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Höppner J, Jüppner H. Rare genetic disorders that impair parathyroid hormone synthesis, secretion, or bioactivity provide insights into the diagnostic utility of different parathyroid hormone assays. Curr Opin Nephrol Hypertens 2024; 33:375-382. [PMID: 38701324 DOI: 10.1097/mnh.0000000000000999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2024]
Abstract
PURPOSE OF REVIEW Parathyroid hormone (PTH) is the major peptide hormone regulator of blood calcium homeostasis. Abnormal PTH levels can be observed in patients with various congenital and acquired disorders, including chronic kidney disease (CKD). This review will focus on rare human diseases caused by PTH mutations that have provided insights into the regulation of PTH synthesis and secretion as well as the diagnostic utility of different PTH assays. RECENT FINDINGS Over the past years, numerous diseases affecting calcium and phosphate homeostasis have been defined at the molecular level that are responsible for reduced or increased serum PTH levels. The underlying genetic mutations impair parathyroid gland development, involve the PTH gene itself, or alter function of the calcium-sensing receptor (CaSR) or its downstream signaling partners that contribute to regulation of PTH synthesis or secretion. Mutations in the pre sequence of the mature PTH peptide can, for instance, impair hormone synthesis or intracellular processing, while amino acid substitutions affecting the secreted PTH(1-84) impair PTH receptor (PTH1R) activation, or cause defective cleavage of the pro-sequence and thus secretion of a pro- PTH with much reduced biological activity. Mutations affecting the secreted hormone can alter detection by different PTH assays, thus requiring detailed knowledge of the utilized diagnostic test. SUMMARY Rare diseases affecting PTH synthesis and secretion have offered helpful insights into parathyroid biology and the diagnostic utility of commonly used PTH assays, which may have implications for the interpretation of PTH measurements in more common disorders such as CKD.
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Affiliation(s)
| | - Harald Jüppner
- Endocrine Unit
- Pediatric Nephrology Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
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2
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Cetani F, Dinoi E, Pierotti L, Pardi E. Familial states of primary hyperparathyroidism: an update. J Endocrinol Invest 2024:10.1007/s40618-024-02366-7. [PMID: 38635114 DOI: 10.1007/s40618-024-02366-7] [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: 10/25/2023] [Accepted: 03/24/2024] [Indexed: 04/19/2024]
Abstract
BACKGROUND Familial primary hyperparathyroidism (PHPT) includes syndromic and non-syndromic disorders. The former are characterized by the occurrence of PHPT in association with extra-parathyroid manifestations and includes multiple endocrine neoplasia (MEN) types 1, 2, and 4 syndromes, and hyperparathyroidism-jaw tumor (HPT-JT). The latter consists of familial hypocalciuric hypercalcemia (FHH) types 1, 2 and 3, neonatal severe primary hyperparathyroidism (NSHPT), and familial isolated primary hyperparathyroidism (FIHP). The familial forms of PHPT show different levels of PHPT penetrance, developing earlier and with multiglandular involvement compared to sporadic counterpart. All these diseases exhibit Mendelian inheritance patterns, and for most of them, the genes responsible have been identified. DNA testing for predisposing mutations is helpful in index cases or in individuals with a high suspicion of the disease. Early recognition of hereditary disorders of PHPT is of great importance for the best clinical and surgical approach. Genetic testing is useful in routine clinical practice because it will also involve appropriate screening for extra-parathyroidal manifestations related to the syndrome as well as the identification of asymptomatic carriers of the mutation. PURPOSE The aim of the review is to discuss the current knowledge on the clinical and genetic profile of these disorders along with the importance of genetic testing in clinical practice.
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Affiliation(s)
- F Cetani
- Endocrine Unit 2, University Hospital of Pisa, Via Paradisa 2, 56124, Pisa, Italy.
| | - E Dinoi
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - L Pierotti
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - E Pardi
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
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3
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Koo KC, Halawani A, Wong VK, Lange D, Chew BH. Monogenic features of urolithiasis: A comprehensive review. Asian J Urol 2024; 11:169-179. [PMID: 38680588 PMCID: PMC11053333 DOI: 10.1016/j.ajur.2023.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 03/28/2023] [Indexed: 05/01/2024] Open
Abstract
Objective Urolithiasis formation has been attributed to environmental and dietary factors. However, evidence is accumulating that genetic background can contribute to urolithiasis formation. Advancements in the identification of monogenic causes using high-throughput sequencing technologies have shown that urolithiasis has a strong heritable component. Methods This review describes monogenic factors implicated in a genetic predisposition to urolithiasis. Peer-reviewed journals were evaluated by a PubMed search until July 2023 to summarize disorders associated with monogenic traits, and discuss clinical implications of identification of patients genetically susceptible to urolithiasis formation. Results Given that more than 80% of urolithiases cases are associated with calcium accumulation, studies have focused mainly on monogenetic contributors to hypercalciuric urolithiases, leading to the identification of receptors, channels, and transporters involved in the regulation of calcium renal tubular reabsorption. Nevertheless, available candidate genes and linkage methods have a low resolution for evaluation of the effects of genetic components versus those of environmental, dietary, and hormonal factors, and genotypes remain undetermined in the majority of urolithiasis formers. Conclusion The pathophysiology underlying urolithiasis formation is complex and multifactorial, but evidence strongly suggests the existence of numerous monogenic causes of urolithiasis in humans.
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Affiliation(s)
- Kyo Chul Koo
- Department of Urology, Yonsei University College of Medicine, Seoul, Republic of Korea
| | | | - Victor K.F. Wong
- Department of Urological Sciences, University of British Columbia, Stone Centre at Vancouver General Hospital, Vancouver, British Columbia, Canada
| | - Dirk Lange
- Department of Urological Sciences, University of British Columbia, Stone Centre at Vancouver General Hospital, Vancouver, British Columbia, Canada
| | - Ben H. Chew
- Department of Urological Sciences, University of British Columbia, Stone Centre at Vancouver General Hospital, Vancouver, British Columbia, Canada
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Saglia C, Arruga F, Scolari C, Kalantari S, Albanese S, Bracciamà V, Corso Faini A, Brach Del Prever G, Luca M, Romeo C, Mioli F, Migliorero M, Tessaris D, Carli D, Amoroso A, Vaisitti T, De Sanctis L, Deaglio S. Functional evaluation of a novel nonsense variant of the calcium-sensing receptor gene leading to hypocalcemia. Eur J Endocrinol 2024; 190:296-306. [PMID: 38561929 DOI: 10.1093/ejendo/lvae035] [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: 12/04/2023] [Revised: 03/06/2024] [Accepted: 03/08/2024] [Indexed: 04/04/2024]
Abstract
OBJECTIVE The calcium-sensing receptor (CASR) gene encodes a G protein-coupled receptor crucial for calcium homeostasis. Gain-of-function CASR variants result in hypocalcemia, while loss-of-function variants lead to hypercalcemia. This study aims to assess the functional consequences of the novel nonsense CASR variant [c.2897_2898insCTGA, p.(Gln967*) (Q967*)] identified in adolescent patient with chronic hypocalcemia, a phenotype expected for a gain-of-function variants. DESIGN AND METHODS To functionally characterize the Q967* mutant receptor, both wild-type (WT) and mutant CASR were transiently transfected into HEK293T cells and calcium-sensing receptor (CaSR) protein expression and functions were comparatively evaluated using multiple read-outs. RESULTS Western blot analysis revealed that the CaSR mutant protein displayed a lower molecular weight compared with the WT, consistent with the loss of the last 122 amino acids in the intracellular domain. Mitogen-activated protein kinase activation and serum responsive element luciferase assays demonstrated that the mutant receptor had higher baseline activity than the WT. Extracellular-signal-regulated kinase/c-Jun N-terminal kinase phosphorylation, however, remained consistently high in the mutant, without significant modulations following exposure to increasing extracellular calcium (Ca2+o) levels, suggesting that the mutant receptor is more sensitive to Ca2+o compared with the WT. CONCLUSIONS This study provides functional validation of the pathogenicity of a novel nonsense CASR variant, resulting in an abnormally hyperfunctioning protein consistent with the patient's phenotype. Functional analyses indicate that mutant receptor is constitutively active and poorly sensitive to increasing concentrations of extracellular calcium, suggesting that the cytoplasmic tail may contain elements regulating signal transduction.
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Affiliation(s)
- Claudia Saglia
- Department of Medical Sciences, University of Turin, Turin 10126, Italy
- Immunogenetics and Transplant Biology Unit, Città della Salute e della Scienza Hospital, Turin 10126, Italy
| | - Francesca Arruga
- Department of Medical Sciences, University of Turin, Turin 10126, Italy
- Immunogenetics and Transplant Biology Unit, Città della Salute e della Scienza Hospital, Turin 10126, Italy
| | - Caterina Scolari
- Department of Medical Sciences, University of Turin, Turin 10126, Italy
- Immunogenetics and Transplant Biology Unit, Città della Salute e della Scienza Hospital, Turin 10126, Italy
| | - Silvia Kalantari
- Department of Medical Sciences, University of Turin, Turin 10126, Italy
- Immunogenetics and Transplant Biology Unit, Città della Salute e della Scienza Hospital, Turin 10126, Italy
| | - Serena Albanese
- Department of Public Health and Pediatric Sciences, University of Torino, Torino 10126, Italy
- Pediatric Endocrinology, Regina Margherita Childrens' Hospital, Torino 10126, Italy
| | - Valeria Bracciamà
- Department of Medical Sciences, University of Turin, Turin 10126, Italy
- Immunogenetics and Transplant Biology Unit, Città della Salute e della Scienza Hospital, Turin 10126, Italy
| | - Angelo Corso Faini
- Department of Medical Sciences, University of Turin, Turin 10126, Italy
- Immunogenetics and Transplant Biology Unit, Città della Salute e della Scienza Hospital, Turin 10126, Italy
| | - Giulia Brach Del Prever
- Department of Medical Sciences, University of Turin, Turin 10126, Italy
- Immunogenetics and Transplant Biology Unit, Città della Salute e della Scienza Hospital, Turin 10126, Italy
| | - Maria Luca
- Department of Medical Sciences, University of Turin, Turin 10126, Italy
- Immunogenetics and Transplant Biology Unit, Città della Salute e della Scienza Hospital, Turin 10126, Italy
| | - Carmelo Romeo
- Department of Medical Sciences, University of Turin, Turin 10126, Italy
- Immunogenetics and Transplant Biology Unit, Città della Salute e della Scienza Hospital, Turin 10126, Italy
| | - Fiorenza Mioli
- Department of Medical Sciences, University of Turin, Turin 10126, Italy
- Immunogenetics and Transplant Biology Unit, Città della Salute e della Scienza Hospital, Turin 10126, Italy
| | | | - Daniele Tessaris
- Department of Public Health and Pediatric Sciences, University of Torino, Torino 10126, Italy
- Pediatric Endocrinology, Regina Margherita Childrens' Hospital, Torino 10126, Italy
| | - Diana Carli
- Department of Medical Sciences, University of Turin, Turin 10126, Italy
- Immunogenetics and Transplant Biology Unit, Città della Salute e della Scienza Hospital, Turin 10126, Italy
| | - Antonio Amoroso
- Department of Medical Sciences, University of Turin, Turin 10126, Italy
- Immunogenetics and Transplant Biology Unit, Città della Salute e della Scienza Hospital, Turin 10126, Italy
| | - Tiziana Vaisitti
- Department of Medical Sciences, University of Turin, Turin 10126, Italy
- Immunogenetics and Transplant Biology Unit, Città della Salute e della Scienza Hospital, Turin 10126, Italy
| | - Luisa De Sanctis
- Department of Public Health and Pediatric Sciences, University of Torino, Torino 10126, Italy
- Pediatric Endocrinology, Regina Margherita Childrens' Hospital, Torino 10126, Italy
| | - Silvia Deaglio
- Department of Medical Sciences, University of Turin, Turin 10126, Italy
- Immunogenetics and Transplant Biology Unit, Città della Salute e della Scienza Hospital, Turin 10126, Italy
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Thompson MD, Percy ME, Cole DEC, Bichet DG, Hauser AS, Gorvin CM. G protein-coupled receptor (GPCR) gene variants and human genetic disease. Crit Rev Clin Lab Sci 2024:1-30. [PMID: 38497103 DOI: 10.1080/10408363.2023.2286606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 11/19/2023] [Indexed: 03/19/2024]
Abstract
Genetic variations in the genes encoding G protein-coupled receptors (GPCRs) can disrupt receptor structure and function, which can result in human genetic diseases. Disease-causing mutations have been reported in at least 55 GPCRs for more than 66 monogenic diseases in humans. The spectrum of pathogenic and likely pathogenic variants includes loss of function variants that decrease receptor signaling on one extreme and gain of function that may result in biased signaling or constitutive activity, originally modeled on prototypical rhodopsin GPCR variants identified in retinitis pigmentosa, on the other. GPCR variants disrupt ligand binding, G protein coupling, accessory protein function, receptor desensitization and receptor recycling. Next generation sequencing has made it possible to identify variants of uncertain significance (VUS). We discuss variants in receptors known to result in disease and in silico strategies for disambiguation of VUS such as sorting intolerant from tolerant and polymorphism phenotyping. Modeling of variants has contributed to drug development and precision medicine, including drugs that target the melanocortin receptor in obesity and interventions that reverse loss of gonadotropin-releasing hormone receptor from the cell surface in idiopathic hypogonadotropic hypogonadism. Activating and inactivating variants of the calcium sensing receptor (CaSR) gene that are pathogenic in familial hypocalciuric hypercalcemia and autosomal dominant hypocalcemia have enabled the development of calcimimetics and calcilytics. Next generation sequencing has continued to identify variants in GPCR genes, including orphan receptors, that contribute to human phenotypes and may have therapeutic potential. Variants of the CaSR gene, some encoding an arginine-rich region that promotes receptor phosphorylation and intracellular retention, have been linked to an idiopathic epilepsy syndrome. Agnostic strategies have identified variants of the pyroglutamylated RF amide peptide receptor gene in intellectual disability and G protein-coupled receptor 39 identified in psoriatic arthropathy. Coding variants of the G protein-coupled receptor L1 (GPR37L1) orphan receptor gene have been identified in a rare familial progressive myoclonus epilepsy. The study of the role of GPCR variants in monogenic, Mendelian phenotypes has provided the basis of modeling the significance of more common variants of pharmacogenetic significance.
