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García-Andrade F, Vigueras-Villaseñor RM, Chávez-Saldaña MD, Rojas-Castañeda JC, Bahena-Ocampo IU, Aréchaga-Ocampo E, Flores-Fortis M, Díaz-Chávez J, Herrera LA, Landero-Huerta DA. Molecular Characterization of Patients with Cryptorchidism: Preliminary Search for an Expression Profile Related to That of Testicular Germ-Cell Tumors. Diagnostics (Basel) 2023; 13:3020. [PMID: 37761387 PMCID: PMC10529510 DOI: 10.3390/diagnostics13183020] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 08/30/2023] [Accepted: 09/09/2023] [Indexed: 09/29/2023] Open
Abstract
Cryptorchidism (CO) is a risk factor for the development of testicular germ-cell tumors (TGCT). This is supported by reports showing the persistence of gonocytes in CO patients. These cells are proposed to be related to the development of germ-cell neoplasia in situ (GCNIS), which is considered the precursor stage/lesion of TGCT. Therefore, it is proposed that some patients with CO could express some molecular markers related to TGCT. In this study, we analyzed testicular tissue samples from CO, TGCT, and controls. We determined the expression of POU5F1, PLAP, and KIT by immunohistochemistry and that of the hsa-miR-371-373 cluster, hsa-miR-367, and LATS2, PTEN, and IGFR1 genes by RT-qPCR. We then carried out a bioinformatic analysis to identify other possible candidate genes as tumor biomarkers. We found that 16.7% (2/12) of the CO patients presented increased expression of POU5F1, KIT, PLAP, hsa-miR-371-373, and hsa-miR-367 and decreased expression of LATS2 and IGF1R. Finally, the genes ARID4B, GALNT3, and KPNA6 were identified as other possible candidate tumor biomarkers. This is the first report describing the expression of the hsa-miR-371-373 cluster, hsa-miR-367, LATS2, and IGF1R in the testicular tissues of two CO patients with cells immune-positive to POU5F1, PLAP, and KIT, which is similar to what is observed in TGCT.
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Affiliation(s)
- Fabiola García-Andrade
- Laboratorio de Biología de la Reproducción, Instituto Nacional de Pediatría, Ciudad de Mexico 04530, Mexico
- Posgrado en Biología Experimental, Universidad Autónoma Metropolitana, Unidad Iztapalapa, Ciudad de Mexico 09310, Mexico
| | | | | | | | - Ivan Uriel Bahena-Ocampo
- Departamento de Ciencias de la Salud, Universidad Autónoma Metropolitana, Unidad Iztapalapa, Ciudad de Mexico 09310, Mexico
| | - Elena Aréchaga-Ocampo
- Departamento de Ciencias Naturales, Universidad Autónoma Metropolitana, Unidad Cuajimalpa, Ciudad de Mexico 05348, Mexico
| | - Mauricio Flores-Fortis
- Posgrado en Ciencias Naturales e Ingeniería, Universidad Autónoma Metropolitana, Unidad Cuajimalpa, Ciudad de Mexico 05348, Mexico
| | - José Díaz-Chávez
- Unidad de Investigación en Cáncer, Instituto de Investigaciones Biomédicas-Universidad Nacional Autónoma de México, Instituto Nacional de Cancerología, Ciudad de Mexico 14080, Mexico
| | - Luis Alonso Herrera
- Unidad de Investigación en Cáncer, Instituto de Investigaciones Biomédicas-Universidad Nacional Autónoma de México, Instituto Nacional de Cancerología, Ciudad de Mexico 14080, Mexico
- Escuela de Medicina y Ciencias de la Salud-Tecnológico de Monterrey, Ciudad de Mexico 14380, Mexico
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Hassan N, Gregson CL, Tang H, van der Kamp M, Leo P, McInerney‐Leo AM, Zheng J, Brandi ML, Tang JCY, Fraser W, Stone MD, Grundberg E, Brown MA, Duncan EL, Tobias JH. Rare and Common Variants in GALNT3 May Affect Bone Mass Independently of Phosphate Metabolism. J Bone Miner Res 2023; 38:678-691. [PMID: 36824040 PMCID: PMC10729283 DOI: 10.1002/jbmr.4795] [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: 09/19/2022] [Revised: 02/15/2023] [Accepted: 02/22/2023] [Indexed: 02/25/2023]
Abstract
Anabolic treatment options for osteoporosis remain limited. One approach to discovering novel anabolic drug targets is to identify genetic causes of extreme high bone mass (HBM). We investigated a pedigree with unexplained HBM within the UK HBM study, a national cohort of probands with HBM and their relatives. Whole exome sequencing (WES) in a family with HBM identified a rare heterozygous missense variant (NM_004482.4:c.1657C > T, p.Arg553Trp) in GALNT3, segregating appropriately. Interrogation of data from the UK HBM study and the Anglo-Australasian Osteoporosis Genetics Consortium (AOGC) revealed an unrelated individual with HBM with another rare heterozygous variant (NM_004482.4:c.831 T > A, p.Asp277Glu) within the same gene. In silico protein modeling predicted that p.Arg553Trp would disrupt salt-bridge interactions, causing instability of GALNT3, and that p.Asp277Glu would disrupt manganese binding and consequently GALNT3 catalytic function. Bi-allelic loss-of-function GALNT3 mutations alter FGF23 metabolism, resulting in hyperphosphatemia and causing familial tumoral calcinosis (FTC). However, bone mineral density (BMD) in FTC cases, when reported, has been either normal or low. Common variants in the GALNT3 locus show genome-wide significant associations with lumbar, femoral neck, and total body BMD. However, no significant associations with BMD are observed at loci coding for FGF23, its receptor FGFR1, or coreceptor klotho. Mendelian randomization analysis, using expression quantitative trait loci (eQTL) data from primary human osteoblasts and genome-wide association studies data from UK Biobank, suggested increased expression of GALNT3 reduces total body, lumbar spine, and femoral neck BMD but has no effect on phosphate concentrations. In conclusion, rare heterozygous loss-of-function variants in GALNT3 may cause HBM without altering phosphate concentration. These findings suggest that GALNT3 may affect BMD through pathways other than FGF23 regulation, the identification of which may yield novel anabolic drug targets for osteoporosis. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Neelam Hassan
- Musculoskeletal Research Unit, Translational Health Sciences, Bristol Medical SchoolUniversity of BristolBristolUK
| | - Celia L. Gregson
- Musculoskeletal Research Unit, Translational Health Sciences, Bristol Medical SchoolUniversity of BristolBristolUK
- MRC Integrated Epidemiology Unit, Population Health Sciences, Bristol Medical SchoolUniversity of BristolBristolUK
| | - Haotian Tang
- MRC Integrated Epidemiology Unit, Population Health Sciences, Bristol Medical SchoolUniversity of BristolBristolUK
| | | | - Paul Leo
- Faculty of Health, Translational Genomics Group, Institute of Health and Biomedical InnovationQueensland University of TechnologyBrisbaneQueenslandAustralia
| | - Aideen M. McInerney‐Leo
- The Faculty of Medicine, Frazer InstituteThe University of QueenslandWoolloongabbaQueenslandAustralia
| | - Jie Zheng
- MRC Integrated Epidemiology Unit, Population Health Sciences, Bristol Medical SchoolUniversity of BristolBristolUK
- Department of Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
- Shanghai National Clinical Research Center for metabolic Diseases, Key Laboratory for Endocrine and Metabolic Diseases of the National Health Commission of the PR ChinaShanghai Jiao Tong University School of MedicineShanghaiChina
- Shanghai Key Laboratory for Endocrine Tumor, State Key Laboratory of Medical Genomics, Ruijin HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
| | | | - Jonathan C. Y. Tang
- Norwich Medical SchoolUniversity of East AngliaNorwichUK
- Clinical Biochemistry, Departments of Laboratory MedicineNorfolk and Norwich University Hospital NHS Foundation TrustNorwichUK
| | - William Fraser
- Norwich Medical SchoolUniversity of East AngliaNorwichUK
- Department of Diabetes, Endocrinology and Clinical BiochemistryNorfolk and Norwich University Hospital NHS Foundation TrustNorwichUK
| | - Michael D. Stone
- University Hospital LlandoughCardiff & Vale University Health BoardCardiffUK
| | - Elin Grundberg
- Genomic Medicine CenterChildren's Mercy Kansas CityKansas CityMissouriUSA
| | | | | | - Emma L. Duncan
- Department of Twin Research and Genetic Epidemiology, School of Life Course & Population Sciences, Faculty of Life Sciences and MedicineKing's College LondonLondonUK
| | - Jonathan H. Tobias
- Musculoskeletal Research Unit, Translational Health Sciences, Bristol Medical SchoolUniversity of BristolBristolUK
- MRC Integrated Epidemiology Unit, Population Health Sciences, Bristol Medical SchoolUniversity of BristolBristolUK
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Li J, Guo B, Zhang W, Yue S, Huang S, Gao S, Ma J, Cipollo JF, Yang S. Recent advances in demystifying O-glycosylation in health and disease. Proteomics 2022; 22:e2200156. [PMID: 36088641 DOI: 10.1002/pmic.202200156] [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: 04/23/2022] [Revised: 08/30/2022] [Accepted: 09/02/2022] [Indexed: 11/09/2022]
Abstract
O-Glycosylation is one of the most common protein post-translational modifications (PTM) and plays an essential role in the pathophysiology of diseases. However, the complexity of O-glycosylation and the lack of specific enzymes for the processing of O-glycans and their O-glycopeptides make O-glycosylation analysis challenging. Recently, research on O-glycosylation has received attention owing to technological innovation and emerging O-glycoproteases. Several serine/threonine endoproteases have been found to specifically cleave O-glycosylated serine or threonine, allowing for the systematic analysis of O-glycoproteins. In this review, we first assessed the field of protein O-glycosylation over the past decade and used bibliometric analysis to identify keywords and emerging trends. We then summarized recent advances in O-glycosylation, covering several aspects: O-glycan release, site-specific elucidation of intact O-glycopeptides, identification of O-glycosites, characterization of different O-glycoproteases, mass spectrometry (MS) fragmentation methods for site-specific O-glycosylation assignment, and O-glycosylation data analysis. Finally, the role of O-glycosylation in health and disease was discussed.
