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Read ML, Brookes K, Zha L, Manivannan S, Kim J, Kocbiyik M, Fletcher A, Gorvin CM, Firth G, Fruhwirth GO, Nicola JP, Jhiang S, Ringel MD, Campbell MJ, Sunassee K, Blower PJ, Boelaert K, Nieto HR, Smith VE, McCabe CJ. Combined Vorinostat and Chloroquine Inhibit Sodium-Iodide Symporter Endocytosis and Enhance Radionuclide Uptake In Vivo. Clin Cancer Res 2024; 30:1352-1366. [PMID: 37921808 PMCID: PMC7615786 DOI: 10.1158/1078-0432.ccr-23-2043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 09/12/2023] [Accepted: 11/01/2023] [Indexed: 11/04/2023]
Abstract
PURPOSE Patients with aggressive thyroid cancer are frequently failed by the central therapy of ablative radioiodide (RAI) uptake, due to reduced plasma membrane (PM) localization of the sodium/iodide symporter (NIS). We aimed to understand how NIS is endocytosed away from the PM of human thyroid cancer cells, and whether this was druggable in vivo. EXPERIMENTAL DESIGN Informed by analysis of endocytic gene expression in patients with aggressive thyroid cancer, we used mutagenesis, NanoBiT interaction assays, cell surface biotinylation assays, RAI uptake, and NanoBRET to understand the mechanisms of NIS endocytosis in transformed cell lines and patient-derived human primary thyroid cells. Systemic drug responses were monitored via 99mTc pertechnetate gamma counting and gene expression in BALB/c mice. RESULTS We identified an acidic dipeptide within the NIS C-terminus that mediates binding to the σ2 subunit of the Adaptor Protein 2 (AP2) heterotetramer. We discovered that the FDA-approved drug chloroquine (CQ) modulates NIS accumulation at the PM in a functional manner that is AP2 dependent. In vivo, CQ treatment of BALB/c mice significantly enhanced thyroidal uptake of 99mTc pertechnetate in combination with the histone deacetylase (HDAC) inhibitor vorinostat/SAHA, accompanied by increased thyroidal NIS mRNA. Bioinformatic analyses validated the clinical relevance of AP2 genes with disease-free survival in RAI-treated DTC, enabling construction of an AP2 gene-related risk score classifier for predicting recurrence. CONCLUSIONS NIS internalization is specifically druggable in vivo. Our data, therefore, provide new translatable potential for improving RAI therapy using FDA-approved drugs in patients with aggressive thyroid cancer. See related commentary by Lechner and Brent, p. 1220.
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Affiliation(s)
- Martin L. Read
- Institute of Metabolism and Systems Research (IMSR), and Centre of Endocrinology, Diabetes and Metabolism (CEDAM), University of Birmingham, Birmingham, UK
| | - Katie Brookes
- Institute of Metabolism and Systems Research (IMSR), and Centre of Endocrinology, Diabetes and Metabolism (CEDAM), University of Birmingham, Birmingham, UK
| | - Ling Zha
- Institute of Metabolism and Systems Research (IMSR), and Centre of Endocrinology, Diabetes and Metabolism (CEDAM), University of Birmingham, Birmingham, UK
| | - Selvambigai Manivannan
- Institute of Metabolism and Systems Research (IMSR), and Centre of Endocrinology, Diabetes and Metabolism (CEDAM), University of Birmingham, Birmingham, UK
| | - Jana Kim
- School of Biomedical Engineering & Imaging Sciences, King’s College London, London, UK
| | - Merve Kocbiyik
- Institute of Metabolism and Systems Research (IMSR), and Centre of Endocrinology, Diabetes and Metabolism (CEDAM), University of Birmingham, Birmingham, UK
| | - Alice Fletcher
- Institute of Metabolism and Systems Research (IMSR), and Centre of Endocrinology, Diabetes and Metabolism (CEDAM), University of Birmingham, Birmingham, UK
| | - Caroline M. Gorvin
- Institute of Metabolism and Systems Research (IMSR), and Centre of Endocrinology, Diabetes and Metabolism (CEDAM), University of Birmingham, Birmingham, UK
| | - George Firth
- School of Biomedical Engineering & Imaging Sciences, King’s College London, London, UK
| | - Gilbert O. Fruhwirth
- Comprehensive Cancer Centre, School of Cancer and Pharmaceutical Sciences, King's College London, Guy's Campus, London, UK
| | - Juan P. Nicola
- Departamento de Bioquímica Clínica (CIBICI-CONICET), Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Sissy Jhiang
- Divison of Endocrinology, Diabetes, and Metabolism and Cancer Biology Program, The Ohio State University College of Medicine and Comprehensive Cancer Center, Columbus, Ohio, USA
| | - Matthew D. Ringel
- Divison of Endocrinology, Diabetes, and Metabolism and Cancer Biology Program, The Ohio State University College of Medicine and Comprehensive Cancer Center, Columbus, Ohio, USA
| | - Moray J. Campbell
- Department of Pharmaceutics and Pharmaceutical Chemistry, College of Pharmacy at The Ohio State University, Columbus, Ohio, USA
| | - Kavitha Sunassee
- School of Biomedical Engineering & Imaging Sciences, King’s College London, London, UK
| | - Philip J. Blower
- School of Biomedical Engineering & Imaging Sciences, King’s College London, London, UK
| | - Kristien Boelaert
- Institute of Applied Health Research, University of Birmingham, Birmingham, UK
| | - Hannah R. Nieto
- Institute of Metabolism and Systems Research (IMSR), and Centre of Endocrinology, Diabetes and Metabolism (CEDAM), University of Birmingham, Birmingham, UK
| | - Vicki E. Smith
- Institute of Metabolism and Systems Research (IMSR), and Centre of Endocrinology, Diabetes and Metabolism (CEDAM), University of Birmingham, Birmingham, UK
| | - Christopher J. McCabe
- Institute of Metabolism and Systems Research (IMSR), and Centre of Endocrinology, Diabetes and Metabolism (CEDAM), University of Birmingham, Birmingham, UK
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2
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Thompson MD, Percy ME, Cole DEC, Bichet DG, Hauser AS, Gorvin CM. G protein-coupled receptor (GPCR) gene variants and human genetic disease. Crit Rev Clin Lab Sci 2024:1-30. [PMID: 38497103 DOI: 10.1080/10408363.2023.2286606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 11/19/2023] [Indexed: 03/19/2024]
Abstract
Genetic variations in the genes encoding G protein-coupled receptors (GPCRs) can disrupt receptor structure and function, which can result in human genetic diseases. Disease-causing mutations have been reported in at least 55 GPCRs for more than 66 monogenic diseases in humans. The spectrum of pathogenic and likely pathogenic variants includes loss of function variants that decrease receptor signaling on one extreme and gain of function that may result in biased signaling or constitutive activity, originally modeled on prototypical rhodopsin GPCR variants identified in retinitis pigmentosa, on the other. GPCR variants disrupt ligand binding, G protein coupling, accessory protein function, receptor desensitization and receptor recycling. Next generation sequencing has made it possible to identify variants of uncertain significance (VUS). We discuss variants in receptors known to result in disease and in silico strategies for disambiguation of VUS such as sorting intolerant from tolerant and polymorphism phenotyping. Modeling of variants has contributed to drug development and precision medicine, including drugs that target the melanocortin receptor in obesity and interventions that reverse loss of gonadotropin-releasing hormone receptor from the cell surface in idiopathic hypogonadotropic hypogonadism. Activating and inactivating variants of the calcium sensing receptor (CaSR) gene that are pathogenic in familial hypocalciuric hypercalcemia and autosomal dominant hypocalcemia have enabled the development of calcimimetics and calcilytics. Next generation sequencing has continued to identify variants in GPCR genes, including orphan receptors, that contribute to human phenotypes and may have therapeutic potential. Variants of the CaSR gene, some encoding an arginine-rich region that promotes receptor phosphorylation and intracellular retention, have been linked to an idiopathic epilepsy syndrome. Agnostic strategies have identified variants of the pyroglutamylated RF amide peptide receptor gene in intellectual disability and G protein-coupled receptor 39 identified in psoriatic arthropathy. Coding variants of the G protein-coupled receptor L1 (GPR37L1) orphan receptor gene have been identified in a rare familial progressive myoclonus epilepsy. The study of the role of GPCR variants in monogenic, Mendelian phenotypes has provided the basis of modeling the significance of more common variants of pharmacogenetic significance.
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Affiliation(s)
- Miles D Thompson
- Krembil Brain Institute, Toronto Western Hospital, Toronto, ON, Canada
| | - Maire E Percy
- Departments of Physiology and Obstetrics & Gynaecology, University of Toronto, Toronto, ON, Canada
| | - David E C Cole
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Daniel G Bichet
- Department of Physiology and Medicine, Hôpital du Sacré-Coeur, Université de Montréal, QC, Canada
| | - Alexander S Hauser
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Caroline M Gorvin
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, Birmingham, West Midlands, UK
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3
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Hansen MS, Madsen K, Price M, Søe K, Omata Y, Zaiss MM, Gorvin CM, Frost M, Rauch A. Transcriptional reprogramming during human osteoclast differentiation identifies regulators of osteoclast activity. Bone Res 2024; 12:5. [PMID: 38263167 PMCID: PMC10806178 DOI: 10.1038/s41413-023-00312-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 11/08/2023] [Accepted: 12/15/2023] [Indexed: 01/25/2024] Open
Abstract
Enhanced osteoclastogenesis and osteoclast activity contribute to the development of osteoporosis, which is characterized by increased bone resorption and inadequate bone formation. As novel antiosteoporotic therapeutics are needed, understanding the genetic regulation of human osteoclastogenesis could help identify potential treatment targets. This study aimed to provide an overview of transcriptional reprogramming during human osteoclast differentiation. Osteoclasts were differentiated from CD14+ monocytes from eight female donors. RNA sequencing during differentiation revealed 8 980 differentially expressed genes grouped into eight temporal patterns conserved across donors. These patterns revealed distinct molecular functions associated with postmenopausal osteoporosis susceptibility genes based on RNA from iliac crest biopsies and bone mineral density SNPs. Network analyses revealed mutual dependencies between temporal expression patterns and provided insight into subtype-specific transcriptional networks. The donor-specific expression patterns revealed genes at the monocyte stage, such as filamin B (FLNB) and oxidized low-density lipoprotein receptor 1 (OLR1, encoding LOX-1), that are predictive of the resorptive activity of mature osteoclasts. The expression of differentially expressed G-protein coupled receptors was strong during osteoclast differentiation, and these receptors are associated with bone mineral density SNPs, suggesting that they play a pivotal role in osteoclast differentiation and activity. The regulatory effects of three differentially expressed G-protein coupled receptors were exemplified by in vitro pharmacological modulation of complement 5 A receptor 1 (C5AR1), somatostatin receptor 2 (SSTR2), and free fatty acid receptor 4 (FFAR4/GPR120). Activating C5AR1 enhanced osteoclast formation, while activating SSTR2 decreased the resorptive activity of mature osteoclasts, and activating FFAR4 decreased both the number and resorptive activity of mature osteoclasts. In conclusion, we report the occurrence of transcriptional reprogramming during human osteoclast differentiation and identified SSTR2 and FFAR4 as antiresorptive G-protein coupled receptors and FLNB and LOX-1 as potential molecular markers of osteoclast activity. These data can help future investigations identify molecular regulators of osteoclast differentiation and activity and provide the basis for novel antiosteoporotic targets.
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Affiliation(s)
- Morten S Hansen
- Molecular Endocrinology Laboratory (KMEB), Department of Endocrinology, Odense University Hospital, DK-5000, Odense C, Denmark
- Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark, DK-5000, Odense C, Denmark
- Clinical Cell Biology, Pathology Research Unit, Department of Clinical Research, University of Southern Denmark, DK-5000, Odense C, Denmark
| | - Kaja Madsen
- Molecular Endocrinology Laboratory (KMEB), Department of Endocrinology, Odense University Hospital, DK-5000, Odense C, Denmark
- Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark, DK-5000, Odense C, Denmark
| | - Maria Price
- Institute of Metabolism and Systems Research (IMSR) and Centre for Diabetes, Endocrinology and Metabolism (CEDAM), University of Birmingham, Birmingham, B15 2TT, UK
- Centre for Membrane Proteins and Receptors (COMPARE), Universities of Birmingham and Nottingham, Birmingham, B15 2TT, UK
| | - Kent Søe
- Clinical Cell Biology, Pathology Research Unit, Department of Clinical Research, University of Southern Denmark, DK-5000, Odense C, Denmark
- Department of Molecular Medicine, University of Southern Denmark, DK-5000, Odense C, Denmark
| | - Yasunori Omata
- Department of Orthopedic Surgery, Faculty of Medicine, The University of Tokyo, Tokyo, 113-8655, Japan
- Department of Internal Medicine 3, Rheumatology and Immunology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) and Universitätsklinikum Erlangen, D-91054, Erlangen, Germany
| | - Mario M Zaiss
- Department of Internal Medicine 3, Rheumatology and Immunology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) and Universitätsklinikum Erlangen, D-91054, Erlangen, Germany
- Deutsches Zentrum Immuntherapie (DZI), Friedrich-Alexander-University Erlangen-Nürnberg and Universitätsklinikum Erlangen, D-91054, Erlangen, Germany
| | - Caroline M Gorvin
- Institute of Metabolism and Systems Research (IMSR) and Centre for Diabetes, Endocrinology and Metabolism (CEDAM), University of Birmingham, Birmingham, B15 2TT, UK
- Centre for Membrane Proteins and Receptors (COMPARE), Universities of Birmingham and Nottingham, Birmingham, B15 2TT, UK
| | - Morten Frost
- Molecular Endocrinology Laboratory (KMEB), Department of Endocrinology, Odense University Hospital, DK-5000, Odense C, Denmark.
- Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark, DK-5000, Odense C, Denmark.
- Steno Diabetes Center Odense, Odense University Hospital, DK-5000, Odense C, Denmark.
| | - Alexander Rauch
- Molecular Endocrinology Laboratory (KMEB), Department of Endocrinology, Odense University Hospital, DK-5000, Odense C, Denmark.
- Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark, DK-5000, Odense C, Denmark.
- Steno Diabetes Center Odense, Odense University Hospital, DK-5000, Odense C, Denmark.
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4
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Howles SA, Gorvin CM, Cranston T, Rogers A, Gluck AK, Boon H, Gibson K, Rahman M, Root A, Nesbit MA, Hannan FM, Thakker RV. GNA11 Variants Identified in Patients with Hypercalcemia or Hypocalcemia. J Bone Miner Res 2023; 38:907-917. [PMID: 36970776 PMCID: PMC10947407 DOI: 10.1002/jbmr.4803] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 03/09/2023] [Accepted: 03/19/2023] [Indexed: 04/20/2023]
Abstract
Familial hypocalciuric hypercalcemia type 2 (FHH2) and autosomal dominant hypocalcemia type 2 (ADH2) are due to loss- and gain-of-function mutations, respectively, of the GNA11 gene that encodes the G protein subunit Gα11, a signaling partner of the calcium-sensing receptor (CaSR). To date, four probands with FHH2-associated Gα11 mutations and eight probands with ADH2-associated Gα11 mutations have been reported. In a 10-year period, we identified 37 different germline GNA11 variants in >1200 probands referred for investigation of genetic causes for hypercalcemia or hypocalcemia, comprising 14 synonymous, 12 noncoding, and 11 nonsynonymous variants. The synonymous and noncoding variants were predicted to be benign or likely benign by in silico analysis, with 5 and 3, respectively, occurring in both hypercalcemic and hypocalcemic individuals. Nine of the nonsynonymous variants (Thr54Met, Arg60His, Arg60Leu, Gly66Ser, Arg149His, Arg181Gln, Phe220Ser, Val340Met, Phe341Leu) identified in 13 probands have been reported to be FHH2- or ADH2-causing. Of the remaining nonsynonymous variants, Ala65Thr was predicted to be benign, and Met87Val, identified in a hypercalcemic individual, was predicted to be of uncertain significance. Three-dimensional homology modeling of the Val87 variant suggested it was likely benign, and expression of Val87 variant and wild-type Met87 Gα11 in CaSR-expressing HEK293 cells revealed no differences in intracellular calcium responses to alterations in extracellular calcium concentrations, consistent with Val87 being a benign polymorphism. Two noncoding region variants, a 40bp-5'UTR deletion and a 15bp-intronic deletion, identified only in hypercalcemic individuals, were associated with decreased luciferase expression in vitro but no alterations in GNA11 mRNA or Gα11 protein levels in cells from the patient and no abnormality in splicing of the GNA11 mRNA, respectively, confirming them to be benign polymorphisms. Thus, this study identified likely disease-causing GNA11 variants in <1% of probands with hypercalcemia or hypocalcemia and highlights the occurrence of GNA11 rare variants that are benign polymorphisms. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Sarah A. Howles
- Academic Endocrine Unit, Radcliffe Department of MedicineUniversity of OxfordOxfordUK
- Nuffield Department of Surgical SciencesUniversity of OxfordOxfordUK
| | - Caroline M. Gorvin
- Academic Endocrine Unit, Radcliffe Department of MedicineUniversity of OxfordOxfordUK
- Present address:
Institute of Metabolism and Systems Research, University of Birmingham, and Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health PartnersBirminghamUK
| | - Treena Cranston
- Oxford Molecular Genetics LaboratoryChurchill HospitalOxfordUK
| | - Angela Rogers
- Academic Endocrine Unit, Radcliffe Department of MedicineUniversity of OxfordOxfordUK
| | - Anna K. Gluck
- Academic Endocrine Unit, Radcliffe Department of MedicineUniversity of OxfordOxfordUK
| | - Hannah Boon
- Oxford Molecular Genetics LaboratoryChurchill HospitalOxfordUK
| | - Kate Gibson
- Oxford Molecular Genetics LaboratoryChurchill HospitalOxfordUK
| | - Mushtaqur Rahman
- Department of EndocrinologyNorthwick Park Hospital, North West London Hospitals NHS TrustHarrowUK
| | - Allen Root
- Department of EndocrinologyJohn Hopkins All Children's HospitalSt. PetersburgFloridaUSA
| | - M. Andrew Nesbit
- Academic Endocrine Unit, Radcliffe Department of MedicineUniversity of OxfordOxfordUK
- Biomedical Sciences Research InstituteUniversity of UlsterColeraineUK
| | - Fadil M. Hannan
- Academic Endocrine Unit, Radcliffe Department of MedicineUniversity of OxfordOxfordUK
- Nuffield Department of Women's & Reproductive HealthUniversity of OxfordOxfordUK
| | - Rajesh V. Thakker
- Academic Endocrine Unit, Radcliffe Department of MedicineUniversity of OxfordOxfordUK
- National Institute for Health Research Oxford Biomedical Research CentreOxfordUK
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5
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Xu W, Qadir MMF, Nasteska D, Mota de Sa P, Gorvin CM, Blandino-Rosano M, Evans CR, Ho T, Potapenko E, Veluthakal R, Ashford FB, Bitsi S, Fan J, Bhondeley M, Song K, Sure VN, Sakamuri SSVP, Schiffer L, Beatty W, Wyatt R, Frigo DE, Liu X, Katakam PV, Arlt W, Buck J, Levin LR, Hu T, Kolls J, Burant CF, Tomas A, Merrins MJ, Thurmond DC, Bernal-Mizrachi E, Hodson DJ, Mauvais-Jarvis F. Architecture of androgen receptor pathways amplifying glucagon-like peptide-1 insulinotropic action in male pancreatic β cells. Cell Rep 2023; 42:112529. [PMID: 37200193 PMCID: PMC10312392 DOI: 10.1016/j.celrep.2023.112529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 12/20/2022] [Accepted: 05/03/2023] [Indexed: 05/20/2023] Open
Abstract
Male mice lacking the androgen receptor (AR) in pancreatic β cells exhibit blunted glucose-stimulated insulin secretion (GSIS), leading to hyperglycemia. Testosterone activates an extranuclear AR in β cells to amplify glucagon-like peptide-1 (GLP-1) insulinotropic action. Here, we examined the architecture of AR targets that regulate GLP-1 insulinotropic action in male β cells. Testosterone cooperates with GLP-1 to enhance cAMP production at the plasma membrane and endosomes via: (1) increased mitochondrial production of CO2, activating the HCO3--sensitive soluble adenylate cyclase; and (2) increased Gαs recruitment to GLP-1 receptor and AR complexes, activating transmembrane adenylate cyclase. Additionally, testosterone enhances GSIS in human islets via a focal adhesion kinase/SRC/phosphatidylinositol 3-kinase/mammalian target of rapamycin complex 2 actin remodeling cascade. We describe the testosterone-stimulated AR interactome, transcriptome, proteome, and metabolome that contribute to these effects. This study identifies AR genomic and non-genomic actions that enhance GLP-1-stimulated insulin exocytosis in male β cells.
