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Hassan A, Khalaily N, Kilav-Levin R, Del Castello B, Manley NR, Ben-Dov IZ, Naveh-Many T. Dicer-Mediated mTORC1 Signaling and Parathyroid Gland Integrity and Function. J Am Soc Nephrol 2024:00001751-990000000-00339. [PMID: 38819931 DOI: 10.1681/asn.0000000000000394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 05/20/2024] [Indexed: 06/02/2024] Open
Abstract
Key Points
Maintaining parathyroid gland integrity is a dynamic process regulated by the parathyroid microRNA–mechanistic target of rapamycin complex 1 axis.This axis is essential for preserving intact parathyroid glands throughout life, with relevance to CKD-induced secondary hyperparathyroidism.
Background
Secondary hyperparathyroidism of CKD contributes significantly to patient morbidity and mortality. The underlining mechanisms of CKD-induced secondary hyperparathyroidism remain elusive. We previously demonstrated that PT-Dicer
−/−
mice, with parathyroid-specific deletion of the microRNA (miRNA)-processing enzyme Dicer and consequently miRNA, maintain normal basal serum parathyroid hormone (PTH) levels but do not develop secondary hyperparathyroidism induced by CKD. In addition, we showed that the parathyroid mechanistic target of rapamycin complex 1 (mTORC1) pathway is activated in CKD. We now explored the roles of Dicer/miRNA and mTORC1 in parathyroid development and function.
Methods
We generated mice with parathyroid-specific Dicer (PT-Dicer
−/−
), mechanistic target of rapamycin (PT-mTOR
−/−
), or tuberous sclerosis complex 1 (PT-Tsc1
−/−
) deficiency combined with yellow fluorescent protein (YFP) or tdTomato expression to identify the parathyroids by fluorescence microscopy. CKD was induced by an adenine-rich high-phosphate diet.
Results
Despite normal basal serum PTH levels, PT-Dicer
−/−
mice displayed apoptotic loss of intact parathyroid glands postnatally and reduced mechanistic target of rapamycin activity. PT-mTOR
−/−
mice lacked intact parathyroid glands yet maintained normal serum PTH levels, mirroring the phenotype of PT-Dicer
−/−
mice. Conversely, PT-Tsc1
−/−
mice with hyperactivated mTORC1 exhibited enlarged glands along with elevated basal serum PTH and calcium levels. Significantly, PT-Dicer
−/−
;Tsc1
−/−
double knockout mice preserved intact parathyroid glands and reinstated CKD-induced secondary hyperparathyroidism.
Conclusions
mTORC1 operates downstream of Dicer and miRNA in the parathyroid and is essential for maintaining postnatal parathyroid gland integrity throughout life and for the pathogenesis of CKD-induced secondary hyperparathyroidism.
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Affiliation(s)
- Alia Hassan
- Minerva Center for Bone and Mineral Research, Nephrology Services, Hadassah Hebrew University Medical Center and Faculty of Medicine, Jerusalem, Israel
| | - Nareman Khalaily
- Minerva Center for Bone and Mineral Research, Nephrology Services, Hadassah Hebrew University Medical Center and Faculty of Medicine, Jerusalem, Israel
| | - Rachel Kilav-Levin
- Minerva Center for Bone and Mineral Research, Nephrology Services, Hadassah Hebrew University Medical Center and Faculty of Medicine, Jerusalem, Israel
- School of Nursing, Jerusalem College of Technology, Faculty of Life and Health Sciences, Jerusalem, Israel
| | - Barbara Del Castello
- Department of Genetics, University of Georgia, Athens, Georgia
- CRDF Global, Arlington, Virginia
| | - Nancy Ruth Manley
- Department of Genetics, University of Georgia, Athens, Georgia
- Current address: School of Life Sciences, Arizona State University, Tempe, Arizona
| | - Iddo Z Ben-Dov
- Laboratory of Medical Transcriptomics, Nephrology and Internal Medicine B, Hadassah Hebrew University Medical Center and Faculty of Medicine, Jerusalem, Israel
| | - Tally Naveh-Many
- Minerva Center for Bone and Mineral Research, Nephrology Services, Hadassah Hebrew University Medical Center and Faculty of Medicine, Jerusalem, Israel
- Wohl Institute for Translational Medicine, Hadassah Hebrew University Medical Center, Jerusalem, Israel
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2
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Inchingolo F, Ferrara I, Viapiano F, Ciocia AM, Palumbo I, Guglielmo M, Inchingolo AD, Palermo A, Bordea IR, Inchingolo AM, Di Venere D, Dipalma G. Primary Failure Eruption: Genetic Investigation, Diagnosis and Treatment: A Systematic Review. CHILDREN (BASEL, SWITZERLAND) 2023; 10:1781. [PMID: 38002872 PMCID: PMC10670730 DOI: 10.3390/children10111781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 10/21/2023] [Accepted: 10/29/2023] [Indexed: 11/26/2023]
Abstract
AIM The aim of this systematic review is to explore the pathology, diagnosis, treatment, and genetic basis of Primary Failure of Eruption (PFE) in the field of pediatric dentistry and orthodontics. METHODS The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed for this review. The databases PubMed, Science Direct, Scopus, and Web of Science were searched from 1 July 2013 to 1 July 2023, using keywords "primary failure of tooth eruption" OR "primary failure of eruption" OR "tooth eruption failure" OR "PFE" AND "orthodontics". The study selection process involved screening articles based on the inclusion and exclusion criteria. RESULTS A total of 1151 results were obtained from the database search, with 14 papers meeting the inclusion criteria. The review covers various aspects of PFE, including its clinical features, diagnosis, treatment options, and genetic associations with mutations in the PTH1R gene. Differentiation between PFE and Mechanical Failure of Eruption (MFE) is crucial for accurate treatment planning. Orthodontic and surgical interventions, along with multidisciplinary approaches, have been employed to manage PFE cases. Genetic testing for PTH1R mutations plays a significant role in confirming the diagnosis and guiding treatment decisions, although some cases may not be linked to this mutation. CONCLUSIONS This systematic review provides valuable insights into the diagnosis, treatment, and genetic basis of PFE. Early diagnosis and personalized treatment planning are crucial for successful management. Genetic testing for PTH1R mutations aids in accurate diagnosis and may influence treatment decisions. However, further research is needed to explore the complex genetic basis of PFE fully and improve treatment outcomes for affected individuals.
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Affiliation(s)
- Francesco Inchingolo
- Department of Interdisciplinary Medicine, School of Medicine, University of Bari “Aldo Moro”, 70124 Bari, Italy; (I.F.); (F.V.); (A.M.C.); (I.P.); (M.G.); (A.D.I.); (A.M.I.); (D.D.V.); (G.D.)
| | - Irene Ferrara
- Department of Interdisciplinary Medicine, School of Medicine, University of Bari “Aldo Moro”, 70124 Bari, Italy; (I.F.); (F.V.); (A.M.C.); (I.P.); (M.G.); (A.D.I.); (A.M.I.); (D.D.V.); (G.D.)
| | - Fabio Viapiano
- Department of Interdisciplinary Medicine, School of Medicine, University of Bari “Aldo Moro”, 70124 Bari, Italy; (I.F.); (F.V.); (A.M.C.); (I.P.); (M.G.); (A.D.I.); (A.M.I.); (D.D.V.); (G.D.)
| | - Anna Maria Ciocia
- Department of Interdisciplinary Medicine, School of Medicine, University of Bari “Aldo Moro”, 70124 Bari, Italy; (I.F.); (F.V.); (A.M.C.); (I.P.); (M.G.); (A.D.I.); (A.M.I.); (D.D.V.); (G.D.)
| | - Irene Palumbo
- Department of Interdisciplinary Medicine, School of Medicine, University of Bari “Aldo Moro”, 70124 Bari, Italy; (I.F.); (F.V.); (A.M.C.); (I.P.); (M.G.); (A.D.I.); (A.M.I.); (D.D.V.); (G.D.)
| | - Mariafrancesca Guglielmo
- Department of Interdisciplinary Medicine, School of Medicine, University of Bari “Aldo Moro”, 70124 Bari, Italy; (I.F.); (F.V.); (A.M.C.); (I.P.); (M.G.); (A.D.I.); (A.M.I.); (D.D.V.); (G.D.)
| | - Alessio Danilo Inchingolo
- Department of Interdisciplinary Medicine, School of Medicine, University of Bari “Aldo Moro”, 70124 Bari, Italy; (I.F.); (F.V.); (A.M.C.); (I.P.); (M.G.); (A.D.I.); (A.M.I.); (D.D.V.); (G.D.)
| | - Andrea Palermo
- College of Medicine and Dentistry, Birmingham B4 6BN, UK;
| | - Ioana Roxana Bordea
- Department of Oral Health, Iuliu Hatieganu University of Medicine and Pharmacy, 15 V. Babes Street, 400012 Cluj-Napoca, Romania;
| | - Angelo Michele Inchingolo
- Department of Interdisciplinary Medicine, School of Medicine, University of Bari “Aldo Moro”, 70124 Bari, Italy; (I.F.); (F.V.); (A.M.C.); (I.P.); (M.G.); (A.D.I.); (A.M.I.); (D.D.V.); (G.D.)
| | - Daniela Di Venere
- Department of Interdisciplinary Medicine, School of Medicine, University of Bari “Aldo Moro”, 70124 Bari, Italy; (I.F.); (F.V.); (A.M.C.); (I.P.); (M.G.); (A.D.I.); (A.M.I.); (D.D.V.); (G.D.)
| | - Gianna Dipalma
- Department of Interdisciplinary Medicine, School of Medicine, University of Bari “Aldo Moro”, 70124 Bari, Italy; (I.F.); (F.V.); (A.M.C.); (I.P.); (M.G.); (A.D.I.); (A.M.I.); (D.D.V.); (G.D.)
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Cazorla-Vázquez S, Kösters P, Bertz S, Pfister F, Daniel C, Dedden M, Zundler S, Jobst-Schwan T, Amann K, Engel FB. Adhesion GPCR Gpr126 (Adgrg6) Expression Profiling in Zebrafish, Mouse, and Human Kidney. Cells 2023; 12:1988. [PMID: 37566066 PMCID: PMC10417176 DOI: 10.3390/cells12151988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 07/22/2023] [Accepted: 07/29/2023] [Indexed: 08/12/2023] Open
Abstract
Adhesion G protein-coupled receptors (aGPCRs) comprise the second-largest class of GPCRs, the most common target for approved pharmacological therapies. aGPCRs play an important role in development and disease and have recently been associated with the kidney. Several aGPCRs are expressed in the kidney and some aGPCRs are either required for kidney development or their expression level is altered in diseased kidneys. Yet, general aGPCR function and their physiological role in the kidney are poorly understood. Here, we characterize in detail Gpr126 (Adgrg6) expression based on RNAscope® technology in zebrafish, mice, and humans during kidney development in adults. Gpr126 expression is enriched in the epithelial linage during nephrogenesis and persists in the adult kidney in parietal epithelial cells, collecting ducts, and urothelium. Single-cell RNAseq analysis shows that gpr126 expression is detected in zebrafish in a distinct ionocyte sub-population. It is co-detected selectively with slc9a3.2, slc4a4a, and trpv6, known to be involved in apical acid secretion, buffering blood or intracellular pH, and to maintain high cytoplasmic Ca2+ concentration, respectively. Furthermore, gpr126-expressing cells were enriched in the expression of potassium transporter kcnj1a.1 and gcm2, which regulate the expression of a calcium sensor receptor. Notably, the expression patterns of Trpv6, Kcnj1a.1, and Gpr126 in mouse kidneys are highly similar. Collectively, our approach permits a detailed insight into the spatio-temporal expression of Gpr126 and provides a basis to elucidate a possible role of Gpr126 in kidney physiology.
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Affiliation(s)
- Salvador Cazorla-Vázquez
- Experimental Renal and Cardiovascular Research, Department of Nephropathology, Institute of Pathology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany; (S.C.-V.); (P.K.)
| | - Peter Kösters
- Experimental Renal and Cardiovascular Research, Department of Nephropathology, Institute of Pathology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany; (S.C.-V.); (P.K.)
| | - Simone Bertz
- Institute of Pathology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany;
| | - Frederick Pfister
- Department of Nephropathology, Institute of Pathology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany; (F.P.); (C.D.); (K.A.)
| | - Christoph Daniel
- Department of Nephropathology, Institute of Pathology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany; (F.P.); (C.D.); (K.A.)
| | - Mark Dedden
- Department of Medicine 1, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany; (M.D.); (S.Z.)
| | - Sebastian Zundler
- Department of Medicine 1, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany; (M.D.); (S.Z.)
| | - Tilman Jobst-Schwan
- Department of Nephrology and Hypertension, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany;
- Research Center On Rare Kidney Diseases (RECORD), University Hospital Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany
| | - Kerstin Amann
- Department of Nephropathology, Institute of Pathology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany; (F.P.); (C.D.); (K.A.)
| | - Felix B. Engel
- Experimental Renal and Cardiovascular Research, Department of Nephropathology, Institute of Pathology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany; (S.C.-V.); (P.K.)
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Mannstadt M, Cianferotti L, Gafni RI, Giusti F, Kemp EH, Koch CA, Roszko KL, Yao L, Guyatt GH, Thakker RV, Xia W, Brandi ML. Hypoparathyroidism: Genetics and Diagnosis. J Bone Miner Res 2022; 37:2615-2629. [PMID: 36375809 DOI: 10.1002/jbmr.4667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 07/22/2022] [Accepted: 07/31/2022] [Indexed: 01/05/2023]
Abstract
This narrative report summarizes diagnostic criteria for hypoparathyroidism and describes the clinical presentation and underlying genetic causes of the nonsurgical forms. We conducted a comprehensive literature search from January 2000 to January 2021 and included landmark articles before 2000, presenting a comprehensive update of these topics and suggesting a research agenda to improve diagnosis and, eventually, the prognosis of the disease. Hypoparathyroidism, which is characterized by insufficient secretion of parathyroid hormone (PTH) leading to hypocalcemia, is diagnosed on biochemical grounds. Low albumin-adjusted calcium or ionized calcium with concurrent inappropriately low serum PTH concentration are the hallmarks of the disease. In this review, we discuss the characteristics and pitfalls in measuring calcium and PTH. We also undertook a systematic review addressing the utility of measuring calcium and PTH within 24 hours after total thyroidectomy to predict long-term hypoparathyroidism. A summary of the findings is presented here; results of the detailed systematic review are published separately in this issue of JBMR. Several genetic disorders can present with hypoparathyroidism, either as an isolated disease or as part of a syndrome. A positive family history and, in the case of complex diseases, characteristic comorbidities raise the clinical suspicion of a genetic disorder. In addition to these disorders' phenotypic characteristics, which include autoimmune diseases, we discuss approaches for the genetic diagnosis. © 2022 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)
- Michael Mannstadt
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Luisella Cianferotti
- Bone Metabolic Diseases Unit, Department of Experimental and Clinical Biomedical Sciences, University of Florence, Florence, Italy
| | - Rachel I Gafni
- National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
| | | | | | - Christian A Koch
- Department of Medicine/Endocrinology, Fox Chase Cancer Center, Philadelphia, PA, USA.,Department of Medicine/Endocrinology, The University of Tennessee Health Science Center, Memphis, TN, USA
| | - Kelly L Roszko
- National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
| | - Liam Yao
- Department of Health Research Methods, Evidence, and Impact, and Department of Medicine, McMaster University, Hamilton, Canada
| | - Gordon H Guyatt
- Department of Health Research Methods, Evidence, and Impact, and Department of Medicine, McMaster University, Hamilton, Canada
| | - Rajesh V Thakker
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), Churchill Hospital, Headington, Oxford, UK.,Oxford National Institute for Health Research (NIHR) Biomedical Research Centre, Oxford University Hospitals NHS Foundation Trust, John Radcliffe Hospital, Oxford, UK
| | - Weibo Xia
- Department of Endocrinology, Peking Union Medical Collage Hospital, Beijing, China
| | - Maria-Luisa Brandi
- Fondazione Italiana sulla Ricerca sulle Malattie dell'Osso (F.I.R.M.O. Foundation), Florence, Italy
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5
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Hou YC, Zheng CM, Chiu HW, Liu WC, Lu KC, Lu CL. Role of Calcimimetics in Treating Bone and Mineral Disorders Related to Chronic Kidney Disease. Pharmaceuticals (Basel) 2022; 15:ph15080952. [PMID: 36015101 PMCID: PMC9415417 DOI: 10.3390/ph15080952] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 07/25/2022] [Accepted: 07/27/2022] [Indexed: 12/17/2022] Open
Abstract
Renal osteodystrophy is common in patients with chronic kidney disease and end-stage renal disease and leads to the risks of fracture and extraosseous vascular calcification. Secondary hyperparathyroidism (SHPT) is characterized by a compensatory increase in parathyroid hormone (PTH) secretion in response to decreased renal phosphate excretion, resulting in potentiating bone resorption and decreased bone quantity and quality. Calcium-sensing receptors (CaSRs) are group C G-proteins and negatively regulate the parathyroid glands through (1) increasing CaSR insertion within the plasma membrane, (2) increasing 1,25-dihydroxy vitamin D3 within the kidney and parathyroid glands, (3) inhibiting fibroblast growth factor 23 (FGF23) in osteocytes, and (4) attenuating intestinal calcium absorption through Transient Receptor Potential Vanilloid subfamily member 6 (TRPV6). Calcimimetics (CaMs) decrease PTH concentrations without elevating the serum calcium levels or extraosseous calcification through direct interaction with cell membrane CaSRs. CaMs reduce osteoclast activity by reducing stress-induced oxidative autophagy and improving Wnt-10b release, which promotes the growth of osteoblasts and subsequent mineralization. CaMs also directly promote osteoblast proliferation and survival. Consequently, bone quality may improve due to decreased bone resorption and improved bone formation. CaMs modulate cardiovascular fibrosis, calcification, and renal fibrosis through different mechanisms. Therefore, CaMs assist in treating SHPT. This narrative review focuses on the role of CaMs in renal osteodystrophy, including their mechanisms and clinical efficacy.
