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Taglia I, Formichi P, Battisti C, Peppoloni G, Barghigiani M, Tessa A, Federico A. Primary familial brain calcification with a novel SLC20A2 mutation: Analysis of PiT-2 expression and localization. J Cell Physiol 2017; 233:2324-2331. [PMID: 28722801 DOI: 10.1002/jcp.26104] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 07/18/2017] [Indexed: 12/11/2022]
Abstract
Primary familial brain calcification (PFBC) is an autosomal dominant rare disorder characterized by bilateral and symmetric brain calcifications, and neuropsychiatric manifestations. Four genes have been linked to PFBC: SLC20A2, PDGFRB, PDGFB, and XPR1. In this study, we report molecular and clinical data of a PFBC patient carrying a novel SLC20A2 mutation and we investigate the impact of the mutation on PiT-2 expression and function. Sanger sequencing of SLC20A2, PDGFRB, PDGFB, XPR1 led to the identification of a novel duplication of twelve nucleotides (c.1876_1887dup/ p.Trp626_Thr629dup) in SLC20A2 gene. SLC20A2 encodes for a cell membrane transporter (PiT-2) involved in maintenance of inorganic phosphate homeostasis. We performed an analysis of expression and functionality of PiT-2 protein in patient primary cultured fibroblasts. In patient fibroblasts, the mutation does not affect PiT-2 expression but alter sub-cellular localization. The Pi-uptake assay revealed a less Pi depletion in patient than in control fibroblasts, suggesting that SLC20A2 duplication may impair Pi internalization. This is the first study reporting sub-cellular expression analysis of mutant PiT-2 in primary cultured fibroblasts from a PFBC patient, showing that p.Trp626_Thr629dup in SLC20A2 alters PiT-2 sub-cellular localization and reduces Pi-uptake, leading to onset of PFBC in our patient.
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Affiliation(s)
- Ilaria Taglia
- Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
| | - Patrizia Formichi
- Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
| | - Carla Battisti
- Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
| | - Giulia Peppoloni
- Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
| | | | - Alessandra Tessa
- Molecular Medicine and Neurogenetics, IRCCS Stella Maris, Pisa, Italy
| | - Antonio Federico
- Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
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Lacruz RS, Habelitz S, Wright JT, Paine ML. DENTAL ENAMEL FORMATION AND IMPLICATIONS FOR ORAL HEALTH AND DISEASE. Physiol Rev 2017; 97:939-993. [PMID: 28468833 DOI: 10.1152/physrev.00030.2016] [Citation(s) in RCA: 223] [Impact Index Per Article: 31.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 01/10/2017] [Accepted: 01/10/2017] [Indexed: 12/16/2022] Open
Abstract
Dental enamel is the hardest and most mineralized tissue in extinct and extant vertebrate species and provides maximum durability that allows teeth to function as weapons and/or tools as well as for food processing. Enamel development and mineralization is an intricate process tightly regulated by cells of the enamel organ called ameloblasts. These heavily polarized cells form a monolayer around the developing enamel tissue and move as a single forming front in specified directions as they lay down a proteinaceous matrix that serves as a template for crystal growth. Ameloblasts maintain intercellular connections creating a semi-permeable barrier that at one end (basal/proximal) receives nutrients and ions from blood vessels, and at the opposite end (secretory/apical/distal) forms extracellular crystals within specified pH conditions. In this unique environment, ameloblasts orchestrate crystal growth via multiple cellular activities including modulating the transport of minerals and ions, pH regulation, proteolysis, and endocytosis. In many vertebrates, the bulk of the enamel tissue volume is first formed and subsequently mineralized by these same cells as they retransform their morphology and function. Cell death by apoptosis and regression are the fates of many ameloblasts following enamel maturation, and what cells remain of the enamel organ are shed during tooth eruption, or are incorporated into the tooth's epithelial attachment to the oral gingiva. In this review, we examine key aspects of dental enamel formation, from its developmental genesis to the ever-increasing wealth of data on the mechanisms mediating ionic transport, as well as the clinical outcomes resulting from abnormal ameloblast function.
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Affiliation(s)
- Rodrigo S Lacruz
- Department of Basic Science and Craniofacial Biology, College of Dentistry, New York University, New York, New York; Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, San Francisco, California; Department of Pediatric Dentistry, School of Dentistry, University of North Carolina, Chapel Hill, North Carolina; Herman Ostrow School of Dentistry, Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, California
| | - Stefan Habelitz
- Department of Basic Science and Craniofacial Biology, College of Dentistry, New York University, New York, New York; Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, San Francisco, California; Department of Pediatric Dentistry, School of Dentistry, University of North Carolina, Chapel Hill, North Carolina; Herman Ostrow School of Dentistry, Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, California
| | - J Timothy Wright
- Department of Basic Science and Craniofacial Biology, College of Dentistry, New York University, New York, New York; Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, San Francisco, California; Department of Pediatric Dentistry, School of Dentistry, University of North Carolina, Chapel Hill, North Carolina; Herman Ostrow School of Dentistry, Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, California
| | - Michael L Paine
- Department of Basic Science and Craniofacial Biology, College of Dentistry, New York University, New York, New York; Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, San Francisco, California; Department of Pediatric Dentistry, School of Dentistry, University of North Carolina, Chapel Hill, North Carolina; Herman Ostrow School of Dentistry, Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, California
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Abstract
PURPOSE OF REVIEW We give an update on the etiology and potential treatment options of rare inherited monogenic disorders associated with arterial calcification and calcific cardiac valve disease. RECENT FINDINGS Genetic studies of rare inherited syndromes have identified key regulators of ectopic calcification. Based on the pathogenic principles causing the diseases, these can be classified into three groups: (1) disorders of an increased extracellular inorganic phosphate/inorganic pyrophosphate ratio (generalized arterial calcification of infancy, pseudoxanthoma elasticum, arterial calcification and distal joint calcification, progeria, idiopathic basal ganglia calcification, and hyperphosphatemic familial tumoral calcinosis; (2) interferonopathies (Singleton-Merten syndrome); and (3) others, including Keutel syndrome and Gaucher disease type IIIC. Although some of the identified causative mechanisms are not easy to target for treatment, it has become clear that a disturbed serum phosphate/pyrophosphate ratio is a major force triggering arterial and cardiac valve calcification. Further studies will focus on targeting the phosphate/pyrophosphate ratio to effectively prevent and treat these calcific disease phenotypes.
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MESH Headings
- Abnormalities, Multiple/drug therapy
- Abnormalities, Multiple/genetics
- Abnormalities, Multiple/metabolism
- Aortic Diseases/drug therapy
- Aortic Diseases/genetics
- Aortic Diseases/metabolism
- Basal Ganglia Diseases/drug therapy
- Basal Ganglia Diseases/genetics
- Basal Ganglia Diseases/metabolism
- Calcinosis/drug therapy
- Calcinosis/genetics
- Calcinosis/metabolism
- Cartilage Diseases/drug therapy
- Cartilage Diseases/genetics
- Cartilage Diseases/metabolism
- Dental Enamel Hypoplasia/drug therapy
- Dental Enamel Hypoplasia/genetics
- Dental Enamel Hypoplasia/metabolism
- Diphosphates/metabolism
- Enzyme Replacement Therapy
- Gaucher Disease/drug therapy
- Gaucher Disease/genetics
- Gaucher Disease/metabolism
- Hand Deformities, Congenital/drug therapy
- Hand Deformities, Congenital/genetics
- Hand Deformities, Congenital/metabolism
- Humans
- Hyperostosis, Cortical, Congenital/drug therapy
- Hyperostosis, Cortical, Congenital/genetics
- Hyperostosis, Cortical, Congenital/metabolism
- Hyperphosphatemia/drug therapy
- Hyperphosphatemia/genetics
- Hyperphosphatemia/metabolism
- Interferons/metabolism
- Metacarpus/abnormalities
- Metacarpus/metabolism
- Muscular Diseases/drug therapy
- Muscular Diseases/genetics
- Muscular Diseases/metabolism
- Odontodysplasia/drug therapy
- Odontodysplasia/genetics
- Odontodysplasia/metabolism
- Osteoporosis/drug therapy
- Osteoporosis/genetics
- Osteoporosis/metabolism
- Phosphates/metabolism
- Progeria/drug therapy
- Progeria/genetics
- Progeria/metabolism
- Pseudoxanthoma Elasticum/drug therapy
- Pseudoxanthoma Elasticum/genetics
- Pseudoxanthoma Elasticum/metabolism
- Pulmonary Valve Stenosis/drug therapy
- Pulmonary Valve Stenosis/genetics
- Pulmonary Valve Stenosis/metabolism
- Vascular Calcification/drug therapy
- Vascular Calcification/genetics
- Vascular Calcification/metabolism
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Affiliation(s)
- Yvonne Nitschke
- Department of General Pediatrics, Münster University Children's Hospital, Albert-Schweitzer-Campus 1, D-48149, Münster, Germany
| | - Frank Rutsch
- Department of General Pediatrics, Münster University Children's Hospital, Albert-Schweitzer-Campus 1, D-48149, Münster, Germany.
