1
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Hausman-Kedem M, Krishnan P, Dlamini N. Cerebral arteriopathies of childhood and stroke - A focus on systemic arteriopathies and pediatric fibromuscular dysplasia (FMD). Vasc Med 2024; 29:328-341. [PMID: 38898630 PMCID: PMC11188572 DOI: 10.1177/1358863x241254796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Systemic vascular involvement in children with cerebral arteriopathies is increasingly recognized and often highly morbid. Fibromuscular dysplasia (FMD) represents a cerebral arteriopathy with systemic involvement, commonly affecting the renal and carotid arteries. In adults, FMD diagnosis and classification typically relies on angiographic features, like the 'string-of-beads' appearance, following exclusion of other diseases. Pediatric FMD (pFMD) is considered equivalent to adult FMD although robust evidence for similarities is lacking. We conducted a comprehensive literature review on pFMD and revealed inherent differences between pediatric and adult-onset FMD across various domains including epidemiology, natural history, histopathophysiology, clinical, and radiological features. Although focal arterial lesions are often described in children with FMD, the radiological appearance of 'string-of-beads' is highly nonspecific in children. Furthermore, children predominantly exhibit intimal-type fibroplasia, common in other childhood monogenic arteriopathies. Our findings lend support to the notion that pFMD broadly reflects an undefined heterogenous group of monogenic systemic medium-or-large vessel steno-occlusive arteriopathies rather than a single entity. Recognizing the challenges in categorizing complex morphologies of cerebral arteriopathy using current classifications, we propose a novel term for describing children with cerebral and systemic vascular involvement: 'cerebral and systemic arteriopathy of childhood' (CSA-c). This term aims to streamline patient categorization and, when coupled with advanced vascular imaging and high-throughput genomics, will enhance our comprehension of etiology, and accelerate mechanism-targeted therapeutic developments. Lastly, in light of the high morbidity in children with cerebral and systemic arteriopathies, we suggest that investigating for systemic vascular involvement is important in children with cerebral arteriopathies.
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Affiliation(s)
- Moran Hausman-Kedem
- Pediatric Neurology Institute, Tel Aviv Medical Center, Tel Aviv, affiliated to the Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Pradeep Krishnan
- Department of Pediatric Neuroradiology, The Hospital for Sick Children, Toronto, ON, Canada
| | - Nomazulu Dlamini
- Division of Neurology, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
- Neurosciences and Mental Health Program, The Hospital for Sick Children, Toronto, ON, Canada
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2
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Brunet-Garcia L, Prada Martínez FH, Sanchez-de-Toledo J, Carretero Bellón JM. Massive Dilatation of the Ascending Aorta in a Patient With Generalized Arterial Calcification of Infancy. World J Pediatr Congenit Heart Surg 2023; 14:93-95. [PMID: 36226411 DOI: 10.1177/21501351221129188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We report a case of massive ascending aortic dilatation in a patient with generalized arterial calcification of infancy (GACI). He was found to carry compound heterozygous mutations in ABCC6 gene, previously associated with pseudoxanthoma elasticum, although recently linked to GACI. Our case confirms previous reports of a genotypic overlap between both entities.
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Affiliation(s)
- Laia Brunet-Garcia
- Department of Pediatric Cardiology, 16380Hospital de Mataró, Consorci Sanitari del Maresme, Barcelona, Spain
| | | | | | - Juan Manuel Carretero Bellón
- Department of Pediatric Cardiology, 16512Hospital Sant Joan de Déu, Barcelona, Spain.,Department of Pediatric Cardiology, Hospital Universitari Joan XXIII, Universitat Rovira i Virgili, Tarragona, Spain
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3
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Fãgãrãşan A, Gozar L, Ghiragosian SER, Murariu M, Pop M, Crauciuc A, Miclea D, Şuteu CC. Severe early-onset manifestations of generalized arterial calcification of infancy (mimicking severe coarctation of the aorta) with ABCC6 gene variant - Case report and literature review. Front Cardiovasc Med 2022; 9:1032519. [PMID: 36606277 PMCID: PMC9807665 DOI: 10.3389/fcvm.2022.1032519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 10/24/2022] [Indexed: 12/24/2022] Open
Abstract
Introduction Generalized arterial calcification of infancy (GACI) is a rare cause of infantile heart failure and systemic hypertension with a poor prognosis, characterized by extensive calcification and proliferation of the intimal layer of large and medium sized arteries. Case report We present the first case report of successful surgical treatment of severe aortic arch obstruction by calcified plaques mimicking severe coarctation of the aorta and the outcome (of bisphosphonate therapy) in a newborn with GACI. Furthermore, we report the identification of a variant in ATP Binding Cassette Subfamily C, Member 6 (ABCC6) gene, possibly associated with severe early-onset manifestations of GACI. Conclusion This case report highlights the importance of considering GACI in an infant with heart failure, systemic hypertension, and evidence of increased echogenicity of the arterial vessels. We noted the favorable outcome in improving the aortic calcification in our patient after surgical treatment and bisphosphonates therapy. Early diagnosis and treatment improve the long-term prognosis. A better understanding of this rare genetic disease could lead to new therapeutic strategies.