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Affiliation(s)
- Yi-Chou Hou
- Division of Nephrology, Department of Medicine, Cardinal-Tien Hospital, School of Medicine, Fu-Jen Catholic University, New Taipei City 24205, Taiwan;
| | - Cai-Mei Zheng
- Division of Nephrology, Department of Internal Medicine, Shuang Ho Hospital, School of Medicine, College of Medicine, Taipei Medical University, New Taipei City 11031, Taiwan;
- TMU Research Centre of Urology and Kidney, Taipei Medical University, New Taipei City 11031, Taiwan;
| | - Hui-Wen Chiu
- TMU Research Centre of Urology and Kidney, Taipei Medical University, New Taipei City 11031, Taiwan;
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, New Taipei City 11031, Taiwan
- Department of Medical Research, Shuang Ho Hospital, Taipei Medical University, New Taipei City 11031, Taiwan
| | - Wen-Chih Liu
- Department of Biology and Anatomy, National Defense Medical Center, Taipei 11490, Taiwan;
- Section of Nephrology, Department of Medicine, Antai Medical Care Corporation, Anti Tian-Sheng Memorial Hospital, Pingtung 92842, Taiwan
| | - Kuo-Cheng Lu
- Division of Nephrology, Department of Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, School of Medicine, Buddhist Tzu Chi University, Hualien 97004, Taiwan
- Division of Nephrology, Department of Medicine, Fu-Jen Catholic University Hospital, School of Medicine, Fu-Jen Catholic University, New Taipei City 24205, Taiwan;
- Correspondence:
| | - Chien-Lin Lu
- Division of Nephrology, Department of Medicine, Fu-Jen Catholic University Hospital, School of Medicine, Fu-Jen Catholic University, New Taipei City 24205, Taiwan;
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6
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Hawkes CP, Al Jubeh JM, Li D, Tucker SE, Rajiyah T, Levine MA. Novel PTH Gene Mutations Causing Isolated Hypoparathyroidism. J Clin Endocrinol Metab 2022; 107:e2449-e2458. [PMID: 35165722 PMCID: PMC9113798 DOI: 10.1210/clinem/dgac086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Indexed: 11/19/2022]
Abstract
CONTEXT Parathyroid hormone (PTH) gene mutations represent a rare cause of familial isolated hypoparathyroidism (FIH). These defects can cause hypoparathyroidism with increased or decreased serum levels of PTH through 1) impaired PTH synthesis; 2) induction of parathyroid cell apoptosis; or 3) secretion of bioinactive PTH molecules. Eight pathogenic mutations of this gene have been described previously. OBJECTIVE Through describing 2 novel mutations of the PTH gene, we aim to extend the molecular basis for FIH and further refine the proposed mechanisms by which PTH mutations cause hypoparathyroidism. METHODS Proband case reports were compiled with extended family analysis. The probands in both kindreds presented before age 10 days with hypocalcemia and elevated phosphate levels. Proband A had low PTH levels, whereas these levels were elevated in Proband B. Proband B was initially diagnosed with pseudohypoparathyroidism. Methylation analysis was performed of CpG dinucleotides within 3 GNAS differentially methylated regions; whole-genome sequencing; and PTH infusion with analysis of nephrogenous 3',5'-cyclic adenosine 5'-monophosphate. RESULTS Proband A had a novel heterozygous sequence change in exon 2 of the PTH gene, c.46_47delinsAA (p.Ala16Lys), and proband B had a novel homozygous nucleotide transition in PTH exon 3 (c.128G > A; p.G43E) that led to replacement of glycine by glutamic acid at position 12 of PTH 1-84. PTH 1-34 infusion demonstrated that renal responsiveness to PTH was intact and not antagonized by circulating bioinactive PTH. CONCLUSION PTH gene mutations are uncommon causes of hypoparathyroidism, but can be misdiagnosed as disorders of gland development or receptor function if PTH levels are decreased or elevated, respectively. Genetic testing should be considered early in the diagnostic approach to these presentations.
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Affiliation(s)
- Colin P Hawkes
- Division of Endocrinology and Diabetes, The Children’s Hospital of Philadelphia (CHOP), Philadelphia, Pennsylvania, USA
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Paediatrics and Child Health, University College Cork, Cork, Ireland
| | - Jamal M Al Jubeh
- Department of Pediatrics, Sheikh Khalifa Medical City, Abu Dhabi, United Arab Emirates
| | - Dong Li
- Center for Applied Genomics, CHOP, Philadelphia, Pennsylvania, USA
| | - Susan E Tucker
- Section of Adult and Pediatric Endocrinology, Diabetes, and Metabolism, The University of Chicago, Chicago, Illinois, USA
| | - Tara Rajiyah
- Section of Adult and Pediatric Endocrinology, Diabetes, and Metabolism, The University of Chicago, Chicago, Illinois, USA
| | - Michael A Levine
- Division of Endocrinology and Diabetes, The Children’s Hospital of Philadelphia (CHOP), Philadelphia, Pennsylvania, USA
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Correspondence: Michael A. Levine, MD, Division of Pediatric Endocrinology and Diabetes, The Children’s Hospital of Philadelphia, ARC510A, 3615 Civic Center Blvd, Philadelphia, PA 19104, USA.
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7
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Vincze S, Peters NV, Kuo CL, Brown TC, Korah R, Murtha TD, Bellizzi J, Riccardi A, Parham K, Carling T, Costa-Guda J, Arnold A. GCM2 Variants in Familial and Multiglandular Primary Hyperparathyroidism. J Clin Endocrinol Metab 2022; 107:e2021-e2026. [PMID: 34967908 DOI: 10.1210/clinem/dgab929] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Indexed: 11/19/2022]
Abstract
CONTEXT Multiglandular and familial parathyroid disease constitute important fractions of primary hyperparathyroidism (PHPT). Germline missense variants of GCM2, a regulator of parathyroid development, were observed in familial isolated hyperparathyroidism and sporadic PHPT. However, as these previously reported GCM2 variants occur at relatively high frequencies in the population, understanding their potential clinical utility will require both additional penetrance data and functional evidence relevant to tumorigenicity. OBJECTIVE Determine the frequency of GCM2 variants of interest among patients with sporadic multigland or familial parathyroid disease and assess their penetrance. DESIGN AND PATIENTS DNA-encoding PHPT-associated GCM2 germline variants were polymerase chain reaction-amplified and sequenced from 107 patients with either sporadic multigland or suspected/confirmed familial parathyroid tumors. RESULTS GCM2 variants were observed in 9 of 107 cases (8.4%): Y282D in 4 patients (6.3%) with sporadic multigland disease; Y394S in 2 patients (11.1%) with familial PHPT and 3 (4.8%) with sporadic multigland disease. Compared with the general population, Y282D was enriched 5.9-fold in multigland disease, but its penetrance was very low (0.02%). Y394S was enriched 79-fold in sporadic multigland disease and 93-fold in familial PHPT, but its penetrance was low (1.33% and 1.04%, respectively). CONCLUSIONS Observed in vitro-activating GCM2 variant alleles are significantly overrepresented in PHPT patients with multiglandular or familial disease compared to the general population, yet penetrance values are very low; that is, most individuals with these variants in the population have a very low risk of developing PHPT. The potential clinical utility of detecting these GCM2 variants requires further investigation, including assessing their possible role as pathogenic/low-penetrance alleles.
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Affiliation(s)
- Sarah Vincze
- Center for Molecular Oncology, University of Connecticut School of Medicine, Farmington, CT, USA
| | - Nicholas V Peters
- Yale Endocrine Neoplasia Laboratory, Department of Surgery, Yale School of Medicine, New Haven, CT, USA
| | - Chia-Ling Kuo
- Biostatistics Center, Connecticut Institute for Clinical and Translational Science, University of Connecticut, Farmington, CT, USA
| | - Taylor C Brown
- Yale Endocrine Neoplasia Laboratory, Department of Surgery, Yale School of Medicine, New Haven, CT, USA
- Department of Surgery, Washington University School of Medicine, St. Louis, MO,USA
| | - Reju Korah
- Yale Endocrine Neoplasia Laboratory, Department of Surgery, Yale School of Medicine, New Haven, CT, USA
| | - Timothy D Murtha
- Yale Endocrine Neoplasia Laboratory, Department of Surgery, Yale School of Medicine, New Haven, CT, USA
| | - Justin Bellizzi
- Center for Molecular Oncology, University of Connecticut School of Medicine, Farmington, CT, USA
| | - Aaliyah Riccardi
- Center for Molecular Oncology, University of Connecticut School of Medicine, Farmington, CT, USA
- Department of Otolaryngology-Head and Neck Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Kourosh Parham
- Division of Otolaryngology-Head and Neck Surgery, Department of Surgery, University of Connecticut School of Medicine, Farmington, CT, USA
| | - Tobias Carling
- Biostatistics Center, Connecticut Institute for Clinical and Translational Science, University of Connecticut, Farmington, CT, USA
- Carling Adrenal Center, Hospital for Endocrine Surgery, Tampa, FL, USA
| | - Jessica Costa-Guda
- Center for Molecular Oncology, University of Connecticut School of Medicine, Farmington, CT, USA
- Center for Regenerative Medicine and Skeletal Development, University of Connecticut School of Dental Medicine, Farmington, CT, USA
| | - Andrew Arnold
- Center for Molecular Oncology, University of Connecticut School of Medicine, Farmington, CT, USA
- Division of Endocrinology and Metabolism, University of Connecticut School of Medicine, Farmington, CT, USA
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8
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Canaff L, Guarnieri V, Kim Y, Wong BYL, Nolin-Lapalme A, Cole DEC, Minisola S, Eller-Vainicher C, Cetani F, Repaci A, Turchetti D, Corbetta S, Scillitani A, Goltzman D. Novel Glial Cells Missing-2 (GCM2) variants in parathyroid disorders. Eur J Endocrinol 2022; 186:351-366. [PMID: 35038313 DOI: 10.1016/10.1530/eje-21-0433] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 01/13/2022] [Indexed: 05/25/2023]
Abstract
OBJECTIVE The aim of this study was to analyze variants of the gene glial cells missing-2 (GCM2), encoding a parathyroid cell-specific transcription factor, in familial hypoparathyroidism and in familial isolated hyperparathyroidism (FIHP) without and with parathyroid carcinoma. DESIGN We characterized 2 families with hypoparathyroidism and 19 with FIHP in which we examined the mechanism of action of GCM2 variants. METHODS Leukocyte DNA of hypoparathyroid individuals was Sanger sequenced for CASR, PTH, GNA11 and GCM2 mutations. DNA of hyperparathyroid individuals underwent MEN1, CDKN1B, CDC73, CASR, RET and GCM2 sequencing. The actions of identified GCM2 variants were evaluated by in vitro functional analyses. RESULTS A novel homozygous p.R67C GCM2 mutation which failed to stimulate transcriptional activity in a luciferase assay was identified in affected members of two hypoparathyroid families. Oligonucleotide pull-down assay and in silico structural modeling indicated that this mutant had lost the ability to bind the consensus GCM recognition sequence of DNA. Two novel (p.I383M and p.T386S) and one previously reported (p.Y394S) heterozygous GCM2 variants that lie within a C-terminal conserved inhibitory domain were identified in three affected individuals of the hyperparathyroid families. One family member, heterozygous for p.I138M, had parathyroid carcinoma (PC), and a heterozygous p.V382M variant was found in another patient affected by sporadic PC. These variants exerted significantly enhanced in vitrotranscriptional activity, including increased stimulation of the PTH promoter. CONCLUSIONS We provide evidence that two novel GCM2 R67C inactivating mutations with an inability to bind DNA are causative of hypoparathyroidism. Additionally, we provide evidence that two novel GCM2 variants increased transactivation of the PTH promoter in vitro and are associated with FIHP. Furthermore, our studies suggest that activating GCM2 variants may contribute to facilitating more aggressive parathyroid disease.
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Affiliation(s)
- Lucie Canaff
- Metabolic Complications and Disorders, Research Institute-McGill University Health Centre, Montreal, Quebec, Canada
| | - Vito Guarnieri
- Division of Medical Genetics and Unit of Endocrinology, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Yoojung Kim
- Metabolic Complications and Disorders, Research Institute-McGill University Health Centre, Montreal, Quebec, Canada
| | - Betty Y L Wong
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Alexis Nolin-Lapalme
- Metabolic Complications and Disorders, Research Institute-McGill University Health Centre, Montreal, Quebec, Canada
| | - David E C Cole
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Salvatore Minisola
- Department of Internal Medicine and Medical Disciplines, 'Sapienza' Rome University, Rome, Italy
| | - Cristina Eller-Vainicher
- Department of Medical Sciences and Community, Fondazione Ca'Granda IRCCS Ospedale Maggiore Policlinico, Milan, Italy
| | | | - Andrea Repaci
- Unit of Endocrinology, S. Orsola Malpighi Hospital, Bologna, Italy
| | - Daniela Turchetti
- Center for the Studies of Hereditary Cancers, Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy
| | - Sabrina Corbetta
- Endocrinology and Diabetology Service, IRCCS Istituto Ortopedico Galeazzi, Milan, Italy
- Department of Biomedical, Surgical and Dental Sciences, University of Milan, Milan, Italy
| | - Alfredo Scillitani
- Division of Medical Genetics and Unit of Endocrinology, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - David Goltzman
- Metabolic Complications and Disorders, Research Institute-McGill University Health Centre, Montreal, Quebec, Canada
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9
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Canaff L, Guarnieri V, Kim Y, Wong BYL, Nolin-Lapalme A, Cole DEC, Minisola S, Eller-Vainicher C, Cetani F, Repaci A, Turchetti D, Corbetta S, Scillitani A, Goltzman D. Novel Glial Cells Missing-2 (GCM2) variants in parathyroid disorders. Eur J Endocrinol 2022; 186:351-366. [PMID: 35038313 PMCID: PMC8859918 DOI: 10.1530/eje-21-0433] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 01/13/2022] [Indexed: 11/08/2022]
Abstract
OBJECTIVE The aim of this study was to analyze variants of the gene glial cells missing-2 (GCM2), encoding a parathyroid cell-specific transcription factor, in familial hypoparathyroidism and in familial isolated hyperparathyroidism (FIHP) without and with parathyroid carcinoma. DESIGN We characterized 2 families with hypoparathyroidism and 19 with FIHP in which we examined the mechanism of action of GCM2 variants. METHODS Leukocyte DNA of hypoparathyroid individuals was Sanger sequenced for CASR, PTH, GNA11 and GCM2 mutations. DNA of hyperparathyroid individuals underwent MEN1, CDKN1B, CDC73, CASR, RET and GCM2 sequencing. The actions of identified GCM2 variants were evaluated by in vitro functional analyses. RESULTS A novel homozygous p.R67C GCM2 mutation which failed to stimulate transcriptional activity in a luciferase assay was identified in affected members of two hypoparathyroid families. Oligonucleotide pull-down assay and in silico structural modeling indicated that this mutant had lost the ability to bind the consensus GCM recognition sequence of DNA. Two novel (p.I383M and p.T386S) and one previously reported (p.Y394S) heterozygous GCM2 variants that lie within a C-terminal conserved inhibitory domain were identified in three affected individuals of the hyperparathyroid families. One family member, heterozygous for p.I138M, had parathyroid carcinoma (PC), and a heterozygous p.V382M variant was found in another patient affected by sporadic PC. These variants exerted significantly enhanced in vitrotranscriptional activity, including increased stimulation of the PTH promoter. CONCLUSIONS We provide evidence that two novel GCM2 R67C inactivating mutations with an inability to bind DNA are causative of hypoparathyroidism. Additionally, we provide evidence that two novel GCM2 variants increased transactivation of the PTH promoter in vitro and are associated with FIHP. Furthermore, our studies suggest that activating GCM2 variants may contribute to facilitating more aggressive parathyroid disease.
