐frame deletion of 17 evolutionarily conserved amino acids (del17) that formed part of the AP2σ α1‐helix, α1‐β3 loop, and β3 strand. Heterozygous mutant mice (Ap2s1+/del17) were therefore established, and these had AP2σ haplosufficiency but were viable with normal appearance and growth. Ap2s1+/del17 mice, when compared with Ap2s1+/+ mice, also had normal plasma concentrations of calcium, phosphate, magnesium, creatinine, urea, sodium, potassium, and alkaline phosphatase activity; normal urinary fractional excretion of calcium, phosphate, sodium, and potassium; and normal plasma parathyroid hormone (PTH) and 1,25‐dihydroxyvitamin D (1,25(OH)2) concentrations. However, homozygous Ap2s1del17/del17 mice were non‐viable and died between embryonic days 3.5 and 9.5 (E3.5–9.5), thereby indicating that AP2σ likely has important roles at the embryonic patterning stages and organogenesis of the heart, thyroid, liver, gut, lungs, pancreas, and neural systems. Thus, our studies have established a mutant mouse model that is haplosufficient for AP2σ. © 2017 The Authors. JBMR Plus is published by Wiley Periodicals, Inc. on behalf of the American Society for Bone and Mineral Research.
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Affiliation(s)
- Caroline M Gorvin
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford Centre for Diabetes, Endocrinology, and Metabolism (OCDEM), Churchill Hospital, Oxford, UK
| | - Angela Rogers
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford Centre for Diabetes, Endocrinology, and Metabolism (OCDEM), Churchill Hospital, Oxford, UK
| | - Michelle Stewart
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council Harwell Institute, Harwell Campus, Oxfordshire, UK
| | - Anju Paudyal
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council Harwell Institute, Harwell Campus, Oxfordshire, UK
| | - Tertius A Hough
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council Harwell Institute, Harwell Campus, Oxfordshire, UK
| | - Lydia Teboul
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council Harwell Institute, Harwell Campus, Oxfordshire, UK
| | - Sara Wells
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council Harwell Institute, Harwell Campus, Oxfordshire, UK
| | - Steve Dm Brown
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council Harwell Institute, Harwell Campus, Oxfordshire, UK
| | - Roger D Cox
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council Harwell Institute, Harwell Campus, Oxfordshire, UK
| | - Rajesh V Thakker
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford Centre for Diabetes, Endocrinology, and Metabolism (OCDEM), Churchill Hospital, Oxford, UK
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19
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Kumar S, Singh U, Goswami C, Singru PS. Transient receptor potential vanilloid 5 (TRPV5), a highly Ca 2+ -selective TRP channel in the rat brain: relevance to neuroendocrine regulation. J Neuroendocrinol 2017; 29. [PMID: 28235149 DOI: 10.1111/jne.12466] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 02/21/2017] [Accepted: 02/21/2017] [Indexed: 11/28/2022]
Abstract
Recent studies suggest an important role for transient receptor potential vanilloid (TRPV) ion channels in neural and neuroendocrine regulation. The TRPV subfamily consists of six members: TRPV1-6. While the neuroanatomical and functional correlates of TRPV1-4 have been studied extensively, relevant information about TRPV5 and TRPV6, which are highly selective for Ca2+ , is limited. We detected TRPV5 mRNA expression in the olfactory bulb, cortex, hypothalamus, hippocampus, midbrain, brainstem and cerebellum of the rat. TRPV5-immunoreactive neurones were conspicuously seen in the hypothalamic paraventricular (PVN), supraoptic (SON), accessory neurosecretory (ANS), supraoptic nucleus, retrochiasmatic part (SOR), arcuate (ARC) and medial tuberal nuclei, hippocampus, midbrain, brainstem and cerebellum. Glial cells also showed TRPV5-immunoreactivity. To test the neuroendocrine relevance of TRPV5, we focused on vasopressin, oxytocin