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Affiliation(s)
- Amalia Fãgãrãşan
- Clinic of Pediatric Cardiology, Emergency Institute of Cardiovascular Diseases and Transplantation, Târgu Mureş, Romania,Department of Pediatrics III, George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Târgu Mureş, Târgu Mureş, Romania
| | - Liliana Gozar
- Clinic of Pediatric Cardiology, Emergency Institute of Cardiovascular Diseases and Transplantation, Târgu Mureş, Romania,Department of Pediatrics III, George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Târgu Mureş, Târgu Mureş, Romania,*Correspondence: Liliana Gozar,
| | - Simina-Elena Rusu Ghiragosian
- Department of Pediatrics III, George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Târgu Mureş, Târgu Mureş, Romania,Simina-Elena Rusu Ghiragosian,
| | - Mircea Murariu
- Clinic of Pediatric Cardiology, Emergency Institute of Cardiovascular Diseases and Transplantation, Târgu Mureş, Romania
| | - Marian Pop
- ME1 Department, George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Târgu Mureş, Târgu Mureş, Romania,Department of Radiology, Emergency Institute for Cardiovascular Diseases and Heart Transplant, Târgu Mureş, Romania
| | - Andrei Crauciuc
- Clinic of Pediatric Cardiology, Emergency Institute of Cardiovascular Diseases and Transplantation, Târgu Mureş, Romania
| | - Diana Miclea
- Department of Medical Genetics, “Iuliu Hatieganu” University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | - Carmen Corina Şuteu
- Clinic of Pediatric Cardiology, Emergency Institute of Cardiovascular Diseases and Transplantation, Târgu Mureş, Romania
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4
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Hausman-Kedem M, Herring R, Torres MD, Santoro JD, Kaseka ML, Vargas C, Amico G, Bertamino M, Nagesh D, Tilley J, Schenk A, Ben-Shachar S, Musolino PL. The Genetic Landscape of Ischemic Stroke in Children - Current Knowledge and Future Perspectives. Semin Pediatr Neurol 2022; 44:100999. [PMID: 36456039 DOI: 10.1016/j.spen.2022.100999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Revised: 09/12/2022] [Accepted: 09/12/2022] [Indexed: 11/18/2022]
Abstract
Stroke in childhood has multiple etiologies, which are mostly distinct from those in adults. Genetic discoveries over the last decade pointed to monogenic disorders as a rare but significant cause of ischemic stroke in children and young adults, including small vessel and arterial ischemic stroke. These discoveries contributed to the understanding that stroke in children may be a sign of an underlying genetic disease. The identification of these diseases requires a detailed medical and family history collection, a careful clinical evaluation for the detection of systemic symptoms and signs, and neuroimaging assessment. Establishing an accurate etiological diagnosis and understanding the genetic risk factors for stroke are essential steps to decipher the underlying mechanisms, optimize the design of tailored prevention strategies, and facilitate the identification of novel therapeutic targets in some cases. Despite the increasing recognition of monogenic causes of stroke, genetic disorders remain understudied and therefore under-recognized in children with stroke. Increased awareness among healthcare providers is essential to facilitate accurate diagnosis in a timely manner. In this review, we provide a summary of the main single-gene disorders which may present as ischemic stroke in childhood and describe their clinical manifestations. We provide a set of practical suggestions for the diagnostic work up of these uncommon causes of stroke, based upon the stroke subtype and imaging characteristics that may suggest a monogenic diagnosis of ischemic stroke in children. Current hurdles in the genetic analyses of children with ischemic stroke as well as future prospectives are discussed.