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Affiliation(s)
- Miles D Thompson
- Krembil Brain Institute, Toronto Western Hospital, Toronto, ON, Canada
| | - Maire E Percy
- Departments of Physiology and Obstetrics & Gynaecology, University of Toronto, Toronto, ON, Canada
| | - David E C Cole
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Daniel G Bichet
- Department of Physiology and Medicine, Hôpital du Sacré-Coeur, Université de Montréal, QC, Canada
| | - Alexander S Hauser
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Caroline M Gorvin
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, Birmingham, West Midlands, UK
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English KA, Lines KE, Thakker RV. Genetics of hereditary forms of primary hyperparathyroidism. Hormones (Athens) 2024; 23:3-14. [PMID: 38038882 PMCID: PMC10847196 DOI: 10.1007/s42000-023-00508-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Accepted: 11/07/2023] [Indexed: 12/02/2023]
Abstract
Primary hyperparathyroidism (PHPT), a relatively common disorder characterized by hypercalcemia with raised or inappropriately normal serum parathyroid hormone (PTH) concentrations, may occur as part of a hereditary syndromic disorder or as a non-syndromic disease. The associated syndromic disorders include multiple endocrine neoplasia types 1-5 (MEN1-5) and hyperparathyroidism with jaw tumor (HPT-JT) syndromes, and the non-syndromic forms include familial hypocalciuric hypercalcemia types 1-3 (FHH1-3), familial isolated hyperparathyroidism (FIHP), and neonatal severe hyperparathyroidism (NS-HPT). Such hereditary forms may occur in > 10% of patients with PHPT, and their recognition is important for implementation of gene-specific screening protocols and investigations for other associated tumors. Syndromic PHPT tends to be multifocal and multiglandular with most patients requiring parathyroidectomy with the aim of limiting end-organ damage associated with hypercalcemia, particularly osteoporosis, nephrolithiasis, and renal failure. Some patients with non-syndromic PHPT may have mutations of the MEN1 gene or the calcium-sensing receptor (CASR), whose loss of function mutations usually cause FHH1, a disorder associated with mild hypercalcemia and may follow a benign clinical course. Measurement of the urinary calcium-to-creatinine ratio clearance (UCCR) may help to distinguish patients with FHH from those with PHPT, as the majority of FHH patients have low urinary calcium excretion (UCCR < 0.01). Once genetic testing confirms a hereditary cause of PHPT, further genetic testing can be offered to the patients' relatives and subsequent screening can be carried out in these affected family members, which prevents inappropriate testing in normal individuals.
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Affiliation(s)
- Katherine A English
- OCDEM, Radcliffe Department of Medicine, Churchill Hospital, University of Oxford, Oxford, OX3 7LJ, UK
| | - Kate E Lines
- OCDEM, Radcliffe Department of Medicine, Churchill Hospital, University of Oxford, Oxford, OX3 7LJ, UK
- Oxford NIHR Biomedical Research Centre, Oxford University Hospitals Trust, Oxford, OX3 7LE, UK
| | - Rajesh V Thakker
- OCDEM, Radcliffe Department of Medicine, Churchill Hospital, University of Oxford, Oxford, OX3 7LJ, UK.
- Oxford NIHR Biomedical Research Centre, Oxford University Hospitals Trust, Oxford, OX3 7LE, UK.
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7
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Lin CM, Ding YX, Huang SM, Chen YC, Lee HJ, Sung CC, Lin SH. Identification and characterization of a novel CASR mutation causing familial hypocalciuric hypercalcemia. Front Endocrinol (Lausanne) 2024; 15:1291160. [PMID: 38487341 PMCID: PMC10937390 DOI: 10.3389/fendo.2024.1291160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 01/22/2024] [Indexed: 03/17/2024] Open
Abstract
Context Although a monoallelic mutation in the calcium-sensing receptor (CASR) gene causes familial hypocalciuric hypercalcemia (FHH), the functional characterization of the identified CASR mutation linked to the clinical response to calcimimetics therapy is still limited. Objective A 45-year-old male presenting with moderate hypercalcemia, hypocalciuria, and inappropriately high parathyroid hormone (PTH) had a good response to cinacalcet (total serum calcium (Ca2+) from 12.5 to 10.1 mg/dl). We identified the genetic mutation and characterized the functional and pathophysiological mechanisms, and then linked the mutation to calcimimetics treatment in vitro. Design Sanger sequencing of the CASR, GNA11, and AP2S1 genes was performed in his family. The simulation model was used to predict the function of the identified mutant. In vitro studies, including immunoblotting, immunofluorescence, a cycloheximide chase study, Calbryte™ 520 Ca2+ detection, and half-maximal effective concentration (EC50), were examined. Results This proband was found to carry a de novo heterozygous missense I554N in the cysteine-rich domain of CASR, which was pathogenic based on the different software prediction models and ACGME criteria. The simulation model showed that CASR I554N mutation decreased its binding energy with Ca2+. Human CASR I554N mutation attenuated the stability of CASR protein, reduced the expression of p-ERK 1/2, and blunted the intracellular Ca2+ response to gradient extracellular Ca2+ (eCa2+) concentration. The EC50 study also demonstrated the correctable effect of calcimimetics on the function of the CASR I554N mutation. Conclusion This novel CASR I554N mutation causing FHH attenuates CASR stability, its binding affinity with Ca2+, and the response to eCa2+ corrected by therapeutic calcimimetics.
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Affiliation(s)
- Chien-Ming Lin
- Department of Pediatrics, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Yi-Xuan Ding
- Department of Pediatrics, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Shih-Ming Huang
- Department of Biochemistry, National Defense Medical Center, Taipei, Taiwan
| | - Ying-Chuan Chen
- Department of Physiology and Biophysics, National Defense Medical Center, Taipei, Taiwan
| | - Hwei-Jen Lee
- Department of Biochemistry, National Defense Medical Center, Taipei, Taiwan
| | - Chih-Chien Sung
- Division of Nephrology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Shih-Hua Lin
- Division of Nephrology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
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Mathew A, Bhagavaldas MC, Biswas R, Biswas L. Genetic risk factors in ankylosing spondylitis: Insights into etiology and disease pathogenesis. Int J Rheum Dis 2024; 27:e15023. [PMID: 38151980 DOI: 10.1111/1756-185x.15023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 11/07/2023] [Accepted: 12/18/2023] [Indexed: 12/29/2023]
Affiliation(s)
- Ashlin Mathew
- Centre for Nanosciences and Molecular Medicine, Amrita Vishwa Vidyapeetham, Kochi, India
| | | | - Raja Biswas
- Centre for Nanosciences and Molecular Medicine, Amrita Vishwa Vidyapeetham, Kochi, India
| | - Lalitha Biswas
- Centre for Nanosciences and Molecular Medicine, Amrita Vishwa Vidyapeetham, Kochi, India
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Tscherrig D, Bhardwaj R, Biner D, Dernič J, Ross-Kaschitza D, Peinelt C, Hediger MA, Lochner M. Development of chemical tools based on GSK-7975A to study store-operated calcium entry in cells. Cell Calcium 2024; 117:102834. [PMID: 38006628 DOI: 10.1016/j.ceca.2023.102834] [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: 08/07/2023] [Revised: 11/11/2023] [Accepted: 11/13/2023] [Indexed: 11/27/2023]
Abstract
Many physiological functions, such as cell differentiation, proliferation, muscle contraction, neurotransmission and fertilisation, are regulated by changes of Ca2+ levels. The major Ca2+ store in cells is the endoplasmic reticulum (ER). Certain cellular processes induce ER store depletion, e.g. by activating IP3 receptors, that in turn induces a store refilling process known as store-operated calcium entry (SOCE). This refilling process entails protein-protein interactions between Ca2+ sensing stromal interaction molecules (STIM) in the ER membrane and Orai proteins in the plasma membrane. Fully assembled STIM/Orai complexes then form highly selective Ca2+ channels called Ca2+ release-activated Ca2+ Channels (CRAC) through which Ca2+ ions flow into the cytosol and subsequently are pumped into the ER by the sarcoplasmic/endoplasmic reticulum calcium ATPase (SERCA). Abnormal SOCE has been associated with numerous human diseases and cancers, and therefore key players STIM and Orai have attracted significant therapeutic interest. Several potent experimental and clinical candidate compounds have been developed and have helped to study SOCE in various cell types. We have synthesized multiple novel small-molecule probes based on the known SOCE inhibitor GSK-7975A. Here we present GSK-7975A derivatives, which feature photo-caging, photo-crosslinking, biotin and clickable moieties, and also contain deuterium labels. Evaluation of these GSK-7975A probes using a fluorometric imaging plate reader (FLIPR)-Tetra-based Ca2+ imaging assay showed that most synthetic modifications did not have a detrimental impact on the SOCE inhibitory activity. The photo-caged GSK-7975A was also used in patch-clamp electrophysiology experiments. In summary, we have developed a number of active, GSK-7975A-based molecular probes that have interesting properties and therefore are useful experimental tools to study SOCE in various cells and settings.
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Affiliation(s)
- Dominic Tscherrig
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bühlstrasse 28, 3012 Bern, Switzerland
| | - Rajesh Bhardwaj
- Department of BioMedical Research, University of Bern and Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, Freiburgstrasse 15, 3010 Bern, Switzerland.
| | - Daniel Biner
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Jan Dernič
- Department of BioMedical Research, University of Bern and Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, Freiburgstrasse 15, 3010 Bern, Switzerland
| | - Daniela Ross-Kaschitza
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bühlstrasse 28, 3012 Bern, Switzerland
| | - Christine Peinelt
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bühlstrasse 28, 3012 Bern, Switzerland
| | - Matthias A Hediger
- Department of BioMedical Research, University of Bern and Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, Freiburgstrasse 15, 3010 Bern, Switzerland.
| | - Martin Lochner
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bühlstrasse 28, 3012 Bern, Switzerland.
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10
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Butylina M, Föger-Samwald U, Gelles K, Pietschmann P, Sipos W. Challenges in establishing animal models for studying osteoimmunology of hypoparathyroidism. Front Vet Sci 2023; 10:1163903. [PMID: 37180074 PMCID: PMC10169642 DOI: 10.3389/fvets.2023.1163903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Accepted: 03/30/2023] [Indexed: 05/15/2023] Open
Abstract
Hypoparathyroidism is a relatively rare human and veterinary disease characterized by deficient or absent production of parathyroid hormone (PTH). PTH is known as a classical regulator of calcium and phosphorus homeostasis. Nevertheless, the hormone also appears to modulate immune functions. For example, increased CD4:CD8 T-cell ratios and elevated interleukin (IL)-6 and IL-17A levels were observed in patients with hyperparathyroidism, whereas gene expression of tumor necrosis factor-α (TNF-α) and granulocyte macrophage-colony stimulating factor (GM-CSF) was decreased in patients with chronic postsurgical hypoparathyroidism. Various immune cell populations are affected differently. So, there is a need for validated animal models for the further characterization of this disease for identifying targeted immune-modulatory therapies. In addition to genetically modified mouse models of hypoparathyroidism, there are surgical rodent models. Parathyroidectomy (PTX) can be well performed in rats-for pharmacological and associated osteoimmunological research and bone mechanical studies, a large animal model could be preferable, however. A major drawback for successfully performing total PTX in large animal species (pigs and sheep) is the presence of accessory glands, thus demanding to develop new approaches for real-time detection of all parathyroid tissues.
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Affiliation(s)
- Maria Butylina
- Institute of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Ursula Föger-Samwald
- Institute of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Katharina Gelles
- Institute of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Peter Pietschmann
- Institute of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Wolfgang Sipos
- Clinical Department for Farm Animals, University of Veterinary Medicine Vienna, Vienna, Austria
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Chinoy A, Nicholson J, Skae M, Hannan FM, Thakker RV, Mughal MZ, Padidela R. Neurodevelopmental Abnormalities in Patients with Familial Hypocalciuric Hypercalcemia Type 3. J Pediatr 2023:S0022-3476(23)00126-9. [PMID: 36868303 DOI: 10.1016/j.jpeds.2023.02.013] [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: 09/21/2022] [Revised: 12/26/2022] [Accepted: 02/24/2023] [Indexed: 03/05/2023]
Abstract
OBJECTIVES To evaluate the prevalence and degree of any neurodevelopmental abnormalities in children with familial hypocalciuric hypercalcemia type 3 (FHH3). STUDY DESIGN A formal neurodevelopmental assessment was performed in children diagnosed with FHH3. The Vineland Adaptive Behavior Scales, which is a standardized parent report assessment tool for adaptive behavior, was used to assess communication, social skills, and motor function and to generate a composite score. RESULTS Six patients were diagnosed with hypercalcemia between 0.1 and 8 years of age. All had neurodevelopmental abnormalities in childhood consisting of either global developmental delay, motor delay, expressive speech disturbances, learning difficulties, hyperactivity, or autism spectrum disorder. Four out of the 6 probands had a composite Vineland Adaptive Behavior Scales SDS of < -2.0, indicating adaptive malfunctioning. Significant deficits were observed in the domains of communication (mean SDS: -2.0, P < .01), social skills (mean SDS: -1.3, P < .05), and motor skills (mean SDS: 2.6, P < .05). Individuals were equally affected across domains, with no clear genotype-phenotype correlation. All family members affected with FHH3 also described evidence of neurodevelopmental dysfunction, including mild-to-moderate learning difficulties, dyslexia, and hyperactivity. CONCLUSION Neurodevelopmental abnormalities appear to be a highly penetrant and common feature of FHH3, and early detection is warranted to provide appropriate educational support. This case series also supports consideration of serum calcium measurement as part of the diagnostic work-up in any child presenting with unexplained neurodevelopmental abnormalities.
