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Zhou Z, Gao P, Zhang T, Yang Y, Ding Q, Wu Z, Wang L. Functional analysis reveals calcium-sensing receptor gene regulating cell-cell junction in renal tubular epithelial cells. Int Urol Nephrol 2024; 56:2165-2177. [PMID: 38372840 DOI: 10.1007/s11255-024-03948-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 01/04/2024] [Indexed: 02/20/2024]
Abstract
PURPOSE Calcium-sensing receptor (CASR) influences the expression pattern of multiple genes in renal tubular epithelial cells. The objective of this inquiry was to explore the molecular mechanisms of CASR in renal tubular epithelial cells and nephrolithiasis. METHODS HK-2 cells were transfected with lentiviruses carrying either CASR (named CASR) or an empty vector negative control (named NC), as well as shRNA intended to target CASR (named shCASR) or its corresponding negative control (named shNC). CCK-8 assay was used to detect the effect of CASR on the proliferation of HK-2 cells. RNA-Sequencing was applied to explore potential pathways regulated by CASR in HK-2 cells. RESULTS PCR and western blot results showed that CASR expression was significantly increased in CASR cells and was decreased in shCASR cells when compared to their corresponding negative control, respectively. CCK-8 assay revealed that CASR inhibited the proliferation of HK-2 cells. RNA-Sequencing results suggested that the shCASR HK-2 cells exhibited a significant up-regulation of 345 genes and a down-regulation of 366 genes. These differentially expressed genes (DEGs) were related to cell apoptosis and cell development. In CASR HK-2 cells, 1103 DEGs primarily functioned in mitochondrial energy metabolism, and amino acid metabolism. With the Venn diagram, 4 DEGs (Clorf116, ENPP3, IL20RB, and CLDN2) were selected as the hub genes regulated by CASR. Enrichment analysis revealed that these hub genes were involved in cell-cell junction, and epithelial cell development. CONCLUSIONS In summary, our investigation has the potential to offer novel perspectives on CASR regulating cell-cell junction in HK-2 cells.
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Affiliation(s)
- Zijian Zhou
- Department of Urology, Huashan Hospital, Fudan University, Shanghai, 200040, People's Republic of China
- Clinical Research Center of Urolithiasis, Shanghai Medical College, Fudan University, Shanghai, 200040, People's Republic of China
| | - Peng Gao
- Department of Urology, Huashan Hospital, Fudan University, Shanghai, 200040, People's Republic of China
- Clinical Research Center of Urolithiasis, Shanghai Medical College, Fudan University, Shanghai, 200040, People's Republic of China
| | - Tongtong Zhang
- Urology Centre, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, 200040, People's Republic of China
| | - Yuanyuan Yang
- Department of Urology, Huashan Hospital, Fudan University, Shanghai, 200040, People's Republic of China
- Clinical Research Center of Urolithiasis, Shanghai Medical College, Fudan University, Shanghai, 200040, People's Republic of China
| | - Qiang Ding
- Department of Urology, Huashan Hospital, Fudan University, Shanghai, 200040, People's Republic of China
- Clinical Research Center of Urolithiasis, Shanghai Medical College, Fudan University, Shanghai, 200040, People's Republic of China
| | - Zhong Wu
- Department of Urology, Huashan Hospital, Fudan University, Shanghai, 200040, People's Republic of China.
- Clinical Research Center of Urolithiasis, Shanghai Medical College, Fudan University, Shanghai, 200040, People's Republic of China.
| | - Lujia Wang
- Department of Urology, Huashan Hospital, Fudan University, Shanghai, 200040, People's Republic of China.
- Clinical Research Center of Urolithiasis, Shanghai Medical College, Fudan University, Shanghai, 200040, People's Republic of China.
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2
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Florance JA, Schollum JBW, Pomeranc A, Endre ZH, Walker RJ. Autosomal dominant hypercalciuric hypocalcaemia: the calcium-sensing receptor in renal calcium homeostasis and the impact of renal transplantation. Intern Med J 2024; 54:852-860. [PMID: 38665051 DOI: 10.1111/imj.16403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Accepted: 03/28/2024] [Indexed: 06/18/2024]
Abstract
Calcium-sensing receptors (CaSRs) are G protein-coupled receptors that help maintain Ca2+ concentrations, modulating calciotropic hormone release (parathyroid hormone (PTH), calcitonin and 1,25-dihydroxyvitamin D) by direct actions in the kidneys, gastrointestinal tract and bone. Variability in population calcium levels has been attributed to single nucleotide polymorphisms in CaSR genes, and several conditions affecting calcium and phosphate homeostasis have been attributed to gain- or loss-of-function mutations. An example is autosomal dominant hypercalciuric hypocalcaemia, because of a missense mutation at codon 128 of chromosome 3, as reported in our specific case and her family. As a consequence of treating symptomatic hypocalcaemia as a child, this female subject slowly developed progressive end-stage kidney failure because of nephrocalcinosis and nephrolithiasis. After kidney transplantation, she remains asymptomatic, with decreased vitamin D and elemental calcium requirements, stable fluid and electrolyte homeostasis during intercurrent illnesses and has normalised urinary calcium and phosphate excretion, reducing the likelihood of hypercalciuria-induced graft impairment. We review the actions of the CaSR, its role in regulating renal Ca2+ homeostasis along with the impact of a proven gain-of-function mutation in the CaSR gene resulting in autosomal dominant hypercalciuric hypocalcaemia before and after kidney transplantation.
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Affiliation(s)
- James A Florance
- Department of Nephrology, Dunedin Hospital, Dunedin, Otago, New Zealand
| | - John B W Schollum
- Department of Nephrology, Dunedin Hospital, Dunedin, Otago, New Zealand
| | - Abigail Pomeranc
- Department of Nephrology, Dunedin Hospital, Dunedin, Otago, New Zealand
| | - Zoltan H Endre
- Department of Nephrology, Prince of Wales Clinical School, UNSW Medicine, Sydney, New South Wales, Australia
| | - Robert J Walker
- Department of Nephrology, Dunedin Hospital, Dunedin, Otago, New Zealand
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Küng CJ, Daryadel A, Fuente R, Haykir B, de Angelis MH, Hernando N, Rubio-Aliaga I, Wagner CA. A novel mouse model for familial hypocalciuric hypercalcemia (FHH1) reveals PTH-dependent and independent CaSR defects. Pflugers Arch 2024; 476:833-845. [PMID: 38386045 PMCID: PMC11033242 DOI: 10.1007/s00424-024-02927-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 02/11/2024] [Accepted: 02/12/2024] [Indexed: 02/23/2024]
Abstract
The Calcium-sensing receptor (CaSR) senses extracellular calcium, regulates parathyroid hormone (PTH) secretion, and has additional functions in various organs related to systemic and local calcium and mineral homeostasis. Familial hypocalciuric hypercalcemia type I (FHH1) is caused by heterozygous loss-of-function mutations in the CaSR gene, and is characterized by the combination of hypercalcemia, hypocalciuria, normal to elevated PTH, and facultatively hypermagnesemia and mild bone mineralization defects. To date, only heterozygous Casr null mice have been available as model for FHH1. Here we present a novel mouse FHH1 model identified in a large ENU-screen that carries an c.2579 T > A (p.Ile859Asn) variant in the Casr gene (CasrBCH002 mice). In order to dissect direct effects of the genetic variant from PTH-dependent effects, we crossed CasrBCH002 mice with PTH deficient mice. Heterozygous CasrBCH002 mice were fertile, had normal growth and body weight, were hypercalcemic and hypermagnesemic with inappropriately normal PTH levels and urinary calcium excretion replicating some features of FHH1. Hypercalcemia and hypermagnesemia were independent from PTH and correlated with higher expression of claudin 16 and 19 in kidneys. Likewise, reduced expression of the renal TRPM6 channel in CasrBCH002 mice was not dependent on PTH. In bone, mutations in Casr rescued the bone phenotype observed in Pth null mice by increasing osteoclast numbers and improving the columnar pattern of chondrocytes in the growth zone. In summary, CasrBCH002 mice represent a new model to study FHH1 and our results indicate that only a part of the phenotype is driven by PTH.
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Affiliation(s)
- Catharina J Küng
- Institute of Physiology, University of Zürich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
| | - Arezoo Daryadel
- Institute of Physiology, University of Zürich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
| | - Rocio Fuente
- Institute of Physiology, University of Zürich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
- Department of Morphology and Cellular Biology, University of Oviedo, Oviedo, Spain
| | - Betül Haykir
- Institute of Physiology, University of Zürich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
| | - Martin Hrabĕ de Angelis
- Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
- Lehrstuhl Für Experimentelle Genetik, Technische Universität München, Freising-Weihenstephan, Germany
- Member of German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Nati Hernando
- Institute of Physiology, University of Zürich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
| | - Isabel Rubio-Aliaga
- Institute of Physiology, University of Zürich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
| | - Carsten A Wagner
- Institute of Physiology, University of Zürich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland.
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Al-Shebel A, Michel G, Breiderhoff T, Müller D. Urinary Acidification Does Not Explain the Absence of Nephrocalcinosis in a Mouse Model of Familial Hypomagnesaemia with Hypercalciuria and Nephrocalcinosis (FHHNC). Int J Mol Sci 2024; 25:1779. [PMID: 38339056 PMCID: PMC10855382 DOI: 10.3390/ijms25031779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 01/25/2024] [Accepted: 01/28/2024] [Indexed: 02/12/2024] Open
Abstract
Patients with mutations in Cldn16 suffer from familial hypomagnesaemia with hypercalciuria and nephrocalcinosis (FHHNC) which can lead to renal insufficiency. Mice lacking claudin-16 show hypomagnesemia and hypercalciuria, but no nephrocalcinosis. Calcium oxalate and calcium phosphate are the most common insoluble calcium salts that accumulate in the kidney in the case of nephrocalcinosis, however, the formation of these salts is less favored in acidic conditions. Therefore, urine acidification has been suggested to limit the formation of calcium deposits in the kidney. Assuming that urine acidification is causative for the absence of nephrocalcinosis in the claudin-16-deficient mouse model, we aimed to alkalinize the urine of these mice by the ablation of the subunit B1 of the vesicular ATPase in addition to claudin-16. In spite of an increased urinary pH in mice lacking claudin-16 and the B1 subunit, nephrocalcinosis did not develop. Thus, urinary acidification is not the only factor preventing nephrocalcinosis in claudin-16 deficient mice.
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Affiliation(s)
- Amr Al-Shebel
- Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Pediatric Gastroenterology, Nephrology and Metabolic Diseases, Augustenburger Platz 1, 13353 Berlin, Germany; (T.B.); (D.M.)
| | - Geert Michel
- Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Research Institutes for Experimental Medicine, Transgenic Technologies, Robert Rössle Str. 10, 13125 Berlin, Germany;
| | - Tilman Breiderhoff
- Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Pediatric Gastroenterology, Nephrology and Metabolic Diseases, Augustenburger Platz 1, 13353 Berlin, Germany; (T.B.); (D.M.)
| | - Dominik Müller
- Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Pediatric Gastroenterology, Nephrology and Metabolic Diseases, Augustenburger Platz 1, 13353 Berlin, Germany; (T.B.); (D.M.)
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5
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Hakimi S, Dutta P, Layton AT. Coupling of renal sodium and calcium transport: a modeling analysis of transporter inhibition and sex differences. Am J Physiol Renal Physiol 2023; 325:F536-F551. [PMID: 37615047 DOI: 10.1152/ajprenal.00145.2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 08/17/2023] [Accepted: 08/17/2023] [Indexed: 08/25/2023] Open
Abstract
Ca2+ transport along the nephron occurs via specific transcellular and paracellular pathways and is coupled to the transport of other electrolytes. Notably, Na+ transport establishes an electrochemical gradient to drive Ca2+ reabsorption. Hence, alterations in renal Na+ handling, under pathophysiological conditions or pharmacological manipulations, can have major effects on Ca2+ transport. An important class of pharmacological agent is diuretics, which are commonly prescribed for the management of blood pressure and fluid balance. The pharmacological targets of diuretics generally directly facilitate Na+ transport but also indirectly affect renal Ca2+ handling. To better understand the underlying mechanisms, we developed a computational model of electrolyte transport along the superficial nephron in the kidney of a male and female rat. Sex differences in renal Ca2+ handling are represented. Model simulations predicted in the female rat nephron lower Ca2+ reabsorption in the proximal tubule and thick ascending limb, but higher reabsorption in the late distal convoluted tubule and connecting tubule, compared with the male nephron. The male rat kidney model yielded a higher urinary Ca2+ excretion than the female model, consistent with animal experiments. Model results indicated that along the proximal tubule and thick ascending limb, Ca2+ and Na+ transport occurred in parallel, but those processes were dissociated in the distal convoluted tubule. Additionally, we conducted simulations of inhibition of channels and transporters that play a major role in Na+ and Ca2+ transport. Simulation results revealed alterations in transepithelial Ca2+ transport, with differential effects among nephron segments and between the sexes.NEW & NOTEWORTHY The kidney plays an important role in the maintenance of whole body Ca2+ balance by regulating Ca2+ reabsorption and excretion. This computational modeling study provides insights into how Ca2+ transport along the nephron is coupled to Na+. Model results indicated that along the proximal tubule and thick ascending limb, Ca2+ and Na+ transport occur in parallel, but those processes were dissociated in the distal convoluted tubule. Simulations also revealed sex-specific responses to different pharmacological manipulations.