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54
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Dietrich P, Johnson IM, Alli S, Dragatsis I. Elimination of huntingtin in the adult mouse leads to progressive behavioral deficits, bilateral thalamic calcification, and altered brain iron homeostasis. PLoS Genet 2017; 13:e1006846. [PMID: 28715425 PMCID: PMC5536499 DOI: 10.1371/journal.pgen.1006846] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 07/31/2017] [Accepted: 06/01/2017] [Indexed: 02/07/2023] Open
Abstract
Huntington's Disease (HD) is an autosomal dominant progressive neurodegenerative disorder characterized by cognitive, behavioral and motor dysfunctions. HD is caused by a CAG repeat expansion in exon 1 of the HD gene that is translated into an expanded polyglutamine tract in the encoded protein, huntingtin (HTT). While the most significant neuropathology of HD occurs in the striatum, other brain regions are also affected and play an important role in HD pathology. To date there is no cure for HD, and recently strategies aiming at silencing HTT expression have been initiated as possible therapeutics for HD. However, the essential functions of HTT in the adult brain are currently unknown and hence the consequence of sustained suppression of HTT expression is unpredictable and can potentially be deleterious. Using the Cre-loxP system of recombination, we conditionally inactivated the mouse HD gene homologue at 3, 6 and 9 months of age. Here we show that elimination of Htt expression in the adult mouse results in behavioral deficits, progressive neuropathological changes including bilateral thalamic calcification, and altered brain iron homeostasis.
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Affiliation(s)
- Paula Dietrich
- Department of Physiology, The University of Tennessee, Health Science Center, Memphis, Tennessee, United States of America
| | - Irudayam Maria Johnson
- Department of Physiology, The University of Tennessee, Health Science Center, Memphis, Tennessee, United States of America
| | - Shanta Alli
- Department of Physiology, The University of Tennessee, Health Science Center, Memphis, Tennessee, United States of America
| | - Ioannis Dragatsis
- Department of Physiology, The University of Tennessee, Health Science Center, Memphis, Tennessee, United States of America
- * E-mail:
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55
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Pasanen P, Mäkinen J, Myllykangas L, Guerreiro R, Bras J, Valori M, Viitanen M, Baumann M, Tienari PJ, Pöyhönen M, Baumann P. Primary familial brain calcification linked to deletion of 5' noncoding region of SLC20A2. Acta Neurol Scand 2017; 136:59-63. [PMID: 27726124 DOI: 10.1111/ane.12697] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/19/2016] [Indexed: 12/17/2022]
Abstract
OBJECTIVES Primary familial brain calcification (PFBC) is a rare neurological disease often inherited as a dominant trait. Mutations in four genes (SLC20A2, PDGFB, PDGFRB, and XPR1) have been reported in patients with PFBC. Of these, point mutations or small deletions in SLC20A2 are most common. Thus far, only one large deletion covering entire SLC20A2 and several smaller, exonic deletions of SLC20A2 have been reported. The aim of this study was to identify the causative gene defect in a Finnish PFBC family with three affected patients. MATERIALS AND METHODS A Finnish family with three PFBC patients and five unaffected subjects was studied. Sanger sequencing was used to exclude mutations in the coding and splice site regions of SLC20A2, PDGFRB, and PDGFB. Whole-exome (WES) and whole-genome sequencing (WGS) were performed to identify the causative mutation. A SNP array was used in segregation analysis. RESULTS Copy number analysis of the WGS data revealed a heterozygous deletion of ~578 kb on chromosome 8. The deletion removes the 5' UTR region, the noncoding exon 1 and the putative promoter region of SLC20A2 as well as the coding regions of six other genes. CONCLUSIONS Our results support haploinsufficiency of SLC20A2 as a pathogenetic mechanism in PFBC. Analysis of copy number variations (CNVs) is emerging as a crucial step in the molecular genetic diagnostics of PFBC, and it should not be limited to coding regions, as causative variants may reside in the noncoding parts of known disease-associated genes.
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Affiliation(s)
- P. Pasanen
- Department of Medical Biochemistry and Genetics; University of Turku; Turku Finland
- Tyks Microbiology and Genetics; Department of Medical Genetics; Turku University Hospital; Turku Finland
| | - J. Mäkinen
- Department of Neurology; Tampere University Hospital; Tampere Finland
| | - L. Myllykangas
- Department of Pathology; University of Helsinki and HUSLAB; Helsinki Finland
| | - R. Guerreiro
- Department of Molecular Neuroscience; UCL Institute of Neurology; London UK
- Department of Medical Sciences and Institute of Biomedicine - iBiMED; University of Aveiro; Aveiro Portugal
| | - J. Bras
- Department of Molecular Neuroscience; UCL Institute of Neurology; London UK
- Department of Medical Sciences and Institute of Biomedicine - iBiMED; University of Aveiro; Aveiro Portugal
| | - M. Valori
- Research Programs Unit; Molecular Neurology; University of Helsinki; Helsinki Finland
| | - M. Viitanen
- Department of Geriatrics; University of Turku; Turku Finland
- Department of Neurobiology; Care Sciences and Society; Karolinska Institutet; Stockholm Sweden
| | - M. Baumann
- Biochemistry/Developmental Biology; Meilahti Clinical Proteomics Core Facility; University of Helsinki; Helsinki Finland
| | - P. J. Tienari
- Research Programs Unit; Molecular Neurology; University of Helsinki; Helsinki Finland
- Clinical Neurosciences; Neurology; University of Helsinki and Helsinki University Hospital; Helsinki Finland
| | - M. Pöyhönen
- Department of Clinical Genetics; Helsinki University Central Hospital and Department of Medical Genetics; University of Helsinki; Helsinki Finland
| | - P. Baumann
- Department of Neurology and Clinical Neurophysiology; Lapland Central Hospital; Rovaniemi Finland
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56
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Phosphate Transporters Expression in Patients with Primary Familial Brain Calcifications. J Mol Neurosci 2017; 62:276-280. [DOI: 10.1007/s12031-017-0934-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 05/26/2017] [Indexed: 12/26/2022]
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57
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MiR-9-5p Down-Regulates PiT2, but not PiT1 in Human Embryonic Kidney 293 Cells. J Mol Neurosci 2017; 62:28-33. [PMID: 28303467 DOI: 10.1007/s12031-017-0906-0] [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: 09/23/2016] [Accepted: 02/27/2017] [Indexed: 10/20/2022]
Abstract
PiT1 (SLC20A1) and PiT2 (SLC20A2) are members of the mammalian type-III inorganic phosphate transporters and recent studies linked SLC20A2 mutations with primary brain calcifications. MicroRNAs (miRNAs) are endogenous noncoding regulatory RNAs and MicroRNA-9 (miR-9) modulates neurogenesis but is also involved with different types of cancer. We evaluated possible interactions between miR-9 and the phosphate transporters (PiT1 and PiT2). SLC20A2, platelet-derived growth factor receptor beta (PDGFRB) and Fibrillin-2 (FBN2) showed binding sites with high affinity for mir-9, In silico. miR-9 mimic was transfected into HEK293 cells and expression was confirmed by RT-qPCR. Overexpression of miR-9 in these cells caused a significant reduction in PiT2 and FBN2. PDGFRB appeared to be decreased, but was not significantly down-regulated. PiT1 showed no significant difference relative to controls. The down-regulation of PiT2 protein by miR-9 was confirmed by western blotting. In conclusion, we showed that miR-9 can down-regulate PiT2, in HEK293 cells. [corrected].