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Affiliation(s)
- Weiwei Xu
- Section of Endocrinology and Metabolism, John W. Deming Department of Medicine, Tulane University School of Medicine, New Orleans, LA 70112, USA; Southeast Louisiana Veterans Health Care System, New Orleans, LA 70119, USA
| | - M M Fahd Qadir
- Section of Endocrinology and Metabolism, John W. Deming Department of Medicine, Tulane University School of Medicine, New Orleans, LA 70112, USA; Southeast Louisiana Veterans Health Care System, New Orleans, LA 70119, USA; Tulane Center of Excellence in Sex-Based Biology & Medicine, New Orleans, LA 70112, USA
| | - Daniela Nasteska
- Institute of Metabolism and Systems Research and Centre for Membrane Proteins and Receptors, University of Birmingham, Birmingham B15 2TT, UK; Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham B15 2TT, UK
| | - Paula Mota de Sa
- Section of Endocrinology and Metabolism, John W. Deming Department of Medicine, Tulane University School of Medicine, New Orleans, LA 70112, USA; Southeast Louisiana Veterans Health Care System, New Orleans, LA 70119, USA; Tulane Center of Excellence in Sex-Based Biology & Medicine, New Orleans, LA 70112, USA
| | - Caroline M Gorvin
- Institute of Metabolism and Systems Research and Centre for Membrane Proteins and Receptors, University of Birmingham, Birmingham B15 2TT, UK; Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham B15 2TT, UK
| | - Manuel Blandino-Rosano
- Department of Internal Medicine, Division Endocrinology, Metabolism and Diabetes, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | - Charles R Evans
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Thuong Ho
- Department of Medicine, Division of Endocrinology, Diabetes & Metabolism, University of Wisconsin-Madison, Madison, WI, USA
| | - Evgeniy Potapenko
- Department of Medicine, Division of Endocrinology, Diabetes & Metabolism, University of Wisconsin-Madison, Madison, WI, USA
| | - Rajakrishnan Veluthakal
- Department of Molecular and Cellular Endocrinology, City of Hope Beckman Research Institute, Duarte, CA 91010, USA
| | - Fiona B Ashford
- Institute of Metabolism and Systems Research and Centre for Membrane Proteins and Receptors, University of Birmingham, Birmingham B15 2TT, UK; Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham B15 2TT, UK
| | - Stavroula Bitsi
- Division of Diabetes, Endocrinology & Metabolism, Section of Cell Biology and Functional Genomics, Imperial College London, London SW7 2AZ, UK
| | - Jia Fan
- Center for Cellular and Molecular Diagnostics, Department of Molecular & Cellular Biology, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Manika Bhondeley
- Section of Endocrinology and Metabolism, John W. Deming Department of Medicine, Tulane University School of Medicine, New Orleans, LA 70112, USA; Southeast Louisiana Veterans Health Care System, New Orleans, LA 70119, USA; Tulane Center of Excellence in Sex-Based Biology & Medicine, New Orleans, LA 70112, USA
| | - Kejing Song
- Center for Translational Research in Infection and Inflammation, John W. Deming Department of Medicine, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Venkata N Sure
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Siva S V P Sakamuri
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Lina Schiffer
- Institute of Metabolism and Systems Research and Centre for Membrane Proteins and Receptors, University of Birmingham, Birmingham B15 2TT, UK; Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham B15 2TT, UK
| | - Wandy Beatty
- Molecular Imaging Facility, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Rachael Wyatt
- Institute of Metabolism and Systems Research and Centre for Membrane Proteins and Receptors, University of Birmingham, Birmingham B15 2TT, UK; Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham B15 2TT, UK
| | - Daniel E Frigo
- Departments of Cancer Systems Imaging and Genitourinary Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA
| | - Xiaowen Liu
- Division of Biomedical Informatics and Genomics, John W. Deming Department of Medicine, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Prasad V Katakam
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Wiebke Arlt
- Institute of Metabolism and Systems Research and Centre for Membrane Proteins and Receptors, University of Birmingham, Birmingham B15 2TT, UK; Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham B15 2TT, UK; National Institute for Health Research Birmingham Biomedical Research Centre, University Hospitals Birmingham NHS Foundation Trust and University of Birmingham, Birmingham B15 2TH, UK
| | - Jochen Buck
- Department of Pharmacology, Weill Cornell Medicine, New York, NY 10021, USA
| | - Lonny R Levin
- Department of Pharmacology, Weill Cornell Medicine, New York, NY 10021, USA
| | - Tony Hu
- Center for Cellular and Molecular Diagnostics, Department of Molecular & Cellular Biology, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Jay Kolls
- Center for Translational Research in Infection and Inflammation, John W. Deming Department of Medicine, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Charles F Burant
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Alejandra Tomas
- Division of Diabetes, Endocrinology & Metabolism, Section of Cell Biology and Functional Genomics, Imperial College London, London SW7 2AZ, UK
| | - Matthew J Merrins
- Department of Medicine, Division of Endocrinology, Diabetes & Metabolism, University of Wisconsin-Madison, Madison, WI, USA; William S. Middleton Memorial Veterans Hospital, Madison, WI, USA
| | - Debbie C Thurmond
- Department of Molecular and Cellular Endocrinology, City of Hope Beckman Research Institute, Duarte, CA 91010, USA
| | - Ernesto Bernal-Mizrachi
- Department of Internal Medicine, Division Endocrinology, Metabolism and Diabetes, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | - David J Hodson
- Institute of Metabolism and Systems Research and Centre for Membrane Proteins and Receptors, University of Birmingham, Birmingham B15 2TT, UK; Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham B15 2TT, UK
| | - Franck Mauvais-Jarvis
- Section of Endocrinology and Metabolism, John W. Deming Department of Medicine, Tulane University School of Medicine, New Orleans, LA 70112, USA; Southeast Louisiana Veterans Health Care System, New Orleans, LA 70119, USA; Tulane Center of Excellence in Sex-Based Biology & Medicine, New Orleans, LA 70112, USA.
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6
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Jamaluddin A, Gorvin CM. RISING STARS: Targeting G protein-coupled receptors to regulate energy homeostasis. J Mol Endocrinol 2023; 70:e230014. [PMID: 36943057 PMCID: PMC10160555 DOI: 10.1530/jme-23-0014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 03/21/2023] [Indexed: 03/23/2023]
Abstract
G protein-coupled receptors (GPCRs) have a critical role in energy homeostasis, contributing to food intake, energy expenditure and glycaemic control. Dysregulation of energy expenditure can lead to metabolic syndrome (abdominal obesity, elevated plasma triglyceride, LDL cholesterol and glucose, and high blood pressure), which is associated with an increased risk of developing obesity, diabetes mellitus, non-alcoholic fatty liver disease and cardiovascular complications. As the prevalence of these chronic diseases continues to rise worldwide, there is an increased need to understand the molecular mechanisms by which energy expenditure is regulated to facilitate the development of effective therapeutic strategies to treat and prevent these conditions. In recent years, drugs targeting GPCRs have been the focus of efforts to improve treatments for type-2 diabetes and obesity, with GLP-1R agonists a particular success. In this review, we focus on nine GPCRs with roles in energy homeostasis that are current and emerging targets to treat obesity and diabetes. We discuss findings from pre-clinical models and clinical trials of drugs targeting these receptors and challenges that must be overcome before these drugs can be routinely used in clinics. We also describe new insights into how these receptors signal, including how accessory proteins, biased signalling, and complex spatial signalling could provide unique opportunities to develop more efficacious therapies with fewer side effects. Finally, we describe how combined therapies, in which multiple GPCRs are targeted, may improve clinical outcomes and reduce off-target effects.
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Affiliation(s)
- Aqfan Jamaluddin
- Institute of Metabolism and Systems Research (IMSR) and Centre for Diabetes, Endocrinology and Metabolism (CEDAM), University of Birmingham, Birmingham, UK
- Centre of Membrane Proteins and Receptors (COMPARE), Universities of Birmingham and Nottingham, Birmingham, UK
| | - Caroline M Gorvin
- Institute of Metabolism and Systems Research (IMSR) and Centre for Diabetes, Endocrinology and Metabolism (CEDAM), University of Birmingham, Birmingham, UK
- Centre of Membrane Proteins and Receptors (COMPARE), Universities of Birmingham and Nottingham, Birmingham, UK
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7
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Gorvin CM, Newey PJ, Thakker RV. Identification of prolactin receptor variants with diverse effects on receptor signalling. J Mol Endocrinol 2023; 70:e220164. [PMID: 36445946 PMCID: PMC7614258 DOI: 10.1530/jme-22-0164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 11/29/2022] [Indexed: 12/02/2022]
Abstract
The prolactin receptor (PRLR) signals predominantly through the JAK2-STAT5 pathway regulating multiple physiological functions relating to fertility, lactation, and metabolism. However, the molecular pathology and role of PRLR mutations and signalling are incompletely defined, with progress hampered by a lack of reported disease-associated PRLR variants. To date, two common germline PRLR variants are reported to demonstrate constitutive activity, with one, Ile146Leu, overrepresented in benign breast disease, while a rare activating variant, Asn492Ile, is reported to be associated with an increased incidence of prolactinoma. In contrast, an inactivating germline heterozygous PRLR variant (His188Arg) was reported in a kindred with hyperprolactinaemia, while an inactivating compound heterozygous PRLR variant (Pro269Leu/Arg171Stop) was identified in an individual with hyperprolactinaemia and agalactia. We hypothesised that additional rare germline PRLR variants, identified from large-scale sequencing projects (ExAC and GnomAD), may be associated with altered in vitro PRLR signalling activity. We therefore evaluated >300 previously uncharacterised non-synonymous, germline PRLR variants and selected 10 variants for in vitro analysis based on protein prediction algorithms, proximity to known functional domains and structural modelling. Five variants, including extracellular and intracellular domain variants, were associated with altered responses when compared to the wild-type receptor. These altered responses included loss- and gain-of-function activities related to STAT5 signalling, Akt and FOXO1 activity, as well as cell viability and apoptosis. These studies provide further insight into PRLR structure-function and indicate that rare germline PRLR variants may have diverse modulating effects on PRLR signalling, although the pathophysiologic relevance of such alterations remains to be defined.
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Affiliation(s)
- Caroline M Gorvin
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
- Oxford NIHR Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, UK
- Institute of Metabolism and Systems Research (IMSR) & Centre for Endocrinology, Diabetes and Metabolism (CEDAM), Birmingham Health Partners, University of Birmingham, Birmingham, UK
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, UK
| | - Paul J Newey
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
- Division of Molecular & Clinical Medicine (MCM), University of Dundee, Jacqui Wood Cancer Centre, Dundee, UK
| | - Rajesh V Thakker
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
- Oxford NIHR Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, UK
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8
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Gorvin CM. Recent advances in calcium-sensing receptor structures and signaling pathways. Prog Mol Biol Transl Sci 2023; 195:121-135. [PMID: 36707151 DOI: 10.1016/bs.pmbts.2022.06.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The calcium-sensing receptor (CaSR) is a class C GPCR that has a fundamental role in extracellular calcium homeostasis by regulating parathyroid hormone release and urinary calcium excretion. Germline mutations in the receptor cause disorders of calcium homeostasis and studies of the functional effects of these mutations has facilitated understanding of CaSR signaling and how allosteric modulators affect these responses. In the past year, five cryo-EM structures of the near full-length CaSR have been published, demonstrating how agonist-binding transmits changes in the CaSR extracellular domain to the transmembrane region to activate G proteins, and how allosteric modulators affect these structural dynamics. Additionally, several recent studies have identified CaSR interacting proteins that regulate CaSR signaling and trafficking and contribute to understanding how the receptor achieves rapid and diverse physiological responses.
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Affiliation(s)
- Caroline M Gorvin
- Centre of Membrane Proteins and Receptors (COMPARE), Universities of Birmingham and Nottingham, Birmingham, United Kingdom; Institute of Metabolism and Systems Research (IMSR) and Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, University of Birmingham, Birmingham, United Kingdom.
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9
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Hansen MS, Søe K, Christensen LL, Fernandez-Guerra P, Hansen NW, Wyatt RA, Martin C, Hardy RS, Andersen TL, Olesen JB, Hartmann B, Rosenkilde MM, Kassem M, Rauch A, Gorvin CM, Frost M. GIP reduces osteoclast activity and improves osteoblast survival in primary human bone cells. Eur J Endocrinol 2023; 188:6987865. [PMID: 36747334 DOI: 10.1093/ejendo/lvac004] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 10/26/2022] [Accepted: 11/19/2022] [Indexed: 01/18/2023]
Abstract
OBJECTIVE Drugs targeting the glucose-dependent insulinotropic polypeptide (GIP) receptor (GIPR) are emerging as treatments for type-2 diabetes and obesity. GIP acutely decreases serum markers of bone resorption and transiently increases bone formation markers in short-term clinical investigations. However, it is unknown whether GIP acts directly on bone cells to mediate these effects. Using a GIPR-specific antagonist, we aimed to assess whether GIP acts directly on primary human osteoclasts and osteoblasts. METHODS Osteoclasts were differentiated from human CD14+ monocytes and osteoblasts from human bone. GIPR expression was determined using RNA-seq in primary human osteoclasts and in situ hybridization in human femoral bone. Osteoclastic resorptive activity was assessed using microscopy. GIPR signaling pathways in osteoclasts and osteoblasts were assessed using LANCE cAMP and AlphaLISA phosphorylation assays, intracellular calcium imaging and confocal microscopy. The bioenergetic profile of osteoclasts was evaluated using Seahorse XF-96. RESULTS GIPR is robustly expressed in mature human osteoclasts. GIP inhibits osteoclastogenesis, delays bone resorption, and increases osteoclast apoptosis by acting upon multiple signaling pathways (Src, cAMP, Akt, p38, Akt, NFκB) to impair nuclear translocation of nuclear factor of activated T cells-1 (NFATc1) and nuclear factor-κB (NFκB). Osteoblasts also expressed GIPR, and GIP improved osteoblast survival. Decreased bone resorption and improved osteoblast survival were also observed after GIP treatment of osteoclast-osteoblast co-cultures. Antagonizing GIPR with GIP(3-30)NH2 abolished the effects of GIP on osteoclasts and osteoblasts. CONCLUSIONS GIP inhibits bone resorption and improves survival of human osteoblasts, indicating that drugs targeting GIPR may impair bone resorption, whilst preserving bone formation.
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Affiliation(s)
- Morten S Hansen
- Molecular Endocrinology Laboratory (KMEB), Department of Endocrinology, Odense University Hospital, Odense C DK-5000, Denmark
- Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark, Odense C DK-5000, Denmark
- Institute of Metabolism and Systems Research (IMSR) and Centre for Diabetes, Endocrinology and Metabolism (CEDAM), University of Birmingham, Birmingham B15 2TT, United Kingdom
- Centre for Membrane Proteins and Receptors (COMPARE), Universities of Birmingham and Nottingham, Birmingham B15 2TT, United Kingdom
| | - Kent Søe
- Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark, Odense C DK-5000, Denmark
- Clinical Cell Biology, Department of Pathology, Odense University Hospital, Odense C DK-5000, Denmark
- Department of Molecular Medicine, University of Southern Denmark, Odense C DK-5000, Denmark
| | - Line L Christensen
- Molecular Endocrinology Laboratory (KMEB), Department of Endocrinology, Odense University Hospital, Odense C DK-5000, Denmark
| | - Paula Fernandez-Guerra
- Molecular Endocrinology Laboratory (KMEB), Department of Endocrinology, Odense University Hospital, Odense C DK-5000, Denmark
| | - Nina W Hansen
- Molecular Endocrinology Laboratory (KMEB), Department of Endocrinology, Odense University Hospital, Odense C DK-5000, Denmark
| | - Rachael A Wyatt
- Institute of Metabolism and Systems Research (IMSR) and Centre for Diabetes, Endocrinology and Metabolism (CEDAM), University of Birmingham, Birmingham B15 2TT, United Kingdom
- Centre for Membrane Proteins and Receptors (COMPARE), Universities of Birmingham and Nottingham, Birmingham B15 2TT, United Kingdom
| | - Claire Martin
- Institute of Metabolism and Systems Research (IMSR) and Centre for Diabetes, Endocrinology and Metabolism (CEDAM), University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Rowan S Hardy
- Institute of Metabolism and Systems Research (IMSR) and Centre for Diabetes, Endocrinology and Metabolism (CEDAM), University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Thomas L Andersen
- Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark, Odense C DK-5000, Denmark
- Clinical Cell Biology, Department of Pathology, Odense University Hospital, Odense C DK-5000, Denmark
- Department of Molecular Medicine, University of Southern Denmark, Odense C DK-5000, Denmark
| | - Jacob B Olesen
- Clinical Cell Biology, Department of Pathology, Odense University Hospital, Odense C DK-5000, Denmark
| | - Bolette Hartmann
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen N DK-2200, Denmark
| | - Mette M Rosenkilde
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen N DK-2200, Denmark
| | - Moustapha Kassem
- Molecular Endocrinology Laboratory (KMEB), Department of Endocrinology, Odense University Hospital, Odense C DK-5000, Denmark
- Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark, Odense C DK-5000, Denmark
| | - Alexander Rauch
- Molecular Endocrinology Laboratory (KMEB), Department of Endocrinology, Odense University Hospital, Odense C DK-5000, Denmark
- Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark, Odense C DK-5000, Denmark
- Steno Diabetes Centre Odense, Odense University Hospital, Odense C DK-5000, Denmark
| | - Caroline M Gorvin
- Institute of Metabolism and Systems Research (IMSR) and Centre for Diabetes, Endocrinology and Metabolism (CEDAM), University of Birmingham, Birmingham B15 2TT, United Kingdom
- Centre for Membrane Proteins and Receptors (COMPARE), Universities of Birmingham and Nottingham, Birmingham B15 2TT, United Kingdom
| | - Morten Frost
- Molecular Endocrinology Laboratory (KMEB), Department of Endocrinology, Odense University Hospital, Odense C DK-5000, Denmark
- Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark, Odense C DK-5000, Denmark
- Steno Diabetes Centre Odense, Odense University Hospital, Odense C DK-5000, Denmark
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10
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Fenton CG, Crastin A, Martin CS, Suresh S, Montagna I, Hussain B, Naylor AJ, Jones SW, Hansen MS, Gorvin CM, Price M, Filer A, Cooper MS, Lavery GG, Raza K, Hardy RS. 11β-Hydroxysteroid Dehydrogenase Type 1 within Osteoclasts Mediates the Bone Protective Properties of Therapeutic Corticosteroids in Chronic Inflammation. Int J Mol Sci 2022; 23:7334. [PMID: 35806338 PMCID: PMC9266304 DOI: 10.3390/ijms23137334] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 06/23/2022] [Accepted: 06/29/2022] [Indexed: 02/02/2023] Open
Abstract
Therapeutic glucocorticoids (GCs) are powerful anti-inflammatory tools in the management of chronic inflammatory diseases such as rheumatoid arthritis (RA). However, their actions on bone in this context are complex. The enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) is a mediator of the anti-inflammatory actions of therapeutic glucocorticoids (GCs) in vivo. In this study we delineate the role of 11β-HSD1 in the effects of GC on bone during inflammatory polyarthritis. Its function was assessed in bone biopsies from patients with RA and osteoarthritis, and in primary osteoblasts and osteoclasts. Bone metabolism was assessed in the TNF-tg model of polyarthritis treated with oral GC (corticosterone), in animals with global (TNF-tg11βKO), mesenchymal (including osteoblast) (TNF-tg11βflx/tw2cre) and myeloid (including osteoclast) (TNF-tg11βflx/LysMcre) deletion. Bone parameters were assessed by micro-CT, static histomorphometry and serum metabolism markers. We observed a marked increase in 11β-HSD1 activity in bone in RA relative to osteoarthritis bone, whilst the pro-inflammatory cytokine TNFα upregulated 11β-HSD1 within osteoblasts and osteoclasts. In osteoclasts, 11β-HSD1 mediated the suppression of bone resorption by GCs. Whilst corticosterone prevented the inflammatory loss of trabecular bone in TNF-tg animals, counterparts with global deletion of 11β-HSD1 were resistant to these protective actions, characterised by increased osteoclastic bone resorption. Targeted deletion of 11β-HSD1 within osteoclasts and myeloid derived cells partially reproduced the GC resistant phenotype. These data reveal the critical role of 11β-HSD1 within bone and osteoclasts in mediating the suppression of inflammatory bone loss in response to therapeutic GCs in chronic inflammatory disease.