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Affiliation(s)
- Lucie Canaff
- Metabolic Complications and Disorders, Research Institute-McGill University Health Centre, Montreal, Quebec, Canada
| | - Vito Guarnieri
- Division of Medical Genetics and Unit of Endocrinology, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Yoojung Kim
- Metabolic Complications and Disorders, Research Institute-McGill University Health Centre, Montreal, Quebec, Canada
| | - Betty Y L Wong
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Alexis Nolin-Lapalme
- Metabolic Complications and Disorders, Research Institute-McGill University Health Centre, Montreal, Quebec, Canada
| | - David E C Cole
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Salvatore Minisola
- Department of Internal Medicine and Medical Disciplines, ‘Sapienza’ Rome University, Rome, Italy
| | - Cristina Eller-Vainicher
- Department of Medical Sciences and Community, Fondazione Ca’Granda IRCCS Ospedale Maggiore Policlinico, Milan, Italy
| | | | - Andrea Repaci
- Unit of Endocrinology, S. Orsola Malpighi Hospital, Bologna, Italy
| | - Daniela Turchetti
- Center for the Studies of Hereditary Cancers, Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy
| | - Sabrina Corbetta
- Endocrinology and Diabetology Service, IRCCS Istituto Ortopedico Galeazzi, Milan, Italy
- Department of Biomedical, Surgical and Dental Sciences, University of Milan, Milan, Italy
| | - Alfredo Scillitani
- Division of Medical Genetics and Unit of Endocrinology, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - David Goltzman
- Metabolic Complications and Disorders, Research Institute-McGill University Health Centre, Montreal, Quebec, Canada
- Correspondence should be addressed to D Goltzman;
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10
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Singh P, Bhadada SK, Dahiya D, Saikia UN, Arya AK, Sachdeva N, Kaur J, Behera A, Brandi ML, Rao SD. GCM2 Silencing in Parathyroid Adenoma Is Associated With Promoter Hypermethylation and Gain of Methylation on Histone 3. J Clin Endocrinol Metab 2021; 106:e4084-e4096. [PMID: 34077544 PMCID: PMC8475237 DOI: 10.1210/clinem/dgab374] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Indexed: 02/06/2023]
Abstract
CONTEXT Glial cells missing 2 (GCM2), a zinc finger-transcription factor, is essentially required for the development of the parathyroid glands. OBJECTIVE We sought to identify whether the epigenetic alterations in GCM2 transcription are involved in the pathogenesis of sporadic parathyroid adenoma. In addition, we examined the association between promoter methylation and histone modifications with disease indices. METHODS Messenger RNA (mRNA) and protein expression of GCM2 were analyzed by reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) and immunohistochemistry in 33 adenomatous and 10 control parathyroid tissues. DNA methylation and histone methylation/acetylation of the GCM2 promoter were measured by bisulfite sequencing and chromatin immunoprecipitation-qPCR. Additionally, we investigated the role of epigenetic modifications on GCM2 and DNA methyltransferase 1 (DNMT1) expression in parathyroid (PTH)-C1 cells by treating with 5-aza-2'-deoxycytidine (DAC) and BRD4770 and assessed for GCM2 mRNA and DNMT1 protein levels. RESULTS mRNA and protein expression of GCM2 were lower in sporadic adenomatous than in control parathyroid tissues. This reduction correlated with hypermethylation (P < .001) and higher H3K9me3 levels in the GCM2 promoter (P < .04) in adenomas. In PTH-C1 cells, DAC treatment resulted in increased GCM2 transcription and decreased DNMT1 protein expression, while cells treated with the BRD4770 showed reduced H3K9me3 levels but a nonsignificant change in GCM2 transcription. CONCLUSION These findings suggest the concurrent association of promoter hypermethylation and higher H3K9me3 with the repression of GCM2 expression in parathyroid adenomas. Treatment with DAC restored GCM2 expression in PTH-C1 cells. Our results showed a possible epigenetic landscape in the tumorigenesis of parathyroid adenoma and also that DAC may be a promising avenue of research for parathyroid adenoma therapeutics.
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Affiliation(s)
- Priyanka Singh
- Department of Endocrinology, Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh, 160012, India
| | - Sanjay Kumar Bhadada
- Department of Endocrinology, Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh, 160012, India
- Correspondence: Sanjay Kumar Bhadada, MD, DM, Department of Endocrinology, Post Graduate Institute of Medical Education and Research, Chandigarh 160012, India.
| | - Divya Dahiya
- Department of General Surgery, PGIMER, Chandigarh, 160012, India
| | | | - Ashutosh Kumar Arya
- Department of Endocrinology, Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh, 160012, India
| | - Naresh Sachdeva
- Department of Endocrinology, Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh, 160012, India
| | - Jyotdeep Kaur
- Department of Biochemistry, PGIMER, Chandigarh, 160012, India
| | - Arunanshu Behera
- Department of General Surgery, PGIMER, Chandigarh, 160012, India
| | - Maria Luisa Brandi
- Department of Experimental and Clinical Biomedical Sciences, University of Florence, Florence 50121, Italy
| | - Sudhaker Dhanwada Rao
- Bone and Mineral Research Laboratory, Henry Ford Hospital, Detroit, Michigan 48202, USA
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11
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Abstract
Regulation of the serum calcium level in humans is achieved by the endocrine action of parathyroid glands working in concert with vitamin D and a set of critical target cells and tissues including osteoblasts, osteoclasts, the renal tubules, and the small intestine. The parathyroid glands, small highly vascularized endocrine organs located behind the thyroid gland, secrete parathyroid hormone (PTH) into the systemic circulation as is needed to keep the serum free calcium concentration within a tight physiologic range. Primary hyperparathyroidism (HPT), a disorder of mineral metabolism usually associated with abnormally elevated serum calcium, results from the uncontrolled release of PTH from one or several abnormal parathyroid glands. Although in the vast majority of cases HPT is a sporadic disease, it can also present as a manifestation of a familial syndrome. Many benign and malignant sporadic parathyroid neoplasms are caused by loss-of-function mutations in tumor suppressor genes that were initially identified by the study of genomic DNA from patients who developed HPT as a manifestation of an inherited syndrome. Somatic and inherited mutations in certain proto-oncogenes can also result in the development of parathyroid tumors. The clinical and genetic investigation of familial HPT in kindreds found to lack germline variants in the already known HPT-predisposition genes represents a promising future direction for the discovery of novel genes relevant to parathyroid tumor development.
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Affiliation(s)
- Jenny E. Blau
- Early Clinical Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD, United States
- Metabolic Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
| | - William F. Simonds
- Metabolic Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
- *Correspondence: William F. Simonds,
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12
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Abstract
Calcium homeostasis is maintained by the actions of the parathyroid glands, which release parathyroid hormone into the systemic circulation as necessary to maintain the serum calcium concentration within a tight physiologic range. Excessive secretion of parathyroid hormone from one or more neoplastic parathyroid glands, however, causes the metabolic disease primary hyperparathyroidism (HPT) typically associated with hypercalcemia. Although the majority of cases of HPT are sporadic, it can present in the context of a familial syndrome. Mutations in the tumor suppressor genes discovered by the study of such families are now recognized to be pathogenic for many sporadic parathyroid tumors. Inherited and somatic mutations of proto-oncogenes causing parathyroid neoplasia are also known. Future investigation of somatic changes in parathyroid tumor DNA and the study of kindreds with HPT yet lacking germline mutation in the set of genes known to predispose to HPT represent two avenues likely to unmask additional novel genes relevant to parathyroid neoplasia.
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Affiliation(s)
- William F Simonds
- Metabolic Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA
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13
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Egstrand S, Nordholm A, Morevati M, Mace ML, Hassan A, Naveh-Many T, Rukov JL, Gravesen E, Olgaard K, Lewin E. A molecular circadian clock operates in the parathyroid gland and is disturbed in chronic kidney disease associated bone and mineral disorder. Kidney Int 2020; 98:1461-1475. [PMID: 32721445 DOI: 10.1016/j.kint.2020.06.034] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Revised: 06/17/2020] [Accepted: 06/18/2020] [Indexed: 01/16/2023]
Abstract
Circadian rhythms in metabolism, hormone secretion, cell cycle and locomotor activity are regulated by a molecular circadian clock with the master clock in the suprachiasmatic nucleus of the central nervous system. However, an internal clock is also expressed in several peripheral tissues. Although about 10% of all genes are regulated by clock machinery an internal molecular circadian clock in the parathyroid glands has not previously been investigated. Parathyroid hormone secretion exhibits a diurnal variation and parathyroid hormone gene promoter contains an E-box like element, a known target of circadian clock proteins. Therefore, we examined whether an internal molecular circadian clock is operating in parathyroid glands, whether it is entrained by feeding and how it responds to chronic kidney disease. As uremia is associated with extreme parathyroid growth and since disturbed circadian rhythm is related to abnormal growth, we examined the expression of parathyroid clock and clock-regulated cell cycle genes in parathyroid glands of normal and uremic rats. Circadian clock genes were found to be rhythmically expressed in normal parathyroid glands and this clock was minimally entrained by feeding. Diurnal regulation of parathyroid glands was next examined. Significant rhythmicity of fibroblast-growth-factor-receptor-1, MafB and Gata3 was found. In uremic rats, deregulation of circadian clock genes and the cell cycle regulators, Cyclin D1, c-Myc, Wee1 and p27, which are influenced by the circadian clock, was found in parathyroid glands as well as the aorta. Thus, a circadian clock operates in parathyroid glands and this clock and downstream cell cycle regulators are disturbed in uremia and may contribute to dysregulated parathyroid proliferation in secondary hyperparathyroidism.
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Affiliation(s)
- Søren Egstrand
- Nephrological Department, Herlev Hospital, University of Copenhagen, Copenhagen, Denmark; Nephrological Department, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Anders Nordholm
- Nephrological Department, Herlev Hospital, University of Copenhagen, Copenhagen, Denmark; Nephrological Department, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Marya Morevati
- Nephrological Department, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Maria L Mace
- Nephrological Department, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Alia Hassan
- Minerva Center for Calcium and Bone Metabolism, Nephrology Services, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - Tally Naveh-Many
- Minerva Center for Calcium and Bone Metabolism, Nephrology Services, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - Jakob L Rukov
- Nephrological Department, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Eva Gravesen
- Nephrological Department, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Klaus Olgaard
- Nephrological Department, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Ewa Lewin
- Nephrological Department, Herlev Hospital, University of Copenhagen, Copenhagen, Denmark; Nephrological Department, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.
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14
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Abstract
Parathyroid hormone is an essential regulator of extracellular calcium and phosphate. PTH enhances calcium reabsorption while inhibiting phosphate reabsorption in the kidneys, increases the synthesis of 1,25-dihydroxyvitamin D, which then increases gastrointestinal absorption of calcium, and increases bone resorption to increase calcium and phosphate. Parathyroid disease can be an isolated endocrine disorder or part of a complex syndrome. Genetic mutations can account for diseases of parathyroid gland formulation, dysregulation of parathyroid hormone synthesis or secretion, and destruction of the parathyroid glands. Over the years, a number of different options are available for the treatment of different types of parathyroid disease. Therapeutic options include surgical removal of hypersecreting parathyroid tissue, administration of parathyroid hormone, vitamin D, activated vitamin D, calcium, phosphate binders, calcium-sensing receptor, and vitamin D receptor activators to name a few. The accurate assessment of parathyroid hormone also provides essential biochemical information to properly diagnose parathyroid disease. Currently available immunoassays may overestimate or underestimate bioactive parathyroid hormone because of interferences from truncated parathyroid hormone fragments, phosphorylation of parathyroid hormone, and oxidation of amino acids of parathyroid hormone.
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Affiliation(s)
- Edward Ki Yun Leung
- Department of Pathology and Laboratory Medicine, Children's Hospital Los Angeles, Los Angeles, CA, United States; Department of Pathology, Keck School of Medicine of University of Southern California, Los Angeles, CA, United States.
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15
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Leach K, Hannan FM, Josephs TM, Keller AN, Møller TC, Ward DT, Kallay E, Mason RS, Thakker RV, Riccardi D, Conigrave AD, Bräuner-Osborne H. International Union of Basic and Clinical Pharmacology. CVIII. Calcium-Sensing Receptor Nomenclature, Pharmacology, and Function. Pharmacol Rev 2020; 72:558-604. [PMID: 32467152 PMCID: PMC7116503 DOI: 10.1124/pr.119.018531] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The calcium-sensing receptor (CaSR) is a class C G protein-coupled receptor that responds to multiple endogenous agonists and allosteric modulators, including divalent and trivalent cations, L-amino acids, γ-glutamyl peptides, polyamines, polycationic peptides, and protons. The CaSR plays a critical role in extracellular calcium (Ca2+ o) homeostasis, as demonstrated by the many naturally occurring mutations in the CaSR or its signaling partners that cause Ca2+ o homeostasis disorders. However, CaSR tissue expression in mammals is broad and includes tissues unrelated to Ca2+ o homeostasis, in which it, for example, regulates the secretion of digestive hormones, airway constriction, cardiovascular effects, cellular differentiation, and proliferation. Thus, although the CaSR is targeted clinically by the positive allosteric modulators (PAMs) cinacalcet, evocalcet, and etelcalcetide in hyperparathyroidism, it is also a putative therapeutic target in diabetes, asthma, cardiovascular disease, and cancer. The CaSR is somewhat unique in possessing multiple ligand binding sites, including at least five putative sites for the "orthosteric" agonist Ca2+ o, an allosteric site for endogenous L-amino acids, two further allosteric sites for small molecules and the peptide PAM, etelcalcetide, and additional sites for other cations and anions. The CaSR is promiscuous in its G protein-coupling preferences, and signals via Gq/11, Gi/o, potentially G12/13, and even Gs in some cell types. Not surprisingly, the CaSR is subject to biased agonism, in which distinct ligands preferentially stimulate a subset of the CaSR's possible signaling responses, to the exclusion of others. The CaSR thus serves as a model receptor to study natural bias and allostery. SIGNIFICANCE STATEMENT: The calcium-sensing receptor (CaSR) is a complex G protein-coupled receptor that possesses multiple orthosteric and allosteric binding sites, is subject to biased signaling via several different G proteins, and has numerous (patho)physiological roles. Understanding the complexities of CaSR structure, function, and biology will aid future drug discovery efforts seeking to target this receptor for a diversity of diseases. This review summarizes what is known to date regarding key structural, pharmacological, and physiological features of the CaSR.