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Affiliation(s)
- Moran Hausman-Kedem
- Pediatric Neurology Institute, Dana Children's Hospital, Tel Aviv Sourasky Medical Center, Israel; The Sacker Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
| | - Rachelle Herring
- Neurology Department, Cook Children's Medical Center, Fort Worth, TX, USA
| | - Marcela D Torres
- Hematology Department, Cook Children's Medical Center, Fort Worth, TX, USA
| | - Jonathan D Santoro
- Division of Neurology, Children's Hospital Los Angeles, Department of Neurology, Keck School of Medicine at the University of Southern California, Los Angeles, CA USA
| | | | - Carolina Vargas
- Division of Neurology, Department of Pediatrics, The Hospital for Sick Children, Toronto, ON, Canada
| | - Giulia Amico
- Laboratory of Human Genetics, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | - Marta Bertamino
- Physical Medicine and Rehabilitation Unit, IRCCS Instituto Giannina Gaslini, Genoa, Italy
| | - Deepti Nagesh
- Division of Neurology, Children's Hospital Los Angeles, Department of Neurology, Keck School of Medicine at the University of Southern California, Los Angeles, CA USA
| | - Jo Tilley
- Departments of Hematology and Neurology, Cook Children's Medical Center, Fort Worth, TX, USA
| | - Allyson Schenk
- Research Data Science and Analytics Department-Stroke and Thrombosis Program, Cook Children's Medical Center, Fort Worth, TX, USA
| | - Shay Ben-Shachar
- Research Data Science and Analytics Department-Stroke and Thrombosis Program, Cook Children's Medical Center, Fort Worth, TX, USA; Clalit Research Institute, Innovation Division, Clalit Health Services, Ramat Gan, Israel
| | - Patricia L Musolino
- Center for Genomic Medicine, Center for Rare Neurological Disorders, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
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5
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Mercurio SA, Chunn LM, Khursigara G, Nester C, Wray K, Botschen U, Kiel MJ, Rutsch F, Ferreira CR. ENPP1 deficiency: A clinical update on the relevance of individual variants using a locus-specific patient database. Hum Mutat 2022; 43:1673-1705. [PMID: 36150100 DOI: 10.1002/humu.24477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 09/16/2022] [Accepted: 09/21/2022] [Indexed: 01/24/2023]
Abstract
Loss-of-function variants in the ectonucleotide pyrophosphatase/phosphodiesterase family member 1 (ENPP1) cause ENPP1 Deficiency, a rare disorder characterized by pathological calcification, neointimal proliferation, and impaired bone mineralization. The consequence of ENPP1 Deficiency is a broad range of age dependent symptoms and morbidities including cardiovascular complications and 50% mortality in infants, autosomal recessive hypophosphatemic rickets type 2 (ARHR2) in children, and joint pain, osteomalacia and enthesopathies in adults. Recent research continues to add to the growing clinical presentation profile as well as expanding the role of ENPP1 itself. Here we review the current knowledge on the spectrum of clinical and genetic findings of ENPP1 Deficiency reported in patients diagnosed with GACI or ARHR2 phenotypes using a comprehensive database of known ENPP1 variants with associated clinical data. A total of 108 genotypes were identified from 154 patients. Of the 109 ENPP1 variants reviewed, 72.5% were demonstrably disease-causing, a threefold increase in pathogenic/likely pathogenic variants over other databases. There is substantial heterogeneity in disease severity, even among patients with the same variant. The approach to creating a continuously curated database of ENPP1 variants accessible to clinicians is necessary to increase the diagnostic yield of clinical genetic testing and accelerate diagnosis of ENPP1 Deficiency.