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Affiliation(s)
- Shervin Hakimi
- Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario, Canada
| | - Pritha Dutta
- Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario, Canada
| | - Anita T Layton
- Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario, Canada
- Department of Biology, Cheriton School of Computer Science, and School of Pharmacology, University of Waterloo, Waterloo, Ontario, Canada
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Gómez-Martín JM, Martínez-Vaello V. The importance of molecular diagnosis in the management of autosomal dominant hypocalcemia type 1 (ADH1): Case report. ANNALES D'ENDOCRINOLOGIE 2023; 84:88-89. [PMID: 36609127 DOI: 10.1016/j.ando.2022.12.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 11/30/2022] [Accepted: 12/01/2022] [Indexed: 12/23/2022]
Affiliation(s)
- Jesús M Gómez-Martín
- Department of Endocrinology and Nutrition, Hospital Universitario Ramón y Cajal, 28034 Madrid, Spain
| | - Victoria Martínez-Vaello
- Department of Endocrinology and Nutrition, Hospital Universitario Ramón y Cajal, 28034 Madrid, Spain.
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7
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Ali FT, El-Azeem EMA, Hekal HFA, El-Gizawy MM, Sayed MS, Mandoh AY, Soliman AF. Association of TRPV5, CASR, and CALCR genetic variants with kidney stone disease susceptibility in Egyptians through main effects and gene–gene interactions. Urolithiasis 2022; 50:701-710. [PMID: 36088585 PMCID: PMC9584976 DOI: 10.1007/s00240-022-01360-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 08/28/2022] [Indexed: 12/03/2022]
Abstract
Kidney stone disease (KSD) represents an urgent medical problem because of increasing its prevalence. Several functional polymorphisms in genes involved in the renal handling of calcium were associated with KSD pathogenesis. Among those, the rs4236480 of transient receptor potential vanilloid member 5 (TRPV5) gene, the rs1801725 of calcium-sensing receptor (CASR) gene, and the rs1801197 of calcitonin receptor (CALCR) gene appear to be of great importance. Due to the scarce data on the Egyptians, this study aimed to evaluate the association of these candidate genetic variants with the risk of developing KSD in an Egyptian population. To do so, the biochemical parameters were measured along with the genotyping of the three polymorphisms using allelic discrimination assay in 134 KSD patients and 86 age and sex-matched healthy subjects. The results showed that the genotypic distributions and allelic frequencies of the studied variants were significantly different between cases and controls. The three polymorphisms increased the risk of KSD significantly under all the tested genetic models (OR ranges from 2.152 to 5.994), except for the recessive model of the CALCR rs1801197 polymorphism after Bonferroni correction. The gene–gene interaction analyzed by multifactor dimensionality reduction selected the three-locus combination as the best model associated with the susceptibility to KSD with OR 9.706. Further, synergistic interactions were identified between TRPV5 rs4236480 and CALCR rs1801197 variants and CASR rs1801725 and CALCR rs1801197 variants. In conclusion, the TRPV5 rs4236480, CASR rs1801725, and CALCR rs1801197 polymorphisms showed a significant association with the risk of KSD in the Egyptian population. Furthermore, their complex interactions might have an impact on the genetic susceptibility to develop KSD.
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8
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AQP2 trafficking in health and diseases: an updated overview. Int J Biochem Cell Biol 2022; 149:106261. [DOI: 10.1016/j.biocel.2022.106261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 05/25/2022] [Accepted: 06/30/2022] [Indexed: 11/23/2022]
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Schepelmann M, Ranieri M, Lopez-Fernandez I, Webberley TS, Brennan SC, Yarova PL, Graca J, Hanif UK, Müller C, Manhardt T, Salzmann M, Quasnichka H, Price SA, Ward DT, Gilbert T, Matchkov VV, Fenton RA, Herberger A, Hwong J, Santa Maria C, Tu CL, Kallay E, Valenti G, Chang W, Riccardi D. Impaired Mineral Ion Metabolism in a Mouse Model of Targeted Calcium-Sensing Receptor (CaSR) Deletion from Vascular Smooth Muscle Cells. J Am Soc Nephrol 2022; 33:1323-1340. [PMID: 35581010 PMCID: PMC9257819 DOI: 10.1681/asn.2021040585] [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: 04/30/2021] [Accepted: 03/07/2022] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND Impaired mineral ion metabolism is a hallmark of CKD-metabolic bone disorder. It can lead to pathologic vascular calcification and is associated with an increased risk of cardiovascular mortality. Loss of calcium-sensing receptor (CaSR) expression in vascular smooth muscle cells exacerbates vascular calcification in vitro. Conversely, vascular calcification can be reduced by calcimimetics, which function as allosteric activators of CaSR. METHODS To determine the role of the CaSR in vascular calcification, we characterized mice with targeted Casr gene knockout in vascular smooth muscle cells ( SM22α CaSR Δflox/Δflox ). RESULTS Vascular smooth muscle cells cultured from the knockout (KO) mice calcified more readily than those from control (wild-type) mice in vitro. However, mice did not show ectopic calcifications in vivo but they did display a profound mineral ion imbalance. Specifically, KO mice exhibited hypercalcemia, hypercalciuria, hyperphosphaturia, and osteopenia, with elevated circulating fibroblast growth factor 23 (FGF23), calcitriol (1,25-D3), and parathyroid hormone levels. Renal tubular α-Klotho protein expression was increased in KO mice but vascular α-Klotho protein expression was not. Altered CaSR expression in the kidney or the parathyroid glands could not account for the observed phenotype of the KO mice. CONCLUSIONS These results suggest that, in addition to CaSR's established role in the parathyroid-kidney-bone axis, expression of CaSR in vascular smooth muscle cells directly contributes to total body mineral ion homeostasis.
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Affiliation(s)
- Martin Schepelmann
- School of Biosciences, Cardiff University, Cardiff, United Kingdom .,Institute of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria
| | - Marianna Ranieri
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | | | | | - Sarah C Brennan
- School of Biosciences, Cardiff University, Cardiff, United Kingdom.,Charles Perkins Centre, University of Sydney, Sydney, Australia
| | - Polina L Yarova
- School of Biosciences, Cardiff University, Cardiff, United Kingdom.,Translational and Clinical Research Institute, Newcastle University Medical School, Newcastle upon Tyne, United Kingdom
| | - Joao Graca
- School of Biosciences, Cardiff University, Cardiff, United Kingdom.,AstraZeneca, Macclesfield, United Kingdom
| | | | - Christian Müller
- Institute of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria
| | - Teresa Manhardt
- Institute of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria
| | - Martina Salzmann
- Institute of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria
| | - Helen Quasnichka
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | | | - Donald T Ward
- Division of Diabetes, Endocrinology, and Gastroenterology, University of Manchester, Manchester, United Kingdom
| | - Thierry Gilbert
- Centre for Developmental Biology, University Paul Sabatier, Toulouse, France
| | | | - Robert A Fenton
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Amanda Herberger
- Department of Medicine, University of California, San Francisco, California
| | - Jenna Hwong
- Department of Medicine, University of California, San Francisco, California
| | | | - Chia-Ling Tu
- Department of Medicine, University of California, San Francisco, California
| | - Enikö Kallay
- Institute of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria
| | - Giovanna Valenti
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Wenhan Chang
- Department of Medicine, University of California, San Francisco, California
| | - Daniela Riccardi
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
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10
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Lemoine S, Figueres L, Bacchetta J, Frey S, Dubourg L. Calcium homeostasis pathologies in hyperparathyroidism: nephrologic and endocrinologic points of view. ANNALES D'ENDOCRINOLOGIE 2022; 83:237-243. [DOI: 10.1016/j.ando.2022.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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11
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Huang JL, Mo ZY, Li ZY, Liang GY, Liu HL, Aschner M, Ou SY, Zhou B, Chen ZM, Jiang YM. Association of lead and cadmium exposure with kidney stone incidence: A study on the non-occupational population in Nandan of China. J Trace Elem Med Biol 2021; 68:126852. [PMID: 34508950 DOI: 10.1016/j.jtemb.2021.126852] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 08/16/2021] [Accepted: 08/24/2021] [Indexed: 11/30/2022]
Abstract
BACKGROUND Environmental lead (Pb) and cadmium (Cd) pollution has been considered a risk factor in the etiology of kidney stones. However, the association between Pb and Cd exposure and kidney stone incidence has yet to be determined. OBJECTIVES This study aimed to determine a possible the association between kidney stones with Pb and Cd exposure (alone or combined) in a non-occupational population. METHODS Pb and Cd contaminations in soil-plant system were determined by flame atomic absorption spectrophotometry. Health risk assessment of dietary Pb or Cd intake from rice and vegetables were calculated. Kidney stones were diagnosed with urinary tract ultrasonography. Urinary cadmium (UCd) and blood lead (BPb) levels were determined by graphite-furnace atomic absorption spectrometry. Multivariate logistic regression models were constructed. RESULTS The hazard indexes (HI) of Pb and Cd were 7.91 and 7.31. The odds ratio (OR) was 2.83 (95 %CI:1.38-5.77) in males with high BPb (BPb ≥ 100 μg/L), compared with those with low BPb (BPb<100 μg/L). Compared to those with low BPb and low UCd (BPb<100 μg/L and UCd<2 μg/g creatinine), the ORs were 2.58 (95 % CI:1.17-5.70) and 3.43 (95 % CI:1.21-9.16) in females and males with high BPb and high UCd (BPb ≥100 μg/L and UCd ≥2 μg/g creatinine), respectively. The OR was 3.16 (95 % CI:1.26-7.88) in males with high BPb and low UCd (BPb ≥ 100 μg/L and UCd <2 μg/g creatinine), compared to those with low BPb and low UCd. CONCLUSIONS Kidney stones incidence was increased by high Pb exposure in males, and by Pb and Cd co-exposure in males and females.
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Affiliation(s)
- Jiong-Li Huang
- Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning, 530021, China; Guangxi Colleges and Universities Key Laboratory of Prevention and Control of Highly Prevalent Diseases, Guangxi Medical University, Nanning, 530021, China; Atmospheric Environment Research Center, Scientific Research Academy of Guangxi Environmental Protection, Nanning, 530022, China
| | - Zhao-Yu Mo
- Atmospheric Environment Research Center, Scientific Research Academy of Guangxi Environmental Protection, Nanning, 530022, China; Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, China
| | - Zhong-You Li
- Department of Preventive Medicine, School of Public Health and Management, Guangxi University of Chinese Medicine, Nanning, 530200, China
| | - Gui-Yun Liang
- Atmospheric Environment Research Center, Scientific Research Academy of Guangxi Environmental Protection, Nanning, 530022, China
| | - Hui-Lin Liu
- Atmospheric Environment Research Center, Scientific Research Academy of Guangxi Environmental Protection, Nanning, 530022, China
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, 10461, United States
| | - Shi-Yan Ou
- Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning, 530021, China; Guangxi Colleges and Universities Key Laboratory of Prevention and Control of Highly Prevalent Diseases, Guangxi Medical University, Nanning, 530021, China
| | - Bin Zhou
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, China
| | - Zhi-Ming Chen
- Atmospheric Environment Research Center, Scientific Research Academy of Guangxi Environmental Protection, Nanning, 530022, China.
| | - Yue-Ming Jiang
- Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning, 530021, China; Guangxi Colleges and Universities Key Laboratory of Prevention and Control of Highly Prevalent Diseases, Guangxi Medical University, Nanning, 530021, China.
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12
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Tang PK, Geddes RF, Jepson RE, Elliott J. A feline-focused review of chronic kidney disease-mineral and bone disorders - Part 1: Physiology of calcium handling. Vet J 2021; 275:105719. [PMID: 34311095 DOI: 10.1016/j.tvjl.2021.105719] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 06/03/2021] [Accepted: 07/21/2021] [Indexed: 01/01/2023]
Abstract
Mineral derangements are a common consequence of chronic kidney disease (CKD). Despite the well-established role of phosphorus in the pathophysiology of CKD, the implications of calcium disturbances associated with CKD remain equivocal. Calcium plays an essential role in numerous physiological functions in the body and is a fundamental structural component of bone. An understanding of calcium metabolism is required to understand the potential adverse clinical implications and outcomes secondary to the (mal)adaptation of calcium-regulating hormones in CKD. The first part of this two-part review covers the physiology of calcium homeostasis (kidneys, intestines and bones) and details the intimate relationships between calcium-regulating hormones (parathyroid hormone, calcitriol, fibroblast growth factor 23, α-Klotho and calcitonin) and the role of the calcium-sensing receptor.