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58
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Larsen FT, Jensen N, Autzen JK, Kongsfelt IB, Pedersen L. Primary Brain Calcification Causal PiT2 Transport-Knockout Variants can Exert Dominant Negative Effects on Wild-Type PiT2 Transport Function in Mammalian Cells. J Mol Neurosci 2016; 61:215-220. [PMID: 27943094 PMCID: PMC5321689 DOI: 10.1007/s12031-016-0868-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2016] [Accepted: 11/22/2016] [Indexed: 12/31/2022]
Abstract
Primary brain calcification (PBC) is a neurodegenerative disorder characterized by calcium-phosphate deposits in the basal ganglia and often also other areas of the brain. The prevalent clinical manifestations are cognitive impairment, neuropsychiatric symptoms, and movement disorders. In recent years, monoallelic variants in SLC20A2, which encodes the type III sodium-dependent inorganic phosphate (Pi) transporter 2 (PiT2), have been linked to the familial form of PBC in 40–50% of the families reported worldwide as well as to sporadic cases of PBC. Further insight into the disease mechanism is, however, needed. Based on co-expression studies of wild-type and variant PiT2 in Xenopus laevis oocytes, the molecular disease mechanism associated with SLC20A2 missense variants has formerly been suggested to be haploinsufficiency. We have here used mammalian cells isolated from a Slc20a2−/− mouse and co-expression of human wild-type and variant PiT2. Two of the variants studied have both been reported twice in unrelated PBC cases: PiT2D28N in two sporadic cases and PiT2E575K in a familial and a sporadic case. We find that in mammalian cells, the analyzed SLC20A2 missense variants can exert their effect in a dominant negative manner resulting in decreased wild-type PiT2 Pi transport. Thus, compared to monoallelic lack of functional PiT2 protein expression, which reasonably points towards haploinsufficiency, certain SLC20A2 missense variants may be more detrimental for cellular Pi uptake and potentially contribute to an earlier disease onset and/or a more severe phenotype as observed for Slc20a2−/− mice compared to Slc20a2+/− mice.
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Affiliation(s)
- Frederik Tibert Larsen
- Department of Molecular Biology and Genetics, Aarhus University, C. F. Møllers Allé 3, Building 1130, 8000, Aarhus, Denmark
| | - Nina Jensen
- Department of Molecular Biology and Genetics, Aarhus University, C. F. Møllers Allé 3, Building 1130, 8000, Aarhus, Denmark.,Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Jacob Kwasi Autzen
- Department of Molecular Biology and Genetics, Aarhus University, C. F. Møllers Allé 3, Building 1130, 8000, Aarhus, Denmark
| | - Iben Boutrup Kongsfelt
- Department of Molecular Biology and Genetics, Aarhus University, C. F. Møllers Allé 3, Building 1130, 8000, Aarhus, Denmark
| | - Lene Pedersen
- Department of Molecular Biology and Genetics, Aarhus University, C. F. Møllers Allé 3, Building 1130, 8000, Aarhus, Denmark. .,Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
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59
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Bezerra DP, Oliveira JRM. New Studies on Knockout Mouse for the SLC20A2 Gene Show Much More Than Brain Calcifications. J Mol Neurosci 2016; 59:565-6. [PMID: 27380911 DOI: 10.1007/s12031-016-0778-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 06/17/2016] [Indexed: 02/07/2023]
Affiliation(s)
- D P Bezerra
- Keizo Asami Laboratory-Federal University of Pernambuco (UFPE), Recife, PE, Brazil.,Biological Sciences Graduate Program, UFPE, Recife, PE, Brazil
| | - J R M Oliveira
- Keizo Asami Laboratory-Federal University of Pernambuco (UFPE), Recife, PE, Brazil. .,Biological Sciences Graduate Program, UFPE, Recife, PE, Brazil. .,Neuropsychiatry Department, UFPE, Recife, PE, Brazil.
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60
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Pesta DH, Tsirigotis DN, Befroy DE, Caballero D, Jurczak MJ, Rahimi Y, Cline GW, Dufour S, Birkenfeld AL, Rothman DL, Carpenter TO, Insogna K, Petersen KF, Bergwitz C, Shulman GI. Hypophosphatemia promotes lower rates of muscle ATP synthesis. FASEB J 2016; 30:3378-3387. [PMID: 27338702 PMCID: PMC5024687 DOI: 10.1096/fj.201600473r] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 06/14/2016] [Indexed: 12/13/2022]
Abstract
Hypophosphatemia can lead to muscle weakness and respiratory and heart failure, but the mechanism is unknown. To address this question, we noninvasively assessed rates of muscle ATP synthesis in hypophosphatemic mice by using in vivo saturation transfer [31P]-magnetic resonance spectroscopy. By using this approach, we found that basal and insulin-stimulated rates of muscle ATP synthetic flux (VATP) and plasma inorganic phosphate (Pi) were reduced by 50% in mice with diet-induced hypophosphatemia as well as in sodium-dependent Pi transporter solute carrier family 34, member 1 (NaPi2a)-knockout (NaPi2a-/-) mice compared with their wild-type littermate controls. Rates of VATP normalized in both hypophosphatemic groups after restoring plasma Pi concentrations. Furthermore, VATP was directly related to cellular and mitochondrial Pi uptake in L6 and RC13 rodent myocytes and isolated muscle mitochondria. Similar findings were observed in a patient with chronic hypophosphatemia as a result of a mutation in SLC34A3 who had a 50% reduction in both serum Pi content and muscle VATP After oral Pi repletion and normalization of serum Pi levels, muscle VATP completely normalized in the patient. Taken together, these data support the hypothesis that decreased muscle ATP synthesis, in part, may be caused by low blood Pi concentrations, which may explain some aspects of muscle weakness observed in patients with hypophosphatemia.-Pesta, D. H., Tsirigotis, D. N., Befroy, D. E., Caballero, D., Jurczak, M. J., Rahimi, Y., Cline, G. W., Dufour, S., Birkenfeld, A. L., Rothman, D. L., Carpenter, T. O., Insogna, K., Petersen, K. F., Bergwitz, C., Shulman, G. I. Hypophosphatemia promotes lower rates of muscle ATP synthesis.
