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Magagnoli L, Cozzolino M, Galassi A. The open system of FGF-23 at the crossroad between additional P-lowering therapy, anemia and inflammation: how to deal with the intact and the C-terminal assays? Clin Kidney J 2023; 16:1543-1549. [PMID: 37779858 PMCID: PMC10539210 DOI: 10.1093/ckj/sfad144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Indexed: 10/03/2023] Open
Abstract
Fibroblast growth factor 23 (FGF-23) has been associated with increased cardiovascular risk and poor survival in dialysis patients. It is well established that FGF-23 synthesis is directly induced by positive phosphate (P) balance. On the other hand, P-lowering treatments such as nutritional P restriction, P binders and dialysis are capable of reducing FGF-23 levels. However, there are many uncertainties regarding the possibility of adopting FGF-23 to guide the clinical decision-making process in the context of chronic kidney disease-mineral bone disorder (CKD-MBD). Furthermore, the best assay to adopt for measurement of FGF-23 levels (namely the intact vs the C-terminal one) remains to be determined, especially in conditions capable of altering the synthesis as well as the cleavage of the intact and biologically active molecule, as occurs in the presence of CKD and its complications. This Editorial discusses the main insights provided by the post hoc analysis of the NOPHOS trial, with particular attention given to evidence-based peculiarities of the intact and the C-terminal assays available for measuring FGF-23 levels, especially in patients receiving additive P-lowering therapy in the presence of inflammation, anemia and iron deficiency.
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Affiliation(s)
- Lorenza Magagnoli
- University of Milan, Department of Health Sciences, Milano, Italy
- ASST Santi Paolo e Carlo, Renal Division, Milano, Italy
| | - Mario Cozzolino
- University of Milan, Department of Health Sciences, Milano, Italy
- ASST Santi Paolo e Carlo, Renal Division, Milano, Italy
| | - Andrea Galassi
- University of Milan, Department of Health Sciences, Milano, Italy
- ASST Santi Paolo e Carlo, Renal Division, Milano, Italy
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2
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Xie H, Bastepe I, Zhou W, Ay B, Ceraj Z, Portales-Castillo IA, Liu ES, Burnett-Bowie SAM, Jüppner H, Rhee EP, Bastepe M, Simic P. 1,25-Dihydroxyvitamin D3 regulates furin-mediated FGF23 cleavage. JCI Insight 2023; 8:e168957. [PMID: 37681408 PMCID: PMC10544208 DOI: 10.1172/jci.insight.168957] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 07/17/2023] [Indexed: 09/09/2023] Open
Abstract
Intact fibroblast growth factor 23 (iFGF23) is a phosphaturic hormone that is cleaved by furin into N-terminal and C-terminal fragments. Several studies have implicated vitamin D in regulating furin in infections. Thus, we investigated the effect of 1,25-dihydroxyvitamin D3 [1,25(OH)2D] and the vitamin D receptor (VDR) on furin-mediated iFGF23 cleavage. Mice lacking VDR (Vdr-/-) had a 25-fold increase in iFGF23 cleavage, with increased furin levels and activity compared with wild-type (WT) littermates. Inhibition of furin activity blocked the increase in iFGF23 cleavage in Vdr-/- animals and in a Vdr-knockdown osteocyte OCY454 cell line. Chromatin immunoprecipitation revealed VDR binding to DNA upstream of the Furin gene, with more transcription in the absence of VDR. In WT mice, furin inhibition reduced iFGF23 cleavage, increased iFGF23, and reduced serum phosphate levels. Similarly, 1,25(OH)2D reduced furin activity, decreased iFGF23 cleavage, and increased total FGF23. In a post hoc analysis of a randomized clinical trial, we found that ergocalciferol treatment, which increased serum 1,25(OH)2D, significantly decreased serum furin activity and iFGF23 cleavage, compared with placebo. Thus, 1,25(OH)2D inhibits iFGF23 cleavage via VDR-mediated suppression of Furin expression, thereby providing a mechanism by which vitamin D can augment phosphaturic iFGF23 levels.
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Affiliation(s)
- Han Xie
- Nephrology Division and
- Endocrine Division, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Isinsu Bastepe
- Nephrology Division and
- Endocrine Division, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Wen Zhou
- Nephrology Division and
- Endocrine Division, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Birol Ay
- Endocrine Division, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Zara Ceraj
- Nephrology Division and
- Endocrine Division, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Ignacio A. Portales-Castillo
- Nephrology Division and
- Endocrine Division, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Eva S. Liu
- Endocrine Division, Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | | | - Harald Jüppner
- Endocrine Division, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
- Pediatric Nephrology Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Eugene P. Rhee
- Nephrology Division and
- Endocrine Division, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Murat Bastepe
- Endocrine Division, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Petra Simic
- Nephrology Division and
- Endocrine Division, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
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3
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Frerker N, Karlsen TA, Stensland M, Nyman TA, Rayner S, Brinchmann JE. Comparison between articular chondrocytes and mesenchymal stromal cells for the production of articular cartilage implants. Front Bioeng Biotechnol 2023; 11:1116513. [PMID: 36896010 PMCID: PMC9989206 DOI: 10.3389/fbioe.2023.1116513] [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: 12/05/2022] [Accepted: 01/31/2023] [Indexed: 02/23/2023] Open
Abstract
Focal lesions of articular cartilage give rise to pain and reduced joint function and may, if left untreated, lead to osteoarthritis. Implantation of in vitro generated, scaffold-free autologous cartilage discs may represent the best treatment option. Here we compare articular chondrocytes (ACs) and bone marrow-derived mesenchymal stromal cells (MSCs) for their ability to make scaffold-free cartilage discs. Articular chondrocytes produced more extracellular matrix per seeded cell than mesenchymal stromal cells. Quantitative proteomics analysis showed that articular chondrocyte discs contained more articular cartilage proteins, while mesenchymal stromal cell discs had more proteins associated with cartilage hypertrophy and bone formation. Sequencing analysis revealed more microRNAs associated with normal cartilage in articular chondrocyte discs, and large-scale target predictions, performed for the first time for in vitro chondrogenesis, suggested that differential expression of microRNAs in the two disc types were important mechanisms behind differential synthesis of proteins. We conclude that articular chondrocytes should be preferred over mesenchymal stromal cells for tissue engineering of articular cartilage.
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Affiliation(s)
- Nadine Frerker
- Department of Immunology, Oslo University Hospital, Oslo, Norway
| | - Tommy A Karlsen
- Department of Immunology, Oslo University Hospital, Oslo, Norway
| | - Maria Stensland
- Department of Immunology, Oslo University Hospital, Oslo, Norway
| | - Tuula A Nyman
- Department of Immunology, Oslo University Hospital, Oslo, Norway.,Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Simon Rayner
- Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway.,Department of Medical Genetics, Oslo University Hospital, Oslo, Norway.,Hybrid Technology Hub-Centre of Excellence, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Jan E Brinchmann
- Department of Immunology, Oslo University Hospital, Oslo, Norway.,Department of Molecular Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
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4
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Guo L, Wang Y, Li S, Zhou L, Li D. GALNT3 protects against phosphate-induced calcification in vascular smooth muscle cells by enhancing active FGF23 and inhibiting the wnt/β-catenin signaling pathway. Cell Signal 2022; 100:110477. [PMID: 36162588 DOI: 10.1016/j.cellsig.2022.110477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Revised: 09/12/2022] [Accepted: 09/20/2022] [Indexed: 11/03/2022]
Abstract
Vascular calcification (VC) acts as a notable risk factor in the cardiovascular system. Disorder of phosphorus (Pi) metabolism promotes VC. Recent findings show that polypeptide N-acetylgalactosaminyltransferase 3(GALNT3) is Pi responsive and with potent effects on Pi homeostasis. However, whether GALNT3 is involved in high Pi-induced VC remains unclear. The present study investigated the potential role of GALNT3 as a novel regulator of VC. In vitro, human aortic smooth muscle cells (HASMCs) calcification was induced by inorganic Pi, while in vivo, C57BL/6 J mice were used to determine the effects of GALNT3 on Vitamin D3-induced medial arterial calcification. Alizarin red staining, Von Kossa staining, calcium and alkaline phosphatase (ALP) activity were performed to test VC. We showed that expression of GALNT3 was increased in the calcified HASMCs and aortas of the calcified mice.In vitro, overexpression of GALNT3 increased the levels of active full-length FGF23, accompanied by suppression of the osteoblast-related factors (Runx2 and BMP2), and further inhibited the formation of calcified nodules. Moreover, the protein levels of Wnt3a and active β-catenin were determined and it was found that GALNT3 significantly inhibited their expression. LiCl, a Wnt/β-catenin signaling activator, was observed to reverse the protective effect of GALNT3 overexpression. The opposite results were observed in the GALNT3 knockdown cells. In vivo, overexpression of GALNT3 by adeno-associated virus decreased the serum Pi and slowed the formation of aortic calcification in the calcified mice. In conclusion, our results indicate that GALNT3 counteracts high Pi-induced osteoblastic differentiation of VSMCs and protects against the initiation and progression of VC by inhibiting the Wnt/β-catenin signaling pathway.