and cocaine- and amphetamine-regulated transcript (CART) as representative candidate markers with which TRPV5 may co-exist. In the hypothalamic neurones, co-expression of TRPV5 was observed with vasopressin (PVN: 50.73±3.82%; SON: 75.91±2.34%; ANS: 49.12±4.28%; SOR: 100%) and oxytocin (PVN: 6.88±1.21; SON: 63.34±5.69%; ANS: 20.4±4.14; SOR: 86.5±1.74%). While ARC neurones express oestrogen receptors, 17β-oestradiol regulates TRPV5, as well as CART neurones and astrocytes, in the ARC. Furthermore, ARC CART neurones are known to project to the preoptic area, and innervate and regulate GnRH neurones. Using double-immunofluorescence, glial fibrillary acidic protein-labelled astrocytes and the majority of CART neurones in the ARC showed TRPV5-immunoreactivity. Following iontophoresis of retrograde neuronal tracer, cholera toxin β (CtB) into the anteroventral periventricular nucleus and median preoptic nucleus, retrograde accumulation of CtB was observed in most TRPV5-equipped ARC CART neurones. Next, we determined the response of TRPV5-elements in the ARC during the oestrous cycle. Compared to pro-oestrus, a significant increase (P<.001) in the percentage of TRPV5-expressing CART neurones was observed during oestrus, metoestrus, and dioestrus. TRPV5-immunoreactivity in the astrocytes, however, showed a significant increase during metoestrus and dioestrus. We suggest that the TRPV5 ion channel may serve as an important regulator of neural and neuroendocrine pathways in the brain.
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Affiliation(s)
- S Kumar
- School of Biological Sciences, National Institute of Science Education and Research (NISER), Bhubaneswar, India
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai, India
| | - U Singh
- School of Biological Sciences, National Institute of Science Education and Research (NISER), Bhubaneswar, India
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai, India
| | - C Goswami
- School of Biological Sciences, National Institute of Science Education and Research (NISER), Bhubaneswar, India
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai, India
| | - P S Singru
- School of Biological Sciences, National Institute of Science Education and Research (NISER), Bhubaneswar, India
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai, India
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20
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Suzuki Y, Watanabe M, Saito CT, Tominaga M. Expression of the TRPM6 in mouse placental trophoblasts; potential role in maternal-fetal calcium transport. J Physiol Sci 2017; 67:151-162. [PMID: 27043350 PMCID: PMC10717052 DOI: 10.1007/s12576-016-0449-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 03/20/2016] [Indexed: 12/14/2022]
Abstract
The placenta is required to transport calcium (Ca2+) from mother to fetus during fetal bone mineralization. In an attempt to clarify the molecular basis of Ca2+ entry for this transport, we identified TRPM6 as a candidate for apical Ca2+ entry pathway. TRPM6 mRNA increased during the last 4 days of pregnancy, coinciding with fetal bone mineralization in mice. TRPM6 mRNA and protein was localized in the trophoblasts in labyrinth where the maternal-fetal Ca2+ transport occurs. In patch-clamp recordings, we observed TRPM6/TRPM7-like currents in mouse trophoblasts after starting fetal bone mineralization but not before mineralization. Plasma membrane Ca2+ permeability was significantly increased in TRPM6/TRPM7 expressed HEK293 cells under physiological Mg2+ and ATP concentration but not in TRPM6 or TRPM7 homomer-expressing cells. These results suggest that TRPM6 is functionally expressed in mouse placental trophoblasts, implicating in maternal-fetal Ca2+ transport likely with TRPM7, which might enable to sustain fetal bone mineralization.
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Affiliation(s)
- Yoshiro Suzuki
- Division of Cell Signaling, Okazaki Institute for Integrative Bioscience (National Institute for Physiological Sciences), National Institutes of Natural Sciences, Okazaki, 444-8787, Japan.