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Affiliation(s)
- Jiajia Li
- Center for Clinical Mass Spectrometry, College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu, China
| | - Bo Guo
- Jiangsu Key Laboratory of Marine Pharmaceutical Compound Screening, Jiangsu Key Laboratory of Marine Biological Resources and Environment, Co-Innovation Center of Jiangsu Marine Bio-industry Technology, School of Pharmacy, Jiangsu Ocean University, Lianyungang, China
| | - Wenqi Zhang
- Center for Clinical Mass Spectrometry, College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu, China
| | - Shuang Yue
- Center for Clinical Mass Spectrometry, College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu, China
| | - Shan Huang
- Center for Clinical Mass Spectrometry, College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu, China
| | - Song Gao
- Jiangsu Key Laboratory of Marine Pharmaceutical Compound Screening, Jiangsu Key Laboratory of Marine Biological Resources and Environment, Co-Innovation Center of Jiangsu Marine Bio-industry Technology, School of Pharmacy, Jiangsu Ocean University, Lianyungang, China
| | - Junfeng Ma
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Georgetown University, Washington, DC, USA
| | - John F Cipollo
- Laboratory of Bacterial Polysaccharides, Division of Bacterial, Parasitic and Allergenic Products, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland, USA
| | - Shuang Yang
- Center for Clinical Mass Spectrometry, College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu, China
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Kato K, Hansen L, Clausen H. Polypeptide N-acetylgalactosaminyltransferase-Associated Phenotypes in Mammals. Molecules 2021; 26:5504. [PMID: 34576978 PMCID: PMC8472655 DOI: 10.3390/molecules26185504] [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: 07/23/2021] [Revised: 09/07/2021] [Accepted: 09/08/2021] [Indexed: 01/31/2023] Open
Abstract
Mucin-type O-glycosylation involves the attachment of glycans to an initial O-linked N-acetylgalactosamine (GalNAc) on serine and threonine residues on proteins. This process in mammals is initiated and regulated by a large family of 20 UDP-GalNAc: polypeptide N-acetylgalactosaminyltransferases (GalNAc-Ts) (EC 2.4.1.41). The enzymes are encoded by a large gene family (GALNTs). Two of these genes, GALNT2 and GALNT3, are known as monogenic autosomal recessive inherited disease genes with well characterized phenotypes, whereas a broad spectrum of phenotypes is associated with the remaining 18 genes. Until recently, the overlapping functionality of the 20 members of the enzyme family has hindered characterizing the specific biological roles of individual enzymes. However, recent evidence suggests that these enzymes do not have full functional redundancy and may serve specific purposes that are found in the different phenotypes described. Here, we summarize the current knowledge of GALNT and associated phenotypes.
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Affiliation(s)
- Kentaro Kato
- Department of Eco-Epidemiology, Institute of Tropical Medicine, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan
- School of Tropical Medicine and Global Health, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan
| | - Lars Hansen
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Mærsk Building, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark;
| | - Henrik Clausen
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Mærsk Building, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark;
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Ito N, Fukumoto S. Congenital Hyperphosphatemic Conditions Caused by the Deficient Activity of FGF23. Calcif Tissue Int 2021; 108:104-115. [PMID: 31965220 DOI: 10.1007/s00223-020-00659-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Accepted: 01/09/2020] [Indexed: 02/07/2023]
Abstract
Congenital diseases that could result in hyperphosphatemia at an early age include hyperphosphatemic familial tumoral calcinosis (HFTC)/hyperostosis-hyperphosphatemia syndrome (HHS) and congenital hypoparathyroidism/pseudohypoparathyroidism due to the insufficient activity of fibroblast growth factor (FGF) 23 and parathyroid hormone. HFTC/HHS is a rare autosomal recessive disease caused by inactivating mutations in the FGF23, UDP-N-acetyl-alpha-D-galactosamine:polypeptide N-acetylgalactosaminyltransferase 3 (GALNT3), or Klotho (KL) genes, resulting in the excessive cleavage of active intact FGF23 (FGF23, GALNT3) or increased resistance to the action of FGF23 (KL). Massive ectopic calcification, known as tumoral calcinosis (TC), is seen in periarticular soft tissues, typically in the hip, elbow, and shoulder in HFTC/HHS, reducing the range of motion. However, other regions, such as the eye, intestine, vasculature, and testis, are also targets of ectopic calcification. The other symptoms of HFTC/HHS are painful hyperostosis of the lower legs, dental abnormalities, and systemic inflammation. Low phosphate diets, phosphate binders, and phosphaturic reagents such as acetazolamide are the treatment options for HFTC/HHS and have various consequences, which warrant the development of novel therapeutics involving recombinant FGF23.
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Affiliation(s)
- Nobuaki Ito
- Division of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo, Japan.
| | - Seiji Fukumoto
- Fujii Memorial Institute of Medical Sciences, Institute of Advanced Medical Sciences, Tokushima University, Tokushima, Japan
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Boyce AM, Lee AE, Roszko KL, Gafni RI. Hyperphosphatemic Tumoral Calcinosis: Pathogenesis, Clinical Presentation, and Challenges in Management. Front Endocrinol (Lausanne) 2020; 11:293. [PMID: 32457699 PMCID: PMC7225339 DOI: 10.3389/fendo.2020.00293] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 04/20/2020] [Indexed: 02/02/2023] Open
Abstract
Hyperphosphatemic familial tumoral calcinosis (HFTC) is a rare and disabling disorder of fibroblast growth factor 23 (FGF23) deficiency or resistance. The disorder is manifest by hyperphosphatemia, inappropriately increased tubular reabsorption of phosphate and 1,25-dihydroxy-Vitamin D, and ectopic calcifications. HFTC has been associated with autosomal recessive pathogenic variants in: (1) the gene encoding FGF23; (2) GALNT3, which encodes a protein responsible for FGF23 glycosylation; and (3) KL, the gene encoding KLOTHO, a critical co-receptor for FGF23 signaling. An acquired autoimmune form of hyperphosphatemic tumoral calcinosis has also been reported. Periarticular tumoral calcinosis is the primary cause of disability in HFTC, leading to pain, reduced range-of-motion, and impaired physical function. Inflammatory disease is also prominent, including diaphysitis with cortical hyperostosis. Multiple treatment strategies have attempted to manage blood phosphate, reduce pain and inflammation, and address calcifications and their complications. Unfortunately, efficacy data are limited to case reports and small cohorts, and no clearly effective therapies have been identified. The purpose of this review is to provide a background on pathogenesis and clinical presentation in HFTC, discuss current approaches to clinical management, and outline critical areas of need for future research.
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Chakhtoura M, Ramnitz MS, Khoury N, Nemer G, Shabb N, Abchee A, Berberi A, Hourani M, Collins M, Ichikawa S, El Hajj Fuleihan G. Hyperphosphatemic familial tumoral calcinosis secondary to fibroblast growth factor 23 (FGF23) mutation: a report of two affected families and review of the literature. Osteoporos Int 2018; 29:1987-2009. [PMID: 29923062 DOI: 10.1007/s00198-018-4574-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 05/14/2018] [Indexed: 01/20/2023]
Abstract
Hyperphosphatemic familial tumoral calcinosis (HFTC), secondary to fibroblast growth factor 23 (FGF23) gene mutation, is a rare genetic disorder characterized by recurrent calcified masses. We describe young Lebanese cousins presenting with HFTC, based on a retrospective chart review and a prospective case study. In addition, we present a comprehensive review on the topic, based on a literature search conducted in PubMed and Google Scholar, in 2014 and updated in December 2017. While the patients had the same previously reported FGF23 gene mutation (homozygous c.G367T variant in exon 3 leading to a missense mutation), they presented with variable severity and age of disease onset (at 4 years in patient 1 and at 23 years in patient 2). A review of the literature revealed several potential patho-physiologic pathways of HFTC clinical manifestations, some of which may be independent of hyperphosphatemia. Most available treatment options aim at reducing serum phosphate level, by stimulating renal excretion or by inhibiting intestinal absorption. HFTC is a challenging disease. While the available medical treatment has a limited and inconsistent effect on disease symptomatology, surgical resection of calcified masses remains the last resort. Research is needed to determine the safety and efficacy of FGF23 replacement or molecular therapy, targeting the specific genetic aberration. Hyperphosphatemic familial tumoral calcinosis is a rare genetic disorder characterized by recurrent calcified masses, in addition to other visceral, skeletal, and vascular manifestations. It remains a very challenging disease.
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Affiliation(s)
- M Chakhtoura
- Calcium Metabolism and Osteoporosis Program, WHO Collaborating Center for Metabolic Bone Disorders, American University of Beirut Medical Center, Beirut, Lebanon.
| | - M S Ramnitz
- Section on Skeletal Disorders and Mineral Homeostasis, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
| | - N Khoury
- Department of Radiology, American University of Beirut Medical Center, Beirut, Lebanon
| | - G Nemer
- Department of Biochemistry and Molecular Genetics, American University of Beirut Medical Center, Beirut, Lebanon
| | - N Shabb
- Department of Pathology and Laboratory Medicine, American University of Beirut Medical Center, Beirut, Lebanon
| | - A Abchee
- Department of Internal Medicine, American University of Beirut Medical Center, Beirut, Lebanon
| | - A Berberi
- Department of Internal Medicine, American University of Beirut Medical Center, Beirut, Lebanon
| | - M Hourani
- Department of Radiology, American University of Beirut Medical Center, Beirut, Lebanon
| | - M Collins
- Section on Skeletal Disorders and Mineral Homeostasis, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
| | - S Ichikawa
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - G El Hajj Fuleihan
- Calcium Metabolism and Osteoporosis Program, WHO Collaborating Center for Metabolic Bone Disorders, American University of Beirut Medical Center, Beirut, Lebanon
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Identification of two novel mutations in the GALNT3 gene in a Chinese family with hyperphosphatemic familial tumoral calcinosis. Bone Res 2016; 4:16038. [PMID: 27867679 PMCID: PMC5100662 DOI: 10.1038/boneres.2016.38] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 08/23/2016] [Indexed: 12/15/2022] Open
Abstract
Hyperphosphatemic familial tumoral calcinosis (HFTC) is a rare, autosomal recessive genetic disease. This disease is characterized by the progressive calcification of soft tissues leading to symptoms of pressure and hyperphosphatemia but normal concentrations of serum calcium with or without an elevation of 1,25-dihydroxyvitamin D3 levels.HFTC is caused by loss-of-function mutations in the GALNT3, FGF23 or KL genes. Here, we identified two novel mutations in the GALNT3 gene in a Chinese family with HFTC. Identification of a novel genotype in HFTC provides clues for understanding the phenotype-genotype relationships in HFTC and may assist not only in the clinical diagnosis of HFTC but also in the interpretation of the genetic information used for prenatal diagnosis and genetic counseling.