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Affiliation(s)
- Chloe G Fenton
- Institute for Metabolism and Systems Research, University of Birmingham, Birmingham B15 2TT, UK; (C.G.F.); (C.S.M.); (I.M.); (C.M.G.); (M.P.); (G.G.L.)
- Research into Inflammatory Arthritis Centre Versus Arthritis, Institute of Inflammation and Ageing, University of Birmingham, Birmingham B15 2TT, UK; (A.J.N.); (A.F.); (K.R.)
| | - Ana Crastin
- Institute of Clinical Science, University of Birmingham, Birmingham B15 2TT, UK; (A.C.); (S.S.); (B.H.)
| | - Claire S Martin
- Institute for Metabolism and Systems Research, University of Birmingham, Birmingham B15 2TT, UK; (C.G.F.); (C.S.M.); (I.M.); (C.M.G.); (M.P.); (G.G.L.)
| | - Saicharan Suresh
- Institute of Clinical Science, University of Birmingham, Birmingham B15 2TT, UK; (A.C.); (S.S.); (B.H.)
| | - Isabella Montagna
- Institute for Metabolism and Systems Research, University of Birmingham, Birmingham B15 2TT, UK; (C.G.F.); (C.S.M.); (I.M.); (C.M.G.); (M.P.); (G.G.L.)
| | - Bismah Hussain
- Institute of Clinical Science, University of Birmingham, Birmingham B15 2TT, UK; (A.C.); (S.S.); (B.H.)
| | - Amy J Naylor
- Research into Inflammatory Arthritis Centre Versus Arthritis, Institute of Inflammation and Ageing, University of Birmingham, Birmingham B15 2TT, UK; (A.J.N.); (A.F.); (K.R.)
| | - Simon W Jones
- MRC Arthritis Research UK Centre for Musculoskeletal Ageing Research, University of Birmingham, Edgbaston Campus, Birmingham B15 2TT, UK;
| | - Morten S Hansen
- Molecular Endocrinology Laboratory (KMEB), Department of Endocrinology, Odense University Hospital, DK-5000 Odense, Denmark;
| | - Caroline M Gorvin
- Institute for Metabolism and Systems Research, University of Birmingham, Birmingham B15 2TT, UK; (C.G.F.); (C.S.M.); (I.M.); (C.M.G.); (M.P.); (G.G.L.)
- Centre for Membrane Proteins and Receptors (COMPARE), Universities of Birmingham and Nottingham, Birmingham B15 2TT, UK
| | - Maria Price
- Institute for Metabolism and Systems Research, University of Birmingham, Birmingham B15 2TT, UK; (C.G.F.); (C.S.M.); (I.M.); (C.M.G.); (M.P.); (G.G.L.)
| | - Andrew Filer
- Research into Inflammatory Arthritis Centre Versus Arthritis, Institute of Inflammation and Ageing, University of Birmingham, Birmingham B15 2TT, UK; (A.J.N.); (A.F.); (K.R.)
- MRC Arthritis Research UK Centre for Musculoskeletal Ageing Research, University of Birmingham, Edgbaston Campus, Birmingham B15 2TT, UK;
| | - Mark S Cooper
- ANZAC Research Institute, The University of Sydney, Sydney, NSW 2006, Australia;
| | - Gareth G Lavery
- Institute for Metabolism and Systems Research, University of Birmingham, Birmingham B15 2TT, UK; (C.G.F.); (C.S.M.); (I.M.); (C.M.G.); (M.P.); (G.G.L.)
- MRC Arthritis Research UK Centre for Musculoskeletal Ageing Research, University of Birmingham, Edgbaston Campus, Birmingham B15 2TT, UK;
| | - Karim Raza
- Research into Inflammatory Arthritis Centre Versus Arthritis, Institute of Inflammation and Ageing, University of Birmingham, Birmingham B15 2TT, UK; (A.J.N.); (A.F.); (K.R.)
- MRC Arthritis Research UK Centre for Musculoskeletal Ageing Research, University of Birmingham, Edgbaston Campus, Birmingham B15 2TT, UK;
- Department of Rheumatology, Sandwell and West Birmingham NHS Trust, Birmingham B15 2TT, UK
| | - Rowan S Hardy
- Institute for Metabolism and Systems Research, University of Birmingham, Birmingham B15 2TT, UK; (C.G.F.); (C.S.M.); (I.M.); (C.M.G.); (M.P.); (G.G.L.)
- Research into Inflammatory Arthritis Centre Versus Arthritis, Institute of Inflammation and Ageing, University of Birmingham, Birmingham B15 2TT, UK; (A.J.N.); (A.F.); (K.R.)
- Institute of Clinical Science, University of Birmingham, Birmingham B15 2TT, UK; (A.C.); (S.S.); (B.H.)
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11
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Gorvin CM. The importance of functionally characterizing calcium-sensing receptor variants in individuals with hypercalcemia. J Endocr Soc 2022; 6:bvac052. [PMID: 35506149 PMCID: PMC9049104 DOI: 10.1210/jendso/bvac052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Indexed: 11/19/2022] Open
Affiliation(s)
- Caroline M Gorvin
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, B15 2TT, UK
- Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, B15 2TH, UK
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12
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Abstract
The causes of hypercalcaemia in the neonate and infant are varied, and often distinct from those in older children and adults. Hypercalcaemia presents clinically with a range of symptoms including failure to thrive, poor feeding, constipation, polyuria, irritability, lethargy, seizures and hypotonia. When hypercalcaemia is suspected, an accurate diagnosis will require an evaluation of potential causes (e.g. family history) and assessment for physical features (such as dysmorphology, or subcutaneous fat deposits), as well as biochemical measurements, including total and ionised serum calcium, serum phosphate, creatinine and albumin, intact parathyroid hormone (PTH), vitamin D metabolites and urinary calcium, phosphate and creatinine. The causes of neonatal hypercalcaemia can be classified into high or low PTH disorders. Disorders associated with high serum PTH include neonatal severe hyperparathyroidism, familial hypocalciuric hypercalcaemia and Jansen's metaphyseal chondrodysplasia. Conditions associated with low serum PTH include idiopathic infantile hypercalcaemia, Williams-Beuren syndrome and inborn errors of metabolism, including hypophosphatasia. Maternal hypocalcaemia and dietary factors and several rare endocrine disorders can also influence neonatal serum calcium levels. This review will focus on the common causes of hypercalcaemia in neonates and young infants, considering maternal, dietary, and genetic causes of calcium dysregulation. The clinical presentation and treatment of patients with these disorders will be discussed.
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Affiliation(s)
- Caroline M. Gorvin
- Institute of Metabolism and Systems Research and Centre for Endocrinology, Diabetes and Metabolism, University of Birmingham, Birmingham, B15 2TT UK ,Centre of Membrane Proteins and Receptors (COMPARE), Universities of Birmingham and Nottingham, Birmingham, B15 2TT UK
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13
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Abstract
Ghrelin is a peptide hormone secreted primarily by the stomach that acts upon the growth hormone secretagogue receptor (GHSR1), a G protein-coupled receptor whose functions include growth hormone secretion, appetite regulation, energy expenditure, regulation of adiposity, and insulin release. Following the discovery that GHSR1a stimulates food intake, receptor antagonists were developed as potential therapies to regulate appetite. However, despite reductions in signalling, the desired effects on appetite were absent. Studies in the past 15 years have demonstrated GHSR1a can interact with other transmembrane proteins, either by direct binding (i.e. heteromerisation) or via signalling cross-talk. These interactions have various effects on GHSR1a signalling including preferential coupling to one pathway (i.e. biased signalling), coupling to a unique G protein (G protein switching), suppression of GHSR1a signalling, and enhancement of signalling by both receptors. While many of these interactions have been shown in cells overexpressing the proteins of interest and remain to be verified in tissues, substantial evidence exists showing that GHSR1a and the dopamine receptor D1 (DRD1) form heteromers, which promote synaptic plasticity and formation of hippocampal memory. Additionally, a reduction in GHSR1a-DRD1 complexes in favour of establishment of GHSR1a-Aβ complexes correlates with Alzheimer's disease, indicating that GHSR1a heteromers may have pathological functions. Herein, we summarise the evidence published to date describing interactions between GHSR1a and transmembrane proteins, discuss the experimental strengths and limitations of these studies, describe the physiological evidence for each interaction, and address their potential as novel drug targets for appetite regulation, Alzheimer's disease, insulin secretion, and inflammation.
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Affiliation(s)
- Maria L Price
- Institute of Metabolism and Systems Research and Centre for Endocrinology, Diabetes and Metabolism, University of Birmingham, Birmingham, UK
- Centre of Membrane Proteins and Receptors (COMPARE), Universities of Birmingham and Nottingham, Birmingham, UK
| | - Cameron D Ley
- Institute of Metabolism and Systems Research and Centre for Endocrinology, Diabetes and Metabolism, University of Birmingham, Birmingham, UK
- Centre of Membrane Proteins and Receptors (COMPARE), Universities of Birmingham and Nottingham, Birmingham, UK
| | - Caroline M Gorvin
- Institute of Metabolism and Systems Research and Centre for Endocrinology, Diabetes and Metabolism, University of Birmingham, Birmingham, UK
- Centre of Membrane Proteins and Receptors (COMPARE), Universities of Birmingham and Nottingham, Birmingham, UK
- Correspondence should be addressed to C M Gorvin:
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14
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Lines KE, Gluck AK, Thongjuea S, Bountra C, Thakker RV, Gorvin CM. The bromodomain inhibitor JQ1+ reduces calcium-sensing receptor activity in pituitary cell lines. J Mol Endocrinol 2021; 67:83-94. [PMID: 34223822 PMCID: PMC8345903 DOI: 10.1530/jme-21-0030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 07/05/2021] [Indexed: 12/05/2022]
Abstract
Corticotrophinomas represent 10% of all surgically removed pituitary adenomas, however, current treatment options are often not effective, and there is a need for improved pharmacological treatments. Recently, JQ1+, a bromodomain inhibitor that promotes gene transcription by binding acetylated histone residues and recruiting transcriptional machinery, has been shown to reduce proliferation in a murine corticotroph cell line, AtT20. RNA-Seq analysis of AtT20 cells following treatment with JQ1+ identified the calcium-sensing receptor (CaSR) gene as significantly downregulated, which was subsequently confirmed using real-time PCR and Western blot analysis. CaSR is a G protein-coupled receptor that plays a central role in calcium homeostasis but can elicit non-calcitropic effects in multiple tissues, including the anterior pituitary where it helps regulate hormone secretion. However, in AtT20 cells, CaSR activates a tumour-specific cAMP pathway that promotes ACTH and PTHrP hypersecretion. We hypothesised that the Casr promoter may harbour binding sites for BET proteins, and using chromatin immunoprecipitation (ChIP)-sequencing demonstrated that the BET protein Brd3 binds to the promoter of the Casr gene. Assessment of CaSR signalling showed that JQ1+ significantly reduced Ca2+e-mediated increases in intracellular calcium (Ca2+i) mobilisation and cAMP signalling. However, the CaSR-negative allosteric modulator, NPS-2143, was unable to reduce AtT20 cell proliferation, indicating that reducing CaSR expression rather than activity is likely required to reduce pituitary cell proliferation. Thus, these studies demonstrate that reducing CaSR expression may be a viable option in the treatment of pituitary tumours. Moreover, current strategies to reduce CaSR activity, rather than protein expression for cancer treatments, may be ineffective.
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Affiliation(s)
- Kate E Lines
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford,UK
- Correspondence should be addressed to K E Lines or C M Gorvin: or
| | - Anna K Gluck
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford,UK
| | - Supat Thongjuea
- Centre for Computational Biology, MRC Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Oxford, UK
| | - Chas Bountra
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Rajesh V Thakker
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford,UK
| | - Caroline M Gorvin
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford,UK
- Institute of Metabolism and Systems Research and Centre for Endocrinology, Diabetes and Metabolism, University of Birmingham, Birmingham, UK
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, UK
- Correspondence should be addressed to K E Lines or C M Gorvin: or
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Abstract
The calcium-sensing receptor (CaSR) is a G protein-coupled receptor that plays a fundamental role in extracellular calcium (Ca2+e) homeostasis by regulating parathyroid hormone release and urinary calcium excretion. The CaSR has been described to activate all four G protein subfamilies (Gαq/11, Gαi/o, Gα12/13, Gαs), and mutations in the receptor that cause hyper/hypocalcaemia, have been described to bias receptor signalling. However, many of these studies are based on measurements of second messengers or gene transcription that occurs many steps downstream of receptor activation and can represent convergence points of several signalling pathways. Therefore, to assess CaSR-mediated G protein activation directly, we took advantage of a recently described NanoBiT G protein dissociation assay system. Our studies, performed in HEK293 cells stably expressing CaSR, demonstrate that Ca2+e stimulation activates all Gαq/11 family and several Gαi/o family proteins, although Gαz was not activated. CaSR stimulated dissociation of Gα12/13 and Gαs from Gβ-subunits, but this occurred at a slower rate than that of other Gα-subunits. Investigation of cDNA expression of G proteins in three tissues abundantly expressing CaSR, the parathyroids, kidneys and pancreas, showed Gα11, Gαz, Gαi1 and Gα13 genes were highly expressed in parathyroid tissue, indicating CaSR most likely activates Gα11 and Gαi1 in parathyroids. In kidney and pancreas, the majority of G proteins were similarly expressed, suggesting CaSR may activate multiple G proteins in these cells. Thus, these studies validate a single assay system that can be used to robustly assess CaSR variants and biased signalling and could be utilised in the development of new pharmacological compounds targeting CaSR.
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Affiliation(s)
- Hasnat Ali Abid
- Institute of Metabolism and Systems Research and Centre for Endocrinology, Diabetes and Metabolism, University of Birmingham, Birmingham, UK
| | - Asuka Inoue
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, Japan
| | - Caroline M Gorvin
- Institute of Metabolism and Systems Research and Centre for Endocrinology, Diabetes and Metabolism, University of Birmingham, Birmingham, UK
- Centre of Membrane Proteins and Receptors (COMPARE), Universities of Birmingham and Nottingham, UK
- Correspondence should be addressed to C M Gorvin:
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16
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Hannan FM, Stevenson M, Bayliss AL, Stokes VJ, Stewart M, Kooblall KG, Gorvin CM, Codner G, Teboul L, Wells S, Thakker RV. Ap2s1 mutation causes hypercalcaemia in mice and impairs interaction between calcium-sensing receptor and adaptor protein-2. Hum Mol Genet 2021; 30:880-892. [PMID: 33729479 PMCID: PMC8165646 DOI: 10.1093/hmg/ddab076] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 02/09/2021] [Accepted: 02/26/2021] [Indexed: 12/16/2022] Open
Abstract
Adaptor protein 2 (AP2), a heterotetrameric complex comprising AP2α, AP2β2, AP2μ2 and AP2σ2 subunits, is ubiquitously expressed and involved in endocytosis and trafficking of membrane proteins, such as the calcium-sensing receptor (CaSR), a G-protein coupled receptor that signals via Gα11. Mutations of CaSR, Gα11 and AP2σ2, encoded by AP2S1, cause familial hypocalciuric hypercalcaemia types 1–3 (FHH1–3), respectively. FHH3 patients have heterozygous AP2S1 missense Arg15 mutations (p.Arg15Cys, p.Arg15His or p.Arg15Leu) with hypercalcaemia, which may be marked and symptomatic, and occasional hypophosphataemia and osteomalacia. To further characterize the phenotypic spectrum and calcitropic pathophysiology of FHH3, we used CRISPR/Cas9 genome editing to generate mice harboring the AP2S1 p.Arg15Leu mutation, which causes the most severe FHH3 phenotype. Heterozygous (Ap2s1+/L15) mice were viable, and had marked hypercalcaemia, hypermagnesaemia, hypophosphataemia, and increases in alkaline phosphatase activity and fibroblast growth factor-23. Plasma 1,25-dihydroxyvitamin D was normal, and no alterations in bone mineral density or bone turnover were noted. Homozygous (Ap2s1L15/L15) mice invariably died perinatally. Co-immunoprecipitation studies showed that the AP2S1 p.Arg15Leu mutation impaired protein–protein interactions between AP2σ2 and the other AP2 subunits, and also with the CaSR. Cinacalcet, a CaSR positive allosteric modulator, decreased plasma calcium and parathyroid hormone concentrations in Ap2s1+/L15 mice, but had no effect on the diminished AP2σ2-CaSR interaction in vitro. Thus, our studies have established a mouse model that is representative for FHH3 in humans, and demonstrated that the AP2S1 p.Arg15Leu mutation causes a predominantly calcitropic phenotype, which can be ameliorated by treatment with cinacalcet.
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Affiliation(s)
- Fadil M Hannan
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 7LJ, UK.,Nuffield Department of Women's and Reproductive Health, University of Oxford, Oxford OX3 9DU, UK
| | - Mark Stevenson
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 7LJ, UK
| | - Asha L Bayliss
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 7LJ, UK
| | - Victoria J Stokes
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 7LJ, UK
| | - Michelle Stewart
- Mammalian Genetics Unit and Mary Lyon Centre, MRC Harwell Institute, Harwell Campus, Oxfordshire OX11 0RD, UK
| | - Kreepa G Kooblall
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 7LJ, UK
| | - Caroline M Gorvin
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 7LJ, UK
| | - Gemma Codner
- Mammalian Genetics Unit and Mary Lyon Centre, MRC Harwell Institute, Harwell Campus, Oxfordshire OX11 0RD, UK
| | - Lydia Teboul
- Mammalian Genetics Unit and Mary Lyon Centre, MRC Harwell Institute, Harwell Campus, Oxfordshire OX11 0RD, UK
| | - Sara Wells
- Mammalian Genetics Unit and Mary Lyon Centre, MRC Harwell Institute, Harwell Campus, Oxfordshire OX11 0RD, UK
| | - Rajesh V Thakker
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 7LJ, UK
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17
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Abstract
The calcium-sensing receptor (CaSR) is a class C G-protein-coupled receptor (GPCR) that plays a fundamental role in extracellular calcium homeostasis by regulating parathyroid hormone (PTH) release. Although the CaSR was identified over 25 years ago, new mechanistic details of how the CaSR controls PTH secretion have recently been uncovered demonstrating heteromerization and phosphate binding affect CaSR-mediated suppression of PTH release. In addition, understanding of how the CaSR performs diverse functions in different cellular contexts is just beginning to be elucidated, with new evidence of tissue-specific regulation, and endo-somal signaling. Insights into CaSR activation mechanisms and signaling bias have arisen from studies of CaSR mutations, which cause disorders of calcium homeostasis. Functional assessment of these mutations demonstrated the importance of the homodimer interface and transmembrane domain in biased signaling and showed CaSR mutations can facilitate G-protein-independent signaling. Population genetics studies have allowed a greater understanding of the prevalence of calcemic disorders and revealed new pathophysiological roles.
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Affiliation(s)
- Caroline M Gorvin
- Institute of Metabolism and Systems Research (IMSR) and Centre for Diabetes, Endocrinology and Metabolism (CEDAM), University of Birmingham, Birmingham, B15 2TT, UK
- Centre for Membrane Proteins and Receptors (COMPARE), Universities of Birmingham and Nottingham, B15 2TT, UK
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18
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Stevenson M, Pagnamenta AT, Reichart S, Philpott C, Lines KE, Gorvin CM, Lhotta K, Taylor JC, Thakker RV. Whole genome sequence analysis identifies a PAX2 mutation to establish a correct diagnosis for a syndromic form of hyperuricemia. Am J Med Genet A 2020; 182:2521-2528. [PMID: 32776440 PMCID: PMC7611017 DOI: 10.1002/ajmg.a.61814] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 07/04/2020] [Accepted: 07/07/2020] [Indexed: 01/13/2023]
Abstract
Hereditary hyperuricemia may occur as part of a syndromic disorder or as an isolated nonsyndromic disease, and over 20 causative genes have been identified. Here, we report the use of whole genome sequencing (WGS) to establish a diagnosis in a family in which individuals were affected with gout, hyperuricemia associated with reduced fractional excretion of uric acid, chronic kidney disease (CKD), and secondary hyperparathyroidism, that are consistent with familial juvenile hyperuricemic nephropathy (FJHN). However, single gene testing had not detected mutations in the uromodulin (UMOD) or renin (REN) genes, which cause approximately 30-90% of FJHN. WGS was therefore undertaken, and this identified a heterozygous c.226G>C (p.Gly76Arg) missense variant in the paired box gene 2 (PAX2) gene, which co-segregated with renal tubulopathy in the family. PAX2 mutations are associated with renal coloboma syndrome (RCS), which is characterized by abnormalities in renal structure and function, and anomalies of the optic nerve. Ophthalmological examination in two adult brothers affected with hyperuricemia, gout, and CKD revealed the presence of optic disc pits, consistent with optic nerve coloboma, thereby revising the diagnosis from FJHN to RCS. Thus, our results demonstrate the utility of WGS analysis in establishing the correct diagnosis in disorders with multiple etiologies.