- Department of Physiological Sciences, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, 444-8787, Japan.
| | - Masaki Watanabe
- Division of Cell Signaling, Okazaki Institute for Integrative Bioscience (National Institute for Physiological Sciences), National Institutes of Natural Sciences, Okazaki, 444-8787, Japan
- Department of Renal and Urologic Surgery, Asahikawa Medical University, Asahikawa, 078-8510, Japan
| | - Claire T Saito
- Division of Cell Signaling, Okazaki Institute for Integrative Bioscience (National Institute for Physiological Sciences), National Institutes of Natural Sciences, Okazaki, 444-8787, Japan
| | - Makoto Tominaga
- Division of Cell Signaling, Okazaki Institute for Integrative Bioscience (National Institute for Physiological Sciences), National Institutes of Natural Sciences, Okazaki, 444-8787, Japan.
- Department of Physiological Sciences, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, 444-8787, Japan.
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21
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Sayer JA. Progress in Understanding the Genetics of Calcium-Containing Nephrolithiasis. J Am Soc Nephrol 2016; 28:748-759. [PMID: 27932479 DOI: 10.1681/asn.2016050576] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Renal stone disease is a frequent condition, causing a huge burden on health care systems globally. Calcium-based calculi account for around 75% of renal stone disease and the incidence of these calculi is increasing, suggesting environmental and dietary factors are acting upon a preexisting genetic background. The familial nature and significant heritability of stone disease is known, and recent genetic studies have successfully identified genes that may be involved in renal stone formation. The detection of monogenic causes of renal stone disease has been made more feasible by the use of high-throughput sequencing technologies and has also facilitated the discovery of novel monogenic causes of stone disease. However, the majority of calcium stone formers remain of undetermined genotype. Genome-wide association studies and candidate gene studies implicate a series of genes involved in renal tubular handling of lithogenic substrates, such as calcium, oxalate, and phosphate, and of inhibitors of crystallization, such as citrate and magnesium. Additionally, expression profiling of renal tissues from stone formers provides a novel way to explore disease pathways. New animal models to explore these recently-identified mechanisms and therapeutic interventions are being tested, which hopefully will provide translational insights to stop the growing incidence of nephrolithiasis.
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Affiliation(s)
- John A Sayer
- Institute of Genetic Medicine, International Centre for Life, Newcastle University, Newcastle, United Kingdom
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22
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Vasudevan V, Samson P, Smith AD, Okeke Z. The genetic framework for development of nephrolithiasis. Asian J Urol 2016; 4:18-26. [PMID: 29264202 PMCID: PMC5730897 DOI: 10.1016/j.ajur.2016.11.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 07/12/2016] [Indexed: 11/24/2022] Open
Abstract
Over 1%–15% of the population worldwide is affected by nephrolithiasis, which remains the most common and costly disease that urologists manage today. Identification of at-risk individuals remains a theoretical and technological challenge. The search for monogenic causes of stone disease has been largely unfruitful and a technological challenge; however, several candidate genes have been implicated in the development of nephrolithiasis. In this review, we will review current data on the genetic inheritance of stone disease, as well as investigate the evolving role of genetic analysis and counseling in the management of nephrolithiasis.
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Affiliation(s)
- Vinaya Vasudevan
- Smith Institute for Urology, Hofstra Northwell School of Medicine, Lake Success, NY, USA
| | - Patrick Samson
- Smith Institute for Urology, Hofstra Northwell School of Medicine, Lake Success, NY, USA
| | - Arthur D Smith
- Smith Institute for Urology, Hofstra Northwell School of Medicine, Lake Success, NY, USA
| | - Zeph Okeke
- Smith Institute for Urology, Hofstra Northwell School of Medicine, Lake Success, NY, USA
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23
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Moor MB, Bonny O. Ways of calcium reabsorption in the kidney. Am J Physiol Renal Physiol 2016; 310:F1337-50. [PMID: 27009338 DOI: 10.1152/ajprenal.00273.2015] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 03/17/2016] [Indexed: 11/22/2022] Open
Abstract
The role of the kidney in calcium homeostasis has been reshaped from a classic view in which the kidney was regulated by systemic calcitropic hormones such as vitamin D3 or parathyroid hormone to an organ actively taking part in the regulation of calcium handling. With the identification of the intrinsic renal calcium-sensing receptor feedback system, the regulation of paracellular calcium transport involving claudins, and new paracrine regulators such as klotho, the kidney has emerged as a crucial modulator not only of calciuria but also of calcium homeostasis. This review summarizes recent molecular and endocrine contributors to renal calcium handling and highlights the tight link between calcium and sodium reabsorption in the kidney.