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Affiliation(s)
- Katie Leach
- Drug Discovery Biology, Monash Institute of Pharmaceutical Science, Monash University, Parkville, Australia (K.L., T.M.J., A.N.K.); Nuffield Department of Women's & Reproductive Health (F.M.H.) and Academic Endocrine Unit, Radcliffe Department of Clinical Medicine (F.M.H., R.V.T.), University of Oxford, Oxford, United Kingdom; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark (T.C.M., H.B.-O.); Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom (D.T.W.); Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria (E.K.); Physiology, School of Medical Sciences and Bosch Institute (R.S.M.) and School of Life & Environmental Sciences, Charles Perkins Centre (A.D.C.), University of Sydney, Sydney, Australia; and School of Biosciences, Cardiff University, Cardiff, United Kingdom (D.R.)
| | - Fadil M Hannan
- Drug Discovery Biology, Monash Institute of Pharmaceutical Science, Monash University, Parkville, Australia (K.L., T.M.J., A.N.K.); Nuffield Department of Women's & Reproductive Health (F.M.H.) and Academic Endocrine Unit, Radcliffe Department of Clinical Medicine (F.M.H., R.V.T.), University of Oxford, Oxford, United Kingdom; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark (T.C.M., H.B.-O.); Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom (D.T.W.); Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria (E.K.); Physiology, School of Medical Sciences and Bosch Institute (R.S.M.) and School of Life & Environmental Sciences, Charles Perkins Centre (A.D.C.), University of Sydney, Sydney, Australia; and School of Biosciences, Cardiff University, Cardiff, United Kingdom (D.R.)
| | - Tracy M Josephs
- Drug Discovery Biology, Monash Institute of Pharmaceutical Science, Monash University, Parkville, Australia (K.L., T.M.J., A.N.K.); Nuffield Department of Women's & Reproductive Health (F.M.H.) and Academic Endocrine Unit, Radcliffe Department of Clinical Medicine (F.M.H., R.V.T.), University of Oxford, Oxford, United Kingdom; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark (T.C.M., H.B.-O.); Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom (D.T.W.); Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria (E.K.); Physiology, School of Medical Sciences and Bosch Institute (R.S.M.) and School of Life & Environmental Sciences, Charles Perkins Centre (A.D.C.), University of Sydney, Sydney, Australia; and School of Biosciences, Cardiff University, Cardiff, United Kingdom (D.R.)
| | - Andrew N Keller
- Drug Discovery Biology, Monash Institute of Pharmaceutical Science, Monash University, Parkville, Australia (K.L., T.M.J., A.N.K.); Nuffield Department of Women's & Reproductive Health (F.M.H.) and Academic Endocrine Unit, Radcliffe Department of Clinical Medicine (F.M.H., R.V.T.), University of Oxford, Oxford, United Kingdom; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark (T.C.M., H.B.-O.); Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom (D.T.W.); Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria (E.K.); Physiology, School of Medical Sciences and Bosch Institute (R.S.M.) and School of Life & Environmental Sciences, Charles Perkins Centre (A.D.C.), University of Sydney, Sydney, Australia; and School of Biosciences, Cardiff University, Cardiff, United Kingdom (D.R.)
| | - Thor C Møller
- Drug Discovery Biology, Monash Institute of Pharmaceutical Science, Monash University, Parkville, Australia (K.L., T.M.J., A.N.K.); Nuffield Department of Women's & Reproductive Health (F.M.H.) and Academic Endocrine Unit, Radcliffe Department of Clinical Medicine (F.M.H., R.V.T.), University of Oxford, Oxford, United Kingdom; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark (T.C.M., H.B.-O.); Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom (D.T.W.); Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria (E.K.); Physiology, School of Medical Sciences and Bosch Institute (R.S.M.) and School of Life & Environmental Sciences, Charles Perkins Centre (A.D.C.), University of Sydney, Sydney, Australia; and School of Biosciences, Cardiff University, Cardiff, United Kingdom (D.R.)
| | - Donald T Ward
- Drug Discovery Biology, Monash Institute of Pharmaceutical Science, Monash University, Parkville, Australia (K.L., T.M.J., A.N.K.); Nuffield Department of Women's & Reproductive Health (F.M.H.) and Academic Endocrine Unit, Radcliffe Department of Clinical Medicine (F.M.H., R.V.T.), University of Oxford, Oxford, United Kingdom; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark (T.C.M., H.B.-O.); Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom (D.T.W.); Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria (E.K.); Physiology, School of Medical Sciences and Bosch Institute (R.S.M.) and School of Life & Environmental Sciences, Charles Perkins Centre (A.D.C.), University of Sydney, Sydney, Australia; and School of Biosciences, Cardiff University, Cardiff, United Kingdom (D.R.)
| | - Enikö Kallay
- Drug Discovery Biology, Monash Institute of Pharmaceutical Science, Monash University, Parkville, Australia (K.L., T.M.J., A.N.K.); Nuffield Department of Women's & Reproductive Health (F.M.H.) and Academic Endocrine Unit, Radcliffe Department of Clinical Medicine (F.M.H., R.V.T.), University of Oxford, Oxford, United Kingdom; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark (T.C.M., H.B.-O.); Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom (D.T.W.); Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria (E.K.); Physiology, School of Medical Sciences and Bosch Institute (R.S.M.) and School of Life & Environmental Sciences, Charles Perkins Centre (A.D.C.), University of Sydney, Sydney, Australia; and School of Biosciences, Cardiff University, Cardiff, United Kingdom (D.R.)
| | - Rebecca S Mason
- Drug Discovery Biology, Monash Institute of Pharmaceutical Science, Monash University, Parkville, Australia (K.L., T.M.J., A.N.K.); Nuffield Department of Women's & Reproductive Health (F.M.H.) and Academic Endocrine Unit, Radcliffe Department of Clinical Medicine (F.M.H., R.V.T.), University of Oxford, Oxford, United Kingdom; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark (T.C.M., H.B.-O.); Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom (D.T.W.); Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria (E.K.); Physiology, School of Medical Sciences and Bosch Institute (R.S.M.) and School of Life & Environmental Sciences, Charles Perkins Centre (A.D.C.), University of Sydney, Sydney, Australia; and School of Biosciences, Cardiff University, Cardiff, United Kingdom (D.R.)
| | - Rajesh V Thakker
- Drug Discovery Biology, Monash Institute of Pharmaceutical Science, Monash University, Parkville, Australia (K.L., T.M.J., A.N.K.); Nuffield Department of Women's & Reproductive Health (F.M.H.) and Academic Endocrine Unit, Radcliffe Department of Clinical Medicine (F.M.H., R.V.T.), University of Oxford, Oxford, United Kingdom; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark (T.C.M., H.B.-O.); Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom (D.T.W.); Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria (E.K.); Physiology, School of Medical Sciences and Bosch Institute (R.S.M.) and School of Life & Environmental Sciences, Charles Perkins Centre (A.D.C.), University of Sydney, Sydney, Australia; and School of Biosciences, Cardiff University, Cardiff, United Kingdom (D.R.)
| | - Daniela Riccardi
- Drug Discovery Biology, Monash Institute of Pharmaceutical Science, Monash University, Parkville, Australia (K.L., T.M.J., A.N.K.); Nuffield Department of Women's & Reproductive Health (F.M.H.) and Academic Endocrine Unit, Radcliffe Department of Clinical Medicine (F.M.H., R.V.T.), University of Oxford, Oxford, United Kingdom; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark (T.C.M., H.B.-O.); Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom (D.T.W.); Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria (E.K.); Physiology, School of Medical Sciences and Bosch Institute (R.S.M.) and School of Life & Environmental Sciences, Charles Perkins Centre (A.D.C.), University of Sydney, Sydney, Australia; and School of Biosciences, Cardiff University, Cardiff, United Kingdom (D.R.)
| | - Arthur D Conigrave
- Drug Discovery Biology, Monash Institute of Pharmaceutical Science, Monash University, Parkville, Australia (K.L., T.M.J., A.N.K.); Nuffield Department of Women's & Reproductive Health (F.M.H.) and Academic Endocrine Unit, Radcliffe Department of Clinical Medicine (F.M.H., R.V.T.), University of Oxford, Oxford, United Kingdom; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark (T.C.M., H.B.-O.); Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom (D.T.W.); Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria (E.K.); Physiology, School of Medical Sciences and Bosch Institute (R.S.M.) and School of Life & Environmental Sciences, Charles Perkins Centre (A.D.C.), University of Sydney, Sydney, Australia; and School of Biosciences, Cardiff University, Cardiff, United Kingdom (D.R.)
| | - Hans Bräuner-Osborne
- Drug Discovery Biology, Monash Institute of Pharmaceutical Science, Monash University, Parkville, Australia (K.L., T.M.J., A.N.K.); Nuffield Department of Women's & Reproductive Health (F.M.H.) and Academic Endocrine Unit, Radcliffe Department of Clinical Medicine (F.M.H., R.V.T.), University of Oxford, Oxford, United Kingdom; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark (T.C.M., H.B.-O.); Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom (D.T.W.); Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria (E.K.); Physiology, School of Medical Sciences and Bosch Institute (R.S.M.) and School of Life & Environmental Sciences, Charles Perkins Centre (A.D.C.), University of Sydney, Sydney, Australia; and School of Biosciences, Cardiff University, Cardiff, United Kingdom (D.R.)
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16
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Uchiyama T, Ohkido I, Nakashima A, Saito Y, Okabe M, Yokoo T. Severe chronic kidney disease environment reduced calcium-sensing receptor expression in parathyroid glands of adenine-induced rats even without high phosphorus diet. BMC Nephrol 2020; 21:219. [PMID: 32517664 PMCID: PMC7285719 DOI: 10.1186/s12882-020-01880-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 06/02/2020] [Indexed: 02/08/2023] Open
Abstract
Background Chronic kidney disease (CKD) disrupts mineral homeostasis and its main underlying cause is secondary hyperparathyroidism (SHPT). We previously reported that calcium-sensing receptor (CaSR) mRNA and protein expression in parathyroid glands (PTGs) significantly decreased in a CKD rat model induced by a 5/6 nephrectomy that were fed a high phosphorus diet. However, there was a significant difference in the severity of CKD between high phosphorus and adequate phosphorus diet groups. Thus, it was unclear whether CKD environment or the high phosphorus diet influenced CaSR expression, and the underlying mechanism remains largely unknown. Methods CKD was induced in rats with 0.75% adenine-containing diet. CKD and control rats were maintained for 5 days and 2 weeks on diets with 0.7% or 1.3% phosphorus. For gene expression analysis, quantitative real-time polymerase chain reaction was performed with TaqMan probes. Protein expression was analyzed by immunohistochemistry. Results PTG CaSR expression significantly decreased in the presence of a severe CKD environment, even without the high phosphate load. Ki67 expressing cells in PTGs were significantly higher only in the CKD rats fed a high phosphorus diet. Furthermore, among the many genes that could affect CaSR expression, only vitamin D receptor (VDR) and glial cells missing 2 (Gcm2) showed significant changes. Moreover, Gcm2 was significantly reduced at an early stage without significant changes in serum calcium, phosphorus and 1,25(OH)2 vitamin D, and there was no significant reduction in CaSR and VDR expressions. Then, significantly elevated Ki67-positive cell numbers were also only observed in the early CKD PTGs with high-phosphorus diets. Conclusions Our data suggest that the cause of the decreased PTG CaSR expression is the reduction in VDR and Gcm2 expression; Gcm2 may play a role in the onset and progression of SHPT.
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Affiliation(s)
- Taketo Uchiyama
- Division of Nephrology and Hypertension, Department of Internal Medicine, the Jikei University School of Medicine, Tokyo, Japan
| | - Ichiro Ohkido
- Division of Nephrology and Hypertension, Department of Internal Medicine, the Jikei University School of Medicine, Tokyo, Japan.
| | - Akio Nakashima
- Division of Nephrology and Hypertension, Department of Internal Medicine, the Jikei University School of Medicine, Tokyo, Japan
| | - Yatsumu Saito
- Division of Nephrology and Hypertension, Department of Internal Medicine, the Jikei University School of Medicine, Tokyo, Japan
| | - Masataka Okabe
- Department of Anatomy, the Jikei University School of Medicine, Tokyo, Japan
| | - Takashi Yokoo
- Division of Nephrology and Hypertension, Department of Internal Medicine, the Jikei University School of Medicine, Tokyo, Japan
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17
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Verdelli C, Tavanti GS, Corbetta S. Intratumor heterogeneity in human parathyroid tumors. Histol Histopathol 2020; 35:1213-1228. [PMID: 32468569 DOI: 10.14670/hh-18-230] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Parathyroid tumors are the second most common endocrine neoplasia after thyroid neoplasia. They are mostly associated with impaired parathormone (PTH) synthesis and release determining the metabolic and clinical condition of primary hyperparathyroidism (PHPT). PHPT is the third most prevalent endocrine disorder, mainly affecting postmenopausal women. Parathyroid benign tumors, both adenomas of a single gland or hyperplasia involving all the glands, are the main histotypes, occurring in more than 95% of PHPT cases. The differential diagnosis between benign and malignant parathyroid lesions is a challenge for clinicians. It relies on histologic features, which display significant overlap between the histotypes with different clinical outcomes. Parathyroid adenomas and hyperplasia have been considered so far as a unique monoclonal/polyclonal entity, while accumulating evidence suggest great heterogeneity. Intratumor parathyroid heterogeneity involves tumor cell type, as well as tumor cell function, in terms of PTH synthesis and secretion, and of expression patterns of membrane and nuclear receptors (calcium sensing receptor, vitamin D receptor, α-klotho receptor and others). Intratumor heterogeneity can also interfere with cell molecular biology, in regard to clonality, oncosuppressor gene expression (such as MEN1 and HRPT2/CDC73), transcription factors (GCM2, TBX1) and microRNA expression. Such heterogeneity is likely involved in the phenotypic variability of the parathyroid tumors, and it should be considered in the clinical management, though at present target therapies are not available, with the exception of the calcium sensing receptor agonists.
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Affiliation(s)
- C Verdelli
- Laboratory of Experimental Endocrinology, IRCCS Istituto Ortopedico Galeazzi, Milan, Italy
| | - G S Tavanti
- Laboratory of Experimental Endocrinology, IRCCS Istituto Ortopedico Galeazzi, Milan, Italy
| | - S Corbetta
- Endocrinology and Diabetology Service, IRCCS Istituto Ortopedico Galeazzi, Milan, Italy.,Department of Biomedical, Surgical and Dental Sciences, University of Milan, Milan, Italy.
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18
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Fabbri S, Zonefrati R, Galli G, Gronchi G, Perigli G, Borrelli A, Brandi ML. In Vitro Control of Genes Critical for Parathyroid Embryogenesis by Extracellular Calcium. J Endocr Soc 2020; 4:bvaa058. [PMID: 32666007 PMCID: PMC7326476 DOI: 10.1210/jendso/bvaa058] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 05/22/2020] [Indexed: 02/07/2023] Open
Abstract
Background The expression of the parathyroid transcription factors, encoded by the genes GATA3, GCM2, and MAFB, persists after parathyroid morphogenesis. This suggests a role of these genes in the regulatory program that governs parathyroid function in the adult. Indeed, these 3 genes form a transcriptional cascade able to activate PTH gene expression. Materials and Methods Adult adenoma parathyroid tissues were put in primary cell culture to evaluate the messenger ribonucleic acid (mRNA) expression of the PTH gene, of the genes involved in the calcium regulatory signaling pathway (CaSR, GNA11, and AP2S1), and of the 3 genes (GATA3, GCM2, and MAFB) involved in the parathyroid morphogenesis in the presence of different extracellular calcium concentrations from 0.1 mM to 3.0 mM. Aim The aim of the study was to investigate whether different extracellular calcium conditions could control the expression of transcription factors critical for parathyroid embryogenesis. Results The results of the experiments showed that the mRNA expression of GATA3, GCM2, and MAFB genes follows the same response as the PTH gene to extracellular calcium concentrations, with the highest expression at low calcium (0.1 mM) and the lowest at high calcium (3.0 mM). Conversely, the genes involved in the calcium signaling in the parathyroid cells showed a variable response to the extracellular calcium concentrations, with the CaSR and GNA11 genes exhibiting a sensitivity to low calcium concentrations. Conclusions These findings indicate that transcription factors recognized for their role in parathyroid embryogenesis show a response to extracellular calcium later in adulthood that parallels the behavior of the PTH gene.