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Affiliation(s)
- Mark Stevenson
- Oxford Centre for Diabetes, Endocrinology & Metabolism (OCDEM), Churchill Hospital, University of Oxford, Oxford, UK
| | | | - Silvia Reichart
- Department of Ophthalmology, Academic Teaching Hospital, Feldkirch, Austria
| | - Charlotte Philpott
- Oxford Centre for Diabetes, Endocrinology & Metabolism (OCDEM), Churchill Hospital, University of Oxford, Oxford, UK
| | - Kate E. Lines
- Oxford Centre for Diabetes, Endocrinology & Metabolism (OCDEM), Churchill Hospital, University of Oxford, Oxford, UK
| | | | - Caroline M. Gorvin
- Oxford Centre for Diabetes, Endocrinology & Metabolism (OCDEM), Churchill Hospital, University of Oxford, Oxford, UK
| | - Karl Lhotta
- Department of Internal Medicine III (Nephrology and Dialysis), Academic Teaching Hospital, Feldkirch, Austria
| | | | - Rajesh V. Thakker
- Oxford Centre for Diabetes, Endocrinology & Metabolism (OCDEM), Churchill Hospital, University of Oxford, Oxford, UK
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20
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Dershem R, Gorvin CM, Metpally RP, Krishnamurthy S, Smelser DT, Hannan FM, Carey DJ, Thakker RV, Breitwieser GE. Familial Hypocalciuric Hypercalcemia Type 1 and Autosomal-Dominant Hypocalcemia Type 1: Prevalence in a Large Healthcare Population. Am J Hum Genet 2020; 106:734-747. [PMID: 32386559 PMCID: PMC7273533 DOI: 10.1016/j.ajhg.2020.04.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 04/03/2020] [Indexed: 12/21/2022] Open
Abstract
The calcium-sensing receptor (CaSR) regulates serum calcium concentrations. CASR loss- or gain-of-function mutations cause familial hypocalciuric hypercalcemia type 1 (FHH1) or autosomal-dominant hypocalcemia type 1 (ADH1), respectively, but the population prevalence of FHH1 or ADH1 is unknown. Rare CASR variants were identified in whole-exome sequences from 51,289 de-identified individuals in the DiscovEHR cohort derived from a single US healthcare system. We integrated bioinformatics pathogenicity triage, mean serum Ca concentrations, and mode of inheritance to identify potential FHH1 or ADH1 variants, and we used a Sequence Kernel Association Test (SKAT) to identify rare variant-associated diseases. We identified predicted heterozygous loss-of-function CASR variants (6 different nonsense/frameshift variants and 12 different missense variants) in 38 unrelated individuals, 21 of whom were hypercalcemic. Missense CASR variants were identified in two unrelated hypocalcemic individuals. Functional studies showed that all hypercalcemia-associated missense variants impaired heterologous expression, plasma membrane targeting, and/or signaling, whereas hypocalcemia-associated missense variants increased expression, plasma membrane targeting, and/or signaling. Thus, 38 individuals with a genetic diagnosis of FHH1 and two individuals with a genetic diagnosis of ADH1 were identified in the 51,289 cohort, giving a prevalence in this population of 74.1 per 100,000 for FHH1 and 3.9 per 100,000 for ADH1. SKAT combining all nonsense, frameshift, and missense loss-of-function variants revealed associations with cardiovascular, neurological, and other diseases. In conclusion, FHH1 is a common cause of hypercalcemia, with prevalence similar to that of primary hyperparathyroidism, and is associated with altered disease risks, whereas ADH1 is a major cause of non-surgical hypoparathyroidism.
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Affiliation(s)
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- Regeneron Genetics Center, Tarrytown, NY 10591, USA
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21
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Gluck AK, Stevenson M, Falcone S, Inoue A, Breitwieser GE, Gorvin CM, Lines KE, Thakker RV. OR07-06 The Roles of GNAQ and GNA11 in Calcium-Sensing Receptor (CaSR) Signalling. J Endocr Soc 2020. [PMCID: PMC7207458 DOI: 10.1210/jendso/bvaa046.1321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The G-protein subunits Gα 11 and Gα q, which share >90% peptide sequence identity and are encoded by the GNA11 and GNAQ genes, respectively, mediate signalling by the calcium-sensing receptor (CaSR), a class C G-protein coupled receptor (GPCR) that regulates extracellular calcium (Ca2+e) homeostasis. Germline Gα 11 inactivating and activating mutations cause familial hypocalciuric hypercalcaemia type-2 (FHH2) and autosomal dominant hypocalcaemia type-2 (ADH2), respectively, but such Gα q mutations have not been reported. We therefore investigated the DiscovEHR cohort database, which has exomes from 51,289 patients with matched phenotyping data, for such GNAQ mutations. The DiscovEHR cohort was examined for rare GNAQ variants, which were transiently expressed in CaSR-expressing HEK293A Gα q/11 knockout cells, and their effects on CaSR-mediated intracellular calcium (Ca2+i) release and MAPK activity, in response to increasing concentrations of extracellular calcium were assessed using a nuclear factor of activated T-cells response element (NFAT-RE) luciferase reporter construct and a serum response element (SRE) luciferase reporter construct, respectively. Responses were compared to those of wild-type (WT), inactivating FHH2-associated GNA11 mutations (Leu135Gln and Phe220Ser), and engineered GNAQ mutations that were equivalent to the FHH2-causing GNA11 mutations. Gα q/11 protein expression was confirmed by Western blot analysis. Six rare missense GNAQ variants (Arg19Trp, Ala110Val, Gln299His, Ala302Ser, Ala331Thr, Val344Ile) were identified in DiscovEHR individuals, all of whom had mean plasma calcium values in the normal range (8.30–10.00 mg/dL). Functional characterisation of all six Gα q variants showed no significant difference to WT Gα q responses, thereby indicating that these variants are unlikely to be disease-causing mutations. In addition, the FHH2-causing GNA11 mutations (Leu135Gln and Phe220Ser) had significantly reduced responses, compared to WT Gα 11; however, this could be compensated by WT Gα q. GNAQ Leu135Gln and Phe220Ser, in contrast to their Gα 11 counterparts, showed no differences in protein expression or signalling responses when compared to WT Gα q. Our study, which provides mechanistic insights into the differences between Gα q and Gα 11, indicates that Gα q, unlike Gα 11, does not play a major role in the pathogenesis of FHH2 or ADH2.
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Hannan FM, Dharmaraj P, Gorvin CM, Soni A, Nelhans ND, Olesen MK, Boon H, Cranston T, Thakker RV. SAT-404 Neonatal Hypocalcemic Seizures in Offspring of a Mother with Familial Hypocalciuric Hypercalcemia Type 1 (FHH1). J Endocr Soc 2020. [PMCID: PMC7208433 DOI: 10.1210/jendso/bvaa046.729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Background: Familial hypocalciuric hypercalcemia type 1 (FHH1) is caused by loss-of-function mutations of the calcium-sensing receptor (CaSR), and considered to be a benign condition associated with mild-to-moderate hypercalcemia (1). However, the children of parents with FHH1 can develop a variety of disorders of calcium homeostasis in infancy. Objective: To further characterise the range of calcitropic phenotypes in the children of a mother with FHH1. Methods: We assessed a three generation FHH kindred by clinical, biochemical and mutational analysis following informed consent. Results: The kindred comprised a hypercalcemic male, his daughter who had hypercalcemia and hypocalciuria, and her four children, of whom two had asymptomatic hypercalcemia, one was normocalcemic, and one suffered from transient hypocalcemic seizures during infancy. The hypocalcemic infant had a serum calcium of 1.57 mmol/L (normal, 2.0-2.8) and PTH of 2.2 pmol/L (normal, 1.0-9.3) as a consequence of maternal hypercalcemia, and required treatment with I-V calcium gluconate infusions. Mutational analysis identified a novel heterozygous p.Ser448Pro CaSR variant in the hypercalcemic family members, but not in the children with hypocalcemia or normocalcemia. Three-dimensional modelling using a reported crystal structure of the dimeric CaSR showed the mutated Ser448 residue to be located in the CaSR extracellular domain, and predicted the p.Ser448Pro variant to disrupt a hydrogen bond interaction across the extracellular CaSR dimer interface. The variant Pro448 CaSR, when expressed in HEK293 cells, was shown to significantly impair CaSR-mediated intracellular calcium mobilisation and mitogen-activated protein kinase (MAPK) responses following stimulation with extracellular calcium, thereby demonstrating it to represent a loss-of-function mutation. Conclusion: These studies have identified a novel loss-of-function CaSR mutation which caused asymptomatic hypercalcemia in a mother and her children who had inherited the mutation. However, one child who did not inherit the mutation developed transient neonatal hypocalcemic seizures as a consequence of maternal hypercalcemia. These findings highlight the importance of assessing serum calcium and undertaking CaSR mutational analysis in the newborn offspring of a mother with FHH1. Reference: (1) 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(1): 33-51.
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Affiliation(s)
| | | | | | - Astha Soni
- Alder Hey Childrens Hospital, Liverpool, United Kingdom
| | | | | | - Hannah Boon
- Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - Treena Cranston
- Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
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23
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Dharmaraj P, Gorvin CM, Soni A, Nelhans ND, Olesen MK, Boon H, Cranston T, Thakker RV, Hannan FM. Neonatal Hypocalcemic Seizures in Offspring of a Mother With Familial Hypocalciuric Hypercalcemia Type 1 (FHH1). J Clin Endocrinol Metab 2020; 105:5801090. [PMID: 32150253 PMCID: PMC7096312 DOI: 10.1210/clinem/dgaa111] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 03/03/2020] [Indexed: 12/28/2022]
Abstract
CONTEXT Familial hypocalciuric hypercalcemia type 1 (FHH1) is caused by loss-of-function mutations of the calcium-sensing receptor (CaSR) and is considered a benign condition associated with mild-to-moderate hypercalcemia. However, the children of parents with FHH1 can develop a variety of disorders of calcium homeostasis in infancy. OBJECTIVE The objective of this work is to characterize the range of calcitropic phenotypes in the children of a mother with FHH1. METHODS A 3-generation FHH kindred was assessed by clinical, biochemical, and mutational analysis following informed consent. RESULTS The FHH kindred comprised a hypercalcemic man and his daughter who had hypercalcemia and hypocalciuria, and her 4 children, 2 of whom had asymptomatic hypercalcemia, 1 was normocalcemic, and 1 suffered from transient neonatal hypocalcemia and seizures. The hypocalcemic infant had a serum calcium of 1.57 mmol/L (6.28 mg/dL); normal, 2.0 to 2.8 mmol/L (8.0-11.2 mg/dL) and parathyroid hormone of 2.2 pmol/L; normal 1.0 to 9.3 pmol/L, and required treatment with intravenous calcium gluconate infusions. A novel heterozygous p.Ser448Pro CaSR variant was identified in the hypercalcemic individuals, but not the children with hypocalcemia or normocalcemia. Three-dimensional modeling predicted the p.Ser448Pro variant to disrupt a hydrogen bond interaction within the CaSR extracellular domain. The variant Pro448 CaSR, when expressed in HEK293 cells, significantly impaired CaSR-mediated intracellular calcium mobilization and mitogen-activated protein kinase responses following stimulation with extracellular calcium, thereby demonstrating it to represent a loss-of-function mutation. CONCLUSIONS Thus, children of a mother with FHH1 can develop hypercalcemia or transient neonatal hypocalcemia, depending on the underlying inherited CaSR mutation, and require investigations for serum calcium and CaSR mutations in early childhood.
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Affiliation(s)
- Poonam Dharmaraj
- Department of Paediatric Endocrinology, Alder Hey Children’s NHS Foundation Trust, Liverpool, UK
| | - Caroline M Gorvin
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
- Current Affiliation: The current affiliation of C.M.G. is Institute of Metabolism and Systems Research, University of Birmingham, and Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK
| | - Astha Soni
- Department of Paediatric Endocrinology, Alder Hey Children’s NHS Foundation Trust, Liverpool, UK
| | - Nick D Nelhans
- Department of Paediatrics, Wrexham Maelor Hospital, Wrexham, UK
| | - Mie K Olesen
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Hannah Boon
- Oxford Molecular Genetics Laboratory, Churchill Hospital, Oxford, UK
| | - Treena Cranston
- Oxford Molecular Genetics Laboratory, Churchill Hospital, Oxford, UK
| | - Rajesh V Thakker
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Fadil M Hannan
- Nuffield Department of Women’s and Reproductive Health, University of Oxford, Oxford, UK
- Correspondence and Reprint Requests: Fadil Hannan, MBChB, DPhil, Nuffield Department of Women’s and Reproductive Health, Level 3, Women’s Centre, John Radcliffe Hospital, Oxford OX3 9DU, UK. E-mail:
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24
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Onopiuk M, Eby B, Nesin V, Ngo P, Lerner M, Gorvin CM, Stokes VJ, Thakker RV, Brandi ML, Chang W, Humphrey MB, Tsiokas L, Lau K. Control of PTH secretion by the TRPC1 ion channel. JCI Insight 2020; 5:132496. [PMID: 32213715 PMCID: PMC7205425 DOI: 10.1172/jci.insight.132496] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 03/16/2020] [Indexed: 11/17/2022] Open
Abstract
Familial hypocalciuric hypercalcemia (FHH) is a genetic condition associated with hypocalciuria, hypercalcemia, and, in some cases, inappropriately high levels of circulating parathyroid hormone (PTH). FHH is associated with inactivating mutations in the gene encoding the Ca2+-sensing receptor (CaSR), a GPCR, and GNA11 encoding G protein subunit α 11 (Gα11), implicating defective GPCR signaling as the root pathophysiology for FHH. However, the downstream mechanism by which CaSR activation inhibits PTH production/secretion is incompletely understood. Here, we show that mice lacking the transient receptor potential canonical channel 1 (TRPC1) develop chronic hypercalcemia, hypocalciuria, and elevated PTH levels, mimicking human FHH. Ex vivo and in vitro studies revealed that TRPC1 serves a necessary and sufficient mediator to suppress PTH secretion from parathyroid glands (PTGs) downstream of CaSR in response to high extracellular Ca2+ concentration. Gα11 physically interacted with both the N- and C-termini of TRPC1 and enhanced CaSR-induced TRPC1 activity in transfected cells. These data identify TRPC1-mediated Ca2+ signaling as an essential component of the cellular apparatus controlling PTH secretion in the PTG downstream of CaSR.
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Affiliation(s)
| | - Bonnie Eby
- Department of Medicine, Division of Nephrology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | | | | | - Megan Lerner
- Department of Surgery, Oklahoma City, Oklahoma, USA
| | - Caroline M Gorvin
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Victoria J Stokes
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Rajesh V Thakker
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Maria Luisa Brandi
- Department of Biomedicals Sperimentals and Clinicals Sciences, Università degli Studi di Firenze and Fondazione FIRMO, Florence, Italy
| | - Wenhan Chang
- Endocrinology and Metabolism, Department of Medicine, UCSF, San Francisco, California, USA
| | - Mary Beth Humphrey
- Department of Medicine, Division of Rheumatology, Immunology, and Allergy, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA.,Department of Veterans Affairs, Oklahoma City, Oklahoma, USA
| | | | - Kai Lau
- Department of Medicine, Division of Nephrology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA.,Department of Veterans Affairs, Oklahoma City, Oklahoma, USA
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25
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Gorvin CM, Stokes VJ, Boon H, Cranston T, Glück AK, Bahl S, Homfray T, Aung T, Shine B, Lines KE, Hannan FM, Thakker RV. Activating Mutations of the G-protein Subunit α 11 Interdomain Interface Cause Autosomal Dominant Hypocalcemia Type 2. J Clin Endocrinol Metab 2020; 105:5671666. [PMID: 31820785 PMCID: PMC7048683 DOI: 10.1210/clinem/dgz251] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Accepted: 12/09/2019] [Indexed: 12/30/2022]
Abstract
CONTEXT Autosomal dominant hypocalcemia types 1 and 2 (ADH1 and ADH2) are caused by germline gain-of-function mutations of the calcium-sensing receptor (CaSR) and its signaling partner, the G-protein subunit α 11 (Gα 11), respectively. More than 70 different gain-of-function CaSR mutations, but only 6 different gain-of-function Gα 11 mutations are reported to date. METHODS We ascertained 2 additional ADH families and investigated them for CaSR and Gα 11 mutations. The effects of identified variants on CaSR signaling were evaluated by transiently transfecting wild-type (WT) and variant expression constructs into HEK293 cells stably expressing CaSR (HEK-CaSR), and measuring intracellular calcium (Ca2+i) and MAPK responses following stimulation with extracellular calcium (Ca2+e). RESULTS CaSR variants were not found, but 2 novel heterozygous germline Gα 11 variants, p.Gly66Ser and p.Arg149His, were identified. Homology modeling of these revealed that the Gly66 and Arg149 residues are located at the interface between the Gα 11 helical and GTPase domains, which is involved in guanine nucleotide binding, and this is the site of 3 other reported ADH2 mutations. The Ca2+i and MAPK responses of cells expressing the variant Ser66 or His149 Gα 11 proteins were similar to WT cells at low Ca2+e, but significantly increased in a dose-dependent manner following Ca2+e stimulation, thereby indicating that the p.Gly66Ser and p.Arg149His variants represent pathogenic gain-of-function Gα 11 mutations. Treatment of Ser66- and His149-Gα 11 expressing cells with the CaSR negative allosteric modulator NPS 2143 normalized Ca2+i and MAPK responses. CONCLUSION Two novel ADH2-causing mutations that highlight the Gα 11 interdomain interface as a hotspot for gain-of-function Gα 11 mutations have been identified.
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Affiliation(s)
- Caroline M Gorvin
- Academic Endocrine Unit, Radcliffe Department of Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), University of Oxford, Oxford, UK
- Oxford NIHR Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, UK
| | - Victoria J Stokes
- Academic Endocrine Unit, Radcliffe Department of Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), University of Oxford, Oxford, UK
- Oxford NIHR Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, UK
| | - Hannah Boon
- Oxford Molecular Genetics Laboratory, Churchill Hospital, Oxford, UK
| | - Treena Cranston
- Oxford Molecular Genetics Laboratory, Churchill Hospital, Oxford, UK
| | - Anna K Glück
- Academic Endocrine Unit, Radcliffe Department of Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), University of Oxford, Oxford, UK
| | - Shailini Bahl
- Department of Paediatrics, Ashford and St. Peter’s Hospitals NHS Foundation Trust, Surrey, UK
| | - Tessa Homfray
- Department of Clinical Genetics, St George’s University Hospital, London, UK
| | - Theingi Aung
- The Centre for Diabetes and Endocrinology, Royal Berkshire NHS Foundation Trust, Reading, UK
| | - Brian Shine
- Department of Clinical Biochemistry, John Radcliffe Hospital, Oxford University Hospitals NHS Trust, Oxford, UK
| | - Kate E Lines
- Academic Endocrine Unit, Radcliffe Department of Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), University of Oxford, Oxford, UK
| | - Fadil M Hannan
- Academic Endocrine Unit, Radcliffe Department of Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), University of Oxford, 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
- Oxford NIHR Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, UK
- Correspondence and Reprint Requests: Rajesh V. Thakker, Academic Endocrine Unit, Radcliffe Department of Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), Churchill Hospital, Oxford OX3 7LJ, United Kingdom. E-mail:
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Abstract
Twenty-five years have elapsed since the calcium-sensing receptor (CaSR) was first identified in bovine parathyroid and the receptor is now recognized as a fundamental contributor to extracellular Ca2+ (Ca2+ e) homeostasis, regulating parathyroid hormone release and urinary calcium excretion. The CaSR is a class C G-protein-coupled receptor (GPCR) that is functionally active as a homodimer and couples to multiple G-protein subtypes to activate intracellular signalling pathways. The importance of the CaSR in the regulation of Ca2+ e has been highlighted by the identification of >400 different germline loss- and gain-of-function CaSR mutations that give rise to disorders of Ca2+ e homeostasis. CaSR-inactivating mutations cause neonatal severe hyperparathyroidism, characterised by marked hypercalcaemia, skeletal demineralisation and failure to thrive in early infancy; and familial hypocalciuric hypercalcaemia, an often asymptomatic disorder associated with mild-moderately elevated serum calcium concentrations. Activating mutations are associated with autosomal dominant hypocalcaemia, which is occasionally associated with a Bartter's-like phenotype. Recent elucidation of the CaSR extracellular domain structure enabled the locations of CaSR mutations to be mapped and has revealed clustering in locations important for structural integrity, receptor dimerisation and ligand binding. Moreover, the study of disease-causing mutations has demonstrated that CaSR signals in a biased manner and have revealed specific residues important for receptor activation. This review presents the current understanding of the genetic landscape of CaSR mutations by summarising findings from clinical and functional studies of disease-associated mutations. It concludes with reflections on how recently uncovered signalling pathways may expand the understanding of calcium homeostasis disorders.