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Affiliation(s)
- Matthias B Moor
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland; and
| | - Olivier Bonny
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland; and Service of Nephrology, Department of Medicine, Lausanne University Hospital, Lausanne, Switzerland
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24
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Oddsson A, Sulem P, Helgason H, Edvardsson VO, Thorleifsson G, Sveinbjörnsson G, Haraldsdottir E, Eyjolfsson GI, Sigurdardottir O, Olafsson I, Masson G, Holm H, Gudbjartsson DF, Thorsteinsdottir U, Indridason OS, Palsson R, Stefansson K. Common and rare variants associated with kidney stones and biochemical traits. Nat Commun 2015; 6:7975. [PMID: 26272126 PMCID: PMC4557269 DOI: 10.1038/ncomms8975] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 07/02/2015] [Indexed: 01/07/2023] Open
Abstract
Kidney stone disease is a complex disorder with a strong genetic component. We conducted a genome-wide association study of 28.3 million sequence variants detected through whole-genome sequencing of 2,636 Icelanders that were imputed into 5,419 kidney stone cases, including 2,172 cases with a history of recurrent kidney stones, and 279,870 controls. We identify sequence variants associating with kidney stones at ALPL (rs1256328[T], odds ratio (OR)=1.21, P=5.8 × 10−10) and a suggestive association at CASR (rs7627468[A], OR=1.16, P=2.0 × 10−8). Focusing our analysis on coding sequence variants in 63 genes with preferential kidney expression we identify two rare missense variants SLC34A1 p.Tyr489Cys (OR=2.38, P=2.8 × 10−5) and TRPV5 p.Leu530Arg (OR=3.62, P=4.1 × 10−5) associating with recurrent kidney stones. We also observe associations of the identified kidney stone variants with biochemical traits in a large population set, indicating potential biological mechanism. Kidney stone formation is influenced by genetic factors and recurrent stone formation places a significant burden on health care systems. Here Oddsson et al. perform a large-scale genome-wide association study and uncover new genetic variants associated with kidney stone susceptibility and associated biochemical traits.
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Affiliation(s)
| | | | - Hannes Helgason
- 1] deCODE genetics/Amgen, Inc., Reykjavik 101, Iceland [2] School of Engineering and Natural Sciences, University of Iceland, Reykjavik 101, Iceland
| | - Vidar O Edvardsson
- 1] Children's Medical Center, Landspitali-The National University Hospital of Iceland, Reykjavik 101, Iceland [2] Faculty of Medicine, University of Iceland, Reykjavik 101, Iceland [3] The Rare Kidney Stone Consortium, Mayo Clinic, Rochester, Minnesota, USA
| | | | | | | | - Gudmundur I Eyjolfsson
- Icelandic Medical Center (Laeknasetrid), Laboratory in Mjodd (RAM), Reykjavik 109, Iceland
| | - Olof Sigurdardottir
- Department of Clinical Biochemistry, Akureyri Hospital, Akureyri, 600, Iceland
| | - Isleifur Olafsson
- Department of Clinical Biochemistry, Landspitali University Hospital, Reykjavik 101, Iceland
| | - Gisli Masson
- deCODE genetics/Amgen, Inc., Reykjavik 101, Iceland
| | - Hilma Holm
- deCODE genetics/Amgen, Inc., Reykjavik 101, Iceland
| | - Daniel F Gudbjartsson
- 1] deCODE genetics/Amgen, Inc., Reykjavik 101, Iceland [2] School of Engineering and Natural Sciences, University of Iceland, Reykjavik 101, Iceland
| | - Unnur Thorsteinsdottir
- 1] deCODE genetics/Amgen, Inc., Reykjavik 101, Iceland [2] Faculty of Medicine, University of Iceland, Reykjavik 101, Iceland
| | - Olafur S Indridason
- Division of Nephrology, Internal Medicine Services, Landspitali-The National University Hospital of Iceland, Reykjavik Iceland
| | - Runolfur Palsson
- 1] Faculty of Medicine, University of Iceland, Reykjavik 101, Iceland [2] The Rare Kidney Stone Consortium, Mayo Clinic, Rochester, Minnesota, USA [3] Division of Nephrology, Internal Medicine Services, Landspitali-The National University Hospital of Iceland, Reykjavik Iceland