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Affiliation(s)
- Liwei Guo
- School of Forensic Medicine, Xinxiang Medical University, Xinxiang, Henan, China; Xinxiang Key Laboratory of Metabolism and Integrative Physiology, Xinxiang, Henan, China.
| | - Yikai Wang
- School of Forensic Medicine, Xinxiang Medical University, Xinxiang, Henan, China; Xinxiang Key Laboratory of Metabolism and Integrative Physiology, Xinxiang, Henan, China
| | - Shijie Li
- School of Forensic Medicine, Xinxiang Medical University, Xinxiang, Henan, China; Xinxiang Key Laboratory of Metabolism and Integrative Physiology, Xinxiang, Henan, China
| | - Lulu Zhou
- School of Forensic Medicine, Xinxiang Medical University, Xinxiang, Henan, China; Xinxiang Key Laboratory of Metabolism and Integrative Physiology, Xinxiang, Henan, China
| | - Duan Li
- School of Basic Medicine, Xinxiang Medical University, Xinxiang, Henan, China.
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5
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Biruete A, Metzger CE, Chen NX, Swallow EA, Vrabec C, Clinkenbeard EL, Stacy AJ, Srinivasan S, O'Neill K, Avin KG, Allen MR, Moe SM. Effects of ferric citrate and intravenous iron sucrose on markers of mineral, bone, and iron homeostasis in a rat model of CKD-MBD. Nephrol Dial Transplant 2022; 37:1857-1867. [PMID: 35482713 PMCID: PMC9494145 DOI: 10.1093/ndt/gfac162] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Anemia and chronic kidney disease-mineral and bone disorder (CKD-MBD) are common and begin early in CKD. Limited studies have concurrently compared the effects of ferric citrate (FC) versus intravenous (IV) iron on CKD-MBD and iron homeostasis in moderate CKD. METHODS We tested the effects of 10 weeks of 2% FC versus IV iron sucrose in rats with moderate CKD (Cy/+ male rat) and untreated normal (NL) littermates. Outcomes included a comprehensive assessment of CKD-MBD, iron homeostasis and oxidative stress. RESULTS CKD rats had azotemia, elevated phosphorus, parathyroid hormone and fibroblast growth factor-23 (FGF23). Compared with untreated CKD rats, treatment with FC led to lower plasma phosphorus, intact FGF23 and a trend (P = 0.07) toward lower C-terminal FGF23. FC and IV iron equally reduced aorta and heart calcifications to levels similar to NL animals. Compared with NL animals, CKD animals had higher bone turnover, lower trabecular volume and no difference in mineralization; these were unaffected by either iron treatment. Rats treated with IV iron had cortical and bone mechanical properties similar to NL animals. FC increased the transferrin saturation rate compared with untreated CKD and NL rats. Neither iron treatment increased oxidative stress above that of untreated CKD. CONCLUSIONS Oral FC improved phosphorus homeostasis, some iron-related parameters and the production and cleavage of FGF23. The intermittent effect of low-dose IV iron sucrose on cardiovascular calcification and bone should be further explored in moderate-advanced CKD.
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Affiliation(s)
- Annabel Biruete
- Division of Nephrology, Indiana University School of Medicine, Indianapolis, IN, USA
- Department of Anatomy, Cell Biology, and Physiology, Indiana University School of Medicine, Indianapolis, IN, USA
- Department of Nutrition and Dietetics, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA
| | - Corinne E Metzger
- Department of Anatomy, Cell Biology, and Physiology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Neal X Chen
- Division of Nephrology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Elizabeth A Swallow
- Department of Anatomy, Cell Biology, and Physiology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Curtis Vrabec
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA
- College of Osteopathic Medicine, Marian University, Indianapolis, IN, USA
| | - Erica L Clinkenbeard
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Alexander J Stacy
- Department of Anatomy, Cell Biology, and Physiology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Shruthi Srinivasan
- Division of Nephrology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Kalisha O'Neill
- Division of Nephrology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Keith G Avin
- Division of Nephrology, Indiana University School of Medicine, Indianapolis, IN, USA
- Department of Physical Therapy, Indiana University School of Health and Human Sciences, Indiana University, Indianapolis, IN, USA
| | - Matthew R Allen
- Division of Nephrology, Indiana University School of Medicine, Indianapolis, IN, USA
- Department of Anatomy, Cell Biology, and Physiology, Indiana University School of Medicine, Indianapolis, IN, USA
- Roudebush Veterans Affairs Medical Center, Indianapolis, IN, IN, USA
| | - Sharon M Moe
- Division of Nephrology, Indiana University School of Medicine, Indianapolis, IN, USA
- Department of Anatomy, Cell Biology, and Physiology, Indiana University School of Medicine, Indianapolis, IN, USA
- Roudebush Veterans Affairs Medical Center, Indianapolis, IN, IN, USA
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6
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Dworkin LA, Clausen H, Joshi HJ. Applying transcriptomics to studyglycosylation at the cell type level. iScience 2022; 25:104419. [PMID: 35663018 PMCID: PMC9156939 DOI: 10.1016/j.isci.2022.104419] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 03/30/2022] [Accepted: 05/12/2022] [Indexed: 11/22/2022] Open
Abstract
The complex multi-step process of glycosylation occurs in a single cell, yet current analytics generally cannot measure the output (the glycome) of a single cell. Here, we addressed this discordance by investigating how single cell RNA-seq data can be used to characterize the state of the glycosylation machinery and metabolic network in a single cell. The metabolic network involves 214 glycosylation and modification enzymes outlined in our previously built atlas of cellular glycosylation pathways. We studied differential mRNA regulation of enzymes at the organ and single cell level, finding that most of the general protein and lipid oligosaccharide scaffolds are produced by enzymes exhibiting limited transcriptional regulation among cells. We predict key enzymes within different glycosylation pathways to be highly transcriptionally regulated as regulatable hotspots of the cellular glycome. We designed the Glycopacity software that enables investigators to extract and interpret glycosylation information from transcriptome data and define hotspots of regulation. RNA-seq can provide information on the glycosylation metabolic network state It is possible to readout glycosylation capacity from single cell RNA-seq data Genes regulating the biosynthesis of common glycan scaffolds show little regulation Key enzymes in the glycosylation network are predicted to be regulatable hotspots
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Affiliation(s)
- Leo Alexander Dworkin
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen N, Denmark
| | - Henrik Clausen
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen N, Denmark
| | - Hiren Jitendra Joshi
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen N, Denmark
- Corresponding author
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7
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Coelho H, Rivas MDL, Grosso AS, Diniz A, Soares CO, Francisco RA, Dias JS, Compañon I, Sun L, Narimatsu Y, Vakhrushev SY, Clausen H, Cabrita EJ, Jiménez-Barbero J, Corzana F, Hurtado-Guerrero R, Marcelo F. Atomic and Specificity Details of Mucin 1 O-Glycosylation Process by Multiple Polypeptide GalNAc-Transferase Isoforms Unveiled by NMR and Molecular Modeling. JACS AU 2022; 2:631-645. [PMID: 35373202 PMCID: PMC8969996 DOI: 10.1021/jacsau.1c00529] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Indexed: 05/10/2023]
Abstract
The large family of polypeptide GalNAc-transferases (GalNAc-Ts) controls with precision how GalNAc O-glycans are added in the tandem repeat regions of mucins (e.g., MUC1). However, the structural features behind the creation of well-defined and clustered patterns of O-glycans in mucins are poorly understood. In this context, herein, we disclose the full process of MUC1 O-glycosylation by GalNAc-T2/T3/T4 isoforms by NMR spectroscopy assisted by molecular modeling protocols. By using MUC1, with four tandem repeat domains as a substrate, we confirmed the glycosylation preferences of different GalNAc-Ts isoforms and highlighted the importance of the lectin domain in the glycosylation site selection after the addition of the first GalNAc residue. In a glycosylated substrate, with yet multiple acceptor sites, the lectin domain contributes to orientate acceptor sites to the catalytic domain. Our experiments suggest that during this process, neighboring tandem repeats are critical for further glycosylation of acceptor sites by GalNAc-T2/T4 in a lectin-assisted manner. Our studies also show local conformational changes in the peptide backbone during incorporation of GalNAc residues, which might explain GalNAc-T2/T3/T4 fine specificities toward the MUC1 substrate. Interestingly, we postulate that a specific salt-bridge and the inverse γ-turn conformation of the PDTRP sequence in MUC1 are the main structural motifs behind the GalNAc-T4 specificity toward this region. In addition, in-cell analysis shows that the GalNAc-T4 isoform is the only isoform glycosylating the Thr of the immunogenic epitope PDTRP in vivo, which highlights the relevance of GalNAc-T4 in the glycosylation of this epitope. Finally, the NMR methodology established herein can be extended to other glycosyltransferases, such as C1GalT1 and ST6GalNAc-I, to determine the specificity toward complex mucin acceptor substrates.