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Masi L, Beltrami G, Ottanelli S, Franceschelli F, Gozzini A, Zonefrati R, Galli G, Ciuffi S, Mavilia C, Giusti F, Marcucci G, Cioppi F, Colli E, Fossi C, Franchi A, Casentini C, Capanna R, Brandi ML. Human Preosteoblastic Cell Culture from a Patient with Severe Tumoral Calcinosis-Hyperphosphatemia Due to a New GALNT3 Gene Mutation: Study of In Vitro Mineralization. Calcif Tissue Int 2015; 96:438-52. [PMID: 25899975 DOI: 10.1007/s00223-015-9974-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Accepted: 02/24/2015] [Indexed: 02/08/2023]
Abstract
Human disorders of phosphate (Pi) handling and skeletal mineralization represent a group of rare bone diseases. One of these disease is tumoral calcinosis (TC). In this study, we present the case of a patient with TC with a new GALNT3 gene mutation. We also performed functional studies using an in vitro cellular model. Genomic DNA was extracted from peripheral blood collected from a teenage Caucasian girl affected by TC, and from her parents. A higher capability to form mineralization nodules in vitro was found in human preosteoblastic cells of mutant when compared to wild-type controls. We found a novel homozygous inactivating splice site mutation in intron I (c.516-2a>g). A higher capability to form mineralization nodules in vitro was found in the mutant cells in human preosteoblastic cells when compared to wild-type controls. Understanding the functional significance and molecular physiology of this novel mutation will help to define the role of FGF23 in the control of Pi homeostasis in normal and in pathological conditions.
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Affiliation(s)
- L Masi
- Metabolic Bone Diseases Unit AOUC-Careggi, Department of Orthopedics, University of Florence, Largo Palagi, 1, 50134, Florence, Italy
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Favia G, Lacaita MG, Limongelli L, Tempesta A, Laforgia N, Cazzolla AP, Maiorano E. Hyperphosphatemic familial tumoral calcinosis: odontostomatologic management and pathological features. AMERICAN JOURNAL OF CASE REPORTS 2014; 15:569-75. [PMID: 25537063 PMCID: PMC4278695 DOI: 10.12659/ajcr.892113] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND Hyperphosphatemic familial tumoral calcinosis (HFTC) is to a rare autosomal recessive disorder characterized by cutaneous and sub-cutaneous calcified masses, usually adjacent to large joints. The aim of the current study was to report on the clinico-pathological features of a patient with HFCT, with emphasis on alterations in the jawbones and teeth and the subsequent therapeutic interventions. CASE REPORT A 13-year-old male patient with HFTC diagnosis came to our attention for dental anomalies and maxillary and mandibular hypoplasia. OPT highlighted multiple impacted teeth, short and bulbous teeth, and pulp chamber and canal obliterations. Lateral cephalometric radiograms pointed out retrusion of both jaws, skeletal class II malocclusion, and deep-bite. He underwent orthopedic, orthodontic, conservative, and surgical treatments, allowing the correction of maxillo-facial and dental abnormalities and dysmorphisms without adverse effects. The surgical samples were sent for conventional and confocal laser scanning microscope (CLSM) histopathological examination, which highlighted several metaplastic micro- and macro-calcifications in the soft tissues, and typical islands of homogenous, non-tubular, dentino-osteoid calcified structures in dentinal tissues. CONCLUSIONS The management of maxillo-facial abnormalities in patients affected by HFTC is very difficult and, requires a combined therapeutic approach. To date, very few indications have been published in the literature.
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Affiliation(s)
- Gianfranco Favia
- Department of Interdisciplinary Medicine, Complex Operating Unit of Odontostomatology, Aldo Moro University, Barii, Italy
| | - Maria Grazia Lacaita
- Department of Interdisciplinary Medicine, Complex Operating Unit of Odontostomatology, Aldo Moro University, Barii, Italy
| | - Luisa Limongelli
- Department of Interdisciplinary Medicine, Complex Operating Unit of Odontostomatology, Aldo Moro University, Barii, Italy
| | - Angela Tempesta
- Department of Interdisciplinary Medicine, Complex Operating Unit of Odontostomatology, Aldo Moro University, Barii, Italy
| | - Nicola Laforgia
- Department of Biomedical Science and Human Oncology, Complex Operating Unit of Pediatrics, Aldo Moro University, Barii, Italy
| | - Angela Pia Cazzolla
- Department of Interdisciplinary Medicine, Complex Operating Unit of Odontostomatology, Aldo Moro University, Barii, Italy
| | - Eugenio Maiorano
- Department of Emergency and Organ Transplantation, Pathological Anatomy, Aldo Moro University, Barii, Italy
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Rafaelsen S, Johansson S, Ræder H, Bjerknes R. Long-term clinical outcome and phenotypic variability in hyperphosphatemic familial tumoral calcinosis and hyperphosphatemic hyperostosis syndrome caused by a novel GALNT3 mutation; case report and review of the literature. BMC Genet 2014; 15:98. [PMID: 25249269 PMCID: PMC4181413 DOI: 10.1186/s12863-014-0098-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Accepted: 09/04/2014] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Hyperphosphatemic Familial Tumoral Calcinosis (HFTC) and Hyperphosphatemic Hyperostosis Syndrome (HHS) are associated with autosomal recessive mutations in three different genes, FGF23, GALNT3 and KL, leading to reduced levels of fibroblast growth factor 23 (FGF23) and subsequent clinical effects. RESULTS We describe a consanguineous family with two affected siblings with HFTC and HHS caused by a novel homozygous G-to T substitution in exon 3 of GALNT3 (c.767 G > T; p.Gly256Val), demonstrating great phenotypic variation and long asymptomatic intervals. Calcific tumors appeared at 14 years of age in the male, and the female displayed episodic diaphysitis from age 9 years. Symptoms of eye involvement were present in both from childhood, and progressed into band keratopathy in the female. Abnormal dental roots and tooth loss, as well as myalgia were present in both from their mid-twenties, while the female also had calcifications in the placenta, the iliac vessels and thyroid cartilage. New calcific tumors appeared more than 20 years after the initial episodes, delaying diagnosis and treatment until the ages of 37 and 50 years, respectively. Both siblings had elevated serum phosphate levels, inappropriately elevated tubular maximum phosphate reabsorption per unit glomerular filtration rate (TmP/GFR), reduced levels of intact FGF23 and increased levels of c-terminal FGF23. Review of all 54 previously published cases of GALNT3, FGF23, and KL associated HFTC and HHS demonstrated that more subjects than previously recognized have a combined phenotype. CONCLUSION We have described HFTC and HHS in a consanguineous Caucasian family with a novel GALNT3 mutation, demonstrating new phenotypic features and significant variability in the natural course of the disease. A review of the literature, show that more subjects than previously recognized have a combined phenotype of HFTC and HHS. HHS and HFTC are two distinct phenotypes in a spectrum of GALNT3 mutation related calcification disorders, where the additional factors determining the phenotypic expression, are yet to be clarified.
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Affiliation(s)
- Silje Rafaelsen
- />Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Stefan Johansson
- />Department of Clinical Science, University of Bergen, Bergen, Norway
- />Center of Medical Genetics and Molecular Medicine, Haukeland University Hospital, Bergen, Norway
| | - Helge Ræder
- />Department of Clinical Science, University of Bergen, Bergen, Norway
- />Department of Pediatrics, Haukeland University Hospital, Bergen, Norway
| | - Robert Bjerknes
- />Department of Clinical Science, University of Bergen, Bergen, Norway
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12
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Osteocyte Communication with the Kidney Via the Production of FGF23: Remote Control of Phosphate Homeostasis. Clin Rev Bone Miner Metab 2014. [DOI: 10.1007/s12018-014-9155-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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13
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Mullooly C, Hickerton B, Weston R, Woolley PD. Testicular microlithiasis: is it significant? Int J STD AIDS 2013; 23:620-2. [PMID: 23033512 DOI: 10.1258/ijsa.2012.011444] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Previously considered to be a benign finding on scrotal ultrasonography, testicular microlithiasis (TM) is now recognized as a condition associated with the development of testicular neoplasia. Despite this the management of TM remains unclear. We review the evidence for this association and suggested management strategies.
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Affiliation(s)
- C Mullooly
- Department of Sexual Medicine and HIV, University Hospitals of South Manchester, West Didsbury, Manchester, UK.
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14
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Miyazaki T, Mori M, Yoshida CA, Ito C, Yamatoya K, Moriishi T, Kawai Y, Komori H, Kawane T, Izumi SI, Toshimori K, Komori T. Galnt3 deficiency disrupts acrosome formation and leads to oligoasthenoteratozoospermia. Histochem Cell Biol 2013; 139:339-54. [PMID: 23052838 DOI: 10.1007/s00418-012-1031-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/10/2012] [Indexed: 12/18/2022]
Abstract
Galnt3 belongs to the GalNAc transferase gene family involved in the initiation of mucin-type O-glycosylation. Male Galnt3-deficient (Galnt3(-/-)) mice were infertile, as previously reported by Ichikawa et al. (2009). To investigate the involvement of Galnt3 in spermatogenesis, we examined the differentiation of germ cells in Galnt3(-/-) mice. Galnt3 mRNA was most highly expressed in testis, and Galnt3 protein was localized in the cis-medial parts of the Golgi stacks of spermatocytes and spermatids in the seminiferous tubules. Spermatozoa in Galnt3(-/-) mice were rare and immotile, and most of them had deformed round heads. They exhibited abnormal acrosome and disturbed mitochondria arrangement in the flagella. At the cap phase, proacrosomal vesicles of various sizes, which had not coalesced to form a single acrosomal vesicle, were attached to the nucleus in Galnt3(-/-) mice. TUNEL-positive cells were increased in the seminiferous tubules. The binding of VVA lectin, which recognizes the Tn antigen (GalNAc-O-Ser/Thr), in the acrosomal regions of spermatids and spermatozoa in Galnt3(-/-) mice was drastically reduced. Equatorin is a N, O-sialoglycoprotein localized in the acrosomal membrane and is suggested to be involved in sperm-egg interaction. Immunohistochemical and Western blot analyses showed a drastic reduction in the reactivity with MN9 antibody, which recognizes the O-glycosylated moiety of equatorin and inhibits sperm-egg interaction. These findings indicate that deficiency of Galnt3 results in a severe reduction of mucin-type O-glycans in spermatids and causes impaired acrosome formation, leading to oligoasthenoteratozoospermia, and suggest that Galnt3 may also be involved in the process of fertilization through the O-glycosylation of equatorin.