| | - Kari Stefansson
- 1] deCODE genetics/Amgen, Inc., Reykjavik 101, Iceland [2] Faculty of Medicine, University of Iceland, Reykjavik 101, Iceland
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25
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A Single Nucleotide Polymorphism (rs4236480) in TRPV5 Calcium Channel Gene Is Associated with Stone Multiplicity in Calcium Nephrolithiasis Patients. Mediators Inflamm 2015; 2015:375427. [PMID: 26089600 PMCID: PMC4452106 DOI: 10.1155/2015/375427] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 03/31/2015] [Accepted: 04/17/2015] [Indexed: 12/11/2022] Open
Abstract
Nephrolithiasis is characterized by calcification of stones in the kidneys from an unknown cause. Animal models demonstrated the functional roles of the transient receptor potential vanilloid member 5 (TRPV5) gene in calcium renal reabsorption and hypercalciuria. Therefore, TRPV5 was suggested to be involved in calcium homeostasis. However, whether genetic polymorphisms of TRPV5 are associated with kidney stone multiplicity or recurrence is unclear. In this study, 365 Taiwanese kidney-stone patients were recruited. Both biochemical data and DNA samples were collected. Genotyping was performed by a TaqMan allelic discrimination assay. We found that a TRPV5 polymorphism (rs4236480) was observed to be associated with stone multiplicity of calcium nephrolithiasis, as the risk of stone multiplicity was higher in patients with the TT+CT genotype than in patients with the CC genotype (p = 0.0271). In summary, despite the complexity of nephrolithiasis and the potential association of numerous calcium homeostatic absorption/reabsorption factors, TRPV5 plays an important role in the pathogenesis of calcium nephrolithiasis.
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26
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Ou SM, Chen YT, Shih CJ, Tarng DC. Increased risk of bone fracture among patients with urinary calculi: a nationwide longitudinal population-based study. Osteoporos Int 2015; 26:1261-9. [PMID: 25524022 DOI: 10.1007/s00198-014-2998-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 12/08/2014] [Indexed: 12/18/2022]
Abstract
UNLABELLED Urinary calculi were associated with higher risk of vertebral and upper limb fracture. Therefore, patients with urinary calculi should be evaluated carefully because they may have a higher risk of subsequent fracture later in life. INTRODUCTION The contribution of urinary calculi to reduced bone mineral density has been recognized. However, the association of urinary calculi with the risk of fracture remains inconclusive. The aim of the study was to determine the risk of overall fracture and fractures at different anatomic sites in patients with urinary calculi. METHODS The records of inpatients and outpatients with urinary calculi were retrieved from the Taiwan National Health Insurance Database from 2000 to 2010. Among patients with urinary calculi at the cohort entry, controls were matched using propensity scores on a 1:1 ratio. All subjects were followed up from the date of enrollment until fracture occurrence, death, or December 31, 2010. There were 46,243 Medicare beneficiaries with a diagnosis of urinary calculi and 46,243 controls without calculi enrolled. RESULTS Among these patients, 6005 patients with a diagnosis of urinary calculi and 5339 controls developed fractures during a median follow-up period of 5.3 years. Patients with urinary calculi had a higher incidence of fracture compared with controls (23.9 versus 22.1 per 1000 person-years) and a greater risk of overall fractures (adjusted hazard ratio [aHR] 1.08, 95 % confidence interval [CI], 1.04-1.12), mainly located at the vertebrae (aHR 1.15, 95 % CI, 1.06-1.25) and upper limb (aHR 1.07, 95 % CI, 1.01-1.14), but the risk for hip fracture was not increased (aHR 1.09, 95 % CI, 0.96-1.22). CONCLUSIONS Urinary calculus is independently associated with higher risk of subsequent fracture. Patients with urinary calculi should pay attention to the future vertebral and upper limb fractures.