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Affiliation(s)
- Helena Coelho
- Associate
Laboratory i4HB—Institute for Health and Bioeconomy, NOVA School
of Science and Technology, Universidade
NOVA de Lisboa, 2829-516 Caparica, Portugal
- UCIBIO,
Department of Chemistry, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal
- CIC
bioGUNE, Basque Research and Technology
Alliance (BRTA), Bizkaia
Technology Park, Building 801A, 48170 Derio, Spain
- Department
of Organic Chemistry II, Faculty of Science & Technology, University of the Basque Country, Leioa 48940, Bizkaia, Spain
| | - Matilde de las Rivas
- Institute
for Biocomputation and Physics of Complex Systems (BIFI), Laboratorio
de Microscopias Avanzadas (LMA), University
of Zaragoza, Mariano
Esquillor s/n, Campus Rio Ebro, Edificio I+D, 50018 Zaragoza, Spain
| | - Ana S. Grosso
- Associate
Laboratory i4HB—Institute for Health and Bioeconomy, NOVA School
of Science and Technology, Universidade
NOVA de Lisboa, 2829-516 Caparica, Portugal
- UCIBIO,
Department of Chemistry, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal
| | - Ana Diniz
- Associate
Laboratory i4HB—Institute for Health and Bioeconomy, NOVA School
of Science and Technology, Universidade
NOVA de Lisboa, 2829-516 Caparica, Portugal
- UCIBIO,
Department of Chemistry, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal
| | - Cátia O. Soares
- Associate
Laboratory i4HB—Institute for Health and Bioeconomy, NOVA School
of Science and Technology, Universidade
NOVA de Lisboa, 2829-516 Caparica, Portugal
- UCIBIO,
Department of Chemistry, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal
| | - Rodrigo A. Francisco
- Associate
Laboratory i4HB—Institute for Health and Bioeconomy, NOVA School
of Science and Technology, Universidade
NOVA de Lisboa, 2829-516 Caparica, Portugal
- UCIBIO,
Department of Chemistry, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal
| | - Jorge S. Dias
- Associate
Laboratory i4HB—Institute for Health and Bioeconomy, NOVA School
of Science and Technology, Universidade
NOVA de Lisboa, 2829-516 Caparica, Portugal
- UCIBIO,
Department of Chemistry, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal
| | - Ismael Compañon
- Departamento
de Química, Centro de Investigación en Síntesis
Química, Universidad de La Rioja, E-26006 Logroño, Spain
| | - Lingbo Sun
- Copenhagen
Center for Glycomics, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen DK-2200, Denmark
| | - Yoshiki Narimatsu
- Copenhagen
Center for Glycomics, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen DK-2200, Denmark
| | - Sergey Y. Vakhrushev
- Copenhagen
Center for Glycomics, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen DK-2200, Denmark
| | - Henrik Clausen
- Copenhagen
Center for Glycomics, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen DK-2200, Denmark
| | - Eurico J. Cabrita
- Associate
Laboratory i4HB—Institute for Health and Bioeconomy, NOVA School
of Science and Technology, Universidade
NOVA de Lisboa, 2829-516 Caparica, Portugal
- UCIBIO,
Department of Chemistry, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal
| | - Jesús Jiménez-Barbero
- CIC
bioGUNE, Basque Research and Technology
Alliance (BRTA), Bizkaia
Technology Park, Building 801A, 48170 Derio, Spain
- Department
of Organic Chemistry II, Faculty of Science & Technology, University of the Basque Country, Leioa 48940, Bizkaia, Spain
- Ikerbasque,
Basque Foundation for Science, Maria Diaz de Haro 13, 48009 Bilbao, Spain
- Centro de Investigacion
Biomedica En Red de Enfermedades Respiratorias, 28029 Madrid, Spain
| | - Francisco Corzana
- Departamento
de Química, Centro de Investigación en Síntesis
Química, Universidad de La Rioja, E-26006 Logroño, Spain
| | - Ramon Hurtado-Guerrero
- Institute
for Biocomputation and Physics of Complex Systems (BIFI), Laboratorio
de Microscopias Avanzadas (LMA), University
of Zaragoza, Mariano
Esquillor s/n, Campus Rio Ebro, Edificio I+D, 50018 Zaragoza, Spain
- Copenhagen
Center for Glycomics, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen DK-2200, Denmark
- Fundación
ARAID, 50018 Zaragoza, Spain
| | - Filipa Marcelo
- Associate
Laboratory i4HB—Institute for Health and Bioeconomy, NOVA School
of Science and Technology, Universidade
NOVA de Lisboa, 2829-516 Caparica, Portugal
- UCIBIO,
Department of Chemistry, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal
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8
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Polypeptide-GalNAc-Transferase-13 Shows Prognostic Impact in Breast Cancer. Cancers (Basel) 2021; 13:cancers13225616. [PMID: 34830771 PMCID: PMC8616257 DOI: 10.3390/cancers13225616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 11/02/2021] [Accepted: 11/04/2021] [Indexed: 11/17/2022] Open
Abstract
Breast cancer is a public health concern and is currently the fifth cause of mortality worldwide. Identification of different biological subtypes is essential for clinical management; therefore, the role of pathologists is essential and useful tools for immunohistochemistry diagnosis are needed. Polypeptide-GalNAc-transferases are emerging novel biomarkers related to cancer behavior and GalNAc-T13, correlated with aggressiveness in some tumors, is an interesting candidate. Few monoclonal antibodies reacting with native proteins, and not affected by fixation and paraffin embedding, have been reported. The aim of this work was to develop a useful monoclonal antibody anti-GalNAc-T13 and to assess its potential significance in breast cancer diagnosis. We evaluated 6 human breast cancer cell lines, 338 primary breast tumors and 48 metastatic lymph nodes and looked for clinical significance correlating GalNAc-T13 expression with patients' clinical features and survival. We found high GalNAc-T13 expression in 43.8% of the cases and observed a significant higher expression in metastatic lymph nodes, correlating with worse overall survival. We hypothesized several possible molecular mechanisms and their implications. We conclude that GalNAc-T13 may be a novel biomarker in breast cancer, useful for routine pathological diagnosis. Elucidation of molecular mechanisms related to aggressiveness should contribute to understand the role of GalNAc-T13 in breast cancer biology.
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9
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Ratsma DMA, Zillikens MC, van der Eerden BCJ. Upstream Regulators of Fibroblast Growth Factor 23. Front Endocrinol (Lausanne) 2021; 12:588096. [PMID: 33716961 PMCID: PMC7952762 DOI: 10.3389/fendo.2021.588096] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 01/11/2021] [Indexed: 12/11/2022] Open
Abstract
Fibroblast growth factor 23 (FGF23) has been described as an important regulator of mineral homeostasis, but has lately also been linked to iron deficiency, inflammation, and erythropoiesis. FGF23 is essential for the maintenance of phosphate homeostasis in the body and activating mutations in the gene itself or inactivating mutations in its upstream regulators can result in severe chronic hypophosphatemia, where an unbalanced mineral homeostasis often leads to rickets in children and osteomalacia in adults. FGF23 can be regulated by changes in transcriptional activity or by changes at the post-translational level. The balance between O-glycosylation and phosphorylation is an important determinant of how much active intact or inactive cleaved FGF23 will be released in the circulation. In the past years, it has become evident that iron deficiency and inflammation regulate FGF23 in a way that is not associated with its classical role in mineral metabolism. These conditions will not only result in an upregulation of FGF23 transcription, but also in increased cleavage, leaving the levels of active intact FGF23 unchanged. The exact mechanisms behind and function of this process are still unclear. However, a deeper understanding of FGF23 regulation in both the classical and non-classical way is important to develop better treatment options for diseases associated with disturbed FGF23 biology. In this review, we describe how the currently known upstream regulators of FGF23 change FGF23 transcription and affect its post-translational modifications at the molecular level.