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Affiliation(s)
- Stephanie A Mercurio
- Department of Data Science, Curation Division, Genomenon Inc., Ann Arbor, Michigan, USA
| | - Lauren M Chunn
- Department of Scientific Communication and Strategy, Genomenon Inc., Ann Arbor, Michigan, USA
| | - Gus Khursigara
- Department of Medical Affairs, Inozyme Pharma, Boston, Massachusetts, USA
| | - Catherine Nester
- Department of Physician and Patient Strategies, Inozyme Pharma, Boston, Massachusetts, USA
| | - Kathleen Wray
- Department of Medical Affairs, Inozyme Pharma, Boston, Massachusetts, USA
| | - Ulrike Botschen
- Department of General Paediatrics, Muenster University Children's Hospital, Münster, Germany
| | - Mark J Kiel
- Department of Scientific Communication and Strategy, Genomenon Inc., Ann Arbor, Michigan, USA
| | - Frank Rutsch
- Department of General Paediatrics, Muenster University Children's Hospital, Münster, Germany
| | - Carlos R Ferreira
- Metabolic Medicine Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
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6
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Szeri F, Miko A, Navasiolava N, Kaposi A, Verschuere S, Molnar B, Li Q, Terry SF, Boraldi F, Uitto J, van de Wetering K, Martin L, Quaglino D, Vanakker OM, Tory K, Aranyi T. The pathogenic c.1171A>G (p.Arg391Gly) and c.2359G>A (p.Val787Ile) ABCC6 variants display incomplete penetrance causing pseudoxanthoma elasticum in a subset of individuals. Hum Mutat 2022; 43:1872-1881. [PMID: 36317459 PMCID: PMC9772137 DOI: 10.1002/humu.24498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 09/30/2022] [Accepted: 10/24/2022] [Indexed: 11/06/2022]
Abstract
ABCC6 promotes ATP efflux from hepatocytes to bloodstream. ATP is metabolized to pyrophosphate, an inhibitor of ectopic calcification. Pathogenic variants of ABCC6 cause pseudoxanthoma elasticum, a highly variable recessive ectopic calcification disorder. Incomplete penetrance may initiate disease heterogeneity, hence symptoms may not, or differently manifest in carriers. Here, we investigated whether incomplete penetrance is a source of heterogeneity in pseudoxanthoma elasticum. By integrating clinical and genetic data of 589 patients, we created the largest European cohort. Based on allele frequency alterations, we identified two incomplete penetrant pathogenic variants, c.2359G>A (p.Val787Ile) and c.1171A>G (p.Arg391Gly), with 6.5% and 2% penetrance, respectively. However, when penetrant, the c.1171A>G (p.Arg391Gly) manifested a clinically unaltered severity. After applying in silico and in vitro characterization, we suggest that incomplete penetrant variants are only deleterious if a yet unknown interacting partner of ABCC6 is mutated simultaneously. The low penetrance of these variants should be contemplated in genetic counseling.
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Affiliation(s)
- Flora Szeri
- Department of Dermatology and Cutaneous Biology, The Sidney Kimmel Medical College, and The PXE International Center of Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, PA, USA,Institute of Enzymology, Research Centre for Natural Sciences, Budapest, Hungary,Department of Biochemistry, Semmelweis University, Budapest, Hungary
| | - Agnes Miko
- MTA-SE Lendület Nephrogenetic Laboratory, Budapest, Hungary,1st Department of Pediatrics, Semmelweis University, Budapest, Hungary
| | - Nastassia Navasiolava
- PXE Consultation Center, MAGEC Nord Reference Center for Rare Skin Diseases, Angers University Hospital, Angers, France
| | - Ambrus Kaposi
- MTA-SE Lendület Nephrogenetic Laboratory, Budapest, Hungary,1st Department of Pediatrics, Semmelweis University, Budapest, Hungary
| | - Shana Verschuere
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Beatrix Molnar
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, Hungary
| | - Qiaoli Li
- Department of Dermatology and Cutaneous Biology, The Sidney Kimmel Medical College, and The PXE International Center of Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, PA, USA
| | | | - Federica Boraldi
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Jouni Uitto
- Department of Dermatology and Cutaneous Biology, The Sidney Kimmel Medical College, and The PXE International Center of Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, PA, USA
| | - Koen van de Wetering
- Department of Dermatology and Cutaneous Biology, The Sidney Kimmel Medical College, and The PXE International Center of Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, PA, USA
| | - Ludovic Martin
- PXE Consultation Center, MAGEC Nord Reference Center for Rare Skin Diseases, Angers University Hospital, Angers, France
| | - Daniela Quaglino
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy,Interuniversity Consortium for Biotechnologies (CIB), Italy
| | | | - Kalman Tory
- MTA-SE Lendület Nephrogenetic Laboratory, Budapest, Hungary,1st Department of Pediatrics, Semmelweis University, Budapest, Hungary
| | - Tamas Aranyi
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, Hungary,Department of Molecular Biology, Semmelweis University, Budapest, Hungary.,Corresponding author:
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7