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Affiliation(s)
- Dominik H Pesta
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Dimitrios N Tsirigotis
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Douglas E Befroy
- Department of Radiology and Biomedical Engineering, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Daniel Caballero
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Michael J Jurczak
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Yasmeen Rahimi
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Gary W Cline
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Sylvie Dufour
- Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Andreas L Birkenfeld
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Douglas L Rothman
- Department of Radiology and Biomedical Engineering, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Thomas O Carpenter
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut, USA; and
| | - Karl Insogna
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Kitt Falk Petersen
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA; Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Clemens Bergwitz
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Gerald I Shulman
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA; Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut, USA; Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut, USA; Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
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61
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Suzuki T, Kazuki Y, Oshimura M, Hara T. Highly Efficient Transfer of Chromosomes to a Broad Range of Target Cells Using Chinese Hamster Ovary Cells Expressing Murine Leukemia Virus-Derived Envelope Proteins. PLoS One 2016; 11:e0157187. [PMID: 27271046 PMCID: PMC4896634 DOI: 10.1371/journal.pone.0157187] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 05/25/2016] [Indexed: 12/31/2022] Open
Abstract
Microcell-mediated chromosome transfer (MMCT) is an essential step for introducing chromosomes from donor cells to recipient cells. MMCT allows not only for genetic/epigenetic analysis of specific chromosomes, but also for utilization of human and mouse artificial chromosomes (HACs/MACs) as gene delivery vectors. Although the scientific demand for genome scale analyses is increasing, the poor transfer efficiency of the current method has hampered the application of chromosome engineering technology. Here, we developed a highly efficient chromosome transfer method, called retro-MMCT, which is based on Chinese hamster ovary cells expressing envelope proteins derived from ecotropic or amphotropic murine leukemia viruses. Using this method, we transferred MACs to NIH3T3 cells with 26.5 times greater efficiency than that obtained using the conventional MMCT method. Retro-MMCT was applicable to a variety of recipient cells, including embryonic stem cells. Moreover, retro-MMCT enabled efficient transfer of MAC to recipient cells derived from humans, monkeys, mice, rats, and rabbits. These results demonstrate the utility of retro-MMCT for the efficient transfer of chromosomes to various types of target cell.
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Affiliation(s)
- Teruhiko Suzuki
- Stem Cell Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
- * E-mail:
| | - Yasuhiro Kazuki
- Department of Biomedical Science, Institute of Regenerative Medicine and Biofunction, Graduate School of Medical Science, Tottori University, Tottori, Japan
- Chromosome Engineering Research Center, Tottori University, Tottori, Japan
| | - Mitsuo Oshimura
- Chromosome Engineering Research Center, Tottori University, Tottori, Japan
| | - Takahiko Hara
- Stem Cell Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
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62
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New perspectives on rare connective tissue calcifying diseases. Curr Opin Pharmacol 2016; 28:14-23. [DOI: 10.1016/j.coph.2016.02.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 01/27/2016] [Accepted: 02/08/2016] [Indexed: 12/27/2022]
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63
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XPR1 mutations are a rare cause of primary familial brain calcification. J Neurol 2016; 263:1559-64. [PMID: 27230854 DOI: 10.1007/s00415-016-8166-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 05/10/2016] [Accepted: 05/10/2016] [Indexed: 12/17/2022]
Abstract
Mutations in XPR1, a gene encoding an inorganic phosphate exporter, have recently been identified in patients with primary familial brain calcification (PFBC). Using Sanger sequencing, we screened XPR1 in 18 unrelated patients with PFBC and no SLC20A2, PDGFB, or PDGFRB mutation. XPR1 variants were tested in an in vitro physiological complementation assay and patient blood cells were assessed ex vivo for phosphate export. We identified a novel c.260T > C, p.(Leu87Pro) XPR1 variant in a 41-year-old man complaining of micrographia and dysarthria and demonstrating mild parkinsonism, cerebellar ataxia and executive dysfunction. Brain (123)I-Ioflupane scintigraphy showed marked dopaminergic neuron loss. Peripheral blood cells from the patient exhibited decreased phosphate export. XPR1 in which we introduced the mutation was not detectable at the cell surface and did not lead to phosphate export. These results confirm that loss of XPR1-mediated phosphate export function causes PFBC, occurring in less than 8 % of cases negative for the other genes, and may be responsible for parkinsonism.
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64
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Keasey MP, Lemos RR, Hagg T, Oliveira JRM. Vitamin-D receptor agonist calcitriol reduces calcification in vitro through selective upregulation of SLC20A2 but not SLC20A1 or XPR1. Sci Rep 2016; 6:25802. [PMID: 27184385 PMCID: PMC4868979 DOI: 10.1038/srep25802] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 04/21/2016] [Indexed: 01/30/2023] Open
Abstract
Vitamin D deficiency (hypovitaminosis D) causes osteomalacia and poor long bone mineralization. In apparent contrast, hypovitaminosis D has been reported in patients with primary brain calcifications (“Fahr’s disease”). We evaluated the expression of two phosphate transporters which we have found to be associated with primary brain calcification (SLC20A2, whose promoter has a predicted vitamin D receptor binding site, and XPR1), and one unassociated (SLC20A1), in an in vitro model of calcification. Expression of all three genes was significantly decreased in calcifying human bone osteosarcoma (SaOs-2) cells. Further, we confirmed that vitamin D (calcitriol) reduced calcification as measured by Alizarin Red staining. Cells incubated with calcitriol under calcifying conditions specifically maintained expression of the phosphate transporter SLC20A2 at higher levels relative to controls, by RT-qPCR. Neither SLC20A1 nor XPR1 were affected by calcitriol treatment and remained suppressed. Critically, knockdown of SLC20A2 gene and protein with CRISPR technology in SaOs2 cells significantly ablated vitamin D mediated inhibition of calcification. This study elucidates the mechanistic importance of SLC20A2 in suppressing the calcification process. It also suggests that vitamin D might be used to regulate SLC20A2 gene expression, as well as reduce brain calcification which occurs in Fahr’s disease and normal aging.
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Affiliation(s)
- M P Keasey
- Department of Biomedical Sciences - Quillen College of Medicine, East Tennessee State University, Johnson City, USA.,Keizo Asami Laboratory - Federal University of Pernambuco, Recife-PE, Brazil
| | - R R Lemos
- Keizo Asami Laboratory - Federal University of Pernambuco, Recife-PE, Brazil
| | - T Hagg
- Department of Biomedical Sciences - Quillen College of Medicine, East Tennessee State University, Johnson City, USA
| | - J R M Oliveira
- Keizo Asami Laboratory - Federal University of Pernambuco, Recife-PE, Brazil.,Neuropsychiatry Department - Federal University of Pernambuco, Recife-PE, Brazil
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65
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Wallingford MC, Chia JJ, Leaf EM, Borgeia S, Chavkin NW, Sawangmake C, Marro K, Cox TC, Speer MY, Giachelli CM. SLC20A2 Deficiency in Mice Leads to Elevated Phosphate Levels in Cerbrospinal Fluid and Glymphatic Pathway-Associated Arteriolar Calcification, and Recapitulates Human Idiopathic Basal Ganglia Calcification. Brain Pathol 2016; 27:64-76. [PMID: 26822507 DOI: 10.1111/bpa.12362] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 01/12/2016] [Indexed: 12/25/2022] Open
Abstract
Idiopathic basal ganglia calcification is a brain calcification disorder that has been genetically linked to autosomal dominant mutations in the sodium-dependent phosphate co-transporter, SLC20A2. The mechanisms whereby deficiency of Slc20a2 leads to basal ganglion calcification are unknown. In the mouse brain, we found that Slc20a2 was expressed in tissues that produce and/or regulate cerebrospinal fluid, including choroid plexus, ependyma and arteriolar smooth muscle cells. Haploinsufficient Slc20a2 +/- mice developed age-dependent basal ganglia calcification that formed in glymphatic pathway-associated arterioles. Slc20a2 deficiency uncovered phosphate homeostasis dysregulation characterized by abnormally high cerebrospinal fluid phosphate levels and hydrocephalus, in addition to basal ganglia calcification. Slc20a2 siRNA knockdown in smooth muscle cells revealed increased susceptibility to high phosphate-induced calcification. These data suggested that loss of Slc20a2 led to dysregulated phosphate homeostasis and enhanced susceptibility of arteriolar smooth muscle cells to elevated phosphate-induced calcification. Together, dysregulated cerebrospinal fluid phosphate and enhanced smooth muscle cell susceptibility may predispose to glymphatic pathway-associated arteriolar calcification.
