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Sehgal A, Milman T, Li Q, Pulido JS. Histological Findings in the Eyes of Abcc6 Knockout Rat Model of Pseudoxanthoma Elasticum. Transl Vis Sci Technol 2024; 13:29. [PMID: 38656313 PMCID: PMC11044839 DOI: 10.1167/tvst.13.4.29] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Accepted: 02/07/2024] [Indexed: 04/26/2024] Open
Abstract
Purpose To describe the ocular findings of murine pseudoxanthoma elasticum (PXE) models with ATP-binding cassette subfamily C member 6 (Abcc6) gene knockout. Methods This experiment was conducted in four Abcc6-/- rats and compared with six wild-type Abcc6+/+ control rats. The animals underwent necropsy at 6 months of age. Histological examination of the eyes was performed. Results Histological examination of eight eyes from four Abcc6-/- rats revealed multiple nodular foci of calcification in the uvea, sclera, and conjunctiva, focally in perivascular distribution, as well as linear and nodular calcification of Bruch's membrane. Calcific foci were not associated with inflammation in the knockout rats. There was no evidence of calcification in control eyes. Discussion The Abcc6-/- rat model shows that PXE can affect multiple ocular tissues beyond the calcification in Bruch's membrane noted in human eyes. Nodular calcific foci probably correspond to comet lesions seen in patients with PXE. The presence of ectopic calcium without inflammation distinguishes it from inflammatory calcium deposition in atherosclerosis. Further studies are needed to determine why PXE does not cause inflammatory infiltration. Translational Relevance The Abcc6-/- murine model may be suitable for studying ocular PXE pathophysiology and ectopic calcification and developing effective therapies.
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Affiliation(s)
- Anahita Sehgal
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA, USA
| | - Tatyana Milman
- Department of Ophthalmology, Wills Eye Hospital, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, PA, USA
- Department of Pathology, Wills Eye Hospital, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, PA, USA
| | - Qiaoli Li
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA, USA
- PXE International Center of Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, PA, USA
| | - Jose S. Pulido
- Department of Ophthalmology, Wills Eye Hospital, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, PA, USA
- Bower Laboratory for Translational Medicine Vickie and Jack Farber, Vision Research Center at Wills Eye Hospital, Wills Eye Hospital, Philadelphia, PA, USA
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Plümers R, Lindenkamp C, Osterhage MR, Knabbe C, Hendig D. Matrix Metalloproteinases Contribute to the Calcification Phenotype in Pseudoxanthoma Elasticum. Biomolecules 2023; 13:672. [PMID: 37189419 PMCID: PMC10135689 DOI: 10.3390/biom13040672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 03/16/2023] [Accepted: 04/06/2023] [Indexed: 05/17/2023] Open
Abstract
Ectopic calcification and dysregulated extracellular matrix remodeling are prominent hallmarks of the complex heterogenous pathobiochemistry of pseudoxanthoma elasticum (PXE). The disease arises from mutations in ABCC6, an ATP-binding cassette transporter expressed predominantly in the liver. Neither its substrate nor the mechanisms by which it contributes to PXE are completely understood. The fibroblasts isolated from PXE patients and Abcc6-/- mice were subjected to RNA sequencing. A group of matrix metalloproteinases (MMPs) clustering on human chromosome 11q21-23, respectively, murine chromosome 9, was found to be overexpressed. A real-time quantitative polymerase chain reaction, enzyme-linked immunosorbent assay and immunofluorescent staining confirmed these findings. The induction of calcification by CaCl2 resulted in the elevated expression of selected MMPs. On this basis, the influence of the MMP inhibitor Marimastat (BB-2516) on calcification was assessed. PXE fibroblasts (PXEFs) exhibited a pro-calcification phenotype basally. PXEF and normal human dermal fibroblasts responded with calcium deposit accumulation and the induced expression of osteopontin to the addition of Marimastat to the calcifying medium. The raised MMP expression in PXEFs and during cultivation with calcium indicates a correlation of ECM remodeling and ectopic calcification in PXE pathobiochemistry. We assume that MMPs make elastic fibers accessible to controlled, potentially osteopontin-dependent calcium deposition under calcifying conditions.
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Affiliation(s)
| | | | | | | | - Doris Hendig
- Herz- und Diabeteszentrum Nordrhein-Westfalen, Institut für Laboratoriums- und Transfusionsmedizin, Universitätsklinik der Ruhr-Universität Bochum, Georgstraße 11, 32545 Bad Oeynhausen, Germany
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3
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Tiemann J, Lindenkamp C, Wagner T, Brodehl A, Plümers R, Faust-Hinse I, Knabbe C, Hendig D. The Consideration of Pseudoxanthoma Elasticum as a Progeria Syndrome. FRONT BIOSCI-LANDMRK 2023; 28:55. [PMID: 37005749 DOI: 10.31083/j.fbl2803055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 12/01/2022] [Accepted: 12/02/2022] [Indexed: 03/22/2023]
Abstract
BACKGROUND Pseudoxanthoma elasticum (PXE) is a rare autosomal recessive disorder caused by mutations in the ATP-binding cassette sub-family C member 6 (ABCC6) gene. Patients with PXE show molecular and clinical characteristics of known premature aging syndromes, such as Hutchinson-Gilford progeria syndrome (HGPS). Nevertheless, PXE has only barely been discussed against the background of premature aging, although a detailed characterization of aging processes in PXE could contribute to a better understanding of its pathogenesis. Thus, this study was performed to evaluate whether relevant factors which are known to play a role in accelerated aging processes in HGPS pathogenesis are also dysregulated in PXE. METHODS Primary human dermal fibroblasts from healthy donors (n = 3) and PXE patients (n = 3) and were cultivated under different culture conditions as our previous studies point towards effects of nutrient depletion on PXE phenotype. Gene expression of lamin A, lamin C, nucleolin, farnesyltransferase and zinc metallopeptidase STE24 were determined by quantitative real-time polymerase chain reaction. Additionally, protein levels of lamin A, C and nucleolin were evaluated by immunofluorescence and the telomere length was analyzed. RESULTS We could show a significant decrease of lamin A and C gene expression in PXE fibroblasts under nutrient depletion compared to controls. The gene expression of progerin and farnesyltransferase showed a significant increase in PXE fibroblasts when cultivated in 10% fetal calf serum (FCS) compared to controls. Immunofluorescence microscopy of lamin A/C and nucleolin and mRNA expression of zinc metallopeptidase STE24 and nucleolin showed no significant changes in any case. The determination of the relative telomere length showed significantly longer telomeres for PXE fibroblasts compared to controls when cultivated in 10% FCS. CONCLUSIONS These data indicate that PXE fibroblasts possibly undergo a kind of senescence which is independent of telomere damage and not triggered by defects of the nuclear envelope or nucleoli deformation.
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Affiliation(s)
- Janina Tiemann
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, 32545 Bad Oeynhausen, Germany
| | - Christopher Lindenkamp
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, 32545 Bad Oeynhausen, Germany
| | - Thomas Wagner
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, 32545 Bad Oeynhausen, Germany
| | - Andreas Brodehl
- E. & H. Klessmann Institute for Cardiovascular Research & Development, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, 32545 Bad Oeynhausen, Germany
| | - Ricarda Plümers
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, 32545 Bad Oeynhausen, Germany
| | - Isabel Faust-Hinse
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, 32545 Bad Oeynhausen, Germany
| | - Cornelius Knabbe
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, 32545 Bad Oeynhausen, Germany
| | - Doris Hendig
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, 32545 Bad Oeynhausen, Germany
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Morikane S, Ishida K, Taniguchi T, Ashizawa N, Matsubayashi M, Kurita N, Kobashi S, Iwanaga T. Identification of a DBA/2 Mouse Sub-strain as a Model for Pseudoxanthoma Elasticum-Like Tissue Calcification. Biol Pharm Bull 2023; 46:1737-1744. [PMID: 38044132 DOI: 10.1248/bpb.b23-00478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
Ectopic calcification in the cardiovascular system adversely affects life prognosis. DBA/2 mice experience calcification owing to low expression of Abcc6 as observed in pseudoxanthoma elasticum (PXE) patients; however, little is known about its characteristics as a calcification model. In this study, we explore the suitability of a DBA/2 sub-strain as a PXE-like tissue calcification model, and the effect of a bisphosphonate which prevents calcification of soft tissues in hypercalcemic models was evaluated. The incidence of calcification of the heart was compared among several sub-strains and between both sexes of DBA/2 mice. mRNA expression of calcification-related genes was compared with DBA/2 sub-strains and other mouse strains. In addition, progression of calcification and calciprotein particle formation in serum were examined. Among several sub-strains of DBA/2 mice, male DBA/2CrSlc mice showed the most remarkable cardiac calcification. In DBA/2CrSlc mice, expression of the anti-calcifying genes Abcc6, Enpp1 and Spp1 was lower than that in C57BL/6J, and expression of Enpp1 and Spp1 was lower compared with other sub-strains. Calcification was accompanied by accelerated formation of calciprotein particle, which was prevented by daily treatment with bisphosphonate. A model suitable for ectopic calcification was identified by choosing a sub-strain of DBA/2 mice, in which genetic characteristics would contribute to extended calcification.
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Bouderlique E, Tang E, Zaworski J, Coudert A, Bazin D, Borondics F, Haymann JP, Leftheriotis G, Martin L, Daudon M, Letavernier E. Vitamin D and Calcium Supplementation Accelerate Vascular Calcification in a Model of Pseudoxanthoma Elasticum. Int J Mol Sci 2022; 23:ijms23042302. [PMID: 35216422 PMCID: PMC8878394 DOI: 10.3390/ijms23042302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 02/11/2022] [Accepted: 02/17/2022] [Indexed: 11/16/2022] Open
Abstract
Arterial calcification is a common feature of pseudoxanthoma elasticum (PXE), a disease characterized by ABCC6 mutations, inducing a deficiency in pyrophosphate, a key inhibitor of calcium phosphate crystallization in arteries. METHODS we analyzed whether long-term exposure of Abcc6-/- mice (a murine model of PXE) to a mild vitamin D supplementation, with or without calcium, would impact the development of vascular calcification. Eight groups of mice (including Abcc6-/- and wild-type) received vitamin D supplementation every 2 weeks, a calcium-enriched diet alone (calcium in drinking water), both vitamin D supplementation and calcium-enriched diet, or a standard diet (controls) for 6 months. Aorta and kidney artery calcification was assessed by 3D-micro-computed tomography, Optical PhotoThermal IR (OPTIR) spectroscopy, scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS) and Yasue staining. RESULTS at 6 months, although vitamin D and/or calcium did not significantly increase serum calcium levels, vitamin D and calcium supplementation significantly worsened aorta and renal artery calcification in Abcc6-/- mice. CONCLUSIONS vitamin D and/or calcium supplementation accelerate vascular calcification in a murine model of PXE. These results sound a warning regarding the use of these supplementations in PXE patients and, to a larger extent, patients with low systemic pyrophosphate levels.
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Affiliation(s)
- Elise Bouderlique
- UMR S 1155, Sorbonne Université, 75020 Paris, France; (E.B.); (E.T.); (J.Z.); (J.-P.H.); (M.D.)