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Affiliation(s)
- Caroline M Gorvin
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, Birmingham, UK
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, UK
- Centre for Endocrinology, Diabetes and Metabolism (CEDAM), Birmingham Health Partners, Birmingham, UK
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27
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Gorvin CM, Loh NY, Stechman MJ, Falcone S, Hannan FM, Ahmad BN, Piret SE, Reed AA, Jeyabalan J, Leo P, Marshall M, Sethi S, Bass P, Roberts I, Sanderson J, Wells S, Hough TA, Bentley L, Christie PT, Simon MM, Mallon AM, Schulz H, Cox RD, Brown MA, Huebner N, Brown SD, Thakker RV. Mice with a Brd4 Mutation Represent a New Model of Nephrocalcinosis. J Bone Miner Res 2019; 34:1324-1335. [PMID: 30830987 PMCID: PMC6658219 DOI: 10.1002/jbmr.3695] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 01/26/2019] [Accepted: 02/05/2019] [Indexed: 12/30/2022]
Abstract
Nephrolithiasis (NL) and nephrocalcinosis (NC), which comprise renal calcification of the collecting system and parenchyma, respectively, have a multifactorial etiology with environmental and genetic determinants and affect ∼10% of adults by age 70 years. Studies of families with hereditary NL and NC have identified >30 causative genes that have increased our understanding of extracellular calcium homeostasis and renal tubular transport of calcium. However, these account for <20% of the likely genes that are involved, and to identify novel genes for renal calcification disorders, we investigated 1745 12-month-old progeny from a male mouse that had been treated with the chemical mutagen N-ethyl-N-nitrosourea (ENU) for radiological renal opacities. This identified a male mouse with renal calcification that was inherited as an autosomal dominant trait with >80% penetrance in 152 progeny. The calcification consisted of calcium phosphate deposits in the renal papillae and was associated with the presence of the urinary macromolecules osteopontin and Tamm-Horsfall protein, which are features found in Randall's plaques of patients with NC. Genome-wide mapping located the disease locus to a ∼30 Mbp region on chromosome 17A3.3-B3 and whole-exome sequence analysis identified a heterozygous mutation, resulting in a missense substitution (Met149Thr, M149T), in the bromodomain-containing protein 4 (BRD4). The mutant heterozygous (Brd4+/M149T ) mice, when compared with wild-type (Brd4+/+ ) mice, were normocalcemic and normophosphatemic, with normal urinary excretions of calcium and phosphate, and had normal bone turnover markers. BRD4 plays a critical role in histone modification and gene transcription, and cDNA expression profiling, using kidneys from Brd4+/M149T and Brd4+/+ mice, revealed differential expression of genes involved in vitamin D metabolism, cell differentiation, and apoptosis. Kidneys from Brd4+/M149T mice also had increased apoptosis at sites of calcification within the renal papillae. Thus, our studies have established a mouse model, due to a Brd4 Met149Thr mutation, for inherited NC. © 2019 American Society for Bone and Mineral Research.
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Affiliation(s)
- Caroline M Gorvin
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology, and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Nellie Y Loh
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology, and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Michael J Stechman
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology, and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Sara Falcone
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology, and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Fadil M Hannan
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology, and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.,Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, UK
| | - Bushra N Ahmad
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology, and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Sian E Piret
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology, and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Anita Ac Reed
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology, and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Jeshmi Jeyabalan
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology, and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Paul Leo
- Translational Genomics Group, Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Queensland University of Technology (QUT) at Translational Research Institute, Brisbane, Australia
| | - Mhairi Marshall
- Translational Genomics Group, Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Queensland University of Technology (QUT) at Translational Research Institute, Brisbane, Australia
| | - Siddharth Sethi
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council Harwell Institute, Harwell, UK
| | - Paul Bass
- Department of Cellular Pathology, Royal Free Hospital, London, UK
| | - Ian Roberts
- Department of Cellular Pathology, John Radcliffe Hospital, Oxford, UK
| | - Jeremy Sanderson
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council Harwell Institute, Harwell, UK
| | - Sara Wells
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council Harwell Institute, Harwell, UK
| | - Tertius A Hough
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council Harwell Institute, Harwell, UK
| | - Liz Bentley
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council Harwell Institute, Harwell, UK
| | - Paul T Christie
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology, and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Michelle M Simon
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council Harwell Institute, Harwell, UK
| | - Ann-Marie Mallon
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council Harwell Institute, Harwell, UK
| | - Herbert Schulz
- Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | - Roger D Cox
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council Harwell Institute, Harwell, UK
| | - Matthew A Brown
- Translational Genomics Group, Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Queensland University of Technology (QUT) at Translational Research Institute, Brisbane, Australia
| | | | - Steve D Brown
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council Harwell Institute, Harwell, UK
| | - Rajesh V Thakker
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology, and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
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Gorvin CM, Newey PJ, Rogers A, Stokes V, Neville MJ, Lines KE, Ntali G, Lees P, Morrison PJ, Singhellakis PN, Malandrinou FC, Karavitaki N, Grossman AB, Karpe F, Thakker RV. Association of prolactin receptor (PRLR) variants with prolactinomas. Hum Mol Genet 2019; 28:1023-1037. [PMID: 30445560 PMCID: PMC6400049 DOI: 10.1093/hmg/ddy396] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 10/31/2018] [Accepted: 11/11/2018] [Indexed: 02/07/2023] Open
Abstract
Prolactinomas are the most frequent type of pituitary tumors, which represent 10-20% of all intracranial neoplasms in humans. Prolactinomas develop in mice lacking the prolactin receptor (PRLR), which is a member of the cytokine receptor superfamily that signals via Janus kinase-2-signal transducer and activator of transcription-5 (JAK2-STAT5) or phosphoinositide 3-kinase-Akt (PI3K-Akt) pathways to mediate changes in transcription, differentiation and proliferation. To elucidate the role of the PRLR gene in human prolactinomas, we determined the PRLR sequence in 50 DNA samples (35 leucocytes, 15 tumors) from 46 prolactinoma patients (59% males, 41% females). This identified six germline PRLR variants, which comprised four rare variants (Gly57Ser, Glu376Gln, Arg453Trp and Asn492Ile) and two low-frequency variants (Ile76Val, Ile146Leu), but no somatic variants. The rare variants, Glu376Gln and Asn492Ile, which were in complete linkage disequilibrium, and are located in the PRLR intracellular domain, occurred with significantly higher frequencies (P < 0.0001) in prolactinoma patients than in 60 706 individuals of the Exome Aggregation Consortium cohort and 7045 individuals of the Oxford Biobank. In vitro analysis of the PRLR variants demonstrated that the Asn492Ile variant, but not Glu376Gln, when compared to wild-type (WT) PRLR, increased prolactin-induced pAkt signaling (>1.3-fold, P < 0.02) and proliferation (1.4-fold, P < 0.02), but did not affect pSTAT5 signaling. Treatment of cells with an Akt1/2 inhibitor or everolimus, which acts on the Akt pathway, reduced Asn492Ile signaling and proliferation to WT levels. Thus, our results identify an association between a gain-of-function PRLR variant and prolactinomas and reveal a new etiology and potential therapeutic approach for these neoplasms.
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Affiliation(s)
- Caroline M Gorvin
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
- Oxford NIHR Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, UK
| | - Paul J Newey
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Angela Rogers
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Victoria Stokes
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Matt J Neville
- Oxford NIHR Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, UK
- Metabolic Research Group, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Kate E Lines
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
- Oxford NIHR Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, UK
| | - Georgia Ntali
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Peter Lees
- Department of Neurosurgery, Southampton General Hospital, Southampton, Hampshire
| | - Patrick J Morrison
- Northern Ireland Regional Genetics Centre, Belfast City Hospital, Lisburn Road, Belfast, UK
| | - Panagiotis N Singhellakis
- Department of Endocrinology, Metabolism and Diabetes Mellitus, St Savvas Cancer Hospital, Athens, Greece
| | - Fotini Ch Malandrinou
- Department of Endocrinology, Metabolism and Diabetes Mellitus, St Savvas Cancer Hospital, Athens, Greece
| | - Niki Karavitaki
- Department of Endocrinology, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford, UK
| | - Ashley B Grossman
- Department of Endocrinology, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford, UK
| | - Fredrik Karpe
- Oxford NIHR Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, UK
- Metabolic Research Group, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Rajesh V Thakker
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
- Oxford NIHR Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, UK
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29
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Gorvin CM, Ahmad BN, Stechman MJ, Loh NY, Hough TA, Leo P, Marshall M, Sethi S, Bentley L, Piret SE, Reed A, Jeyabalan J, Christie PT, Wells S, Simon MM, Mallon AM, Schulz H, Huebner N, Brown MA, Cox RD, Brown SD, Thakker RV. An N-Ethyl-N-Nitrosourea (ENU)-Induced Tyr265Stop Mutation of the DNA Polymerase Accessory Subunit Gamma 2 (Polg2) Is Associated With Renal Calcification in Mice. J Bone Miner Res 2019; 34:497-507. [PMID: 30395686 PMCID: PMC6446808 DOI: 10.1002/jbmr.3624] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2018] [Revised: 10/12/2018] [Accepted: 10/28/2018] [Indexed: 12/24/2022]
Abstract
Renal calcification (RCALC) resulting in nephrolithiasis and nephrocalcinosis, which affects ∼10% of adults by 70 years of age, involves environmental and genetic etiologies. Thus, nephrolithiasis and nephrocalcinosis occurs as an inherited disorder in ∼65% of patients, and may be associated with endocrine and metabolic disorders including: primary hyperparathyroidism, hypercalciuria, renal tubular acidosis, cystinuria, and hyperoxaluria. Investigations of families with nephrolithiasis and nephrocalcinosis have identified some causative genes, but further progress is limited as large families are unavailable for genetic studies. We therefore embarked on establishing mouse models for hereditary nephrolithiasis and nephrocalcinosis by performing abdominal X-rays to identify renal opacities in N-ethyl-N-nitrosourea (ENU)-mutagenized mice. This identified a mouse with RCALC inherited as an autosomal dominant trait, designated RCALC type 2 (RCALC2). Genomewide mapping located the Rcalc2 locus to a ∼16-Mbp region on chromosome 11D-E2 and whole-exome sequence analysis identified a heterozygous mutation in the DNA polymerase gamma-2, accessory subunit (Polg2) resulting in a nonsense mutation, Tyr265Stop (Y265X), which co-segregated with RCALC2. Kidneys of mutant mice (Polg2+/Y265X ) had lower POLG2 mRNA and protein expression, compared to wild-type littermates (Polg2+/+ ). The Polg2+/Y265X and Polg2+/+ mice had similar plasma concentrations of sodium, potassium, calcium, phosphate, chloride, urea, creatinine, glucose, and alkaline phosphatase activity; and similar urinary fractional excretion of calcium, phosphate, oxalate, and protein. Polg2 encodes the minor subunit of the mitochondrial DNA (mtDNA) polymerase and the mtDNA content in Polg2+/Y265X kidneys was reduced compared to Polg2+/+ mice, and cDNA expression profiling revealed differential expression of 26 genes involved in several biological processes including mitochondrial DNA function, apoptosis, and ubiquitination, the complement pathway, and inflammatory pathways. In addition, plasma of Polg2+/Y265X mice, compared to Polg2+/+ littermates had higher levels of reactive oxygen species. Thus, our studies have identified a mutant mouse model for inherited renal calcification associated with a Polg2 nonsense mutation. © 2018 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals, Inc.
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Affiliation(s)
- Caroline M Gorvin
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Bushra N Ahmad
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Michael J Stechman
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Nellie Y Loh
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Tertius A Hough
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council, Harwell, UK
| | - Paul Leo
- Translational Genomics Group, Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Queensland University of Technology at Translational Research Institute, Brisbane, Australia
| | - Mhairi Marshall
- Translational Genomics Group, Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Queensland University of Technology at Translational Research Institute, Brisbane, Australia
| | - Siddharth Sethi
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council, Harwell, UK
| | - Liz Bentley
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council, Harwell, UK
| | - Sian E Piret
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Anita Reed
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Jeshmi Jeyabalan
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Paul T Christie
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Sara Wells
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council, Harwell, UK
| | - Michelle M Simon
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council, Harwell, UK
| | - Ann-Marie Mallon
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council, Harwell, UK
| | - Herbert Schulz
- Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | | | - Matthew A Brown
- Translational Genomics Group, Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Queensland University of Technology at Translational Research Institute, Brisbane, Australia
| | - Roger D Cox
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council, Harwell, UK
| | - Steve D Brown
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council, Harwell, UK
| | - Rajesh V Thakker
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
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Gorvin CM, Metpally R, Stokes VJ, Hannan FM, Krishnamurthy SB, Overton JD, Reid JG, Breitwieser GE, Thakker RV. Large-scale exome datasets reveal a new class of adaptor-related protein complex 2 sigma subunit (AP2σ) mutations, located at the interface with the AP2 alpha subunit, that impair calcium-sensing receptor signalling. Hum Mol Genet 2019; 27:901-911. [PMID: 29325022 PMCID: PMC5982735 DOI: 10.1093/hmg/ddy010] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 12/21/2017] [Indexed: 11/12/2022] Open
Abstract
Mutations of the sigma subunit of the heterotetrameric adaptor-related protein complex 2 (AP2σ) impair signalling of the calcium-sensing receptor (CaSR), and cause familial hypocalciuric hypercalcaemia type 3 (FHH3). To date, FHH3-associated AP2σ mutations have only been identified at one residue, Arg15. We hypothesized that additional rare AP2σ variants may also be associated with altered CaSR function and hypercalcaemia, and sought for these by analysing >111 995 exomes (>60 706 from ExAc and dbSNP, and 51 289 from the Geisinger Health System-Regeneron DiscovEHR dataset, which also contains clinical data). This identified 11 individuals to have 9 non-synonymous AP2σ variants (Arg3His, Arg15His (x3), Ala44Thr, Phe52Tyr, Arg61His, Thr112Met, Met117Ile, Glu122Gly and Glu142Lys) with 3 of the 4 individuals who had Arg15His and Met117Ile AP2σ variants having mild hypercalcaemia, thereby indicating a prevalence of FHH3-associated AP2σ mutations of ∼7.8 per 100 000 individuals. Structural modelling of the novel eight AP2σ variants (Arg3His, Ala44Thr, Phe52Tyr, Arg61His, Thr112Met, Met117Ile, Glu122Gly and Glu142Lys) predicted that the Arg3His, Thr112Met, Glu122Gly and Glu142Lys AP2σ variants would disrupt polar contacts within the AP2σ subunit or affect the interface between the AP2σ and AP2α subunits. Functional analyses of all eight AP2σ variants in CaSR-expressing cells demonstrated that the Thr112Met, Met117Ile and Glu142Lys variants, located in the AP2σ α4-α5 helical region that forms an interface with AP2α, impaired CaSR-mediated intracellular calcium (Cai2+) signalling, consistent with a loss of function, and this was rectified by treatment with the CaSR positive allosteric modulator cinacalcet. Thus, our studies demonstrate another potential class of FHH3-causing AP2σ mutations located at the AP2σ-AP2α interface.
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Affiliation(s)
- Caroline M Gorvin
- Academic Endocrine Unit, Radcliffe Department of Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), University of Oxford, Oxford OX3 7LJ, UK
| | - Raghu Metpally
- Geisinger Clinic, Weis Center for Research, Danville, PA 17822, USA
| | - Victoria J Stokes
- Academic Endocrine Unit, Radcliffe Department of Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), University of Oxford, Oxford OX3 7LJ, UK
| | - Fadil M Hannan
- Academic Endocrine Unit, Radcliffe Department of Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), University of Oxford, Oxford OX3 7LJ, UK.,Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool, L7 8TX UK
| | | | | | | | | | - Rajesh V Thakker
- Academic Endocrine Unit, Radcliffe Department of Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), University of Oxford, Oxford OX3 7LJ, UK
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Gorvin CM, Frost M, Malinauskas T, Cranston T, Boon H, Siebold C, Jones EY, Hannan FM, Thakker RV. Calcium-sensing receptor residues with loss- and gain-of-function mutations are located in regions of conformational change and cause signalling bias. Hum Mol Genet 2018; 27:3720-3733. [PMID: 30052933 PMCID: PMC6196656 DOI: 10.1093/hmg/ddy263] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 07/06/2018] [Accepted: 07/09/2018] [Indexed: 12/20/2022] Open
Abstract
The calcium-sensing receptor (CaSR) is a homodimeric G-protein-coupled receptor that signals via intracellular calcium (Ca2+i) mobilisation and phosphorylation of extracellular signal-regulated kinase 1/2 (ERK) to regulate extracellular calcium (Ca2+e) homeostasis. The central importance of the CaSR in Ca2+e homeostasis has been demonstrated by the identification of loss- or gain-of-function CaSR mutations that lead to familial hypocalciuric hypercalcaemia (FHH) or autosomal dominant hypocalcaemia (ADH), respectively. However, the mechanisms determining whether the CaSR signals via Ca2+i or ERK have not been established, and we hypothesised that some CaSR residues, which are the site of both loss- and gain-of-function mutations, may act as molecular switches to direct signalling through these pathways. An analysis of CaSR mutations identified in >300 hypercalcaemic and hypocalcaemic probands revealed five 'disease-switch' residues (Gln27, Asn178, Ser657, Ser820 and Thr828) that are affected by FHH and ADH mutations. Functional expression studies using HEK293 cells showed disease-switch residue mutations to commonly display signalling bias. For example, two FHH-associated mutations (p.Asn178Asp and p.Ser820Ala) impaired Ca2+i signalling without altering ERK phosphorylation. In contrast, an ADH-associated p.Ser657Cys mutation uncoupled signalling by leading to increased Ca2+i mobilization while decreasing ERK phosphorylation. Structural analysis of these five CaSR disease-switch residues together with four reported disease-switch residues revealed these residues to be located at conformationally active regions of the CaSR such as the extracellular dimer interface and transmembrane domain. Thus, our findings indicate that disease-switch residues are located at sites critical for CaSR activation and play a role in mediating signalling bias.