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Affiliation(s)
| | - Jia Jun Chia
- Department of Bioengineering, University of Washington, Seattle, WA
| | - Elizabeth M Leaf
- Department of Bioengineering, University of Washington, Seattle, WA
| | - Suhaib Borgeia
- Department of Pediatrics, University of Washington, Seattle, WA.,Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA
| | | | - Chenphop Sawangmake
- Department of Pharmacology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
| | - Ken Marro
- Department of Radiology, University of Washington, Seattle, WA
| | - Timothy C Cox
- Department of Pediatrics, University of Washington, Seattle, WA.,Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA
| | - Mei Y Speer
- Department of Bioengineering, University of Washington, Seattle, WA
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66
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Wallingford MC, Gammill HS, Giachelli CM. Slc20a2 deficiency results in fetal growth restriction and placental calcification associated with thickened basement membranes and novel CD13 and lamininα1 expressing cells. Reprod Biol 2016; 16:13-26. [PMID: 26952749 DOI: 10.1016/j.repbio.2015.12.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 12/28/2015] [Accepted: 12/29/2015] [Indexed: 10/22/2022]
Abstract
The essential nutrient phosphorus must be taken up by the mammalian embryo during gestation. The mechanism(s) and key proteins responsible for maternal to fetal phosphate transport have not been identified. Established parameters for placental phosphate transport match those of the type III phosphate transporters, Slc20a1 and Slc20a2. Both members are expressed in human placenta, and their altered expression is linked to preeclampsia. In this study, we tested the hypothesis that Slc20a2 is required for placental function. Indeed, complete deficiency of Slc20a2 in either the maternal or embryonic placental compartment results in fetal growth restriction. We found that Slc20a2 null mice can reproduce, but are subviable; ∼50% are lost prior to weaning age. We also observed that 23% of Slc20a2 deficient females develop pregnancy complications at full term, with tremors and placental abnormalities including abnormal vascular structure, increased basement membrane deposition, abundant calcification, and accumulation of novel CD13 and lamininα1 positive cells. Together these data support that Slc20a2 deficiency impacts both maternal and neonatal health, and Slc20a2 is required for normal placental function. In humans, decreased levels of placental Slc20a1 and Slc20a2 have been correlated with early onset preeclampsia, a disorder that can manifest from placental dysfunction. In addition, preterm placental calcification has been associated with poor pregnancy outcomes. We surveyed placental calcification in human preeclamptic placenta samples, and detected basement membrane-associated placental calcification as well as a comparable lamininα1 positive cell type, indicating that similar mechanisms may underlie both human and mouse placental calcification.
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Affiliation(s)
- Mary C Wallingford
- University of Washington, Department of Bioengineering, 3720 15th Ave NE, Seattle, WA 98195, USA.
| | - Hilary S Gammill
- University of Washington, Department of Obstetrics and Gynecology, Seattle, WA 98195, USA.
| | - Cecilia M Giachelli
- University of Washington, Department of Bioengineering, 3720 15th Ave NE, Seattle, WA 98195, USA.
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67
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Jensen N, Autzen JK, Pedersen L. Slc20a2 is critical for maintaining a physiologic inorganic phosphate level in cerebrospinal fluid. Neurogenetics 2015; 17:125-30. [PMID: 26660102 PMCID: PMC4794525 DOI: 10.1007/s10048-015-0469-6] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2015] [Accepted: 11/29/2015] [Indexed: 12/17/2022]
Abstract
Mutations in the SLC20A2-gene encoding the inorganic phosphate (Pi) transporter PiT2 can explain approximately 40 % of the familial cases of the rare neurodegenerative disorder primary familial brain calcification (Fahr’s disease). The disease characteristic, cerebrovascular-associated calcifications, is also present in Slc20a2-knockout (KO) mice. Little is known about the specific role(s) of PiT2 in the brain. Recent in vitro studies, however, suggest a role in regulation of the [Pi] in cerebrospinal fluid (CSF). We here show that Slc20a2-KO mice indeed have a high CSF [Pi] in agreement with a role of PiT2 in Pi export from the CSF. The implications in relation to disease mechanism are discussed.
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Affiliation(s)
- Nina Jensen
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Department of Molecular Biology and Genetics, Aarhus University, C. F. Møllers Allé 3, Building 1130, 8000, Aarhus, Denmark
| | - Jacob Kwasi Autzen
- Department of Molecular Biology and Genetics, Aarhus University, C. F. Møllers Allé 3, Building 1130, 8000, Aarhus, Denmark
| | - Lene Pedersen
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark. .,Department of Molecular Biology and Genetics, Aarhus University, C. F. Møllers Allé 3, Building 1130, 8000, Aarhus, Denmark.
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68
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Kimura T, Miura T, Aoki K, Saito S, Hondo H, Konno T, Uchiyama A, Ikeuchi T, Takahashi H, Kakita A. Familial idiopathic basal ganglia calcification: Histopathologic features of an autopsied patient with an SLC20A2 mutation. Neuropathology 2015; 36:365-71. [PMID: 26635128 DOI: 10.1111/neup.12280] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Revised: 11/10/2015] [Accepted: 11/10/2015] [Indexed: 12/17/2022]
Abstract
Idiopathic basal ganglia calcification (IBGC), or Fahr's disease, is a neurological disorder characterized by widespread calcification in the brain. Recently, several causative genes have been identified, but the histopathologic features of the brain lesions and expression of the gene products remain unclear. Here, we report the clinical and autopsy features of a 62-year-old Japanese man with familial IBGC, in whom an SLC20A2 mutation was identified. The patient developed mild cognitive impairment and parkinsonism. A brain CT scan demonstrated abnormal calcification in the bilateral basal ganglia, thalami and cerebellum. An MRI study at this point revealed glioblastoma, and the patient died 6 months later. At autopsy, symmetric calcification in the basal ganglia, thalami, cerebellar white matter and deeper layers of the cerebral cortex was evident. The calcification was observed in the tunica media of small arteries, arterioles and capillaries, but not in veins. Immunohistochemistry using an antibody against type III sodium-dependent phosphate transporter 2 (PiT-2), the SLC20A2 product, demonstrated that astrocytic processes were labeled in several regions in control brains, whereas in the patient, reactivity in astrocytes was apparently weak. Immunoblotting demonstrated a marked decrease of PiT-2 in the patient. There are few autopsy reports of IBGC patients with confirmation of the genetic background. The autopsy features seem informative for better understanding the histogenesis of IBGC lesions.
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Affiliation(s)
- Tadashi Kimura
- Departments of Pathology, Brain Research Institute, University of Niigata, Niigata, Japan
| | - Takeshi Miura
- Departments of Neurology, Brain Research Institute, University of Niigata, Niigata, Japan.,Departments of Neurology, Toyama Prefectural Central Hospital, Toyama, Japan
| | - Kenju Aoki
- Departments of Neurology, Toyama Prefectural Central Hospital, Toyama, Japan
| | - Shoji Saito
- Departments of Neurosurgery, Toyama Prefectural Central Hospital, Toyama, Japan
| | - Hiroaki Hondo
- Departments of Neurosurgery, Toyama Prefectural Central Hospital, Toyama, Japan
| | - Takuya Konno
- Departments of Neurology, Brain Research Institute, University of Niigata, Niigata, Japan
| | - Akio Uchiyama
- Departments of Pathology, Toyama Prefectural Central Hospital, Toyama, Japan
| | - Takeshi Ikeuchi
- Departments of Molecular Genetics, Brain Research Institute, University of Niigata, Niigata, Japan
| | - Hitoshi Takahashi
- Departments of Pathology, Brain Research Institute, University of Niigata, Niigata, Japan
| | - Akiyoshi Kakita
- Departments of Pathology, Brain Research Institute, University of Niigata, Niigata, Japan
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69
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Villa-Bellosta R. Vascular Calcification Revisited: A New Perspective for Phosphate Transport. Curr Cardiol Rev 2015; 11:341-351. [PMID: 26242187 PMCID: PMC4774640 DOI: 10.2174/1573403x11666150805120505] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 03/10/2015] [Accepted: 03/11/2015] [Indexed: 12/30/2022] Open
Abstract
Elevated serum phosphorus has emerged as a key risk factor for pathologic calcification of
cardiovascular structures, or vascular calcification (VC). To prevent the formation of calciumphosphate
deposits (CPD), the body uses adenosine-5’-triphosphate (ATP) to synthesize inhibitors of
calcification, including proteins and inhibitors of low molecular weight. Extracellular pyrophosphate
(PPi) is a potent inhibitor of VC, which is produced during extracellular hydrolysis of ATP. Loss of
function in the enzymes and transporters that are involved in the cycle of extracellular ATP, including
Pi transporters, leads to excessive deposition of calcium-phosphate salts. Treatment of hyperphosphatemia
with Pi-binders and Injection of exogenous PPi are the effective treatments to prevent CPD
in the aortic wall. The role of sodium phosphate cotransporters in ectopic calcification is contradictory and not well defined,
but their important role in the control of intracellular Pi levels and the synthesis of ATP make them an important
target to study.