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Affiliation(s)
- Pak-Kan Tang
- Department of Comparative Biomedical Sciences, Royal Veterinary College, University of London, London, UK.
| | - Rebecca F Geddes
- Department of Clinical Science and Services, Royal Veterinary College, University of London, London, UK
| | - Rosanne E Jepson
- Department of Clinical Science and Services, Royal Veterinary College, University of London, London, UK
| | - Jonathan Elliott
- Department of Comparative Biomedical Sciences, Royal Veterinary College, University of London, London, UK
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Tan RSG, Lee CHL, Dimke H, Todd Alexander R. The role of calcium-sensing receptor signaling in regulating transepithelial calcium transport. Exp Biol Med (Maywood) 2021; 246:2407-2419. [PMID: 33926258 DOI: 10.1177/15353702211010415] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The calcium-sensing receptor (CaSR) plays a critical role in sensing extracellular calcium (Ca2+) and signaling to maintain Ca2+ homeostasis. In the parathyroid, the CaSR regulates secretion of parathyroid hormone, which functions to increase extracellular Ca2+ levels. The CaSR is also located in other organs imperative to Ca2+ homeostasis including the kidney and intestine, where it modulates Ca2+ reabsorption and absorption, respectively. In this review, we describe CaSR expression and its function in transepithelial Ca2+ transport in the kidney and intestine. Activation of the CaSR leads to G protein dependent and independent signaling cascades. The known CaSR signal transduction pathways involved in modulating paracellular and transcellular epithelial Ca2+ transport are discussed. Mutations in the CaSR cause a range of diseases that manifest in altered serum Ca2+ levels. Gain-of-function mutations in the CaSR result in autosomal dominant hypocalcemia type 1, while loss-of-function mutations cause familial hypocalciuric hypercalcemia. Additionally, the putative serine protease, FAM111A, is discussed as a potential regulator of the CaSR because mutations in FAM111A cause Kenny Caffey syndrome type 2, gracile bone dysplasia, and osteocraniostenosis, diseases that are characterized by hypocalcemia, hypoparathyroidism, and bony abnormalities, i.e. share phenotypic features of autosomal dominant hypocalcemia. Recent work has helped to elucidate the effect of CaSR signaling cascades on downstream proteins involved in Ca2+ transport across renal and intestinal epithelia; however, much remains to be discovered.
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Affiliation(s)
- Rebecca Siu Ga Tan
- Department of Physiology, University of Alberta, Edmonton T6G 1C9, Canada.,Membrane Protein Disease Research Group, University of Alberta, Edmonton T6G 1C9, Canada
| | | | - Henrik Dimke
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense 5000, Denmark.,Department of Nephrology, Odense University Hospital, Odense 5000, Denmark
| | - R Todd Alexander
- Department of Physiology, University of Alberta, Edmonton T6G 1C9, Canada.,Membrane Protein Disease Research Group, University of Alberta, Edmonton T6G 1C9, Canada.,Department of Pediatrics, University of Alberta, Edmonton T6G 1C9, Canada
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Hannan FM, Gorvin CM, Babinsky VN, Olesen MK, Stewart M, Wells S, Cox RD, Nemeth EF, Thakker RV. Calcilytic NPSP795 Increases Plasma Calcium and PTH in an Autosomal Dominant Hypocalcemia Type 1 Mouse Model. JBMR Plus 2020; 4:e10402. [PMID: 33103030 PMCID: PMC7574706 DOI: 10.1002/jbm4.10402] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 07/28/2020] [Indexed: 12/30/2022] Open
Abstract
Calcilytics are calcium‐sensing receptor (CaSR) antagonists that reduce the sensitivity of the CaSR to extracellular calcium. Calcilytics have the potential to treat autosomal dominant hypocalcemia type 1 (ADH1), which is caused by germline gain‐of‐function CaSR mutations and leads to symptomatic hypocalcemia, inappropriately low PTH concentrations, and hypercalciuria. To date, only one calcilytic compound, NPSP795, has been evaluated in patients with ADH1: Doses of up to 30 mg per patient have been shown to increase PTH concentrations, but did not significantly alter ionized blood calcium concentrations. The aim of this study was to further investigate NPSP795 for the treatment of ADH1 by undertaking in vitro and in vivo studies involving Nuf mice, which have hypocalcemia in association with a gain‐of‐function CaSR mutation, Leu723Gln. Treatment of HEK293 cells stably expressing the mutant Nuf (Gln723) CaSR with 20nM NPSP795 decreased extracellular Ca2+‐mediated intracellular calcium and phosphorylated ERK responses. An in vivo dose‐ranging study was undertaken by administering a s.c. bolus of NPSP795 at doses ranging from 0 to 30 mg/kg to heterozygous (Casr+/Nuf) and to homozygous (CasrNuf/Nuf) mice, and measuring plasma PTH responses at 30 min postdose. NPSP795 significantly increased plasma PTH concentrations in a dose‐dependent manner with the 30 mg/kg dose causing a maximal (≥10‐fold) rise in PTH. To determine whether NPSP795 can rectify the hypocalcemia of Casr+/Nuf and CasrNuf/Nuf mice, a submaximal dose (25 mg/kg) was administered, and plasma adjusted‐calcium concentrations measured over a 6‐hour period. NPSP795 significantly increased plasma adjusted‐calcium in Casr+/Nuf mice from 1.87 ± 0.03 mmol/L to 2.16 ± 0.06 mmol/L, and in CasrNuf/Nuf mice from 1.70 ± 0.03 mmol/L to 1.89 ± 0.05 mmol/L. Our findings show that NPSP795 elicits dose‐dependent increases in PTH and ameliorates the hypocalcemia in an ADH1 mouse model. Thus, calcilytics such as NPSP795 represent a potential targeted therapy for ADH1. © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.
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Affiliation(s)
- Fadil M Hannan
- Academic Endocrine Unit, Radcliffe Department of Medicine Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), University of Oxford Oxford UK
| | - Caroline M Gorvin
- Academic Endocrine Unit, Radcliffe Department of Medicine Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), University of Oxford Oxford UK
| | - Valerie N Babinsky
- Academic Endocrine Unit, Radcliffe Department of Medicine Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), University of Oxford Oxford UK
| | - Mie K Olesen
- Academic Endocrine Unit, Radcliffe Department of Medicine Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), University of Oxford Oxford UK
| | - Michelle Stewart
- MRC Mammalian Genetics Unit and Mary Lyon Centre MRC Harwell Institute, Harwell Science and Innovation Campus Oxford UK
| | - Sara Wells
- MRC Mammalian Genetics Unit and Mary Lyon Centre MRC Harwell Institute, Harwell Science and Innovation Campus Oxford UK
| | - Roger D Cox
- MRC Mammalian Genetics Unit and Mary Lyon Centre MRC Harwell Institute, Harwell Science and Innovation Campus Oxford UK
| | | | - Rajesh V Thakker
- Academic Endocrine Unit, Radcliffe Department of Medicine Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), University of Oxford Oxford UK
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Calcium-Sensing Receptor and Regulation of WNK Kinases in the Kidney. Cells 2020; 9:cells9071644. [PMID: 32659887 PMCID: PMC7407487 DOI: 10.3390/cells9071644] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 07/01/2020] [Accepted: 07/06/2020] [Indexed: 12/27/2022] Open
Abstract
The kidney is essential for systemic calcium homeostasis. Urinary calcium excretion can be viewed as an integrative renal response to endocrine and local stimuli. The extracellular calcium-sensing receptor (CaSR) elicits a number of adaptive reactions to increased plasma Ca2+ levels including the control of parathyroid hormone release and regulation of the renal calcium handling. Calcium reabsorption in the distal nephron of the kidney is functionally coupled to sodium transport. Apart from Ca2+ transport systems, CaSR signaling affects relevant distal Na+-(K+)-2Cl- cotransporters, NKCC2 and NCC. NKCC2 and NCC are activated by a kinase cascade comprising with-no-lysine [K] kinases (WNKs) and two homologous Ste20-related kinases, SPAK and OSR1. Gain-of-function mutations within the WNK-SPAK/OSR1-NKCC2/NCC pathway lead to renal salt retention and hypertension, whereas loss-of-function mutations have been associated with salt-losing tubulopathies such as Bartter or Gitelman syndromes. A Bartter-like syndrome has been also described in patients carrying gain-of-function mutations in the CaSR gene. Recent work suggested that CaSR signals via the WNK-SPAK/OSR1 cascade to modulate salt reabsorption along the distal nephron. The review presented here summarizes the latest progress in understanding of functional interactions between CaSR and WNKs and their potential impact on the renal salt handling and blood pressure.
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Leach K, Hannan FM, Josephs TM, Keller AN, Møller TC, Ward DT, Kallay E, Mason RS, Thakker RV, Riccardi D, Conigrave AD, Bräuner-Osborne H. International Union of Basic and Clinical Pharmacology. CVIII. Calcium-Sensing Receptor Nomenclature, Pharmacology, and Function. Pharmacol Rev 2020; 72:558-604. [PMID: 32467152 PMCID: PMC7116503 DOI: 10.1124/pr.119.018531] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The calcium-sensing receptor (CaSR) is a class C G protein-coupled receptor that responds to multiple endogenous agonists and allosteric modulators, including divalent and trivalent cations, L-amino acids, γ-glutamyl peptides, polyamines, polycationic peptides, and protons. The CaSR plays a critical role in extracellular calcium (Ca2+ o) homeostasis, as demonstrated by the many naturally occurring mutations in the CaSR or its signaling partners that cause Ca2+ o homeostasis disorders. However, CaSR tissue expression in mammals is broad and includes tissues unrelated to Ca2+ o homeostasis, in which it, for example, regulates the secretion of digestive hormones, airway constriction, cardiovascular effects, cellular differentiation, and proliferation. Thus, although the CaSR is targeted clinically by the positive allosteric modulators (PAMs) cinacalcet, evocalcet, and etelcalcetide in hyperparathyroidism, it is also a putative therapeutic target in diabetes, asthma, cardiovascular disease, and cancer. The CaSR is somewhat unique in possessing multiple ligand binding sites, including at least five putative sites for the "orthosteric" agonist Ca2+ o, an allosteric site for endogenous L-amino acids, two further allosteric sites for small molecules and the peptide PAM, etelcalcetide, and additional sites for other cations and anions. The CaSR is promiscuous in its G protein-coupling preferences, and signals via Gq/11, Gi/o, potentially G12/13, and even Gs in some cell types. Not surprisingly, the CaSR is subject to biased agonism, in which distinct ligands preferentially stimulate a subset of the CaSR's possible signaling responses, to the exclusion of others. The CaSR thus serves as a model receptor to study natural bias and allostery. SIGNIFICANCE STATEMENT: The calcium-sensing receptor (CaSR) is a complex G protein-coupled receptor that possesses multiple orthosteric and allosteric binding sites, is subject to biased signaling via several different G proteins, and has numerous (patho)physiological roles. Understanding the complexities of CaSR structure, function, and biology will aid future drug discovery efforts seeking to target this receptor for a diversity of diseases. This review summarizes what is known to date regarding key structural, pharmacological, and physiological features of the CaSR.
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Affiliation(s)
- Katie Leach
- Drug Discovery Biology, Monash Institute of Pharmaceutical Science, Monash University, Parkville, Australia (K.L., T.M.J., A.N.K.); Nuffield Department of Women's & Reproductive Health (F.M.H.) and Academic Endocrine Unit, Radcliffe Department of Clinical Medicine (F.M.H., R.V.T.), University of Oxford, Oxford, United Kingdom; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark (T.C.M., H.B.-O.); Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom (D.T.W.); Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria (E.K.); Physiology, School of Medical Sciences and Bosch Institute (R.S.M.) and School of Life & Environmental Sciences, Charles Perkins Centre (A.D.C.), University of Sydney, Sydney, Australia; and School of Biosciences, Cardiff University, Cardiff, United Kingdom (D.R.)
| | - Fadil M Hannan
- Drug Discovery Biology, Monash Institute of Pharmaceutical Science, Monash University, Parkville, Australia (K.L., T.M.J., A.N.K.); Nuffield Department of Women's & Reproductive Health (F.M.H.) and Academic Endocrine Unit, Radcliffe Department of Clinical Medicine (F.M.H., R.V.T.), University of Oxford, Oxford, United Kingdom; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark (T.C.M., H.B.-O.); Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom (D.T.W.); Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria (E.K.); Physiology, School of Medical Sciences and Bosch Institute (R.S.M.) and School of Life & Environmental Sciences, Charles Perkins Centre (A.D.C.), University of Sydney, Sydney, Australia; and School of Biosciences, Cardiff University, Cardiff, United Kingdom (D.R.)
| | - Tracy M Josephs
- Drug Discovery Biology, Monash Institute of Pharmaceutical Science, Monash University, Parkville, Australia (K.L., T.M.J., A.N.K.); Nuffield Department of Women's & Reproductive Health (F.M.H.) and Academic Endocrine Unit, Radcliffe Department of Clinical Medicine (F.M.H., R.V.T.), University of Oxford, Oxford, United Kingdom; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark (T.C.M., H.B.-O.); Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom (D.T.W.); Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria (E.K.); Physiology, School of Medical Sciences and Bosch Institute (R.S.M.) and School of Life & Environmental Sciences, Charles Perkins Centre (A.D.C.), University of Sydney, Sydney, Australia; and School of Biosciences, Cardiff University, Cardiff, United Kingdom (D.R.)