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Ramirez-Suarez KI, Cohen SA, Barrera CA, Levine MA, Goldberg DJ, Otero HJ. Longitudinal assessment of vascular calcification in generalized arterial calcification of infancy. Pediatr Radiol 2022; 52:2329-2341. [PMID: 35438330 PMCID: PMC10406615 DOI: 10.1007/s00247-022-05364-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 02/18/2022] [Accepted: 03/18/2022] [Indexed: 10/18/2022]
Abstract
BACKGROUND Generalized arterial calcification of infancy (GACI), also known as idiopathic infantile arterial calcification, is a very uncommon genetic disorder characterized by calcifications and stenoses of large- and medium-size arteries that can lead to end-organ damage. OBJECTIVE To describe changes in imaging findings in 10 children with GACI at a single institution from 2010 to 2021. MATERIALS AND METHODS In this retrospective study we reviewed initial and follow-up body imaging in children with genetic confirmation of GACI at our hospital. All initial images were analyzed for the presence and distribution of arterial calcifications, stenoses and wall thickening/irregularity within the chest, abdomen and pelvis. We compared available follow-up studies to the initial imaging findings. We extracted clinical information including prenatal and postnatal treatment from the children's medical records. RESULTS We evaluated 10 children (five boys) with a diagnosis of GACI. Median age at first body imaging was 8 days (range: 1 day to 5 years). Six children were identified prenatally and four postnatally. Postnatal presentation included cardiac failure, seizures and hypertension. Images in newborns (n = 8) most commonly showed diffuse arterial calcifications (6/8; 75%), while stenoses were less common (2/8; 25%) during this period. Two children were diagnosed after the neonatal period - one in infancy and one during childhood. In total, half the children (5/10; 50%) had arterial stenoses - three cases visualized at first imaging and two identified on follow-up images during infancy. Stenoses had completely resolved in one child (1/5; 20%) at last follow-up. Eight children received prenatal or postnatal treatment or both. All children who received both prenatal and postnatal treatment (n = 4) had completely resolved calcifications at last follow-up. CONCLUSION Children with GACI might have characteristic vascular calcifications at birth that raise the suspicion of this disease. Arterial calcifications decrease or disappear spontaneously or after treatment, but arterial stenoses usually persist. Calcifications and arterial stenoses can be easily identified and followed with non-contrast CT and CT angiography.
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Affiliation(s)
- Karen I Ramirez-Suarez
- Department of Radiology, Children's Hospital of Philadelphia, 3401 Civic Center Blvd., Philadelphia, PA, 19104, USA
| | - Sara A Cohen
- Department of Radiology at Weill Cornell Medicine, New York, NY, USA
| | - Christian A Barrera
- Department of Radiology, Children's Hospital of Philadelphia, 3401 Civic Center Blvd., Philadelphia, PA, 19104, USA
| | - Michael A Levine
- Division of Endocrinology and Diabetes, Center for Bone Health, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
- Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - David J Goldberg
- Division of Cardiology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Hansel J Otero
- Department of Radiology, Children's Hospital of Philadelphia, 3401 Civic Center Blvd., Philadelphia, PA, 19104, USA.
- Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA.
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8
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Pelttari S, Väärämäki S, Vanakker O, Verschuere S, Uusitalo H, Huhtala H, Hinkka T, Pörsti I, Nevalainen PI. Various vascular malformations are prevalent in Finnish pseudoxanthoma elasticum (PXE) patients: a national registry study. Orphanet J Rare Dis 2022; 17:185. [PMID: 35525997 PMCID: PMC9077871 DOI: 10.1186/s13023-022-02341-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 04/26/2022] [Indexed: 11/26/2022] Open
Abstract
Background Pseudoxanthoma elasticum (PXE, OMIM# 264800) is an inborn error of metabolism causing ectopic soft tissue calcification due to low plasma pyrophosphate concentration. We aimed to assess the prevalence of PXE in Finland and to characterize the Finnish PXE population. A nationwide registry search was performed to identify patients with ICD-10 code Q82.84. Information was gathered from available medical records which were requisitioned from hospitals and health centers. Misdiagnosed patients and patients with insufficient records were excluded. Results The prevalence of PXE in Finland was 1:260,000 with equal sex distribution. Patients with high conventional cardiovascular risk had more visual and vascular complications than patients with low risk. Four patients (19%) had at least one vascular malformation. A high proportion (33%) of ABCC6 genotypes were of the common homozygous c.3421C > T, p.Arg1141Ter variant. Nine other homozygous or compound heterozygous allelic variants were found. Conclusions The prevalence of diagnosed PXE appears to be lower in Finland than in estimates from other countries. Decreased visual acuity is the most prevalent complication. We suggest that various vascular malformations may be an unrecognized feature of PXE.