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Affiliation(s)
- Caroline M Gorvin
- Academic Endocrine Unit, Radcliffe Department of Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), University of Oxford, Oxford OX3 7LJ, UK
| | - Morten Frost
- Academic Endocrine Unit, Radcliffe Department of Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), University of Oxford, Oxford OX3 7LJ, UK
- University of Southern Denmark, Odense C, Denmark
| | - Tomas Malinauskas
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Treena Cranston
- Oxford Molecular Genetics Laboratory, Churchill Hospital, Oxford OX3 7LJ, UK
| | - Hannah Boon
- Oxford Molecular Genetics Laboratory, Churchill Hospital, Oxford OX3 7LJ, UK
| | - Christian Siebold
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - E Yvonne Jones
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Fadil M Hannan
- Academic Endocrine Unit, Radcliffe Department of Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), University of Oxford, Oxford OX3 7LJ, UK
- Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, UK
| | - Rajesh V Thakker
- Academic Endocrine Unit, Radcliffe Department of Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), University of Oxford, Oxford OX3 7LJ, UK
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Gorvin CM. Insights into calcium-sensing receptor trafficking and biased signalling by studies of calcium homeostasis. J Mol Endocrinol 2018; 61:R1-R12. [PMID: 29599414 DOI: 10.1530/jme-18-0049] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 03/29/2018] [Indexed: 12/18/2022]
Abstract
The calcium-sensing receptor (CASR) is a class C G-protein-coupled receptor (GPCR) that detects extracellular calcium concentrations, and modulates parathyroid hormone secretion and urinary calcium excretion to maintain calcium homeostasis. The CASR utilises multiple heterotrimeric G-proteins to mediate signalling effects including activation of intracellular calcium release; mitogen-activated protein kinase (MAPK) pathways; membrane ruffling; and inhibition of cAMP production. By studying germline mutations in the CASR and proteins within its signalling pathway that cause hyper- and hypocalcaemic disorders, novel mechanisms governing GPCR signalling and trafficking have been elucidated. This review focusses on two recently described pathways that provide novel insights into CASR signalling and trafficking mechanisms. The first, identified by studying a CASR gain-of-function mutation that causes autosomal dominant hypocalcaemia (ADH), demonstrated a structural motif located between the third transmembrane domain and the second extracellular loop of the CASR that mediates biased signalling by activating a novel β-arrestin-mediated G-protein-independent pathway. The second, in which the mechanism by which adaptor protein-2 σ-subunit (AP2σ) mutations cause familial hypocalciuric hypercalcaemia (FHH) was investigated, demonstrated that AP2σ mutations impair CASR internalisation and reduce multiple CASR-mediated signalling pathways. Furthermore, these studies showed that the CASR can signal from the cell surface using multiple G-protein pathways, whilst sustained signalling is mediated only by the Gq/11 pathway. Thus, studies of FHH- and ADH-associated mutations have revealed novel steps by which CASR mediates signalling and compartmental bias, and these pathways could provide new targets for therapies for patients with calcaemic disorders.
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Affiliation(s)
- Caroline M Gorvin
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, Birmingham, UK
- Centre for Endocrinology, Diabetes and Metabolism (CEDAM), Birmingham Health Partners, Birmingham, UK
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Patel J, Chuaiphichai S, Douglas G, Gorvin CM, Channon KM. Vascular wall regulator of G-protein signalling-1 (RGS-1) is required for angiotensin II-mediated blood pressure control. Vascul Pharmacol 2018; 108:15-22. [PMID: 29654907 PMCID: PMC6073721 DOI: 10.1016/j.vph.2018.04.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 03/18/2018] [Accepted: 04/05/2018] [Indexed: 02/07/2023]
Abstract
G-Protein coupled receptors (GPCRs) activate intracellular signalling pathways by coupling to heterotrimeric G-proteins that control many physiological processes including blood pressure homeostasis. The Regulator of G-Protein Signalling-1 (RGS1) controls the magnitude and duration of downstream GPCR signalling by acting as a GTPase-activating protein for specific Gα-proteins. RGS1 has contrasting roles in haematopoietic and non-haematopoietic cells. Rgs1−/−ApoE−/− mice are protected from Angiotensin II (Ang II)-induced aortic aneurysm rupture. Conversely, Ang II treatment increases systolic blood pressure to a greater extent in Rgs1−/−ApoE−/− mice than ApoE−/− mice, independent of its role in myeloid cells. However the precise role of RGS1 in hypertension and vascular-derived cells remains unknown. We determined the effects of Rgs1 deletion on vascular function in ApoE−/− mice. Rgs1 deletion led to enhanced vasoconstriction in aortas and mesenteric arteries from ApoE−/− mice in response to phenylephrine (PE) and U46619 respectively. Rgs1 was shown to have a role in the vasculature, with endothelium-dependent vasodilation being impaired, and endothelium-independent dilatation to SNP being enhanced in Rgs1−/−ApoE−/− mesenteric arteries. To address the downstream signalling pathways in vascular smooth muscle cells (VSMCs) in response to Ang II-stimulation, we assessed pErk1/2, pJNK and pp38 MAPK activation in VSMCs transiently transfected with Rgs1. pErk1/2 signalling but not pJNK and pp38 signalling was impaired in the presence of Rgs1. Furthermore, we demonstrated that the enhanced contractile response to PE in Rgs1−/−ApoE−/− aortas was reduced by a MAPK/Erk (MEK) inhibitor and an L-type voltage gated calcium channel antagonist, suggesting that Erk1/2 signalling and calcium influx are major effectors of Rgs1-mediated vascular contractile responses, respectively. These findings indicate RGS1 is a novel regulator of blood pressure homeostasis and highlight RGS1-controlled signalling pathways in the vasculature that may be new drug development targets for hypertension.
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MESH Headings
- Angiotensin II
- Animals
- Aorta, Thoracic/metabolism
- Aorta, Thoracic/physiopathology
- Blood Pressure/genetics
- Calcium Signaling
- Cell Line
- Disease Models, Animal
- Hypertension/chemically induced
- Hypertension/genetics
- Hypertension/metabolism
- Hypertension/physiopathology
- Male
- Mesenteric Arteries/metabolism
- Mesenteric Arteries/physiopathology
- Mice, Knockout, ApoE
- Mitogen-Activated Protein Kinase 1/metabolism
- Mitogen-Activated Protein Kinase 3/metabolism
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/physiopathology
- Phosphorylation
- RGS Proteins/deficiency
- RGS Proteins/genetics
- RGS Proteins/metabolism
- Receptor, Angiotensin, Type 1/metabolism
- Vasoconstriction
- Vasodilation
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Affiliation(s)
- Jyoti Patel
- Division of Cardiovascular Medicine, British Heart Foundation Centre of Research Excellence, Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford, Oxford, OX3 9DU, UK; Wellcome Centre for Human Genetics, University of Oxford, Oxford, OX3 7BN, UK.
| | - Surawee Chuaiphichai
- Division of Cardiovascular Medicine, British Heart Foundation Centre of Research Excellence, Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford, Oxford, OX3 9DU, UK; Wellcome Centre for Human Genetics, University of Oxford, Oxford, OX3 7BN, UK
| | - Gillian Douglas
- Division of Cardiovascular Medicine, British Heart Foundation Centre of Research Excellence, Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford, Oxford, OX3 9DU, UK; Wellcome Centre for Human Genetics, University of Oxford, Oxford, OX3 7BN, UK
| | - Caroline M Gorvin
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology, and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 7LE, UK
| | - Keith M Channon
- Division of Cardiovascular Medicine, British Heart Foundation Centre of Research Excellence, Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford, Oxford, OX3 9DU, UK; Wellcome Centre for Human Genetics, University of Oxford, Oxford, OX3 7BN, UK
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Gorvin CM, Babinsky VN, Malinauskas T, Nissen PH, Schou AJ, Hanyaloglu AC, Siebold C, Jones EY, Hannan FM, Thakker RV. A calcium-sensing receptor mutation causing hypocalcemia disrupts a transmembrane salt bridge to activate β-arrestin-biased signaling. Sci Signal 2018; 11:eaan3714. [PMID: 29463778 PMCID: PMC6166785 DOI: 10.1126/scisignal.aan3714] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The calcium-sensing receptor (CaSR) is a G protein-coupled receptor (GPCR) that signals through Gq/11 and Gi/o to stimulate cytosolic calcium (Ca2+i) and mitogen-activated protein kinase (MAPK) signaling to control extracellular calcium homeostasis. Studies of loss- and gain-of-function CASR mutations, which cause familial hypocalciuric hypercalcemia type 1 (FHH1) and autosomal dominant hypocalcemia type 1 (ADH1), respectively, have revealed that the CaSR signals in a biased manner. Thus, some mutations associated with FHH1 lead to signaling predominantly through the MAPK pathway, whereas mutations associated with ADH1 preferentially enhance Ca2+i responses. We report a previously unidentified ADH1-associated R680G CaSR mutation, which led to the identification of a CaSR structural motif that mediates biased signaling. Expressing CaSRR680G in HEK 293 cells showed that this mutation increased MAPK signaling without altering Ca2+i responses. Moreover, this gain of function in MAPK activity occurred independently of Gq/11 and Gi/o and was mediated instead by a noncanonical pathway involving β-arrestin proteins. Homology modeling and mutagenesis studies showed that the R680G CaSR mutation selectively enhanced β-arrestin signaling by disrupting a salt bridge formed between Arg680 and Glu767, which are located in CaSR transmembrane domain 3 and extracellular loop 2, respectively. Thus, our results demonstrate CaSR signaling through β-arrestin and the importance of the Arg680-Glu767 salt bridge in mediating signaling bias.
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Affiliation(s)
- Caroline M Gorvin
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 7LJ, UK
| | - Valerie N Babinsky
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 7LJ, UK
| | - Tomas Malinauskas
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Peter H Nissen
- Department of Clinical Biochemistry, Aarhus University Hospital, DK-8200 Aarhus N, Denmark
| | - Anders J Schou
- Hans Christian Andersen Children's Hospital, Odense University Hospital, 5000 Odense C, Denmark
| | - Aylin C Hanyaloglu
- Institute of Reproductive and Developmental Biology, Faculty of Medicine, Imperial College London W12 0NN, UK
| | - Christian Siebold
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - E Yvonne Jones
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Fadil M Hannan
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 7LJ, UK.
- Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool L7 8TX, UK
| | - Rajesh V Thakker
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 7LJ, UK.
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Gorvin CM, Rogers A, Hastoy B, Tarasov AI, Frost M, Sposini S, Inoue A, Whyte MP, Rorsman P, Hanyaloglu AC, Breitwieser GE, Thakker RV. AP2σ Mutations Impair Calcium-Sensing Receptor Trafficking and Signaling, and Show an Endosomal Pathway to Spatially Direct G-Protein Selectivity. Cell Rep 2018; 22:1054-1066. [PMID: 29420171 PMCID: PMC5792449 DOI: 10.1016/j.celrep.2017.12.089] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 11/30/2017] [Accepted: 12/22/2017] [Indexed: 12/29/2022] Open
Abstract
Spatial control of G-protein-coupled receptor (GPCR) signaling, which is used by cells to translate complex information into distinct downstream responses, is achieved by using plasma membrane (PM) and endocytic-derived signaling pathways. The roles of the endomembrane in regulating such pleiotropic signaling via multiple G-protein pathways remain unknown. Here, we investigated the effects of disease-causing mutations of the adaptor protein-2 σ subunit (AP2σ) on signaling by the class C GPCR calcium-sensing receptor (CaSR). These AP2σ mutations increase CaSR PM expression yet paradoxically reduce CaSR signaling. Hypercalcemia-associated AP2σ mutations reduced CaSR signaling via Gαq/11 and Gαi/o pathways. The mutations also delayed CaSR internalization due to prolonged residency time of CaSR in clathrin structures that impaired or abolished endosomal signaling, which was predominantly mediated by Gαq/11. Thus, compartmental bias for CaSR-mediated Gαq/11 endomembrane signaling provides a mechanistic basis for multidimensional GPCR signaling. Disease-causing AP2σ mutants impair Gαq/11 and Gαi/o signaling by CaSR, a class C GPCR AP2σ mutants impair trafficking of the CaSR The CaSR can signal by a sustained endosomal pathway CaSR differentially uses Gαq/11 and Gαi/o for cell-surface and endosomal signaling
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Affiliation(s)
- Caroline M Gorvin
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, UK; Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, UK; Centre for Endocrinology, Diabetes and Metabolism (CEDAM), Birmingham Health Partners, Birmingham, UK
| | - Angela Rogers
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Benoit Hastoy
- Diabetes Research Laboratory, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Andrei I Tarasov
- Diabetes Research Laboratory, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Morten Frost
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Silvia Sposini
- Institute of Reproductive and Developmental Biology, Faculty of Medicine, Imperial College London, London, UK
| | - Asuka Inoue
- Laboratory of Molecular and Cellular Biochemistry, Tohoku University, Sendai, Japan; Japan Science and Technology (JST) Agency, Precursory Research for Embryonic Science and Technology (PRESTO), Kawaguchi, Japan
| | - Michael P Whyte
- Center for Metabolic Bone Disease and Molecular Research, Shriners Hospitals for Children, St. Louis, MO, USA
| | - Patrik Rorsman
- Diabetes Research Laboratory, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Aylin C Hanyaloglu
- Institute of Reproductive and Developmental Biology, Faculty of Medicine, Imperial College London, London, UK
| | - Gerda E Breitwieser
- Geisinger Clinic, Weis Center for Research, Department of Functional and Molecular Genomics, Danville, PA, USA
| | - Rajesh V Thakker
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.
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Gorvin CM, Hannan FM, Cranston T, Valta H, Makitie O, Schalin-Jantti C, Thakker RV. Cinacalcet Rectifies Hypercalcemia in a Patient With Familial Hypocalciuric Hypercalcemia Type 2 (FHH2) Caused by a Germline Loss-of-Function Gα 11 Mutation. J Bone Miner Res 2018; 33:32-41. [PMID: 28833550 PMCID: PMC5813271 DOI: 10.1002/jbmr.3241] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 08/09/2017] [Accepted: 08/14/2017] [Indexed: 12/15/2022]
Abstract
G-protein subunit α-11 (Gα11 ) couples the calcium-sensing receptor (CaSR) to phospholipase C (PLC)-mediated intracellular calcium (Ca2+i ) and mitogen-activated protein kinase (MAPK) signaling, which in the parathyroid glands and kidneys regulates parathyroid hormone release and urinary calcium excretion, respectively. Heterozygous germline loss-of-function Gα11 mutations cause familial hypocalciuric hypercalcemia type 2 (FHH2), for which effective therapies are currently not available. Here, we report a novel heterozygous Gα11 germline mutation, Phe220Ser, which was associated with hypercalcemia in a family with FHH2. Homology modeling showed the wild-type (WT) Phe220 nonpolar residue to form part of a cluster of hydrophobic residues within a highly conserved cleft region of Gα11 , which binds to and activates PLC; and predicted that substitution of Phe220 with the mutant Ser220 polar hydrophilic residue would disrupt PLC-mediated signaling. In vitro studies involving transient transfection of WT and mutant Gα11 proteins into HEK293 cells, which express the CaSR, showed the mutant Ser220 Gα11 protein to impair CaSR-mediated Ca2+i and extracellular signal-regulated kinase 1/2 (ERK) MAPK signaling, consistent with diminished activation of PLC. Furthermore, engineered mutagenesis studies demonstrated that loss of hydrophobicity within the Gα11 cleft region also impaired signaling by PLC. The loss-of-function associated with the Ser220 Gα11 mutant was rectified by treatment of cells with cinacalcet, which is a CaSR-positive allosteric modulator. Furthermore, in vivo administration of cinacalcet to the proband harboring the Phe220Ser Gα11 mutation, normalized serum ionized calcium concentrations. Thus, our studies, which report a novel Gα11 germline mutation (Phe220Ser) in a family with FHH2, reveal the importance of the Gα11 hydrophobic cleft region for CaSR-mediated activation of PLC, and show that allosteric CaSR modulation can rectify the loss-of-function Phe220Ser mutation and ameliorate the hypercalcemia associated with FHH2. © 2017 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals Inc.
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Affiliation(s)
- Caroline M Gorvin
- Academic Endocrine Unit, Radcliffe Department of Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), University of Oxford, UK
| | - Fadil M Hannan
- Academic Endocrine Unit, Radcliffe Department of Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), University of Oxford, UK.,Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool, UK
| | - Treena Cranston
- Oxford Molecular Genetics Laboratory, Churchill Hospital, Oxford, UK
| | - Helena Valta
- Children's Hospital, University of Helsinki, Helsinki, Finland
| | - Outi Makitie
- Children's Hospital, University of Helsinki, Helsinki, Finland.,Folkhälsan Research Center, Helsinki, Finland
| | - Camilla Schalin-Jantti
- Division of Endocrinology, Abdominal Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Rajesh V Thakker
- Academic Endocrine Unit, Radcliffe Department of Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), University of Oxford, UK
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Howles SA, Hannan FM, Gorvin CM, Piret SE, Paudyal A, Stewart M, Hough TA, Nesbit MA, Wells S, Brown SD, Cox RD, Thakker RV. Cinacalcet corrects hypercalcemia in mice with an inactivating Gα11 mutation. JCI Insight 2017; 2:96540. [PMID: 29046478 PMCID: PMC5846897 DOI: 10.1172/jci.insight.96540] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 09/19/2017] [Indexed: 11/17/2022] Open
Abstract
Loss-of-function mutations of GNA11, which encodes G-protein subunit α11 (Gα11), a signaling partner for the calcium-sensing receptor (CaSR), result in familial hypocalciuric hypercalcemia type 2 (FHH2). FHH2 is characterized by hypercalcemia, inappropriately normal or raised parathyroid hormone (PTH) concentrations, and normal or low urinary calcium excretion. A mouse model for FHH2 that would facilitate investigations of the in vivo role of Gα11 and the evaluation of calcimimetic drugs, which are CaSR allosteric activators, is not available. We therefore screened DNA from > 10,000 mice treated with the chemical mutagen N-ethyl-N-nitrosourea (ENU) for GNA11 mutations and identified a Gα11 variant, Asp195Gly (D195G), which downregulated CaSR-mediated intracellular calcium signaling in vitro, consistent with it being a loss-of-function mutation. Treatment with the calcimimetic cinacalcet rectified these signaling responses. In vivo studies showed mutant heterozygous (Gna11+/195G) and homozygous (Gna11195G/195G) mice to be hypercalcemic with normal or increased plasma PTH concentrations and normal urinary calcium excretion. Cinacalcet (30mg/kg orally) significantly reduced plasma albumin–adjusted calcium and PTH concentrations in Gna11+/195G and Gna11195G/195G mice. Thus, our studies have established a mouse model with a germline loss-of-function Gα11 mutation that is representative for FHH2 in humans and demonstrated that cinacalcet can correct the associated abnormalities of plasma calcium and PTH. Cinacalcet corrects hypercalcemia in a mouse model for familial hypocalciuric hypercalcemia type 2 (FHH2) caused by a germline loss-of-function G-protein subunit α11 (Gα11) mutation, Asp195Gly.
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Affiliation(s)
- Sarah A Howles
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Fadil M Hannan
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom.,Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom
| | - Caroline M Gorvin
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Sian E Piret
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Anju Paudyal
- Mammalian Genetics Unit and Mary Lyon Centre, Medical Research Council (MRC) Harwell Institute, Harwell Science and Innovation Campus, United Kingdom
| | - Michelle Stewart
- Mammalian Genetics Unit and Mary Lyon Centre, Medical Research Council (MRC) Harwell Institute, Harwell Science and Innovation Campus, United Kingdom
| | - Tertius A Hough
- Mammalian Genetics Unit and Mary Lyon Centre, Medical Research Council (MRC) Harwell Institute, Harwell Science and Innovation Campus, United Kingdom
| | - M Andrew Nesbit
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom.,Biomedical Sciences Research Institute, Ulster University, Coleraine, United Kingdom
| | - Sara Wells
- Mammalian Genetics Unit and Mary Lyon Centre, Medical Research Council (MRC) Harwell Institute, Harwell Science and Innovation Campus, United Kingdom
| | - Stephen Dm Brown
- Mammalian Genetics Unit and Mary Lyon Centre, Medical Research Council (MRC) Harwell Institute, Harwell Science and Innovation Campus, United Kingdom
| | - Roger D Cox
- Mammalian Genetics Unit and Mary Lyon Centre, Medical Research Council (MRC) Harwell Institute, Harwell Science and Innovation Campus, United Kingdom
| | - Rajesh V Thakker
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
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Babinsky VN, Hannan FM, Ramracheya RD, Zhang Q, Nesbit MA, Hugill A, Bentley L, Hough TA, Joynson E, Stewart M, Aggarwal A, Prinz-Wohlgenannt M, Gorvin CM, Kallay E, Wells S, Cox RD, Richards D, Rorsman P, Thakker RV. Mutant Mice With Calcium-Sensing Receptor Activation Have Hyperglycemia That Is Rectified by Calcilytic Therapy. Endocrinology 2017; 158:2486-2502. [PMID: 28575322 PMCID: PMC5551547 DOI: 10.1210/en.2017-00111] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Accepted: 05/30/2017] [Indexed: 12/12/2022]
Abstract
The calcium-sensing receptor (CaSR) is a family C G-protein-coupled receptor that plays a pivotal role in extracellular calcium homeostasis. The CaSR is also highly expressed in pancreatic islet α- and β-cells that secrete glucagon and insulin, respectively. To determine whether the CaSR may influence systemic glucose homeostasis, we characterized a mouse model with a germline gain-of-function CaSR mutation, Leu723Gln, referred to as Nuclear flecks (Nuf). Heterozygous- (CasrNuf/+) and homozygous-affected (CasrNuf/Nuf) mice were shown to have hypocalcemia in association with impaired glucose tolerance and insulin secretion. Oral administration of a CaSR antagonist compound, known as a calcilytic, rectified the glucose intolerance and hypoinsulinemia of CasrNuf/+ mice and ameliorated glucose intolerance in CasrNuf/Nuf mice. Ex vivo studies showed CasrNuf/+ and CasrNuf/Nuf mice to have reduced pancreatic islet mass and β-cell proliferation. Electrophysiological analysis of isolated CasrNuf/Nuf islets showed CaSR activation to increase the basal electrical activity of β-cells independently of effects on the activity of the adenosine triphosphate (ATP)-sensitive K+ (KATP) channel. CasrNuf/Nuf mice also had impaired glucose-mediated suppression of glucagon secretion, which was associated with increased numbers of α-cells and a higher α-cell proliferation rate. Moreover, CasrNuf/Nuf islet electrophysiology demonstrated an impairment of α-cell membrane depolarization in association with attenuated α-cell basal KATP channel activity. These studies indicate that the CaSR activation impairs glucose tolerance by a combination of α- and β-cell defects and also influences pancreatic islet mass. Moreover, our findings highlight a potential application of targeted CaSR compounds for modulating glucose metabolism.