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Affiliation(s)
- Amish Chinoy
- Paediatric Endocrine Department, Royal Manchester Children's Hospital, Manchester, United Kingdom; Faculty of Biology, Medicine & Health, University of Manchester, Manchester, United Kingdom.
| | - Jacqueline Nicholson
- Paediatric Psychosocial Department, Royal Manchester Children's Hospital, Manchester, United Kingdom
| | - Mars Skae
- Paediatric Endocrine Department, Royal Manchester Children's Hospital, Manchester, United Kingdom; Faculty of Biology, Medicine & Health, University of Manchester, Manchester, United Kingdom
| | - Fadil M Hannan
- Nuffield Department of Women's & Reproductive Health, University of Oxford, Oxford, United Kingdom
| | - Rajesh V Thakker
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom; NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - M Zulf Mughal
- Paediatric Endocrine Department, Royal Manchester Children's Hospital, Manchester, United Kingdom; Faculty of Biology, Medicine & Health, University of Manchester, Manchester, United Kingdom
| | - Raja Padidela
- Paediatric Endocrine Department, Royal Manchester Children's Hospital, Manchester, United Kingdom; Faculty of Biology, Medicine & Health, University of Manchester, Manchester, United Kingdom
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Iamartino L, Brandi ML. The calcium-sensing receptor in inflammation: Recent updates. Front Physiol 2022; 13:1059369. [PMID: 36467702 PMCID: PMC9716066 DOI: 10.3389/fphys.2022.1059369] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Accepted: 11/07/2022] [Indexed: 07/30/2023] Open
Abstract
The Calcium-Sensing Receptor (CaSR) is a member of the class C of G-proteins coupled receptors (GPCRs), it plays a pivotal role in calcium homeostasis by directly controlling calcium excretion in the kidneys and indirectly by regulating parathyroid hormone (PTH) release from the parathyroid glands. The CaSR is found to be ubiquitously expressed in the body, playing a plethora of additional functions spanning from fluid secretion, insulin release, neuronal development, vessel tone to cell proliferation and apoptosis, to name but a few. The present review aims to elucidate and clarify the emerging regulatory effects that the CaSR plays in inflammation in several tissues, where it mostly promotes pro-inflammatory responses, with the exception of the large intestine, where contradictory roles have been recently reported. The CaSR has been found to be expressed even in immune cells, where it stimulates immune response and chemokinesis. On the other hand, CaSR expression seems to be boosted under inflammatory stimulus, in particular, by pro-inflammatory cytokines. Because of this, the CaSR has been addressed as a key factor responsible for hypocalcemia and low levels of PTH that are commonly found in critically ill patients under sepsis or after burn injury. Moreover, the CaSR has been found to be implicated in autoimmune-hypoparathyroidism, recently found also in patients treated with immune-checkpoint inhibitors. Given the tight bound between the CaSR, calcium and vitamin D metabolism, we also speculate about their roles in the pathogenesis of severe acute respiratory syndrome coronavirus-19 (SARS-COVID-19) infection and their impact on patients' prognosis. We will further explore the therapeutic potential of pharmacological targeting of the CaSR for the treatment and management of aberrant inflammatory responses.
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Affiliation(s)
- Luca Iamartino
- Department of Experimental Clinical and Biomedical Sciences “Mario Serio”, University of Florence, Florence, Italy
| | - Maria Luisa Brandi
- F.I.R.M.O. (Italian Foundation for the Research on Bone Diseases), Florence, Italy
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13
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Minisola S, Arnold A, Belaya Z, Brandi ML, Clarke BL, Hannan FM, Hofbauer LC, Insogna KL, Lacroix A, Liberman U, Palermo A, Pepe J, Rizzoli R, Wermers R, Thakker RV. Epidemiology, Pathophysiology, and Genetics of Primary Hyperparathyroidism. J Bone Miner Res 2022; 37:2315-2329. [PMID: 36245271 PMCID: PMC10092691 DOI: 10.1002/jbmr.4665] [Citation(s) in RCA: 47] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 07/18/2022] [Accepted: 07/29/2022] [Indexed: 11/11/2022]
Abstract
In this narrative review, we present data gathered over four decades (1980-2020) on the epidemiology, pathophysiology and genetics of primary hyperparathyroidism (PHPT). PHPT is typically a disease of postmenopausal women, but its prevalence and incidence vary globally and depend on a number of factors, the most important being the availability to measure serum calcium and parathyroid hormone levels for screening. In the Western world, the change in presentation to asymptomatic PHPT is likely to occur, over time also, in Eastern regions. The selection of the population to be screened will, of course, affect the epidemiological data (ie, general practice as opposed to tertiary center). Parathyroid hormone has a pivotal role in regulating calcium homeostasis; small changes in extracellular Ca++ concentrations are detected by parathyroid cells, which express calcium-sensing receptors (CaSRs). Clonally dysregulated overgrowth of one or more parathyroid glands together with reduced expression of CaSRs is the most important pathophysiologic basis of PHPT. The spectrum of skeletal disease reflects different degrees of dysregulated bone remodeling. Intestinal calcium hyperabsorption together with increased bone resorption lead to increased filtered load of calcium that, in addition to other metabolic factors, predispose to the appearance of calcium-containing kidney stones. A genetic basis of PHPT can be identified in about 10% of all cases. These may occur as a part of multiple endocrine neoplasia syndromes (MEN1-MEN4), or the hyperparathyroidism jaw-tumor syndrome, or it may be caused by nonsyndromic isolated endocrinopathy, such as familial isolated PHPT and neonatal severe hyperparathyroidism. DNA testing may have value in: confirming the clinical diagnosis in a proband; eg, by distinguishing PHPT from familial hypocalciuric hypercalcemia (FHH). Mutation-specific carrier testing can be performed on a proband's relatives and identify where the proband is a mutation carrier, ruling out phenocopies that may confound the diagnosis; and potentially prevention via prenatal/preimplantation 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)
- Salvatore Minisola
- Department of Clinical, Internal, Anaesthesiologic and Cardiovascular Sciences, 'Sapienza', Rome University, Rome, Italy
| | - Andrew Arnold
- Center for Molecular Oncology and Division of Endocrinology & Metabolism, University of Connecticut School of Medicine, Farmington, CT, USA
| | - Zhanna Belaya
- Department of Neuroendocrinology and Bone Disease, The National Medical Research Centre for Endocrinology, Moscow, Russia
| | - Maria Luisa Brandi
- F.I.R.M.O. Italian Foundation for the Research on Bone Diseases, Florence, Italy
| | - Bart L Clarke
- Mayo Clinic Division of Endocrinology, Diabetes, Metabolism, and Nutrition, Mayo Clinic, Rochester, MN, USA
| | - Fadil M Hannan
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), Churchill Hospital, Oxford, UK.,Nuffield Department of Women's & Reproductive Health, University of Oxford, Oxford, UK
| | - Lorenz C Hofbauer
- Division of Endocrinology, Diabetes, and Bone Diseases & Center for Healthy Aging, Technische Universität Dresden, Dresden, Germany
| | - Karl L Insogna
- Yale Bone Center Yale School of Medicine, Yale University, New Haven, CT, USA
| | - André Lacroix
- Division of Endocrinology, Department of Medicine and Research Center, Centre Hospitalier de l'Université de Montréal (CHUM), Montréal, Canada
| | - Uri Liberman
- Department of Physiology and Pharmacology, Tel Aviv University School of Medicine, Tel Aviv, Israel
| | - Andrea Palermo
- Unit of Metabolic Bone and Thyroid Disorders, Fondazione Policlinico Universitario Campus Bio-Medico and Unit of Endocrinology and Diabetes, Campus Bio-Medico University, Rome, Italy
| | - Jessica Pepe
- Department of Clinical, Internal, Anaesthesiologic and Cardiovascular Sciences, 'Sapienza', Rome University, Rome, Italy
| | - René Rizzoli
- Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland
| | - Robert Wermers
- Division of Endocrinology, Diabetes, Metabolism, and Nutrition and Department of Medicine, Mayo Clinic, Rochester, MN, USA
| | - Rajesh V Thakker
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), Churchill Hospital, Oxford, UK.,Oxford National Institute for Health Research (NIHR) Biomedical Research Centre, Oxford University Hospitals NHS Foundation Trust, John Radcliffe Hospital, Oxford, UK
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14
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Newey PJ, Hannan FM, Wilson A, Thakker RV. Genetics of monogenic disorders of calcium and bone metabolism. Clin Endocrinol (Oxf) 2022; 97:483-501. [PMID: 34935164 PMCID: PMC7614875 DOI: 10.1111/cen.14644] [Citation(s) in RCA: 2] [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: 08/31/2021] [Revised: 10/24/2021] [Accepted: 11/07/2021] [Indexed: 12/19/2022]
Abstract
Disorders of calcium homeostasis are the most frequent metabolic bone and mineral disease encountered by endocrinologists. These disorders usually manifest as primary hyperparathyroidism (PHPT) or hypoparathyroidism (HP), which have a monogenic aetiology in 5%-10% of cases, and may occur as an isolated endocrinopathy, or as part of a complex syndrome. The recognition and diagnosis of these disorders is important to facilitate the most appropriate management of the patient, with regard to both the calcium-related phenotype and any associated clinical features, and also to allow the identification of other family members who may be at risk of disease. Genetic testing forms an important tool in the investigation of PHPT and HP patients and is usually reserved for those deemed to be an increased risk of a monogenic disorder. However, identifying those suitable for testing requires a thorough clinical evaluation of the patient, as well as an understanding of the diversity of relevant phenotypes and their genetic basis. This review aims to provide an overview of the genetic basis of monogenic metabolic bone and mineral disorders, primarily focusing on those associated with abnormal calcium homeostasis, and aims to provide a practical guide to the implementation of genetic testing in the clinic.