- Institut National de la Santé et de la Recherche Médicale (INSERM), Sorbonne Université, 75020 Paris, France
| | - Ellie Tang
- UMR S 1155, Sorbonne Université, 75020 Paris, France; (E.B.); (E.T.); (J.Z.); (J.-P.H.); (M.D.)
- Institut National de la Santé et de la Recherche Médicale (INSERM), Sorbonne Université, 75020 Paris, France
| | - Jeremy Zaworski
- UMR S 1155, Sorbonne Université, 75020 Paris, France; (E.B.); (E.T.); (J.Z.); (J.-P.H.); (M.D.)
- Institut National de la Santé et de la Recherche Médicale (INSERM), Sorbonne Université, 75020 Paris, France
| | - Amélie Coudert
- UFR d’odontologie (Département des Sciences Biologiques), Université Paris Diderot BIOSCAR—INSERM U1132, Hôpital Lariboisière, 75010 Paris, France;
| | - Dominique Bazin
- Laboratoire de Physique des Solides, CNRS UMR 8502, Université Paris Sud XI, 91405 Orsay, France;
| | - Ferenc Borondics
- Synchrotron Soleil, L’Orme des Merisiers, Saint-Aubin–BP48, CEDEX, 91192 Gif-sur-Yvette, France;
| | - Jean-Philippe Haymann
- UMR S 1155, Sorbonne Université, 75020 Paris, France; (E.B.); (E.T.); (J.Z.); (J.-P.H.); (M.D.)
- Institut National de la Santé et de la Recherche Médicale (INSERM), Sorbonne Université, 75020 Paris, France
- Physiology Unit, AP-HP, Hôpital Tenon, 75020 Paris, France
| | - Georges Leftheriotis
- Laboratory of Physiology and Molecular Medicine (LP2M), CNRS-UNS UMR 7370, University of Nice, 28 rue de Valombrose, CEDEX 2, 06107 Nice, France;
| | - Ludovic Martin
- MITOVASC Institute—UMR CNRS 6015 INSERM U1083 Angers University, 49100 Angers, France;
- PXE Consultation Center, MAGEC Reference Center, MAGEC Nord Center for Rare Skin Diseases, Angers University Hospital, 49100 Angers, France
| | - Michel Daudon
- UMR S 1155, Sorbonne Université, 75020 Paris, France; (E.B.); (E.T.); (J.Z.); (J.-P.H.); (M.D.)
- Institut National de la Santé et de la Recherche Médicale (INSERM), Sorbonne Université, 75020 Paris, France
- Physiology Unit, AP-HP, Hôpital Tenon, 75020 Paris, France
| | - Emmanuel Letavernier
- UMR S 1155, Sorbonne Université, 75020 Paris, France; (E.B.); (E.T.); (J.Z.); (J.-P.H.); (M.D.)
- Institut National de la Santé et de la Recherche Médicale (INSERM), Sorbonne Université, 75020 Paris, France
- Physiology Unit, AP-HP, Hôpital Tenon, 75020 Paris, France
- Correspondence:
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Bouderlique E, Nollet L, Letavernier E, Vanakker OM. Minocycline Counteracts Ectopic Calcification in a Murine Model of Pseudoxanthoma Elasticum: A Proof-of-Concept Study. Int J Mol Sci 2022; 23:ijms23031838. [PMID: 35163765 PMCID: PMC8837001 DOI: 10.3390/ijms23031838] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 02/01/2022] [Accepted: 02/03/2022] [Indexed: 02/06/2023] Open
Abstract
Pseudoxanthoma elasticum (PXE) is an intractable Mendelian disease characterized by ectopic calcification in skin, eyes and blood vessels. Recently, increased activation of the DNA damage response (DDR) was shown to be involved in PXE pathogenesis, while the DDR/PARP1 inhibitor minocycline was found to attenuate aberrant mineralization in PXE cells and zebrafish. In this proof-of-concept study, we evaluated the anticalcifying properties of minocycline in Abcc6−/− mice, an established mammalian PXE model. Abcc6−/− mice received oral minocycline supplementation (40 mg/kg/day) from 12 to 36 weeks of age and were compared to untreated Abcc6−/− and Abcc6+/+ siblings. Ectopic calcification was evaluated using X-ray microtomography with three-dimensional reconstruction of calcium deposits in muzzle skin and Yasue’s calcium staining. Immunohistochemistry for the key DDR marker H2AX was also performed. Following minocycline treatment, ectopic calcification in Abcc6−/− mice was significantly reduced (−43.4%, p < 0.0001) compared to untreated Abcc6−/− littermates. H2AX immunostaining revealed activation of the DDR at sites of aberrant mineralization in untreated Abcc6−/− animals. In conclusion, we validated the anticalcifying effect of minocycline in Abcc6−/− mice for the first time. Considering its favorable safety profile in humans and low cost as a generic drug, minocycline may be a promising therapeutic compound for PXE patients.
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Affiliation(s)
- Elise Bouderlique
- UMR S 1155, Institut National de la Santé et de la Recherche Médicale (INSERM), Sorbonne Université, 75020 Paris, France; (E.B.); (E.L.)
| | - Lukas Nollet
- Center for Medical Genetics, Ghent University Hospital, 9000 Ghent, Belgium;
- Department of Biomolecular Medicine, Ghent University, 9000 Ghent, Belgium
- Ectopic Mineralization Research Group, 9000 Ghent, Belgium
| | - Emmanuel Letavernier
- UMR S 1155, Institut National de la Santé et de la Recherche Médicale (INSERM), Sorbonne Université, 75020 Paris, France; (E.B.); (E.L.)
| | - Olivier M. Vanakker
- Center for Medical Genetics, Ghent University Hospital, 9000 Ghent, Belgium;
- Department of Biomolecular Medicine, Ghent University, 9000 Ghent, Belgium
- Ectopic Mineralization Research Group, 9000 Ghent, Belgium
- Correspondence:
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Tiemann J, Wagner T, Lindenkamp C, Plümers R, Faust I, Knabbe C, Hendig D. Linking ABCC6 Deficiency in Primary Human Dermal Fibroblasts of PXE Patients to p21-Mediated Premature Cellular Senescence and the Development of a Proinflammatory Secretory Phenotype. Int J Mol Sci 2020; 21:E9665. [PMID: 33352936 PMCID: PMC7766446 DOI: 10.3390/ijms21249665] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 12/16/2020] [Accepted: 12/17/2020] [Indexed: 12/22/2022] Open
Abstract
Pseudoxanthoma elasticum (PXE) is a rare autosomal-recessive disorder that is mainly caused by mutations in the ATP-binding cassette sub-family C member 6 (ABCC6) gene. Clinically PXE is characterized by a loss of skin elasticity, arteriosclerosis or visual impairments. It also shares some molecular characteristics with known premature aging syndromes like the Hutchinson-Gilford progeria syndrome (HGPS). However, little is known about accelerated aging processes, especially on a cellular level for PXE now. Therefore, this study was performed to reveal a potential connection between premature cellular aging and PXE pathogenesis by analyzing cellular senescence, a corresponding secretory phenotype and relevant factors of the cell cycle control in primary human dermal fibroblasts of PXE patients. Here, we could show an increased senescence-associated β-galactosidase (SA-β-Gal) activity as well as an increased expression of proinflammatory factors of a senescence-associated secretory phenotype (SASP) like interleukin 6 (IL6) and monocyte chemoattractant protein-1 (MCP1). We further observed an increased gene expression of the cyclin-dependent kinase inhibitor (CDKI) p21, but no simultaneous induction of p53 gene expression. These data indicate that PXE is associated with premature cellular senescence, which is possibly triggered by a p53-independent p21-mediated mechanism leading to a proinflammatory secretory phenotype.
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Affiliation(s)
| | | | | | | | | | | | - Doris Hendig
- Institut für Laboratoriums-und Transfusionsmedizin, Herz-und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, 32545 Bad Oeynhausen, Germany; (J.T.); (T.W.); (C.L.); (R.P.); (I.F.); (C.K.)
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8
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Abstract
PURPOSE OF REVIEW This review summarizes current understanding of generalized arterial calcification of infancy (GACI), emphasizing pathophysiology, clinical presentation, and approaches and controversies in management. RECENT FINDINGS Identification of causative ENPP1 mutations revealed that GACI arises from deficiencies in inorganic pyrophosphate (leading to calcifications) and adenosine monophosphate (leading to intimal proliferation). Identification of genotypic and phenotypic overlap with pseudoxanthoma elasticum and autosomal recessive hypophosphatemic rickets further advanced understanding of GACI as a complex, multisystemic disease. Clinical data is limited to small, retrospective samples; it is therefore unknown whether commonly used medications, such as bisphosphonates and hypophosphatemia treatment, are therapeutic or potentially harmful. ENPP1-Fc replacement represents a promising approach warranting further study. Knowledge gaps in natural history place clinicians at high risk of assigning causality to interventions that are correlated with changes in clinical status. There is thus a critical need for improved natural history studies to develop and test targeted therapies.
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Affiliation(s)
- Alison M Boyce
- Skeletal Diseases and Mineral Homeostasis Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, 30 Convent Drive Room 218 MSC 4320, Bethesda, MD, 20892, USA.
| | - Rachel I Gafni
- Skeletal Diseases and Mineral Homeostasis Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, 30 Convent Drive Room 218 MSC 4320, Bethesda, MD, 20892, USA
| | - Carlos R Ferreira
- Medical Genomics and Metabolic Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
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Van Gils M, Nollet L, Verly E, Deianova N, Vanakker OM. Cellular signaling in pseudoxanthoma elasticum: an update. Cell Signal 2019; 55:119-129. [PMID: 30615970 DOI: 10.1016/j.cellsig.2018.12.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 12/20/2018] [Accepted: 12/20/2018] [Indexed: 12/27/2022]
Abstract
Pseudoxanthoma elasticum is an autosomal recessive genodermatosis with variable expression, due to mutations in the ABCC6 or ENPP1 gene. It is characterized by elastic fiber mineralization and fragmentation, resulting in skin, eye and cardiovascular symptoms. Significant advances have been made in the last 20 years with respect to the phenotypic characterization and pathophysiological mechanisms leading to elastic fiber mineralization. Nonetheless, the substrates of the ABCC6 transporter - the main cause of PXE - remain currently unknown. Though the precise mechanisms linking the ABCC6 transporter to mineralization of the extracellular matrix are unclear, several studies have looked into the cellular consequences of ABCC6 deficiency in PXE patients and/or animal models. In this paper, we compile the evidence on cellular signaling in PXE, which seems to revolve mainly around TGF-βs, BMPs and inorganic pyrophosphate signaling cascades. Where conflicting results or fragmented data are present, we address these with novel signaling data. This way, we aim to better understand the up- and down-stream signaling of TGF-βs and BMPs in PXE and we demonstrate that ANKH deficiency can be an additional mechanism contributing to decreased serum PPi levels in PXE patients.
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Affiliation(s)
- M Van Gils
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium; Department of Biomolecular Medicine, Ghent University, Belgium
| | - L Nollet
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - E Verly
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - N Deianova
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - O M Vanakker
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium; Department of Biomolecular Medicine, Ghent University, Belgium.