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Affiliation(s)
- S-M Ou
- School of Medicine, National Yang-Ming University, No. 201, Section 2, Shih-Pai Road, Taipei, 11217, Taiwan
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27
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Mizuno H, Suzuki Y, Watanabe M, Sokabe T, Yamamoto T, Hattori R, Gotoh M, Tominaga M. Potential role of transient receptor potential (TRP) channels in bladder cancer cells. J Physiol Sci 2014; 64:305-14. [PMID: 24849279 PMCID: PMC10717035 DOI: 10.1007/s12576-014-0319-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Accepted: 05/01/2014] [Indexed: 12/15/2022]
Abstract
Transient receptor potential (TRP) channels play important roles in thermal, chemical, and mechanical sensation in various tissues. In this study, we investigated the differences in urothelial TRP channels between normal urothelial cells and bladder cancer cells. TRPV2 and TRPM7 expression levels and TRPV2 activator-induced intracellular Ca(2+) increases were significantly higher, whereas TRPV4 expression and TRPV4 activator-induced intracellular Ca(2+) increases were significantly lower in mouse bladder cancer (MBT-2) cells compared to normal mouse urothelial cells. The proliferation rate of MBT-2 cells overexpressing dominant-negative TRPV2 was significantly increased. In contrast, treatment with TRPV2 activators significantly decreased the proliferation rate. TRPM7-overexpressing MBT-2 cells proliferated more slowly, as compared to mock-transfected cells. Moreover, expression of dominant-negative TRPV2 significantly decreased plasma membrane Ca(2+) permeability of MBT-2 cells as compared to that in mock-transfected cells. Increases in the expression of TRPV2 mRNA, immunoreactivity, and TRPV2 activator-induced intracellular Ca(2+) were also observed in T24 human bladder cancer cells. These results suggested that TRPV2 and TRPM7 were functionally expressed in bladder cancer cells and served as negative regulators of bladder cancer cell proliferation, most likely to prevent excess mechanical stresses.
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Affiliation(s)
- Hideki Mizuno
- Division of Cell Signaling, Okazaki Institute for Integrative Bioscience (National Institute for Physiological Sciences), National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, 444-8787 Japan
- Department of Urology, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa, Nagoya, 466-8550 Japan
| | - Yoshiro Suzuki
- Division of Cell Signaling, Okazaki Institute for Integrative Bioscience (National Institute for Physiological Sciences), National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, 444-8787 Japan
- Department of Physiological Sciences, The Graduate University for Advanced Studies, 5-1, Higashiyama, Myodaiji, Okazaki, 444-8787 Japan
| | - Masaki Watanabe
- Division of Cell Signaling, Okazaki Institute for Integrative Bioscience (National Institute for Physiological Sciences), National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, 444-8787 Japan
| | - Takaaki Sokabe
- Division of Cell Signaling, Okazaki Institute for Integrative Bioscience (National Institute for Physiological Sciences), National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, 444-8787 Japan
| | - Tokunori Yamamoto
- Department of Urology, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa, Nagoya, 466-8550 Japan
| | - Ryohei Hattori
- Department of Urology, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa, Nagoya, 466-8550 Japan
| | - Momokazu Gotoh
- Department of Urology, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa, Nagoya, 466-8550 Japan
| | - Makoto Tominaga
- Division of Cell Signaling, Okazaki Institute for Integrative Bioscience (National Institute for Physiological Sciences), National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, 444-8787 Japan
- Department of Physiological Sciences, The Graduate University for Advanced Studies, 5-1, Higashiyama, Myodaiji, Okazaki, 444-8787 Japan
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28
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Abstract