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Affiliation(s)
- Paul J Newey
- Division of Molecular and Clinical Medicine, Ninewells Hospital & Medical School, University of Dundee, Scotland, UK
| | - Fadil M Hannan
- Nuffield Department of Women's and Reproductive Health, University of Oxford, Oxford, UK
| | - Abbie Wilson
- Division of Molecular and Clinical Medicine, Ninewells Hospital & Medical School, University of Dundee, Scotland, UK
| | - Rajesh V Thakker
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology & Metabolism (OCDEM), Churchill Hospital, University of Oxford, Oxford, UK
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15
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Roszko KL, Stapleton Smith LM, Sridhar AV, Roberts MS, Hartley IR, Gafni RI, Collins MT, Fox JC, Nemeth EF. Autosomal Dominant Hypocalcemia Type 1: A Systematic Review. J Bone Miner Res 2022; 37:1926-1935. [PMID: 35879818 PMCID: PMC9805030 DOI: 10.1002/jbmr.4659] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 07/14/2022] [Accepted: 07/20/2022] [Indexed: 01/07/2023]
Abstract
Autosomal dominant hypocalcemia type 1 (ADH1) is a rare form of hypoparathyroidism due to activating variants of the calcium-sensing receptor gene (CASR). Inherited or de novo activating variants of the CASR alter the set point for extracellular calcium, resulting in inadequate parathyroid hormone (PTH) secretion and inappropriate renal calcium excretion leading to hypocalcemia and hypercalciuria. Conventional therapy includes calcium and activated vitamin D, which can worsen hypercalciuria, resulting in renal complications. A systematic literature review, using published reports from 1994 to 2021, was conducted to catalog CASR variants, to define the ADH1 clinical spectrum, and to determine the effect of treatment on patients with ADH1. There were 113 unique CASR variants reported, with a general lack of genotype/phenotype correlation. Clinical data were available in 191 patients; 27% lacked symptoms, 32% had mild/moderate symptoms, and 41% had severe symptoms. Seizures, the most frequent clinical presentation, occurred in 39% of patients. In patients with blood and urine chemistries available at the time of diagnosis (n = 91), hypocalcemia (99%), hyperphosphatemia (59%), low PTH levels (57%), and hypercalciuria (34%) were observed. Blood calcium levels were significantly lower in patients with severe symptoms compared with asymptomatic patients (6.8 ± 0.7 versus 7.6 ± 0.7 mg/dL [mean ± SD]; p < 0.0001), and the age of presentation was significantly lower in severely symptomatic patients (9.1 ± 15.0 versus 19.3 ± 19.4 years; p < 0.01). Assessments for complications including nephrocalcinosis, nephrolithiasis, renal impairment, and brain calcifications in 57 patients on conventional therapy showed that 75% had at least one complication. Hypercalciuria was associated with nephrocalcinosis, nephrolithiasis, renal impairment, or brain calcifications (odds ratio [OR] = 9.3; 95% confidence interval [CI] 2.4-37.2; p < 0.01). In 27 patients with urine calcium measures before and after starting conventional therapy, the incidence of hypercalciuria increased by 91% (p < 0.05) after therapy initiation. ADH1 is a condition often associated with severe symptomatology at presentation with an increase in the risk of renal complications after initiation of conventional therapy. © 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)
- Kelly L Roszko
- Skeletal Disorders & Mineral Homeostasis Section, NIDCR, NIH, Bethesda, MD, USA
| | | | | | | | - Iris R Hartley
- Skeletal Disorders & Mineral Homeostasis Section, NIDCR, NIH, Bethesda, MD, USA
| | - Rachel I Gafni
- Skeletal Disorders & Mineral Homeostasis Section, NIDCR, NIH, Bethesda, MD, USA
| | - Michael T Collins
- Skeletal Disorders & Mineral Homeostasis Section, NIDCR, NIH, Bethesda, MD, USA
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16
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Goolam MA, Brown AP, Edwards KT, Gregory KJ, Leach K, Conigrave AD. Cell Surface Calcium-Sensing Receptor Heterodimers: Mutant Gene Dosage Affects Ca 2+ Sensing but Not G Protein Interaction. J Bone Miner Res 2022; 37:1787-1807. [PMID: 35848051 PMCID: PMC9545990 DOI: 10.1002/jbmr.4651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 06/20/2022] [Accepted: 07/14/2022] [Indexed: 11/20/2022]
Abstract
The calcium-sensing receptor is a homodimeric class C G protein-coupled receptor (GPCR) that senses extracellular Ca2+ (Ca2+ o ) via a dimeric extracellular Venus flytrap (VFT) unit that activates G protein-dependent signaling via twin Cysteine-rich domains linked to transmembrane heptahelical (HH) bundles. It plays a key role in the regulation of human calcium and thus mineral metabolism. However, the nature of interactions between VFT units and HH bundles, and the impacts of heterozygous or homozygous inactivating mutations, which have implications for disorders of calcium metabolism are not yet clearly defined. Herein we generated CaSR-GABAB1 and CaSR-GABAB2 chimeras subject to GABAB -dependent endoplasmic reticulum sorting to traffic mutant heterodimers to the cell surface. Transfected HEK-293 cells were assessed for Ca2+ o -stimulated Ca2+ i mobilization using mutations in either the VFT domains and/or HH bundle intraloop-2 or intraloop-3. When the same mutation was present in both VFT domains of receptor dimers, analogous to homozygous neonatal severe hyperparathyroidism (NSHPT), receptor function was markedly impaired. Mutant heterodimers containing one wild-type (WT) and one mutant VFT domain, however, corresponding to heterozygous familial hypocalciuric hypercalcemia type-1 (FHH-1), supported maximal signaling with reduced Ca2+ o potency. Thus two WT VFT domains were required for normal Ca2+ o potency and there was a pronounced gene-dosage effect. In contrast, a single WT HH bundle was insufficient for maximal signaling and there was no functional difference between heterodimers in which the mutation was present in one or both intraloops; ie, no gene-dosage effect. Finally, we observed that the Ca2+ o -stimulated CaSR operated exclusively via signaling in-trans and not via combined in-trans and in-cis signaling. We consider how receptor asymmetry may support the underlying mechanisms. © 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)
- Mahvash A Goolam
- School of Life and Environmental Sciences, Charles Perkins Centre (D17), University of Sydney, NSW, Australia
| | - Alice P Brown
- School of Life and Environmental Sciences, Charles Perkins Centre (D17), University of Sydney, NSW, Australia
| | - Kimberly T Edwards
- School of Life and Environmental Sciences, Charles Perkins Centre (D17), University of Sydney, NSW, Australia
| | - Karen J Gregory
- Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia
| | - Katie Leach
- Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia
| | - Arthur D Conigrave
- School of Life and Environmental Sciences, Charles Perkins Centre (D17), University of Sydney, NSW, Australia
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17
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Wang L, Zhou Z, Yang Y, Gao P, Lin X, Wu Z. A Genetic Polymorphism in the WDR72 Gene is Associated With Calcium Nephrolithiasis in the Chinese Han Population. Front Genet 2022; 13:897051. [PMID: 35910217 PMCID: PMC9333346 DOI: 10.3389/fgene.2022.897051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 06/24/2022] [Indexed: 12/02/2022] Open
Abstract
A previous genome-wide association study (GWAS) reported several novel loci for nephrolithiasis in British and Japanese population, some of which were predicted to influence CaSR signaling. In this study, we aimed to evaluate the association of these loci with calcium nephrolithiasis in Chinese Han population. We performed a case-control association analysis involving 691 patients with calcium nephrolithiasis and 1008 control subjects. We were able to genotype a total of 17 single-nucleotide polymorphisms (SNPs), which were previously reported to be significantly associated with nephrolithiasis in GWAS. rs578595 at WDR72 was significantly associated with calcium nephrolithiasis in Chinese Han population (p < 0.001, OR = 0.617). Moreover, rs12654812 at SLC34A1 (p = 0.0427, OR = 1.170), rs12539707 at HIBADH (p = 0.0179, OR = 0.734), rs1037271 at DGKH (p = 0.0096, OR = 0.828) and rs12626330 at CLDN14 (p = 0.0080, OR = 1.213) indicated suggestive associations with calcium nephrolithiasis. Our results elucidated the significance of genetic variation at WDR72, DGKH, CLDN14, SLC34A1, and HIBADH in Chinese patients with nephrolithiasis. Since polymorphisms of WDR72, DGKH, and CLDN14 are predicted to influence in CaSR signaling, our results emphasized the role of abnormal calcium homeostasis in calcium nephrolithiasis.
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Affiliation(s)
- Lujia Wang
- Department of Urology, Huashan Hospital & Institute of Urology, Fudan University, Shanghai, China
- Clinical Research Center of Urolithiasis, Shanghai Medical College, Fudan University, Shanghai, China
| | - Zijian Zhou
- Department of Urology, Huashan Hospital & Institute of Urology, Fudan University, Shanghai, China
- Clinical Research Center of Urolithiasis, Shanghai Medical College, Fudan University, Shanghai, China
| | - Yuanyuan Yang
- Department of Urology, Huashan Hospital & Institute of Urology, Fudan University, Shanghai, China
- Clinical Research Center of Urolithiasis, Shanghai Medical College, Fudan University, Shanghai, China
| | - Peng Gao
- Department of Urology, Huashan Hospital & Institute of Urology, Fudan University, Shanghai, China
- Clinical Research Center of Urolithiasis, Shanghai Medical College, Fudan University, Shanghai, China
| | - Xiaoling Lin
- Department of Urology, Shanghai Children’s Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- *Correspondence: Xiaoling Lin, ; Zhong Wu,
| | - Zhong Wu
- Department of Urology, Huashan Hospital & Institute of Urology, Fudan University, Shanghai, China
- Clinical Research Center of Urolithiasis, Shanghai Medical College, Fudan University, Shanghai, China
- *Correspondence: Xiaoling Lin, ; Zhong Wu,
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Guha S, Majumder K. Comprehensive Review of γ-Glutamyl Peptides (γ-GPs) and Their Effect on Inflammation Concerning Cardiovascular Health. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:7851-7870. [PMID: 35727887 DOI: 10.1021/acs.jafc.2c01712] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
γ-Glutamyl peptides (γ-GPs) are a group of peptides naturally found in various food sources. The unique γ-bond potentially enables them to resist gastrointestinal digestion and offers high stability in vivo with a longer half-life. In recent years, these peptides have caught researchers' attention due to their ability to impart kokumi taste and elicit various physiological functions via the allosteric activation of the calcium-sensing receptor (CaSR). This review discusses the various food sources of γ-glutamyl peptides, different synthesis modes, allosteric activation of CaSR for taste perception, and associated multiple biological functions they can exhibit, with a special emphasis on their role in modulating chronic inflammation concerning cardiovascular health.
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Affiliation(s)
- Snigdha Guha
- Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States
| | - Kaustav Majumder
- Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States
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19
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Sviridonova MA. [Syndrome of hypocalсiuric hypercalcemia. Is it rare? Two clinical cases in an outpatient clinic]. PROBLEMY ENDOKRINOLOGII 2022; 68:24-31. [PMID: 36337015 DOI: 10.14341/probl13125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 06/17/2022] [Accepted: 06/17/2022] [Indexed: 11/09/2022]
Abstract
Hypocalciuric hypercalcemia syndrome (familial hypocalciuric hypercalcemia, FHH) is an inherited condition based on dysfunction of the calcium receptor or its associated partner proteins. Recent evidence suggests that the prevalence of this condition may be comparable to that of primary hyperparathyroidism. Clinical manifestations of FHH are usually absent; however the classic symptoms of hypercalcemia may be present in some cases. Timely differential diagnosis of FHH avoids unnecessary and expensive instrumental examination, as well as ineffective treatment. The clinical cases presented in this publication demonstrate the unjustified difficulties in this issue and the necessity to raise the awareness of physicians about the familial hypocalciuric hypercalcemia.
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Disorders of the Calcium Sensing Signaling Pathway: From Familial Hypocalciuric Hypercalcemia (FHH) to Life Threatening Conditions in Infancy. J Clin Med 2022; 11:jcm11092595. [PMID: 35566721 PMCID: PMC9100033 DOI: 10.3390/jcm11092595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 04/29/2022] [Accepted: 05/01/2022] [Indexed: 11/23/2022] Open
Abstract
Familial hypocalciuric hypercalcemia (FHH) is a mostly benign condition of elevated calcium and PTH levels based on a hyposensitive calcium sensing receptor (CaSR) in FHH 1 or its downstream regulatory pathway in FHH2 and FHH3. In children, adolescents and young adults with FHH the main challenge is to distinguish the condition from primary hyperparathyroidism and thereby to avoid unnecessary treatments including parathyroidectomy. However, inheritance of FHH may result in neonatal hyperparathyroidism (NHPT) or neonatal severe hyperparathyroidism (NSHPT), conditions with high morbidity, and in the latter even high mortality. This review focuses on the genetic and pathophysiological framework that leads to the severe neonatal form, gives recommendations for counselling and summarizes treatment options.
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Lemoine S, Figueres L, Bacchetta J, Frey S, Dubourg L. Calcium homeostasis pathologies in hyperparathyroidism: nephrologic and endocrinologic points of view. ANNALES D'ENDOCRINOLOGIE 2022; 83:237-243. [DOI: 10.1016/j.ando.2022.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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22
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Vargas-Poussou R. Pathophysiological aspects of the thick ascending limb and novel genetic defects: HELIX syndrome and transient antenatal Bartter syndrome. Pediatr Nephrol 2022; 37:239-252. [PMID: 33733301 DOI: 10.1007/s00467-021-05019-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 01/29/2021] [Accepted: 02/17/2021] [Indexed: 10/21/2022]
Abstract
The thick ascending limb plays a central role in human kidney physiology, participating in sodium reabsorption, urine concentrating mechanisms, calcium and magnesium homeostasis, bicarbonate and ammonium homeostasis, and uromodulin synthesis. This review aims to illustrate the importance of these roles from a pathophysiological point of view by describing the interactions of the key proteins of this segment and by discussing how recently identified and long-known hereditary diseases affect this segment. The descriptions of two recently described salt-losing tubulopathies, transient antenatal Bartter syndrome and HELIX syndrome, which are caused by mutations in MAGED2 and CLDN10 genes, respectively, highlight the role of new players in the modulation of sodium reabsorption the thick ascending limb.
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Affiliation(s)
- Rosa Vargas-Poussou
- Department of Molecular Genetics, Assistance Publique Hôpitaux de Paris, Hôpital Européen Georges-Pompidou, 20-40 rue Leblanc, 75015, Paris, France. .,Centre de Référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte (MARHEA), Paris, France. .,Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, Paris, France.
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23
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Chou KJ, Hsu CY, Huang CW, Chen HJ, Ou SH, Chen CL, Lee PT, Fang HC. A new missense mutation of calcium sensing receptor with isoleucine replaced by serine at codon 857 leading to type V Bartter syndrome. Exp Cell Res 2022; 414:113080. [DOI: 10.1016/j.yexcr.2022.113080] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 01/29/2022] [Accepted: 02/10/2022] [Indexed: 02/05/2023]
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Oton-Gonzalez L, Mazziotta C, Iaquinta MR, Mazzoni E, Nocini R, Trevisiol L, D’Agostino A, Tognon M, Rotondo JC, Martini F. Genetics and Epigenetics of Bone Remodeling and Metabolic Bone Diseases. Int J Mol Sci 2022; 23:ijms23031500. [PMID: 35163424 PMCID: PMC8836080 DOI: 10.3390/ijms23031500] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Revised: 01/24/2022] [Accepted: 01/26/2022] [Indexed: 02/06/2023] Open
Abstract
Bone metabolism consists of a balance between bone formation and bone resorption, which is mediated by osteoblast and osteoclast activity, respectively. In order to ensure bone plasticity, the bone remodeling process needs to function properly. Mesenchymal stem cells differentiate into the osteoblast lineage by activating different signaling pathways, including transforming growth factor β (TGF-β)/bone morphogenic protein (BMP) and the Wingless/Int-1 (Wnt)/β-catenin pathways. Recent data indicate that bone remodeling processes are also epigenetically regulated by DNA methylation, histone post-translational modifications, and non-coding RNA expressions, such as micro-RNAs, long non-coding RNAs, and circular RNAs. Mutations and dysfunctions in pathways regulating the osteoblast differentiation might influence the bone remodeling process, ultimately leading to a large variety of metabolic bone diseases. In this review, we aim to summarize and describe the genetics and epigenetics of the bone remodeling process. Moreover, the current findings behind the genetics of metabolic bone diseases are also reported.