| | - Andrew N Keller
- Drug Discovery Biology, Monash Institute of Pharmaceutical Science, Monash University, Parkville, Australia (K.L., T.M.J., A.N.K.); Nuffield Department of Women's & Reproductive Health (F.M.H.) and Academic Endocrine Unit, Radcliffe Department of Clinical Medicine (F.M.H., R.V.T.), University of Oxford, Oxford, United Kingdom; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark (T.C.M., H.B.-O.); Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom (D.T.W.); Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria (E.K.); Physiology, School of Medical Sciences and Bosch Institute (R.S.M.) and School of Life & Environmental Sciences, Charles Perkins Centre (A.D.C.), University of Sydney, Sydney, Australia; and School of Biosciences, Cardiff University, Cardiff, United Kingdom (D.R.)
| | - Thor C Møller
- Drug Discovery Biology, Monash Institute of Pharmaceutical Science, Monash University, Parkville, Australia (K.L., T.M.J., A.N.K.); Nuffield Department of Women's & Reproductive Health (F.M.H.) and Academic Endocrine Unit, Radcliffe Department of Clinical Medicine (F.M.H., R.V.T.), University of Oxford, Oxford, United Kingdom; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark (T.C.M., H.B.-O.); Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom (D.T.W.); Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria (E.K.); Physiology, School of Medical Sciences and Bosch Institute (R.S.M.) and School of Life & Environmental Sciences, Charles Perkins Centre (A.D.C.), University of Sydney, Sydney, Australia; and School of Biosciences, Cardiff University, Cardiff, United Kingdom (D.R.)
| | - Donald T Ward
- Drug Discovery Biology, Monash Institute of Pharmaceutical Science, Monash University, Parkville, Australia (K.L., T.M.J., A.N.K.); Nuffield Department of Women's & Reproductive Health (F.M.H.) and Academic Endocrine Unit, Radcliffe Department of Clinical Medicine (F.M.H., R.V.T.), University of Oxford, Oxford, United Kingdom; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark (T.C.M., H.B.-O.); Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom (D.T.W.); Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria (E.K.); Physiology, School of Medical Sciences and Bosch Institute (R.S.M.) and School of Life & Environmental Sciences, Charles Perkins Centre (A.D.C.), University of Sydney, Sydney, Australia; and School of Biosciences, Cardiff University, Cardiff, United Kingdom (D.R.)
| | - Enikö Kallay
- Drug Discovery Biology, Monash Institute of Pharmaceutical Science, Monash University, Parkville, Australia (K.L., T.M.J., A.N.K.); Nuffield Department of Women's & Reproductive Health (F.M.H.) and Academic Endocrine Unit, Radcliffe Department of Clinical Medicine (F.M.H., R.V.T.), University of Oxford, Oxford, United Kingdom; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark (T.C.M., H.B.-O.); Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom (D.T.W.); Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria (E.K.); Physiology, School of Medical Sciences and Bosch Institute (R.S.M.) and School of Life & Environmental Sciences, Charles Perkins Centre (A.D.C.), University of Sydney, Sydney, Australia; and School of Biosciences, Cardiff University, Cardiff, United Kingdom (D.R.)
| | - Rebecca S Mason
- Drug Discovery Biology, Monash Institute of Pharmaceutical Science, Monash University, Parkville, Australia (K.L., T.M.J., A.N.K.); Nuffield Department of Women's & Reproductive Health (F.M.H.) and Academic Endocrine Unit, Radcliffe Department of Clinical Medicine (F.M.H., R.V.T.), University of Oxford, Oxford, United Kingdom; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark (T.C.M., H.B.-O.); Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom (D.T.W.); Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria (E.K.); Physiology, School of Medical Sciences and Bosch Institute (R.S.M.) and School of Life & Environmental Sciences, Charles Perkins Centre (A.D.C.), University of Sydney, Sydney, Australia; and School of Biosciences, Cardiff University, Cardiff, United Kingdom (D.R.)
| | - Rajesh V Thakker
- Drug Discovery Biology, Monash Institute of Pharmaceutical Science, Monash University, Parkville, Australia (K.L., T.M.J., A.N.K.); Nuffield Department of Women's & Reproductive Health (F.M.H.) and Academic Endocrine Unit, Radcliffe Department of Clinical Medicine (F.M.H., R.V.T.), University of Oxford, Oxford, United Kingdom; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark (T.C.M., H.B.-O.); Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom (D.T.W.); Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria (E.K.); Physiology, School of Medical Sciences and Bosch Institute (R.S.M.) and School of Life & Environmental Sciences, Charles Perkins Centre (A.D.C.), University of Sydney, Sydney, Australia; and School of Biosciences, Cardiff University, Cardiff, United Kingdom (D.R.)
| | - Daniela Riccardi
- Drug Discovery Biology, Monash Institute of Pharmaceutical Science, Monash University, Parkville, Australia (K.L., T.M.J., A.N.K.); Nuffield Department of Women's & Reproductive Health (F.M.H.) and Academic Endocrine Unit, Radcliffe Department of Clinical Medicine (F.M.H., R.V.T.), University of Oxford, Oxford, United Kingdom; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark (T.C.M., H.B.-O.); Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom (D.T.W.); Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria (E.K.); Physiology, School of Medical Sciences and Bosch Institute (R.S.M.) and School of Life & Environmental Sciences, Charles Perkins Centre (A.D.C.), University of Sydney, Sydney, Australia; and School of Biosciences, Cardiff University, Cardiff, United Kingdom (D.R.)
| | - Arthur D Conigrave
- Drug Discovery Biology, Monash Institute of Pharmaceutical Science, Monash University, Parkville, Australia (K.L., T.M.J., A.N.K.); Nuffield Department of Women's & Reproductive Health (F.M.H.) and Academic Endocrine Unit, Radcliffe Department of Clinical Medicine (F.M.H., R.V.T.), University of Oxford, Oxford, United Kingdom; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark (T.C.M., H.B.-O.); Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom (D.T.W.); Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria (E.K.); Physiology, School of Medical Sciences and Bosch Institute (R.S.M.) and School of Life & Environmental Sciences, Charles Perkins Centre (A.D.C.), University of Sydney, Sydney, Australia; and School of Biosciences, Cardiff University, Cardiff, United Kingdom (D.R.)
| | - Hans Bräuner-Osborne
- Drug Discovery Biology, Monash Institute of Pharmaceutical Science, Monash University, Parkville, Australia (K.L., T.M.J., A.N.K.); Nuffield Department of Women's & Reproductive Health (F.M.H.) and Academic Endocrine Unit, Radcliffe Department of Clinical Medicine (F.M.H., R.V.T.), University of Oxford, Oxford, United Kingdom; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark (T.C.M., H.B.-O.); Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom (D.T.W.); Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria (E.K.); Physiology, School of Medical Sciences and Bosch Institute (R.S.M.) and School of Life & Environmental Sciences, Charles Perkins Centre (A.D.C.), University of Sydney, Sydney, Australia; and School of Biosciences, Cardiff University, Cardiff, United Kingdom (D.R.)
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Imenez Silva PH, Katamesh-Benabbas C, Chan K, Pastor Arroyo EM, Knöpfel T, Bettoni C, Ludwig MG, Gasser JA, Brandao-Burch A, Arnett TR, Bonny O, Seuwen K, Wagner CA. The proton-activated ovarian cancer G protein-coupled receptor 1 (OGR1) is responsible for renal calcium loss during acidosis. Kidney Int 2020; 97:920-933. [DOI: 10.1016/j.kint.2019.12.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 11/29/2019] [Accepted: 12/05/2019] [Indexed: 12/19/2022]
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Abstract
Acid-base balance is critical for normal life. Acute and chronic disturbances impact cellular energy metabolism, endocrine signaling, ion channel activity, neuronal activity, and cardiovascular functions such as cardiac contractility and vascular blood flow. Maintenance and adaptation of acid-base homeostasis are mostly controlled by respiration and kidney. The kidney contributes to acid-base balance by reabsorbing filtered bicarbonate, regenerating bicarbonate through ammoniagenesis and generation of protons, and by excreting acid. This review focuses on acid-base disorders caused by renal processes, both inherited and acquired. Distinct rare inherited monogenic diseases affecting acid-base handling in the proximal tubule and collecting duct have been identified. In the proximal tubule, mutations of solute carrier 4A4 (SLC4A4) (electrogenic Na+/HCO3--cotransporter Na+/bicarbonate cotransporter e1 [NBCe1]) and other genes such as CLCN5 (Cl-/H+-antiporter), SLC2A2 (GLUT2 glucose transporter), or EHHADH (enoyl-CoA, hydratase/3-hydroxyacyl CoA dehydrogenase) causing more generalized proximal tubule dysfunction can cause proximal renal tubular acidosis resulting from bicarbonate wasting and reduced ammoniagenesis. Mutations in adenosine triphosphate ATP6V1 (B1 H+-ATPase subunit), ATPV0A4 (a4 H+-ATPase subunit), SLC4A1 (anion exchanger 1), and FOXI1 (forkhead transcription factor) cause distal renal tubular acidosis type I. Carbonic anhydrase II mutations affect several nephron segments and give rise to a mixed proximal and distal phenotype. Finally, mutations in genes affecting aldosterone synthesis, signaling, or downstream targets can lead to hyperkalemic variants of renal tubular acidosis (type IV). More common forms of renal acidosis are found in patients with advanced stages of chronic kidney disease and are owing, at least in part, to a reduced capacity for ammoniagenesis.
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Affiliation(s)
- Carsten A Wagner
- Institute of Physiology, University of Zurich, Zurich, Switzerland; National Center for Competence in Research Kidney, Switzerland.
| | - Pedro H Imenez Silva
- Institute of Physiology, University of Zurich, Zurich, Switzerland; National Center for Competence in Research Kidney, Switzerland
| | - Soline Bourgeois
- Institute of Physiology, University of Zurich, Zurich, Switzerland; National Center for Competence in Research Kidney, Switzerland
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Chen WC, Chou WH, Chu HW, Huang CC, Liu X, Chang WP, Chou YH, Chang WC. The rs1256328 (ALPL) and rs12654812 (RGS14) Polymorphisms are Associated with Susceptibility to Calcium Nephrolithiasis in a Taiwanese population. Sci Rep 2019; 9:17296. [PMID: 31754202 PMCID: PMC6872875 DOI: 10.1038/s41598-019-53261-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Accepted: 09/17/2019] [Indexed: 12/19/2022] Open
Abstract
Nephrolithiasis is a common disease affecting almost all populations, with an increasing prevalence over the past decades. Previous studies revealed several functional polymorphisms associated with the pathogenesis of nephrolithiasis. However, data on Asian populations are limited. In this study, three candidate polymorphisms were selected from previous studies to investigate the correlations with nephrolithiasis in a Taiwanese population. In total, 454 nephrolithiasis patients were recruited from Kaohsiung Medical University Hospital, with SNP frequency for 1513 subjects of general population from the Taiwan Biobank (TWB) as a genotypic reference. Results revealed that subjects with minor TT genotype at rs1256328 (alkaline phosphatase, liver/bone/kidney (ALPL)) have higher susceptibility to nephrolithiasis (odds ratio (OR) = 2.03, p = 0.0013). In addition, subjects carrying the minor AA genotype at rs12654812 (regulator of G protein signaling 14 (RGS14)) have higher susceptibility to nephrolithiasis (OR = 1.91, p = 0.0017). Among nephrolithiasis patients, subjects with GG at rs7627468 (calcium-sensing receptor (CASR)) have lower pH level in urine (p = 0.0088). Importantly, rs7627468 is associated with the expressions of IQCB1 and EAF2. rs12654812 could influence the expression of RGS14 itself, MXD3, and FGFR4. In summary, this study successfully validated the genetic roles of rs1256328 and rs12654812 in human nephrolithiasis.
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Affiliation(s)
- Wei-Chiao Chen
- Institute of Clinical Pharmacy and Pharmaceutical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Department of Urology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
- Department of Clinical Pharmacy, School of Pharmacy, Taipei Medical University, Taipei, Taiwan
| | - Wan-Hsuan Chou
- Department of Clinical Pharmacy, School of Pharmacy, Taipei Medical University, Taipei, Taiwan
| | - Hou-Wei Chu
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Chi-Chen Huang
- Graduate Institute of Neural Regenerative Medicine, College of Medical Science and Technology/Center for Neurotrauma and Neuroregeneration, Taipei Medical University, Taipei, Taiwan
| | - Xiao Liu
- Department of Human Genetics, The University of Chicago, Chicago, USA
| | - Wei-Pin Chang
- School of Health Care Administration, College of Management, Taipei Medical University, Taipei, Taiwan.
| | - Yii-Her Chou
- Department of Urology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.
| | - Wei-Chiao Chang
- Department of Clinical Pharmacy, School of Pharmacy, Taipei Medical University, Taipei, Taiwan.