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Affiliation(s)
- Saku Pelttari
- Faculty of Medicine and Life Sciences, Tampere University, Tampere, Finland
| | - Suvi Väärämäki
- Centre for Vascular Surgery and Interventional Radiology, Tampere University Hospital and Tampere University, Tampere, Finland
| | - Olivier Vanakker
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium.,Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
| | - Shana Verschuere
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium.,Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
| | - Hannu Uusitalo
- SILK, Department of Ophthalmology, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland.,Tays Eye Centre, Tampere University Hospital, Tampere, Finland
| | - Heini Huhtala
- Faculty of Social Sciences, Tampere University, Tampere, Finland
| | - Tero Hinkka
- Centre for Vascular Surgery and Interventional Radiology, Tampere University Hospital, Tampere, Finland
| | - Ilkka Pörsti
- Faculty of Medicine and Life Sciences, Tampere University, Tampere, Finland.,Department of Internal Medicine, Tampere University Hospital, Teiskontie 35, 33521, Tampere, Finland
| | - Pasi I Nevalainen
- Department of Internal Medicine, Tampere University Hospital, Teiskontie 35, 33521, Tampere, Finland.
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9
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Jacobs IJ, Cheng Z, Ralph D, O'Brien K, Flaman L, Howe J, Thompson D, Uitto J, Li Q, Sabbagh Y. INZ-701, a recombinant ENPP1 enzyme, prevents ectopic calcification in an Abcc6 -/- mouse model of pseudoxanthoma elasticum. Exp Dermatol 2022; 31:1095-1101. [PMID: 35511611 PMCID: PMC10077110 DOI: 10.1111/exd.14587] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 04/21/2022] [Accepted: 05/03/2022] [Indexed: 11/29/2022]
Abstract
Pseudoxanthoma elasticum (PXE), a heritable multisystem ectopic calcification disorder, is predominantly caused by inactivating mutations in ABCC6. The encoded protein, ABCC6, is a hepatic efflux transporter and a key regulator of extracellular inorganic pyrophosphate (PPi). Recent studies demonstrated that deficiency of plasma PPi, a potent endogenous calcification inhibitor, is the underlying cause of PXE. This study examined whether restoring plasma PPi levels by INZ-701, a recombinant human ENPP1 protein, the principal PPi-generating enzyme, prevents ectopic calcification in an Abcc6-/- mouse model of PXE. Abcc6-/- mice, at 6 weeks of age, the time of earliest stages of ectopic calcification, were injected subcutaneously with INZ-701 at 2 or 10 mg/kg for 2 or 8 weeks. INZ-701 at both doses increased steady-state plasma ENPP1 activity and PPi levels. In the 8-week treatment study, histopathologic examination and quantification of the calcium content in INZ-701-treated Abcc6-/- mice revealed significantly reduced calcification in the muzzle skin containing vibrissae, a biomarker of the calcification process in these mice. The extent of calcification corresponds to the local expression of two calcification inhibitors, osteopontin and fetuin-A. These results suggest that INZ-701 might provide a therapeutic approach for PXE, a disease with high unmet needs and no approved treatment.