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Affiliation(s)
- Sergio Fabbri
- Department of Experimental and Clinical Biomedical Sciences, University of Florence, Florence, Italy
| | - Roberto Zonefrati
- Department of Experimental and Clinical Biomedical Sciences, University of Florence, Florence, Italy
| | - Gianna Galli
- Department of Experimental and Clinical Biomedical Sciences, University of Florence, Florence, Italy
| | - Giorgio Gronchi
- Department of Neuroscience, Psychology, Drug Research & Child Health, University of Florence, Florence, Italy
| | - Giuliano Perigli
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Andrea Borrelli
- Bariatric, General Surgery and Metabolic Department, Santa Maria Nuova Hospital, Florence, Italy
| | - Maria Luisa Brandi
- Department of Experimental and Clinical Biomedical Sciences, University of Florence, Florence, Italy
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19
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Yamada T, Tatsumi N, Anraku A, Suzuki H, Kamejima S, Uchiyama T, Ohkido I, Yokoo T, Okabe M. Gcm2 regulates the maintenance of parathyroid cells in adult mice. PLoS One 2019; 14:e0210662. [PMID: 30677043 PMCID: PMC6345461 DOI: 10.1371/journal.pone.0210662] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 12/28/2018] [Indexed: 01/24/2023] Open
Abstract
Glial cells missing homolog 2 (GCM2), a zinc finger-type transcription factor, is essential for the development of parathyroid glands. It is considered to be a master regulator because the glands do not form when Gcm2 is deficient. Remarkably, Gcm2 expression is maintained throughout the fetal stage and after birth. Considering the Gcm2 function in embryonic stages, it is predicted that Gcm2 maintains parathyroid cell differentiation and survival in adults. However, there is a lack of research regarding the function of Gcm2 in adulthood. Therefore, we analyzed Gcm2 function in adult tamoxifen-inducible Gcm2 conditional knockout mice. One month after tamoxifen injection, Gcm2-knockout mice showed no significant difference in serum calcium, phosphate, and PTH levels and in the expressions of calcium-sensing receptor (Casr) and parathyroid hormone (Pth), whereas Ki-67 positive cells were decreased and terminal deoxynucleotidyl transferase (TdT) dUTP Nick-End Labeling (TUNEL) positive cell number did not change, as compared with those of controls. Seven months after tamoxifen injection, Gcm2-knockout mice showed shrinkage of the parathyroid glands and fewer parathyroid cells. A significant decrease was noted in Casr- and Pth-expressing cells and serum PTH and Ca levels, whereas serum phosphate levels increased, as compared with those of controls. All our results concluded that a reduction of Gcm2 expression leads to a reduction of parathyroid cell proliferation, an increase in cell death, and an attenuation of parathyroid function. Therefore, we indicate that Gcm2 plays a prominent role in adult parathyroid cell proliferation and maintenance.
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Affiliation(s)
- Taku Yamada
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
- Department of Anatomy, The Jikei University School of Medicine, Tokyo, Japan
| | - Norifumi Tatsumi
- Department of Anatomy, The Jikei University School of Medicine, Tokyo, Japan
| | - Akane Anraku
- Department of Anatomy, The Jikei University School of Medicine, Tokyo, Japan
| | - Hideaki Suzuki
- Department of Anatomy, The Jikei University School of Medicine, Tokyo, Japan
| | - Sahoko Kamejima
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
- Department of Anatomy, The Jikei University School of Medicine, Tokyo, Japan
| | - Taketo Uchiyama
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Ichiro Ohkido
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Takashi Yokoo
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Masataka Okabe
- Department of Anatomy, The Jikei University School of Medicine, Tokyo, Japan
- * E-mail:
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20
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Marx SJ, Goltzman D. Evolution of Our Understanding of the Hyperparathyroid Syndromes: A Historical Perspective. J Bone Miner Res 2019; 34:22-37. [PMID: 30536424 PMCID: PMC6396287 DOI: 10.1002/jbmr.3650] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 11/14/2018] [Accepted: 11/20/2018] [Indexed: 12/19/2022]
Abstract
We review advancing and overlapping stages for our understanding of the expressions of six hyperparathyroid (HPT) syndromes: multiple endocrine neoplasia type 1 (MEN1) or type 4, multiple endocrine neoplasia type 2A (MEN2A), hyperparathyroidism-jaw tumor syndrome, familial hypocalciuric hypercalcemia, neonatal severe primary hyperparathyroidism, and familial isolated hyperparathyroidism. During stage 1 (1903 to 1967), the introduction of robust measurement of serum calcium was a milestone that uncovered hypercalcemia as the first sign of dysfunction in many HPT subjects, and inheritability was reported in each syndrome. The earliest reports of HPT syndromes were biased toward severe or striking manifestations. During stage 2 (1959 to 1985), the early formulations of a syndrome were improved. Radioimmunoassays (parathyroid hormone [PTH], gastrin, insulin, prolactin, calcitonin) were breakthroughs. They could identify a syndrome carrier, indicate an emerging tumor, characterize a tumor, or monitor a tumor. During stage 3 (1981 to 2006), the assembly of many cases enabled recognition of further details. For example, hormone non-secreting skin lesions were discovered in MEN1 and MEN2A. During stage 4 (1985 to the present), new genomic tools were a revolution for gene identification. Four principal genes ("principal" implies mutated or deleted in 50% or more probands for its syndrome) (MEN1, RET, CASR, CDC73) were identified for five syndromes. During stage 5 (1993 to the present), seven syndromal genes other than a principal gene were identified (CDKN1B, CDKN2B, CDKN2C, CDKN1A, GNA11, AP2S1, GCM2). Identification of AP2S1 and GCM2 became possible because of whole-exome sequencing. During stages 4 and 5, the newly identified genes enabled many studies, including robust assignment of the carriers and non-carriers of a mutation. Furthermore, molecular pathways of RET and the calcium-sensing receptor were elaborated, thereby facilitating developments in pharmacotherapy. Current findings hold the promise that more genes for HPT syndromes will be identified and studied in the near future. © 2018 American Society for Bone and Mineral Research.
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Affiliation(s)
- Stephen J Marx
- Office of the Scientific Director, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - David Goltzman
- Calcium Research Laboratory, Metabolic Disorders and Complications Program, Research Institute of the McGill University Health Centre, Montreal, Canada
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21
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Cinque L, Pugliese F, Salcuni AS, Scillitani A, Guarnieri V. Molecular pathogenesis of parathyroid tumours. Best Pract Res Clin Endocrinol Metab 2018; 32:891-908. [PMID: 30477753 DOI: 10.1016/j.beem.2018.11.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Parathyroid tumors represent an elusive endocrine neoplasia, which lead to primary hyperparathyroidism, pHPT, a common endocrine calcium disorder characterized by hypercalcemia and normal-high parathormone secretion. Parathyroid tumours are benign adenomas or multiple glands hyperplasia in the vast majority (>99% of cases), while malignant neoplasms are rare (less than 1%). Despite pHPT is a common disorder, our knowledge about the genetic predisposition and molecular pathophysiology is limited to the familial syndromic forms of parathyroid tumour, that, however, represent not more than the 10% of all the cases; instead, the pathophysiology of sporadic forms remains an open field, although data about epigenetic mechanisms or private genes have been supposed. Here we present an overview of more recent acquisitions about the genetic causes along with their molecular mechanisms of benign, but also, malignant parathyroid tumours either in sporadic and familial presentation.
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Affiliation(s)
- Luigia Cinque
- Fondazione IRCCS Casa Sollievo della Sofferenza Hospital, Division of Medical Genetics, Italy.
| | - Flavia Pugliese
- Fondazione IRCCS Casa Sollievo della Sofferenza Hospital, Unit of Endocrinology, San Giovanni Rotondo, FG, Italy.
| | | | - Alfredo Scillitani
- Fondazione IRCCS Casa Sollievo della Sofferenza Hospital, Unit of Endocrinology, San Giovanni Rotondo, FG, Italy.
| | - Vito Guarnieri
- Fondazione IRCCS Casa Sollievo della Sofferenza Hospital, Division of Medical Genetics, Italy.
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22
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Abstract
Hypoparathyroidism is characterized by hypocalcemia and hyperphosphatemia and is due to insufficient levels of circulating parathyroid hormone. Hypoparathyroidism may be an isolated condition or a component of a complex syndrome. Although genetic disorders are not the most common cause of hypoparathyroidism, molecular analyses have identified a growing number of genes that when defective result in impaired formation of the parathyroid glands, disordered synthesis or secretion of parathyroid hormone, or postnatal destruction of the parathyroid glands.
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Affiliation(s)
- Rebecca J Gordon
- Division of Endocrinology and Diabetes, The Center for Bone Health, The Children's Hospital of Philadelphia, Department of Pediatrics, University of Pennsylvania Perelman School of Medicine, 11 Northwest Tower, Suite 30, 3401 Civic Center Boulevard, Philadelphia, PA 19104, USA.
| | - Michael A Levine
- Division of Endocrinology and Diabetes, The Center for Bone Health, The Children's Hospital of Philadelphia, Department of Pediatrics, University of Pennsylvania Perelman School of Medicine, 3615 Civic Center Boulevard, Abramson Research Building, Room 510A, Philadelphia, PA 19104, USA
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23
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Vaira V, Verdelli C, Forno I, Corbetta S. MicroRNAs in parathyroid physiopathology. Mol Cell Endocrinol 2017; 456:9-15. [PMID: 27816765 DOI: 10.1016/j.mce.2016.10.035] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 10/30/2016] [Accepted: 10/31/2016] [Indexed: 12/19/2022]
Abstract
Parathyroid glands regulate calcium homeostasis through synthesis and secretion of parathormone (PTH). They sense the extracellular calcium concentration through the G-protein coupled calcium sensing receptor (CASR) and release PTH in order to preserve calcium concentration in the physiological range. Tumors of the parathyroid glands are common endocrine neoplasia associated with primary or secondary/tertiary hyperparathyroidisms. Small non-coding RNAs are regulators of gene expression able to modulate hormone synthesis, hormone release and endocrine cell proliferation. In this scenario, microRNA (miRNA) expression profiles have been investigated in parathyroid tumors, while miRNAs are involved in hypocalcemia and uremia-induced PTH release from normal parathyroid cells. Here we reviewed data about the role of miRNAs in the regulation of: 1) PTH synthesis and secretion; 2) CASR expression; 3) parathyroid cell tumorigenesis. Though studies about miRNAs in parathyroid gland pathophysiology are limited, they contribute in elucidating regulatory pathways involved in PTH release and parathyroid cell tumorigenesis.
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Affiliation(s)
- V Vaira
- Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy; Division of Pathology, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - C Verdelli
- Laboratory of Experimental Endocrinology, IRCCS Istituto Ortopedico Galeazzi, Milan, Italy
| | - I Forno
- Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy; Division of Pathology, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - S Corbetta
- Endocrinology Service, Department of Biomedical Sciences for Health, University of Milan, IRCCS Istituto Ortopedico Galeazzi, Milan, Italy.
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24
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Cinque L, Sparaneo A, Penta L, Mencarelli A, Rogaia D, Esposito S, Fabrizio FP, Baorda F, Verrotti A, Falorni A, Stangoni G, Hendy GN, Guarnieri V, Prontera P. Autosomal Dominant PTH Gene Signal Sequence Mutation in a Family With Familial Isolated Hypoparathyroidism. J Clin Endocrinol Metab 2017; 102:3961-3969. [PMID: 28938448 DOI: 10.1210/jc.2017-00250] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Accepted: 08/15/2017] [Indexed: 02/13/2023]
Abstract
CONTEXT Familial isolated hypoparathyroidism (FIH) is a genetically heterogeneous disorder due to mutations of the calcium-sensing receptor (CASR), glial cells missing-2 (GCM2), guanine nucleotide binding protein α11 (GNA11), or parathyroid hormone (PTH) genes. Thus far, only four cases with homozygous and two cases with heterozygous mutations in the PTH gene have been reported. OBJECTIVE To clinically describe an FIH family and identify and characterize the causal gene mutation. DESIGN Genomic DNA of the family members was subjected to CASR, GCM2, GNA11, and PTH gene mutational analysis. Functional assays were performed on the variant identified. PARTICIPANTS Six subjects of a three-generation FIH family with three affected individuals having severe hypocalcemia and inappropriately low serum PTH. RESULTS No mutations were detected in the CASR, GCM2, and GNA11 genes. A heterozygous variant that segregated with the disease was identified in PTH gene exon 2 (c.41T>A; p.M14K). This missense variant, in the hydrophobic core of the signal sequence, was predicted in silico to impair cleavage of preproPTH to proPTH. Functional assays in HEK293 cells demonstrated much greater retention intracellularly but impaired secretion into the medium of the M14K mutant relative to wild type. The addition of the pharmacological chaperone, 4-phenylbutyric acid, led to a reduction of cellular retention and increased accumulation in the cell medium of the M14K mutant. CONCLUSIONS We report a heterozygous PTH mutation in an FIH family and demonstrate accumulation of the mutant intracellularly and its impaired secretion. An accurate genetic diagnosis in such hypoparathyroid patients is critical for appropriate treatment and genetic counseling.
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Affiliation(s)
- Luigia Cinque
- Medical Genetics and Laboratory of Oncology, IRCCS Casa Sollievo della Sofferenza Hospital, San Giovanni Rotondo, Foggia 71013, Italy
| | - Angelo Sparaneo
- Medical Genetics and Laboratory of Oncology, IRCCS Casa Sollievo della Sofferenza Hospital, San Giovanni Rotondo, Foggia 71013, Italy
| | - Laura Penta
- Department of Pediatrics, University of Perugia, Perugia 06100, Italy
| | - Amedea Mencarelli
- Regional Reference Centre for Medical Genetics, "Santa Maria della Misericordia" Hospital, Perugia 06129, Italy
| | - Daniela Rogaia
- Regional Reference Centre for Medical Genetics, "Santa Maria della Misericordia" Hospital, Perugia 06129, Italy
| | - Susanna Esposito
- Department of Pediatrics, University of Perugia, Perugia 06100, Italy
| | - Federico Pio Fabrizio
- Medical Genetics and Laboratory of Oncology, IRCCS Casa Sollievo della Sofferenza Hospital, San Giovanni Rotondo, Foggia 71013, Italy
| | - Filomena Baorda
- Medical Genetics and Laboratory of Oncology, IRCCS Casa Sollievo della Sofferenza Hospital, San Giovanni Rotondo, Foggia 71013, Italy
| | - Alberto Verrotti
- Department of Paediatrics, University of L'Aquila, L'Aquila 67100, Italy
| | - Alberto Falorni
- Section of Internal Medicine and Endocrine and Metabolic Sciences, Department of Medicine, University of Perugia, Perugia 06100, Italy
| | - Gabriela Stangoni
- Regional Reference Centre for Medical Genetics, "Santa Maria della Misericordia" Hospital, Perugia 06129, Italy
| | - Geoffrey N Hendy
- Metabolic Disorders and Complications, McGill University Health Centre Research Institute, Montreal, Quebec H4A 3J1, Canada
- Department of Medicine, McGill University, Montreal, Quebec H4A 3J1, Canada
- Department of Physiology, McGill University, Montreal, Quebec H3G 1Y6, Canada
- Department of Human Genetics, McGill University, Montreal, Quebec H3A 0C7, Canada
| | - Vito Guarnieri
- Medical Genetics and Laboratory of Oncology, IRCCS Casa Sollievo della Sofferenza Hospital, San Giovanni Rotondo, Foggia 71013, Italy
| | - Paolo Prontera
- Regional Reference Centre for Medical Genetics, "Santa Maria della Misericordia" Hospital, Perugia 06129, Italy
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Xi X, Lu L, Zhuge CC, Chen X, Zhai Y, Cheng J, Mao H, Yang CC, Tan BCM, Lee YN, Chien CT, Ho MS. The hypoparathyroidism-associated mutation in Drosophila Gcm compromises protein stability and glial cell formation. Sci Rep 2017; 7:39856. [PMID: 28051179 PMCID: PMC5209662 DOI: 10.1038/srep39856] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 11/29/2016] [Indexed: 01/05/2023] Open
Abstract
Differentiated neurons and glia are acquired from immature precursors via transcriptional controls exerted by factors such as proteins in the family of Glial Cells Missing (Gcm). Mammalian Gcm proteins mediate neural stem cell induction, placenta and parathyroid development, whereas Drosophila Gcm proteins act as a key switch to determine neuronal and glial cell fates and regulate hemocyte development. The present study reports a hypoparathyroidism-associated mutation R59L that alters Drosophila Gcm (Gcm) protein stability, rendering it unstable, and hyperubiquitinated via the ubiquitin-proteasome system (UPS). GcmR59L interacts with the Slimb-based SCF complex and Protein Kinase C (PKC), which possibly plays a role in its phosphorylation, hence altering ubiquitination. Additionally, R59L causes reduced Gcm protein levels in a manner independent of the PEST domain signaling protein turnover. GcmR59L proteins bind DNA, functionally activate transcription, and induce glial cells, yet at a less efficient level. Finally, overexpression of either wild-type human Gcmb (hGcmb) or hGcmb carrying the conserved hypoparathyroidism mutation only slightly affects gliogenesis, indicating differential regulatory mechanisms in human and flies. Taken together, these findings demonstrate the significance of this disease-associated mutation in controlling Gcm protein stability via UPS, hence advance our understanding on how glial formation is regulated.