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70
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Nicolas G, Charbonnier C, de Lemos RR, Richard AC, Guillin O, Wallon D, Legati A, Geschwind D, Coppola G, Frebourg T, Campion D, de Oliveira JRM, Hannequin D. Brain calcification process and phenotypes according to age and sex: Lessons from SLC20A2, PDGFB, and PDGFRB mutation carriers. Am J Med Genet B Neuropsychiatr Genet 2015; 168:586-94. [PMID: 26129893 DOI: 10.1002/ajmg.b.32336] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 06/16/2015] [Indexed: 12/17/2022]
Abstract
Primary Familial Brain Calcification (PFBC) is a dominantly inherited cerebral microvascular calcifying disorder with diverse neuropsychiatric expression. Three causative genes have been identified: SLC20A2, PDGFRB and, recently, PDGFB, whose associated phenotype has not yet been extensively studied. We included in the largest published case series of genetically confirmed PFBC, 19 PDGFB (including three new mutations), 24 SLC20A2 (including 4 new mutations), and 14 PDGFRB mutation carriers, from two countries (France and Brazil). We studied clinical features and applied our visual rating scale on all 49 available CT scans. Among the symptomatic mutation carriers (33/57, 58%), the three most frequently observed categories of clinical features were psychiatric signs (72.7%, 76.5%, and 80% for PDGFB, SLC20A2, and PDGFRB, respectively), movement disorders (45.5%, 76.5%, and 40%), and cognitive impairment (54.6%, 64.7%, and 40%). The median age of clinical onset was 31 years, 25% had an early onset (before 18) and 25% a later onset (after 53). Patients with an early clinical onset exhibited mostly isolated psychiatric or cognitive signs, while patients with a later onset exhibited mostly movement disorders, especially in association with other clinical features. CT scans rating allowed identifying four patterns of calcification. The total calcification score was best predicted by the combined effects of gene (SLC20A2 > PDGFB > PDGFRB mutations), sex (male), and (increasing) age, defining three risk classes, which correlated with the four patterns of calcification. These calcification patterns could reflect the natural history of the calcifying process, with distinct risk classes characterized by different age at onset or rate of progression.
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Affiliation(s)
- Gaël Nicolas
- Department of Genetics, Rouen University Hospital, Rouen, France.,CNR-MAJ, Rouen University Hospital, Rouen, France.,Inserm U1079, IRIB, Normandy University, Rouen, France
| | - Camille Charbonnier
- CNR-MAJ, Rouen University Hospital, Rouen, France.,Inserm U1079, IRIB, Normandy University, Rouen, France
| | | | | | - Olivier Guillin
- Inserm U1079, IRIB, Normandy University, Rouen, France.,University Department, Rouvray Psychiatric Hospital and Rouen University Hospital, Sotteville-lès-Rouen, France
| | - David Wallon
- CNR-MAJ, Rouen University Hospital, Rouen, France.,Inserm U1079, IRIB, Normandy University, Rouen, France.,Department of Neurology, Rouen University Hospital, Rouen, France
| | - Andrea Legati
- Department of Psychiatry, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - Daniel Geschwind
- Department of Psychiatry, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA.,Deparment of Neurology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - Giovanni Coppola
- Department of Psychiatry, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA.,Deparment of Neurology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - Thierry Frebourg
- Department of Genetics, Rouen University Hospital, Rouen, France.,Inserm U1079, IRIB, Normandy University, Rouen, France
| | - Dominique Campion
- CNR-MAJ, Rouen University Hospital, Rouen, France.,Inserm U1079, IRIB, Normandy University, Rouen, France.,Department of Research, Rouvray Psychiatric Hospital, Sotteville-lès-Rouen, France
| | - João Ricardo Mendes de Oliveira
- Keizo Asami Laboratory (LIKA), Universidade Federal de Pernambuco (UFPE), Recife, Brazil.,Neuropsychiatry Department, Universidade Federal de Pernambuco, Recife, Brazil
| | - Didier Hannequin
- Department of Genetics, Rouen University Hospital, Rouen, France.,CNR-MAJ, Rouen University Hospital, Rouen, France.,Inserm U1079, IRIB, Normandy University, Rouen, France.,Department of Neurology, Rouen University Hospital, Rouen, France
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71
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Betsholtz C, Keller A. PDGF, pericytes and the pathogenesis of idiopathic basal ganglia calcification (IBGC). Brain Pathol 2015; 24:387-95. [PMID: 24946076 DOI: 10.1111/bpa.12158] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 05/13/2014] [Indexed: 01/09/2023] Open
Abstract
Platelet-derived growth factors (PDGFs) are important mitogens for various types of mesenchymal cells, and as such, they exert critical functions during organogenesis in mammalian embryonic and early postnatal development. Increased or ectopic PDGF activity may also cause or contribute to diseases such as cancer and tissue fibrosis. Until recently, no loss-of-function (LOF) mutations in PDGF or PDGF receptor genes were reported as causally linked to a human disease. This changed in 2013 when reports appeared on presumed LOF mutations in the genes encoding PDGF-B and its receptor PDGF receptor-beta (PDGF-Rβ) in familial idiopathic basal ganglia calcification (IBGC), a brain disease characterized by anatomically localized calcifications in or near the blood microvessels. Here, we review PDGF-B and PDGF-Rβ biology with special reference to their functions in brain-blood vessel development, pericyte recruitment and the regulation of the blood-brain barrier. We also discuss various scenarios for IBGC pathogenesis suggested by observations in patients and genetically engineered animal models of the disease.
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Affiliation(s)
- Christer Betsholtz
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
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72
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Deng H, Zheng W, Jankovic J. Genetics and molecular biology of brain calcification. Ageing Res Rev 2015; 22:20-38. [PMID: 25906927 DOI: 10.1016/j.arr.2015.04.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Revised: 04/14/2015] [Accepted: 04/15/2015] [Indexed: 01/01/2023]
Abstract
Brain calcification is a common neuroimaging finding in patients with neurological, metabolic, or developmental disorders, mitochondrial diseases, infectious diseases, traumatic or toxic history, as well as in otherwise normal older people. Patients with brain calcification may exhibit movement disorders, seizures, cognitive impairment, and a variety of other neurologic and psychiatric symptoms. Brain calcification may also present as a single, isolated neuroimaging finding. When no specific cause is evident, a genetic etiology should be considered. The aim of the review is to highlight clinical disorders associated with brain calcification and provide summary of current knowledge of diagnosis, genetics, and pathogenesis of brain calcification.