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Affiliation(s)
- Valerie N. Babinsky
- Radcliffe Department of Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford OX3 7LE, United Kingdom
| | - Fadil M. Hannan
- Radcliffe Department of Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford OX3 7LE, United Kingdom
- Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool L7 8TX, United Kingdom
| | - Reshma D. Ramracheya
- Radcliffe Department of Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford OX3 7LE, United Kingdom
| | - Quan Zhang
- Radcliffe Department of Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford OX3 7LE, United Kingdom
| | - M. Andrew Nesbit
- Radcliffe Department of Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford OX3 7LE, United Kingdom
- Biomedical Sciences Research Institute, Ulster University, Coleraine BT52 1SA, United Kingdom
| | - Alison Hugill
- Medical Research Council Mammalian Genetics Unit and Mary Lyon Centre, Medical Research Council Harwell Institute, Harwell Science and Innovation Campus, Oxfordshire OX11 0RD, United Kingdom
| | - Liz Bentley
- Medical Research Council Mammalian Genetics Unit and Mary Lyon Centre, Medical Research Council Harwell Institute, Harwell Science and Innovation Campus, Oxfordshire OX11 0RD, United Kingdom
| | - Tertius A. Hough
- Medical Research Council Mammalian Genetics Unit and Mary Lyon Centre, Medical Research Council Harwell Institute, Harwell Science and Innovation Campus, Oxfordshire OX11 0RD, United Kingdom
| | - Elizabeth Joynson
- Medical Research Council Mammalian Genetics Unit and Mary Lyon Centre, Medical Research Council Harwell Institute, Harwell Science and Innovation Campus, Oxfordshire OX11 0RD, United Kingdom
| | - Michelle Stewart
- Medical Research Council Mammalian Genetics Unit and Mary Lyon Centre, Medical Research Council Harwell Institute, Harwell Science and Innovation Campus, Oxfordshire OX11 0RD, United Kingdom
| | - Abhishek Aggarwal
- Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna A-1090, Austria
| | | | - Caroline M. Gorvin
- Radcliffe Department of Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford OX3 7LE, United Kingdom
| | - Enikö Kallay
- Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna A-1090, Austria
| | - Sara Wells
- Medical Research Council Mammalian Genetics Unit and Mary Lyon Centre, Medical Research Council Harwell Institute, Harwell Science and Innovation Campus, Oxfordshire OX11 0RD, United Kingdom
| | - Roger D. Cox
- Medical Research Council Mammalian Genetics Unit and Mary Lyon Centre, Medical Research Council Harwell Institute, Harwell Science and Innovation Campus, Oxfordshire OX11 0RD, United Kingdom
| | - Duncan Richards
- GlaxoSmithKline Clinical Unit, Cambridge CB2 0GG, United Kingdom
| | - Patrik Rorsman
- Radcliffe Department of Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford OX3 7LE, United Kingdom
| | - Rajesh V. Thakker
- Radcliffe Department of Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford OX3 7LE, United Kingdom
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Gorvin CM, Rogers A, Stewart M, Paudyal A, Hough TA, Teboul L, Wells S, Brown SD, Cox RD, Thakker RV. N-ethyl-N-nitrosourea-Induced Adaptor Protein 2 Sigma Subunit 1 ( Ap2s1) Mutations Establish Ap2s1 Loss-of-Function Mice. JBMR Plus 2017; 1:3-15. [PMID: 29479578 PMCID: PMC5824975 DOI: 10.1002/jbm4.10001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The adaptor protein‐2 sigma subunit (AP2σ), encoded by AP2S1, forms a heterotetrameric complex, with AP2α, AP2β, and AP2μ subunits, that is pivotal for clathrin‐mediated endocytosis, and AP2σ loss‐of‐function mutations impair internalization of the calcium‐sensing receptor (CaSR), a G‐protein–coupled receptor, and cause familial hypocalciuric hypercalcemia type‐3 (FHH3). Mice with AP2σ mutations that would facilitate investigations of the in vivo role of AP2σ, are not available, and we therefore embarked on establishing such mice. We screened >10,000 mice treated with the mutagen N‐ethyl‐N‐nitrosourea (ENU) for Ap2s1 mutations and identified 5 Ap2s1 variants, comprising 2 missense (Tyr20Asn and Ile123Asn) and 3 intronic base substitutions, one of which altered the invariant donor splice site dinucleotide gt to gc. Three‐dimensional modeling and cellular expression of the missense Ap2s1 variants did not reveal them to alter AP2σ structure or CaSR‐mediated signaling, but investigation of the donor splice site variant revealed it to result in an in‐frame deletion of 17 evolutionarily conserved amino acids (del17) that formed part of the AP2σ α1‐helix, α1‐β3 loop, and β3 strand. Heterozygous mutant mice (Ap2s1+/del17) were therefore established, and these had AP2σ haplosufficiency but were viable with normal appearance and growth. Ap2s1+/del17 mice, when compared with Ap2s1+/+ mice, also had normal plasma concentrations of calcium, phosphate, magnesium, creatinine, urea, sodium, potassium, and alkaline phosphatase activity; normal urinary fractional excretion of calcium, phosphate, sodium, and potassium; and normal plasma parathyroid hormone (PTH) and 1,25‐dihydroxyvitamin D (1,25(OH)2) concentrations. However, homozygous Ap2s1del17/del17 mice were non‐viable and died between embryonic days 3.5 and 9.5 (E3.5–9.5), thereby indicating that AP2σ likely has important roles at the embryonic patterning stages and organogenesis of the heart, thyroid, liver, gut, lungs, pancreas, and neural systems. Thus, our studies have established a mutant mouse model that is haplosufficient for AP2σ. © 2017 The Authors. JBMR Plus is published by Wiley Periodicals, Inc. on behalf of the American Society for Bone and Mineral Research.
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Affiliation(s)
- Caroline M Gorvin
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford Centre for Diabetes, Endocrinology, and Metabolism (OCDEM), Churchill Hospital, Oxford, UK
| | - Angela Rogers
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford Centre for Diabetes, Endocrinology, and Metabolism (OCDEM), Churchill Hospital, Oxford, UK
| | - Michelle Stewart
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council Harwell Institute, Harwell Campus, Oxfordshire, UK
| | - Anju Paudyal
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council Harwell Institute, Harwell Campus, Oxfordshire, UK
| | - Tertius A Hough
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council Harwell Institute, Harwell Campus, Oxfordshire, UK
| | - Lydia Teboul
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council Harwell Institute, Harwell Campus, Oxfordshire, UK
| | - Sara Wells
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council Harwell Institute, Harwell Campus, Oxfordshire, UK
| | - Steve Dm Brown
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council Harwell Institute, Harwell Campus, Oxfordshire, UK
| | - Roger D Cox
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council Harwell Institute, Harwell Campus, Oxfordshire, UK
| | - Rajesh V Thakker
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford Centre for Diabetes, Endocrinology, and Metabolism (OCDEM), Churchill Hospital, Oxford, UK
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Gorvin CM, Hannan FM, Howles SA, Babinsky VN, Piret SE, Rogers A, Freidin AJ, Stewart M, Paudyal A, Hough TA, Nesbit MA, Wells S, Vincent TL, Brown SD, Cox RD, Thakker RV. G α11 mutation in mice causes hypocalcemia rectifiable by calcilytic therapy. JCI Insight 2017; 2:e91103. [PMID: 28194447 PMCID: PMC5291742 DOI: 10.1172/jci.insight.91103] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Accepted: 01/03/2017] [Indexed: 12/11/2022] Open
Abstract
Heterozygous germline gain-of-function mutations of G-protein subunit α11 (Gα11), a signaling partner for the calcium-sensing receptor (CaSR), result in autosomal dominant hypocalcemia type 2 (ADH2). ADH2 may cause symptomatic hypocalcemia with low circulating parathyroid hormone (PTH) concentrations. Effective therapies for ADH2 are currently not available, and a mouse model for ADH2 would help in assessment of potential therapies. We hypothesized that a previously reported dark skin mouse mutant (Dsk7) - which has a germline hypermorphic Gα11 mutation, Ile62Val - may be a model for ADH2 and allow evaluation of calcilytics, which are CaSR negative allosteric modulators, as a targeted therapy for this disorder. Mutant Dsk7/+ and Dsk7/Dsk7 mice were shown to have hypocalcemia and reduced plasma PTH concentrations, similar to ADH2 patients. In vitro studies showed the mutant Val62 Gα11 to upregulate CaSR-mediated intracellular calcium and MAPK signaling, consistent with a gain of function. Treatment with NPS-2143, a calcilytic compound, normalized these signaling responses. In vivo, NPS-2143 induced a rapid and marked rise in plasma PTH and calcium concentrations in Dsk7/Dsk7 and Dsk7/+ mice, which became normocalcemic. Thus, these studies have established Dsk7 mice, which harbor a germline gain-of-function Gα11 mutation, as a model for ADH2 and have demonstrated calcilytics as a potential targeted therapy.
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Affiliation(s)
- Caroline M. Gorvin
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Fadil M. Hannan
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
- Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom
| | - Sarah A. Howles
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Valerie N. Babinsky
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Sian E. Piret
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Angela Rogers
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Andrew J. Freidin
- ARUK Centre for Osteoarthritis Pathogenesis, The Kennedy Institute of Rheumatology, University of Oxford, Oxford, United Kingdom
| | - Michelle Stewart
- Medical Research Council (MRC) Mammalian Genetics Unit and Mary Lyon Centre, MRC Harwell Institute, Harwell Science and Innovation Campus, United Kingdom
| | - Anju Paudyal
- Medical Research Council (MRC) Mammalian Genetics Unit and Mary Lyon Centre, MRC Harwell Institute, Harwell Science and Innovation Campus, United Kingdom
| | - Tertius A. Hough
- Medical Research Council (MRC) Mammalian Genetics Unit and Mary Lyon Centre, MRC Harwell Institute, Harwell Science and Innovation Campus, United Kingdom
| | - M. Andrew Nesbit
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
- Biomedical Sciences Research Institute, Ulster University, Coleraine, United Kingdom
| | - Sara Wells
- Medical Research Council (MRC) Mammalian Genetics Unit and Mary Lyon Centre, MRC Harwell Institute, Harwell Science and Innovation Campus, United Kingdom
| | - Tonia L. Vincent
- ARUK Centre for Osteoarthritis Pathogenesis, The Kennedy Institute of Rheumatology, University of Oxford, Oxford, United Kingdom
| | - Stephen D.M. Brown
- Medical Research Council (MRC) Mammalian Genetics Unit and Mary Lyon Centre, MRC Harwell Institute, Harwell Science and Innovation Campus, United Kingdom
| | - Roger D. Cox
- Medical Research Council (MRC) Mammalian Genetics Unit and Mary Lyon Centre, MRC Harwell Institute, Harwell Science and Innovation Campus, United Kingdom
| | - Rajesh V. Thakker
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
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Roszko KL, Bi R, Gorvin CM, Bräuner-Osborne H, Xiong XF, Inoue A, Thakker RV, Strømgaard K, Gardella T, Mannstadt M. Knockin mouse with mutant G α11 mimics human inherited hypocalcemia and is rescued by pharmacologic inhibitors. JCI Insight 2017; 2:e91079. [PMID: 28194446 PMCID: PMC5291736 DOI: 10.1172/jci.insight.91079] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Heterotrimeric G proteins play critical roles in transducing extracellular signals generated by 7-transmembrane domain receptors. Somatic gain-of-function mutations in G protein α subunits are associated with a variety of diseases. Recently, we identified gain-of-function mutations in Gα11 in patients with autosomal-dominant hypocalcemia type 2 (ADH2), an inherited disorder of hypocalcemia, low parathyroid hormone (PTH), and hyperphosphatemia. We have generated knockin mice harboring the point mutation GNA11 c.C178T (p.Arg60Cys) identified in ADH2 patients. The mutant mice faithfully replicated human ADH2. They also exhibited low bone mineral density and increased skin pigmentation. Treatment with NPS 2143, a negative allosteric modulator of the calcium-sensing receptor (CASR), increased PTH and calcium concentrations in WT and mutant mice, suggesting that the gain-of-function effect of GNA11R6OC is partly dependent on coupling to the CASR. Treatment with the Gα11/q-specific inhibitor YM-254890 increased blood calcium in heterozygous but not in homozygous GNA11R60C mice, consistent with published crystal structure data showing that Arg60 forms a critical contact with YM-254890. This animal model of ADH2 provides insights into molecular mechanism of this G protein-related disease and potential paths toward new lines of therapy.
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Affiliation(s)
- Kelly L Roszko
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Ruiye Bi
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
- West China School of Stomatology, Sichuan University, Chengdu, Sichuan, China
| | - Caroline M Gorvin
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Churchill Hospital, Oxford, England, United Kingdom
| | - Hans Bräuner-Osborne
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Xiao-Feng Xiong
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Asuka Inoue
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
- Japan Science and Technology Agency (JST), Precursory Research for Embryonic Science and Technology (PRESTO), Kawaguchi, Saitama, Japan
| | - Rajesh V Thakker
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Churchill Hospital, Oxford, England, United Kingdom
| | - Kristian Strømgaard
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Thomas Gardella
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Michael Mannstadt
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
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Piret SE, Gorvin CM, Trinh A, Taylor J, Lise S, Taylor JC, Ebeling PR, Thakker RV. Autosomal dominant osteopetrosis associated with renal tubular acidosis is due to a CLCN7 mutation. Am J Med Genet A 2016; 170:2988-2992. [PMID: 27540713 PMCID: PMC5132132 DOI: 10.1002/ajmg.a.37755] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Accepted: 04/21/2016] [Indexed: 12/16/2022]
Abstract
The aim of this study was to identify the causative mutation in a family with an unusual presentation of autosomal dominant osteopetrosis (OPT), proximal renal tubular acidosis (RTA), renal stones, epilepsy, and blindness, a combination of features not previously reported. We undertook exome sequencing of one affected and one unaffected family member, followed by targeted analysis of known candidate genes to identify the causative mutation. This identified a missense mutation (c.643G>A; p.Gly215Arg) in the gene encoding the chloride/proton antiporter 7 (gene CLCN7, protein CLC‐7), which was confirmed by amplification refractory mutation system (ARMS)‐PCR, and to be present in the three available patients. CLC‐7 mutations are known to cause autosomal dominant OPT type 2, also called Albers–Schonberg disease, which is characterized by osteosclerosis, predominantly of the spine, pelvis and skull base, resulting in bone fragility and fractures. Albers–Schonberg disease is not reported to be associated with RTA, but autosomal recessive OPT type 3 (OPTB3) with RTA is associated with carbonic anhydrase type 2 (CA2) mutations. No mutations were detected in CA2 or any other genes known to cause proximal RTA. Neither CLCN7 nor CA2 mutations have previously been reported to be associated with renal stones or epilepsy. Thus, we identified a CLCN7 mutation in a family with autosomal dominant osteopetrosis, RTA, renal stones, epilepsy, and blindness. © 2016 The Authors. American Journal of Medical Genetics Part A Published by Wiley Periodicals, Inc.
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Affiliation(s)
- Sian E Piret
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, University of Oxford, Oxford, United Kingdom
| | - Caroline M Gorvin
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, University of Oxford, Oxford, United Kingdom
| | - Anne Trinh
- Faculty of Medicine, Nursing and Health Sciences, Department of Medicine, School of Clinical Sciences, Monash Medical Centre, Monash University, Clayton, Victoria, Australia
| | - John Taylor
- Oxford Medical Genetics Laboratories, Churchill Hospital, Oxford University Hospitals NHS Trust, Oxford, United Kingdom
| | - Stefano Lise
- Wellcome Trust Centre for Human Genetics, Oxford, United Kingdom
- Oxford NIHR Comprehensive Biomedical Research Centre, Oxford, United Kingdom
| | - Jenny C Taylor
- Wellcome Trust Centre for Human Genetics, Oxford, United Kingdom
- Oxford NIHR Comprehensive Biomedical Research Centre, Oxford, United Kingdom
| | - Peter R Ebeling
- Faculty of Medicine, Nursing and Health Sciences, Department of Medicine, School of Clinical Sciences, Monash Medical Centre, Monash University, Clayton, Victoria, Australia
| | - Rajesh V Thakker
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, University of Oxford, Oxford, United Kingdom.
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Piret SE, Gorvin CM, Pagnamenta AT, Howles SA, Cranston T, Rust N, Nesbit MA, Glaser B, Taylor JC, Buchs AE, Hannan FM, Thakker RV. Identification of a G-Protein Subunit-α11 Gain-of-Function Mutation, Val340Met, in a Family With Autosomal Dominant Hypocalcemia Type 2 (ADH2). J Bone Miner Res 2016; 31:1207-14. [PMID: 26818911 PMCID: PMC4915495 DOI: 10.1002/jbmr.2797] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 01/18/2016] [Accepted: 01/22/2016] [Indexed: 01/24/2023]
Abstract
Autosomal dominant hypocalcemia (ADH) is characterized by hypocalcemia, inappropriately low serum parathyroid hormone concentrations and hypercalciuria. ADH is genetically heterogeneous with ADH type 1 (ADH1), the predominant form, being caused by germline gain-of-function mutations of the G-protein coupled calcium-sensing receptor (CaSR), and ADH2 caused by germline gain-of-function mutations of G-protein subunit α-11 (Gα11 ). To date Gα11 mutations causing ADH2 have been reported in only five probands. We investigated a multigenerational nonconsanguineous family, from Iran, with ADH and keratoconus which are not known to be associated, for causative mutations by whole-exome sequencing in two individuals with hypoparathyroidism, of whom one also had keratoconus, followed by cosegregation analysis of variants. This identified a novel heterozygous germline Val340Met Gα11 mutation in both individuals, and this was also present in the other two relatives with hypocalcemia that were tested. Three-dimensional modeling revealed the Val340Met mutation to likely alter the conformation of the C-terminal α5 helix, which may affect G-protein coupled receptor binding and G-protein activation. In vitro functional expression of wild-type (Val340) and mutant (Met340) Gα11 proteins in HEK293 cells stably expressing the CaSR, demonstrated that the intracellular calcium responses following stimulation with extracellular calcium, of the mutant Met340 Gα11 led to a leftward shift of the concentration-response curve with a significantly (p < 0.0001) reduced mean half-maximal concentration (EC50 ) value of 2.44 mM (95% CI, 2.31 to 2.77 mM) when compared to the wild-type EC50 of 3.14 mM (95% CI, 3.03 to 3.26 mM), consistent with a gain-of-function mutation. A novel His403Gln variant in transforming growth factor, beta-induced (TGFBI), that may be causing keratoconus was also identified, indicating likely digenic inheritance of keratoconus and ADH2 in this family. In conclusion, our identification of a novel germline gain-of-function Gα11 mutation, Val340Met, causing ADH2 demonstrates the importance of the Gα11 C-terminal region for G-protein function and CaSR signal transduction. © 2016 American Society for Bone and Mineral Research.