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Affiliation(s)
- Xiao Xi
- Research Center for Translational Medicine, Shanghai East Hospital, Tongji University School of Medicine, No. 150 Jimo Road, Shanghai 200120, China.,Key Laboratory of Arrhythmias of the Ministry of Education of China, Shanghai East Hospital, Tongji University School of Medicine, No. 150 Jimo Road, Shanghai 200120, China.,Department of Anatomy and Neurobiology, 1239 Siping Road, Tongji University School of Medicine, Shanghai, 200092, China
| | - Lu Lu
- Research Center for Translational Medicine, Shanghai East Hospital, Tongji University School of Medicine, No. 150 Jimo Road, Shanghai 200120, China.,Key Laboratory of Arrhythmias of the Ministry of Education of China, Shanghai East Hospital, Tongji University School of Medicine, No. 150 Jimo Road, Shanghai 200120, China.,Department of Anatomy and Neurobiology, 1239 Siping Road, Tongji University School of Medicine, Shanghai, 200092, China
| | - Chun-Chun Zhuge
- Research Center for Translational Medicine, Shanghai East Hospital, Tongji University School of Medicine, No. 150 Jimo Road, Shanghai 200120, China.,Key Laboratory of Arrhythmias of the Ministry of Education of China, Shanghai East Hospital, Tongji University School of Medicine, No. 150 Jimo Road, Shanghai 200120, China.,Department of Anatomy and Neurobiology, 1239 Siping Road, Tongji University School of Medicine, Shanghai, 200092, China
| | - Xuebing Chen
- Research Center for Translational Medicine, Shanghai East Hospital, Tongji University School of Medicine, No. 150 Jimo Road, Shanghai 200120, China.,Key Laboratory of Arrhythmias of the Ministry of Education of China, Shanghai East Hospital, Tongji University School of Medicine, No. 150 Jimo Road, Shanghai 200120, China.,Department of Anatomy and Neurobiology, 1239 Siping Road, Tongji University School of Medicine, Shanghai, 200092, China
| | - Yuanfen Zhai
- Research Center for Translational Medicine, Shanghai East Hospital, Tongji University School of Medicine, No. 150 Jimo Road, Shanghai 200120, China.,Key Laboratory of Arrhythmias of the Ministry of Education of China, Shanghai East Hospital, Tongji University School of Medicine, No. 150 Jimo Road, Shanghai 200120, China.,Department of Anatomy and Neurobiology, 1239 Siping Road, Tongji University School of Medicine, Shanghai, 200092, China
| | - Jingjing Cheng
- Research Center for Translational Medicine, Shanghai East Hospital, Tongji University School of Medicine, No. 150 Jimo Road, Shanghai 200120, China.,Key Laboratory of Arrhythmias of the Ministry of Education of China, Shanghai East Hospital, Tongji University School of Medicine, No. 150 Jimo Road, Shanghai 200120, China.,Department of Anatomy and Neurobiology, 1239 Siping Road, Tongji University School of Medicine, Shanghai, 200092, China
| | - Haian Mao
- Research Center for Translational Medicine, Shanghai East Hospital, Tongji University School of Medicine, No. 150 Jimo Road, Shanghai 200120, China.,Key Laboratory of Arrhythmias of the Ministry of Education of China, Shanghai East Hospital, Tongji University School of Medicine, No. 150 Jimo Road, Shanghai 200120, China.,Department of Anatomy and Neurobiology, 1239 Siping Road, Tongji University School of Medicine, Shanghai, 200092, China
| | - Chang-Ching Yang
- Department of Biomedical Sciences and Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Kwei-San, Tao-Yuan, Taiwan
| | - Bertrand Chin-Ming Tan
- Department of Biomedical Sciences and Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Kwei-San, Tao-Yuan, Taiwan
| | - Yi-Nan Lee
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | | | - Margaret S Ho
- Research Center for Translational Medicine, Shanghai East Hospital, Tongji University School of Medicine, No. 150 Jimo Road, Shanghai 200120, China.,Key Laboratory of Arrhythmias of the Ministry of Education of China, Shanghai East Hospital, Tongji University School of Medicine, No. 150 Jimo Road, Shanghai 200120, China.,Department of Anatomy and Neurobiology, 1239 Siping Road, Tongji University School of Medicine, Shanghai, 200092, China
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Masvidal L, Iniesta R, García M, Casalà C, Lavarino C, Mora J, de Torres C. Genetic variants in the promoter region of the calcium-sensing receptor gene are associated with its down-regulation in neuroblastic tumors. Mol Carcinog 2016; 56:1281-1289. [DOI: 10.1002/mc.22589] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 11/11/2016] [Indexed: 12/25/2022]
Affiliation(s)
- Laia Masvidal
- Developmental Tumor Biology Laboratory; Institut de Recerca; -Hospital Sant Joan de Déu; Esplugues de Llobregat; Barcelona Spain
| | - Raquel Iniesta
- Department of Medical and Molecular Genetics; King's College London; London United Kingdom
| | - Marta García
- Developmental Tumor Biology Laboratory; Institut de Recerca; -Hospital Sant Joan de Déu; Esplugues de Llobregat; Barcelona Spain
| | - Carla Casalà
- Developmental Tumor Biology Laboratory; Institut de Recerca; -Hospital Sant Joan de Déu; Esplugues de Llobregat; Barcelona Spain
| | - Cinzia Lavarino
- Developmental Tumor Biology Laboratory; Institut de Recerca; -Hospital Sant Joan de Déu; Esplugues de Llobregat; Barcelona Spain
- Department of Oncology; Institut de Recerca Pediàtrica-Hospital Sant Joan de Déu; Esplugues de Llobregat; Barcelona Spain
| | - Jaume Mora
- Developmental Tumor Biology Laboratory; Institut de Recerca; -Hospital Sant Joan de Déu; Esplugues de Llobregat; Barcelona Spain
- Department of Oncology; Institut de Recerca Pediàtrica-Hospital Sant Joan de Déu; Esplugues de Llobregat; Barcelona Spain
| | - Carmen de Torres
- Developmental Tumor Biology Laboratory; Institut de Recerca; -Hospital Sant Joan de Déu; Esplugues de Llobregat; Barcelona Spain
- Department of Oncology; Institut de Recerca Pediàtrica-Hospital Sant Joan de Déu; Esplugues de Llobregat; Barcelona Spain
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27
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Guan B, Welch JM, Sapp JC, Ling H, Li Y, Johnston JJ, Kebebew E, Biesecker LG, Simonds WF, Marx SJ, Agarwal SK. GCM2-Activating Mutations in Familial Isolated Hyperparathyroidism. Am J Hum Genet 2016; 99:1034-1044. [PMID: 27745835 DOI: 10.1016/j.ajhg.2016.08.018] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 08/29/2016] [Indexed: 02/05/2023] Open
Abstract
Primary hyperparathyroidism (PHPT) is a common endocrine disease characterized by parathyroid hormone excess and hypercalcemia and caused by hypersecreting parathyroid glands. Familial PHPT occurs in an isolated nonsyndromal form, termed familial isolated hyperparathyroidism (FIHP), or as part of a syndrome, such as multiple endocrine neoplasia type 1 or hyperparathyroidism-jaw tumor syndrome. The specific genetic or other cause(s) of FIHP are unknown. We performed exome sequencing on germline DNA of eight index-case individuals from eight unrelated kindreds with FIHP. Selected rare variants were assessed for co-segregation in affected family members and screened for in an additional 32 kindreds with FIHP. In eight kindreds with FIHP, we identified three rare missense variants in GCM2, a gene encoding a transcription factor required for parathyroid development. Functional characterization of the GCM2 variants and deletion analyses revealed a small C-terminal conserved inhibitory domain (CCID) in GCM2. Two of the three rare variants were recurrent, located in the GCM2 CCID, and found in seven of the 40 (18%) kindreds with FIHP. These two rare variants acted as gain-of-function mutations that increased the transcriptional activity of GCM2, suggesting that GCM2 is a parathyroid proto-oncogene. Our results demonstrate that germline-activating mutations affecting the CCID of GCM2 can cause FIHP.
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28
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Hendy GN, Canaff L. Calcium-Sensing Receptor Gene: Regulation of Expression. Front Physiol 2016; 7:394. [PMID: 27679579 PMCID: PMC5020072 DOI: 10.3389/fphys.2016.00394] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 08/23/2016] [Indexed: 12/13/2022] Open
Abstract
The human calcium-sensing receptor gene (CASR) has 8 exons, and localizes to chromosome 3q. Exons 1A and 1B encode alternative 5′-untranslated regions (UTRs) that splice to exon 2 encoding the AUG initiation codon. Exons 2–7 encode the CaSR protein of 1078 amino acids. Promoter P1 has TATA and CCAAT boxes upstream of exon 1A, and promoter P2 has Sp1/3 motifs at the start site of exon 1B. Exon 1A transcripts from the P1 promoter are reduced in parathyroid tumors and colon carcinomas. Studies of colon carcinomas and neuroblastomas have emphasized the importance of epigenetic changes—promoter methylation of the GC-rich P2 promoter, histone acetylation—as well as involvement of microRNAs in bringing about CASR gene silencing and reduced CaSR expression. Functional cis-elements in the CASR promoters responsive to 1,25-dihydroxyvitamin D [1,25(OH)2D], proinflammatory cytokines, and the transcription factor glial cells missing-2 (GCM2) have been characterized. Reduced levels of CaSR and reduced responsiveness to active vitamin D in parathyroid neoplasia and colon carcinoma may blunt the “tumor suppressor” activity of the CaSR. The hypocalcemia of critically ill patients with burn injury or sepsis is associated with CASR gene upregulation by TNF-alpha and IL-1beta via kappaB elements, and by IL-6 via Stat1/3 and Sp1/3 elements in the CASR gene promoters, respectively. The CASR is transactivated by GCM2—the expression of which is essential for parathyroid gland development. Hyperactive forms of GCM2 may contribute to later parathyroid hyperactivity or tumorigenesis. The expression of the CaSR—the calciostat—is regulated physiologically and pathophysiologically at the gene level.
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Affiliation(s)
- Geoffrey N Hendy
- Experimental Therapeutics and Metabolism, McGill University Health Centre-Research Institute, Departments of Medicine, Physiology, and Human Genetics, McGill University Montréal, QC, Canada
| | - Lucie Canaff
- Experimental Therapeutics and Metabolism, McGill University Health Centre-Research Institute, Departments of Medicine, Physiology, and Human Genetics, McGill University Montréal, QC, Canada
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29
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Sethi G, Chopra G, Samudrala R. Multiscale modelling of relationships between protein classes and drug behavior across all diseases using the CANDO platform. Mini Rev Med Chem 2016; 15:705-17. [PMID: 25694071 DOI: 10.2174/1389557515666150219145148] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Revised: 10/30/2014] [Accepted: 11/25/2014] [Indexed: 01/27/2023]
Abstract
We have examined the effect of eight different protein classes (channels, GPCRs, kinases, ligases, nuclear receptors, proteases, phosphatases, transporters) on the benchmarking performance of the CANDO drug discovery and repurposing platform (http://protinfo.org/cando). The first version of the CANDO platform utilizes a matrix of predicted interactions between 48278 proteins and 3733 human ingestible compounds (including FDA approved drugs and supplements) that map to 2030 indications/diseases using a hierarchical chem and bio-informatic fragment based docking with dynamics protocol (> one billion predicted interactions considered). The platform uses similarity of compound-proteome interaction signatures as indicative of similar functional behavior and benchmarking accuracy is calculated across 1439 indications/diseases with more than one approved drug. The CANDO platform yields a significant correlation (0.99, p-value < 0.0001) between the number of proteins considered and benchmarking accuracy obtained indicating the importance of multitargeting for drug discovery. Average benchmarking accuracies range from 6.2 % to 7.6 % for the eight classes when the top 10 ranked compounds are considered, in contrast to a range of 5.5 % to 11.7 % obtained for the comparison/control sets consisting of 10, 100, 1000, and 10000 single best performing proteins. These results are generally two orders of magnitude better than the average accuracy of 0.2% obtained when randomly generated (fully scrambled) matrices are used. Different indications perform well when different classes are used but the best accuracies (up to 11.7% for the top 10 ranked compounds) are achieved when a combination of classes are used containing the broadest distribution of protein folds. Our results illustrate the utility of the CANDO approach and the consideration of different protein classes for devising indication specific protocols for drug repurposing as well as drug discovery.
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Affiliation(s)
| | | | - Ram Samudrala
- Department of Biomedical Informatics, School of Medicine and Biomedical Sciences, State University of New York (SUNY), 923 Main Street, Buffalo, NY 14203, USA.
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30
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Hendy GN, Canaff L. Calcium-sensing receptor, proinflammatory cytokines and calcium homeostasis. Semin Cell Dev Biol 2015; 49:37-43. [PMID: 26612442 DOI: 10.1016/j.semcdb.2015.11.006] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 11/12/2015] [Indexed: 12/22/2022]
Abstract
The calcium-sensing receptor (CaSR) expressed in the parathyroid gland and the kidney tubule acts as the calciostat and orchestrates blood calcium homeostasis by modulating production and release of parathyroid hormone (PTH) and active vitamin D that influence Ca(2+) fluxes across the bone, kidney and intestine. Here we consider the role of the CaSR as a responder to proinflammatory cytokines released as part of the innate immune response to tissue injury and inflammation with resetting of the calciostat on the one hand and as a promoter and mediator of the initial inflammatory response on the other. The importance of the CaSR in systemic calcium homeostasis is exemplified by the fact that inactivating and activating mutations in the gene result in hypercalcemia and hypocalcemia, respectively. Proinflammatory cytokines interleukin-1β and interleukin-6 upregulate CaSR expression in parathyroid and kidney and do this through defined response elements in the CASR gene promoters. This results in decreased serum PTH and 1,25-dihydroxyvitamin D and calcium levels. This is likely to underlie the hypocalcemia that commonly occurs in critically ill patients, those with burn injury and sepsis, for example. The level of calcium in extracellular fluid bathing necrotic cells is often elevated and acts as a chemokine to attract monocytes/macrophages that express the CaSR to sites of tissue injury. Elevated levels of calcium acting via the CaSR can function as a danger signal that stimulates assembly of myeloid cell cytosolic multiprotein inflammasomes resulting in maturation of the proinflammatory cytokine IL-1β by caspase-1. Thus the CaSR is both promoter of and responder to the inflammation.
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Affiliation(s)
- Geoffrey N Hendy
- Experimental Therapeutics and Metabolism, McGill University Health Centre-Research Institute, and Departments of Medicine, Physiology and Human Genetics, McGill University, Montreal, Quebec, H4A 3J1, Canada.
| | - Lucie Canaff
- Experimental Therapeutics and Metabolism, McGill University Health Centre-Research Institute, and Departments of Medicine, Physiology and Human Genetics, McGill University, Montreal, Quebec, H4A 3J1, Canada
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31
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Han SI, Tsunekage Y, Kataoka K. Gata3 cooperates with Gcm2 and MafB to activate parathyroid hormone gene expression by interacting with SP1. Mol Cell Endocrinol 2015; 411:113-20. [PMID: 25917456 DOI: 10.1016/j.mce.2015.04.018] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Revised: 04/17/2015] [Accepted: 04/19/2015] [Indexed: 11/21/2022]
Abstract
Haploinsufficiency of the Gata3 gene, which encodes a zinc-finger transcription factor, is associated with the disorder hypoparathyroidism, deafness, and renal dysplasia (HDR) syndrome in humans. However, the roles of Gata3 in transcriptional regulation in the parathyroid glands are not well-understood. In this study, we show that Gata3 activates transcription of parathyroid hormone (PTH), which is secreted from parathyroid glands and is critical for regulating serum calcium and phosphate homeostasis. Gata3 interacted with Gcm2 and MafB, two known transcriptional regulators of parathyroid development, and synergistically stimulated the PTH promoter. An SP1-binding element (GC box) located within the PTH-promoter proximal region was critical for activating transcription by Gata3. In addition, the ubiquitous transcription factor SP1 also interacted with Gata3 as well as MafB and Gcm2, and HDR syndrome-associated Gata3 mutants were defective in activating the PTH promoter. These results suggest that Gata3 is a critical regulator of PTH gene expression.