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Moreno JA, Alvarez A, Lorenzo D, Grimalt R. Subtle skin changes that suggest severe disease. BMJ 2018; 361:k1336. [PMID: 29776908 DOI: 10.1136/bmj.k1336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
| | | | | | - Ramon Grimalt
- Universitat Internacional de Catalunya, Barcelona, Spain
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11
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Favre G, Laurain A, Aranyi T, Szeri F, Fulop K, Le Saux O, Duranton C, Kauffenstein G, Martin L, Lefthériotis G. The ABCC6 Transporter: A New Player in Biomineralization. Int J Mol Sci 2017; 18:ijms18091941. [PMID: 28891970 PMCID: PMC5618590 DOI: 10.3390/ijms18091941] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 09/02/2017] [Accepted: 09/05/2017] [Indexed: 12/16/2022] Open
Abstract
Pseudoxanthoma elasticum (PXE) is an inherited metabolic disease with autosomal recessive inheritance caused by mutations in the ABCC6 gene. Since the first description of the disease in 1896, alleging a disease involving the elastic fibers, the concept evolved with the further discoveries of the pivotal role of ectopic mineralization that is preponderant in the elastin-rich tissues of the skin, eyes and blood vessel walls. After discovery of the causative gene of the disease in 2000, the function of the ABCC6 protein remains elusive. More than 300 mutations have been now reported and the concept of a dermal disease has progressively evolved toward a metabolic disorder resulting from the remote effects caused by lack of a circulating anti-mineralization factor. Very recently, evidence has accumulated that this anti-mineralizing factor is inorganic pyrophosphate (PPi). This leads to decreased PPi/Pi (inorganic phosphate) ratio that results from the lack of extracellular ATP release by hepatocytes and probably renal cells harboring the mutant ABCC6 protein. However, the mechanism by which ABCC6 dysfunction causes diminished ATP release remains an enigma. Studies of other ABC transporters, such as ABCC7 or ABCC1 could help our understanding of what ABCC6 exact function is. Data and a hypothesis on the possible roles of ABCC6 in acquired metabolic diseases are also discussed.
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Affiliation(s)
- Guillaume Favre
- FINSERM, U 1081, Aging and Diabetes Team, Institute for Research on Cancer and Aging of Nice (IRCAN), 06107 Nice, France.
- CNRS, UMR7284, Institute for Research on Cancer and Aging of Nice (IRCAN), 06107 Nice, France.
- Faculty of Medicine, University of Nice-Sophia Antipolis, 06107 Nice, France.
- Nephrology Department, University Hospital, 06107 Nice, France.
| | - Audrey Laurain
- Nephrology Department, University Hospital, 06107 Nice, France.
| | - Tamas Aranyi
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, 1117 Budapest, Hungary.
| | - Flora Szeri
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, 1117 Budapest, Hungary.
| | - Krisztina Fulop
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, 1117 Budapest, Hungary.
| | - Olivier Le Saux
- Department Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, Honolulu, HI 96813, USA.
| | - Christophe Duranton
- Laboratory of Physiology and Molecular Medicine (LP2M) UMR CNRS 7073, 06107 Nice, France.
| | - Gilles Kauffenstein
- UMR CNRS 6015-Inserm 1083, School of Medicine, Bretagne Loire University, 49045 Angers, France.
- PXE Health and Research Center, University Hospital of Angers, 49045 Angers, France.
| | - Ludovic Martin
- UMR CNRS 6015-Inserm 1083, School of Medicine, Bretagne Loire University, 49045 Angers, France.
- PXE Health and Research Center, University Hospital of Angers, 49045 Angers, France.
| | - Georges Lefthériotis
- Faculty of Medicine, University of Nice-Sophia Antipolis, 06107 Nice, France.
- Laboratory of Physiology and Molecular Medicine (LP2M) UMR CNRS 7073, 06107 Nice, France.
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12
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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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13
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Abstract
Pseudoxanthoma elasticum (PXE) is a genetic metabolic disease with autosomal recessive inheritance caused by mutations in the ABCC6 gene. The lack of functional ABCC6 protein leads to ectopic mineralization that is most apparent in the elastic tissues of the skin, eyes and blood vessels. The clinical prevalence of PXE has been estimated at between 1 per 100,000 and 1 per 25,000, with slight female predominance. The first clinical sign of PXE is almost always small yellow papules on the nape and sides of the neck and in flexural areas. The papules coalesce, and the skin becomes loose and wrinkled. The mid-dermal elastic fibers are short, fragmented, clumped and calcified. Dystrophic calcification of Bruch's membrane, revealed by angioid streaks, may trigger choroidal neovascularization and, ultimately, loss of central vision and blindness in late-stage disease. Lesions in small and medium-sized artery walls may result in intermittent claudication and peripheral artery disease. Cardiac complications (myocardial infarction, angina pectoris) are thought to be relatively rare but merit thorough investigation. Ischemic strokes have been reported. PXE is a metabolic disease in which circulating levels of an anti-mineralization factor are low. There is good evidence to suggest that the factor is inorganic pyrophosphate (PPi), and that the circulating low levels of PPi and decreased PPi/Pi ratio result from the lack of ATP release by hepatocytes harboring the mutant ABCC6 protein. However, the substrate(s) bound, transported or modulated by the ABCC6 protein remain unknown. More than 300 sequence variants of the ABCC6 gene have been identified. There is no cure for PXE; the main symptomatic treatments are vascular endothelial growth factor inhibitor therapy (for ophthalmic manifestations), lifestyle, lipid-lowering and dietary measures (for reducing vascular risk factors), and vascular surgery (for severe cardiovascular manifestations). Future treatment options may include gene therapy/editing and pharmacologic chaperone therapy.
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Affiliation(s)
- Dominique P Germain
- Division of Medical Genetics, University of Versailles - Saint Quentin en Yvelines, Paris-Saclay University, 2 avenue de la source de la Bièvre, F-78180, Montigny, France.
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14
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Pomozi V, Brampton C, van de Wetering K, Zoll J, Calio B, Pham K, Owens JB, Marh J, Moisyadi S, Váradi A, Martin L, Bauer C, Erdmann J, Aherrahrou Z, Le Saux O. Pyrophosphate Supplementation Prevents Chronic and Acute Calcification in ABCC6-Deficient Mice. Am J Pathol 2017; 187:1258-1272. [PMID: 28416300 DOI: 10.1016/j.ajpath.2017.02.009] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 02/16/2017] [Indexed: 12/28/2022]
Abstract
Soft tissue calcification occurs in several common acquired pathologies, such as diabetes and hypercholesterolemia, or can result from genetic disorders. ABCC6, a transmembrane transporter primarily expressed in liver and kidneys, initiates a molecular pathway inhibiting ectopic calcification. ABCC6 facilitates the cellular efflux of ATP, which is rapidly converted into pyrophosphate (PPi), a major calcification inhibitor. Heritable mutations in ABCC6 underlie the incurable calcification disorder pseudoxanthoma elasticum and some cases of generalized arterial calcification of infancy. Herein, we determined that the administration of PPi and the bisphosphonate etidronate to Abcc6-/- mice fully inhibited the acute dystrophic cardiac calcification phenotype, whereas alendronate had no significant effect. We also found that daily injection of PPi to Abcc6-/- mice over several months prevented the development of pseudoxanthoma elasticum-like spontaneous calcification, but failed to reverse already established lesions. Furthermore, we found that the expression of low amounts of the human ABCC6 in liver of transgenic Abcc6-/- mice, resulting in only a 27% increase in plasma PPi levels, led to a major reduction in acute and chronic calcification phenotypes. This proof-of-concept study shows that the development of both acute and chronic calcification associated with ABCC6 deficiency can be prevented by compensating PPi deficits, even partially. Our work indicates that PPi substitution represents a promising strategy to treat ABCC6-dependent calcification disorders.
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Affiliation(s)
- Viola Pomozi
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii
| | - Christopher Brampton
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii
| | - Koen van de Wetering
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, PXE International Center of Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Janna Zoll
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii
| | - Bianca Calio
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii
| | - Kevin Pham
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii
| | - Jesse B Owens
- Institute for Biogenesis Research, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii
| | - Joel Marh
- Institute for Biogenesis Research, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii
| | - Stefan Moisyadi
- Institute for Biogenesis Research, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii
| | - András Váradi
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Ludovic Martin
- Université Bretagne-Loire, Integrated Neurovascular and Mitochondrial Biology, National Center for Scientific Research 6214/INSERM 1083, Angers, France; University Hospital Angers, Center for PXE Consultation, Angers, France
| | - Carolin Bauer
- Institut für Integrative und Experimentelle Genomik Universität zu Lübeck, German Centre for Cardiovascular Research, Partner Site Hamburg/Kiel/Lübeck, Germany; University Heart Centre Lübeck, Universität zu Lübeck, Lübeck, Germany
| | - Jeanette Erdmann
- Institut für Integrative und Experimentelle Genomik Universität zu Lübeck, German Centre for Cardiovascular Research, Partner Site Hamburg/Kiel/Lübeck, Germany; University Heart Centre Lübeck, Universität zu Lübeck, Lübeck, Germany
| | - Zouhair Aherrahrou
- Institut für Integrative und Experimentelle Genomik Universität zu Lübeck, German Centre for Cardiovascular Research, Partner Site Hamburg/Kiel/Lübeck, Germany; University Heart Centre Lübeck, Universität zu Lübeck, Lübeck, Germany
| | - Olivier Le Saux
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii.
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15
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Kuzaj P, Kuhn J, Michalek RD, Karoly ED, Faust I, Dabisch-Ruthe M, Knabbe C, Hendig D. Large-scaled metabolic profiling of human dermal fibroblasts derived from pseudoxanthoma elasticum patients and healthy controls. PLoS One 2014; 9:e108336. [PMID: 25265166 PMCID: PMC4181624 DOI: 10.1371/journal.pone.0108336] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 08/29/2014] [Indexed: 12/18/2022] Open
Abstract
Mutations in the ABC transporter ABCC6 were recently identified as cause of Pseudoxanthoma elasticum (PXE), a rare genetic disorder characterized by progressive mineralization of elastic fibers. We used an untargeted metabolic approach to identify biochemical differences between human dermal fibroblasts from healthy controls and PXE patients in an attempt to find a link between ABCC6 deficiency, cellular metabolic alterations and disease pathogenesis. 358 compounds were identified by mass spectrometry covering lipids, amino acids, peptides, carbohydrates, nucleotides, vitamins and cofactors, xenobiotics and energy metabolites. We found substantial differences in glycerophospholipid composition, leucine dipeptides, and polypeptides as well as alterations in pantothenate and guanine metabolism to be significantly associated with PXE pathogenesis. These findings can be linked to extracellular matrix remodeling and increased oxidative stress, which reflect characteristic hallmarks of PXE. Our study could facilitate a better understanding of biochemical pathways involved in soft tissue mineralization.