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10
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Kawabata C, Komaba H, Ishida H, Nakagawa Y, Hamano N, Koizumi M, Kanai G, Wada T, Nakamura M, Fukagawa M. Changes in Fibroblast Growth Factor 23 and Soluble Klotho Levels After Hemodialysis Initiation. Kidney Med 2019; 2:59-67. [PMID: 33015612 PMCID: PMC7525799 DOI: 10.1016/j.xkme.2019.09.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Rationale & Objective Patients with chronic kidney failure have markedly elevated fibroblast growth factor 23 (FGF-23) levels and decreased soluble Klotho levels. However, no studies have examined the effects of hemodialysis initiation on the levels of these hormones and other parameters of mineral metabolism. Study Design Prospective single-arm study. Setting & Participants 20 individuals with incident kidney failure initiating hemodialysis. Exposure Initiation of hemodialysis. Dose adjustments of phosphate binders and vitamin D receptor activators and use of calcimimetics, erythropoiesis-stimulating agents, and intravenous iron were prohibited. Outcomes Changes in serum levels of FGF-23, soluble Klotho, and other biochemical parameters of mineral metabolism, measured before and after each hemodialysis session, for a total of 4 sessions over 5 days. Analytical Approach Repeated-measures analysis of variance. Results At baseline, participants had 18-fold higher median FGF-23 levels and 1.6-fold lower mean soluble Klotho levels compared with age- and sex-matched healthy individuals. Initiation of hemodialysis led to progressive reductions in serum phosphorus, intact parathyroid hormone, and FGF-23 levels, with dialysis-related fluctuations. No reductions were observed in levels of α1-microglobulin, which has molecular weight comparable to FGF-23. The magnitude of the FGF-23 level reductions was strongly associated with concomitant changes in serum phosphorus levels but not with the changes in intact parathyroid hormone levels. Soluble Klotho levels did not change after the initiation of hemodialysis. Limitations Single-arm design, small sample size, short follow-up period. Conclusions Initiation of hemodialysis in patients with chronic kidney failure led to progressive reductions in FGF-23 levels in association with reductions in serum phosphorus levels. These results suggest that phosphorus is a strong inducer of FGF-23 production and that regulation of FGF-23 production is a rapid process.
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Affiliation(s)
- Chiaki Kawabata
- Division of Nephrology, Endocrinology and Metabolism, Tokai University School of Medicine, Isehara, Japan
| | - Hirotaka Komaba
- Division of Nephrology, Endocrinology and Metabolism, Tokai University School of Medicine, Isehara, Japan.,The Institute of Medical Sciences, Tokai University, Isehara, Japan
| | - Hiroaki Ishida
- Department of Transplant Surgery, Tokai University School of Medicine, Isehara, Japan
| | - Yosuke Nakagawa
- Division of Nephrology, Endocrinology and Metabolism, Tokai University School of Medicine, Isehara, Japan
| | - Naoto Hamano
- Division of Nephrology, Endocrinology and Metabolism, Tokai University School of Medicine, Isehara, Japan
| | - Masahiro Koizumi
- Division of Nephrology, Endocrinology and Metabolism, Tokai University School of Medicine, Isehara, Japan
| | - Genta Kanai
- Division of Nephrology, Endocrinology and Metabolism, Tokai University School of Medicine, Isehara, Japan
| | - Takehiko Wada
- Division of Nephrology, Endocrinology and Metabolism, Tokai University School of Medicine, Isehara, Japan
| | - Michio Nakamura
- Department of Transplant Surgery, Tokai University School of Medicine, Isehara, Japan
| | - Masafumi Fukagawa
- Division of Nephrology, Endocrinology and Metabolism, Tokai University School of Medicine, Isehara, Japan
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Joshi HJ, Hansen L, Narimatsu Y, Freeze HH, Henrissat B, Bennett E, Wandall HH, Clausen H, Schjoldager KT. Glycosyltransferase genes that cause monogenic congenital disorders of glycosylation are distinct from glycosyltransferase genes associated with complex diseases. Glycobiology 2018; 28:284-294. [PMID: 29579191 DOI: 10.1093/glycob/cwy015] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Indexed: 12/12/2022] Open
Abstract
Glycosylation of proteins, lipids and proteoglycans in human cells involves at least 167 identified glycosyltransferases (GTfs), and these orchestrate the biosynthesis of diverse types of glycoconjugates and glycan structures. Mutations in this part of the genome-the GTf-genome-cause more than 58 rare, monogenic congenital disorders of glycosylation (CDGs). They are also statistically associated with a large number of complex phenotypes, diseases or predispositions to complex diseases based on Genome-Wide Association Studies (GWAS). CDGs are extremely rare and often with severe medical consequences. In contrast, GWAS are likely to identify more common genetic variations and generally involve less severe and distinct traits. We recently confirmed that structural defects in GTf genes are extremely rare, which seemed at odds with the large number of GWAS pointing to GTf-genes. To resolve this issue, we surveyed the GTf-genome for reported CDGs and GWAS candidates; we found little overlap between the two groups of genes. Moreover, GTf-genes implicated by CDG or GWAS appear to constitute different classes with respect to their: (i) predicted roles in glycosylation pathways; (ii) potential for partial redundancy by closely homologous genes; and (iii) transcriptional regulation as evaluated by RNAseq data. Our analysis suggest that more complex traits are caused by dysregulation rather than structural deficiency of GTfs, which suggests that some glycosylation reactions may be predicted to be under tight regulation for fine-tuning of important biological functions.
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Affiliation(s)
- Hiren J Joshi
- Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine and School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Lars Hansen
- Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine and School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Yoshiki Narimatsu
- Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine and School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Hudson H Freeze
- Human Genetics Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Bernard Henrissat
- Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine and School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark.,Architecture et Fonction des Macromolécules Biologiques, Centre National de la Recherche Scientifique (CNRS), Aix-Marseille University, F-13288 Marseille, France
| | - Eric Bennett
- Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine and School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Hans H Wandall
- Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine and School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Henrik Clausen
- Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine and School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Katrine T Schjoldager
- Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine and School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
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12
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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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13
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Liu Y, Chen T, Xing J. Effect of rosuvastatin on the expression of candidate gene GALNT3 in atherosclerosis. Exp Ther Med 2018; 15:4880-4884. [PMID: 29805509 PMCID: PMC5952099 DOI: 10.3892/etm.2018.6008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 02/01/2018] [Indexed: 11/05/2022] Open
Abstract
The effect of rosuvastatin on the expression of candidate gene polypeptide N-acetylgalactosaminyltrans ferase 3 (GALNT3) in atherosclerosis was studied. Sixty Wistar rats were randomly divided into the control (n=20), model (atherosclerosis group, n=20) and administration (rosuvastatin group, n=20) groups. The atherosclerosis model was established via injecting D3.6 million units of vitamin per kilogram of body weight and then the rats were fed with high-fat diet for 6 weeks. The total cholesterol, serum triglyceride and nitric oxide contents were detected using the kits, the morphological changes in thoracic aorta were observed via hematoxylin and eosin (H&E) staining, the mRNA expression of candidate gene GALNT3 was detected via reverse transcription-polymerase chain reaction (RT-PCR), and the protein expression of candidate gene GALNT3 was detected via western blot analysis. Compared with those in the control group, the contents of serum triglyceride and total cholesterol in the model group were significantly increased, and then significantly decreased after drug administration. Morphological observation showed that the surface of thoracic aorta was not smooth with endothelial shedding, and the smooth muscle cells were arranged irregularly and their number was obviously increased. Moreover, RT-PCR and western blot analysis revealed that the mRNA and protein expressions of GALNT3 were significantly increased in the administration group. Rosuvastatin can therefore significantly upregulate the expression of candidate gene GALNT3 in atherosclerosis, thereby reducing the incidence of atherosclerosis.