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Affiliation(s)
- Toshihiro Miyazaki
- Department of Cell Biology, Unit of Basic Medical Sciences, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki 852-8588, Japan
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15
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Schjoldager KTBG, Clausen H. Site-specific protein O-glycosylation modulates proprotein processing - deciphering specific functions of the large polypeptide GalNAc-transferase gene family. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1820:2079-94. [PMID: 23022508 DOI: 10.1016/j.bbagen.2012.09.014] [Citation(s) in RCA: 149] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Revised: 09/17/2012] [Accepted: 09/19/2012] [Indexed: 01/18/2023]
Abstract
BACKGROUND Posttranslational modifications (PTMs) greatly expand the function and regulation of proteins, and glycosylation is the most abundant and diverse PTM. Of the many different types of protein glycosylation, one is quite unique; GalNAc-type (or mucin-type) O-glycosylation, where biosynthesis is initiated in the Golgi by up to twenty distinct UDP-N-acetyl-α-d-galactosamine:polypeptide N-acetylgalactosaminyltransferases (GalNAc-Ts). These GalNAc-Ts are differentially expressed in cells and have different (although partly overlapping) substrate specificities, which provide for both unique functions and considerable redundancy. Recently we have begun to uncover human diseases associated with deficiencies in GalNAc-T genes (GALNTs). Thus deficiencies in individual GALNTs produce cell and protein specific effects and subtle distinct phenotypes such as hyperphosphatemia with hyperostosis (GALNT3) and dysregulated lipid metabolism (GALNT2). These phenotypes appear to be caused by deficient site-specific O-glycosylation that co-regulates proprotein convertase (PC) processing of FGF23 and ANGPTL3, respectively. SCOPE OF REVIEW Here we summarize recent progress in uncovering the interplay between human O-glycosylation and protease regulated processing and describes other important functions of site-specific O-glycosylation in health and disease. MAJOR CONCLUSIONS Site-specific O-glycosylation modifies pro-protein processing and other proteolytic events such as ADAM processing and thus emerges as an important co-regulator of limited proteolytic processing events. GENERAL SIGNIFICANCE Our appreciation of this function may have been hampered by our sparse knowledge of the O-glycoproteome and in particular sites of O-glycosylation. New strategies for identification of O-glycoproteins have emerged and recently the concept of SimpleCells, i.e. human cell lines made deficient in O-glycan extension by zinc finger nuclease gene targeting, was introduced for broad O-glycoproteome analysis.
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16
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Esapa CT, Head RA, Jeyabalan J, Evans H, Hough TA, Cheeseman MT, McNally EG, Carr AJ, Thomas GP, Brown MA, Croucher PI, Brown SDM, Cox RD, Thakker RV. A mouse with an N-Ethyl-N-nitrosourea (ENU) Induced Trp589Arg Galnt3 mutation represents a model for hyperphosphataemic familial tumoural calcinosis. PLoS One 2012; 7:e43205. [PMID: 22912827 PMCID: PMC3418237 DOI: 10.1371/journal.pone.0043205] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Accepted: 07/18/2012] [Indexed: 01/09/2023] Open
Abstract
Mutations of UDP-N-acetyl-alpha-D-galactosamine polypeptide N-acetyl galactosaminyl transferase 3 (GALNT3) result in familial tumoural calcinosis (FTC) and the hyperostosis-hyperphosphataemia syndrome (HHS), which are autosomal recessive disorders characterised by soft-tissue calcification and hyperphosphataemia. To facilitate in vivo studies of these heritable disorders of phosphate homeostasis, we embarked on establishing a mouse model by assessing progeny of mice treated with the chemical mutagen N-ethyl-N-nitrosourea (ENU), and identified a mutant mouse, TCAL, with autosomal recessive inheritance of ectopic calcification, which involved multiple tissues, and hyperphosphataemia; the phenotype was designated TCAL and the locus, Tcal. TCAL males were infertile with loss of Sertoli cells and spermatozoa, and increased testicular apoptosis. Genetic mapping localized Tcal to chromosome 2 (62.64-71.11 Mb) which contained the Galnt3. DNA sequence analysis identified a Galnt3 missense mutation (Trp589Arg) in TCAL mice. Transient transfection of wild-type and mutant Galnt3-enhanced green fluorescent protein (EGFP) constructs in COS-7 cells revealed endoplasmic reticulum retention of the Trp589Arg mutant and Western blot analysis of kidney homogenates demonstrated defective glycosylation of Galnt3 in Tcal/Tcal mice. Tcal/Tcal mice had normal plasma calcium and parathyroid hormone concentrations; decreased alkaline phosphatase activity and intact Fgf23 concentrations; and elevation of circulating 1,25-dihydroxyvitamin D. Quantitative reverse transcriptase-PCR (qRT-PCR) revealed that Tcal/Tcal mice had increased expression of Galnt3 and Fgf23 in bone, but that renal expression of Klotho, 25-hydroxyvitamin D-1α-hydroxylase (Cyp27b1), and the sodium-phosphate co-transporters type-IIa and -IIc was similar to that in wild-type mice. Thus, TCAL mice have the phenotypic features of FTC and HHS, and provide a model for these disorders of phosphate metabolism.
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Affiliation(s)
- Christopher T. Esapa
- Academic Endocrine Unit, Nuffield Department of Clinical Medicine, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford, United Kingdom
- Medical Research Council (MRC) Mammalian Genetics Unit and Mary Lyon Centre, MRC Harwell, Harwell Science and Innovation Campus, United Kingdom
| | - Rosie A. Head
- Academic Endocrine Unit, Nuffield Department of Clinical Medicine, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford, United Kingdom
- Medical Research Council (MRC) Mammalian Genetics Unit and Mary Lyon Centre, MRC Harwell, Harwell Science and Innovation Campus, United Kingdom
| | - Jeshmi Jeyabalan
- Academic Endocrine Unit, Nuffield Department of Clinical Medicine, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford, United Kingdom
| | - Holly Evans
- The Mellanby Centre for Bone Research, Department of Human Metabolism, University of Sheffield, Sheffield, United Kingdom
| | - Tertius A. Hough
- Medical Research Council (MRC) Mammalian Genetics Unit and Mary Lyon Centre, MRC Harwell, Harwell Science and Innovation Campus, United Kingdom
| | - Michael T. Cheeseman
- Medical Research Council (MRC) Mammalian Genetics Unit and Mary Lyon Centre, MRC Harwell, Harwell Science and Innovation Campus, United Kingdom
| | - Eugene G. McNally
- Department of Radiology, Nuffield Orthopaedic Centre and Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, United Kingdom
| | - Andrew J. Carr
- NIHR Biomedical Research Unit, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, United Kingdom
| | - Gethin P. Thomas
- University of Queensland Diamantina Institute, Princess Alexandra Hospital, University of Queensland, Australia
| | - Matthew A. Brown
- University of Queensland Diamantina Institute, Princess Alexandra Hospital, University of Queensland, Australia
| | - Peter I. Croucher
- The Mellanby Centre for Bone Research, Department of Human Metabolism, University of Sheffield, Sheffield, United Kingdom
- Garvan Institute for Medical Research, Sydney, Australia
| | - Steve D. M. Brown
- Medical Research Council (MRC) Mammalian Genetics Unit and Mary Lyon Centre, MRC Harwell, Harwell Science and Innovation Campus, United Kingdom
| | - Roger D. Cox
- Medical Research Council (MRC) Mammalian Genetics Unit and Mary Lyon Centre, MRC Harwell, Harwell Science and Innovation Campus, United Kingdom
| | - Rajesh V. Thakker
- Academic Endocrine Unit, Nuffield Department of Clinical Medicine, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford, United Kingdom
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17
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Bennett EP, Mandel U, Clausen H, Gerken TA, Fritz TA, Tabak LA. Control of mucin-type O-glycosylation: a classification of the polypeptide GalNAc-transferase gene family. Glycobiology 2012; 22:736-56. [PMID: 22183981 PMCID: PMC3409716 DOI: 10.1093/glycob/cwr182] [Citation(s) in RCA: 591] [Impact Index Per Article: 49.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2011] [Revised: 12/14/2011] [Accepted: 12/14/2011] [Indexed: 12/15/2022] Open
Abstract
Glycosylation of proteins is an essential process in all eukaryotes and a great diversity in types of protein glycosylation exists in animals, plants and microorganisms. Mucin-type O-glycosylation, consisting of glycans attached via O-linked N-acetylgalactosamine (GalNAc) to serine and threonine residues, is one of the most abundant forms of protein glycosylation in animals. Although most protein glycosylation is controlled by one or two genes encoding the enzymes responsible for the initiation of glycosylation, i.e. the step where the first glycan is attached to the relevant amino acid residue in the protein, mucin-type O-glycosylation is controlled by a large family of up to 20 homologous genes encoding UDP-GalNAc:polypeptide GalNAc-transferases (GalNAc-Ts) (EC 2.4.1.41). Therefore, mucin-type O-glycosylation has the greatest potential for differential regulation in cells and tissues. The GalNAc-T family is the largest glycosyltransferase enzyme family covering a single known glycosidic linkage and it is highly conserved throughout animal evolution, although absent in bacteria, yeast and plants. Emerging studies have shown that the large number of genes (GALNTs) in the GalNAc-T family do not provide full functional redundancy and single GalNAc-T genes have been shown to be important in both animals and human. Here, we present an overview of the GalNAc-T gene family in animals and propose a classification of the genes into subfamilies, which appear to be conserved in evolution structurally as well as functionally.
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Affiliation(s)
- Eric P Bennett
- Department of Odontology, Copenhagen Center for Glycomics, University of Copenhagen, Nørre Alle 20, DK-2200 Copenhagen N, Denmark.
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18
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Farrow EG, Imel EA, White KE. Miscellaneous non-inflammatory musculoskeletal conditions. Hyperphosphatemic familial tumoral calcinosis (FGF23, GALNT3 and αKlotho). Best Pract Res Clin Rheumatol 2011; 25:735-47. [PMID: 22142751 PMCID: PMC3233725 DOI: 10.1016/j.berh.2011.10.020] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2011] [Accepted: 10/13/2011] [Indexed: 11/18/2022]
Abstract
Familial tumoral calcinosis (TC) is a rare disorder distinguished by the development of ectopic and vascular calcified masses that occur in settings of hyperphosphatemia (hFTC) and normophosphatemia (nFTC). Serum phosphorus concentrations are relatively tightly controlled by interconnected endocrine activity at the level of the intestine, kidney, and skeleton. Discovering the molecular causes for heritable forms of hFTC has shed new light on the regulation of serum phosphate balance. This review will focus upon the genetic basis and clinical approaches for hFTC, due to genes that are related to the phosphaturic hormone fibroblast growth factor-23 (FGF23). These include FGF23 itself, an FGF23-glycosylating enzyme (GALNT3), and the FGF23 co-receptor α-Klotho (αKL). Our understanding of the molecular basis of hFTC will, in the short term, aid in understanding normal phosphate balance, and in the future, provide potential insight into the design of novel therapeutic strategies for both rare and common disorders of phosphate metabolism.