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Affiliation(s)
- Patricia Kuzaj
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany
| | - Joachim Kuhn
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany
| | - Ryan D. Michalek
- Metabolon, Inc., Durham, North Carolina, United States of America
| | - Edward D. Karoly
- Metabolon, Inc., Durham, North Carolina, United States of America
| | - Isabel Faust
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany
| | - Mareike Dabisch-Ruthe
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany
| | - Cornelius Knabbe
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany
| | - Doris Hendig
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany
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16
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Dabisch-Ruthe M, Kuzaj P, Götting C, Knabbe C, Hendig D. Pyrophosphates as a major inhibitor of matrix calcification in Pseudoxanthoma elasticum. J Dermatol Sci 2014; 75:109-20. [PMID: 24907773 DOI: 10.1016/j.jdermsci.2014.04.015] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 04/22/2014] [Accepted: 04/23/2014] [Indexed: 11/18/2022]
Abstract
BACKGROUND Pseudoxanthoma elasticum (PXE) is a rare hereditary disorder characterized by late onset and progressive calcification of elastic fibers in skin, eyes and the cardiovascular system, exemplifying a model for conditions characterized by soft tissue calcification. OBJECTIVE The aim of our study was to characterize cellular inorganic pyrophosphate (PPi) homeostasis in PXE. METHODS Gene expression of PPi metabolizing enzymes was determined by quantitative real-time PCR after incubation up to 21 days with or without addition of Na2HPO4. Extracellular and cytosolic PPi concentrations were measured by enzyme-linked bioluminescence assay. ALP and ENPP1 activity was determined spectrophotometrically. We further established a human cell culture model suitable for investigating PXE and related disorders without addition of artificial calcification triggers. RESULTS Independently of the experimental conditions, PXE fibroblasts revealed a higher degree of matrix calcification. We observed that matrix calcification was associated with altered gene expression of PPi metabolizing enzymes in PXE fibroblasts. In this context, PXE fibroblasts exhibited significantly higher expression of ALP and OPN and reduced mRNA expression and activity of ENPP1. Here, for the first time cytosolic and extracellular PPi levels were shown to be strongly reduced in PXE fibroblasts. We further showed that PPi concentration in bovine and human sera additives had a strong impact on matrix calcification. In a last experimental line, we demonstrated that addition of PPi analogs reduced matrix calcification of PXE fibroblasts most likely by reducing ALP and OPN mRNA expression, restoring ENPP1 activity and subsequently elevating PPi concentrations. CONCLUSION The results of our study along with recent findings point to the essential role of PPi as the central regulatory metabolites preventing matrix calcification in PXE. But what remains to be determined is the underlying molecular mechanism leading to depletion of PPi in PXE. We further suggest that supplementation of PPi analogs might counteract pathological calcification in PXE and related disorders.
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Affiliation(s)
- Mareike Dabisch-Ruthe
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany
| | - Patricia Kuzaj
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany
| | | | - Cornelius Knabbe
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany
| | - Doris Hendig
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany.
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17
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Boraldi F, Annovi G, Bartolomeo A, Quaglino D. Fibroblasts from patients affected by Pseudoxanthoma elasticum exhibit an altered PPi metabolism and are more responsive to pro-calcifying stimuli. J Dermatol Sci 2014; 74:72-80. [PMID: 24461675 DOI: 10.1016/j.jdermsci.2013.12.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 12/13/2013] [Accepted: 12/19/2013] [Indexed: 01/31/2023]
Abstract
BACKGROUND Pseudoxanthoma elasticum (PXE) is a genetic disorder characterized by progressive calcification of soft connective tissues. The pathogenesis is still hard to pin down. In PXE dermal fibroblasts, in addition to impaired carboxylation of the vitamin K-dependent inhibitor matrix Gla protein (MGP), we have also demonstrated an up-regulation of alkaline phosphatase activity. In the light of these data we have suggested that both calcium and phosphate metabolism might be locally altered, both pathways acting in synergy on the occurrence of matrix calcification. OBJECTIVE This study aims to better explore if cultured PXE fibroblasts, compared to control cells, exhibit a modified inorganic pyrophosphate (PPi) metabolism and are more responsive to pro-calcifying stimuli. METHODS Primary human dermal fibroblasts isolated from healthy individuals and from PXE patients were cultured for different time points in standard and in pro-calcifying media. The expression of ANKH/ANKH, ENPP1/PC1, ALPL/TNAP, SPP1/OPN was evaluated by qRT-PCR and Western blot, respectively. TNAP activity was measured by spectrophotometric analyses, whereas calcification was investigated by light and electron microscopy as well as by micro-analytical techniques. RESULTS In the presence of pro-calcifying stimuli, dermal fibroblasts alter their phenotype favouring matrix mineralization. In particular, ENPP1/PC1 and SPP1/OPN expression, as well as TNAP activity, was differently expressed in control and in PXE fibroblasts. Moreover, in pathologic cells the ratio between factors favouring and reducing PPi availability exhibits a more pronounced shift towards a pro-calcifying balance. CONCLUSION PXE fibroblasts are more susceptible to pro-calcifying stimuli and in these cells an altered PPi metabolism contributes to matrix calcification.
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Affiliation(s)
- Federica Boraldi
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Giulia Annovi
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Angelica Bartolomeo
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Daniela Quaglino
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy.
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18
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Boraldi F, Garcia-Fernandez M, Paolinelli-Devincenzi C, Annovi G, Schurgers L, Vermeer C, Cianciulli P, Ronchetti I, Quaglino D. Ectopic calcification in β-thalassemia patients is associated with increased oxidative stress and lower MGP carboxylation. Biochim Biophys Acta 2013; 1832:2077-84. [PMID: 23899606 DOI: 10.1016/j.bbadis.2013.07.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 06/24/2013] [Accepted: 07/22/2013] [Indexed: 11/29/2022]
Abstract
A number of beta-thalassemia (β-thal) patients in the course of the disease exhibit ectopic calcification affecting skin, eyes and the cardiovascular system. Clinical and histopathological features have been described similar to those in pseudoxanthoma elasticum (PXE), although different genes are affected in the two diseases. Cultured dermal fibroblasts from β-thal patients with and without PXE-like clinical manifestations have been compared for parameters of redox balance and for the expression of proteins, which have been already associated with the pathologic mineralisation of soft connective tissues. Even though oxidative stress is a well-known condition of β-thal patients, our results indicate that the occurrence of mineralized elastin is associated with a more pronounced redox disequilibrium, as demonstrated by the intracellular increase of anion superoxide and of oxidized proteins and lipids. Moreover, fibroblasts from β-thal PXE-like patients are characterized by decreased availability of carboxylated matrix Gla protein (MGP), as well as by altered expression of proteins involved in the vitamin K-dependent carboxylation process. Results demonstrate that elastic fibre calcification is promoted when redox balance threshold levels are exceeded and the vitamin K-dependent carboxylation process is affected decreasing the activity of MGP, a well-known inhibitor of ectopic calcification. Furthermore, independently from the primary gene defect, these pathways are similarly involved in fibroblasts from PXE and from β-thal PXE-like patients as well as in other diseases leading to ectopic calcification, thus suggesting that can be used as markers of pathologic mineralisation.
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Affiliation(s)
- Federica Boraldi
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy; PXELab, University of Modena and Reggio Emilia, Modena, Italy
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19
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Li Q, Uitto J. Mineralization/anti-mineralization networks in the skin and vascular connective tissues. Am J Pathol 2013; 183:10-8. [PMID: 23665350 PMCID: PMC3702739 DOI: 10.1016/j.ajpath.2013.03.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Accepted: 03/12/2013] [Indexed: 02/06/2023]
Abstract
Ectopic mineralization has been linked to several common clinical conditions with considerable morbidity and mortality. The mineralization processes, both metastatic and dystrophic, affect the skin and vascular connective tissues. There are several contributing metabolic and environmental factors that make uncovering of the precise pathomechanisms of these acquired disorders exceedingly difficult. Several relatively rare heritable disorders share phenotypic manifestations similar to those in common conditions, and, consequently, they serve as genetically controlled model systems to study the details of the mineralization process in peripheral tissues. This overview will highlight diseases with mineral deposition in the skin and vascular connective tissues, as exemplified by familial tumoral calcinosis, pseudoxanthoma elasticum, generalized arterial calcification of infancy, and arterial calcification due to CD73 deficiency. These diseases, and their corresponding mouse models, provide insight into the pathomechanisms of soft tissue mineralization and point to the existence of intricate mineralization/anti-mineralization networks in these tissues. This information is critical for understanding the pathomechanistic details of different mineralization disorders, and it has provided the perspective to develop pharmacological approaches to counteract the consequences of ectopic mineralization.
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Affiliation(s)
| | - Jouni Uitto
- Department of Dermatology and Cutaneous Biology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania
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20
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Boraldi F, Annovi G, Vermeer C, Schurgers LJ, Trenti T, Tiozzo R, Guerra D, Quaglino D. Matrix gla protein and alkaline phosphatase are differently modulated in human dermal fibroblasts from PXE patients and controls. J Invest Dermatol 2013; 133:946-54. [PMID: 23223140 DOI: 10.1038/jid.2012.460] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Mineralization of elastic fibers in pseudoxanthoma elasticum (PXE) has been associated with low levels of carboxylated matrix gla protein (MGP), most likely as a consequence of reduced vitamin K (vit K) availability. Unexpectedly, vit K supplementation does not exert beneficial effects on soft connective tissue mineralization in the PXE animal model. To understand the effects of vit K supplementation and in the attempt to interfere with pathways leading to the accumulation of calcium and phosphate within PXE-mineralized soft connective tissues, we have conducted in vitro studies on dermal fibroblasts isolated from control subjects and from PXE patients. Cells were cultured in standard conditions and in calcifying medium (CM) in the presence of vit K1 and K2, or levamisole, an alkaline phosphatase (ALP) inhibitor. Control and PXE fibroblasts were characterized by a similar dose-dependent uptake of both vit K1 and vit K2, thus promoting a significant increase of total protein carboxylation in all cell lines. Nevertheless, MGP carboxylation remained much less in PXE fibroblasts. Interestingly, PXE fibroblasts exhibited a significantly higher ALP activity. Consistently, the mineralization process induced in vitro by a long-term culture in CM appeared unaffected by vit K, whereas it was abolished by levamisole.
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Affiliation(s)
- Federica Boraldi
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
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21
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Kavukcuoglu NB, Li Q, Pleshko N, Uitto J. Connective tissue mineralization in Abcc6-/- mice, a model for pseudoxanthoma elasticum. Matrix Biol 2012; 31:246-52. [PMID: 22421595 DOI: 10.1016/j.matbio.2012.02.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Revised: 02/20/2012] [Accepted: 02/22/2012] [Indexed: 02/03/2023]
Abstract
Pseudoxanthoma elasticum (PXE) is a heritable multisystem disorder characterized by ectopic mineralization. However, the structure of the mineral deposits, their interactions with the connective tissue matrix, and the details of the progressive maturation of the mineral crystals are currently unknown. In this study, we examined the mineralization processes in Abcc6(-/-) mice, a model system for PXE, by energy dispersive X-ray and Fourier transform infrared imaging spectroscopy (FT-IRIS). The results indicated that the principal components of the mineral deposits were calcium and phosphate which co-localized within the histologically demonstrable lesions determined by topographic mapping. The Ca/P ratio increased in samples with progressive mineralization reaching the value comparable to that in endochondral bone. A progressive increase in mineralization was also reflected by increased mineral-to-matrix ratio determined by FT-IRIS. Determination of the mineral phases by FT-IRIS suggested progressive maturation of the mineral deposits from amorphous calcium phosphate to hydroxyapatite. These results provide critical information of the mechanisms of mineralization in PXE, with potential pharmacologic implications.