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Affiliation(s)
- Ida Joely Jacobs
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, 19107, PA, USA.,PXE International Center of Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, 19107, PA, USA
| | | | - Douglas Ralph
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, 19107, PA, USA.,PXE International Center of Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, 19107, PA, USA.,Genetics, Genomics and Cancer Biology Ph.D. Program, Jefferson College of Life Sciences, Thomas Jefferson University, Philadelphia, 19107, PA, USA
| | | | | | | | | | - Jouni Uitto
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, 19107, PA, USA.,PXE International Center of Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, 19107, PA, USA
| | - Qiaoli Li
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, 19107, PA, USA.,PXE International Center of Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, 19107, PA, USA
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10
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Ralph D, Nitschke Y, Levine MA, Caffet M, Wurst T, Saeidian AH, Youssefian L, Vahidnezhad H, Terry SF, Rutsch F, Uitto J, Li Q. ENPP1 variants in patients with GACI and PXE expand the clinical and genetic heterogeneity of heritable disorders of ectopic calcification. PLoS Genet 2022; 18:e1010192. [PMID: 35482848 PMCID: PMC9089899 DOI: 10.1371/journal.pgen.1010192] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 05/10/2022] [Accepted: 04/05/2022] [Indexed: 12/17/2022] Open
Abstract
Pseudoxanthoma elasticum (PXE) and generalized arterial calcification of infancy (GACI) are clinically distinct genetic entities of ectopic calcification associated with differentially reduced circulating levels of inorganic pyrophosphate (PPi), a potent endogenous inhibitor of calcification. Variants in ENPP1, the gene mutated in GACI, have not been associated with classic PXE. Here we report the clinical, laboratory, and molecular evaluations of ten GACI and two PXE patients from five and two unrelated families registered in GACI Global and PXE International databases, respectively. All patients were found to carry biallelic variants in ENPP1. Among ten ENPP1 variants, one homozygous variant demonstrated uniparental disomy inheritance. Functional assessment of five previously unreported ENPP1 variants suggested pathogenicity. The two PXE patients, currently 57 and 27 years of age, had diagnostic features of PXE and had not manifested the GACI phenotype. The similarly reduced PPi plasma concentrations in the PXE and GACI patients in our study correlate poorly with their disease severity. This study demonstrates that in addition to GACI, ENPP1 variants can cause classic PXE, expanding the clinical and genetic heterogeneity of heritable ectopic calcification disorders. Furthermore, the results challenge the current prevailing concept that plasma PPi is the only factor governing the severity of ectopic calcification. Biallelic inactivating mutations in the ENPP1 gene cause generalized arterial calcification of infancy (GACI), a frequently fatal disease characterized by infantile onset of widespread arterial calcification and/or narrowing of large and medium-sized vessels often resulting in the early demise of affected individuals. Significantly reduced, almost zero plasma levels of a potent and endogenous calcification inhibitor, inorganic pyrophosphate (PPi), is thought to be the underlying cause of vascular calcification in GACI. Mutations in ENPP1 have not been found in patients with pseudoxanthoma elasticum (PXE), another genetic multisystem ectopic calcification disorder caused by mutations in the ABCC6 gene. This study reports that ENPP1 mutations can also cause PXE with more favorable clinical outcomes. In addition, it was previously thought that plasma PPi levels correlate with vascular calcification severity. However, we here show that vascular calcification severity does not correlate with plasma PPi levels. The results suggest that in addition to PPi, the long-believed determinant of ectopic calcification, additional mechanisms may be at play in regulating ectopic calcification.
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Affiliation(s)
- Douglas Ralph
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, and Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
- Genetics, Genomics and Cancer Biology Ph.D. Program, Jefferson College of Life Sciences, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
- PXE International Center of Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | | | - Michael A. Levine
- Division of Endocrinology and Diabetes, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Matthew Caffet
- PXE International, Inc., Damascus, Maryland, United States of America
| | - Tamara Wurst
- PXE International, Inc., Damascus, Maryland, United States of America
| | - Amir Hossein Saeidian
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, and Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
- Genetics, Genomics and Cancer Biology Ph.D. Program, Jefferson College of Life Sciences, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Leila Youssefian
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, and Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Hassan Vahidnezhad
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, and Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Sharon F. Terry
- PXE International, Inc., Damascus, Maryland, United States of America
| | - Frank Rutsch
- Münster University Children’s Hospital, Münster, Germany
| | - Jouni Uitto
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, and Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
- PXE International Center of Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Qiaoli Li
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, and Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
- PXE International Center of Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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11
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Yunfeng L, Tongyan H, Jing W, Xiaomei T. Case Report: A Novel Genetic Mutation Causes Idiopathic Infantile Arterial Calcification in Preterm Infants. Front Genet 2022; 12:763916. [PMID: 35003211 PMCID: PMC8733597 DOI: 10.3389/fgene.2021.763916] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 12/07/2021] [Indexed: 01/01/2023] Open
Abstract
Idiopathic infantile arterial calcification (IIAC), also known as generalized arterial calcification of infancy (GACI), is a heritable ectopic mineralization disorder that results in diffuse arterial calcifications and or stenosis, which are attributed to mutations in the ENPP1 gene. In this case study, we report the development of IIAC in a 2-month-old male preterm infant. The patient presented with severe hypertension and seizures, which revealed diffused calcifications and c.130C > T and c.1112A > T mutations in the ENPP1 gene. With biphosphonate, antihypertensive, and control epilepsy therapy, his blood pressure was maintained at 110–120/50–60 mmHg. Intellectual motor development retardation was anticipated in this patient. To the best of our knowledge, this is the first case in which a novel c.130C > T mutation in the ENPP1 gene has been identified, and the administration of bisphosphonates to patients with IIAC has been assessed.