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Affiliation(s)
- Emily G. Farrow
- Departments of Medical and Molecular Genetics, IN, 46202 USA
| | - Erik A. Imel
- Medicine Indiana University School of Medicine Indianapolis, IN, 46202 USA
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19
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Yancovitch A, Hershkovitz D, Indelman M, Galloway P, Whiteford M, Sprecher E, Kılıç E. Novel mutations in GALNT3 causing hyperphosphatemic familial tumoral calcinosis. J Bone Miner Metab 2011; 29:621-5. [PMID: 21347749 DOI: 10.1007/s00774-011-0260-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2010] [Accepted: 01/06/2011] [Indexed: 01/29/2023]
Abstract
Hyperphosphatemic familial tumoral calcinosis (HFTC) is known to be caused by mutations in at least three genes: FGF23, GALNT3 and KL. Two families with two affected members suffering from HFTC were scrutinized for mutations in these candidate genes. We identified in both families homozygous missense mutations affecting highly conserved amino acids in GALNT3. One of the mutations is a novel mutation, whereas the second mutation was reported before in a compound heterozygous state. Our data expand the spectrum of known mutations in GALNT3 and contribute to a better understanding of the phenotypic manifestations of mutations in this gene.
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Affiliation(s)
- Alan Yancovitch
- Center for Translational Genetics, Rappaport Institute for Research in the Medical Sciences, Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
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20
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Masi L. Phosphatonins: new hormones involved in numerous inherited bone disorders. CLINICAL CASES IN MINERAL AND BONE METABOLISM : THE OFFICIAL JOURNAL OF THE ITALIAN SOCIETY OF OSTEOPOROSIS, MINERAL METABOLISM, AND SKELETAL DISEASES 2011; 8:9-13. [PMID: 22461821 PMCID: PMC3279060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Phosphate (Pi) homeostasis is under control of several endocrine factors that play effects on bone, kidney and intestine. The control of Pi homeostasis has a significant biological importance, as it relates to numerous cellular mechanisms involved in energy metabolism, cell signaling, nucleic acid synthesis, membrane function, as well as skeletal health and integrity. Pi is essential for diverse biological processes, and negative Pi balance resulting from improperly regulated intestinal absorption, systemic utilization, and renal excretion. As results of these functions, chronic Pi deprivation causes several biological alterations, such as bone demineralization with unmineralized osateoid typical of osteomalacia in adults and rickets in developing animals and humans (1). Phosphatonins are new hormones playing an important role in the control of Pi homeostasis together with parathyroid hormone (PTH) and 1,25-dihydroxy vitamin D(3). Most insight into the underlying mechanisms was established by defining the molecular basis of different inherited disorders that are characterized by an abnormal regulation of Pi homeostasis.
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Affiliation(s)
- Laura Masi
- Department of Internal Medicine, Bone Metabolic Diseases Unit, University of Florence, Florence, Italy
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21
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22
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Mazzaferro S, Pasquali M, Pirrò G, Rotondi S, Tartaglione L. The bone and the kidney. Arch Biochem Biophys 2010; 503:95-102. [PMID: 20599669 DOI: 10.1016/j.abb.2010.06.028] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2010] [Revised: 06/24/2010] [Accepted: 06/26/2010] [Indexed: 12/21/2022]
Abstract
Renal tubular diseases may present with osteopenia, osteoporosis or osteomalacia, as a result of significant derangements in body electrolytes. In case of insufficient synthesis of calcitriol, as in renal failure, the more complex picture of renal osteodystrophy may develop. Hypothetically, also disturbed renal production of BMP-7 and Klotho could cause bone disease. However, the acknowledgment that osteocytes are capable of producing FGF23, a phosphaturic hormone at the same time modulating renal synthesis of calcitriol, indicates that it is also bone that can influence renal function. Importantly, a feed-back mechanism exists between FGF23 and calcitriol synthesis, while Klotho, produced by the kidney, determines activity and selectivity of FGF23. Identification of human diseases linked to disturbed production of FGF23 and Klotho underlines the importance of this new bone-kidney axis. Kidney and bone communicate reciprocally to regulate the sophisticated machinery responsible for divalent ions homeostasis and for osseous or extraosseous mineralisation processes.
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23
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Ichikawa S, Baujat G, Seyahi A, Garoufali AG, Imel EA, Padgett LR, Austin AM, Sorenson AH, Pejin Z, Topouchian V, Quartier P, Cormier-Daire V, Dechaux M, Malandrinou FC, Singhellakis PN, Le Merrer M, Econs MJ. Clinical variability of familial tumoral calcinosis caused by novel GALNT3 mutations. Am J Med Genet A 2010; 152A:896-903. [PMID: 20358599 PMCID: PMC3392654 DOI: 10.1002/ajmg.a.33337] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The GALNT3 gene encodes GalNAc-T3, which prevents degradation of the phosphaturic hormone, fibroblast growth factor 23 (FGF23). Biallelic mutations in either GALNT3 or FGF23 result in hyperphosphatemic familial tumoral calcinosis or its variant, hyperostosis-hyperphosphatemia syndrome. Tumoral calcinosis is characterized by the presence of ectopic calcifications around major joints, whereas hyperostosis-hyperphosphatemia syndrome is characterized by recurrent long bone lesions with hyperostosis. Here we investigated four patients with hyperphosphatemia and clinical manifestations including tumoral calcinosis and/or hyperostosis-hyperphosphatemia syndrome to determine underlying genetic cause and delineate phenotypic heterogeneity of these disorders. Mutational analysis of FGF23 and GALNT3 in these patients revealed novel homozygous mutations in GALNT3. Although the presence of massive calcifications, cortical hyperostosis, or dental anomalies was not shared by all patients, all had persistent hyperphosphatemia. Three of the patients also had inappropriately normal 1,25-dihyroxyvitamin D [1,25(OH)(2)D] and confirmed low circulating intact FGF23 concentrations. The four novel GALNT3 mutations invariably resulted in hyperphosphatemia as a result of low intact FGF23, but other clinical manifestations were variable. Therefore, tumoral calcinosis and hyperostosis-hyperphosphatemia syndrome represent a continuous spectrum of the same disease caused by increased phosphate levels, rather than two distinct disorders.
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Affiliation(s)
- Shoji Ichikawa
- Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA.
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Sprecher E. Familial tumoral calcinosis: from characterization of a rare phenotype to the pathogenesis of ectopic calcification. J Invest Dermatol 2010; 130:652-60. [PMID: 19865099 PMCID: PMC3169303 DOI: 10.1038/jid.2009.337] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Familial tumoral calcinosis (FTC) refers to a heterogeneous group of inherited disorders characterized by the occurrence of cutaneous and subcutaneous calcified masses. Two major forms of the disease are now recognized. Hyperphosphatemic FTC has been shown to result from mutations in three genes: fibroblast growth factor-23 (FGF23), coding for a potent phosphaturic protein, KL encoding Klotho, which serves as a co-receptor for FGF23, and GALNT3, which encodes a glycosyltransferase responsible for FGF23 O-glycosylation; defective function of any one of these three proteins results in hyperphosphatemia and ectopic calcification. The second form of the disease is characterized by absence of metabolic abnormalities, and is, therefore, termed normophosphatemic FTC. This variant was found to be associated with absence of functional SAMD9, a putative tumor suppressor and anti-inflammatory protein. The data gathered through the study of these rare disorders have recently led to the discovery of novel aspects of the pathogenesis of common disorders in humans, underscoring the potential concealed within the study of rare diseases.
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Affiliation(s)
- Eli Sprecher
- Department of Dermatology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel.
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25
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Fukumoto S. The role of bone in phosphate metabolism. Mol Cell Endocrinol 2009; 310:63-70. [PMID: 18822343 DOI: 10.1016/j.mce.2008.08.031] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2008] [Revised: 08/20/2008] [Accepted: 08/21/2008] [Indexed: 12/16/2022]
Abstract
Fibroblast growth factor 23 (FGF23) is a humoral factor that is produced by osteocytes and reduces serum phosphate and 1,25-dihydroxyvitamin D levels by acting on kidney through some FGF receptor and Klotho. Excessive action of FGF23 results in several hypophosphatemic diseases characterized by impaired renal tubular phosphate reabsorption. In contrast, deficient action of FGF23 causes familial hyperphosphatemic tumoral calcinosis with enhanced renal tubular phosphate reabsorption. In addition, FGF23 null mice also show hyperphosphatemia. The production and circulatory level of FGF23 seem to be tightly regulated while the detailed mechanism of this regulation remains to be clarified. These results indicate that FGF23 is a physiological factor working as a hormone produced by bone. The discovery of FGF23 has revealed the possibility that bone produces several humoral factors to communicate with other organs.
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Affiliation(s)
- Seiji Fukumoto
- Division of Nephrology & Endocrinology, Department of Medicine, University of Tokyo Hospital, Tokyo, Japan.
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26
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Chefetz I, Sprecher E. Familial tumoral calcinosis and the role of O-glycosylation in the maintenance of phosphate homeostasis. BIOCHIMICA ET BIOPHYSICA ACTA 2009; 1792:847-52. [PMID: 19013236 PMCID: PMC3169301 DOI: 10.1016/j.bbadis.2008.10.008] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2008] [Revised: 10/12/2008] [Accepted: 10/14/2008] [Indexed: 12/18/2022]
Abstract
Familial tumoral calcinosis refers to a group of disorders inherited in an autosomal recessive fashion. Hyperphosphatemic tumoral calcinosis is characterized by increased re-absorption of phosphate through the renal proximal tubule, resulting in elevated phosphate concentration and deposition of calcified deposits in cutaneous and subcutaneous tissues, as well as, occasionally, in visceral organs. The disease was found to result from mutations in at least 3 genes: GALNT3, encoding a glycosyltransferase termed ppGalNacT3, FGF23 encoding a potent phosphaturic protein, and KL encoding Klotho. Recent data showed that ppGalNacT3 mediates O-glycosylation of FGF23, thereby allowing for its secretion and possibly protecting it from proteolysis-mediated inactivation. Klotho was found to serve as a co-receptor for FGF23, thereby integrating the genetic data into a single physiological system. The elucidation of the molecular basis of HFTC shed new light upon the mechanisms regulating phosphate homeostasis, suggesting innovative therapeutic strategies for the management of hyperphosphatemia in common acquired conditions such as chronic renal failure.