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Affiliation(s)
- Lucia Oton-Gonzalez
- Department of Medical Sciences, University of Ferrara, 64/b, Fossato di Mortara Street, 44121 Ferrara, Italy; (L.O.-G.); (C.M.); (M.R.I.); (M.T.)
| | - Chiara Mazziotta
- Department of Medical Sciences, University of Ferrara, 64/b, Fossato di Mortara Street, 44121 Ferrara, Italy; (L.O.-G.); (C.M.); (M.R.I.); (M.T.)
- Center for Studies on Gender Medicine, Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy
| | - Maria Rosa Iaquinta
- Department of Medical Sciences, University of Ferrara, 64/b, Fossato di Mortara Street, 44121 Ferrara, Italy; (L.O.-G.); (C.M.); (M.R.I.); (M.T.)
- Center for Studies on Gender Medicine, Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy
| | - Elisa Mazzoni
- Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, 44121 Ferrara, Italy;
| | - Riccardo Nocini
- Unit of Otolaryngology, University of Verona, 37134 Verona, Italy;
| | - Lorenzo Trevisiol
- Unit of Maxillo-Facial Surgery and Dentistry, University of Verona, 37134 Verona, Italy; (L.T.); (A.D.)
| | - Antonio D’Agostino
- Unit of Maxillo-Facial Surgery and Dentistry, University of Verona, 37134 Verona, Italy; (L.T.); (A.D.)
| | - Mauro Tognon
- Department of Medical Sciences, University of Ferrara, 64/b, Fossato di Mortara Street, 44121 Ferrara, Italy; (L.O.-G.); (C.M.); (M.R.I.); (M.T.)
| | - John Charles Rotondo
- Department of Medical Sciences, University of Ferrara, 64/b, Fossato di Mortara Street, 44121 Ferrara, Italy; (L.O.-G.); (C.M.); (M.R.I.); (M.T.)
- Center for Studies on Gender Medicine, Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy
- Correspondence: (J.C.R.); (F.M.); Tel.: +39-0532-455536 (J.C.R.); +39-0532-455540 (F.M.)
| | - Fernanda Martini
- Department of Medical Sciences, University of Ferrara, 64/b, Fossato di Mortara Street, 44121 Ferrara, Italy; (L.O.-G.); (C.M.); (M.R.I.); (M.T.)
- Center for Studies on Gender Medicine, Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy
- Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, 44121 Ferrara, Italy
- Correspondence: (J.C.R.); (F.M.); Tel.: +39-0532-455536 (J.C.R.); +39-0532-455540 (F.M.)
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Abstract
Primary hyperparathyroidism (PHPT) is a commonly encountered clinical problem and occurs as part of an inherited disorder in ∼10% of patients. Several features may alert the clinician to the possibility of a hereditary PHPT disorder (eg, young age of disease onset) whilst establishing any relevant family history is essential to the clinical evaluation and will help inform the diagnosis. Genetic testing should be offered to patients at risk of a hereditary PHPT disorder, as this may improve management and allow the identification and investigation of other family members who may also be at risk of disease.
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Affiliation(s)
- Paul J Newey
- Division of Molecular and Clinical Medicine, Ninewells Hospital and Medical School, Jacqui Wood Cancer Centre, James Arrott Drive, Dundee, Scotland DD1 9SY, UK.
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26
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Gorkhali R, Tian L, Dong B, Bagchi P, Deng X, Pawar S, Duong D, Fang N, Seyfried N, Yang J. Extracellular calcium alters calcium-sensing receptor network integrating intracellular calcium-signaling and related key pathway. Sci Rep 2021; 11:20576. [PMID: 34663830 PMCID: PMC8523568 DOI: 10.1038/s41598-021-00067-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Accepted: 09/29/2021] [Indexed: 12/21/2022] Open
Abstract
G-protein-coupled receptors (GPCRs) are a target for over 34% of current drugs. The calcium-sensing receptor (CaSR), a family C GPCR, regulates systemic calcium (Ca2+) homeostasis that is critical for many physiological, calciotropical, and noncalciotropical outcomes in multiple organs. However, the mechanisms by which extracellular Ca2+ (Ca2+ex) and the CaSR mediate networks of intracellular Ca2+-signaling and players involved throughout the life cycle of CaSR are largely unknown. Here we report the first CaSR protein–protein interactome with 94 novel putative and 8 previously published interactors using proteomics. Ca2+ex promotes enrichment of 66% of the identified CaSR interactors, pertaining to Ca2+ dynamics, endocytosis, degradation, trafficking, and primarily to protein processing in the endoplasmic reticulum (ER). These enhanced ER-related processes are governed by Ca2+ex-activated CaSR which directly modulates ER-Ca2+ (Ca2+ER), as monitored by a novel ER targeted Ca2+-sensor. Moreover, we validated the Ca2+ex dependent colocalizations and interactions of CaSR with ER-protein processing chaperone, 78-kDa glucose regulated protein (GRP78), and with trafficking-related protein. Live cell imaging results indicated that CaSR and vesicle-associated membrane protein-associated A (VAPA) are inter-dependent during Ca2+ex induced enhancement of near-cell membrane expression. This study significantly extends the repertoire of the CaSR interactome and reveals likely novel players and pathways of CaSR participating in Ca2+ER dynamics, agonist mediated ER-protein processing and surface expression.
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Affiliation(s)
- Rakshya Gorkhali
- Department of Chemistry, Center of Diagnostics and Therapeutics, Advanced Translational Imaging Facility, Georgia State University, Atlanta, GA, 30303, USA
| | - Li Tian
- Department of Chemistry, Center of Diagnostics and Therapeutics, Advanced Translational Imaging Facility, Georgia State University, Atlanta, GA, 30303, USA
| | - Bin Dong
- Department of Chemistry, Center of Diagnostics and Therapeutics, Advanced Translational Imaging Facility, Georgia State University, Atlanta, GA, 30303, USA
| | - Pritha Bagchi
- Emory Integrated Proteomics Core, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Xiaonan Deng
- Department of Chemistry, Center of Diagnostics and Therapeutics, Advanced Translational Imaging Facility, Georgia State University, Atlanta, GA, 30303, USA
| | - Shrikant Pawar
- Department of Biology, Center of Diagnostics and Therapeutics, Advanced Translational Imaging Facility, Georgia State University, Atlanta, GA, 30303, USA
| | - Duc Duong
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Ning Fang
- Department of Chemistry, Center of Diagnostics and Therapeutics, Advanced Translational Imaging Facility, Georgia State University, Atlanta, GA, 30303, USA
| | - Nicholas Seyfried
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Jenny Yang
- Department of Chemistry, Center of Diagnostics and Therapeutics, Advanced Translational Imaging Facility, Georgia State University, Atlanta, GA, 30303, USA.
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27
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Arshad MF, McAllister J, Merchant A, Rab E, Cook J, Eastell R, Balasubramanian S. Urinary calcium indices in primary hyperparathyroidism (PHPT) and familial hypocalciuric hypercalcaemia (FHH): which test performs best? Postgrad Med J 2021; 97:577-582. [PMID: 32892159 DOI: 10.1136/postgradmedj-2020-137718] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 06/17/2020] [Accepted: 07/04/2020] [Indexed: 12/12/2022]
Abstract
AIM Primary hyperparathyroidism (PHPT) is much more common than familial hypocalciuric hypercalcaemia (FHH), but there is considerable overlap in biochemical features. Urine calcium indices help with the differential diagnosis, but their reliability in making this distinction is not clear. The aim of this study was to compare urinary calcium values in patients with PHPT and FHH. METHODS This was a case-control study of patients with PHPT who had successful surgery and genetically proven FHH between 2011 and 2016. Due to low FHH numbers, patients from neighbouring hospitals and outside study period (2017-2019) were allowed to improve power. Data on demographics and urinary calcium were obtained from electronic records and compared between the two groups. RESULTS During the study period, 250 patients underwent successful PHPT surgery, while in the FHH arm, 19 genetically proven cases were included. The median (IQR) 24-hour urine calcium excretion (UCE) in the PHPT group was 8.3 (5.6-11.2) mmol/24 hours compared with 3.2 (2.1-6.1) mmol/24 hour in the FHH group (p<0.001). Median (IQR) calcium to creatinine clearance ratio (CCCR) in the PHPT and FHH groups was 0.020 (0.013-0.026) and 0.01 (0.002-0.02), respectively (p=0.001). The sensitivity of urinary tests for PHPT was 96% for UCE (cut-off ≥2.5 mmol/24 hour) and 47% for CCCR (cut-off >0.02). The specificity of the urinary tests for FHH was 29.4% for UCE (cut-off <2.5 mmol/24 hour) and 93% for CCCR (cut-off <0.02). CONCLUSIONS 24-hour UCE is more sensitive in diagnosing PHPT; however, it is less specific in ruling out FHH as compared with CCCR, when the cut-offs suggested by the International guidelines from the fourth international workshop are used. A significant proportion of patients with PHPT would have also required genetic studies if the guidelines were followed.
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Affiliation(s)
- Muhammad Fahad Arshad
- Endocrinology, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK
- The University of Sheffield, Sheffield, UK
| | - James McAllister
- The University of Sheffield Medical School, Sheffield, Sheffield, UK
| | | | - Edmund Rab
- Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK
| | | | - Richard Eastell
- The University of Sheffield, Sheffield, UK
- Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK
| | - Sabapathy Balasubramanian
- The University of Sheffield, Sheffield, UK
- Endocrine Surgery, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK
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28
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Alam S, Goyal A, Tandon N. Clinical, Biochemical, and Genetic Profile of an Indian Kindred with Type 1 Familial Hypocalciuric Hypercalcemia. Indian J Endocrinol Metab 2021; 25:462-465. [PMID: 35300448 PMCID: PMC8923312 DOI: 10.4103/ijem.ijem_349_21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 09/27/2021] [Accepted: 10/04/2021] [Indexed: 12/03/2022] Open
Affiliation(s)
- Sarah Alam
- Department of Endocrinology and Metabolism, All India Institute of Medical Sciences, New Delhi, India
| | - Alpesh Goyal
- Department of Endocrinology and Metabolism, All India Institute of Medical Sciences, New Delhi, India
| | - Nikhil Tandon
- Department of Endocrinology and Metabolism, All India Institute of Medical Sciences, New Delhi, India
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29
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Zheng J, Liu G, Wu C, Jia G, Zhao H, Chen X, Wang J. Effect of calcium-sensing receptor on the migration and proliferation of porcine intestinal epithelial cells. Anim Biotechnol 2021; 34:365-374. [PMID: 34459707 DOI: 10.1080/10495398.2021.1968885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
The rapid healing of impaired intestinal surface plays a role in maintaining intestinal homeostasis. This study investigated the effect of calcium-sensing receptor (CaSR) on the migration and proliferation of intestinal porcine epithelial cells (IPEC-J2). Results showed that cell migration area and width were increased by R568 (CaSR activator) and decreased by NPS2143 (CaSR inhibitor). The protein level of GTP-rac1 and the phosphorylation of phospholipase C gamma 1 (PLCγ1) were increased by 2 µM R568. Furthermore, R568 + 120 µM NSC23766 (Rac1 inhibitor) and R568 + 1 µM U73122 (PLCγ1 inhibitor) decreased the protein level of GTP-rac1 and the phosphorylated PLCγ1, respectively, and both inhibited cell migration compared with R568. In addition, spermine increased the protein expression levels of CaSR and the levels of GTP-rac1 and the phosphorylated PLCγ1 and thereby promoted the migration of IPEC-J2 cells. Moreover, R568 improved the proliferation of the IPEC-J2 cells. Spermine increased cell proliferation, but NPS2143 incubated with spermine decreased cell proliferation compared with the spermine group. This study suggests that CaSR activation increased cell migration by activating Rac1 and PLCγ1 signaling and improved cell proliferation, and both effects were regulated by spermine by activating CaSR.