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Affiliation(s)
- Hao Deng
- Department of Neurology, Third Xiangya Hospital, Central South University, Changsha, China; Center for Experimental Medicine, Third Xiangya Hospital, Central South University, Changsha, China.
| | - Wen Zheng
- Department of Neurology, Third Xiangya Hospital, Central South University, Changsha, China; Center for Experimental Medicine, Third Xiangya Hospital, Central South University, Changsha, China
| | - Joseph Jankovic
- Department of Neurology, Baylor College of Medicine, Houston, TX, USA
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73
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Gagliardi M, Morelli M, Annesi G, Nicoletti G, Perrotta P, Pustorino G, Iannello G, Tarantino P, Gambardella A, Quattrone A. A new SLC20A2 mutation identified in southern Italy family with primary familial brain calcification. Gene 2015; 568:109-11. [PMID: 25958344 DOI: 10.1016/j.gene.2015.05.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Revised: 05/04/2015] [Accepted: 05/05/2015] [Indexed: 12/17/2022]
Abstract
BACKGROUND Primary familial brain calcification (PFBC) is a rare neurodegenerative disease characterized by bilateral calcifications mostly located in the basal ganglia and in the thalami, cerebellum and subcortical white matter. Clinical manifestations of this disease include a large spectrum of movement disorders and neuropsychiatric disturbances. PFBC is genetically heterogeneous and typically transmitted in an autosomal dominant fashion. Three causative genes have been reported: SLC20A2, PDGFRB and PDGFB. OBJECTIVE We screened three PFBC Italian families for mutations in the SLC20A2, PDGFRB and PDGFB genes. METHODS Phenotypic data were obtained by neurologic examination, CT scan and magnetic resonance imaging. Mutation screening of SLC20A2, PDGFRB and PDGFB was performed by sequencing. RESULTS We identified a new heterozygous deletion c.21_21delG (p.L7Ffs*10) in SLC20A2 gene in one of these families. No mutations were detected in the other two families. CONCLUSIONS Our data confirm that mutations in SLC20A2 are a major cause of familial idiopathic basal ganglia calcification.
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Affiliation(s)
- Monica Gagliardi
- Institute of Molecular Bioimaging and Physiology, National Research Council, Section of Germaneto, Catanzaro, Italy.
| | - Maurizio Morelli
- Institute of Neurology, Department of Medical and Surgical Sciences, University Magna Graecia, Catanzaro, Italy
| | - Grazia Annesi
- Institute of Molecular Bioimaging and Physiology, National Research Council, Section of Germaneto, Catanzaro, Italy
| | - Giuseppe Nicoletti
- Institute of Molecular Bioimaging and Physiology, National Research Council, Section of Germaneto, Catanzaro, Italy
| | - Paolo Perrotta
- Institute of Molecular Bioimaging and Physiology, National Research Council, Section of Germaneto, Catanzaro, Italy
| | - Giuseppe Pustorino
- Institute of Neurology, Department of Medical and Surgical Sciences, University Magna Graecia, Catanzaro, Italy
| | - Grazia Iannello
- Institute of Molecular Bioimaging and Physiology, National Research Council, Section of Germaneto, Catanzaro, Italy; Institute of Neurology, Department of Medical and Surgical Sciences, University Magna Graecia, Catanzaro, Italy
| | - Patrizia Tarantino
- Institute of Molecular Bioimaging and Physiology, National Research Council, Section of Germaneto, Catanzaro, Italy
| | - Antonio Gambardella
- Institute of Molecular Bioimaging and Physiology, National Research Council, Section of Germaneto, Catanzaro, Italy
| | - Aldo Quattrone
- Institute of Molecular Bioimaging and Physiology, National Research Council, Section of Germaneto, Catanzaro, Italy; Institute of Neurology, Department of Medical and Surgical Sciences, University Magna Graecia, Catanzaro, Italy
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74
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Sodium-dependent phosphate transporters in osteoclast differentiation and function. PLoS One 2015; 10:e0125104. [PMID: 25910236 PMCID: PMC4409223 DOI: 10.1371/journal.pone.0125104] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 03/20/2015] [Indexed: 11/19/2022] Open
Abstract
Osteoclasts are multinucleated bone degrading cells. Phosphate is an important constituent of mineralized bone and released in significant quantities during bone resorption. Molecular contributors to phosphate transport during the resorptive activity of osteoclasts have been controversially discussed. This study aimed at deciphering the role of sodium-dependent phosphate transporters during osteoclast differentiation and bone resorption. Our studies reveal RANKL-induced differential expression of sodium-dependent phosphate transport protein IIa (NaPi-IIa) transcript and protein during osteoclast development, but no expression of the closely related NaPi-IIb and NaPi-IIc SLC34 family isoforms. In vitro studies employing NaPi-IIa-deficient osteoclast precursors and mature osteoclasts reveal that NaPi-IIa is dispensable for bone resorption and osteoclast differentiation. These results are supported by the analysis of structural bone parameters by high-resolution microcomputed tomography that yielded no differences between adult NaPi-IIa WT and KO mice. By contrast, both type III sodium-dependent phosphate transporters Pit-1 and Pit-2 were abundantly expressed throughout osteoclast differentiation, indicating that they are the relevant sodium-dependent phosphate transporters in osteoclasts and osteoclast precursors. We conclude that phosphate transporters of the SLC34 family have no role in osteoclast differentiation and function and propose that Pit-dependent phosphate transport could be pivotal for bone resorption and should be addressed in further studies.
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75
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Abstract
Bilateral accumulation of calcium in the brain, most commonly in the basal ganglia, but also in the cerebellum, thalamus, and brainstem can be inherited in an autosomal dominant fashion and is then referred to as primary familial brain calcifications (PFBC). Clinical manifestations include a spectrum of movement disorders and neuropsychiatric abnormalities. In the past 2 years, 3 genes have been identified to cause PFBC, (ie, SLC20A2, PDGFRB, and PDGFB). SCL20A2 encodes the Type III sodium-dependent inorganic phosphate (Pi) transporter 2 (PiT2) and, when mutated, uptake of Pi is severely impaired likely causing buildup of calcium phosphate. The second identified cause of PFBC is mutations in PDGFRB, which codes for platelet-derived growth factor receptor β (PDGF-Rβ). Interestingly, the third PFBC gene is PDGFB that encodes the ligand of PDGF-Rβ, which is secreted during angiogenesis to recruit pericytes, thereby implying impairment of the blood-brain barrier as a disease mechanism of PFBC.
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Affiliation(s)
- Ana Westenberger
- Institute of Neurogenetics, University of Lübeck, Ratzeburger Allee 160, Lübeck, 23538, Germany
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Lemos RR, Ramos EM, Legati A, Nicolas G, Jenkinson EM, Livingston JH, Crow YJ, Campion D, Coppola G, Oliveira JRM. Update and Mutational Analysis of SLC20A2: A Major Cause of Primary Familial Brain Calcification. Hum Mutat 2015; 36:489-95. [PMID: 25726928 DOI: 10.1002/humu.22778] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 02/13/2015] [Indexed: 01/14/2023]
Abstract
Primary familial brain calcification (PFBC) is a heterogeneous neuropsychiatric disorder, with affected individuals presenting a wide variety of motor and cognitive impairments, such as migraine, parkinsonism, psychosis, dementia, and mood swings. Calcifications are usually symmetrical, bilateral, and found predominantly in the basal ganglia, thalamus, and cerebellum. So far, variants in three genes have been linked to PFBC: SLC20A2, PDGFRB, and PDGFB. Variants in SLC20A2 are responsible for most cases identified so far and, therefore, the present review is a comprehensive worldwide summary of all reported variants to date. SLC20A2 encodes an inorganic phosphate transporter, PiT-2, widely expressed in various tissues, including brain, and is part of a major family of solute carrier membrane transporters. Fifty variants reported in 55 unrelated patients so far have been identified in families of diverse ethnicities and only few are recurrent. Various types of variants were detected (missense, nonsense, frameshift) including full or partial SLC20A2 deletions. The recently reported SLC20A2 knockout mouse will enhance our understanding of disease mechanism and allow for screening of therapeutic compounds. In the present review, we also discuss the implications of these recent exciting findings and consider the possibility of treatments based on manipulation of inorganic phosphate homeostasis.