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Affiliation(s)
- N Beril Kavukcuoglu
- Department of Bioengineering, Temple University, Philadelphia, PA 19122, USA
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22
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Szabó Z, Váradi A, Li Q, Uitto J. ABCC6 does not transport adenosine - relevance to pathomechanism of pseudoxanthoma elasticum. Mol Genet Metab 2011; 104:421; author reply 422. [PMID: 21813308 DOI: 10.1016/j.ymgme.2011.07.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2011] [Accepted: 07/11/2011] [Indexed: 01/31/2023]
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Markello TC, Pak LK, St Hilaire C, Dorward H, Ziegler SG, Chen MY, Chaganti K, Nussbaum RL, Boehm M, Gahl WA. Vascular pathology of medial arterial calcifications in NT5E deficiency: implications for the role of adenosine in pseudoxanthoma elasticum. Mol Genet Metab 2011; 103:44-50. [PMID: 21371928 PMCID: PMC3081917 DOI: 10.1016/j.ymgme.2011.01.018] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2010] [Revised: 01/28/2011] [Accepted: 01/28/2011] [Indexed: 01/31/2023]
Abstract
Arterial Calcification due to Deficiency of CD73 (ACDC) results from mutations in the NT5E gene encoding the 5' exonucleotidase, CD73. We now describe the third familial case of ACDC, including radiological and histopathological details of the arterial calcifications. The medial lesions involve the entire circumference of the elastic lamina, in contrast to the intimal plaque-like disease of atherosclerosis. The demonstration of broken and fragmented elastic fibers leading to generalized vascular calcification suggests an analogy to pseudoxanthoma elasticum (PXE), which exhibits similar histopathology. Classical PXE is caused by deficiency of ABCC6, a C type ABC transporter whose ligand is unknown. Other C type ABC proteins transport nucleotides, so the newly described role of adenosine in inhibiting vascular calcification, along with the similarity of ACDC and PXE with respect to vascular pathology, suggests that adenosine may be the ligand for ABCC6.
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Affiliation(s)
- Thomas C Markello
- NIH Undiagnosed Diseases Program, Office of Rare Disease Research and National Human Genome Research Institute and NIH Clinical Center, National Institutes of Health, Bethesda, MD 20892, USA.
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24
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Abstract
The ABCC6 gene encodes an organic anion transporter protein, ABCC6/MRP6. Mutations in the gene cause a rare, recessive genetic disease, pseudoxanthoma elasticum, while the loss of one ABCC6 allele is a genetic risk factor in coronary artery disease. We review here the information available on gene structure, evolution as well as the present knowledge on its transcriptional regulation. We give a detailed description of the characteristics of the protein, and analyze the relationship between the distributions of missense disease-causing mutations in the predicted three-dimensional structure of the transporter, which suggests functional importance of the domain-domain interactions. Though neither the physiological function of the protein nor its role in the pathobiology of the diseases are known, a current hypothesis that ABCC6 may be involved in the efflux of one form of Vitamin K from the liver is discussed. Finally, we analyze potential strategies how the gene can be targeted on the transcriptional level to increase protein expression in order to compensate for reduced activity. In addition, pharmacologic correction of trafficking-defect mutants or suppression of stop codon mutations as potential future therapeutic interventions are also reviewed.
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Affiliation(s)
- András Váradi
- Institute of Enzymology, Hungarian Academy of Sciences, Budapest, Hungary.
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25
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Abstract
Pseudoxanthoma elasticum (PXE), a prototypic heritable disorder with ectopic mineralization, manifests with characteristic skin findings, ocular involvement and cardiovascular problems, with considerable morbidity and mortality. The classic forms of PXE are due to loss-of-function mutations in the ABCC6 gene, which encodes ABCC6, a transmembrane efflux transporter expressed primarily in the liver. Several lines of evidence suggest that PXE is a primary metabolic disorder, which in the absence of ABCC6 transporter activity, displays reduced plasma anti-mineralization capacity due to reduced fetuin-A and matrix gla-protein (MGP) levels. MGP requires to be activated by gamma-glutamyl carboxylation, a vitamin K-dependent reaction, to serve in an anti-mineralization role in the peripheral connective tissue cells. Although the molecules transported from the hepatocytes to circulation by ABCC6 in vivo remain unidentified, it has been hypothesized that a critical vitamin K derivative, such as reduced vitamin K conjugated with glutathione, is secreted to circulation physiologically, but not in the absence of ABCC6 transporter activity. As a result, activation of MGP by gamma-glutamyl carboxylase is diminished, allowing slow yet progressive mineralization of connective tissues characteristic of PXE. Understanding of the pathomechanistic details of PXE provides a basis for the development of targeted molecular therapies for this currently intractable disease.
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Affiliation(s)
- Jouni Uitto
- Department of Dermatology and Cutaneous Biology, Jefferson Medical College and Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, PA 19107, USA.
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26
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Fabbri E, Forni GL, Guerrini G, Borgna-Pignatti C. Pseudoxanthoma-elasticum-like syndrome and thalassemia: an update. Dermatol Online J 2009; 15:7. [PMID: 19903435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023] Open
Abstract
Pseudoxanthoma Elasticum (PXE) is an autosomal recessive, multisystem disorder affecting connective tissues. We describe three cases of the acquired PXE-like syndrome that often occurs in association with hemolytic anemias, in particular the hemoglobinopathies, and review the literature on the subject. The pathogenesis of the acquired PXE-like lesions is not yet completely understood. None of the mutations observed in the inherited form has been detected in the syndrome accompanying thalassemia. The cardiovascular complications could be life-threatening. Therefore, an close surveillance of these patients is mandatory.
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Hendig D, Zarbock R, Szliska C, Kleesiek K, Götting C. The local calcification inhibitor matrix Gla protein in pseudoxanthoma elasticum. Clin Biochem 2008; 41:407-12. [PMID: 18222176 DOI: 10.1016/j.clinbiochem.2007.12.023] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2007] [Revised: 12/22/2007] [Accepted: 12/27/2007] [Indexed: 01/22/2023]
Abstract
OBJECTIVES Recent studies have revealed the involvement of calcification inhibitory proteins in the pathogenesis of pseudoxanthoma elasticum (PXE). DESIGN AND METHODS We analyzed serum concentrations of the calcification inhibitor matrix Gla protein (MGP) in a large cohort of patients suffering from PXE (n=101), 34 first-degree relatives and 67 healthy controls. Moreover, we determined the distribution of the two MGP promoter polymorphisms c.-7G>A and c.-138T>C in the three cohorts. RESULTS We found significantly lower total MGP concentrations in the sera of PXE patients compared to healthy controls (p=0.0002). Furthermore, higher serum MGP concentrations could be correlated with a later PXE onset. Analysis of MGP promoter polymorphism frequencies revealed one MGP haplotype to be a potential protective co-factor in PXE. CONCLUSIONS Our findings point to a role of the local calcification inhibitor MGP in PXE manifestation.
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Affiliation(s)
- Doris Hendig
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany
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28
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Li Q, Jiang Q, Schurgers LJ, Uitto J. Pseudoxanthoma elasticum: reduced gamma-glutamyl carboxylation of matrix gla protein in a mouse model (Abcc6-/-). Biochem Biophys Res Commun 2007; 364:208-13. [PMID: 17942075 PMCID: PMC2700335 DOI: 10.1016/j.bbrc.2007.09.122] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2007] [Accepted: 09/24/2007] [Indexed: 01/03/2023]
Abstract
Pseudoxanthoma elasticum (PXE), a heritable multi-system disorder manifesting with ectopic mineralization of soft connective tissues, is caused by mutations in the ABCC6/MRP6 gene/protein system, but the mechanisms how the ABCC6 mutations lead to aberrant mineralization are currently unknown. In this study, we utilized a transgenic mouse model, Abcc6-/-, to examine the mineralization processes. We focused on matrix gla protein (MGP) which has been shown to be critical, when activated by gamma-carboxylation of glutamyl residues, for prevention of unwanted mineralization. The concentration of MGP in the serum of Abcc6-/- mice was significantly reduced when compared to wild-type controls (p<0.004). More importantly, MGP isolated from the liver of Abcc6-/- mice was largely under-carboxylated and therefore possesses no activity. Finally, examination of the Abcc6-/- mice revealed association of total and under-carboxylated forms of MGP with ectopic mineralization while the gamma-carboxylated form was essentially absent. These results suggest that MGP in Abcc6-/- mice is largely in inactive form and is unable to prevent the unwanted mineralization of connective tissues in PXE.
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Affiliation(s)
| | | | - Leon J. Schurgers
- Cardiovascular Research Institute and Vitak BV, University of Maastricht, Maastricht, The Netherlands
| | - Jouni Uitto
- Corresponding Author Jouni Uitto, M.D., Ph.D., Department of Dermatology and Cutaneous Biology, Jefferson Medical College, 233 S. 10th Street, Suite 450 BLSB, Philadelphia, PA 19107, USA, Tel: (215) 503-5785, Fax: (215) 503-5788, E-mail:
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29
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Gheduzzi D, Boraldi F, Annovi G, DeVincenzi CP, Schurgers LJ, Vermeer C, Quaglino D, Ronchetti IP. Matrix Gla protein is involved in elastic fiber calcification in the dermis of pseudoxanthoma elasticum patients. J Transl Med 2007; 87:998-1008. [PMID: 17724449 DOI: 10.1038/labinvest.3700667] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Mature MGP (Matrix gamma-carboxyglutamic acid protein) is known to inhibit soft connective tissues calcification. We investigated its possible involvement in pseudoxanthoma elasticum (PXE), a genetic disorder whose clinical manifestations are due to mineralization of elastic fibers. PXE patients have lower serum concentration of total MGP compared to controls (P<0.001). Antibodies specific for the noncarboxylated (Glu-MGP) and for the gamma-carboxylated (Gla-MGP) forms of MGP were assayed on ultrathin sections of dermis from controls and PXE patients. Normal elastic fibers in controls and patients were slightly positive for both forms of MGP, whereas Gla-MGP was more abundant within control's than within patient's elastic fibers (P<0.001). In patients' calcified elastic fibers, Glu-MGP intensively colocalized with mineral precipitates, whereas Gla-MGP precisely localized at the mineralization front. Data suggest that MGP is present within elastic fibers and is associated with calcification of dermal elastic fibers in PXE. To investigate whether local cells produce MGP, dermal fibroblasts were cultured in vitro and MGP was assayed at mRNA and protein levels. In spite of very similar MGP mRNA expression, cells from PXE patients produced 30% less of Gla-MGP compared to controls. Data were confirmed by immunocytochemistry on ultrathin sections. Normal fibroblasts in vitro were positive for both forms of MGP. PXE fibroblasts were positive for Glu-MGP and only barely positive for Gla-MGP (P<0.001). In conclusion, MGP is involved in elastic fiber calcification in PXE. The lower ratio of Gla-MGP over Glu-MGP in pathological fibroblasts compared to controls suggests these cells may play an important role in the ectopic calcification in PXE.