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Affiliation(s)
- Jie Zheng
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan, China.,Key Laboratory of Animal Disease-Resistance Nutrition, Ministry of Education, Chengdu, Sichuan, China.,Key laboratory of Animal Disease-resistant Nutrition and Feed, Ministry of Agriculture and Rural Affairs, Chengdu, Sichuan, China
| | - Guangmang Liu
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan, China.,Key Laboratory of Animal Disease-Resistance Nutrition, Ministry of Education, Chengdu, Sichuan, China.,Key laboratory of Animal Disease-resistant Nutrition and Feed, Ministry of Agriculture and Rural Affairs, Chengdu, Sichuan, China
| | - Caimei Wu
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan, China.,Key Laboratory of Animal Disease-Resistance Nutrition, Ministry of Education, Chengdu, Sichuan, China.,Key laboratory of Animal Disease-resistant Nutrition and Feed, Ministry of Agriculture and Rural Affairs, Chengdu, Sichuan, China
| | - Gang Jia
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan, China.,Key Laboratory of Animal Disease-Resistance Nutrition, Ministry of Education, Chengdu, Sichuan, China.,Key laboratory of Animal Disease-resistant Nutrition and Feed, Ministry of Agriculture and Rural Affairs, Chengdu, Sichuan, China
| | - Hua Zhao
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan, China.,Key Laboratory of Animal Disease-Resistance Nutrition, Ministry of Education, Chengdu, Sichuan, China.,Key laboratory of Animal Disease-resistant Nutrition and Feed, Ministry of Agriculture and Rural Affairs, Chengdu, Sichuan, China
| | - Xiaoling Chen
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan, China.,Key Laboratory of Animal Disease-Resistance Nutrition, Ministry of Education, Chengdu, Sichuan, China.,Key laboratory of Animal Disease-resistant Nutrition and Feed, Ministry of Agriculture and Rural Affairs, Chengdu, Sichuan, China
| | - Jing Wang
- Maize Research Institute, Sichuan Agricultural University, Chengdu, Sichuan, China
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30
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Li SR, McCoy KL, Levitt HE, Kelley ML, Carty SE, Yip L. Is routine 24-hour urine calcium measurement useful during the evaluation of primary hyperparathyroidism? Surgery 2021; 171:17-22. [PMID: 34325903 DOI: 10.1016/j.surg.2021.04.055] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 04/17/2021] [Accepted: 04/30/2021] [Indexed: 11/24/2022]
Abstract
BACKGROUND Primary hyperparathyroidism and familial hypocalciuric hypercalcemia have similar biochemical profiles, and calcium-to-creatinine-clearance ratio helps distinguish the two. Additionally, 24-hour urine calcium >400 mg/day indicates surgery and guidelines recommend obtaining 24-hour urine calcium preoperatively. Our aim was to assess how 24-hour urine calcium altered care in the evaluation of suspected primary hyperparathyroidism. METHODS Consecutive patients assessed for primary hyperparathyroidism from 2018 to 2020 were reviewed. Primary hyperparathyroidism was diagnosed by 2016 American Association of Endocrine Surgeons Parathyroidectomy Guidelines criteria. 24-hour urine calcium-directed change in care was defined as familial hypocalciuric hypercalcemia diagnosis, surgical deferment for additional testing, or 24-hour urine calcium >400 mg/day as the sole surgical indication. RESULTS Of 613 patients, 565 (92%) completed 24-hour urine calcium and 477 (84%) had concurrent biochemical testing to calculate calcium-to-creatinine-clearance ratio. 24-hour urine calcium was <100 mg/day in 9% (49/565) and calcium-to-creatinine-clearance ratio was <0.01 in 17% (82/477). No patient had confirmed familial hypocalciuric hypercalcemia, although 1 had a CASR variant of undetermined significance. When calcium-to-creatinine-clearance ratio was <0.01, familial hypocalciuric hypercalcemia was excluded by 24-hour urine calcium >100 mg/day (56%), prior normal calcium (16%), renal insufficiency (11%), absence of familial hypercalcemia (3%), normal repeat 24-hour urine calcium (10%), or interfering diuretic (1%). 24-hour urine calcium-directed change in care occurred in 25 (4%), including 4 (1%) who had genetic testing. Four-gland hyperplasia was more common with calcium-to-creatinine-clearance ratio <0.01 (17% vs calcium-to-creatinine-clearance ratio ≥ 0.01, 4%, P < .001), but surgical failure rates were equivalent (P = .24). CONCLUSION 24-hour urine calcium compliance was high, and results affected management in 4%, including productive identification of hypercalciuria as the sole surgical indication in 2 patients. When calcium-to-creatinine-clearance ratio <0.01, clinical assessment was sufficient to exclude familial hypocalciuric hypercalcemia and only 1% required genetic testing. 24-hour urine calcium should be ordered judiciously during primary hyperparathyroidism assessment.
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Affiliation(s)
- Shimena R Li
- Department of Surgery, University of Pittsburgh, PA
| | - Kelly L McCoy
- Department of Surgery, University of Pittsburgh, PA; Division of Endocrine Surgery, University of Pittsburgh, PA
| | - Helena E Levitt
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, PA
| | | | - Sally E Carty
- Department of Surgery, University of Pittsburgh, PA; Division of Endocrine Surgery, University of Pittsburgh, PA
| | - Linwah Yip
- Department of Surgery, University of Pittsburgh, PA; Division of Endocrine Surgery, University of Pittsburgh, PA.
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31
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Panova AV, Kulikova KS, Klementieva NV, Krylov ID, Snezhko IO, Tiulpakov AN, Kiselev SL. Generation of an induced pluripotent stem cell line HPCASRi002-A from a patient with neonatal severe primary hyperparathyroidism caused by a compound heterozygous mutation in the CASR gene. Stem Cell Res 2021; 54:102414. [PMID: 34111698 DOI: 10.1016/j.scr.2021.102414] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/06/2021] [Accepted: 05/30/2021] [Indexed: 02/07/2023] Open
Abstract
Neonatal severe primary hyperparathyroidism (NSHPT) is a rare autosomal recessive disorder of calcium homeostasis that manifests shortly after birth with hypercalcemia and bone disease. NSHPT, in most cases, is attributed to mutations in the calcium-sensing receptor (CASR) gene. We reprogrammed dermal fibroblasts derived from a patient with NSHPT carrying a compound heterozygous mutation in the CASR gene into induced pluripotent stem cells (iPSCs). The established iPSCs expressed pluripotency markers, maintained normal karyotype and differentiated into all three germ layers. This line is a valuable resource for modeling of hyperparathyroidism related to CASR mutations.
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Affiliation(s)
- Alexandra V Panova
- Endocrinology Research Centre, Moscow, Russia; Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, Russia.
| | | | | | | | | | - Anatoly N Tiulpakov
- Endocrinology Research Centre, Moscow, Russia; Research Centre for Medical Genetics, Moscow, Russia
| | - Sergey L Kiselev
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, Russia
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32
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Wen T, Wang Z, Chen X, Ren Y, Lu X, Xing Y, Lu J, Chang S, Zhang X, Shen Y, Yang X. Structural basis for activation and allosteric modulation of full-length calcium-sensing receptor. SCIENCE ADVANCES 2021; 7:7/23/eabg1483. [PMID: 34088669 PMCID: PMC8177707 DOI: 10.1126/sciadv.abg1483] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 04/19/2021] [Indexed: 06/12/2023]
Abstract
Calcium-sensing receptor (CaSR) is a class C G protein-coupled receptor (GPCR) that plays an important role in calcium homeostasis and parathyroid hormone secretion. Here, we present multiple cryo-electron microscopy structures of full-length CaSR in distinct ligand-bound states. Ligands (Ca2+ and l-tryptophan) bind to the extracellular domain of CaSR and induce large-scale conformational changes, leading to the closure of two heptahelical transmembrane domains (7TMDs) for activation. The positive modulator (evocalcet) and the negative allosteric modulator (NPS-2143) occupy the similar binding pocket in 7TMD. The binding of NPS-2143 causes a considerable rearrangement of two 7TMDs, forming an inactivated TM6/TM6 interface. Moreover, a total of 305 disease-causing missense mutations of CaSR have been mapped to the structure in the active state, creating hotspot maps of five clinical endocrine disorders. Our results provide a structural framework for understanding the activation, allosteric modulation mechanism, and disease therapy for class C GPCRs.
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Affiliation(s)
- Tianlei Wen
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, Tianjin 300350, China
| | - Ziyu Wang
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, Tianjin 300350, China
| | - Xiaozhe Chen
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, Tianjin 300350, China
| | - Yue Ren
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, Tianjin 300350, China
| | - Xuhang Lu
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, Tianjin 300350, China
| | - Yangfei Xing
- State Key Laboratory of Medical Genomics, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200025, China
| | - Jing Lu
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, Tianjin 300350, China
| | - Shenghai Chang
- Department of Biophysics and Department of Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Center of Cryo-Electron Microscopy, Zhejiang University School of Medicine, Hangzhou, China
| | - Xing Zhang
- Department of Biophysics and Department of Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Center of Cryo-Electron Microscopy, Zhejiang University School of Medicine, Hangzhou, China
| | - Yuequan Shen
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, Tianjin 300350, China.
- Synergetic Innovation Center of Chemical Science and Engineering, Tianjin 300071, China
| | - Xue Yang
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, Tianjin 300350, China.
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Papadopoulou A, Bountouvi E, Karachaliou FE. The Molecular Basis of Calcium and Phosphorus Inherited Metabolic Disorders. Genes (Basel) 2021; 12:genes12050734. [PMID: 34068220 PMCID: PMC8153134 DOI: 10.3390/genes12050734] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 04/30/2021] [Accepted: 05/05/2021] [Indexed: 02/07/2023] Open
Abstract
Calcium (Ca) and Phosphorus (P) hold a leading part in many skeletal and extra-skeletal biological processes. Their tight normal range in serum mirrors their critical role in human well-being. The signalling “voyage” starts at Calcium Sensing Receptor (CaSR) localized on the surface of the parathyroid glands, which captures the “oscillations” of extracellular ionized Ca and transfers the signal downstream. Parathyroid hormone (PTH), Vitamin D, Fibroblast Growth Factor (FGF23) and other receptors or ion-transporters, work synergistically and establish a highly regulated signalling circuit between the bone, kidneys, and intestine to ensure the maintenance of Ca and P homeostasis. Any deviation from this well-orchestrated scheme may result in mild or severe pathologies expressed by biochemical and/or clinical features. Inherited disorders of Ca and P metabolism are rare. However, delayed diagnosis or misdiagnosis may cost patient’s quality of life or even life expectancy. Unravelling the thread of the molecular pathways involving Ca and P signaling, we can better understand the link between genetic alterations and biochemical and/or clinical phenotypes and help in diagnosis and early therapeutic intervention.
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34
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Brouns I, Verckist L, Pintelon I, Timmermans JP, Adriaensen D. Pulmonary Sensory Receptors. ADVANCES IN ANATOMY EMBRYOLOGY AND CELL BIOLOGY 2021; 233:1-65. [PMID: 33950466 DOI: 10.1007/978-3-030-65817-5_1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Inge Brouns
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Antwerpen (Wilrijk), Belgium.
| | - Line Verckist
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Antwerpen (Wilrijk), Belgium
| | - Isabel Pintelon
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Antwerpen (Wilrijk), Belgium
| | - Jean-Pierre Timmermans
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Antwerpen (Wilrijk), Belgium
| | - Dirk Adriaensen
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Antwerpen (Wilrijk), Belgium
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35
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A novel case of neonatal severe hyperparathyroidism successfully treated with a type II calcimimetic drug. Bone Rep 2021; 14:100761. [PMID: 33748353 PMCID: PMC7972953 DOI: 10.1016/j.bonr.2021.100761] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 02/21/2021] [Accepted: 03/01/2021] [Indexed: 11/24/2022] Open
Abstract
We report a boy with hypercalcemia due to neonatal severe hyperparathyroidism (NSHPT) caused by a compound heterozygous mutation in the calcium sensing receptor (CaSR) managed successfully on a type II calcimimetic drug. The hypercalcemia was temporarily treated by hyperhydration, bisphosphonate and calcium depleted milk. At 29 days of age cinacalcet was introduced. The starting dose was 0.5 mg/kg/day and was subsequently titrated to the point of efficacy (5.2 mg/kg/day) when a persuasive reduction in parathyroid hormone and calcium concentrations was observed. We propose a trial of type II calcimimetics in newborns with NSHPT irrespective of the genetic mutation and advocate that residual functionality of the CaSR predict the drug efficacy.
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Diao J, DeBono A, Josephs TM, Bourke JE, Capuano B, Gregory KJ, Leach K. Therapeutic Opportunities of Targeting Allosteric Binding Sites on the Calcium-Sensing Receptor. ACS Pharmacol Transl Sci 2021; 4:666-679. [PMID: 33860192 DOI: 10.1021/acsptsci.1c00046] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Indexed: 01/24/2023]
Abstract
The CaSR is a class C G protein-coupled receptor (GPCR) that acts as a multimodal chemosensor to maintain diverse homeostatic functions. The CaSR is a clinical therapeutic target in hyperparathyroidism and has emerged as a putative target in several other diseases. These include hyper- and hypocalcaemia caused either by mutations in the CASR gene or in genes that regulate CaSR signaling and expression, and more recently in asthma. The development of CaSR-targeting drugs is complicated by the fact that the CaSR possesses many different binding sites for endogenous and exogenous agonists and allosteric modulators. Binding sites for endogenous and exogenous ligands are located throughout the large CaSR protein and are interconnected in ways that we do not yet fully understand. This review summarizes our current understanding of CaSR physiology, signaling, and structure and how the many different binding sites of the CaSR may be targeted to treat disease.
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Affiliation(s)
- Jiayin Diao
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Aaron DeBono
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia.,Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Tracy M Josephs
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Jane E Bourke
- Department of Pharmacology, Biomedicine Discovery Institute, Monash University, 9 Ancora Imparo Way, Clayton, Victoria 3800, Australia
| | - Ben Capuano
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Karen J Gregory
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia.,Department of Pharmacology, Biomedicine Discovery Institute, Monash University, 9 Ancora Imparo Way, Clayton, Victoria 3800, Australia
| | - Katie Leach
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia.,Department of Pharmacology, Biomedicine Discovery Institute, Monash University, 9 Ancora Imparo Way, Clayton, Victoria 3800, Australia
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Appelman-Dijkstra NM, Ertl DA, Zillikens MC, Rjenmark L, Winter EM. Hypercalcemia during pregnancy: management and outcomes for mother and child. Endocrine 2021; 71:604-610. [PMID: 33544354 PMCID: PMC8016748 DOI: 10.1007/s12020-021-02615-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 01/08/2021] [Indexed: 11/28/2022]
Abstract
Diagnosing and treating hypercalcemia during pregnancy can be challenging due to both the physiological changes in calcium homeostasis and the underlying cause for the hypercalcemia. During pregnancy and lactation there is increased mobilization of calcium in the mother to meet the fetus' calcium requirements. Here we discuss the diagnostic challenges, management, and patient perspective of hypercalcemia during pregnancy in two particular cases and in other rare conditions causing hypercalcemia.