- Master Program for Clinical Pharmacogenomics and Pharmacoproteomics, School of Pharmacy, Taipei Medical University, Taipei, Taiwan.
- Integrative Research Center for Critical Care, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan.
- Department of Medical Research, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan.
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20
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Renal Ca 2+ and Water Handling in Response to Calcium Sensing Receptor Signaling: Physiopathological Aspects and Role of CaSR-Regulated microRNAs. Int J Mol Sci 2019; 20:ijms20215341. [PMID: 31717830 PMCID: PMC6862519 DOI: 10.3390/ijms20215341] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 10/17/2019] [Accepted: 10/23/2019] [Indexed: 12/31/2022] Open
Abstract
Calcium (Ca2+) is a universal and vital intracellular messenger involved in a diverse range of cellular and biological processes. Changes in the concentration of extracellular Ca2+ can disrupt the normal cellular activities and the physiological function of these systems. The calcium sensing receptor (CaSR) is a unique G protein-coupled receptor (GPCR) activated by extracellular Ca2+ and by other physiological cations, aminoacids, and polyamines. CaSR is the main controller of the extracellular Ca2+ homeostatic system by regulating parathyroid hormone (PTH) secretion and, in turn, Ca2+ absorption and resorption. Recent advances highlight novel signaling pathways activated by CaSR signaling involving the regulation of microRNAs (miRNAs). miRNAs are naturally-occurring small non-coding RNAs that regulate post-transcriptional gene expression and are involved in several diseases. We previously described that high luminal Ca2+ in the renal collecting duct attenuates short-term vasopressin-induced aquaporin-2 (AQP2) trafficking through CaSR activation. Moreover, we demonstrated that CaSR signaling reduces AQP2 abundance via AQP2-targeting miRNA-137. This review summarizes the recent data related to CaSR-regulated miRNAs signaling pathways in the kidney.
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van der Wijst J, van Goor MK, Schreuder MF, Hoenderop JG. TRPV5 in renal tubular calcium handling and its potential relevance for nephrolithiasis. Kidney Int 2019; 96:1283-1291. [PMID: 31471161 DOI: 10.1016/j.kint.2019.05.029] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 05/21/2019] [Accepted: 05/22/2019] [Indexed: 10/26/2022]
Abstract
Nephrolithiasis or renal stone disease is an increasingly common problem, and its relatively high recurrence rate demands better treatment options. The majority of patients with nephrolithiasis have stones that contain calcium (Ca2+), which develop upon "supersaturation" of the urine with insoluble Ca2+ salts; hence processes that influence the delivery and renal handling of Ca2+ may influence stone formation. Idiopathic hypercalciuria is indeed frequently observed in patients with kidney stones that contain Ca2+. Genetic screens of nephrolithiasis determinants have identified an increasing number of gene candidates, most of which are involved in renal Ca2+ handling. This review provides an outline of the current knowledge regarding genetics of nephrolithiasis and will mainly focus on the epithelial Ca2+ channel transient receptor potential vanilloid 5 (TRPV5), an important player in Ca2+ homeostasis. Being a member of the TRP family of ion channels, TRPV5 is currently part of a revolution in structural biology. Recent technological breakthroughs in the cryo-electron microscopy field, combined with improvements in biochemical sample preparation, have resulted in high-resolution 3-dimensional structural models of integral membrane proteins, including TRPV5. These models currently are being used to explore the proteins' structure-function relationship, elucidate the molecular mechanisms of channel regulation, and study the putative effects of disease variants. Combined with other multidisciplinary approaches, this approach may open an avenue toward better understanding of the pathophysiological mechanisms involved in hypercalciuria and stone formation, and ultimately it may facilitate prevention of stone recurrence through the development of effective drugs.
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Affiliation(s)
- Jenny van der Wijst
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, the Netherlands
| | - Mark K van Goor
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, the Netherlands
| | - Michiel F Schreuder
- Department of Pediatric Nephrology, Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, the Netherlands
| | - Joost G Hoenderop
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, the Netherlands.
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22
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Wu M, Wang SS, Cao JY, Tang TT, Gao M, Ma KL, Liu BC. Calcium-sensing receptor mediates interleukin-1β-induced collagen expression in mouse collecting duct cells. J Cell Biochem 2019; 120:7353-7362. [PMID: 30525213 DOI: 10.1002/jcb.28010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 10/10/2018] [Indexed: 01/24/2023]
Abstract
The mechanisms that underlie the profibrotic effect of interleukin (IL)-1β are complicated and not fully understood. Recent evidence has suggested the involvement of the calcium-sensing receptor (CaSR) in tubular injury. Therefore, the current study aimed to investigate whether CaSR mediates IL-1β-induced collagen expression in cultured mouse inner medullary collecting duct cells (mIMCD3) and to determine the possible downstream signaling effector. The results showed that IL-1β significantly upregulated the expression of type I and III collagens in a concentration- and time-dependent manner. Moreover, CaSR was expressed in mIMCD3 cells, and its expression was increased by increasing the concentrations and times of IL-1β treatment. Selective inhibitors (Calhex231 or NPS2143) or the siRNA of CaSR attenuated the enhanced expression of type I and III collagens. Furthermore, IL-1β increased nuclear β-catenin protein levels and decreased cytoplasmic β-catenin expression in cells. In contrast, blockage of CaSR by the pharmacological antagonists or siRNA could partially attenuate such changes in the IL-1β-induced nuclear translocation of β-catenin. DKK1, an inhibitor of β-catenin nuclear translocation, further inhibited the expression of type I and III collagens in cells treated with IL-1β plus CaSR antagonist. In summary, these data demonstrated that IL-1β-induced collagen I and III expressions in collecting duct cells might be partially mediated by CaSR and the downstream nuclear translocation of β-catenin.
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Affiliation(s)
- Min Wu
- Department of Nephrology, Zhongda Hospital, Institute of Nephrology, Southeast University School of Medicine, Nanjing, China
| | - Si-Si Wang
- Department of Nephrology, Zhongda Hospital, Institute of Nephrology, Southeast University School of Medicine, Nanjing, China
| | - Jing-Yuan Cao
- Department of Nephrology, Zhongda Hospital, Institute of Nephrology, Southeast University School of Medicine, Nanjing, China
| | - Tao-Tao Tang
- Department of Nephrology, Zhongda Hospital, Institute of Nephrology, Southeast University School of Medicine, Nanjing, China
| | - Min Gao
- Department of Nephrology, Zhongda Hospital, Institute of Nephrology, Southeast University School of Medicine, Nanjing, China
| | - Kun-Ling Ma
- Department of Nephrology, Zhongda Hospital, Institute of Nephrology, Southeast University School of Medicine, Nanjing, China
| | - Bi-Cheng Liu
- Department of Nephrology, Zhongda Hospital, Institute of Nephrology, Southeast University School of Medicine, Nanjing, China
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23
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Wu M, Feng Y, Ye GX, Han YC, Wang SS, Ni HF, Wang FM, Gao M, Lv LL, Liu BC. Calcium-sensing receptor activation attenuates collagen expression in renal proximal tubular epithelial cells. Am J Physiol Renal Physiol 2019; 316:F1006-F1015. [PMID: 30838870 DOI: 10.1152/ajprenal.00413.2018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
316: F1006-F1015, 2019. First published March 6, 2019; doi: 10.1152/ajprenal.00413.2018 .-Experimental studies have shown that pharmacological activation of calcium-sensing receptor (CaSR) attenuates renal fibrosis in some animal models beyond modification of bone and mineral homeostasis; however, its underlying mechanisms remain largely unknown. Since excessive collagen deposition is the key feature of fibrosis, the present study aimed to examine whether CaSR was involved in the regulation of collagen expression in rats with adenine diet-induced renal fibrosis and in profibrotic transforming growth factor (TGF)-β1-treated renal proximal tubular epithelial cells (PTECs). The results showed that the CaSR agonist cinacalcet significantly attenuated renal collagen accumulation and tubular injury in adenine diet-fed rats. Additionally, the in vitro experiment showed that profibrotic TGF-β1 significantly increased the expression of collagen and decreased CaSR expression at the mRNA and protein levels in a concentration- and time-dependent manner. Furthermore, the CaSR CRISPR activation plasmid and cinacalcet partially abrogated the upregulation of collagen induced by TGF-β1 treatment. Blockade of CaSR by the CRISPR/Cas9 KO plasmid or the pharmacological antagonist Calhex231 further enhanced TGF-β1-induced collagen expression. Mechanistic experiments found that Smad2 phosphorylation and Snail expression were markedly increased in PTECs treated with TGF-β1, whereas the CaSR CRISPR activation plasmid and cinacalcet substantially suppressed this induction. In summary, this study provides evidence for a direct renal tubular epithelial protective effect of CaSR activation in renal fibrosis, possibly through suppression of collagen expression in PTECs.
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Affiliation(s)
- Min Wu
- Institute of Nephrology, Zhongda Hospital, Southeast University School of Medicine , Nanjing , China
| | - Ye Feng
- Institute of Nephrology, Zhongda Hospital, Southeast University School of Medicine , Nanjing , China
| | - Guo-Xin Ye
- Institute of Nephrology, Zhongda Hospital, Southeast University School of Medicine , Nanjing , China
| | - Yu-Chen Han
- Institute of Nephrology, Zhongda Hospital, Southeast University School of Medicine , Nanjing , China
| | - Si-Si Wang
- Institute of Nephrology, Zhongda Hospital, Southeast University School of Medicine , Nanjing , China
| | - Hai-Feng Ni
- Institute of Nephrology, Zhongda Hospital, Southeast University School of Medicine , Nanjing , China
| | - Feng-Mei Wang
- Institute of Nephrology, Zhongda Hospital, Southeast University School of Medicine , Nanjing , China
| | - Min Gao
- Institute of Nephrology, Zhongda Hospital, Southeast University School of Medicine , Nanjing , China
| | - Lin-Li Lv
- Institute of Nephrology, Zhongda Hospital, Southeast University School of Medicine , Nanjing , China
| | - Bi-Cheng Liu
- Institute of Nephrology, Zhongda Hospital, Southeast University School of Medicine , Nanjing , China
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24
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Wang B, Wang-France J, Li H, Sansom SC. Furosemide reduces BK-αβ4-mediated K + secretion in mice on an alkaline high-K + diet. Am J Physiol Renal Physiol 2019; 316:F341-F350. [PMID: 30484346 DOI: 10.1152/ajprenal.00223.2018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Special high-K diets have cardioprotective effects and are often warranted in conjunction with diuretics such as furosemide for treating hypertension. However, it is not understood how a high-K diet (HK) influences the actions of diuretics on renal K+ handling. Furosemide acidifies the urine by increasing acid secretion via the Na+-H+ exchanger 3 (NHE3) in TAL and vacuolar H+-ATPase (V-ATPase) in the distal nephron. We previously found that an alkaline urine is required for large conductance Ca2+-activated K+ (BK)-αβ4-mediated K+ secretion in mice on HK. We therefore hypothesized that furosemide could reduce BK-αβ4-mediated K+ secretion by acidifying the urine. Treating with furosemide (drinking water) for 11 days led to decreased urine pH in both wild-type (WT) and BK-β4-knockout mice (BK-β4-KO) with increased V-ATPase expression and elevated plasma aldosterone levels. However, furosemide decreased renal K+ clearance and elevated plasma [K+] in WT but not BK-β4-KO. Western blotting and immunofluorescence staining showed that furosemide treatment decreased cortical expression of BK-β4 and reduced apical localization of BK-α in connecting tubules. Addition of the carbonic anhydrase inhibitor, acetazolamide, to furosemide water restored urine pH along with renal K+ clearance and plasma [K+] to control levels. Acetazolamide plus furosemide also restored the cortical expression of BK-β4 and BK-α in connecting tubules. These results indicate that in mice adapted to HK, furosemide reduces BK-αβ4-mediated K+ secretion by acidifying the urine.
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Affiliation(s)
- Bangchen Wang
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center , Omaha, Nebraska
| | - Jun Wang-France
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center , Omaha, Nebraska
| | - Huaqing Li
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center , Omaha, Nebraska
| | - Steven C Sansom
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center , Omaha, Nebraska
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Affiliation(s)
- Mauricio Carvalho
- Universidade Federal do Paraná, Departamento de Clínica Médica, Hospital de Clínicas, Curitiba, PR, Brasil.,Pontifícia Universidade Católica do Paraná, Escola de Medicina, Curitiba, PR, Brasil
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26
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Hannan FM, Kallay E, Chang W, Brandi ML, Thakker RV. The calcium-sensing receptor in physiology and in calcitropic and noncalcitropic diseases. Nat Rev Endocrinol 2018; 15:33-51. [PMID: 30443043 PMCID: PMC6535143 DOI: 10.1038/s41574-018-0115-0] [Citation(s) in RCA: 189] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The Ca2+-sensing receptor (CaSR) is a dimeric family C G protein-coupled receptor that is expressed in calcitropic tissues such as the parathyroid glands and the kidneys and signals via G proteins and β-arrestin. The CaSR has a pivotal role in bone and mineral metabolism, as it regulates parathyroid hormone secretion, urinary Ca2+ excretion, skeletal development and lactation. The importance of the CaSR for these calcitropic processes is highlighted by loss-of-function and gain-of-function CaSR mutations that cause familial hypocalciuric hypercalcaemia and autosomal dominant hypocalcaemia, respectively, and also by the fact that alterations in parathyroid CaSR expression contribute to the pathogenesis of primary and secondary hyperparathyroidism. Moreover, the CaSR is an established therapeutic target for hyperparathyroid disorders. The CaSR is also expressed in organs not involved in Ca2+ homeostasis: it has noncalcitropic roles in lung and neuronal development, vascular tone, gastrointestinal nutrient sensing, wound healing and secretion of insulin and enteroendocrine hormones. Furthermore, the abnormal expression or function of the CaSR is implicated in cardiovascular and neurological diseases, as well as in asthma, and the CaSR is reported to protect against colorectal cancer and neuroblastoma but increase the malignant potential of prostate and breast cancers.