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Affiliation(s)
- Roberta R Lemos
- Keizo Asami Laboratory (LIKA), Universidade Federal de Pernambuco (UFPE), Recife, Brazil
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77
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Taglia I, Bonifati V, Mignarri A, Dotti MT, Federico A. Primary familial brain calcification: update on molecular genetics. Neurol Sci 2015; 36:787-94. [PMID: 25686613 DOI: 10.1007/s10072-015-2110-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 02/10/2015] [Indexed: 12/17/2022]
Abstract
Primary familial brain calcification is a neuropsychiatric disorder with calcium deposits in the brain, especially in basal ganglia, cerebellum and subcortical white matter. The disease is characterized by a clinical heterogeneity, with a various combination of symptoms that include movement disorders and psychiatric disturbances; asymptomatic patients have been also reported. To date, three causative genes have been found: SLC20A2, PDGFRB and PDGFB. SLC20A2 gene codes for the 'sodium-dependent phosphate transporter 2' (PiT-2), a cell membrane transporters of inorganic phosphate, involved in Pi uptake by cells and maintenance of Pi body levels. Over 40 pathogenic variants of SLC20A2 have been reported, affecting the regulation of Pi homeostasis. It was hypothesized that SLC20A2 mutations cause brain calcification most likely through haploinsufficiency. PDGFRB encodes for the platelet-derived growth factor receptor-β (PDGFRβ), a cell-surface tyrosine-kinase (RTK) receptor that regulates cell proliferation, migration, survival and differentiation. PDGFB encodes for the 'platelet-derived growth factor beta' (PDGFβ), the ligand of PDGFRβ. The loss of function of PDGFRβ and PDGFβ could lead to the impairment of the pericytes function and blood brain barrier integrity, causing vascular and perivascular calcium accumulation. SLC20A2 accounts for about 40 % of familial form and 14 % of sporadic cases, while PDGFRB and PDGFB mutations are likely rare. However, approximately 50 % of patients are not genetically defined and there should be at least another causative gene.
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Affiliation(s)
- Ilaria Taglia
- Department of Medicine, Surgery and Neurosciences, University of Siena, 53100, Siena, Italy,
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78
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Arts FA, Velghe AI, Stevens M, Renauld JC, Essaghir A, Demoulin JB. Idiopathic basal ganglia calcification-associated PDGFRB mutations impair the receptor signalling. J Cell Mol Med 2014; 19:239-48. [PMID: 25292412 PMCID: PMC4288366 DOI: 10.1111/jcmm.12443] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 08/21/2014] [Indexed: 12/17/2022] Open
Abstract
Platelet-derived growth factors (PDGF) bind to two related receptor tyrosine kinases, which are encoded by the PDGFRA and PDGFRB genes. Recently, heterozygous PDGFRB mutations have been described in patients diagnosed with idiopathic basal ganglia calcification (IBGC or Fahr disease), a rare inherited neurological disorder. The goal of the present study was to determine whether these mutations had a positive or negative impact on the PDGFRB activity. We first showed that the E1071V mutant behaved like wild-type PDGFRB and may represent a polymorphism unrelated to IBGC. In contrast, the L658P mutant had no kinase activity and failed to activate any of the pathways normally stimulated by PDGF. The R987W mutant activated Akt and MAP kinases but did not induce the phosphorylation of signal transducer and activator of transcription 3 (STAT3) after PDGF stimulation. Phosphorylation of phospholipase Cγ was also decreased. Finally, we showed that the R987W mutant was more rapidly degraded upon PDGF binding compared to wild-type PDGFRB. In conclusion, PDGFRB mutations associated with IBGC impair the receptor signalling. PDGFRB loss of function in IBGC is consistent with recently described inactivating mutations in the PDGF-B ligand. These results raise concerns about the long-term safety of PDGF receptor inhibition by drugs such as imatinib.
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Affiliation(s)
- Florence A Arts
- De Duve Institute, Université catholique de Louvain, Brussels, Belgium
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79
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Kongsfelt IB, Byskov K, Pedersen LE, Pedersen L. High levels of the type III inorganic phosphate transporter PiT1 (SLC20A1) can confer faster cell adhesion. Exp Cell Res 2014; 326:57-67. [PMID: 24880124 DOI: 10.1016/j.yexcr.2014.05.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2013] [Revised: 05/18/2014] [Accepted: 05/20/2014] [Indexed: 01/16/2023]
Abstract
The inorganic phosphate transporter PiT1 (SLC20A1) is ubiquitously expressed in mammalian cells. We recently showed that overexpression of human PiT1 was sufficient to increase proliferation of two strict density-inhibited cell lines, murine fibroblastic NIH3T3 and pre-osteoblastic MC3T3-E1 cells, and allowed the cultures to grow to higher cell densities. In addition, upon transformation NIH3T3 cells showed increased ability to form colonies in soft agar. The cellular regulation of PiT1 expression supports that cells utilize the PiT1 levels to control proliferation, with non-proliferating cells showing the lowest PiT1 mRNA levels. The mechanism behind the role of PiT1 in increased cell proliferation is not known. We, however, found that compared to control cells, cultures of NIH3T3 cells overexpressing PiT1 upon seeding showed increased cell number after 24h and had shifted more cells from G0/G1 to S+G2/M within 12h, suggesting that an early event may play a role. We here show that expression of human PiT1 in NIH3T3 cells led to faster cell adhesion; this effect was not cell type specific in that it was also observed when expressing human PiT1 in MC3T3-E1 cells. We also show for NIH3T3 that PiT1 overexpression led to faster cell spreading. The final total numbers of attached cells did, however, not differ between cultures of PiT1 overexpressing cells and control cells of neither cell type. We suggest that the PiT1-mediated fast adhesion potentials allow the cells to go faster out of G0/G1 and thereby contribute to their proliferative advantage within the first 24h after seeding.
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Affiliation(s)
| | - Kristina Byskov
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark; Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | | | - Lene Pedersen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark; Department of Clinical Medicine, Aarhus University, Aarhus, Denmark; Department of Hematology, Aarhus University Hospital, Aarhus, Denmark.
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80
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PDGFB partial deletion: a new, rare mechanism causing brain calcification with leukoencephalopathy. J Mol Neurosci 2014; 53:171-5. [PMID: 24604296 DOI: 10.1007/s12031-014-0265-z] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2014] [Accepted: 02/13/2014] [Indexed: 12/17/2022]
Abstract
Idiopathic basal ganglia calcification (IBGC) is a progressive cerebral disorder with diverse motor, cognitive, and psychiatric expression. It is inherited as an autosomal dominant trait. Three IBGC-causing genes have been identified in the past 2 years: SLC20A2, PDGFRB, and PDGFB. Biological and genetic evidence showed that loss of function of either SLC20A2 or the PDGFB/PDGFRB pathway was the mechanism underlying calcification in patients with a mutation. Recently, in a study focusing on SLC20A2, a large deletion at this locus was reported. No study has systematically searched for copy number variants (CNV) involving these three genes. We designed a quantitative PCR assay of multiple short fluorescent fragments (QMPSF) to detect CNVs involving one of these three genes in a single assay. Among the 27 unrelated patients from our IBGC case series with no mutation in SLC20A2, PDGFRB, and PDGFB, we identified in one patient a heterozygous partial deletion involving exons 2 to 5 of PDGFB. This patient exhibited both strio-pallido-dentate calcification and white matter hyperintensity of presumed vascular origin, associated with mood disorder, subtle cognitive decline, and gait disorder. We confirmed by RT-PCR experiments that the allele carrying the deletion was transcribed. The resulting cDNA lacks sequence for several critical functional domains of the protein. Intragenic deletion of PDGFB is a new and rare mechanism causing IBGC. CNVs involving the three IBGC-causing genes should be investigated in patients with no point mutation.
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Lemos RR, Ferreira J, Keasey MP, Oliveira JR. An Update on Primary Familial Brain Calcification. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2013; 110:349-71. [DOI: 10.1016/b978-0-12-410502-7.00015-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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