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Affiliation(s)
- Natasha M Appelman-Dijkstra
- Department of Internal Medicine, Division of Endocrinology, Center for Bone Quality, Leiden University Medical Center, Leiden, the Netherlands.
| | - Diana- Alexandra Ertl
- Department for Pediatric Pulmonology, Allergology and Endocrinology, Comprehensive Center for Pediatrics, Medical University of Vienna, Vienna, Austria
- Center of Expertise for Rare Disorders of Bone, Growth and Mineralization, Vienna Bone and Growth Center, Vienna, Austria
| | - M C Zillikens
- Department of Internal Medicine, Erasmus MC Bone Center, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Lars Rjenmark
- Department of Clinical Medicine; Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Elizabeth M Winter
- Department of Internal Medicine, Division of Endocrinology, Center for Bone Quality, Leiden University Medical Center, Leiden, the Netherlands
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Calcium-Sensing Receptor (CaSR), Its Impact on Inflammation and the Consequences on Cardiovascular Health. Int J Mol Sci 2021; 22:ijms22052478. [PMID: 33804544 PMCID: PMC7957814 DOI: 10.3390/ijms22052478] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 02/11/2021] [Accepted: 02/25/2021] [Indexed: 12/15/2022] Open
Abstract
The calcium Sensing Receptor (CaSR) is a cell surface receptor belonging to the family of G-protein coupled receptors. CaSR is mainly expressed by parathyroid glands, kidneys, bone, skin, adipose tissue, the gut, the nervous system, and the cardiovascular system. The receptor, as its name implies is involved in sensing calcium fluctuations in the extracellular matrix of cells, thereby having a major impact on the mineral homeostasis in humans. Besides calcium ions, the receptor is also activated by other di- and tri-valent cations, polypeptides, polyamines, antibiotics, calcilytics and calcimimetics, which upon binding induce intracellular signaling pathways. Recent studies have demonstrated that CaSR influences a wide variety of cells and processes that are involved in inflammation, the cardiovascular system, such as vascular calcification, atherosclerosis, myocardial infarction, hypertension, and obesity. Therefore, in this review, the current understanding of the role that CaSR plays in inflammation and its consequences on the cardiovascular system will be highlighted.
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Tőke J, Czirják G, Enyedi P, Tóth M. Rare diseases caused by abnormal calcium sensing and signalling. Endocrine 2021; 71:611-617. [PMID: 33528764 PMCID: PMC8016752 DOI: 10.1007/s12020-021-02620-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Accepted: 01/08/2021] [Indexed: 12/20/2022]
Abstract
The calcium-sensing receptor (CaSR) provides the major mechanism for the detection of extracellular calcium concentration in several cell types, via the induction of G-protein-coupled signalling. Accordingly, CaSR plays a pivotal role in calcium homeostasis, and the CaSR gene defects are related to diseases characterized by serum calcium level changes. Activating mutations of the CaSR gene cause enhanced sensitivity to extracellular calcium concentration resulting in autosomal dominant hypocalcemia or Bartter-syndrome type V. Inactivating CaSR gene mutations lead to resistance to extracellular calcium. In these cases, familial hypocalciuric hypercalcaemia (FHH1) or neonatal severe hyperparathyroidism (NSHPT) can develop. FHH2 and FHH3 are associated with mutations of genes of partner proteins of calcium signal transduction. The common polymorphisms of the CaSR gene have been reported not to affect the calcium homeostasis itself; however, they may be associated with the increased risk of malignancies.
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Affiliation(s)
- Judit Tőke
- Department of Internal Medicine and Oncology, Semmelweis University, Budapest, Hungary
| | - Gábor Czirják
- Department of Physiology, Semmelweis University, Budapest, Hungary
| | - Péter Enyedi
- Department of Physiology, Semmelweis University, Budapest, Hungary
| | - Miklós Tóth
- Department of Internal Medicine and Oncology, Semmelweis University, Budapest, Hungary.
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Tsuji T, Hiroyuki A, Uraki S, Doi A, Morita S, Iwakura H, Nishi M, Furuta H, Akamizu T. Autosomal Dominant Hypocalcemia With Atypical Urine Findings Accompanied by Novel CaSR Gene Mutation and VitD Deficiency. J Endocr Soc 2021; 5:bvaa190. [PMID: 33506158 PMCID: PMC7814383 DOI: 10.1210/jendso/bvaa190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Indexed: 11/19/2022] Open
Abstract
Introduction Autosomal dominant hypocalcemia (ADH) is caused by gain-of-function mutations of the calcium sensing receptor (CaSR). It is characterized by hypercalciuria in spite of hypocalcemia. Vitamin D deficiency increases calcium reabsorption in the distal tubules of the kidneys, resulting in hypocalciuria. Materials and methods A 38-year-old female proband had hypocalcemia, hypocalciuria, and vitamin D deficiency. Her father and brother also had hypocalcemia, but her mother was normocalcemic. We analyzed the CaSR gene abnormality in this family. Polymerase chain reaction (PCR) and sequence analysis were performed to explore the CaSR gene mutation. Mutagenesis, transfection, and functional analysis were performed on the discovered genetic abnormalities. Result PCR and sequence analysis revealed that the proband, her father, and brother had a novel heterozygous mutation of the CaSR genes that causes threonine to asparagine substitution at codon 186 (T186N). Using HEK293 cells transfected with wild-type or T186N CaSR complementary DNA, we assessed the intracellular Ca2+ concentration in response to changes in the extracellular Ca2+ concentration. The cells transfected mutant CaSR gene had higher activity than that of wild-type. Therefore, we determined our patient had ADH with a novel mutation of the CaSR gene and hypocalciuria resulting from a vitamin D deficiency. We administered vitamin D to the proband, which caused elevation of her urinary calcium level, a typical finding of ADH. Conclusion Vitamin D deficiency was suggested to potentially mask hypercalciuria in ADH. Hypocalcemia with vitamin D deficiency should be diagnosed with care.
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Affiliation(s)
- Tomoya Tsuji
- First Department of Medicine, Wakayama Medical University, Wakayama, Wakayama Prefecture, Japan
| | - Ariyasu Hiroyuki
- First Department of Medicine, Wakayama Medical University, Wakayama, Wakayama Prefecture, Japan
| | - Shinsuke Uraki
- First Department of Medicine, Wakayama Medical University, Wakayama, Wakayama Prefecture, Japan
| | - Asako Doi
- First Department of Medicine, Wakayama Medical University, Wakayama, Wakayama Prefecture, Japan
| | - Shuhei Morita
- First Department of Medicine, Wakayama Medical University, Wakayama, Wakayama Prefecture, Japan
| | - Hiroshi Iwakura
- First Department of Medicine, Wakayama Medical University, Wakayama, Wakayama Prefecture, Japan
| | - Masahiro Nishi
- First Department of Medicine, Wakayama Medical University, Wakayama, Wakayama Prefecture, Japan
| | - Hiroto Furuta
- First Department of Medicine, Wakayama Medical University, Wakayama, Wakayama Prefecture, Japan
| | - Takashi Akamizu
- Internal Medicine, Kuma Hospital, Chuo-ku, Kobe, Hyogo Prefecture, Japan
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Mukhtar NN, Abouzied MEDM, Alqahtani MH, Hammami MM. Misleading localization by 18F-fluorocholine PET/CT in familial hypocalciuric hypercalcemia type-3: a case report. BMC Endocr Disord 2021; 21:20. [PMID: 33499837 PMCID: PMC7836468 DOI: 10.1186/s12902-021-00683-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 01/19/2021] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND Familial hypocalciuric hypercalcemia (FHH) is a heterogeneous autosomal-dominant disorder of calcium hemostasis that may be difficult to distinguish clinically from mild primary hyperparathyroidism. Loss-of-function mutations mainly involving Arg15 residue of the adaptor-related protein complex 2, sigma subunit 1 (AP2S1) cause a rarer, more recently recognized form of FHH, FFH type-3. Recently, 18F-fluorocholine positron emission tomography/computed tomography (FCH-PET/CT) showed superior sensitivity to conventional imaging in localizing parathyroid adenomas. We report a new FFH type-3 patient who underwent unnecessary parathyroidectomy in association with misleading FCH-PET/CT imaging. CASE PRESENTATION A 29-year old woman was initially evaluated for parathyroid hormone (PTH)-dependent hypercalcemia in 2013. Medical history was positive only for chronic constipation and malaise with no personal or family history of hypercalcemia, kidney stones, or neck surgery. Over seven years, serum calcium level was 2.51-2.89 mmol/L with concomitant PTH level of 58.7-94.8 mmol/L. Serum phosphate levels were in the low/low normal range. Serum creatinine and magnesium levels were normal. 25-hydroxy vitamin D level was 13 nmol/L. 24-hour urine calcium level was 1.92 mmol/day but increased to 6.99 mmol/day after treatment with cholecalciferol 1000 IU daily. Bone mineral density and renal ultrasound were normal. Parathyroid ultrasound showed two hypoechoic nodules inferior to the left and right thyroid lobes; however, 99mtechnitium-sestamibi scans (2013, 2016, 2018) were negative. FCH-PET/CT (2019) showed focal uptake co-localizing with the nodule inferior to the left thyroid lobe. The patient underwent left inferior parathyroidectomy and pathology was consistent with parathyroid hyperplasia. However, postoperatively, serum calcium and PTH levels remained elevated and FCH-PET/CT and ultrasound showed persistence of the uptake/nodule. Whole exome sequencing showed Arg15Cys mutation in the AP2S1 gene characteristic of FHH type-3. CONCLUSIONS In this new case of FHH type-3, FCH-PET/CT failed to localize to the hyperplastic parathyroid glands and localized instead to apparently a lymph node. This, together with increased urinary calcium after vitamin D supplementation, led to unnecessary parathyroidectomy. Given the increasingly lower cost of genetic testing and the cost of follow up and unnecessary surgery, it may prudent to include genetic testing for FHH early on in patients with mild PTH-dependent hypercalcemia.
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Affiliation(s)
- Noha N Mukhtar
- Department of Medicine , King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | | | - Mohammed H Alqahtani
- Department of Cyclotron and Radiopharmaceuticals, Alfaisal University, Riyadh, Saudi Arabia
| | - Muhammad M Hammami
- Department of Medicine , King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
- Department of Clinical Studies and Empirical Ethics, King Faisal Specialist Hospital and Research Centre, P O Box # 3354 (MBC 03), 11211 Riyadh, Saudi Arabia
- College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
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Höppner J, Lais S, Roll C, Wegener-Panzer A, Wieczorek D, Högler W, Grasemann C. Case Report: Severe Neonatal Course in Paternally Derived Familial Hypocalciuric Hypercalcemia. Front Endocrinol (Lausanne) 2021; 12:700612. [PMID: 34659108 PMCID: PMC8518617 DOI: 10.3389/fendo.2021.700612] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 09/06/2021] [Indexed: 12/23/2022] Open
Abstract
Familial hypocalciuric hypercalcemia (FHH, [OMIM #145980]) is recognized as a benign endocrine condition affecting PTH and calcium levels due to heterozygous inactivating mutations in the calcium sensing receptor (CaSR). The condition is often un- or misdiagnosed but may have a prevalence as high as 74 in 100.000. Here, the neonatal courses of two brothers with paternally inherited FHH (CaSR c.554G>A; p.(Arg185Gln)) are described. The older brother was born preterm at 25 weeks gestation with hypercalcemia and hyperparathyroidism. The younger brother, born full-term, had severe hyperparathyroidism, muscular hypotonia, thrombocytopenia, failure to thrive and multiple metaphyseal fractures. Treatment with cinacalcet was initiated, which resulted in subsequent reduction of PTH levels and prompt clinical improvement. While it is known that homozygous mutations in CaSR may lead to life-threatening forms of neonatal severe hyperparathyroidism (NSHPT), few reports have described a severe clinical course in neonates with FHH due to heterozygous mutations. However, based on the pathophysiological framework, in de novo or paternally transmitted FHH the differing calcium needs of mother and fetus can be expected to induce fetal hyperparathyroidism and may result in severe perinatal complications as described in this report. In summary, FHH is a mostly benign condition, but transient neonatal hyperparathyroidism may occur in affected neonates if the mutation is paternally inherited. If severe, the condition can be treated successfully with cinacalcet. Patients with FHH should be informed about the risk of neonatal disease manifestation in order to monitor pregnancies and neonates.