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Affiliation(s)
- Fadil M Hannan
- Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, UK
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Enikö Kallay
- Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria
| | - Wenhan Chang
- Endocrine Research Unit, Veterans Affairs Medical Center, University of California, San Francisco, San Francisco, CA, USA
| | - Maria Luisa Brandi
- Metabolic Bone Diseases Unit, Department of Surgery and Translational Medicine, University of Florence, Florence, Italy.
| | - Rajesh V Thakker
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.
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27
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Calcium-sensing receptor: evidence and hypothesis for its role in nephrolithiasis. Urolithiasis 2018; 47:23-33. [PMID: 30446806 DOI: 10.1007/s00240-018-1096-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 11/08/2018] [Indexed: 12/22/2022]
Abstract
Calcium-sensing receptor (CaSR) is a plasma-membrane G protein-coupled receptor activated by extracellular calcium and expressed in kidney tubular cells. It inhibits calcium reabsorption in the ascending limb and distal convoluted tubule when stimulated by the increase of serum calcium levels; therefore, these tubular segments are enabled by CaSR to play a substantial role in the regulation of serum calcium levels. In addition, CaSR increases water and proton excretion in the collecting duct and promotes phosphate reabsorption and citrate excretion in the proximal tubule. These CaSR activities form a network in which they are integrated to protect the kidney against the negative effects of high calcium concentrations and calcium precipitates in urine. Therefore, the CaSR gene has been considered as a candidate to explain calcium nephrolithiasis. Epidemiological studies observed that calcium nephrolithiasis was associated with polymorphisms of the CaSR gene regulatory region, rs6776158, located within the promoter-1, rs1501899 located in the intron 1, and rs7652589 in the 5'-untranslated region. These polymorphisms were found to reduce the transcriptional activity of promoter-1. Activating rs1042636 polymorphism located in exon 7 was associated with calcium nephrolithiasis and hypercalciuria. Genetic polymorphisms decreasing CaSR expression could predispose individuals to stones because they may impair CaSR protective effects against precipitation of calcium phosphate and oxalate. Activating polymorphisms rs1042636 could predispose to calcium stones by increasing calcium excretion. These findings suggest that CaSR may play a complex role in lithogenesis through different pathways having different relevance under different clinical conditions.
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28
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Affiliation(s)
- Alan M Weinstein
- Department of Physiology and Biophysics Department of Medicine, Weill Medical College of Cornell University , New York, New York
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29
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Dos Santos PMC, Amaral D, Tararthuch AL, Fernandez R. Calcium-sensing receptor (CaSR) modulates vacuolar H +-ATPase activity in a cell model of proximal tubule. Clin Exp Nephrol 2018; 22:1258-1265. [PMID: 29961155 DOI: 10.1007/s10157-018-1613-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 06/18/2018] [Indexed: 10/28/2022]
Abstract
BACKGROUND The calcium-sensing receptor (CaSR) is localized in the apical membrane of proximal tubules in close proximity to the transporters responsible for proton secretion. Therefore, the aim of the present study was to analyze the effects of CaSR stimulation on the biochemical activity of the vacuolar H+-ATPase in a cellular model of proximal tubule cells, OKP cells. METHODS Biochemical activity of H+-ATPase was performed using cell homogenates, and the inorganic phosphate released was determined by a colorimetric method. Changes in cytosolic ionized calcium [Ca2+]i were also determined using Fluo-4. RESULTS A significant increase of vacuolar H+-ATPase activity was observed when the CaSR was stimulated with agonists such as Gd3+ (300 µM) and neomycin (200 µM). This activity was also stimulated in a dose-dependent fashion by changes in extracellular Ca2+ (Ca2+o) between 10-4 and 2 mM. Gd3+ and neomycin produced a sustained rise of [Ca2+]i, an effect that disappears when extracellular calcium was removed in the presence of 0.1 µM thapsigargin. Inhibition of phospholipase C (PLC) activity with U73122 (5 × 10-8 M) reduced the increase in [Ca2+]i induced by neomycin. CONCLUSION CaSR stimulation induces an increase in the vacuolar H+-ATPase activity of OKP cells, an effect that involves an increase in [Ca2+]i and require phospholipase C activity. The consequent decrease in intratubular pH could lead to increase ionization of luminal calcium, potentially enhancing its reabsorption in distal tubule segments and reducing the formation of calcium phosphate stones.
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Affiliation(s)
- Priscilla Marys Costa Dos Santos
- Departamento de Fisiologia, Setor de Ciências Biológicas, UFPR, Centro Politécnico s/n., Jd. das Américas, Postal Box: 19031, Curitiba, PR, 81531-990, Brazil
| | - Deividi Amaral
- Departamento de Fisiologia, Setor de Ciências Biológicas, UFPR, Centro Politécnico s/n., Jd. das Américas, Postal Box: 19031, Curitiba, PR, 81531-990, Brazil
| | - Ana Lucia Tararthuch
- Departamento de Fisiologia, Setor de Ciências Biológicas, UFPR, Centro Politécnico s/n., Jd. das Américas, Postal Box: 19031, Curitiba, PR, 81531-990, Brazil
| | - Ricardo Fernandez
- Departamento de Fisiologia, Setor de Ciências Biológicas, UFPR, Centro Politécnico s/n., Jd. das Américas, Postal Box: 19031, Curitiba, PR, 81531-990, Brazil.
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30
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Abstract
Distal renal tubular acidosis (DRTA) is defined as hyperchloremic, non-anion gap metabolic acidosis with impaired urinary acid excretion in the presence of a normal or moderately reduced glomerular filtration rate. Failure in urinary acid excretion results from reduced H+ secretion by intercalated cells in the distal nephron. This results in decreased excretion of NH4+ and other acids collectively referred as titratable acids while urine pH is typically above 5.5 in the face of systemic acidosis. The clinical phenotype in patients with DRTA is characterized by stunted growth with bone abnormalities in children as well as nephrocalcinosis and nephrolithiasis that develop as the consequence of hypercalciuria, hypocitraturia, and relatively alkaline urine. Hypokalemia is a striking finding that accounts for muscle weakness and requires continued treatment together with alkali-based therapies. This review will focus on the mechanisms responsible for impaired acid excretion and urinary potassium wastage, the clinical features, and diagnostic approaches of hypokalemic DRTA, both inherited and acquired.
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Kurtz I. Renal Tubular Acidosis: H +/Base and Ammonia Transport Abnormalities and Clinical Syndromes. Adv Chronic Kidney Dis 2018; 25:334-350. [PMID: 30139460 PMCID: PMC6128697 DOI: 10.1053/j.ackd.2018.05.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Renal tubular acidosis (RTA) represents a group of diseases characterized by (1) a normal anion gap metabolic acidosis; (2) abnormalities in renal HCO3- absorption or new renal HCO3- generation; (3) changes in renal NH4+, Ca2+, K+, and H2O homeostasis; and (4) extrarenal manifestations that provide etiologic diagnostic clues. The focus of this review is to give a general overview of the pathogenesis of the various clinical syndromes causing RTA with a particular emphasis on type I (hypokalemic distal RTA) and type II (proximal) RTA while reviewing their pathogenesis from a physiological "bottom-up" approach. In addition, the factors involved in the generation of metabolic acidosis in both type I and II RTA are reviewed highlighting the importance of altered renal ammonia production/partitioning and new HCO3- generation. Our understanding of the underlying tubular transport and extrarenal abnormalities has significantly improved since the first recognition of RTA as a clinical entity because of significant advances in clinical acid-base chemistry, whole tubule and single-cell H+/base transport, and the molecular characterization of the various transporters and channels that are functionally affected in patients with RTA. Despite these advances, additional studies are needed to address the underlying mechanisms involved in hypokalemia, altered ammonia production/partitioning, hypercalciuria, nephrocalcinosis, cystic abnormalities, and CKD progression in these patients.
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Affiliation(s)
- Ira Kurtz
- Division of Nephrology, David Geffen School of Medicine, and Brain Research Institute, UCLA, Los Angeles, CA.
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Bazúa-Valenti S, Rojas-Vega L, Castañeda-Bueno M, Barrera-Chimal J, Bautista R, Cervantes-Pérez LG, Vázquez N, Plata C, Murillo-de-Ozores AR, González-Mariscal L, Ellison DH, Riccardi D, Bobadilla NA, Gamba G. The Calcium-Sensing Receptor Increases Activity of the Renal NCC through the WNK4-SPAK Pathway. J Am Soc Nephrol 2018; 29:1838-1848. [PMID: 29848507 DOI: 10.1681/asn.2017111155] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 04/10/2018] [Indexed: 01/07/2023] Open
Abstract
Background Hypercalciuria can result from activation of the basolateral calcium-sensing receptor (CaSR), which in the thick ascending limb of Henle's loop controls Ca2+ excretion and NaCl reabsorption in response to extracellular Ca2+ However, the function of CaSR in the regulation of NaCl reabsorption in the distal convoluted tubule (DCT) is unknown. We hypothesized that CaSR in this location is involved in activating the thiazide-sensitive NaCl cotransporter (NCC) to prevent NaCl loss.Methods We used a combination of in vitro and in vivo models to examine the effects of CaSR on NCC activity. Because the KLHL3-WNK4-SPAK pathway is involved in regulating NaCl reabsorption in the DCT, we assessed the involvement of this pathway as well.Results Thiazide-sensitive 22Na+ uptake assays in Xenopus laevis oocytes revealed that NCC activity increased in a WNK4-dependent manner upon activation of CaSR with Gd3+ In HEK293 cells, treatment with the calcimimetic R-568 stimulated SPAK phosphorylation only in the presence of WNK4. The WNK4 inhibitor WNK463 also prevented this effect. Furthermore, CaSR activation in HEK293 cells led to phosphorylation of KLHL3 and WNK4 and increased WNK4 abundance and activity. Finally, acute oral administration of R-568 in mice led to the phosphorylation of NCC.Conclusions Activation of CaSR can increase NCC activity via the WNK4-SPAK pathway. It is possible that activation of CaSR by Ca2+ in the apical membrane of the DCT increases NaCl reabsorption by NCC, with the consequent, well known decrease of Ca2+ reabsorption, further promoting hypercalciuria.
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Affiliation(s)
- Silvana Bazúa-Valenti
- Molecular Physiology Unit, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico.,Department of Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - Lorena Rojas-Vega
- Department of Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - María Castañeda-Bueno
- Department of Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - Jonatan Barrera-Chimal
- Molecular Physiology Unit, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | | | | | - Norma Vázquez
- Molecular Physiology Unit, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Consuelo Plata
- Department of Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - Adrián R Murillo-de-Ozores
- Molecular Physiology Unit, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico.,Department of Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - Lorenza González-Mariscal
- Department of Physiology, Biophysics and Neuroscience, Center for Research and Advanced Studies (Cinvestav), Mexico City, Mexico
| | - David H Ellison
- Department of Medicine, Oregon Health and Science University, Portland, Oregon.,Renal Section, Veterans Administration Portland Health Care System, Portland, Oregon
| | - Daniela Riccardi
- School of Biosciences, Cardiff University, Cardiff, United Kingdom; and
| | - Norma A Bobadilla
- Molecular Physiology Unit, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico.,Department of Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - Gerardo Gamba
- Molecular Physiology Unit, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico; .,Department of Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico.,Tecnológico de Monterrey, Escuela de Medicina y Ciencias de la Salud, Monterrey, Nuevo León, Mexico
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Walker RW, Zhang S, Coleman-Barnett JA, Hamm LL, Hering-Smith KS. Calcium receptor signaling and citrate transport. Urolithiasis 2018; 46:409-418. [PMID: 29383416 DOI: 10.1007/s00240-018-1035-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 01/10/2018] [Indexed: 01/22/2023]
Abstract
The calcium sensing receptor (CaSR) in the distal nephron decreases the propensity for calcium stones. Here we investigate if the apical CaSR in the proximal tubule also prevents stone formation acting via regulation of apical dicarboxylate and citrate transport. Urinary citrate, partially reabsorbed as a dicarboxylate in the proximal tubule lumen, inhibits stone formation by complexing calcium. We previously demonstrated a novel apical calcium-sensitive dicarboxylate transport system in OK proximal tubule cells. This calcium-sensitive process has the potential to modulate the amount of citrate available to complex increased urinary calcium. Using isotope labeled succinate uptake in OK cells along with various pharmacologic tools we examined whether the CaSR alters apical dicarboxylate transport and through which signal transduction pathways this occurs. Our results indicate that in the proximal tubule CaSR adjusts apical dicarboxylate transport, and does so via a CaSR → Gq → PKC signaling pathway. Thus, the CaSR may decrease the propensity for stone formation via actions in both proximal and distal nephron segments.