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Affiliation(s)
- Yanshao Liu
- Department of Cardiovascular Medicine, Jinan Zhangqiu District Hospital of Traditional Chinese Medicine, Jinan, Shandong 250200, P.R. China
| | - Tao Chen
- Department of Cardiovascular Medicine, Jinan Zhangqiu District Hospital of Traditional Chinese Medicine, Jinan, Shandong 250200, P.R. China
| | - Jieyong Xing
- Department of Cardiovascular Medicine, Jinan Zhangqiu District Hospital of Traditional Chinese Medicine, Jinan, Shandong 250200, P.R. China
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14
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Fine-Tuning Limited Proteolysis: A Major Role for Regulated Site-Specific O-Glycosylation. Trends Biochem Sci 2018; 43:269-284. [PMID: 29506880 DOI: 10.1016/j.tibs.2018.02.005] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 01/26/2018] [Accepted: 02/02/2018] [Indexed: 11/23/2022]
Abstract
Limited proteolytic processing is an essential and ubiquitous post-translational modification (PTM) affecting secreted proteins; failure to regulate the process is often associated with disease. Glycosylation is also a ubiquitous protein PTM and site-specific O-glycosylation in close proximity to sites of proteolysis can regulate and direct the activity of proprotein convertases, a disintegrin and metalloproteinases (ADAMs), and metalloproteinases affecting the activation or inactivation of many classes of proteins, including G-protein-coupled receptors (GPCRs). Here, we summarize the emerging data that suggest O-glycosylation to be a key regulator of limited proteolysis, and highlight the potential for crosstalk between multiple PTMs.
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15
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Guo L, Li D, Li M, Li L, Huang Y. Variant in GALNT3 Gene Linked with Reduced Coronary Artery Disease Risk in Chinese Population. DNA Cell Biol 2017; 36:529-534. [PMID: 28453302 DOI: 10.1089/dna.2017.3688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Our previous study found expression of GALNT3 gene was reduced in coronary artery disease (CAD) patients, and it contributed to endothelial injury by regulating apoptosis and matrix metalloproteinase (MMP) expression. GALNT3 gene may be a potential target for future therapeutic intervention of CAD. However, none reports linking the GALNT3 gene to susceptibility of CAD. This study investigated the variant associations of GALNT3 gene and CAD. Thirteen single nucleotide polymorphism (SNP) in and around the GALNT3 gene were tagged and analyzed in CAD patients (n = 1515) and control individuals (n = 5019), and the SNPs with CAD were tested with multiple logistic regression analysis in an additive genetic model (with one degree of freedom) after adjusting for age and sex. Expression of GALNT3 gene was detected by real-time PCR and Western blot. Luciferase reporter assays were used to detect the allele-specific effect of rs4621175 on transcriptional activity. Two GALNT3 markers, rs13427924 and rs4621175, were significantly associated with CAD (odds ratio [OR] = 0.87, p = 1.01 × 10-3 and OR = 0.75, p = 2.51 × 10-4, respectively), and the risk A allele of rs4621175 was associated with lower GALNT3 expression in both mRNA and protein level; also, A allele showed decreased reporter activity. In addition, we found the level of GALNT3 negatively correlated with MMP-2 gene expression. This study identified GALNT3 as a novel gene that rendered patients susceptible to CAD, and the A allele of a disease-associated variant rs4621175 linked reduced CAD risk through decreased GALNT3 expression. These results confirmed the role of GALNT3 gene in CAD and provided new insights into the genetic regulation of the GALNT3 gene with respect to the pathogenesis of CAD.
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Affiliation(s)
- Liwei Guo
- 1 Department of Forensic Medicine, Xinxiang Medical University , Xinxiang, China
| | - Duan Li
- 2 Department of Basic Medicine, Xinxiang Medical University , Xinxiang, China
| | - Mengting Li
- 3 State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College , Beijing, China
| | - Lin Li
- 3 State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College , Beijing, China
| | - Yanmei Huang
- 1 Department of Forensic Medicine, Xinxiang Medical University , Xinxiang, China
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16
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Guo L, Wang L, Li H, Yang X, Yang B, Li M, Huang J, Gu D. Down regulation of GALNT3 contributes to endothelial cell injury via activation of p38 MAPK signaling pathway. Atherosclerosis 2016; 245:94-100. [PMID: 26714046 DOI: 10.1016/j.atherosclerosis.2015.12.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 12/08/2015] [Accepted: 12/14/2015] [Indexed: 12/11/2022]
Abstract
OBJECTIVE The GALNT3 gene encodes polypeptide N-acetylgalactosaminyl transferase 3 (GalNAc-T3), a member of the GalNAc-Ts family that transfers the N-acetylgalactosamine to the hydroxyl group of serine and threonine residue in the first step of O-linked oligosaccharide biosynthesis. Emerging evidences have linked GalNAc-Ts family to coronary artery disease (CAD). However the effect of GALNT3 in CAD is unknown. The present study investigated the function and mechanisms of GALNT3 gene in endothelial injury. METHODS AND RESULTS The GALNT3 mRNA level was decreased by 48.2% in CAD patients (n = 58), compared with that of controls (n = 120). Expression of GALNT3 was also decreased in human umbilical vein endothelial cells (HUVECs) treated with CAD sera and subjected to hypoxia in vitro. Knockdown of GALNT3 promoted apoptosis and up-regulated the expression of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-14 (MMP-14). Conversely, overexpression of GALNT3 significantly inhibited HUVECs apoptosis and down-regulated the expression of MMP-2 and MMP-14 genes, in addition, overexpression of GALNT3 attenuated hypoxia-induced apoptosis and expression of MMP-2 and MMP-14. Finally, the ratio of cytosolic p-p38 MAPK/p38 MAPK expression was significantly increased with GALNT3 knockdown and lower with GALNT3 overexpression, while the p38 MAPK inhibitor SB203580 blocked the effects of GALNT3 knockdown. CONCLUSIONS Expression of GALNT3 was reduced in CAD patients, and down regulation of GALNT3 contributed to endothelial injury by promoting apoptosis and up-regulating the expression of MMP-2 and MMP-14 genes via p38 MAPK activation. GALNT3 may be a potential target for future therapeutic intervention for CAD.
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Affiliation(s)
- Liwei Guo
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Laiyuan Wang
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
| | - Hongfan Li
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Xueli Yang
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Bin Yang
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Mengting Li
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Jianfeng Huang
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Dongfeng Gu
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
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17
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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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18
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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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19
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Rymen D, Jaeken J. Skin manifestations in CDG. J Inherit Metab Dis 2014; 37:699-708. [PMID: 24554337 DOI: 10.1007/s10545-014-9678-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 12/01/2013] [Accepted: 01/20/2014] [Indexed: 10/25/2022]
Abstract
The group of congenital disorders of glycosylation (CDG) has expanded tremendously since its first description in 1980, with around 70 distinct disorders described to date. A great phenotypic variability exists, ranging from multisystem disease to single organ involvement. Skin manifestations, although inconsistently present, are part of this broad clinical spectrum. Indeed, the presence of inverted nipples, fat pads and orange peel skin in a patient with developmental delay are considered as a hallmark of CDG, particularly seen in PMM2 deficiency. However, over the years many more dermatological findings have been observed (e.g., ichthyosis, cutis laxa, tumoral calcinosis…). In this review we will discuss the variety of skin manifestations reported in CDG. Moreover, we will explore the possible mechanisms that link a certain glycosylation deficiency to its skin phenotype.
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Affiliation(s)
- D Rymen
- Center for Human Genetics, University of Leuven, Leuven, Belgium,
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20
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Kido S, Fujihara M, Nomura K, Sasaki S, Mukai R, Ohnishi R, Kaneko I, Segawa H, Tatsumi S, Izumi H, Kohno K, Miyamoto KI. Molecular mechanisms of cadmium-induced fibroblast growth factor 23 upregulation in osteoblast-like cells. Toxicol Sci 2014; 139:301-16. [PMID: 24614234 DOI: 10.1093/toxsci/kfu043] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023] Open
Abstract
Itai-itai disease is thought to be the result of chronic cadmium (Cd) intoxication. Renal proximal tubules are a major target of Cd toxicity. The whole mechanism of the adverse effects of Cd remains unresolved, especially how renal damage is related to the development of bone lesions. Fibroblast growth factor 23 (FGF23) is a bone-derived phosphaturic factor that regulates vitamin D and inorganic phosphate metabolism in the kidney. To clarify the role of FGF23 on Cd toxicity, we investigated the mechanisms of Cd-induced FGF23 production in the bone. Cd injection into mice significantly increased plasma FGF23 concentrations, but did not change FGF23 mRNA expression in bone. GalNAc-T3 is involved in secreting intact FGF23. To determine potential roles of GalNAc-T3 in Cd-induced FGF23 production, we examined the effect of Cd on GalNAc-T3 mRNA expression in vivo and in vitro. GalNAc-T3 gene expression was significantly increased in the bones of Cd-injected mice. Cd also enhanced the expression of GalNAc-T3 in cultured osteosarcoma UMR106 cells and primary osteocytes. Cd activated aryl hydrocarbon receptors (AhR) and AhR were required for GalNAc-T3 gene expression induced by Cd. In addition, Cd-dependent FGF23 production was completely inhibited by an AhR antagonist. AhR siRNA markedly suppressed the stimulation of transcriptional activity by Cd. Furthermore, Cd induced AhR activation via phosphorylation of Ser-68 by p38 kinase in the nuclear export signal of AhR. Thus, Cd stimulated GalNAc-T3 gene transcription via enhanced AhR binding to the GalNAc-T3 promoter. These findings suggest that the Cd-induced increase in GalNAc-T3 suppresses proteolytic processing of FGF23 and increases serum FGF23 concentrations.