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Affiliation(s)
- Ilana Chefetz
- Center for Translational Genetics, Rappaport Institute for Research in the Medical Sciences, Haifa, Israel
- Department of Dermatology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
| | - Eli Sprecher
- Center for Translational Genetics, Rappaport Institute for Research in the Medical Sciences, Haifa, Israel
- Faculty of Medicine, Technion- Israel Institute of Technology, Haifa, Israel
- Department of Dermatology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
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Ichikawa S, Sorenson AH, Austin AM, Mackenzie DS, Fritz TA, Moh A, Hui SL, Econs MJ. Ablation of the Galnt3 gene leads to low-circulating intact fibroblast growth factor 23 (Fgf23) concentrations and hyperphosphatemia despite increased Fgf23 expression. Endocrinology 2009; 150:2543-50. [PMID: 19213845 PMCID: PMC2689800 DOI: 10.1210/en.2008-0877] [Citation(s) in RCA: 120] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2008] [Accepted: 02/02/2009] [Indexed: 12/24/2022]
Abstract
Familial tumoral calcinosis is characterized by ectopic calcifications and hyperphosphatemia. The disease is caused by inactivating mutations in fibroblast growth factor 23 (FGF23), Klotho (KL), and uridine diphosphate-N-acetyl-alpha-D-galactosamine:polypeptide N-acetylgalactosaminyltransferase 3 (GALNT3). In vitro studies indicate that GALNT3 O-glycosylates a phosphaturic hormone, FGF23, and prevents its proteolytic processing, thereby allowing secretion of intact FGF23. In this study we generated mice lacking the Galnt3 gene, which developed hyperphosphatemia without apparent calcifications. In response to hyperphosphatemia, Galnt3-deficient mice had markedly increased Fgf23 expression in bone. However, compared with wild-type and heterozygous littermates, homozygous mice had only about half of circulating intact Fgf23 levels and higher levels of C-terminal Fgf23 fragments in bone. Galnt3-deficient mice also exhibited an inappropriately normal 1,25-dihydroxyvitamin D level and decreased alkaline phosphatase activity. Furthermore, renal expression of sodium-phosphate cotransporters and Kl were elevated in Galnt3-deficient mice. Interestingly, there were sex-specific phenotypes; only Galnt3-deficient males showed growth retardation, infertility, and significantly increased bone mineral density. In summary, ablation of Galnt3 impaired secretion of intact Fgf23, leading to decreased circulating Fgf23 and hyperphosphatemia, despite increased Fgf23 expression. Our findings indicate that Galnt3-deficient mice have a biochemical phenotype of tumoral calcinosis and provide in vivo evidence that Galnt3 plays an essential role in proper secretion of Fgf23 in mice.
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Affiliation(s)
- Shoji Ichikawa
- Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana 46202-5121, USA
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Gok F, Chefetz I, Indelman M, Kocaoglu M, Sprecher E. Newly discovered mutations in the GALNT3 gene causing autosomal recessive hyperostosis-hyperphosphatemia syndrome. Acta Orthop 2009; 80:131-4. [PMID: 19297793 PMCID: PMC2823226 DOI: 10.1080/17453670902807482] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2008] [Accepted: 09/05/2008] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND AND PURPOSE Periosteal new bone formation and cortical hyperostosis often suggest an initial diagnosis of bone malignancy or osteomyelitis. In the present study, we investigated the cause of persistent bone hyperostosis in the offspring of two consanguineous parents. METHODS Clinical assessment, imaging, and direct sequencing were used to elucidate the etiology of the condition seen in the patient. RESULTS Radiological examination revealed periosteal reaction, diaphysitis, and cortical hyperostosis, suggesting osteomyelitis or a bone neoplasm. The clinical and radiological features were also reminiscent of hyperostosis with hyperphosphatemia (HHS), a rare autosomal recessive disease manifesting with recurrent, transient, and painful swelling of the long bones. The identification of two novel heterozygous pathogenic mutations in the GALNT3 gene confirmed a diagnosis of HHS. INTERPRETATION Molecular analysis represents an invaluable tool in the differential diagnosis of persistent cortical hyperostosis.
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Affiliation(s)
- Faysal Gok
- Department of Pediatric Nephrology, Gulhane Military Medical School, Ankara, Turkey
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29
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Chefetz I, Kohno K, Izumi H, Uitto J, Richard G, Sprecher E. GALNT3, a gene associated with hyperphosphatemic familial tumoral calcinosis, is transcriptionally regulated by extracellular phosphate and modulates matrix metalloproteinase activity. BIOCHIMICA ET BIOPHYSICA ACTA 2009; 1792:61-7. [PMID: 18976705 PMCID: PMC3169302 DOI: 10.1016/j.bbadis.2008.09.016] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2008] [Revised: 09/29/2008] [Accepted: 09/29/2008] [Indexed: 12/16/2022]
Abstract
GALNT3 encodes UDP-N-acetyl-alpha-d-galactosamine: polypeptide N-acetylgalactosaminyl-transferarase 3 (ppGalNacT3), a glycosyltransferase which has been suggested to prevent proteolysis of FGF23, a potent phosphaturic protein. Accordingly, loss-of-function mutations in GALNT3 cause hyperphosphatemic familial tumoral calcinosis (HFTC), a rare autosomal recessive disorder manifesting with increased kidney reabsorption of phosphate, resulting in severe hyperphosphatemia and widespread ectopic calcifications. Although these findings definitely attribute a role to ppGalNacT3 in the regulation of phosphate homeostasis, little is currently known about the factors regulating GALNT3 expression. In addition, the effect of decreased GALNT3 expression in peripheral tissues has not been explored so far. In the present study, we demonstrate that GALNT3 expression is under the regulation of a number of factors known to be associated with phosphate homeostasis, including inorganic phosphate itself, calcium and 1,25-dihydroxyvitamin D(3). In addition, we show that decreased GALNT3 expression in human skin fibroblasts leads to increased expression of FGF7 and of matrix metalloproteinases, which have been previously implicated in the pathogenesis of ectopic calcification. Thus, the present data suggest that ppGalNacT3 may play a role in peripheral tissues of potential relevance to the pathogenesis of disorders of phosphate metabolism.
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Affiliation(s)
- Ilana Chefetz
- Laboratory of Molecular Dermatology and Department of Dermatology, Rambam Health Care Campus, Haifa, Israel
- Center for Translational Genetics, Rappaport Institute for Research in the Medical Sciences, Faculty of Medicine Haifa, Technion – Israel Institute of Technology, Haifa, Israel
| | - Kimitoshi Kohno
- Department of Molecular Biology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Hiroto Izumi
- Department of Molecular Biology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Jouni Uitto
- Department of Dermatology and Cutaneous Biology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Gabriele Richard
- Department of Dermatology and Cutaneous Biology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
- GeneDx, Gaithersburg, Maryland, USA
| | - Eli Sprecher
- Laboratory of Molecular Dermatology and Department of Dermatology, Rambam Health Care Campus, Haifa, Israel
- Center for Translational Genetics, Rappaport Institute for Research in the Medical Sciences, Faculty of Medicine Haifa, Technion – Israel Institute of Technology, Haifa, Israel
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30
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Nonfamilial hyperphosphatemic tumoral calcinosis with ulnar neuropathy. Joint Bone Spine 2008; 76:198-201. [PMID: 19073370 DOI: 10.1016/j.jbspin.2008.06.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2008] [Accepted: 06/05/2008] [Indexed: 01/26/2023]
Abstract
We present a case of multiple large juxta-articular painless masses involving both the elbows and right hip in a 27-year old south Asian male who presented with ulnar neuropathy and constitutional symptoms. Radiology, blood investigations and biopsy confirmed it to be hyperphosphatemic tumoral calcinosis. Patient was also diagnosed with an extremely rare association, testicular microlithiasis. Complete surgical excision with low phosphate diet resulted in complete neurological recovery and no recurrence at 30 months. Tumoral calcinosis should be considered in the differential diagnosis of a case with multiple, symptomatic juxta-articular masses.
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Garringer HJ, Malekpour M, Esteghamat F, Mortazavi SMJ, Davis SI, Farrow EG, Yu X, Arking DE, Dietz HC, White KE. Molecular genetic and biochemical analyses of FGF23 mutations in familial tumoral calcinosis. Am J Physiol Endocrinol Metab 2008; 295:E929-37. [PMID: 18682534 PMCID: PMC2575904 DOI: 10.1152/ajpendo.90456.2008] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2008] [Accepted: 08/03/2008] [Indexed: 11/22/2022]
Abstract
Fibroblast growth factor 23 (FGF23) is a hormone required for normal renal phosphate reabsorption. FGF23 gain-of-function mutations result in autosomal dominant hypophosphatemic rickets (ADHR), and FGF23 loss-of-function mutations cause familial hyperphosphatemic tumoral calcinosis (TC). In this study, we identified a novel recessive FGF23 TC mutation, a lysine (K) substitution for glutamine (Q) (160 C>A) at residue 54 (Q54K). To understand the molecular consequences of all known FGF23-TC mutants (H41Q, S71G, M96T, S129F, and Q54K), these proteins were stably expressed in vitro. Western analyses revealed minimal amounts of secreted intact protein for all mutants, and ELISA analyses demonstrated high levels of secreted COOH-terminal FGF23 fragments but low amounts of intact protein, consistent with TC patients' FGF23 serum profiles. Mutant protein function was tested and showed residual, yet decreased, bioactivity compared with wild-type protein. In examining the role of the FGF23 COOH-terminal tail (residues 180-251) in protein processing and activity, truncated mutants revealed that the majority of the residues downstream from the known FGF23 SPC protease site ((176)RXXR(179)/S(180)) were not required for protein secretion. However, residues adjacent to the RXXR site (between residues 188 and 202) were required for full bioactivity. In summary, we report a novel TC mutation and demonstrate a common defect of reduced FGF23 stability for all known FGF23-TC mutants. Finally, the majority of the COOH-terminal tail of FGF23 is not required for protein secretion but is required for full bioactivity.
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Affiliation(s)
- Holly J Garringer
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA
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32
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Thomas D, Vlachopapadopoulou E, Papadakis V, Sklavou R, Stefanaki K, Polychronopoulou S, Michalacos S. Testicular microlithiasis in siblings: clinical implications. Pediatr Radiol 2008; 38:688-90. [PMID: 18246339 DOI: 10.1007/s00247-008-0749-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2007] [Accepted: 12/16/2007] [Indexed: 12/18/2022]
Abstract
Testicular microlithiasis is a relatively uncommon condition in children. It is characterized by the presence of microcalcifications within the testicular parenchyma. Although it is a benign finding, underlying diseases and other conditions must be ruled out because testicular microlithiasis has been found in association with both benign and malignant lesions in the testes and other tissues. We present two brothers with testicular microlithiasis, and highlight the prevalence, natural history, associated malignant conditions and follow-up recommendations of children diagnosed with testicular microlithiasis.