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Affiliation(s)
- Dealba Gheduzzi
- Department of Biomedical Sciences, University of Modena and Reggio Emilia, Modena, Italy
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30
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Jiang Q, Li Q, Uitto J. Aberrant mineralization of connective tissues in a mouse model of pseudoxanthoma elasticum: systemic and local regulatory factors. J Invest Dermatol 2007; 127:1392-402. [PMID: 17273159 DOI: 10.1038/sj.jid.5700729] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Pseudoxanthoma elasticum (PXE) is caused by mutations in the ABCC6 gene, but the cellular and molecular events leading to aberrant mineralization of soft tissues are unknown. To characterize the mineralization process, we examined a PXE animal model, the Abcc6-/- mouse, with respect to specific proteins serving as inhibitors of mineralization. The levels of calcium and phosphate in serum of these mice were normal, but the Abcc6-/- serum had less ability to prevent the mineral deposition induced by inorganic phosphate in a cell culture system. Addition of fetuin-A to the culture system prevented the mineralization. The calcium x phosphate product was markedly elevated in the mineralized vibrissae of Abcc6-/- mice, an early biomarker of the mineralization process, consistent with histopathologic findings. Levels of fetuin-A were slightly decreased in Abcc6-/- serum, and positive immunostaining for matrix-gla-protein (MGP), fetuin-A, and ankylosis protein (Ank) as well as alkaline phosphatase activity were strongly associated with the mineralization process. In situ hybridization demonstrated that the genes for MGP and Ank were expressed locally in vibrissae, whereas fetuin-A was expressed highly in the liver. These data suggest that the deposition of the bone-associated proteins spatially coincides with mineralization and actively regulates this process locally and systemically.
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Affiliation(s)
- Qiujie Jiang
- Department of Dermatology and Cutaneous Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
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31
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Munteanu M, Chercotä V. [Optic nerve drusen and angioid streaks in pseudoxanthoma elasticum]. Oftalmologia 2007; 51:99-102. [PMID: 17605281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The clinical study presents the association between optic disc drusen and angioid streaks in the context of pseudoxanthoma elasticum, in 8.5% (4 from 47) of the cases. The values are significantly higher compared to those from the normal population (0.34%). This result can be the consequence of pathogenic correlations between the two diseases, in which a role is attributed to the metabolic changes within the pseudoxanthoma elasticum. The starting point seems to be the accumulation of polyanions in the elastin of the cribriform plate, followed by disruption of axonal transport, mitochondrial extrusion and subsequent formation of optic disc drusen.
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32
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Le Saux O, Bunda S, VanWart CM, Douet V, Got L, Martin L, Hinek A. Serum factors from pseudoxanthoma elasticum patients alter elastic fiber formation in vitro. J Invest Dermatol 2006; 126:1497-505. [PMID: 16543900 PMCID: PMC5540375 DOI: 10.1038/sj.jid.5700201] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Pseudoxanthoma elasticum (PXE) is a heritable disorder mainly characterized by calcified elastic fibers in cutaneous, ocular, and vascular tissues. PXE is caused by mutations in ABCC6, a gene encoding an ABC transporter predominantly expressed in liver and kidneys. The functional relationship between ABCC6 and elastic fiber calcification is unknown. We speculated that ABCC6 deficiency in PXE patients induces a persistent imbalance in circulating metabolite(s), which may impair the synthetic abilities of normal elastoblasts or specifically alter elastic fiber assembly. Therefore, we compared the deposition of elastic fiber proteins in cultures of fibroblasts derived from PXE and unaffected individuals. PXE fibroblasts cultured with normal human serum expressed and deposited increased amounts of proteins, but structurally normal elastic fibers. Interestingly, normal and PXE fibroblasts as well as normal smooth muscle cells deposited abnormal aggregates of elastic fibers when maintained in the presence of serum from PXE patients. The expression of tropoelastin and other elastic fiber-associated genes was not significantly modulated by the presence of PXE serum. These results indicated that certain metabolites present in PXE sera interfered with the normal assembly of elastic fibers in vitro and suggested that PXE is a primary metabolic disorder with secondary connective tissue manifestations.
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Affiliation(s)
- Olivier Le Saux
- Department of Cell and Molecular Biology, John A Burns School of Medicine, University of Hawaii, Honolulu, Hawaii, USA.
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33
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Götting C, Hendig D, Adam A, Schön S, Schulz V, Szliska C, Kuhn J, Kleesiek K. Elevated xylosyltransferase I activities in pseudoxanthoma elasticum (PXE) patients as a marker of stimulated proteoglycan biosynthesis. J Mol Med (Berl) 2005; 83:984-92. [PMID: 16133423 DOI: 10.1007/s00109-005-0693-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2005] [Accepted: 06/06/2005] [Indexed: 10/25/2022]
Abstract
Pseudoxanthoma elasticum (PXE) is a hereditary disorder of the connective tissue characterized by extracellular matrix alterations with elastin fragmentation and excessive proteoglycan deposition. Xylosyltransferase I (XT-I, E.C. 2.4.2.26) is the initial enzyme in the biosynthesis of the glycosaminoglycan chains in proteoglycans and has been shown to be a marker of tissue remodeling processes. Here, we investigated for the first time serum XT-I activities in a large cohort of German PXE patients and their unaffected relatives. XT-I activities were measured in serum samples from 113 Caucasian patients with PXE and 103 unaffected first-degree family members. The occurrence of the frequent ABCC6 gene mutation c.3421C>T (R1141X) and the hypertension-associated genetic variants T174M and M235T in the angiotensinogen (AGT) gene were determined. Serum XT-I activities in male and female PXE patients were significantly increased compared to unaffected family members (male patients, mean value 0.96 mU/l, SD 0.37; male relatives, 0.78 mU/l, SD 0.29; female patients, 0.91 mU/l, SD 0.31; female relatives, 0.76 mU/l, SD 0.34; p<0.05). The mean XT-I activities in PXE patients with hypertension were 24% higher than in patients without increased blood pressure (p<0.05). The AGT T174M and M235T frequencies were not different in hypertensive PXE patients, normotensive PXE patients, family members or blood donors. Our data show that the altered proteoglycan biosynthesis in PXE patients is closely related to an increased XT-I activity in blood. Serum XT-I, the novel fibrosis marker, may be useful for the assessment of extracellular matrix alterations and disease activity in PXE.
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Affiliation(s)
- Christian Götting
- Institut für Laboratoriums-und Transfusionsmedizin, Herz-und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Georgstrasse 11, 32545 Bad Oeynhausen, Germany.
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34
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Arányi T, Ratajewski M, Bardóczy V, Pulaski L, Bors A, Tordai A, Váradi A. Identification of a DNA methylation-dependent activator sequence in the pseudoxanthoma elasticum gene, ABCC6. J Biol Chem 2005; 280:18643-50. [PMID: 15760889 DOI: 10.1074/jbc.m501139200] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
ABCC6 encodes MRP6, a member of the ABC protein family with an unknown physiological role. The human ABCC6 and its two pseudogenes share 99% identical DNA sequence. Loss-of-function mutations of ABCC6 are associated with the development of pseudoxanthoma elasticum (PXE), a recessive hereditary disorder affecting the elastic tissues. Various disease-causing mutations were found in the coding region; however, the mutation detection rate in the ABCC6 coding region of bona fide PXE patients is only approximately 80%. This suggests that polymorphisms or mutations in the regulatory regions may contribute to the development of the disease. Here, we report the first characterization of the ABCC6 gene promoter. Phylogenetic in silico analysis of the 5' regulatory regions revealed the presence of two evolutionarily conserved sequence elements embedded in CpG islands. The study of DNA methylation of ABCC6 and the pseudogenes identified a correlation between the methylation of the CpG island in the proximal promoter and the ABCC6 expression level in cell lines. Both activator and repressor sequences were uncovered in the proximal promoter by reporter gene assays. The most potent activator sequence was one of the conserved elements protected by DNA methylation on the endogenous gene in non-expressing cells. Finally, in vitro methylation of this sequence inhibits the transcriptional activity of the luciferase promoter constructs. Altogether these results identify a DNA methylation-dependent activator sequence in the ABCC6 promoter.
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MESH Headings
- Cell Line
- Cell Line, Tumor
- Cloning, Molecular
- CpG Islands
- DNA Methylation
- DNA, Complementary/metabolism
- Electrophoresis, Agar Gel
- Genes, Recessive
- Genes, Reporter
- Humans
- Introns
- Luciferases/metabolism
- Models, Genetic
- Multidrug Resistance-Associated Proteins/genetics
- Multidrug Resistance-Associated Proteins/metabolism
- Mutation
- Phylogeny
- Polymerase Chain Reaction
- Polymorphism, Genetic
- Promoter Regions, Genetic
- Pseudoxanthoma Elasticum/genetics
- Pseudoxanthoma Elasticum/metabolism
- RNA, Messenger/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Sulfites/chemistry
- Transcription, Genetic
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Affiliation(s)
- Tamás Arányi
- Institute of Enzymology, Hungarian Academy of Sciences, H-1113 Budapest, Hungary.
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35
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Gheduzzi D, Guerra D, Bochicchio B, Pepe A, Tamburro AM, Quaglino D, Mithieux S, Weiss AS, Pasquali Ronchetti I. Heparan sulphate interacts with tropoelastin, with some tropoelastin peptides and is present in human dermis elastic fibers. Matrix Biol 2005; 24:15-25. [PMID: 15748998 DOI: 10.1016/j.matbio.2004.12.001] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2004] [Revised: 10/14/2004] [Accepted: 12/10/2004] [Indexed: 11/19/2022]
Abstract
A number of reports point to the presence of proteoglycans and/or glycosaminoglycans within elastic fibers in normal and in pathological conditions. We present data that heparan sulphate (HS)-containing proteoglycans are associated with normal elastic fibers in human dermis and that isolated HS chains interact in vitro with recombinant tropoelastin and with peptides encoded by distinct exons of the human tropoelastin gene (EDPs). By immunocytochemistry, HS chains were identified as associated with the amorphous elastin component in the human dermis and remained associated with the residual elastin in the partially degenerated fibers of old subjects. HS appeared particularly concentrated in the mineralization front of elastic fibers in the dermis of patients affected by pseudoxanthoma elasticum (PXE). In in vitro experiments, HS induced substantial changes in the coacervation temperature and in the aggregation properties of recombinant tropoelastin and of synthetic peptides (EDPs) corresponding to sequences encoded by exons 18, 20, 24 and 30 of the human tropoelastin gene. In particular, HS modified the coacervation temperature and favoured the aggregation into ordered structures of tropoelastin molecules and of EDPs 18, 20 and 24, but not of EDP30. These data strongly indicate that HS-elastin interactions may play a role in tissue elastin fibrogenesis as well as modulating elastin stability with time and in diseases.