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Affiliation(s)
- Song-Iee Han
- Laboratory of Molecular Medical Bioscience, Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Yukino Tsunekage
- Laboratory of Molecular Medical Bioscience, Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Kohsuke Kataoka
- Laboratory of Molecular Medical Bioscience, Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan.
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32
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Kwong RWM, Perry SF. An Essential Role for Parathyroid Hormone in Gill Formation and Differentiation of Ion-Transporting Cells in Developing Zebrafish. Endocrinology 2015; 156:2384-94. [PMID: 25872007 DOI: 10.1210/en.2014-1968] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In vertebrates, parathyroid hormone (PTH) is important for skeletogenesis and Ca(2+) homeostasis. However, little is known about the molecular mechanisms by which PTH regulates skeleton formation and Ca(2+) balance during early development. Using larval zebrafish as an in vivo model system, we determined that PTH1 regulates the differentiation of epithelial cells and the development of craniofacial cartilage. We demonstrated that translational gene knockdown of PTH1 decreased Ca(2+) uptake at 4 days after fertilization. We also observed that PTH1-deficient fish exhibited reduced numbers of epithelial Ca(2+) channel (ecac)-expressing cells, Na(+)/K(+)-ATPase-rich cells, and H(+)-ATPase-rich cells. Additionally, the density of epidermal stem cells was decreased substantially in the fish experiencing PTH1 knockdown. Knockdown of PTH1 caused a shortening of the jaw and impeded the development of branchial arches. Results from in situ hybridization suggested that the expression of collagen 2a1a (marker for proliferating chondrocytes) was substantially reduced in the cartilage that forms the jaw and branchial aches. Disorganization of chondrocytes in craniofacial cartilage also was observed in PTH1-deficient fish. The results of real-time PCR demonstrated that PTH1 morphants failed to express the transcription factor glial cell missing 2 (gcm2). Coinjection of PTH1 morpholino with gcm2 capped RNA rescued the phenotypes observed in the PTH1 morphants, suggesting that the defects in PTH1-deficient fish were caused, at least in part, by the suppression of gcm2. Taken together, the results of the present study reveal critical roles for PTH1 in promoting the differentiation of epidermal stem cells into mature ionocytes and cartilage formation during development.
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Affiliation(s)
- Raymond W M Kwong
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada K1N 6N5
| | - Steve F Perry
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada K1N 6N5
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33
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Thim SB, Birkebaek NH, Nissen PH, Høst C. Activating calcium-sensing receptor gene variants in children: a case study of infant hypocalcaemia and literature review. Acta Paediatr 2014; 103:1117-25. [PMID: 25039540 DOI: 10.1111/apa.12743] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Revised: 05/02/2014] [Accepted: 07/08/2014] [Indexed: 12/17/2022]
Abstract
UNLABELLED Autosomal dominant hypocalcaemia (ADH) is caused by activating variants in the calcium-sensing receptor (CASR) gene, but detailed information on the paediatric phenotype is limited. The current paper presents a case of severe ADH and systematically reviews the literature on ADH in children. CONCLUSION We found that the severity of clinical neurological symptoms was inversely related to serum calcium levels and a high prevalence of renal calcifications and/or basal ganglia calcifications in children with ADH.
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Affiliation(s)
- Signe B Thim
- Department of Paediatrics; Aarhus University Hospital; Aarhus Denmark
| | - Niels H Birkebaek
- Department of Paediatrics; Aarhus University Hospital; Aarhus Denmark
| | - Peter H Nissen
- Department of Clinical Biochemistry; Aarhus University Hospital; Aarhus Denmark
| | - Christian Høst
- Department of Paediatrics; Aarhus University Hospital; Aarhus Denmark
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Kumai Y, Kwong RWM, Perry SF. A role for transcription factor glial cell missing 2 in Ca2+ homeostasis in zebrafish, Danio rerio. Pflugers Arch 2014; 467:753-65. [PMID: 24893788 DOI: 10.1007/s00424-014-1544-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2014] [Revised: 05/10/2014] [Accepted: 05/26/2014] [Indexed: 01/06/2023]
Abstract
The present study investigated the role of the transcription factor, glial cell missing 2 (gcm2), in Ca(2+) regulation in zebrafish larvae. Translational gene knockdown of gcm2 decreased Ca(2+) uptake and the density of ionocytes expressing the epithelial Ca(2+) channel (ecac), and disrupted the overall Ca(2+) balance. Ca(2+) uptake and the expression of gcm2 messenger RNA (mRNA) were significantly elevated in larvae acclimated to low Ca(2+) water (25 μM); the stimulation of Ca(2+) uptake was not observed in fish experiencing gcm2 knockdown. Acclimation to acidic water (pH 4) significantly reduced whole-body Ca(2+) content owing to reduced Ca(2+) uptake and increased Ca(2+) efflux. However, ecac mRNA levels and the density of ecac-expressing ionocytes were increased in fish acclimated to acidic water, and maximal Ca(2+) uptake capacity (J MAX) was significantly increased when measured in control water (pH ~7.4). Acclimation of larvae to acidic water significantly increased gcm2 mRNA expression, and in gcm2 morphants, no such stimulation in Ca(2+) uptake was observed after their return to control water. Overexpression of gcm2 mRNA resulted in a significant increase in the numbers of ecac-expressing ionocytes and Ca(2+) uptake. These observations reveal a critical role for gcm2 in Ca(2+) homeostasis in zebrafish larvae.
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Affiliation(s)
- Yusuke Kumai
- Department of Biology, University of Ottawa, 30 Marie Curie, Ottawa, ON, K1N 6 N5, Canada
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35
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Generation of mice encoding a conditional null allele of Gcm2. Transgenic Res 2014; 23:631-41. [PMID: 24736975 DOI: 10.1007/s11248-014-9799-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Accepted: 04/04/2014] [Indexed: 10/25/2022]
Abstract
Glial cells missing homolog 2 (GCM2) is a transcription factor that is expressed predominately in the pharyngeal pouches and, at later stages, in the developing and mature parathyroid glands. In humans, loss of GCM2 function, either through recessive apomorphic mutations or dominant inhibitor mutations in the human GCM2 gene, leads to isolated hypoparathyroidism. In mice, homozygous disruption of Gcm2 by conventional gene targeting results in parathyroid aplasia and hypoparathyroidism. In this study, we report the generation and functional characterization of mice encoding a conditional null allele of Gcm2. We demonstrate the functional integrity of the conditional Gcm2 allele and report successful in vivo deletion of exon 2 using Cre recombinase. The mice with conditional deletion of Gcm2 displayed phenotypes similar to those previously described for a conventional Gcm2 knockout, including perinatal lethality, hypocalemia, low or undetectable serum levels of parathyroid hormone, and absent parathyroid glands. The production of a conditional mutant allele for Gcm2 represents a valuable resource for the study of the temporal- and spatial-specific roles for Gcm2, and for understanding the postnatal activities of GCM2 protein.
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36
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Hendy GN, Canaff L, Cole DEC. The CASR gene: alternative splicing and transcriptional control, and calcium-sensing receptor (CaSR) protein: structure and ligand binding sites. Best Pract Res Clin Endocrinol Metab 2013; 27:285-301. [PMID: 23856260 DOI: 10.1016/j.beem.2013.02.009] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The calcium-sensing receptor (CaSR) is a G protein-coupled receptor encoded by a single copy gene. The human CASR gene spans ~103-kb and has eight exons. Promoters P1 and P2 drive transcription of exons 1A and 1B, respectively, encoding alternative 5'-UTRs that splice to exon 2 encoding the common part of the 5'-UTR. Exons 2-7 encode the CaSR protein of 1078 amino acids. Functional elements responsive to 1,25-dihydroxyvitamin D, proinflammatory cytokines, and glial cells missing-2 are present in the CASR promoters. Evolutionarily, the exon structure, first seen in aquatic vertebrates, is well-conserved with a single linkage disequilibrium haplotype block for protein coding exons 2-7. Structural features of the human CaSR protein are: an N-terminal signal peptide (19 amino acids (aa)); an extracellular domain (~600 aa) having a bi-lobed Venus Flytrap (VFT) domain with several Ca(2+)-binding sites; and a nine-cysteines domain that transduces the activation signal to the 7-transmembrane domain (250 aa) and the C-terminal tail (216 aa).
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Affiliation(s)
- Geoffrey N Hendy
- Calcium Research Laboratory, and Hormones and Cancer Research Unit, Royal Victoria Hospital and McGill University Health Centre, Montreal, QC H3A 1A1, Canada.
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37
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Mao H, Lv Z, Ho MS. Gcm proteins function in the developing nervous system. Dev Biol 2012; 370:63-70. [PMID: 22842100 DOI: 10.1016/j.ydbio.2012.07.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2012] [Revised: 07/02/2012] [Accepted: 07/10/2012] [Indexed: 11/17/2022]
Abstract
A fundamental issue during nervous system development is how individual cells are formed from the undefined precursors. Differentiated neurons and glia, two major cell types mediating neuronal function, are acquired from immature precursors via a series of explicit controls exerted by transcription factors such as proteins in the family of Glial cells missing (Gcm). In mammals, Gcm proteins are involved in placenta and parathyroid gland development, whereas in the invertebrate organism Drosophila, Gcm proteins act as fate determinants for glial cell fate, regulate neural stem cell (NSC) induction and conversion, and promote glial proliferation. In particular, Gcm protein levels are carefully tuned for Drosophila gliogenesis and their stability is under precise control via the ubiquitin-proteasome system (UPS). Here we summarize recent advances on Gcm proteins function. In addition to describe various features of Gcm protein family, the significance of their functions in the developing nervous system is also discussed.
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Affiliation(s)
- Haian Mao
- Department of Nuclear Medicine, Shanghai Tenth Hospital, Tongji University, Shanghai 200072, China
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Yi HS, Eom YS, Park IB, Lee S, Hong S, Jüppner H, Mannstadt M, Lee S. Identification and characterization of C106R, a novel mutation in the DNA-binding domain of GCMB, in a family with autosomal-dominant hypoparathyroidism. Clin Endocrinol (Oxf) 2012; 76:625-33. [PMID: 22066718 PMCID: PMC3701386 DOI: 10.1111/j.1365-2265.2011.04256.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
OVERVIEW Glial cells missing B (GCMB) is a transcription factor that is expressed in the parathyroid hormone (PTH)-secreting cells of the parathyroid glands. Several mutations in GCMB have been reported to cause hypoparathyroidism (HP). We identified a family with two individuals in two generations (mother and son), who are affected by autosomal-dominant hypoparathyroidism (AD-HP). A novel heterozygous mutation in exon 2 of GCMB was identified in both affected individuals that changes cysteine at position 106 of the putative DNA-binding domain of GCMB to arginine (C106R). METHODS We performed mutational analysis of the genes encoding GCMB, pre-pro PTH, GATA3 and CaSR using polymerase chain reaction (PCR)-amplified genomic DNA. The identified GCMB mutant was characterized by functional studies including nuclear localization, electrophoretic mobility shift assays (EMSA) and luciferase reporter assays, and homology modelling was performed to generate a three-dimensional structural model for the DNA-binding domain of GCMB to predict the structural consequences of the identified mutation. RESULTS The C106R mutant of GCMB failed to interact with the DNA consensus recognition motif, as determined by EMSA. Furthermore, in comparison with wild-type GCMB, the C106R mutant demonstrated reduced transactivation in luciferase reporter assays; however, the mutant GCMB failed to reduce the activity of the wild-type protein. Consistent with the EMSA findings, homology modelling analysis suggested that replacement of cysteine 106 with arginine would interfere with DNA binding. CONCLUSIONS We have identified a novel GCMB mutation that may explain AD-HP in our family. However, the exact mechanism by which this heterozygous mutation leads to the disease in the described family remains to be elucidated.
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Affiliation(s)
- Hyon-Seung Yi
- Department of Internal Medicine and Laboratory of Molecular Endocrinology, Gachon University School of Medicine, Incheon
| | - Young Sil Eom
- Department of Internal Medicine and Laboratory of Molecular Endocrinology, Gachon University School of Medicine, Incheon
| | - Ie Byung Park
- Department of Internal Medicine and Laboratory of Molecular Endocrinology, Gachon University School of Medicine, Incheon
| | - Sangho Lee
- Department of Biological Sciences, Sungkyunkwan University, Suwon
| | - Suntaek Hong
- Laboratory of Cancer Cell Biology, Lee Gil Ya Cancer and Diabetes Institute, Gachon University of Medicine and Science, Incheon, Korea
| | - Harald Jüppner
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- Pediatric Nephrology Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Michael Mannstadt
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Sihoon Lee
- Department of Internal Medicine and Laboratory of Molecular Endocrinology, Gachon University School of Medicine, Incheon
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Huang Y, Cavanaugh A, Breitwieser GE. Regulation of stability and trafficking of calcium-sensing receptors by pharmacologic chaperones. ADVANCES IN PHARMACOLOGY 2012; 62:143-73. [PMID: 21907909 DOI: 10.1016/b978-0-12-385952-5.00007-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Gain- or loss-of-function mutations and polymorphisms of the calcium-sensing receptor (CaSR) cause Ca(2+) handling diseases. Altered expression and/or signaling of wild-type CaSR can also contribute to pathology. Recent studies have demonstrated that a significant proportion of mutations cause altered targeting and/or trafficking of CaSR to the plasma membrane. Pharmacological approaches to rescue of CaSR function include treatment with allosteric modulators, which potentiate the effects of the orthosteric agonist Ca(2+). Dissection of the mechanism(s) contributing to allosteric agonist-mediated rescue of loss-of-function CaSR mutants has demonstrated pharmacologic chaperone actions coincident with CaSR biosynthesis. The distinctive responses to the allosteric agonist (NPS R-568), which promotes CaSR stability, and the allosteric antagonist (NPS 2143), which promotes CaSR degradation, have led to a model for a conformational checkpoint during CaSR biosynthesis. The conformational checkpoint would "tune" CaSR biosynthesis to cellular signaling state. Navigation of a distinct checkpoint for endoplasmic release can also be augmented by pharmacologic chaperones. The diverse, post-endoplasmic reticulum quality control site(s) for pharmacologic chaperone modulation of CaSR stability and trafficking redefines the role(s) of allosteric modulators in regulation of overall GPCR function.
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Affiliation(s)
- Ying Huang
- Cancer Drug Research Laboratory, McGill University, Royal Victoria Hospital, Montreal, Quebec, Canada
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Grigorieva IV, Thakker RV. Transcription factors in parathyroid development: lessons from hypoparathyroid disorders. Ann N Y Acad Sci 2012; 1237:24-38. [PMID: 22082362 DOI: 10.1111/j.1749-6632.2011.06221.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Parathyroid developmental anomalies, which result in hypoparathyroidism, are common and may occur in one in 4,000 live births. Parathyroids, in man, develop from the endodermal cells of the third and fourth pharyngeal pouches, whereas, in the mouse they develop solely from the endoderm of the third pharyngeal pouches. In addition, neural crest cells that arise from the embryonic mid- and hindbrain also contribute to parathyroid gland development. The molecular signaling pathways that are involved in determining the differentiation of the pharyngeal pouch endoderm into parathyroid cells are being elucidated by studies of patients with hypoparathyroidism and appropriate mouse models. These studies have revealed important roles for a number of transcription factors, which include Tbx1, Gata3, Gcm2, Sox3, Aire1 and members of the homeobox (Hox) and paired box (Pax) families.