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Affiliation(s)
- Dimitrios Thomas
- Department of Endocrinology, Metabolism and Diabetes, "Metaxa" Memorial Anticancer Research Hospital, Piraeus, Greece
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Ou SM, Lee SS, Tang SH, Wu ST, Wu CJ, Cha TL, Chang SY, Sun GH. Testicular microlithiasis in Taiwanese men. ACTA ACUST UNITED AC 2008; 53:339-44. [PMID: 18357963 DOI: 10.1080/01485010701730831] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Testicular microlithiasis (TM) is an unusual ultrasonographic manifestation in testicular parenchyma. Limited information is available about TM in Taiwanese men. We performed a retrospective analysis to investigate the characteristics of TM and its association with testicular cancer and infertility in Taiwan. Male patients who had received scrotal ultrasonography because of scrotal symptoms or infertility between January 2000 and December 2003 were recruited. The incidence of TM was 7.6%. Both testicular microlithiasis and testicular cancer occurred chiefly in the third decade. Patients with TM exhibit a higher chance of testicular cancer (6% vs. 0.9%). No local field effect between TM and testicular cancer was observed. Testicular microlithiasis severity is not positively correlated with sperm quality and sterility. Forty-eight patients (32%) were available at follow-up. No patient developed a testicular tumor or elevated tumor markers (AFP, beta-hCG) during follow-up. We suggest monthly self-examination, annual scrotal ultrasonography and tumor markers screening between the age of 20 and 30 years of patients with TM.
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Affiliation(s)
- Shih-Ming Ou
- Division of Urology, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, Republic of China
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34
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Ichikawa S, Imel EA, Kreiter ML, Yu X, Mackenzie DS, Sorenson AH, Goetz R, Mohammadi M, White KE, Econs MJ. A homozygous missense mutation in human KLOTHO causes severe tumoral calcinosis. J Clin Invest 2008; 117:2684-91. [PMID: 17710231 PMCID: PMC1940239 DOI: 10.1172/jci31330] [Citation(s) in RCA: 349] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2006] [Accepted: 05/25/2007] [Indexed: 01/12/2023] Open
Abstract
Familial tumoral calcinosis is characterized by ectopic calcifications and hyperphosphatemia due to inactivating mutations in FGF23 or UDP-N-acetyl-alpha-D-galactosamine:polypeptide N-acetylgalactosaminyltransferase 3 (GALNT3). Herein we report a homozygous missense mutation (H193R) in the KLOTHO (KL) gene of a 13-year-old girl who presented with severe tumoral calcinosis with dural and carotid artery calcifications. This patient exhibited defects in mineral ion homeostasis with marked hyperphosphatemia and hypercalcemia as well as elevated serum levels of parathyroid hormone and FGF23. Mapping of H193R mutation onto the crystal structure of myrosinase, a plant homolog of KL, revealed that this histidine residue was at the base of the deep catalytic cleft and mutation of this histidine to arginine should destabilize the putative glycosidase domain (KL1) of KL, thereby attenuating production of membrane-bound and secreted KL. Indeed, compared with wild-type KL, expression and secretion of H193R KL were markedly reduced in vitro, resulting in diminished ability of FGF23 to signal via its cognate FGF receptors. Taken together, our findings provide what we believe to be the first evidence that loss-of-function mutations in human KL impair FGF23 bioactivity, underscoring the essential role of KL in FGF23-mediated phosphate and vitamin D homeostasis in humans.
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Affiliation(s)
- Shoji Ichikawa
- Department of Medicine and
Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Division of Endocrinology, Children’s Memorial Hospital, Chicago, Illinois, USA.
Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.
Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Department of Pharmacology, New York University School of Medicine, New York, New York, USA
| | - Erik A. Imel
- Department of Medicine and
Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Division of Endocrinology, Children’s Memorial Hospital, Chicago, Illinois, USA.
Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.
Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Department of Pharmacology, New York University School of Medicine, New York, New York, USA
| | - Mary L. Kreiter
- Department of Medicine and
Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Division of Endocrinology, Children’s Memorial Hospital, Chicago, Illinois, USA.
Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.
Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Department of Pharmacology, New York University School of Medicine, New York, New York, USA
| | - Xijie Yu
- Department of Medicine and
Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Division of Endocrinology, Children’s Memorial Hospital, Chicago, Illinois, USA.
Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.
Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Department of Pharmacology, New York University School of Medicine, New York, New York, USA
| | - Donald S. Mackenzie
- Department of Medicine and
Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Division of Endocrinology, Children’s Memorial Hospital, Chicago, Illinois, USA.
Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.
Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Department of Pharmacology, New York University School of Medicine, New York, New York, USA
| | - Andrea H. Sorenson
- Department of Medicine and
Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Division of Endocrinology, Children’s Memorial Hospital, Chicago, Illinois, USA.
Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.
Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Department of Pharmacology, New York University School of Medicine, New York, New York, USA
| | - Regina Goetz
- Department of Medicine and
Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Division of Endocrinology, Children’s Memorial Hospital, Chicago, Illinois, USA.
Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.
Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Department of Pharmacology, New York University School of Medicine, New York, New York, USA
| | - Moosa Mohammadi
- Department of Medicine and
Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Division of Endocrinology, Children’s Memorial Hospital, Chicago, Illinois, USA.
Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.
Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Department of Pharmacology, New York University School of Medicine, New York, New York, USA
| | - Kenneth E. White
- Department of Medicine and
Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Division of Endocrinology, Children’s Memorial Hospital, Chicago, Illinois, USA.
Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.
Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Department of Pharmacology, New York University School of Medicine, New York, New York, USA
| | - Michael J. Econs
- Department of Medicine and
Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Division of Endocrinology, Children’s Memorial Hospital, Chicago, Illinois, USA.
Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.
Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Department of Pharmacology, New York University School of Medicine, New York, New York, USA
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Garringer HJ, Mortazavi SMJ, Esteghamat F, Malekpour M, Boztepe H, Tanakol R, Davis SI, White KE. Two novel GALNT3 mutations in familial tumoral calcinosis. Am J Med Genet A 2007; 143A:2390-6. [PMID: 17853462 DOI: 10.1002/ajmg.a.31947] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Familial tumoral calcinosis (TC) is characterized by elevated serum phosphate concentrations, normal or elevated 1,25(OH)2 vitamin D, as well as periarticular and vascular calcifications. Recessive mutations in the mucin-like glycosyltransferase GalNAc transferase-3 (GALNT3) and the phosphaturic hormone fibroblast growth factor-23 (FGF23) have been shown to result in TC. In the present study, mutational analyses were performed on two patients with TC to determine the molecular basis of their diseases. Analysis of the first patient revealed a novel, homozygous base insertion (1102_1103insT) in GALNT3 exon 5 that results in a frameshift and premature stop codon (E375X). The second patient had a novel homozygous transition (1460 g>a) in GALNT3 exon 7, which caused a nonsense mutation (W487X). Both mutations are predicted to markedly truncate the mature GALNT3 protein product. Although the patients carry GALNT3 mutations, these individuals presented with low-normal serum concentrations of intact biologically active FGF23 and high levels of C-terminal FGF23. In order to discern a possible relationship between GALNT3 and FGF23 in TC, a comprehensive assessment of the reported TC mutations was also performed. In summary, we have detected novel GALNT3 mutations that result in familial TC, and show that disturbed serum FGF23 concentrations are present in our TC cases as well as in previously reported cases. These studies expand our current genetic understanding of familial TC, and support a pathophysiological association between GALNT3 and FGF23.
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Affiliation(s)
- Holly J Garringer
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA, and Department of Orthopedics, Imam Khomeini University Hospital, Tehran, Iran
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36
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Rajpert-De Meyts E, Poll SN, Goukasian I, Jeanneau C, Herlihy AS, Bennett EP, Skakkebaek NE, Clausen H, Giwercman A, Mandel U. Changes in the profile of simple mucin-type O-glycans and polypeptide GalNAc-transferases in human testis and testicular neoplasms are associated with germ cell maturation and tumour differentiation. Virchows Arch 2007; 451:805-14. [PMID: 17694322 DOI: 10.1007/s00428-007-0478-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2007] [Revised: 07/11/2007] [Accepted: 07/13/2007] [Indexed: 12/16/2022]
Abstract
Testicular germ cell tumours (TGCT) exhibit remarkable ability to differentiate into virtually all somatic tissue types. In this study, we investigated changes in mucin-type O-glycosylation, which have been associated with somatic cell differentiation and cancer. Expression profile of simple mucin-type O-glycans (Tn, sialyl-Tn, T), histo-blood group H and A variants and six polypeptide GalNAc-transferases (T1-4, T6, T11) that control the site and density of O-glycosylation were analysed by immunohistochemistry during human testis development and in TGCT. Normal testis showed a restricted pattern; gonocytes expressed abundant sialyl-Tn and sialyl-T, and adult spermatogonia were devoid of any glycans, whereas spermatocytes and spermatids expressed exclusively glycans Tn and T and the GalNAc-T3 isoform. A subset of mature ejaculated spermatozoa expressed an additional glycan sialyl-T. The pattern found in testicular neoplasms recapitulated the developmental order: Pre-invasive carcinoma in situ (CIS) cells and seminoma expressed fetal type sialylated glycans in keeping with their gonocyte-like phenotype. Neither simple mucin-type O-glycans nor GalNAc-transferase isoforms were found in undifferentiated nonseminoma, i.e. embryonal carcinoma, whereas teratomas expressed them all to some extent but in a disorganized manner. We concluded that simple mucin-type O-glycans and their transferases are developmentally regulated in the human testis, with profound changes associated with neoplasia. The restricted O-glycosylation pattern in haploid germ cells suggests a role in their maturation or egg recognition/fertilization warranting further studies in male infertility, whereas the findings in TGCT provide new diagnostic tools and support our hypothesis that testicular cancer is a developmental disease of germ cell differentiation.
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MESH Headings
- Antigens, Tumor-Associated, Carbohydrate/genetics
- Antigens, Tumor-Associated, Carbohydrate/metabolism
- Antigens, Viral, Tumor/genetics
- Antigens, Viral, Tumor/metabolism
- Cell Differentiation/physiology
- Cell Transformation, Neoplastic/metabolism
- Cell Transformation, Neoplastic/pathology
- Gene Expression Profiling
- Gene Expression Regulation, Neoplastic
- Humans
- Male
- N-Acetylgalactosaminyltransferases/genetics
- N-Acetylgalactosaminyltransferases/metabolism
- Phenotype
- Spermatogenesis/physiology
- Spermatozoa/pathology
- Testicular Neoplasms/metabolism
- Testicular Neoplasms/pathology
- Testis/metabolism
- Testis/pathology
- Polypeptide N-acetylgalactosaminyltransferase
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Affiliation(s)
- E Rajpert-De Meyts
- University Department of Growth and Reproduction, Section GR-5064, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark.