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Affiliation(s)
- Shinsuke Kido
- Department of Molecular Nutrition, Institute of Health Biosciences, the University of Tokushima Graduate School, Tokushima 770-8503, Japan
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Tagliabracci VS, Engel JL, Wiley SE, Xiao J, Gonzalez DJ, Nidumanda Appaiah H, Koller A, Nizet V, White KE, Dixon JE. Dynamic regulation of FGF23 by Fam20C phosphorylation, GalNAc-T3 glycosylation, and furin proteolysis. Proc Natl Acad Sci U S A 2014; 111:5520-5. [PMID: 24706917 PMCID: PMC3992636 DOI: 10.1073/pnas.1402218111] [Citation(s) in RCA: 223] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The family with sequence similarity 20, member C (Fam20C) has recently been identified as the Golgi casein kinase. Fam20C phosphorylates secreted proteins on Ser-x-Glu/pSer motifs and loss-of-function mutations in the kinase cause Raine syndrome, an often-fatal osteosclerotic bone dysplasia. Fam20C is potentially an upstream regulator of the phosphate-regulating hormone fibroblast growth factor 23 (FGF23), because humans with FAM20C mutations and Fam20C KO mice develop hypophosphatemia due to an increase in full-length, biologically active FGF23. However, the mechanism by which Fam20C regulates FGF23 is unknown. Here we show that Fam20C directly phosphorylates FGF23 on Ser(180), within the FGF23 R(176)XXR(179)/S(180)AE subtilisin-like proprotein convertase motif. This phosphorylation event inhibits O-glycosylation of FGF23 by polypeptide N-acetylgalactosaminyltransferase 3 (GalNAc-T3), and promotes FGF23 cleavage and inactivation by the subtilisin-like proprotein convertase furin. Collectively, our results provide a molecular mechanism by which FGF23 is dynamically regulated by phosphorylation, glycosylation, and proteolysis. Furthermore, our findings suggest that cross-talk between phosphorylation and O-glycosylation of proteins in the secretory pathway may be an important mechanism by which secreted proteins are regulated.
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Affiliation(s)
| | | | | | | | | | - Hitesh Nidumanda Appaiah
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202; and
| | - Antonius Koller
- Stony Brook University Proteomics Center, School of Medicine, Stony Brook University, Stony Brook, NY 11794
| | - Victor Nizet
- Pediatrics
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093
| | - Kenneth E. White
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202; and
| | - Jack E. Dixon
- Departments of Pharmacology
- Cellular and Molecular Medicine, and
- Chemistry and Biochemistry and
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Deng XG, Qiu RL, Wu YH, Li ZX, Xie P, Zhang J, Zhou JJ, Zeng LX, Tang J, Maharjan A, Deng JM. Overexpression of miR-122 promotes the hepatic differentiation and maturation of mouse ESCs through a miR-122/FoxA1/HNF4a-positive feedback loop. Liver Int 2014; 34:281-95. [PMID: 23834235 DOI: 10.1111/liv.12239] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Accepted: 05/11/2013] [Indexed: 12/13/2022]
Abstract
BACKGROUND & AIMS microRNA-122 is the only identified liver-specific miRNA and plays a crucial role in liver development, maintenance of hepatic homeostasis as well as tumourigenesis. In our previous differentiation of ESCs into hepatocytes, microRNA-122 (miR-122) was expressed at a relatively low level. Here, we aim to elucidate the effect and underlying mechanisms of miR-122 during differentiation of ESCs into hepatocytes. METHODS Mouse ESCs were initially induced towards HPCs by activin A, FGF-4 and sodium butyrate and were subsequently transfected with a recombinant adenovirus expressing vector pAV.Ex1d-CMV>miR-122/IRES/eGFP 9 days after induction. Cells were analysed by real-time PCR, immunofluorescence, flow cytometry, microscopy and functional assays. Furthermore, microarray analysis was performed. RESULTS We demonstrated that overexpression of miR-122 could effectively promote hepatic differentiation and maturation, as assessed by morphological and functional tests. The microarray analysis revealed that 323 genes were down-regulated, whereas 59 were up-regulated. Particularly, two liver-specific transcription factors, FoxA1 and HNF4a, were significantly up-regulated. Moreover, the expression of E-cadherin was dramatically increased and the proliferation of HPCs was suppressed, whereas knockdown of FoxA1 reduced E-cadherin expression and increased the proliferation of HPCs. In addition, the expression levels of FoxA1, HNF4a and E-cadherin in time-course transfection experiments with miR-122 were not significantly increased except in cells in which transfection with miR-122 occurred 9 days after induction. CONCLUSION Overexpression of miR-122 at an appropriate stage could promote hepatic differentiation and maturation by regulating the balance between proliferation and differentiation, as well as the balance between EMT and MET, partially through a miR-122/FoxA1/HNF4a-positive feedback loop.
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Affiliation(s)
- Xiao-Geng Deng
- Department of Pediatric Surgery, The Memorial Hospital of Sun Yat-Sen University, Guangzhou, China
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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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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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Smith ER, Cai MM, McMahon LP, Holt SG. Biological variability of plasma intact and C-terminal FGF23 measurements. J Clin Endocrinol Metab 2012; 97:3357-65. [PMID: 22689697 DOI: 10.1210/jc.2012-1811] [Citation(s) in RCA: 151] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
CONTEXT FGF23 measurement may have a role in the management of patients with chronic kidney disease (CKD). OBJECTIVE Our objective was to study the biological variability of plasma intact FGF23 (iFGF23) and C-terminal FGF23 (cFGF23) concentrations. DESIGN Plasma samples were taken from 12 healthy adults at multiple time points on 2 consecutive days to assess diurnal variability of FGF23 concentrations. Early-morning fasting and nonfasting samples were also taken over a 6-wk period to estimate components of biological variation. Samples from 170 volunteers were used to define reference intervals. FGF23 concentrations were measured by commercial ELISA. Western blotting was used to analyze FGF23 species from the plasma of healthy adults and patients with predialysis CKD and those undergoing dialysis. PARTICIPANTS AND SETTING A total of 180 healthy adults and 18 adults with stage 3-5D CKD participated in this study at a hospital research unit. MAIN OUTCOME MEASURE Estimates were made of the biological variability of plasma FGF23 concentrations. RESULTS iFGF23, but not cFGF23, showed significant diurnal variation. cFGF23 had a significantly lower intra-individual variation than iFGF23 (8.3 vs. 18.3%) but higher inter-individual variation than iFGF23 (28.9 vs. 19.2%). Fourteen samples would be needed to estimate an individual's homeostatic set point (within 10%) for iFGF23 compared with only three samples for cFGF23. Using Western blotting, C-terminal FGF23 fragments were detected in the plasma of individuals with normal renal function and at all stages of renal disease. The percent cFGF23 was significantly higher in those without renal impairment (P < 0.001) and was positively correlated with plasma phosphate concentration in those with normal renal function. CONCLUSIONS The high intra-individual biological variability of iFGF23 may limit its clinical use as a diagnostic or management tool. Risk-related thresholds may be more appropriate for clinical decision making based on cFGF23 measurements than conventional reference intervals. FGF23 cleavage pathways may be an important natural regulatory mechanism for phosphate control.
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Affiliation(s)
- Edward R Smith
- Department of Renal Medicine, Eastern Health Clinical School, Faculty of Medicine, Nursing and Health Sciences, Monash University, Level 2, 5 Arnold Street, Box Hill, 3128 Victoria, Australia.