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Affiliation(s)
- Sian E Piret
- Academic Endocrine Unit, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford, UK
| | - Caroline M Gorvin
- Academic Endocrine Unit, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford, UK
| | - Alistair T Pagnamenta
- Wellcome Trust Centre for Human Genetics, Roosevelt Drive, Oxford, UK.,Oxford NIHR Comprehensive Biomedical Research Centre, Oxford, UK
| | - Sarah A Howles
- Academic Endocrine Unit, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford, UK
| | - Treena Cranston
- Oxford University Hospitals NHS Trust, Oxford Medical Genetics Laboratories, Churchill Hospital, Oxford, UK
| | - Nigel Rust
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, UK
| | - M Andrew Nesbit
- Academic Endocrine Unit, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford, UK.,Biomedical Sciences Research Institute, Ulster University, Coleraine, UK
| | - Ben Glaser
- Department of Internal Medicine, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Jenny C Taylor
- Wellcome Trust Centre for Human Genetics, Roosevelt Drive, Oxford, UK.,Oxford NIHR Comprehensive Biomedical Research Centre, Oxford, UK
| | - Andreas E Buchs
- Department of Medicine D, Assaf Harofe Medical Center, Zerifin, Israel
| | - Fadil M Hannan
- Academic Endocrine Unit, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford, UK.,Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, UK
| | - Rajesh V Thakker
- Academic Endocrine Unit, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford, UK.,Oxford NIHR Comprehensive Biomedical Research Centre, Oxford, UK
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Gorvin CM, Cranston T, Hannan FM, Rust N, Qureshi A, Nesbit MA, Thakker RV. A G-protein Subunit-α11 Loss-of-Function Mutation, Thr54Met, Causes Familial Hypocalciuric Hypercalcemia Type 2 (FHH2). J Bone Miner Res 2016; 31:1200-6. [PMID: 26729423 PMCID: PMC4949650 DOI: 10.1002/jbmr.2778] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2015] [Revised: 01/02/2015] [Accepted: 01/04/2015] [Indexed: 11/29/2022]
Abstract
Familial hypocalciuric hypercalcemia (FHH) is a genetically heterogeneous disorder with three variants, FHH1 to FHH3. FHH1 is caused by loss-of-function mutations of the calcium-sensing receptor (CaSR), a G-protein coupled receptor that predominantly signals via G-protein subunit alpha-11 (Gα11 ) to regulate calcium homeostasis. FHH2 is the result of loss-of-function mutations in Gα11 , encoded by GNA11, and to date only two FHH2-associated Gα11 missense mutations (Leu135Gln and Ile200del) have been reported. FHH3 is the result of loss-of-function mutations of the adaptor protein-2 σ-subunit (AP2σ), which plays a pivotal role in clathrin-mediated endocytosis. We describe a 65-year-old woman who had hypercalcemia with normal circulating parathyroid hormone concentrations and hypocalciuria, features consistent with FHH, but she did not have CaSR and AP2σ mutations. Mutational analysis of the GNA11 gene was therefore undertaken, using leucocyte DNA, and this identified a novel heterozygous GNA11 mutation (c.161C>T; p.Thr54Met). The effect of the Gα11 variant was assessed by homology modeling of the related Gαq protein and by measuring the CaSR-mediated intracellular calcium (Ca(2+) i ) responses of HEK293 cells, stably expressing CaSR, to alterations in extracellular calcium (Ca(2+) o ) using flow cytometry. Three-dimensional modeling revealed the Thr54Met mutation to be located at the interface between the Gα11 helical and GTPase domains, and to likely impair GDP binding and interdomain interactions. Expression of wild-type and the mutant Gα11 in HEK293 cells stably expressing CaSR demonstrate that the Ca(2+) i responses after stimulation with Ca(2+) o of the mutant Met54 Gα11 led to a rightward shift of the concentration-response curve with a significantly (p < 0.01) increased mean half-maximal concentration (EC50 ) value of 3.88 mM (95% confidence interval [CI] 3.76-4.01 mM), when compared with the wild-type EC50 of 2.94 mM (95% CI 2.81-3.07 mM) consistent with a loss-of-function. Thus, our studies have identified a third Gα11 mutation (Thr54Met) causing FHH2 and reveal a critical role for the Gα11 interdomain interface in CaSR signaling and Ca(2+) o homeostasis. © 2016 American Society for Bone and Mineral Research.
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Affiliation(s)
- Caroline M Gorvin
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Treena Cranston
- Oxford Molecular Genetics Laboratory, Churchill Hospital, Oxford, UK
| | - Fadil M Hannan
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.,Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, UK
| | - Nigel Rust
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Asjid Qureshi
- Department of Diabetes and Endocrinology, Northwest London NHS Trust, London, UK
| | - M Andrew Nesbit
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.,School of Biomedical Sciences, University of Ulster, Coleraine, Londonderry, UK
| | - Rajesh V Thakker
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
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Howles SA, Hannan FM, Babinsky VN, Rogers A, Gorvin CM, Rust N, Richardson T, McKenna MJ, Nesbit MA, Thakker RV. Cinacalcet for Symptomatic Hypercalcemia Caused by AP2S1 Mutations. N Engl J Med 2016; 374:1396-1398. [PMID: 27050234 PMCID: PMC4972445 DOI: 10.1056/nejmc1511646] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
| | | | | | | | | | - Nigel Rust
- University of Oxford Oxford, United Kingdom
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Babinsky VN, Hannan FM, Gorvin CM, Howles SA, Nesbit MA, Rust N, Hanyaloglu AC, Hu J, Spiegel AM, Thakker RV. Allosteric Modulation of the Calcium-sensing Receptor Rectifies Signaling Abnormalities Associated with G-protein α-11 Mutations Causing Hypercalcemic and Hypocalcemic Disorders. J Biol Chem 2016; 291:10876-85. [PMID: 26994139 PMCID: PMC4865932 DOI: 10.1074/jbc.m115.696401] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2015] [Indexed: 11/06/2022] Open
Abstract
Germline loss- and gain-of-function mutations of G-protein α-11 (Gα11), which couples the calcium-sensing receptor (CaSR) to intracellular calcium (Ca2+i) signaling, lead to familial hypocalciuric hypercalcemia type 2 (FHH2) and autosomal dominant hypocalcemia type 2 (ADH2), respectively, whereas somatic Gα11 mutations mediate uveal melanoma development by constitutively up-regulating MAPK signaling. Cinacalcet and NPS-2143 are allosteric CaSR activators and inactivators, respectively, that ameliorate signaling disturbances associated with CaSR mutations, but their potential to modulate abnormalities of the downstream Gα11 protein is unknown. This study investigated whether cinacalcet and NPS-2143 may rectify Ca2+i alterations associated with FHH2- and ADH2-causing Gα11 mutations, and evaluated the influence of germline gain-of-function Gα11 mutations on MAPK signaling by measuring ERK phosphorylation, and assessed the effect of NPS-2143 on a uveal melanoma Gα11 mutant. WT and mutant Gα11 proteins causing FHH2, ADH2 or uveal melanoma were transfected in CaSR-expressing HEK293 cells, and Ca2+i and ERK phosphorylation responses measured by flow-cytometry and Alphascreen immunoassay following exposure to extracellular Ca2+ (Ca2+o) and allosteric modulators. Cinacalcet and NPS-2143 rectified the Ca2+i responses of FHH2- and ADH2-associated Gα11 loss- and gain-of-function mutations, respectively. ADH2-causing Gα11 mutations were demonstrated not to be constitutively activating and induced ERK phosphorylation following Ca2+o stimulation only. The increased ERK phosphorylation associated with ADH2 and uveal melanoma mutants was rectified by NPS-2143. These findings demonstrate that CaSR-targeted compounds can rectify signaling disturbances caused by germline and somatic Gα11 mutations, which respectively lead to calcium disorders and tumorigenesis; and that ADH2-causing Gα11 mutations induce non-constitutive alterations in MAPK signaling.
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Affiliation(s)
- Valerie N Babinsky
- From the Radcliffe Department of Medicine, University of Oxford, Oxford OX3 7LJ, United Kingdom
| | - Fadil M Hannan
- From the Radcliffe Department of Medicine, University of Oxford, Oxford OX3 7LJ, United Kingdom, Department of Musculoskeletal Biology, University of Liverpool, Liverpool L69 3GA, United Kingdom
| | - Caroline M Gorvin
- From the Radcliffe Department of Medicine, University of Oxford, Oxford OX3 7LJ, United Kingdom
| | - Sarah A Howles
- From the Radcliffe Department of Medicine, University of Oxford, Oxford OX3 7LJ, United Kingdom
| | - M Andrew Nesbit
- From the Radcliffe Department of Medicine, University of Oxford, Oxford OX3 7LJ, United Kingdom, Biomedical Sciences Research Institute, Ulster University, Coleraine BT52 1SA, United Kingdom
| | - Nigel Rust
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom
| | - Aylin C Hanyaloglu
- Department of Surgery and Cancer, Institute of Reproductive Biology and Development, Imperial College London, London W12 0NN, United Kingdom
| | - Jianxin Hu
- Laboratory of Bioorganic Chemistry, NIDDK, National Institutes of Health, Bethesda, Maryland 20892, and
| | | | - Rajesh V Thakker
- From the Radcliffe Department of Medicine, University of Oxford, Oxford OX3 7LJ, United Kingdom,
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Hannan FM, Howles SA, Rogers A, Cranston T, Gorvin CM, Babinsky VN, Reed AA, Thakker CE, Bockenhauer D, Brown RS, Connell JM, Cook J, Darzy K, Ehtisham S, Graham U, Hulse T, Hunter SJ, Izatt L, Kumar D, McKenna MJ, McKnight JA, Morrison PJ, Mughal MZ, O'Halloran D, Pearce SH, Porteous ME, Rahman M, Richardson T, Robinson R, Scheers I, Siddique H, Van't Hoff WG, Wang T, Whyte MP, Nesbit MA, Thakker RV. Adaptor protein-2 sigma subunit mutations causing familial hypocalciuric hypercalcaemia type 3 (FHH3) demonstrate genotype-phenotype correlations, codon bias and dominant-negative effects. Hum Mol Genet 2015; 24:5079-92. [PMID: 26082470 PMCID: PMC4550820 DOI: 10.1093/hmg/ddv226] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Accepted: 06/12/2015] [Indexed: 12/05/2022] Open
Abstract
The adaptor protein-2 sigma subunit (AP2σ2) is pivotal for clathrin-mediated endocytosis of plasma membrane constituents such as the calcium-sensing receptor (CaSR). Mutations of the AP2σ2 Arg15 residue result in familial hypocalciuric hypercalcaemia type 3 (FHH3), a disorder of extracellular calcium (Ca2+o) homeostasis. To elucidate the role of AP2σ2 in Ca2+o regulation, we investigated 65 FHH probands, without other FHH-associated mutations, for AP2σ2 mutations, characterized their functional consequences and investigated the genetic mechanisms leading to FHH3. AP2σ2 mutations were identified in 17 probands, comprising 5 Arg15Cys, 4 Arg15His and 8 Arg15Leu mutations. A genotype–phenotype correlation was observed with the Arg15Leu mutation leading to marked hypercalcaemia. FHH3 probands harboured additional phenotypes such as cognitive dysfunction. All three FHH3-causing AP2σ2 mutations impaired CaSR signal transduction in a dominant-negative manner. Mutational bias was observed at the AP2σ2 Arg15 residue as other predicted missense substitutions (Arg15Gly, Arg15Pro and Arg15Ser), which also caused CaSR loss-of-function, were not detected in FHH probands, and these mutations were found to reduce the numbers of CaSR-expressing cells. FHH3 probands had significantly greater serum calcium (sCa) and magnesium (sMg) concentrations with reduced urinary calcium to creatinine clearance ratios (CCCR) in comparison with FHH1 probands with CaSR mutations, and a calculated index of sCa × sMg/100 × CCCR, which was ≥ 5.0, had a diagnostic sensitivity and specificity of 83 and 86%, respectively, for FHH3. Thus, our studies demonstrate AP2σ2 mutations to result in a more severe FHH phenotype with genotype–phenotype correlations, and a dominant-negative mechanism of action with mutational bias at the Arg15 residue.
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Affiliation(s)
- Fadil M Hannan
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Sarah A Howles
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Angela Rogers
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Treena Cranston
- Oxford Molecular Genetics Laboratory, Churchill Hospital, Oxford, UK
| | - Caroline M Gorvin
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Valerie N Babinsky
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Anita A Reed
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Clare E Thakker
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Detlef Bockenhauer
- Renal Unit, Great Ormond Street Hospital for Children NHS Foundation Trust and UCL Institute of Child Health, London, UK
| | - Rosalind S Brown
- Division of Endocrinology, Boston Children's Hospital, Boston, MA, USA
| | - John M Connell
- School of Medicine, Ninewells Hospital, University of Dundee, Dundee, UK
| | - Jacqueline Cook
- Clinical Genetics Department, Sheffield Children's Hospital NHS Foundation Trust, Sheffield, UK
| | - Ken Darzy
- Queen Elizabeth II Hospital, Welwyn Garden City, UK
| | - Sarah Ehtisham
- Department of Paediatric Endocrinology, Royal Manchester Children's Hospital, Manchester, UK
| | - Una Graham
- Regional Centre for Endocrinology and Diabetes, Royal Victoria Hospital, Belfast, UK
| | - Tony Hulse
- Department of Paediatrics, Evelina London Children's Hospital, St. Thomas' Hospital, London, UK
| | - Steven J Hunter
- Regional Centre for Endocrinology and Diabetes, Royal Victoria Hospital, Belfast, UK
| | - Louise Izatt
- Department of Clinical Genetics, Guy's Hospital, London, UK
| | - Dhavendra Kumar
- Institute of Cancer and Genetics, University Hospital of Wales, Cardiff, UK
| | - Malachi J McKenna
- Department of Endocrinology, St. Vincent's University Hospital, Dublin, Ireland
| | - John A McKnight
- Metabolic Unit, Western General Hospital, NHS Lothian and University of Edinburgh, Edinburgh, UK
| | - Patrick J Morrison
- Centre for Cancer Research and Cell Biology, Queens University of Belfast, Belfast, UK, Department of Genetic Medicine, Belfast HSC Trust, Belfast, UK
| | - M Zulf Mughal
- Department of Paediatric Endocrinology, Royal Manchester Children's Hospital, Manchester, UK
| | | | - Simon H Pearce
- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Mary E Porteous
- SE Scotland Genetic Service, Western General Hospital, Edinburgh, UK
| | - Mushtaqur Rahman
- Department of Endocrinology, Northwick Park Hospital, London, UK
| | - Tristan Richardson
- Diabetes and Endocrine Centre, Royal Bournemouth Hospital, Bournemouth, UK
| | - Robert Robinson
- Department of Endocrinology, Chesterfield Royal Hospital NHS Foundation Trust, Derbyshire, UK
| | - Isabelle Scheers
- Pediatric Gastroenterology, Hepatology and Nutrition Unit, Cliniques Universitaires Saint-Luc, Brussels, Belgium
| | - Haroon Siddique
- Department of Endocrinology, Russells Hall Hospital, Dudley, UK
| | - William G Van't Hoff
- Renal Unit, Great Ormond Street Hospital for Children NHS Foundation Trust and UCL Institute of Child Health, London, UK
| | - Timothy Wang
- Department of Clinical Biochemistry, Frimley Park Hospital, Surrey, UK and
| | - Michael P Whyte
- Center for Metabolic Bone Disease and Molecular Research, Shriners Hospital for Children, St. Louis, Missouri, USA
| | - M Andrew Nesbit
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Rajesh V Thakker
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, UK,
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Abstract
Investigations over two decades have revised understanding of the prolactin hormone. Long thought to be merely a lactogenic hormone, its list of functions has been extended to include: reproduction, islet differentiation, adipocyte control and immune modulation. Prolactin functions by binding cell-surface expressed prolactin receptor, initiating signaling cascades, primarily utilizing Janus kinase-signal transducer and activator of transcription (JAK-STAT). Pathway disruption has been implicated in tumorigenesis, reproductive abnormalities, and diabetes. Prolactin can also be secreted from extrapituitary sources adding complexity to understanding of its physiological functions. This review aims to describe how prolactin exerts its pathophysiological roles by endocrine and autocrine means.
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Affiliation(s)
- Caroline M Gorvin
- Academic Endocrine Unit, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, Oxford, OX3 7LJ, UK
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Rogers A, Nesbit MA, Hannan FM, Howles SA, Gorvin CM, Cranston T, Allgrove J, Bevan JS, Bano G, Brain C, Datta V, Grossman AB, Hodgson SV, Izatt L, Millar-Jones L, Pearce SH, Robertson L, Selby PL, Shine B, Snape K, Warner J, Thakker RV. Mutational analysis of the adaptor protein 2 sigma subunit (AP2S1) gene: search for autosomal dominant hypocalcemia type 3 (ADH3). J Clin Endocrinol Metab 2014; 99:E1300-5. [PMID: 24708097 PMCID: PMC4447854 DOI: 10.1210/jc.2013-3909] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Autosomal dominant hypocalcemia (ADH) types 1 and 2 are due to calcium-sensing receptor (CASR) and G-protein subunit-α11 (GNA11) gain-of-function mutations, respectively, whereas CASR and GNA11 loss-of-function mutations result in familial hypocalciuric hypercalcemia (FHH) types 1 and 2, respectively. Loss-of-function mutations of adaptor protein-2 sigma subunit (AP2σ 2), encoded by AP2S1, cause FHH3, and we therefore sought for gain-of-function AP2S1 mutations that may cause an additional form of ADH, which we designated ADH3. OBJECTIVE The objective of the study was to investigate the hypothesis that gain-of-function AP2S1 mutations may cause ADH3. DESIGN The sample size required for the detection of at least one mutation with a greater than 95% likelihood was determined by binomial probability analysis. Nineteen patients (including six familial cases) with hypocalcemia in association with low or normal serum PTH concentrations, consistent with ADH, but who did not have CASR or GNA11 mutations, were ascertained. Leukocyte DNA was used for sequence and copy number variation analysis of AP2S1. RESULTS Binomial probability analysis, using the assumption that AP2S1 mutations would occur in hypocalcemic patients at a prevalence of 20%, which is observed in FHH patients without CASR or GNA11 mutations, indicated that the likelihood of detecting at least one AP2S1 mutation was greater than 95% and greater than 98% in sample sizes of 14 and 19 hypocalcemic patients, respectively. AP2S1 mutations and copy number variations were not detected in the 19 hypocalcemic patients. CONCLUSION The absence of AP2S1 abnormalities in hypocalcemic patients, suggests that ADH3 may not occur or otherwise represents a rare hypocalcemic disorder.
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Affiliation(s)
- Angela Rogers
- Academic Endocrine Unit (A.R., M.A.N., F.M.H., S.A.H., C.M.G., R.V.T.), Nuffield Department of Clinical Medicine, and Academic Endocrine Unit (A.R., M.A.N., F.M.H., S.A.H., C.M.G., R.V.T.), Radcliffe Department of Medicine, University of Oxford, Oxford OX3 7LJ, United Kingdom; Oxford Molecular Genetics Laboratory (T.C.) and Oxford Centre for Diabetes, Endocrinology, and Metabolism (A.B.G.), Churchill Hospital, Oxford OX3 7LJ, United Kingdom; Department of Paediatric Endocrinology (J.A., C.B.), Great Ormond Street Hospital, London WC1N 3JH, United Kingdom; Department of Paediatric Endocrinology (J.A.), Royal London Hospital, London E1 1BB, United Kingdom; Department of Endocrinology (J.S.B.), Aberdeen Royal Infirmary, Aberdeen AB25 2ZN, United Kingdom; Departments of Diabetes and Endocrinology (G.B.) and Clinical Genetics (S.V.H., K.S.), St George's Hospital, London SW17 0RE, United Kingdom; Jenny Lind Children's Department (V.D.), Norfolk and Norwich University Hospitals National Health Service Foundation Trust, Norfolk NR4 7UY, United Kingdom; Department of Clinical Genetics (L.I.), Guy's and St Thomas' Foundation Trust, Guy's Hospital, London SE1 9RT, United Kingdom; Department of Paediatrics (L.M.-J.), Royal Glamorgan Hospital, Glamorgan CF72 8XR, United Kingdom; Endocrine Unit (S.H.P.), Royal Victoria Infirmary, Newcastle upon Tyne NE1 4LP, United Kingdom; Department of Clinical Genetics (L.R.), Leicester Royal Infirmary, Leicester LE1 5WW, United Kingdom; Department of Medicine (P.L.S.), Manchester Royal Infirmary, Manchester M13 9WL, United Kingdom; Department of Clinical Biochemistry (B.S.), John Radcliffe Hospital, Oxford OX3 9DU, United Kingdom; and Department of Paediatrics (J.W.), University Hospital of Wales, Cardiff CF14 4XW, United Kingdom
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