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Affiliation(s)
- Dealba Gheduzzi
- Department of Biomedical Sciences, University of Modena and Reggio Emilia, Via Campi 287, 41100-Modena, Italy
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36
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Quaglino D, Sartor L, Garbisa S, Boraldi F, Croce A, Passi A, De Luca G, Tiozzo R, Pasquali-Ronchetti I. Dermal fibroblasts from pseudoxanthoma elasticum patients have raised MMP-2 degradative potential. Biochim Biophys Acta Mol Basis Dis 2004; 1741:42-7. [PMID: 15955448 DOI: 10.1016/j.bbadis.2004.09.012] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2004] [Revised: 09/18/2004] [Accepted: 09/27/2004] [Indexed: 11/24/2022]
Abstract
Cultured fibroblasts from the dermis of normal subjects and of Pseudoxanthoma elasticum (PXE) patients were analysed for enzyme activity, protein and mRNA expression of metalloproteases (MMP-2, MMP-3, MMP-9, MT1-MMP) and of their specific inhibitors (TIMP-1, TIMP-2 and TIMP-3). MMP-3, MMP-9 and TIMP-3 mRNAs and proteins failed to be detected in both the medium and the cell layer of both controls and PXE patients. MMP-2 mRNA was significantly more expressed in PXE than in control cell lines, whereas MT1-MMP, TIMP-1 and TIMP-2 mRNAs appeared unchanged. MMP-2 was significantly higher in the cell extracts from PXE fibroblasts than in control cells, whereas differences were negligible in the cell medium. Data suggest that PXE fibroblasts have an increased proteolytic potential, and that MMP-2 may actively contribute to connective tissue alterations in this genetic disorder.
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Affiliation(s)
- Daniela Quaglino
- Department of Biomedical Sciences, University of Modena and Reggio Emilia, Via Campi 287, 41100 Modena, Italy.
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37
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Kornet L, Bergen AAB, Hoeks APG, Cleutjens JP, Oostra RJ, Daemen MJ, van Soest S, Reneman RS. In patients with pseudoxanthoma elasticum a thicker and more elastic carotid artery is associated with elastin fragmentation and proteoglycans accumulation. Ultrasound Med Biol 2004; 30:1041-1048. [PMID: 15474747 DOI: 10.1016/j.ultrasmedbio.2004.06.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2003] [Revised: 06/01/2004] [Accepted: 06/10/2004] [Indexed: 05/24/2023]
Abstract
Skin biopsies in patients with pseudoxanthoma elasticum (PXE) show elastic fiber fragmentation and calcium and proteoglycans accumulation. Assuming such changes to be present in the artery wall as well, we studied the influence of such alterations on function and structure of the human common carotid artery (CCA). Indeed, elastin fragmentation and increased calcium and proteoglycans content were present in the arteries of the two PXE patients examined. Internal diameter, distension and intima-media thickness (IMT) in the CCA of PXE patients (n = 19) and controls (n = 39) were determined by ultrasound (US). Pulse pressure was assessed in the brachial artery. The distensibility and compliance coefficients as well as the Young's modulus were calculated. Diameter and pulse pressure were not significantly different in PXE patients and controls. The distensibility and compliance coefficients were significantly greater in older PXE patients than in older controls. The distensibility coefficient decreased with age in both PXE patients and in controls. Unlike in controls, the compliance coefficient did not decrease and the Young's modulus barely increased with age in PXE patients. IMT was significantly greater at both younger and older ages and the Young's modulus was significantly smaller at older ages in PXE patients than in controls. The carotid artery is thicker and more elastic in PXE patients than in control subjects; differences are most pronounced at older ages. These alterations might be explained by the elastin fragmentation and proteoglycans accumulation as observed in these patients.
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Affiliation(s)
- Lilian Kornet
- Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
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38
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Götting C, Schulz V, Hendig D, Grundt A, Dreier J, Szliska C, Brinkmann T, Kleesiek K. Assessment of a rapid-cycle PCR assay for the identification of the recurrent c.3421C>T mutation in the ABCC6 gene in pseudoxanthoma elasticum patients. Lab Invest 2004; 84:122-30. [PMID: 14631379 DOI: 10.1038/sj.labinvest.3700004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Pseudoxanthoma elasticum (PXE) is a heritable disorder of the connective tissue. Mutations in the ABCC6 gene could be linked to this disease and, just recently, the c.3421C>T mutation was also associated with a high risk of coronary artery disease. We have now developed new real-time PCR assays for the accurate and rapid determination of the c.3421C>T genotype. Using our new assay, we analyzed the presence of the c.3421C>T mutation in the largest collection of DNA samples from unrelated German PXE patients (n=64) and in a control cohort (n=910). For assay setup, two sets of samples with known genotype for the c.3421C>T mutation were analyzed over a period of 14 days. Results were confirmed by restriction endonuclease mapping, sequence-specific PCR and DNA sequencing. In order to ensure that no further mutations or deletions interfered with the c.3421C>T genotyping, we scanned the exon 24 of the ABCC6 gene by DHPLC and investigated the presence of the ABCC6del23-29 deletion in all patients. The assay has been set up on a group of patients with known genotype and validated on 64 PXE patients. In this group four PXE patients (6.3%) were found to be homozygous and 25 (39.0%) to be heterozygous carriers of the c.3421C>T mutation. The common ABCC6del23-29 deletion, possibly interfering with genotype determination, was searched and excluded. Furthermore, two novel mutations in the ABCC6 gene could be identified in two patients. The novel mutations c.3389C>T and c.3341G>A did not interfere with our new assay. Our new c.3421C>T genotyping assays can be used for the rapid identification of this frequent mutation in PXE patients and of the recently newly proposed cardiac risk factor in young patients with myocardial infarcts of unknown origin.
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Affiliation(s)
- Christian Götting
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany.
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Annovazzi L, Viglio S, Gheduzzi D, Pasquali-Ronchetti I, Zanone C, Cetta G, Iadarola P. High levels of desmosines in urine and plasma of patients with pseudoxanthoma elasticum. Eur J Clin Invest 2004; 34:156-64. [PMID: 14764080 DOI: 10.1111/j.1365-2362.2004.01306.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Pseudoxanthoma elasticum (PXE), a rare heritable disorder caused by mutations of the ABCC6 gene, is characterized by fragmentation and mineralization of elastic fibres. We determined the extent of degradation of elastin by measuring and comparing the amount of desmosines in plasma and urine of PXE patients, healthy carriers and normal subjects. METHODS Using capillary electrophoresis with laser-induced fluorescence detection (CE-LIF) we measured the amount of desmosines in the urine of 46 individuals (14 PXE patients, 17 healthy carriers and 15 controls) and in the plasma of 56 subjects (18 PXE patients, 23 healthy carriers and 15 controls). Pseudoxanthoma elasticum patients and carriers were identified by clinical, structural and molecular biology analyses. RESULTS The urinary excretion of desmosines was two-fold higher in PXE patients than in controls (P < 0.01); the values for healthy carriers were intermediate between those of PXE patients and controls. A very similar trend between patients and their relatives was observed for plasma desmosines. There was a significant correlation between the amount of the desmosines in plasma and urine. Moreover, a positive correlation was observed between urinary desmosine content and age of the patients as well as between urinary desmosine content and severity of clinical manifestations. CONCLUSIONS Both the urinary and plasma desmosine concentrations indicate that elastin degradation is higher in PXE patients and, to a lesser extent, in healthy carriers than in normal subjects. Data seem to indicate that the amount of elastin breakdown products correlates with the age of patients as well as with the severity of the disease.
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Affiliation(s)
- L Annovazzi
- Università di Pavia, Pavia, and Università di Modena e Reggio Emilia, Modena, Italy
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Boraldi F, Quaglino D, Croce MA, Garcia Fernandez MI, Tiozzo R, Gheduzzi D, Bacchelli B, Pasquali Ronchetti I. Multidrug resistance protein-6 (MRP6) in human dermal fibroblasts. Comparison between cells from normal subjects and from Pseudoxanthoma elasticum patients. Matrix Biol 2003; 22:491-500. [PMID: 14667841 DOI: 10.1016/j.matbio.2003.09.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Multidrug resistance protein-6 (MRP6) is a membrane transporter whose deficiency leads to the connective tissue disorder Pseudoxanthoma elasticum (PXE). In vitro dermal fibroblasts from normal and PXE subjects, homozygous for the R1141X mutation, were compared for their ability to accumulate and to release fluorescent calcein, in the absence and in the presence of inhibitors and competitors of the MDR-multidrug resistance protein (MRP) systems, such as 3-(3-(2-(7-choro-2 quinolinyl) ethenyl)phenyl ((3-dimethyl amino-3-oxo-propyl)thio) methyl) propanoic acid (MK571), verapamil (VPL), vinblastine (VBL), chlorambucil (CHB), benzbromarone (BNZ) and indomethacin (IDM). In the absence of chemicals, calcein accumulation was significantly higher and the release significantly slower in PXE cells compared to controls. VBL and CHB reduced calcein release in both cell strains, without affecting the differences between PXE and control fibroblasts. VPL, BNZ and IDM consistently delayed calcein release from both control and PXE cells; moreover, they abolished the differences between normal and MRP6-deficient fibroblasts observed in the absence of chemicals. These findings suggest that VPL, BNZ and IDM interfere with MRP6-dependent calcein extrusion in in vitro human normal fibroblasts. Interestingly, MK571 almost completely abolished calcein release from PXE cells, whereas it induced a strong but less complete inhibition in control fibroblasts, suggesting that MRP6 is not inhibited by MK571. Data show that MRP6 is active in human fibroblasts, and that its sensitivity to inhibitors and competitors of MDR-MRPs' membrane transporters is different from that of other translocators, namely, MRP1. It could be suggested that MRP1 and MRP6 transport different physiological substances and that MRP6 deficiency cannot be overcome by other membrane transporters, at least in fibroblasts. These data further support the hypothesis that MRP6 deficiency may be relevant for fibroblast metabolism and responsible for the metabolic alterations of these cells at the basis of connective tissue clinical manifestations of PXE.
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Affiliation(s)
- F Boraldi
- Department of Biomedical Sciences, University of Modena and Reggio Emilia, via Campi 287, 41100 Modena, Italy
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Akagi A, Tajima S, Kawada A, Ishibashi A. Coexistence of pseudoxanthoma elasticum-like papillary dermal elastolysis and linear focal dermal elastosis. J Am Acad Dermatol 2002; 47:S189-92. [PMID: 12140459 DOI: 10.1067/mjd.2002.108495] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
An 89-year-old Japanese woman had pseudoxanthoma elasticum-like papillary dermal elastolysis on the neck and linear focal elastosis on the flexor aspects of the legs and thighs. The lesions of both diseases had similar histologic patterns-loss of elastic fibers in the papillary dermis and accumulation of normal-appearing elastic fibers in the subpapillary or mid dermis. Immunohistochemical analysis showed elastin, and microfibril-associated proteins (fibrillin 1 and 2 and microfibril associated glycoprotein 1 and 4) were absent or decreased in the papillary dermis and present in the accumulated elastic fibers in both lesions. The association of 2 diseases on different areas of the same patient and histologic and immunohistologic similarities between the diseases suggest that, despite the clinical differences, both diseases are closely related.