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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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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: 592] [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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Bergwitz C, Jüppner H. FGF23 and syndromes of abnormal renal phosphate handling. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 728:41-64. [PMID: 22396161 DOI: 10.1007/978-1-4614-0887-1_3] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Fibroblast growth factor 23 (FGF23) is part of a previously unrecognized hormonal bone-parathyroid-kidney axis, which is modulated by 1,25(OH)(2)-vitamin D (1,25(OH)(2)D), dietary and circulating phosphate and possibly PTH. FGF23 was discovered as the humoral factor in tumors that causes hypophosphatemia and osteomalacia and through the identification of a mutant form of FGF23 that leads to autosomal dominant hypophosphatemic rickets (ADHR), a rare genetic disorder. FGF23 appears to be mainly secreted by osteocytes where its expression is up-regulated by 1,25(OH)(2)D and probably by increased serum phosphate levels. Its synthesis and secretion is reduced through yet unknown mechanisms that involve the phosphate-regulating gene with homologies to endopeptidases on the X chromosome (PHEX), dentin matrix protein 1 (DMP1) and ecto-nucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1). Consequently, loss-of-function mutations in these genes underlie hypophosphatemic disorders that are either X-linked or autosomal recessive. Impaired O-glycosylation of FGF23 due to the lack of UDP-N-acetyl-alpha-D-galactosamine:polypeptide N-acetylgalactosaminyl-transferase 3 (GALNT3) or due to certain homozygous FGF23 mutations results in reduced secretion of intact FGF23 and leads to familial hyperphosphatemic tumoral calcinosis. FGF23 acts through FGF-receptors and the coreceptor Klotho to reduce 1,25(OH)(2)D synthesis in the kidney and probably the synthesis of parathyroid hormone (PTH) by the parathyroid glands. It furthermore synergizes with PTH to increase renal phosphate excretion by reducing expression of the sodium-phosphate cotransporters NaPi-IIa and NaPi-IIc in the proximal tubules. Loss-of-function mutations in these two transporters lead to autosomal recessive Fanconi syndrome or to hereditary hypophosphatemic rickets with hypercalciuria, respectively.
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Li Z, Yamada S, Inenaga S, Imamura T, Wu Y, Wang KY, Shimajiri S, Nakano R, Izumi H, Kohno K, Sasaguri Y. Polypeptide N-acetylgalactosaminyltransferase 6 expression in pancreatic cancer is an independent prognostic factor indicating better overall survival. Br J Cancer 2011; 104:1882-9. [PMID: 21587259 PMCID: PMC3111199 DOI: 10.1038/bjc.2011.166] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Revised: 04/14/2011] [Accepted: 04/17/2011] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND The family of polypeptide N-acetylgalactosaminyltransferases (GalNAc-Ts) is responsible for the altered glycosylation in cancer. The purpose of our study was to investigate the clinical significance of two isoforms, GalNAc-T6 and -T3, and their correlation with the prognosis of pancreatic cancer. METHODS Immunohistochemistry was used to analyse GalNAc-T6 and -T3 expressions in 70 clinicopathologically characterised pancreatic cancer cases. RESULTS Positive expressions of GalNAc-T6 and -T3 were immunohistochemically identified in 51% (36 of 70) and in 77% (54 of 70) of patients, respectively. A close relationship was noted between GalNAc-T6 positive expression and pathological well/moderate differentiated type (P=0.001), small tumour size (P=0.044), absence of vascular invasion (P=0.009), and low stage of the American Joint Committee on Cancer systems (P=0.043). The expression of GalNAc-T3 significantly correlated with good differentiation (P=0.001), but not with other clinicopathologic features. Furthermore, univariate and multivariate analyses revealed that GalNAc-T6 expression was an independent prognosis indicator for the disease, whereas GalNAc-T3 expression had no impact on clinical outcome, even though 33 of 36 GalNAc-T6-positive cases also had a positive expression of GalNAc-T3 (P=0.001, r=0.356). CONCLUSION Both GalNAc-T6 and -T3 expressions correlated significantly with tumour differentiation, whereas only GalNAc-T6 expression predicted prognosis in pancreatic cancer.
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Affiliation(s)
- Z Li
- Department of Pathology and Cell Biology, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu 807-8555, Japan
- Department of Molecular Biology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu 807-8555, Japan
- Department of Medical Oncology, The First Hospital of China Medical University, Shenyang 110001, People's Republic of China
| | - S Yamada
- Department of Pathology and Cell Biology, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu 807-8555, Japan
| | - S Inenaga
- Department of Pathology, Kyushu Kosei-Nenkin Hospital, Kitakyushu 806-8501, Japan
| | - T Imamura
- Department of Surgery, Tobata Kyoritsu Hospital, Kitakyushu 804-0093, Japan
| | - Y Wu
- Department of Pathology and Cell Biology, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu 807-8555, Japan
- Department of Molecular Biology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu 807-8555, Japan
- Department of Medical Oncology, The First Hospital of China Medical University, Shenyang 110001, People's Republic of China
| | - K-Y Wang
- Department of Pathology and Cell Biology, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu 807-8555, Japan
| | - S Shimajiri
- Department of Pathology and Cell Biology, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu 807-8555, Japan
- Department of Pathology, Kyushu Kosei-Nenkin Hospital, Kitakyushu 806-8501, Japan
| | - R Nakano
- Department of Pathology, Kyushu Kosei-Nenkin Hospital, Kitakyushu 806-8501, Japan
| | - H Izumi
- Department of Molecular Biology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu 807-8555, Japan
| | - K Kohno
- Department of Molecular Biology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu 807-8555, Japan
| | - Y Sasaguri
- Department of Pathology and Cell Biology, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu 807-8555, Japan
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Bergwitz C, Jüppner H. Phosphate sensing. Adv Chronic Kidney Dis 2011; 18:132-44. [PMID: 21406298 PMCID: PMC3059779 DOI: 10.1053/j.ackd.2011.01.004] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2010] [Revised: 01/10/2011] [Accepted: 01/17/2011] [Indexed: 02/07/2023]
Abstract
Human phosphate homeostasis is regulated at the level of intestinal absorption of phosphate from the diet, release of phosphate through bone resorption, and renal phosphate excretion, and involves the actions of parathyroid hormone, 1,25-dihydroxy-vitamin D, and fibroblast growth factor 23 to maintain circulating phosphate levels within a narrow normal range, which is essential for numerous cellular functions, for the growth of tissues and for bone mineralization. Prokaryotic and single cellular eukaryotic organisms such as bacteria and yeast "sense" ambient phosphate with a multi-protein complex located in their plasma membrane, which modulates the expression of genes important for phosphate uptake and metabolism (pho pathway). Database searches based on amino acid sequence conservation alone have been unable to identify metazoan orthologs of the bacterial and yeast phosphate sensors. Thus, little is known about how human and other metazoan cells sense inorganic phosphate to regulate the effects of phosphate on cell metabolism ("metabolic" sensing) or to regulate the levels of extracellular phosphate through feedback system(s) ("endocrine" sensing). Whether the "metabolic" and the "endocrine" sensor use the same or different signal transduction cascades is unknown. This article will review the bacterial and yeast phosphate sensors, and then discuss what is currently known about the metabolic and endocrine effects of phosphate in multicellular organisms and human beings.
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Affiliation(s)
- Clemens Bergwitz
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
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Khoshniat S, Bourgine A, Julien M, Weiss P, Guicheux J, Beck L. The emergence of phosphate as a specific signaling molecule in bone and other cell types in mammals. Cell Mol Life Sci 2011; 68:205-18. [PMID: 20848155 PMCID: PMC11114507 DOI: 10.1007/s00018-010-0527-z] [Citation(s) in RCA: 116] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2010] [Revised: 08/02/2010] [Accepted: 08/31/2010] [Indexed: 02/07/2023]
Abstract
Although considerable advances in our understanding of the mechanisms of phosphate homeostasis and skeleton mineralization have recently been made, little is known about the initial events involving the detection of changes in the phosphate serum concentrations and the subsequent downstream regulation cascade. Recent data has strengthened a long-established hypothesis that a phosphate-sensing mechanism may be present in various organs. Such a phosphate sensor would detect changes in serum or local phosphate concentration and would inform the body, the local environment, or the individual cell. This suggests that phosphate in itself could represent a signal regulating multiple factors necessary for diverse biological processes such as bone or vascular calcification. This review summarizes findings supporting the possibility that phosphate represents a signaling molecule, particularly in bone and cartilage, but also in other tissues. The involvement of various signaling pathways (ERK1/2), transcription factors (Fra-1, Runx2) and phosphate transporters (PiT1, PiT2) is discussed.