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Affiliation(s)
- Ryan W Walker
- Nephrology and Hypertension 8545, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, LA, 70112, USA
| | - Shijia Zhang
- Nephrology and Hypertension 8545, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, LA, 70112, USA
| | - Joycelynn A Coleman-Barnett
- Nephrology and Hypertension 8545, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, LA, 70112, USA
| | - L Lee Hamm
- Nephrology and Hypertension 8545, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, LA, 70112, USA
| | - Kathleen S Hering-Smith
- Nephrology and Hypertension 8545, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, LA, 70112, USA.
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Hoorn EJ, Severs D. Autophagy and renal epithelial transport: eat to survive. Kidney Int 2017; 91:1003-1005. [PMID: 28407874 DOI: 10.1016/j.kint.2017.01.033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 01/09/2017] [Indexed: 10/19/2022]
Abstract
Autophagy is an adaptive cellular response to "stress" in which proteins are targeted for lysosomal degradation. Using a combined proteomics and microscopy approach, Khositseth et al. show that autophagy contributes to the downregulation of the water channel aquaporin-2 in response to hypercalcemia. This commentary discusses the role of autophagy in renal epithelial transport, and explores whether autophagy may also contribute to chronic kidney disease once it becomes dysfunctional.
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Affiliation(s)
- Ewout J Hoorn
- Department of Internal Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, Rotterdam, Netherlands.
| | - David Severs
- Department of Internal Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, Rotterdam, Netherlands
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Pathophysiology, diagnosis and treatment of inherited distal renal tubular acidosis. J Nephrol 2017; 31:511-522. [DOI: 10.1007/s40620-017-0447-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 09/21/2017] [Indexed: 10/18/2022]
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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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Piret SE, Olinger E, Reed AAC, Nesbit MA, Hough TA, Bentley L, Devuyst O, Cox RD, Thakker RV. A mouse model for inherited renal fibrosis associated with endoplasmic reticulum stress. Dis Model Mech 2017; 10:773-786. [PMID: 28325753 PMCID: PMC5483009 DOI: 10.1242/dmm.029488] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 03/02/2017] [Indexed: 12/12/2022] Open
Abstract
Renal fibrosis is a common feature of renal failure resulting from multiple etiologies, including diabetic nephropathy, hypertension and inherited renal disorders. However, the mechanisms of renal fibrosis are incompletely understood and we therefore explored these by establishing a mouse model for a renal tubular disorder, referred to as autosomal dominant tubulointerstitial kidney disease (ADTKD) due to missense uromodulin (UMOD) mutations (ADTKD-UMOD). ADTKD-UMOD, which is associated with retention of mutant uromodulin in the endoplasmic reticulum (ER) of renal thick ascending limb cells, is characterized by hyperuricemia, interstitial fibrosis, inflammation and renal failure, and we used targeted homologous recombination to generate a knock-in mouse model with an ADTKD-causing missense cysteine to arginine uromodulin mutation (C125R). Heterozygous and homozygous mutant mice developed reduced uric acid excretion, renal fibrosis, immune cell infiltration and progressive renal failure, with decreased maturation and excretion of uromodulin, due to its retention in the ER. The ER stress marker 78 kDa glucose-regulated protein (GRP78) was elevated in cells expressing mutant uromodulin in heterozygous and homozygous mutant mice, and this was accompanied, both in vivo and ex vivo, by upregulation of two unfolded protein response pathways in primary thick ascending limb cells from homozygous mutant mice. However, this did not lead to an increase in apoptosis in vivo. Thus, we have developed a novel mouse model for renal fibrosis, which will be a valuable resource to decipher the mechanisms linking uromodulin mutations with ER stress and renal fibrosis. Summary: A mouse model for renal fibrosis caused by uromodulin mutations reveals roles for ER stress and the unfolded protein response.
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Affiliation(s)
- Sian E Piret
- Academic Endocrine Unit, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Headington, Oxford OX3 7LJ, UK
| | - Eric Olinger
- Institute of Physiology, University of Zurich, Zurich CH-8057, Switzerland
| | - Anita A C Reed
- Academic Endocrine Unit, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Headington, Oxford OX3 7LJ, UK
| | - M Andrew Nesbit
- Academic Endocrine Unit, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Headington, Oxford OX3 7LJ, UK.,School of Biomedical Sciences, University of Ulster, Coleraine BT52 1SA, UK
| | - Tertius A Hough
- MRC Mammalian Genetics Unit and Mary Lyon Centre, MRC Harwell Institute, Harwell Science and Innovation Campus, Oxfordshire OX11 0RD, UK
| | - Liz Bentley
- MRC Mammalian Genetics Unit and Mary Lyon Centre, MRC Harwell Institute, Harwell Science and Innovation Campus, Oxfordshire OX11 0RD, UK
| | - Olivier Devuyst
- Institute of Physiology, University of Zurich, Zurich CH-8057, Switzerland
| | - Roger D Cox
- MRC Mammalian Genetics Unit and Mary Lyon Centre, MRC Harwell Institute, Harwell Science and Innovation Campus, Oxfordshire OX11 0RD, UK
| | - Rajesh V Thakker
- Academic Endocrine Unit, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Headington, Oxford OX3 7LJ, UK
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Kitay AM, Geibel JP. Stomach and Bone. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1033:97-131. [DOI: 10.1007/978-3-319-66653-2_6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Roszko KL, Bi RD, Mannstadt M. Autosomal Dominant Hypocalcemia (Hypoparathyroidism) Types 1 and 2. Front Physiol 2016; 7:458. [PMID: 27803672 PMCID: PMC5067375 DOI: 10.3389/fphys.2016.00458] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2016] [Accepted: 09/23/2016] [Indexed: 12/15/2022] Open
Abstract
Extracellular calcium is essential for life and its concentration in the blood is maintained within a narrow range. This is achieved by a feedback loop that receives input from the calcium-sensing receptor (CASR), expressed on the surface of parathyroid cells. In response to low ionized calcium, the parathyroids increase secretion of parathyroid hormone (PTH) which increases serum calcium. The CASR is also highly expressed in the kidneys, where it regulates the reabsorption of calcium from the primary filtrate. Autosomal dominant hypocalcemia (ADH) type 1 is caused by heterozygous activating mutations in the CASR which increase the sensitivity of the CASR to extracellular ionized calcium. Consequently, PTH synthesis and secretion are suppressed at normal ionized calcium concentrations. Patients present with hypocalcemia, hyperphosphatemia, low magnesium levels, and low or low-normal levels of PTH. Urinary calcium excretion is typically increased due to the decrease in circulating PTH concentrations and by the activation of the renal tubular CASR. Therapeutic attempts using CASR antagonists (calcilytics) to treat ADH are currently under investigation. Recently, heterozygous mutations in the alpha subunit of the G protein G11 (Gα11) have been identified in patients with ADH, and this has been classified as ADH type 2. ADH2 mutations lead to a gain-of-function of Gα11, a key mediator of CASR signaling. Therefore, the mechanism of hypocalcemia appears similar to that of activating mutations in the CASR, namely an increase in the sensitivity of parathyroid cells to extracellular ionized calcium. Studies of activating mutations in the CASR and gain-of-function mutations in Gα11 can help define new drug targets and improve medical management of patients with ADH types 1 and 2.
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Affiliation(s)
- Kelly L Roszko
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School Boston, MA, USA
| | - Ruiye D Bi
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School Boston, MA, USA
| | - Michael Mannstadt
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School Boston, MA, USA
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Abstract
Calcium is an important ion in cell signaling, hormone regulation, and bone health. Its regulation is complex and intimately connected to that of phosphate homeostasis. Both ions are maintained at appropriate levels to maintain the extracellular to intracellular gradients, allow for mineralization of bone, and to prevent extra skeletal and urinary calcification. The homeostasis involves the target organs intestine, parathyroid glands, kidney, and bone. Multiple hormones converge to regulate the extracellular calcium level: parathyroid hormone, vitamin D (principally 25(OH)D or 1,25(OH)2D), fibroblast growth factor 23, and α-klotho. Fine regulation of calcium homeostasis occurs in the thick ascending limb and collecting tubule segments via actions of the calcium sensing receptor and several channels/transporters. The kidney participates in homeostatic loops with bone, intestine, and parathyroid glands. Initially in the course of progressive kidney disease, the homeostatic response maintains serum levels of calcium and phosphorus in the desired range, and maintains neutral balance. However, once the kidneys are no longer able to appropriately respond to hormones and excrete calcium and phosphate, positive balance ensues leading to adverse cardiac and skeletal abnormalities. © 2016 American Physiological Society. Compr Physiol 6:1781-1800, 2016.
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Affiliation(s)
- Sharon M Moe
- Division of Nephrology, Indiana University School of Medicine, Roudebush Veterans Administration Medical Center, Indianapolis, Indiana.,Section of Nephrology, Roudebush Veterans Administration Medical Center, Indianapolis, Indiana
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van Loon EPM, Little R, Prehar S, Bindels RJM, Cartwright EJ, Hoenderop JGJ. Calcium Extrusion Pump PMCA4: A New Player in Renal Calcium Handling? PLoS One 2016; 11:e0153483. [PMID: 27101128 PMCID: PMC4839660 DOI: 10.1371/journal.pone.0153483] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 03/17/2016] [Indexed: 11/19/2022] Open
Abstract
Calcium (Ca2+) is vital for multiple processes in the body, and maintenance of the electrolyte concentration is required for everyday physiological function. In the kidney, and more specifically, in the late distal convoluted tubule and connecting tubule, the fine-tuning of Ca2+ reabsorption from the pro-urine takes place. Here, Ca2+ enters the epithelial cell via the transient receptor potential vanilloid receptor type 5 (TRPV5) channel, diffuses to the basolateral side bound to calbindin-D28k and is extruded to the blood compartment via the Na+/Ca2+ exchanger 1 (NCX1) and the plasma membrane Ca2+ ATPase (PMCA). Traditionally, PMCA1 was considered to be the primary Ca2+ pump in this process. However, in recent studies TRPV5-expressing tubules were shown to highly express PMCA4. Therefore, PMCA4 may have a predominant role in renal Ca2+ handling. This study aimed to elucidate the role of PMCA4 in Ca2+ homeostasis by characterizing the Ca2+ balance, and renal and duodenal Ca2+-related gene expression in PMCA4 knockout mice. The daily water intake of PMCA4 knockout mice was significantly lower compared to wild type littermates. There was no significant difference in serum Ca2+ level or urinary Ca2+ excretion between groups. In addition, renal and duodenal mRNA expression levels of Ca2+-related genes, including TRPV5, TRPV6, calbindin-D28k, calbindin-D9k, NCX1 and PMCA1 were similar in wild type and knockout mice. Serum FGF23 levels were significantly increased in PMCA4 knockout mice. In conclusion, PMCA4 has no discernible role in normal renal Ca2+ handling as no urinary Ca2+ wasting was observed. Further investigation of the exact role of PMCA4 in the distal convoluted tubule and connecting tubule is required.
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Affiliation(s)
- Ellen P. M. van Loon
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, The Netherlands
| | - Robert Little
- Institute of Cardiovascular Sciences, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, United Kingdom
| | - Sukhpal Prehar
- Institute of Cardiovascular Sciences, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, United Kingdom
| | - René J. M. Bindels
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, The Netherlands
| | - Elizabeth J. Cartwright
- Institute of Cardiovascular Sciences, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, United Kingdom
| | - Joost G. J. Hoenderop
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, The Netherlands
- * E-mail:
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43
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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: 67] [Impact Index Per Article: 8.4] [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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Graca JAZ, Schepelmann M, Brennan SC, Reens J, Chang W, Yan P, Toka H, Riccardi D, Price SA. Comparative expression of the extracellular calcium-sensing receptor in the mouse, rat, and human kidney. Am J Physiol Renal Physiol 2015; 310:F518-33. [PMID: 26661650 DOI: 10.1152/ajprenal.00208.2015] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 11/30/2015] [Indexed: 11/22/2022] Open
Abstract
The calcium-sensing receptor (CaSR) was cloned over 20 years ago and functionally demonstrated to regulate circulating levels of parathyroid hormone by maintaining physiological serum ionized calcium concentration ([Ca(2+)]). The receptor is highly expressed in the kidney; however, intrarenal and intraspecies distribution remains controversial. Recently, additional functions of the CaSR receptor in the kidney have emerged, including parathyroid hormone-independent effects. It is therefore critical to establish unequivocally the localization of the CaSR in the kidney to relate this to its proposed physiological roles. In this study, we determined CaSR expression in mouse, rat, and human kidneys using in situ hybridization, immunohistochemistry (using 8 different commercially available and custom-made antibodies), and proximity ligation assays. Negative results in mice with kidney-specific CaSR ablation confirmed the specificity of the immunohistochemistry signal. Both in situ hybridization and immunohistochemistry showed CaSR expression in the thick ascending limb, distal tubule, and collecting duct of all species, with the thick ascending limb showing the highest levels. Within the collecting ducts, there was significant heterogeneity of expression between cell types. In the proximal tubule, lower levels of immunoreactivity were detected by immunohistochemistry and proximity ligation assays. Proximity ligation assays were the only technique to demonstrate expression within glomeruli. This study demonstrated CaSR expression throughout the kidney with minimal discrepancy between species but with significant variation in the levels of expression between cell and tubule types. These findings clarify the intrarenal distribution of the CaSR and enable elucidation of the full physiological roles of the receptor within this organ.