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Affiliation(s)
- Irina V Grigorieva
- Academic Endocrine Unit, Nuffield Department of Clinical Medicine, Oxford Centre for Diabetes, Endocrinology, and Metabolism, Churchill Hospital, University of Oxford, Headington, Oxford, United Kingdom
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Doyle D, Kirwin SM, Sol-Church K, Levine MA. A novel mutation in the GCM2 gene causing severe congenital isolated hypoparathyroidism. J Pediatr Endocrinol Metab 2012; 25:741-6. [PMID: 23155703 PMCID: PMC3694175 DOI: 10.1515/jpem-2012-0080] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
OBJECTIVE To investigate the GCM2 gene in three siblings with congenital hypoparathyroidism and perform functional analysis. MATERIALS AND METHODS We sequenced the GCM2 gene by PCR and analyzed the functional consequence of the mutation by transient transfection studies. Haplotype analysis was performed. RESULTS We identified a nucleotide change, c.408C>A, in exon 3 that is predicted to truncate the Gcm2 protein (p.Tyr136Ter). All three affected siblings were homozygous and both parents were heterozygous for the mutation. Transfection studies revealed the mutant mRNA but not expression of the Gcm2 protein. Haplotype analysis revealed that the two mutant GCM2 alleles shared genotypes on chromosome 6p24.2. CONCLUSIONS We describe the first GCM2 mutation in exon 3 in patients with severe congenital hypoparathyroidism. Informative genetic markers could not exclude identity by descent for the mutant alleles. Gcm2 protein was not detected after transfection, suggesting that complete lack of Gcm2 action accounts for severe hypoparathyroidism.
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Affiliation(s)
- Daniel Doyle
- Division of Endocrinology, Nemours/Alfred I. duPont Hospital for Children, P.O. Box 269, Wilmington, DE 19803, USA.
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Kamitani-Kawamoto A, Hamada M, Moriguchi T, Miyai M, Saji F, Hatamura I, Nishikawa K, Takayanagi H, Hitoshi S, Ikenaka K, Hosoya T, Hotta Y, Takahashi S, Kataoka K. MafB interacts with Gcm2 and regulates parathyroid hormone expression and parathyroid development. J Bone Miner Res 2011; 26:2463-72. [PMID: 21713993 DOI: 10.1002/jbmr.458] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Serum calcium and phosphate homeostasis is critically regulated by parathyroid hormone (PTH) secreted by the parathyroid glands. Parathyroid glands develop from the bilateral parathyroid-thymus common primordia. In mice, the expression of transcription factor Glial cell missing 2 (Gcm2) begins in the dorsal/anterior part of the primordium on embryonic day 9.5 (E9.5), specifying the parathyroid domain. The parathyroid primordium then separates from the thymus primordium and migrates to its adult location beside the thyroid gland by E15.5. Genetic ablation of gcm2 results in parathyroid agenesis in mice, indicating that Gcm2 is essential for early parathyroid organogenesis. However, the regulation of parathyroid development at later stages is not well understood. Here we show that transcriptional activator v-maf musculoaponeurotic fibrosarcoma oncogene homologue B (MafB) is developmentally expressed in parathyroid cells after E11.5. MafB expression was lost in the parathyroid primordium of gcm2 null mice. The parathyroid glands of mafB(+/-) mice were mislocalized between the thymus and thyroid. In mafB(-/-) mice, the parathyroid did not separate from the thymus. Furthermore, in mafB(-/-) mice, PTH expression and secretion were impaired; expression levels of renal cyp27b1, one of the target genes of PTH, was decreased; and bone mineralization was reduced. We also demonstrate that although Gcm2 alone does not stimulate the PTH gene promoter, it associates with MafB to synergistically activate PTH expression. Taken together, our results suggest that MafB regulates later steps of parathyroid development, that is, separation from the thymus and migration toward the thyroid. MafB also regulates the expression of PTH in cooperation with Gcm2.
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Affiliation(s)
- Akiyo Kamitani-Kawamoto
- Laboratory of Molecular and Developmental Biology, Graduate School of Biological Science, Nara Institute of Science and Technology, Ikoma, Japan
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Mannstadt M, Holick E, Zhao W, Jüppner H. Mutational analysis of GCMB, a parathyroid-specific transcription factor, in parathyroid adenoma of primary hyperparathyroidism. J Endocrinol 2011; 210:165-71. [PMID: 21642377 PMCID: PMC3689587 DOI: 10.1530/joe-10-0247] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Sporadic primary hyperparathyroidism (PHPT), one of the most common endocrine disorders, is characterized by hypercalcemia and elevated PTH levels. The majority of cases are caused by a benign parathyroid adenoma, but somatic or de novo germ-line mutations that lead to adenoma formation have only been identified in few glands. GCMB is a parathyroid-specific transcription factor, which causes hypoparathyroidism when inactivated on both parental alleles or when a dominant-negative, heterozygous mutation is present. It is overexpressed in some parathyroid adenomas, and we therefore tested the hypothesis that GCMB mutations can be a cause of parathyroid adenomas. Nucleotide sequence analysis was performed on all coding exons and exon-intron borders of GCMB in 30 sporadic parathyroid adenomas and we identified several known polymorphisms that were either heterozygous or homozygous. In addition, one of the 30 investigated glands revealed a novel heterozygous missense mutation, c.1144G>A, which introduced methionine at position 382 for valine (V382M), a conserved amino acid residue. Western blot analysis using mutant GCMB (GCMB-V382M) from lysates of transiently transfected DF-1 fibroblasts, luciferase assays using extracts from these cells, and electrophoretic mobility assays failed to reveal differences between wild-type and mutant GCMB in expression level, transactivational capacity, and DNA-binding ability. Furthermore, pulse-chase experiments demonstrated no difference in half-life of wild-type and mutant protein. We conclude that mutations in the transcription factor GCMB do not seem to play a major role in the pathogenesis of PHPT.
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Affiliation(s)
- Michael Mannstadt
- Endocrine Unit Pediatric Nephrology Unit, Massachusetts General Hospital and Harvard Medical School, Thier 1051, 55 Fruit Street, Boston, Massachusetts 02114, USA.
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Shh signalling restricts the expression of Gcm2 and controls the position of the developing parathyroids. Dev Biol 2011; 353:194-205. [DOI: 10.1016/j.ydbio.2011.02.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Revised: 02/12/2011] [Accepted: 02/14/2011] [Indexed: 11/24/2022]
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Abstract
Compelling evidence of a cell surface receptor sensitive to extracellular calcium was observed as early as the 1980s and was finally realized in 1993 when the calcium-sensing receptor (CaR) was cloned from bovine parathyroid tissue. Initial studies relating to the CaR focused on its key role in extracellular calcium homeostasis, but as the amount of information about the receptor grew it became evident that it was involved in many biological processes unrelated to calcium homeostasis. The CaR responds to a diverse array of stimuli extending well beyond that merely of calcium, and these stimuli can lead to the initiation of a wide variety of intracellular signaling pathways that in turn are able to regulate a diverse range of biological processes. It has been through the examination of the molecular characteristics of the CaR that we now have an understanding of how this single receptor is able to convert extracellular messages into specific cellular responses. Recent CaR-related reviews have focused on specific aspects of the receptor, generally in the context of the CaR's role in physiology and pathophysiology. This review will provide a comprehensive exploration of the different aspects of the receptor, including its structure, stimuli, signalling, interacting protein partners, and tissue expression patterns, and will relate their impact on the functionality of the CaR from a molecular perspective.
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Affiliation(s)
- Aaron L Magno
- Department of Endocrinology and Diabetes, First Floor, C Block, Sir Charles Gairdner Hospital, Hospital Avenue, Nedlands 6009, Western Australia, Australia
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Mirczuk SM, Bowl MR, Nesbit MA, Cranston T, Fratter C, Allgrove J, Brain C, Thakker RV. A missense glial cells missing homolog B (GCMB) mutation, Asn502His, causes autosomal dominant hypoparathyroidism. J Clin Endocrinol Metab 2010; 95:3512-6. [PMID: 20463099 DOI: 10.1210/jc.2009-2532] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
CONTEXT Glial cells missing B (GCMB), the mammalian homolog of the Drosophila GCM gene, encodes a 506-amino-acid parathyroid-specific transcription factor. To date, only two different heterozygous GCMB mutations have been reported in three kindreds with autosomal dominant hypoparathyroidism. OBJECTIVE Our objective was to investigate a family with autosomal dominant hypoparathyroidism for PTH, CaSR, and GCMB mutations. METHODS Leukocyte DNA was used with exon-specific primers for PCR amplification and the DNA sequences of the PCR products determined. Functional analyses using fluorescence microscopy, EMSAs, and luciferase reporter assays were undertaken. Informed consent was obtained using protocols approved by a national ethical committee. RESULTS DNA sequence analysis revealed an A to C transversion at codon 502 of GCMB, which altered the wild-type asparagine (Asn) to histidine (His). Functional studies, using transient transfections of COS7 cells with GCMB wild-type and mutant (Asn502His) tagged constructs, demonstrated that the wild-type and mutant proteins localized to the nucleus and retained the ability to bind the GCM-consensus DNA recognition motif. However, a luciferase reporter assay demonstrated that the Asn502His mutation resulted in a reduction in gene transactivation. Moreover, cotransfection of the wild-type with mutant did not lead to an increase in luciferase activity, thereby demonstrating a dominant-negative effect of the Asn502His mutant that would be consistent with an autosomal dominant inheritance. CONCLUSION Our results, which have identified the first dominant missense GCMB mutation, help to increase our understanding of the mechanism underlying gene transactivation that is a prerequisite for the function of this parathyroid gland-specific transcription factor.
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Affiliation(s)
- Samantha M Mirczuk
- Academic Endocrine Unit, Nuffield Department of Clinical Medicine, University of Oxford, Oxford Centre for Diabetes, Endocrinology, and Metabolism (OCDEM), Churchill Hospital, Headington Oxford OX3 7LJ, UK
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47
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Affiliation(s)
- Dominique Prié
- Growth and Signaling Research Center and the Department of Physiology, INSERM Unité 845, Paris Descartes University, Paris, France
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48
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Grigorieva IV, Mirczuk S, Gaynor KU, Nesbit MA, Grigorieva EF, Wei Q, Ali A, Fairclough RJ, Stacey JM, Stechman MJ, Mihai R, Kurek D, Fraser WD, Hough T, Condie BG, Manley N, Grosveld F, Thakker RV. Gata3-deficient mice develop parathyroid abnormalities due to dysregulation of the parathyroid-specific transcription factor Gcm2. J Clin Invest 2010; 120:2144-55. [PMID: 20484821 DOI: 10.1172/jci42021] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2009] [Accepted: 03/31/2010] [Indexed: 12/23/2022] Open
Abstract
Heterozygous mutations of GATA3, which encodes a dual zinc-finger transcription factor, cause hypoparathyroidism with sensorineural deafness and renal dysplasia. Here, we have investigated the role of GATA3 in parathyroid function by challenging Gata3+/- mice with a diet low in calcium and vitamin D so as to expose any defects in parathyroid function. This led to a higher mortality among Gata3+/- mice compared with Gata3+/+ mice. Compared with their wild-type littermates, Gata3+/- mice had lower plasma concentrations of calcium and parathyroid hormone (PTH) and smaller parathyroid glands with a reduced Ki-67 proliferation rate. At E11.5, Gata3+/- embryos had smaller parathyroid-thymus primordia with fewer cells expressing the parathyroid-specific gene glial cells missing 2 (Gcm2), the homolog of human GCMB. In contrast, E11.5 Gata3-/- embryos had no Gcm2 expression and by E12.5 had gross defects in the third and fourth pharyngeal pouches, including absent parathyroid-thymus primordia. Electrophoretic mobility shift, luciferase reporter, and chromatin immunoprecipitation assays showed that GATA3 binds specifically to a functional double-GATA motif within the GCMB promoter. Thus, GATA3 is critical for the differentiation and survival of parathyroid progenitor cells and, with GCM2/B, forms part of a transcriptional cascade in parathyroid development and function.
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Affiliation(s)
- Irina V Grigorieva
- Academic Endocrine Unit, Nuffield Department of Clinical Medicine, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), Churchill Hospital, Headington, Oxford, United Kingdom
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Bowl MR, Mirczuk SM, Grigorieva IV, Piret SE, Cranston T, Southam L, Allgrove J, Bahl S, Brain C, Loughlin J, Mughal Z, Ryan F, Shaw N, Thakker YV, Tiosano D, Nesbit MA, Thakker RV. Identification and characterization of novel parathyroid-specific transcription factor Glial Cells Missing Homolog B (GCMB) mutations in eight families with autosomal recessive hypoparathyroidism. Hum Mol Genet 2010; 19:2028-38. [PMID: 20190276 DOI: 10.1093/hmg/ddq084] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
GCMB is a member of the small transcription factor family GCM (glial cells missing), which are important regulators of development, present in vertebrates and some invertebrates. In man, GCMB encodes a 506 amino acid parathyroid gland-specific protein, mutations of which have been reported to cause both autosomal dominant and autosomal recessive hypoparathyroidism. We ascertained 18 affected individuals from 12 families with autosomal recessive hypoparathyroidism and have investigated them for GCMB abnormalities. Four different homozygous germline mutations were identified in eight families that originate from the Indian Subcontinent. These consisted of a novel nonsense mutation R39X; a missense mutation, R47L in two families; a novel missense mutation, R110W; and a novel frameshifting deletion, I298fsX307 in four families. Haplotype analysis, using polymorphic microsatellites from chromosome 6p23-24, revealed that R47L and I298fsX307 mutations arose either as ancient founders, or recurrent de novo mutations. Functional studies including: subcellular localization studies, EMSAs and luciferase-reporter assays, were undertaken and these demonstrated that: the R39X mutant failed to localize to the nucleus; the R47L and R110W mutants both lost DNA-binding ability; and the I298fsX307 mutant had reduced transactivational ability. In order to gain further insights, we undertook 3D-modeling of the GCMB DNA-binding domain, which revealed that the R110 residue is likely important for the structural integrity of helix 2, which forms part of the GCMB/DNA binding interface. Thus, our results, which expand the spectrum of hypoparathyroidism-associated GCMB mutations, help elucidate the molecular mechanisms underlying DNA-binding and transactivation that are required for this parathyroid-specific transcription factor.
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Affiliation(s)
- Michael R Bowl
- Academic Endocrine Unit, Nuffield Department of Clinical Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Headington, Oxford OX3 7LJ, UK
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Abstract
Glial cells missing-2 (Gcm2) is the key regulating transcription factor for parathyroid gland development. The continued expression of high levels of Gcm2 in mature parathyroid glands suggests that it is required for maintenance of parathyroid cell differentiation. The role of Gcm2 in parathyroid cell physiology, however, has not been fully studied. In this study, we examined the effects of Gcm2 silencing on cultured human parathyroid cells. Collagenase-dispersed human parathyroid cells from patients with chronic kidney disease were placed in monolayer cultures and infected with lentivirus expressing shRNA for human Gcm2. Seventy-two hours after infection, mRNA was processed and analyzed for Gcm2, PTH, vitamin D receptor (VDR), calcium-sensing receptor (CaR), 25-hydroxyvitamin D(3) 1-alpha-hydroxylase (1-OHase), and proliferating cell nuclear antigen (PCNA) by real-time PCR (qPCR). Protein expression of affected genes was analyzed by immunoblot 72 h after infection. Gcm2 mRNA and protein were decreased by 74.2 +/- 12.2% (SD; n = 3 experiments; p < 0.01) and 67.5 +/- 15.7% (n = 2; p < 0.01), respectively. CaR mRNA and protein were reduced by 47.8 +/- 21.1% (n = 3; p < 0.01) and 48.1 +/- 4.3% (n = 3; p < 0.01), respectively. However, VDR, PTH, 1-OHase, and PCNA were not significantly affected by Gcm2 silencing. Further analysis of CaR mRNA indicated that transcripts containing exon 1B, derived by transcription from CaR promoter 2, were downregulated (58.8 +/- 19.27%; n = 3; p < 0.05) by Gcm2 silencing. Exon 1A-containing transcripts from promoter 1 were expressed at very low levels in the cultures. These results indicate that one function of Gcm2 is to maintain high levels of CaR expression in parathyroid cells.
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