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Affiliation(s)
- Solmaz Khoshniat
- Group STEP (Skeletal Tissue Engineering and Physiopathology), Centre for Osteoarticular and Dental Tissue Engineering (LIOAD), INSERM, U791, 44042 Nantes, France
- UFR Odontologie, Pres UNAM, 44042 Nantes, France
| | - Annabelle Bourgine
- Group STEP (Skeletal Tissue Engineering and Physiopathology), Centre for Osteoarticular and Dental Tissue Engineering (LIOAD), INSERM, U791, 44042 Nantes, France
- UFR Odontologie, Pres UNAM, 44042 Nantes, France
| | - Marion Julien
- Group STEP (Skeletal Tissue Engineering and Physiopathology), Centre for Osteoarticular and Dental Tissue Engineering (LIOAD), INSERM, U791, 44042 Nantes, France
- UFR Odontologie, Pres UNAM, 44042 Nantes, France
| | - Pierre Weiss
- Group STEP (Skeletal Tissue Engineering and Physiopathology), Centre for Osteoarticular and Dental Tissue Engineering (LIOAD), INSERM, U791, 44042 Nantes, France
- UFR Odontologie, Pres UNAM, 44042 Nantes, France
| | - Jérôme Guicheux
- Group STEP (Skeletal Tissue Engineering and Physiopathology), Centre for Osteoarticular and Dental Tissue Engineering (LIOAD), INSERM, U791, 44042 Nantes, France
- UFR Odontologie, Pres UNAM, 44042 Nantes, France
| | - Laurent Beck
- Growth and Signalling Research Center, INSERM, U845, 75015 Paris, France
- Faculté de Médecine, Centre de Recherche, INSERM U845, Université Paris Descartes, 156 Rue de Vaugirard, 75015 Paris, France
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Schjoldager KTBG, Vester-Christensen MB, Bennett EP, Levery SB, Schwientek T, Yin W, Blixt O, Clausen H. O-glycosylation modulates proprotein convertase activation of angiopoietin-like protein 3: possible role of polypeptide GalNAc-transferase-2 in regulation of concentrations of plasma lipids. J Biol Chem 2010; 285:36293-303. [PMID: 20837471 PMCID: PMC2978557 DOI: 10.1074/jbc.m110.156950] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Revised: 09/10/2010] [Indexed: 01/17/2023] Open
Abstract
The angiopoietin-like protein 3 (ANGPTL3) is an important inhibitor of the endothelial and lipoprotein lipases and a promising drug target. ANGPTL3 undergoes proprotein convertase processing (RAPR(224)↓TT) for activation, and the processing site contains two potential GalNAc O-glycosylation sites immediately C-terminal (TT(226)). We developed an in vivo model system in CHO ldlD cells that was used to show that O-glycosylation in the processing site blocked processing of ANGPTL3. Genome-wide SNP association studies have identified the polypeptide GalNAc-transferase gene, GALNT2, as a candidate gene for low HDL and high triglyceride blood levels. We hypothesized that the GalNAc-T2 transferase performed critical O-glycosylation of proteins involved in lipid metabolism. Screening of a panel of proteins known to affect lipid metabolism for potential sites glycosylated by GalNAc-T2 led to identification of Thr(226) adjacent to the proprotein convertase processing site in ANGPTL3. We demonstrated that GalNAc-T2 glycosylation of Thr(226) in a peptide with the RAPR(224)↓TT processing site blocks in vitro furin cleavage. The study demonstrates that ANGPTL3 activation is modulated by O-glycosylation and that this step is probably controlled by GalNAc-T2.
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Affiliation(s)
- Katrine T.-B. G. Schjoldager
- From the Center for Glycomics, Departments of Cellular and Molecular Medicine and School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Malene B. Vester-Christensen
- From the Center for Glycomics, Departments of Cellular and Molecular Medicine and School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Eric Paul Bennett
- From the Center for Glycomics, Departments of Cellular and Molecular Medicine and School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Steven B. Levery
- From the Center for Glycomics, Departments of Cellular and Molecular Medicine and School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Tilo Schwientek
- Medical Biochemistry II, Universitaet Köln, 50923 Köln, Germany
| | - Wu Yin
- the Howard Hughes Medical Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, and
| | - Ola Blixt
- From the Center for Glycomics, Departments of Cellular and Molecular Medicine and School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Henrik Clausen
- From the Center for Glycomics, Departments of Cellular and Molecular Medicine and School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
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The osteocyte--a novel endocrine regulator of body phosphate homeostasis. Maturitas 2010; 67:327-38. [PMID: 20884141 DOI: 10.1016/j.maturitas.2010.08.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Revised: 08/27/2010] [Accepted: 08/30/2010] [Indexed: 11/22/2022]
Abstract
Although osteocytes are the most abundant cell type in bone, much of their biology remains enigmatic. They are known to transduce mechanical stress into signals that initiate local bone remodeling, and are targets for systemic and local endocrine signals that affect bone architecture and mineral homeostasis. However, recent data reveal that osteocytes themselves act as endocrine cells that synthesize fibroblast growth factor 23 (FGF23) and several other phosphatonins, shown to underpin the systemic regulation of phosphate homeostasis. This review will synthesize the emerging discoveries concerning the osteocytic endocrine role in phosphate homeostasis through the biology and pathophysiology of these phosphatonins. We also suggest future research paths that might resolve existing uncertainties, and look ahead at how greater understanding might improve the management of clinical disorders of phosphate homeostasis.
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Takaiwa M, Aya K, Miyai T, Hasegawa K, Yokoyama M, Kondo Y, Kodani N, Seino Y, Tanaka H, Morishima T. Fibroblast growth factor 23 concentrations in healthy term infants during the early postpartum period. Bone 2010; 47:256-262. [PMID: 20638950 DOI: 10.1016/j.bone.2010.05.024] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2010] [Revised: 05/13/2010] [Accepted: 05/18/2010] [Indexed: 01/21/2023]
Abstract
Fibroblast growth factor 23 (FGF23) is a potent regulator of Pi and 1,25-(OH)(2)D homeostasis. Early postpartum infants show intriguing changes in serum levels of Ca, Pi, PTH and 1,25-(OH)(2)D. However, the role of FGF23 in the early neonatal mineral metabolism has not been clarified. In order to evaluate the significance of FGF23 during the early postpartum period, we examined the circulating FGF23 levels using an intact FGF23 ELISA and a C-terminal FGF23 ELISA either in 22 umbilical cord blood samples (the cord blood) or in 22 term infants at 5days of life (the 5-day-old infant). We also compared these ranges with those of 11 healthy adults. Data were expressed as mean+/-SD, and analyzed by two-way ANOVA, followed by the Tukey's test. C-terminal FGF23 in the cord blood, the 5-day-old infants and the healthy adults were 73.3+/-22.4, 81.0+/-28.2 and 39.0+/-7.8 RU/ml, respectively. Intact FGF23 in the cord blood, the 5-day-old infants and the healthy adults were 3.9+/-1.6, 21.8+/-17.6, and 27.6+/-7.3 pg/ml, respectively. Immunoprecipitation assays using anti-FGF23 antibodies demonstrated that the intact 32 kDa FGF23 was low and the fragmented FGF23 of 18kDa was abundant in the cord blood compared with those in the healthy adults. In conclusion, our observations indicated that the intact FGF23/C-terminal FGF23 ratio was very low due to the fragmentation of FGF23 during the early postpartum period and might have a considerable contribution to the Pi homeostasis in the healthy term infants.
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Affiliation(s)
- Masanori Takaiwa
- Department of Pediatrics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan; Department of Pediatrics, Matsuyama Red Cross Hospital, Ehime, Japan
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Abstract
In contrast to the regulation of calcium homeostasis, which has been extensively studied over the past several decades, relatively little is known about the regulation of phosphate homeostasis. Fibroblast growth factor 23 (FGF23) is part of a previously unrecognized hormonal bone-parathyroid-kidney axis, which is modulated by PTH, 1,25(OH)(2)-vitamin D (1,25(OH)(2)D), dietary and serum phosphorus levels. Synthesis and secretion of FGF23 by osteocytes are positively regulated by 1,25(OH)(2)D and serum phosphorus and negatively regulated, through yet unknown mechanisms, by the phosphate-regulating gene with homologies to endopeptidases on the X chromosome (PHEX) and by dentin matrix protein 1 (DMP1). In turn, FGF23 inhibits the synthesis of 1,25(OH)(2)D, and it may negatively regulate the secretion of parathyroid hormone (PTH) from the parathyroid glands. However, FGF23 synergizes with PTH to increase renal phosphate excretion by reducing expression of the renal sodium-phosphate cotransporters NaPi-IIa and NaPi-IIc in the proximal tubules. Most insights gained into the regulation of phosphate homeostasis by these factors are derived from human genetic disorders and genetically engineered mice, which are reviewed in this paper.
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Affiliation(s)
- Clemens Bergwitz
- Endocrine Unit, Massachusetts General Hospital, Boston, MA 02114, 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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