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Affiliation(s)
- J A Z Graca
- Pathology Sciences, AstraZeneca R&D, Macclesfield, United Kingdom; School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - M Schepelmann
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - S C Brennan
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - J Reens
- Pathology Sciences, AstraZeneca R&D, Macclesfield, United Kingdom
| | - W Chang
- Department of Medicine, UCSF School of Medicine, San Francisco, California
| | - P Yan
- Division of Nephrology, Beth Israel Deaconess Medical Center, Boston, Massachusetts; and
| | - H Toka
- Division of Nephrology and Hyperension, Eastern Virginia Medical School, Norfolk, Virginia
| | - D Riccardi
- School of Biosciences, Cardiff University, Cardiff, United Kingdom;
| | - S A Price
- Pathology Sciences, AstraZeneca R&D, Macclesfield, United Kingdom
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Abstract
The H(+) concentration in human blood is kept within very narrow limits, ~40 nmol/L, despite the fact that dietary metabolism generates acid and base loads that are added to the systemic circulation throughout the life of mammals. One of the primary functions of the kidney is to maintain the constancy of systemic acid-base chemistry. The kidney has evolved the capacity to regulate blood acidity by performing three key functions: (i) reabsorb HCO3(-) that is filtered through the glomeruli to prevent its excretion in the urine; (ii) generate a sufficient quantity of new HCO3(-) to compensate for the loss of HCO3(-) resulting from dietary metabolic H(+) loads and loss of HCO3(-) in the urea cycle; and (iii) excrete HCO3(-) (or metabolizable organic anions) following a systemic base load. The ability of the kidney to perform these functions requires that various cell types throughout the nephron respond to changes in acid-base chemistry by modulating specific ion transport and/or metabolic processes in a coordinated fashion such that the urine and renal vein chemistry is altered appropriately. The purpose of the article is to provide the interested reader with a broad review of a field that began historically ~60 years ago with whole animal studies, and has evolved to where we are currently addressing questions related to kidney acid-base regulation at the single protein structure/function level.
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Affiliation(s)
- Ira Kurtz
- Division of Nephrology, David Geffen School of Medicine, Los Angeles, CA; Brain Research Institute, UCLA, Los Angeles, CA
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Takenaka T, Inoue T, Miyazaki T, Nishiyama A, Ishii N, Hayashi M, Suzuki H. Antialbuminuric actions of calcilytics in the remnant kidney. Am J Physiol Renal Physiol 2015; 309:F216-26. [PMID: 26017971 DOI: 10.1152/ajprenal.00003.2015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Hyperphosphatemia accelerates the progression of chronic kidney diseases. In the present study, the effects of ronacaleret, a calcilytic agent, on renal injury were assessed in the following four groups of rats: 5/6-nephrectomized Wistar rats as a control (C group), rats treated with ronacaleret (3 mg·kg(-1)·day(-1); R group), rats treated with calcitriol (30 ng·kg(-1)·day(-1); V group), and rats treated with both ronacaleret and calcitriol (R + V group). Three months later, rats were euthanized under anesthesia, and the remnant kidneys were harvested for analysis. Albuminuria was lower in the R and V groups than in the C group (P < 0.05). Creatinine clearance was elevated in the R and V groups compared with the C group (P < 0.05). Serum Ca(2+) and renal ANG II were higher in the R + V group than in the C group (P < 0.05 for each), and serum phosphate was reduced in the R group compared with the C group (P < 0.05). Fibroblast growth factor-23 was lower in the R group and higher in the V and R + V groups than in the C group. However, parathyroid hormone did not differ significantly among the four groups. Renal klotho expression was elevated in the R and V groups compared with the C group (P < 0.05). The present data indicate that ronacaleret preserves klotho expression and renal function with reductions in serum phosphate and albuminuria in 5/6-nephrectomized rats. Our findings demonstrate that vitamin D prevents declines in klotho expression and renal function, suppressing albuminuria.
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Affiliation(s)
- Tsuneo Takenaka
- International University of Health and Welfare, Minato, Tokyo, Japan;
| | | | | | | | - Naohito Ishii
- Kitasato University, Sagamihara, Kanagawa, Japan; and
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Singh A, Ashraf A. Hypercalcemic crisis induced by calcium carbonate. Clin Kidney J 2015; 5:288-91. [PMID: 25874082 PMCID: PMC4393470 DOI: 10.1093/ckj/sfs060] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2011] [Accepted: 04/23/2012] [Indexed: 12/23/2022] Open
Abstract
We report a rare case of drug-induced hypercalcemic crisis in an elderly male resulting from calcium-containing supplements facilitated by thiazide diuretic and angiotensin-converting enzyme inhibitor. A 61-year-old male presented with hypercalcemic crisis along with renal insufficiency and metabolic alkalosis, mimicking the ‘calcium-alkali syndrome’. The patient responded to aggressive intravenous hydration along with emergent hemodialysis and salmon calcitonin. He did not have hyperparathyroidism or malignancy. History revealed an average daily intake of only 1200 mg of calcium carbonate along with vitamin D 1000 U/day over an extended period of time. The patient completely recovered in 3 days and had normal serum calcium, parathyroid hormone and phosphorous level at 3-month follow-up. The case highlights the life-threatening perils of indiscriminate and often excessive intake of calcium-containing supplements in an appropriate clinical setting. We also briefly discuss the epidemiology, clinical and laboratory features along with the recent advances in the understanding of the pathophysiology of calcium-alkali syndrome.
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Affiliation(s)
| | - Ambika Ashraf
- Division of Pediatric Endocrinology , University of Alabama , Birmingham, AL , USA
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48
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Edwards A. Regulation of calcium reabsorption along the rat nephron: a modeling study. Am J Physiol Renal Physiol 2015; 308:F553-66. [DOI: 10.1152/ajprenal.00577.2014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
We expanded a mathematical model of transepithelial transport along the rat nephron to include the transport of Ca2+ and probe the impact of calcium-sensing mechanisms on Ca2+ reabsorption. The model nephron extends from the medullary thick ascending limb (mTAL) to the inner medullary collecting duct (IMCD). Our model reproduces several experimental findings, such as measurements of luminal Ca2+ concentrations in cortical tubules, and the effects of furosemide or deletion of the transient receptor potential channel vanilloid subtype 5 (TRPV5) on urinary Ca2+ excretion. In vitro microperfusion of rat TAL has demonstrated that activation of the calcium-sensing receptor CaSR lowers the TAL permeability to Ca2+, PCaTAL (Loupy A, Ramakrishnan SK, Wootla B, Chambrey R, de la Faille R, Bourgeois S, Bruneval P, Mandet C, Christensen EI, Faure H, Cheval L, Laghmani K, Collet C, Eladari D, Dodd RH, Ruat M, Houillier P. J Clin Invest 122: 3355, 2012). Our results suggest that this regulatory mechanism significantly impacts renal Ca2+ handling: when plasma Ca2+ concentration ([Ca2+]) is raised by 10%, the CaSR-mediated reduction in PCaTAL per se is predicted to enhance urinary Ca2+ excretion by ∼30%. If high [Ca2+] also induces renal outer medullary potassium (ROMK) inhibition, urinary Ca2+ excretion is further raised. In vitro, increases in luminal [Ca2+] have been shown to activate H+-ATPase pumps in the outer medullary CD and to lower the water permeability of IMCD. Our model suggests that if these responses exhibit the sigmoidal dependence on luminal [Ca2+] that is characteristic of CaSR, then the impact of elevated Ca2+ levels in the CD on urinary volume and pH remains limited. Finally, our model suggests that CaSR inhibitors could significantly reduce urinary Ca2+ excretion in hypoparathyroidism, thereby reducing the risk of calcium stone formation.
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Affiliation(s)
- Aurélie Edwards
- Sorbonne Universités, Université Pierre et Marie Curie Université Paris 06, Institut National de la Santé et de la Recherche Médicale, Université Paris Descartes, Sorbonne Paris Cité, UMRS 1138, Centre National de la Recherche Scientifique ERL 8228, Centre de Recherche des Cordeliers, Paris, France
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Tudpor K, van der Eerden BCJ, Jongwattanapisan P, Roelofs JJTH, van Leeuwen JPTM, Bindels RJM, Hoenderop JGJ. Thrombin receptor deficiency leads to a high bone mass phenotype by decreasing the RANKL/OPG ratio. Bone 2015; 72:14-22. [PMID: 25460576 DOI: 10.1016/j.bone.2014.11.004] [Citation(s) in RCA: 18] [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: 08/21/2014] [Revised: 10/26/2014] [Accepted: 11/10/2014] [Indexed: 12/25/2022]
Abstract
Thrombin and its receptor (TR) are, respectively, expressed in osteoclasts and osteoblasts. However, their physiological roles on bone metabolism have not been fully elucidated. Here we investigated the bone microarchitecture by micro-computed tomography (μCT) and demonstrated increased trabecular and cortical bone mass in femurs of TR KO mice compared to WT littermates. Trabecular thickness and connectivity were significantly enhanced. The physiological role of TR on both inorganic and organic phases of bone is illustrated by a significant increase in BMD and a decrease in urinary deoxypyridinoline (DPD) crosslink concentration in TR KO mice. Moreover, TR KO cortical bone expanded and had a higher polar moment of inertia (J), implying stronger bone. Bone histomorphometry illustrated unaltered osteoblast and osteoclast number and surface in femoral metaphyses, indicating that thrombin/TR regulates osteoblasts and osteoclasts at functional levels. Serum analysis showed a decrease in RANKL and an increase in osteoprotegerin (OPG) levels and reflected a reduced RANKL/OPG ratio in the TR KO group. In vitro experiments using MC3T3 pre-osteoblasts demonstrated a TR-dependent stimulatory effect of thrombin on the RANKL/OPG ratio. This effect was blocked by TR antagonist and p42/p44-ERK inhibitor. In addition, thrombin also intensified p42/p44-ERK expression and phosphorylation. In conclusion, the thrombin/TR system maintains normal bone remodeling by activating RANKL and limiting OPG synthesis by osteoblasts through the p42/44-ERK signaling pathway. Consequently, TR deficiency inhibits osteoclastogenesis, resulting in a high bone mass phenotype.
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Affiliation(s)
- Kukiat Tudpor
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, The Netherlands
| | | | - Prapaporn Jongwattanapisan
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, The Netherlands
| | - Joris J T H Roelofs
- Department of Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | | | - René J M Bindels
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, The Netherlands
| | - Joost G J Hoenderop
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, The Netherlands.
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The G allele of CaSR R990G polymorphism increases susceptibility to urolithiasis and hypercalciuria: evidences from a comprehensive meta-analysis. BIOMED RESEARCH INTERNATIONAL 2015; 2015:958207. [PMID: 25705702 PMCID: PMC4331470 DOI: 10.1155/2015/958207] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Revised: 10/04/2014] [Accepted: 10/06/2014] [Indexed: 12/31/2022]
Abstract
Background. The calcium-sensing receptor gene (CaSR) is a candidate to explain urolithiasis. A number of case-control studies were conducted to investigate associations between CaSR polymorphisms with risks of hypercalciuria and urolithiasis in humans. But the results were still inconsistent. Methods. A meta-analysis was performed to address this issue. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to estimate the strength of associations between CaSR polymorphisms and the risk of urolithiasis. The pooled standardized mean difference (SMD) with 95% CI was used for the meta-analysis of CaSR polymorphisms and urine calcium concentration. Results. For urolithiasis association, the SS genotype of A986S polymorphism was a risk factor for urolithiasis in Asians and PHPT patients, but a protective factor in Caucasians. The GG genotype of R990 polymorphism was associated with an increased risk of urolithiasis, especially in Caucasians and healthy population. Regarding urine calcium concentration association, individuals with the G allele had a higher level of urine calcium than the noncarriers. Conclusions. This meta-analysis revealed that the G allele of CaSR R990G polymorphism increases susceptibility to urolithiasis and hypercalciuria. The A986S and Q1011E polymorphisms were associated with urolithiasis and hypercalciuria in specific populations.
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