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MESH Headings
- Calcium/metabolism
- Heat-Shock Proteins/genetics
- Humans
- Hypercalcemia/complications
- Hypercalcemia/congenital
- Hyperparathyroidism, Primary/etiology
- Hyperparathyroidism, Primary/metabolism
- Hyperparathyroidism, Primary/pathology
- Infant, Newborn
- Infant, Newborn, Diseases/etiology
- Infant, Newborn, Diseases/metabolism
- Infant, Newborn, Diseases/pathology
- Male
- Mutation
- Paternal Inheritance
- Prognosis
- Scavenger Receptors, Class A/genetics
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Affiliation(s)
- Jakob Höppner
- Department of Pediatrics, St Josef-Hospital Bochum, Ruhr-University Bochum, Bochum, Germany
| | - Sabrina Lais
- Department of Neonatology, Pediatric Intensive Care and Sleep Medicine, Vestische Kinder- und Jugendklinik Datteln, University Witten/Herdecke, Datteln, Germany
| | - Claudia Roll
- Department of Neonatology, Pediatric Intensive Care and Sleep Medicine, Vestische Kinder- und Jugendklinik Datteln, University Witten/Herdecke, Datteln, Germany
| | - Andreas Wegener-Panzer
- Department of Radiology, Vestische Kinder- und Jugendklinik Datteln, University Witten/Herdecke, Datteln, Germany
| | - Dagmar Wieczorek
- Institute of Human Genetics, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Wolfgang Högler
- Department of Paediatrics and Adolescent Medicine, Johannes Kepler University Linz, Linz, Austria
| | - Corinna Grasemann
- Department of Pediatrics, St Josef-Hospital Bochum, Ruhr-University Bochum, Bochum, Germany
- *Correspondence: Corinna Grasemann,
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Functional Exploration of the Pulmonary NEB ME. ADVANCES IN ANATOMY, EMBRYOLOGY, AND CELL BIOLOGY 2021; 233:31-67. [PMID: 33950469 DOI: 10.1007/978-3-030-65817-5_4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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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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Li X, Chen S, Hu Z, Chen D, Wang J, Li Z, Li Z, Cui H, Dai G, Liu L, Wang H, Zhang K, Zheng Z, Zhan Z, Liu H. Aberrant upregulation of CaSR promotes pathological new bone formation in ankylosing spondylitis. EMBO Mol Med 2020; 12:e12109. [PMID: 33259138 PMCID: PMC7721361 DOI: 10.15252/emmm.202012109] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 10/13/2020] [Accepted: 10/14/2020] [Indexed: 12/28/2022] Open
Abstract
Pathological new bone formation is a typical pathological feature in ankylosing spondylitis (AS), and the underlying molecular mechanism remains elusive. Previous studies have shown that the calcium‐sensing receptor (CaSR) is critical for osteogenic differentiation while also being highly involved in many inflammatory diseases. However, whether it plays a role in pathological new bone formation of AS has not been reported. Here, we report the first piece of evidence that expression of CaSR is aberrantly upregulated in entheseal tissues collected from AS patients and animal models with different hypothetical types of pathogenesis. Systemic inhibition of CaSR reduced the incidence of pathological new bone formation and the severity of the ankylosing phenotype in animal models. Activation of PLCγ signalling by CaSR promoted bone formation both in vitro and in vivo. In addition, various inflammatory cytokines induced upregulation of CaSR through NF‐κB/p65 and JAK/Stat3 pathways in osteoblasts. These novel findings suggest that inflammation‐induced aberrant upregulation of CaSR and activation of CaSR‐PLCγ signalling in osteoblasts act as mediators of inflammation, affecting pathological new bone formation in AS.
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Affiliation(s)
- Xiang Li
- Department of Spine Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.,Guangdong Province Key Laboratory of Orthopaedics and Traumatology, Guangzhou, China
| | - Siwen Chen
- Department of Spine Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.,Guangdong Province Key Laboratory of Orthopaedics and Traumatology, Guangzhou, China
| | - Zaiying Hu
- Department of Rheumatology and Immunology, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Dongying Chen
- Department of Rheumatology and Immunology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Jianru Wang
- Department of Spine Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.,Guangdong Province Key Laboratory of Orthopaedics and Traumatology, Guangzhou, China
| | - Zemin Li
- Department of Spine Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.,Guangdong Province Key Laboratory of Orthopaedics and Traumatology, Guangzhou, China
| | - Zihao Li
- Department of Spine Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.,Guangdong Province Key Laboratory of Orthopaedics and Traumatology, Guangzhou, China
| | - Haowen Cui
- Department of Spine Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.,Guangdong Province Key Laboratory of Orthopaedics and Traumatology, Guangzhou, China
| | - Guo Dai
- Department of Spine Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.,Guangdong Province Key Laboratory of Orthopaedics and Traumatology, Guangzhou, China
| | - Lei Liu
- Department of Spine Surgery, The Fifth Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Haitao Wang
- Department of Spine Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.,Guangdong Province Key Laboratory of Orthopaedics and Traumatology, Guangzhou, China
| | - Kuibo Zhang
- Department of Spine Surgery, The Fifth Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Zhaomin Zheng
- Department of Spine Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.,Guangdong Province Key Laboratory of Orthopaedics and Traumatology, Guangzhou, China
| | - Zhongping Zhan
- Department of Rheumatology and Immunology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Hui Liu
- Department of Spine Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.,Guangdong Province Key Laboratory of Orthopaedics and Traumatology, Guangzhou, China
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Ahmad R, Dalziel JE. G Protein-Coupled Receptors in Taste Physiology and Pharmacology. Front Pharmacol 2020; 11:587664. [PMID: 33390961 PMCID: PMC7774309 DOI: 10.3389/fphar.2020.587664] [Citation(s) in RCA: 87] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 10/09/2020] [Indexed: 12/14/2022] Open
Abstract
Heterotrimeric G protein-coupled receptors (GPCRs) comprise the largest receptor family in mammals and are responsible for the regulation of most physiological functions. Besides mediating the sensory modalities of olfaction and vision, GPCRs also transduce signals for three basic taste qualities of sweet, umami (savory taste), and bitter, as well as the flavor sensation kokumi. Taste GPCRs reside in specialised taste receptor cells (TRCs) within taste buds. Type I taste GPCRs (TAS1R) form heterodimeric complexes that function as sweet (TAS1R2/TAS1R3) or umami (TAS1R1/TAS1R3) taste receptors, whereas Type II are monomeric bitter taste receptors or kokumi/calcium-sensing receptors. Sweet, umami and kokumi receptors share structural similarities in containing multiple agonist binding sites with pronounced selectivity while most bitter receptors contain a single binding site that is broadly tuned to a diverse array of bitter ligands in a non-selective manner. Tastant binding to the receptor activates downstream secondary messenger pathways leading to depolarization and increased intracellular calcium in TRCs, that in turn innervate the gustatory cortex in the brain. Despite recent advances in our understanding of the relationship between agonist binding and the conformational changes required for receptor activation, several major challenges and questions remain in taste GPCR biology that are discussed in the present review. In recent years, intensive integrative approaches combining heterologous expression, mutagenesis and homology modeling have together provided insight regarding agonist binding site locations and molecular mechanisms of orthosteric and allosteric modulation. In addition, studies based on transgenic mice, utilizing either global or conditional knock out strategies have provided insights to taste receptor signal transduction mechanisms and their roles in physiology. However, the need for more functional studies in a physiological context is apparent and would be enhanced by a crystallized structure of taste receptors for a more complete picture of their pharmacological mechanisms.
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Affiliation(s)
- Raise Ahmad
- Food Nutrition and Health Team, Food and Bio-based Products Group, AgResearch, Palmerston North, New Zealand
| | - Julie E Dalziel
- Food Nutrition and Health Team, Food and Bio-based Products Group, AgResearch, Palmerston North, New Zealand
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47
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Kerut S, Kovvuru KR, Yanes-Cardozo L, Garla VV. Familial hypocalciuric hypercalcaemia type 3: AP2S1 missense mutation. BMJ Case Rep 2020; 13:13/11/e236631. [PMID: 33168530 DOI: 10.1136/bcr-2020-236631] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
A 45-year-old man was referred to endocrine for the evaluation of hypercalcaemia. The calcium was elevated, vitamin D was low with a normal parathyroid hormone. Dual-energy X-ray absorptiometry scan revealed osteoporosis at the lumbar spine and femoral neck. A 24-hour urine collection revealed low urinary calcium, which was believed to be secondary to vitamin D deficiency. A diagnosis of primary hyperparathyroidism was made. The patient underwent a four-gland parathyroid exploration surgery in which three of his parathyroid glands were removed. The pathology was consistent with benign parathyroid tissue. Post surgery, the patient had persistently elevated calcium levels. He was then started on bisphosphonate and cinacalcet for osteoporosis and hypercalcaemia, respectively. Genetic analysis of familial hypocalciuric hypercalcaemia (FHH) showed a p.arg15cys mutation in the AP2S1 gene, confirming the diagnosis of FHH type 3.
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Affiliation(s)
- Sarah Kerut
- Internal Medicine, University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Karthik Reddy Kovvuru
- Mississippi Center for Clincal and Translational Center, University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Licy Yanes-Cardozo
- Mississippi Center for Clincal and Translational Center, University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Vishnu Vardhan Garla
- Mississippi Center for Clincal and Translational Center, University of Mississippi Medical Center, Jackson, Mississippi, USA
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Krupinova JA, Almaskhanova AA, Eremkina AK, Bibik EE, Vasilyev EV, Mokrysheva NG. [A series of clinical cases of familial hypocalciuric hypercalcemia syndrome]. ACTA ACUST UNITED AC 2020; 66:61-69. [PMID: 33369373 DOI: 10.14341/probl12537] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 09/12/2020] [Accepted: 09/12/2020] [Indexed: 12/19/2022]
Abstract
Familial hypocalciuric hypercalcemia (FHH) - rare disease with predominantly autosomal dominant inheritance. FHH typically develops due to a heterozygous inactivating mutation in the calcium-sensitive receptor gene (CASR), less commonly due to heterozygous mutations in GNA11 and AP2S1. CASR mutations lead to an increase in the threshold for calcium sensitivity, which requires a higher concentration in serum to reduce the release of PTH. These changes are accompanied by an increase of calcium and magnesium reabsorption in the proximal tubules, which leads to hypercalcemia and hypocalciuria. Basically, FHH may be asymptomatic or accompanied by mild hypercalcemia. FHH doesn't require surgical treatment, unlike primary hyperparathyroidism (PHPT), therefore, differential diagnosis of these two conditions is extremely important. In addition, immediate relatives of a proband with FHH also require the exclusion of disease inheritance. We analyzed a series of clinical cases with a genetically confirmed diagnosis of FHH. Our clinical cases indicate a variety of clinical manifestations and the difficulties of differential diagnosis with PHPT.
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Zajíčková K, Dvořáková M, Moravcová J, Včelák J, Goltzman D. Familial hypocalciuric hypercalcemia in an index male: grey zones of the differential diagnosis from primary hyperparathyroidism in a 13-year clinical follow up. Physiol Res 2020; 69:S321-S328. [PMID: 33094630 DOI: 10.33549/physiolres.934522] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Familial hypocalciuric hypercalcemia (FHH) type 1, caused by a heterozygous inactivating mutation of the gene encoding the calcium-sensing receptor (CaSR), is characterized by mild to moderate hypercalcemia, hypocalciuria and inappropriately normal or elevated parathyroid hormone (PTH). FHH must be differentiated from primary hyperparathyroidism (PHPT) because parathyroidectomy is ineffective in the former. Herein, we report a 39-year-old male patient with a 13-year history of asymptomatic PTH-dependent hypercalcemia (mean calcium of 2.88 mmol/l; reference range 2.15-2.55 mmol/l) and calcium-to-creatinine clearance ratio (Ca/Cr) ranging from 0.007 to 0.0198, which is consistent with either FHH or PHPT. Although a family history of hypercalcemia was negative, and PET-CT with fluorocholine was suggestive of a parathyroid adenoma, genetic analysis of the CaSR gene identified a heterozygous inactivating mutation NM_000388.4:c.1670G>A p. (Gly557Glu) in exon 6 and a polymorphism NM_000388.4:c.1192G>A p. (Asp398Asn) in exon 4. The G557E mutation has been previously reported in a Japanese family in which all family members with the mutation had Ca/Cr below 0.01 consistent with FHH. The biochemical profile of FHH and PHPT may overlap. Our FHH patient with a G557E CaSR mutation illustrates that the differential diagnosis can be difficult in an index case with no family history, (false) positive parathyroid imaging and higher calciuria than expected for FHH. Calcium intake, vitamin D status and bone resorption might have contributed to the Ca/Cr variations over a 13-year clinical follow up. This case thus emphasizes the irreplaceable role of genetic testing of the CaSR gene when clinical evaluation is inconclusive.
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Affiliation(s)
- K Zajíčková
- Institute of Endocrinology, Prague, Czech Republic.
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Abstract
The Toxic-metabolic, Idiopathic, Genetic, Autoimmune, Recurrent and severe acute pancreatitis and Obstructive (TIGAR-O) Pancreatitis Risk/Etiology Checklist (TIGAR-O_V1) is a broad classification system that lists the major risk factors and etiologies of recurrent acute pancreatitis, chronic pancreatitis, and overlapping pancreatic disorders with or without genetic, immunologic, metabolic, nutritional, neurologic, metaplastic, or other features. New discoveries and progressive concepts since the 2001 TIGAR-O list relevant to understanding and managing complex pancreatic disorders require an update to TIGAR-O_V2 with both a short (S) and long (L) form. The revised system is designed as a hierarchical checklist for health care workers to quickly document and track specific factors that, alone or in combinations, may contribute to progressive pancreatic disease in individual patients or groups of patients and to assist in treatment selection. The rationale and key clinical considerations are summarized for each updated classification item. Familiarity with the structured format speeds up the completion process and supports thoroughness and consideration of complex or alternative diagnoses during evaluation and serves as a framework for communication. The structured approach also facilitates the new health information technologies that required high-quality data for accurate precision medicine. A use primer accompanies the TIGAR-O_V2 checklist with rationale and comments for health care workers and industries caring for patients with pancreatic diseases.
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