TRPV5 is one of the two channels in the TRPV family that exhibit high selectivity to Ca(2+) ions. TRPV5 mediates Ca(2+) influx into cells as the first step to transport Ca(2+) across epithelia. The specialized distribution in the distal tubule of the kidney positions TRPV5 as a key player in Ca(2+) reabsorption. The responsiveness in expression and/or activity of TRPV5 to hormones such as 1,25-dihydroxyvitamin D3, parathyroid hormone, estrogen, and testosterone makes TRPV5 suitable for its role in the fine-tuning of Ca(2+) reabsorption. This role is further optimized by the modulation of TRPV5 trafficking and activity via its binding partners; co-expressed proteins; tubular factors such as calbindin-D28k, calmodulin, klotho, uromodulin, and plasmin; extracellular and intracellular factors such as proton, Mg(2+), Ca(2+), and phosphatidylinositol-4,5-bisphosphate; and fluid flow. These regulations allow TRPV5 to adjust its overall activity in response to the body's demand for Ca(2+) and to prevent kidney stone formation. A point mutation in mouse Trpv5 gene leads to hypercalciuria similar to Trpv5 knockout mice, suggesting a possible role of TRPV5 in hypercalciuric disorders in humans. In addition, the single nucleotide polymorphisms in Trpv5 gene prevalently present in African descents may contribute to the efficient renal Ca(2+) reabsorption among African descendants. TRPV5 represents a potential therapeutic target for disorders with altered Ca(2+) homeostasis.
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Affiliation(s)
- Tao Na
- Cell Collection and Research Center, Institute for Biological Product Control, National Institutes for Food and Drug Control, Beijing, China
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29
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Toka HR, Genovese G, Mount DB, Pollak MR, Curhan GC. Frequency of rare allelic variation in candidate genes among individuals with low and high urinary calcium excretion. PLoS One 2013; 8:e71885. [PMID: 23991001 PMCID: PMC3753300 DOI: 10.1371/journal.pone.0071885] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Accepted: 07/10/2013] [Indexed: 12/29/2022] Open
Abstract
Our study investigated the association of rare allelic variants with extremes of 24-hour urinary calcium excretion because higher urinary calcium excretion is a dominant risk factor for calcium-based kidney stone formation. We resequenced 40 candidate genes potentially related to urinary calcium excretion in individuals from the Nurses' Health Studies I & II and the Health Professionals Follow-up Study. A total of 960 participants were selected based on availability of 24-hour urine collection data and level of urinary calcium excretion (low vs. high). We utilized DNA sample pooling, droplet-based target gene enrichment, multiplexing, and high-throughput sequencing. Approximately 64% of samples (n = 615) showed both successful target enrichment and sequencing data with >20-fold deep coverage. A total of 259 novel allelic variants were identified. None of the rare gene variants (allele frequencies <2%) were found with increased frequency in the low vs. high urinary calcium groups; most of these variants were only observed in single individuals. Unadjusted analysis of variants with allele frequencies ≥ 2% suggested an association of the Claudin14 SNP rs113831133 with lower urinary calcium excretion (6/520 versus 29/710 haplotypes, P value = 0.003). Our data, together with previous human and animal studies, suggest a possible role for Claudin14 in urinary calcium excretion. Genetic validation studies in larger sample sets will be necessary to confirm our findings for rs113831133. In the tested set of candidate genes, rare allelic variants do not appear to contribute significantly to differences in urinary calcium excretion between individuals.
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Affiliation(s)
- Hakan R. Toka
- Division of Nephrology, Brigham and Women's Hospital, Boston, Massachusetts, United States of America
- Division of Nephrology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Giulio Genovese
- Division of Nephrology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - David B. Mount
- Division of Nephrology, Brigham and Women's Hospital, Boston, Massachusetts, United States of America
| | - Martin R. Pollak
- Division of Nephrology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Gary C. Curhan
- Division of Nephrology, Brigham and Women's Hospital, Boston, Massachusetts, United States of America
- Channing Division of Network Medicine, Boston, Massachusetts, United States of America
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