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Affiliation(s)
- Atsushi Akagi
- Department of Dermatology, National Defense Medical College, Saitama, Japan
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42
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Iliás A, Urbán Z, Seidl TL, Le Saux O, Sinkó E, Boyd CD, Sarkadi B, Váradi A. Loss of ATP-dependent transport activity in pseudoxanthoma elasticum-associated mutants of human ABCC6 (MRP6). J Biol Chem 2002; 277:16860-7. [PMID: 11880368 DOI: 10.1074/jbc.m110918200] [Citation(s) in RCA: 195] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mutations in the ABCC6 (MRP6) gene cause pseudoxanthoma elasticum (PXE), a rare heritable disorder resulting in the calcification of elastic fibers. In the present study a cDNA encoding a full-length normal variant of ABCC6 was amplified from a human kidney cDNA library, and the protein was expressed in Sf9 insect cells. In isolated membranes ATP binding as well as ATP-dependent active transport by ABCC6 was demonstrated. We found that glutathione conjugates, including leukotriene C(4) and N-ethylmaleimide S-glutathione (NEM-GS), were actively transported by human ABCC6. Organic anions (probenecid, benzbromarone, indomethacin), known to interfere with glutathione conjugate transport of human ABCC1 and ABCC2, inhibited the ABCC6-mediated NEM-GS transport in a specific manner, indicating that ABCC6 has a unique substrate specificity. We have also expressed three missense mutant forms of ABCC6, which have recently been shown to cause PXE. MgATP binding was normal in these proteins; ATP-dependent NEM-GS or leukotriene C(4) transport, however, was abolished. Our data indicate that human ABCC6 is a primary active transporter for organic anions. In the three ABCC6 mutant forms examined, the loss of transport activity suggests that these mutations result in a PXE phenotype through a direct influence on the transport activity of this ABC transporter.
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Affiliation(s)
- Attila Iliás
- Institute of Enzymology, Hungarian Academy of Sciences, 1113 Budapest, Hungary
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43
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Hirano E, Fujimoto N, Tajima S, Akiyama M, Ishibashi A, Kobayashi R, Okamoto K. Expression of 36-kDa microfibril-associated glycoprotein (MAGP-36) in human keratinocytes and its localization in skin. J Dermatol Sci 2002; 28:60-7. [PMID: 11916131 DOI: 10.1016/s0923-1811(01)00148-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Microfibril-associated glycoprotein-36 (MAGP-36) is a recently isolated elastin-binding protein and considered to be a member of microfibril-associated glycoproteins (MAGPs). We studied the expression of MAGP-36 in cultured normal human keratinocytes and its localization in the skin. MAGP-36 was found to be expressed in cultured human keratinocytes by Western blot and RT-PCR assays. The levels of MAGP-36 (polypeptide and mRNA) and the number of MAGP-36-producing keratinocytes were greatly increased during Ca(2+)-induced differentiation of keratinocytes. Immunohistochemical studies demonstrated that MAGP-36 colocalized with elastic fibers and formed candelabra like-fibers in the superficial dermis of normal skin. In the elderly skin of sun-exposed region, immunoreactivity of MAGP-36 in the superficial dermis disappeared. In the lesional skin of pseudoxanthoma elasticum which is an elastin-related disorder, immunoreactivity of MAGP-36 was found in the accumulation of disintegrated elastic fibers. The results show that MAGP-36 is a component of elastic fibers in the dermis and co-operates with elastin in normal and diseased conditions.
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Affiliation(s)
- Eiichi Hirano
- Department of Biochemical Engineering and Science, Kyusyu Institute of Technology, Iizuka, Fukuoka, Japan
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44
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Affiliation(s)
- F C Luft
- Franz-Volhard-Klinik, Humboldt University of Berlin, Berlin-Buch, Germany.
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45
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Baccarani-Contri M, Bacchelli B, Boraldi F, Quaglino D, Taparelli F, Carnevali E, Francomano MA, Seidenari S, Bettoli V, De Sanctis V, Pasquali-Ronchetti I. Characterization of pseudoxanthoma elasticum-like lesions in the skin of patients with beta-thalassemia. J Am Acad Dermatol 2001; 44:33-9. [PMID: 11148474 DOI: 10.1067/mjd.2001.110045] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND Pseudoxanthoma elasticum (PXE), an inherited disorder of unknown pathogenesis, is characterized by elastic fiber mineralization, collagen fibril alterations, and accumulation of thread material in the extracellular space. PXE-like clinical lesions have been described in patients with beta-thalassemia. OBJECTIVE AND METHODS Dermal lesions in these two genetic disorders were compared by light and electron microscopy and by immunocytochemistry. RESULTS In both disorders, elastic fiber polymorphism, fragmentation, and mineralization were structurally identical. Elastic fiber mineralization in beta-thalassemia was associated with vitronectin, bone sialoprotein, and alkaline phosphatase, similar to what was observed in inherited PXE. Furthermore, abnormalities of collagen fibrils and filament aggregates were identical in both disorders. In both inherited and beta-thalassemia-associated PXE, unrelated gene defects seem to induce cell metabolic abnormalities that lead to identical clinical and structural phenotypes. CONCLUSION Data indicate that patients with beta-thalassemia may undergo important alterations of connective tissues, a better understanding of which may help in preventing clinical complications.
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Affiliation(s)
- M Baccarani-Contri
- Department of Biomedical Sciences, General Pathology Unit, University of Modena and Reggio Emilia, Italy
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Quaglino D, Boraldi F, Barbieri D, Croce A, Tiozzo R, Pasquali Ronchetti I. Abnormal phenotype of in vitro dermal fibroblasts from patients with Pseudoxanthoma elasticum (PXE). Biochim Biophys Acta 2000; 1501:51-62. [PMID: 10727849 DOI: 10.1016/s0925-4439(00)00007-7] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Pseudoxanthoma elasticum (PXE) is a genetic connective tissue disease, whose gene and pathogenesis are still unknown. Dermal fibroblasts from patients affected by PXE have been compared in vitro with fibroblasts taken from sex and age-matched normal individuals. Cells were grown and investigated in monolayer, into three-dimensional collagen gels and in suspension. Compared with normal cells, PXE fibroblasts cultured in monolayer entered more rapidly within the S phase and exhibited an increased proliferation index; on the contrary, similarly to normal fibroblasts, PXE cells did not grow in suspension. Furthermore, compared with normal fibroblasts, PXE cells exhibited lower efficiency in retracting collagen type I lattices and lower adhesion properties to collagen type I and to plasma fibronectin. This behavior was associated with higher expression of integrin subunits alpha2, alpha5, alphav, whereas beta1 subunit as well as alpha2beta1 and alpha5beta1 integrin expression was lower than in controls. Compared to controls, PXE fibroblasts had higher CAM protein expression in accordance with their high tendency to form cellular aggregates, when kept in suspension. The demonstration that PXE fibroblasts have altered cell-cell and cell-matrix interactions, associated with modified proliferation capabilities, is consistent with the hypothesis that the gene responsible for PXE might have a broad regulatory role on the cellular machinery.
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Affiliation(s)
- D Quaglino
- Department of Biomedical Sciences- General Pathology, University of Modena and Reggio Emilia, Via Campi 287, 41100, Modena, Italy.
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Tajima S, Tanaka N, Ohnishi Y, Ishibashi A, Kajiya H, Osakabe T, Seyama Y, Sakamoto H. Analysis of elastin metabolism in patients with late-onset focal dermal elastosis. Acta Derm Venereol 1999; 79:285-7. [PMID: 10429985 DOI: 10.1080/000155599750010670] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022] Open
Abstract
Late-onset focal dermal elastosis has recently been described as new clinical entity characterized by pseudoxanthoma elasticum-like eruptions and an accumulation of normal-appearing elastic fibres in the dermis. Elastin and collagen contents of the skin of 2 patients were 2- and 1.4-fold higher than in the skin of controls, respectively. A focal accumulation of elastin but not of fibrillin-1 was observed by immunohistochemical staining. The levels of type I and III collagen and elastin mRNAs isolated from cultured patient fibroblasts were elevated 2-3-fold compared with control fibroblasts. There was no significant change in the excretion of elastin peptides in the urine of patients and controls. These results suggest that the focal accumulation of elastic fibres in the patient skin may be related to overexpression of elastin rather than to altered degradation of elastin.
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Affiliation(s)
- S Tajima
- Department of Dermatology, National Defense Medical College, Saitama, Japan
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48
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Ohnishi Y, Tajima S, Ishibashi A, Inazumi T, Sasaki T, Sakamoto H. Pseudoxanthoma elasticum-like papillary dermal elastolysis: report of four Japanese cases and an immunohistochemical study of elastin and fibrillin-1. Br J Dermatol 1998; 139:141-4. [PMID: 9764167 DOI: 10.1046/j.1365-2133.1998.02332.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We report four patients with pseudoxanthoma elasticum-like papillary dermal elastolysis (PDE). Multiple small papules on the neck, clinically resembling pseudoxanthoma elasticum, and loss of the elastic fibre network in the papillary dermis were found in each case. Immunohistochemical staining for elastin and fibrillin-1 in one patient demonstrated the disappearance of elastin and fibrillin-1 in the papillary dermis. Site-matched normal skins of the elderly showed intact elastin but a lack of fibrillin-1 in the papillary dermis. The younger normal skins revealed intact elastin and fibrillin-1. The results suggest that fibrillin-1 is absent from the papillary dermis of the normal-appearing neck skin of the elderly and that the primary defect in PDE may be in elastin rather than in fibrillin-1.
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Affiliation(s)
- Y Ohnishi
- Department of Dermatology, National Defense Medical College, Saitama, Japan
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Karonen T, Jeskanen L, Keski-Oja J. Transforming growth factor beta 1 and its latent form binding protein-1 associate with elastic fibres in human dermis: accumulation in actinic damage and absence in anetoderma. Br J Dermatol 1997; 137:51-8. [PMID: 9274625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Latent transforming growth factor-beta 1 (TGF-beta 1) and its binding protein-1 (LTBP-1) are components of the extracellular matrix microfibrils of cultured human fibroblasts. Using immunohistochemistry we have studied the localization of TGF-beta 1 and LTBP-1 and compared their distribution with that of elastic fibres in the interstitial connective tissue matrix of the human dermis. Prominent LTBP-1 specific fibrillar staining co-localized with the elastic fibres in normal human skin. Co-distribution was also observed in a number of pathological states of the elastic fibres such as solar elastosis, solar keratosis and pseudoxanthoma elasticum. TGF-beta 1 had a staining pattern similar to that of LTBP-1 in solar elastosis and solar keratosis. No staining for LTBP-1 or TGF-beta 1 was found in dermis devoid of elastic fibres, as in anetoderma. LTBP-1 is released from the extracellular matrix of cultured human fibroblasts, epithelial and endothelial cells by proteases. Analogously, the immunoreactivity for LTBP-1 and TGF-beta 1 were also lost from the skin sections by elastase, and by trypsin, a protease pretreatment commonly used in immunohistochemistry. These results indicate that LTBP-1 is a component of the elastin-associated microfibrils of the interstitial connective tissue matrix of human skin. Furthermore, the small latent form of TGF-beta 1 is likely to associate with the extracellular matrix of human dermis via LTBP-1. The release of latent TGF-beta 1 from the matrix, as a consequence of proteolytic cleavage of LTBP-1, is a plausible extracellular mechanism for the regulation of TGF-beta 1 activation.
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Affiliation(s)
- T Karonen
- Department of Dermatology, University of Helsinki, Finland
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50
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Piccoli A, Ricciardi D, Santucci A, Barnaba V, Ferri C. Elevated levels of plasma endothelin-1, von Willebrand factor, and urinary albumin excretion in three relatives with pseudoxanthoma elasticum. Thromb Haemost 1996; 76:278-9. [PMID: 8865548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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