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Abstract
Congenital disorders of glycosylation (CDG) are a large family of genetic diseases resulting from defects in the synthesis of glycans and in the attachment of glycans to other compounds. These disorders cause a wide range of human diseases, with examples emanating from all medical subspecialties. Since our 2001 review on CDG ( 36 ), this field has seen substantial growth: The number of N-glycosylation defects has doubled (from 6 to 12), five new O-glycosylation defects have been added to the two previously known ones, three combined N- and O-glycosylation defects have been identified, the first lipid glycosylation defects have been discovered, and a new domain, that of the hyperglycosylation defects, has been introduced. A number of CDG are due to defects in enzymes with a putative glycosyltransferase function. There is also a growing group of patients with unidentified defects (CDG-x), some with typical clinical presentations and others with presentations not seen before in CDG. This review focuses on the clinical, biochemical, and genetic characteristics of CDG and on advances expected in their future study and clinical management.
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Affiliation(s)
- Jaak Jaeken
- Department of Pediatrics, Center for Metabolic Disease, University of Leuven, Leuven, Belgium.
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38
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Sprecher E. Tumoral calcinosis: new insights for the rheumatologist into a familial crystal deposition disease. Curr Rheumatol Rep 2007; 9:237-42. [PMID: 17531178 DOI: 10.1007/s11926-007-0038-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
A growing body of evidence points to extraosseous calcification (calcification occurring in nonosseous tissues) as a major cause of morbidity and mortality in humans. The term familial tumoral calcinosis encompasses a number of rare recessive diseases, often associated with increased reabsorption of phosphate through the renal proximal tubule, which manifests with periarticular or acral calcium deposition. Recently, the molecular pathogenesis of this group of disorders has been elucidated, leading to the identification of several proteins playing pivotal roles in the regulation of extraosseous calcification. This report reviews these advances as well as the potential implications of these discoveries for the management of acquired conditions associated with abnormal calcification.
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Affiliation(s)
- Eli Sprecher
- Laboratory of Molecular Dermatology, Department of Dermatology, Rambam Health Care Campus, Faculty of Medicine and Rappaport Institute for Research in the Medical Sciences, Technion, Israel.
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Abstract
There is a discontinuum of hereditary and acquired disorders of phosphate homeostasis that are caused by either high or low circulating levels of the novel phosphaturic hormone fibroblastic growth factor 23 (FGF23). Disorders that are caused by high circulating levels of FGF23 are characterized by hypophosphatemia, decreased production of 1,25-dihydroxyvitamin D, and rickets/osteomalacia. On the other end of the spectrum are disorders that are caused by low circulating levels of FGF23, which are characterized by hyperphosphatemia, elevated production of 1,25-dihydroxyvitamin D, soft tissue calcifications, and hyperostosis. Knowledge of the genetic basis of these hereditary disorders of phosphate homeostasis and studies of their mouse homologues have uncovered a bone-kidney axis and new systems biology that govern bone mineralization, vitamin D metabolism, parathyroid gland function, and renal phosphate handling. Further understanding of this primary phosphate homeostatic pathway has the potential to have a significant impact on the diagnosis and treatment of disorders of bone and mineral metabolism.
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Affiliation(s)
- Shiguang Liu
- Kidney Institute, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66160, USA
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Barbieri AM, Filopanti M, Bua G, Beck-Peccoz P. Two novel nonsense mutations in GALNT3 gene are responsible for familial tumoral calcinosis. J Hum Genet 2007; 52:464-468. [PMID: 17351710 DOI: 10.1007/s10038-007-0126-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2006] [Accepted: 02/08/2007] [Indexed: 12/17/2022]
Abstract
Ectopic periarticular calcifications associated with elevated levels of serum phosphate represent the principal clinical features of hyperphosphatemic familial tumoral calcinosis (HFTC), a rare autosomal recessive metabolic disorder. The disease can be caused by recessive mutations in at least two different genes: GalNAc transferase 3 (GALNT3), encoding a glycosyltransferase that initiates mucin-type O-glycosylation, and fibroblast growth factor 23 (FGF23), which encodes a regulator of phosphate circulating levels. In the current study, we performed mutation analyses of the GALNT3 gene in a subject with HFTC and in his relatives. Sequence analyses revealed that the proband was a compound heterozygote for two novel nonsense mutations in exon 4 (Y322X) and in exon 7 (Q481X). Cosegregation of the mutations with the disease within the family was confirmed by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) analysis. This is the first report describing the simultaneous presence of two different stop codons in the coding sequence of the GALNT3 gene.
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Affiliation(s)
- Anna Maria Barbieri
- Department of Medical Sciences, Endocrine and Metabolic Unit, Pad. Granelli, University of Milan, Fondazione Policlinico IRCCS, Via Francesco Sforza 35, 20122, Milan, Italy.
| | - Marcello Filopanti
- Department of Medical Sciences, Endocrine and Metabolic Unit, Pad. Granelli, University of Milan, Fondazione Policlinico IRCCS, Via Francesco Sforza 35, 20122, Milan, Italy
| | - Guido Bua
- Servizio di Neurologia, Policlinico Sassarese, Sassari, Italy
| | - Paolo Beck-Peccoz
- Department of Medical Sciences, Endocrine and Metabolic Unit, Pad. Granelli, University of Milan, Fondazione Policlinico IRCCS, Via Francesco Sforza 35, 20122, Milan, Italy
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Kato K, Clausen H. Role of Polypeptide GalNAc-transferase T3 in Familial Tumoral Calcinosis: The Importance of a Single GalNAc-transferase Isoform. TRENDS GLYCOSCI GLYC 2007. [DOI: 10.4052/tigg.19.265] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Garringer HJ, Fisher C, Larsson TE, Davis SI, Koller DL, Cullen MJ, Draman MS, Conlon N, Jain A, Fedarko NS, Dasgupta B, White KE. The role of mutant UDP-N-acetyl-alpha-D-galactosamine-polypeptide N-acetylgalactosaminyltransferase 3 in regulating serum intact fibroblast growth factor 23 and matrix extracellular phosphoglycoprotein in heritable tumoral calcinosis. J Clin Endocrinol Metab 2006; 91:4037-42. [PMID: 16868048 DOI: 10.1210/jc.2006-0305] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
CONTEXT Familial tumoral calcinosis (TC) results from disruptions in phosphate metabolism and is characterized by high serum phosphate with normal or elevated 1,25 dihydroxyvitamin vitamin D concentrations and ectopic and vascular calcifications. Recessive loss-of-function mutations in UDP-N-acetyl-alpha-D-galactosamine-polypeptide N-acetylgalactosaminyltransferase 3 (GALNT3) and fibroblast growth factor-23 (FGF23) result in TC. OBJECTIVE The objective of the study was to determine the relationship between GALNT3 and FGF23 in familial TC. DESIGN, SETTING, AND PATIENTS We assessed the major biochemical defects and potential genes involved in patients with TC. INTERVENTION Combination therapy consisted of the phosphate binder Sevelamer and the carbonic anhydrase inhibitor acetazolamide. RESULTS We report a patient homozygous for a GALNT3 exon 1 deletion, which is predicted to truncate the encoded protein. This patient had high serum FGF23 concentrations when assessed with a C-terminal FGF23 ELISA but low-normal FGF23 levels when tested with an ELISA for intact FGF23 concentrations. Matrix extracellular phosphoglycoprotein has been identified as a possible regulator of phosphate homeostasis. Serum matrix extracellular phosphoglycoprotein levels, however, were normal in the family with GALNT3-TC and a kindred with TC carrying the FGF23 S71G mutation. The tumoral masses of the patient with GALNT3-TC completely resolved after combination therapy. CONCLUSIONS Our findings demonstrate that GALNT3 inactivation in patients with TC leads to inadequate production of biologically active FGF23 as the most likely cause of the hyperphosphatemic phenotype. Furthermore, combination therapy may be effective for reducing the tumoral burden associated with familial TC.
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Affiliation(s)
- Holly J Garringer
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, 975 West Walnut Street, IB130, Indianapolis, IN 46202, USA
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Topaz O, Indelman M, Chefetz I, Geiger D, Metzker A, Altschuler Y, Choder M, Bercovich D, Uitto J, Bergman R, Richard G, Sprecher E. A deleterious mutation in SAMD9 causes normophosphatemic familial tumoral calcinosis. Am J Hum Genet 2006; 79:759-64. [PMID: 16960814 PMCID: PMC1592555 DOI: 10.1086/508069] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2006] [Accepted: 07/28/2006] [Indexed: 11/03/2022] Open
Abstract
Familial tumoral calcinosis (FTC) is a rare autosomal recessive disorder characterized by the progressive deposition of calcified masses in cutaneous and subcutaneous tissues, which results in painful ulcerative lesions and severe skin and bone infections. Two major types of FTC have been recognized: hyperphosphatemic FTC (HFTC) and normophosphatemic FTC (NFTC). HFTC was recently shown to result from mutations in two different genes: GALNT3, which codes for a glycosyltransferase, and FGF23, which codes for a potent phosphaturic protein. To determine the molecular cause of NFTC, we performed homozygosity mapping in five affected families of Jewish Yemenite origin and mapped NFTC to 7q21-7q21.3. Mutation analysis revealed a homozygous mutation in the SAMD9 gene (K1495E), which was found to segregate with the disease in all families and to interfere with the protein expression. Our data suggest that SAMD9 is involved in the regulation of extraosseous calcification, a process of considerable importance in a wide range of diseases as common as atherosclerosis and autoimmune disorders.
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Affiliation(s)
- Orit Topaz
- Department of Dermatology and Laboratory of Molecular Dermatology, Rambam Health Care Campus, Haifa, Israel
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Kato K, Jeanneau C, Tarp MA, Benet-Pagès A, Lorenz-Depiereux B, Bennett EP, Mandel U, Strom TM, Clausen H. Polypeptide GalNAc-transferase T3 and familial tumoral calcinosis. Secretion of fibroblast growth factor 23 requires O-glycosylation. J Biol Chem 2006; 281:18370-7. [PMID: 16638743 DOI: 10.1074/jbc.m602469200] [Citation(s) in RCA: 305] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Mutations in the gene encoding the glycosyltransferase polypeptide GalNAc-T3, which is involved in initiation of O-glycosylation, were recently identified as a cause of the rare autosomal recessive metabolic disorder familial tumoral calcinosis (OMIM 211900). Familial tumoral calcinosis is associated with hyperphosphatemia and massive ectopic calcifications. Here, we demonstrate that the secretion of the phosphaturic factor fibroblast growth factor 23 (FGF23) requires O-glycosylation, and that GalNAc-T3 selectively directs O-glycosylation in a subtilisin-like proprotein convertase recognition sequence motif, which blocks processing of FGF23. The study suggests a novel posttranslational regulatory model of FGF23 involving competing O-glycosylation and protease processing to produce intact FGF23.
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Affiliation(s)
- Kentaro Kato
- Department of Medical Biochemistry and Genetics, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
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