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Affiliation(s)
- Liu Yunfeng
- Department of Pediatrics, Peking University Third Hospital, Beijing, China
| | - Han Tongyan
- Department of Pediatrics, Peking University Third Hospital, Beijing, China
| | - Wang Jing
- Department of Pediatrics, Peking University Third Hospital, Beijing, China
| | - Tong Xiaomei
- Department of Pediatrics, Peking University Third Hospital, Beijing, China
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12
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Kozák E, Fülöp K, Tőkési N, Rao N, Li Q, Terry SF, Uitto J, Zhang X, Becker C, Váradi A, Pomozi V. Oral supplementation of inorganic pyrophosphate in pseudoxanthoma elasticum. Exp Dermatol 2021; 31:548-555. [PMID: 34758173 DOI: 10.1111/exd.14498] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 10/29/2021] [Accepted: 11/06/2021] [Indexed: 01/19/2023]
Abstract
Pseudoxanthoma elasticum (PXE; OMIM 264800) is a rare heritable multisystem disorder, characterized by ectopic mineralization affecting elastic fibres in the skin, eyes and the cardiovascular system. Skin findings often lead to early diagnosis of PXE, but currently, no specific treatment exists to counteract the progression of symptoms. PXE belongs to a group of Mendelian calcification disorders linked to pyrophosphate metabolism, which also includes generalized arterial calcification of infancy (GACI) and arterial calcification due to CD73 deficiency (ACDC). Inactivating mutations in ABCC6, ENPP1 and NT5E are the genetic cause of these diseases, respectively, and all of them result in reduced inorganic pyrophosphate (PPi ) concentration in the circulation. Although PPi is a strong inhibitor of ectopic calcification, oral supplementation therapy was initially not considered because of its low bioavailability. Our earlier work however demonstrated that orally administered pyrophosphate inhibits ectopic calcification in the animal models of PXE and GACI, and that orally given Na4 P2 O7 is absorbed in humans. Here, we report that gelatin-encapsulated Na2 H2 P2 O7 has similar absorption properties in healthy volunteers and people affected by PXE. The sodium-free K2 H2 P2 O7 form resulted in similar uptake in healthy volunteers and inhibited calcification in Abcc6-/- mice as effectively as its sodium counterpart. Novel pyrophosphate compounds showing higher bioavailability in mice were also identified. Our results provide an important step towards testing oral PPi in clinical trials in PXE, or potentially any condition accompanied by ectopic calcification including diabetes, chronic kidney disease or ageing.
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Affiliation(s)
- Eszter Kozák
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences Centre of Excellence, Budapest, Hungary
| | - Krisztina Fülöp
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences Centre of Excellence, Budapest, Hungary
| | - Natália Tőkési
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences Centre of Excellence, Budapest, Hungary
| | - Nidhi Rao
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences Centre of Excellence, Budapest, Hungary
| | - Qiaoli Li
- Department of Dermatology and Cutaneous Biology, PXE International Center of Excellence in Research and Clinical Care, Sidney Kimmel Medicine College, Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Sharon F Terry
- PXE International, Washington, District of Columbia, USA
| | - Jouni Uitto
- Department of Dermatology and Cutaneous Biology, PXE International Center of Excellence in Research and Clinical Care, Sidney Kimmel Medicine College, Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Xiaoming Zhang
- Theratrophix, Sunnyvale, California, USA.,Pyrogenyx, Sunnyvale, California, USA
| | - Cyrus Becker
- Theratrophix, Sunnyvale, California, USA.,Pyrogenyx, Sunnyvale, California, USA
| | - András Váradi
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences Centre of Excellence, Budapest, Hungary
| | - Viola Pomozi
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences Centre of Excellence, Budapest, Hungary
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13
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Abstract
ABC transporters are a large family of membrane proteins that transport chemically diverse substrates across the cell membrane. Disruption of transport mechanisms mediated by ABC transporters causes the development of various diseases, including atherosclerosis. Methods: A bioinformatic analysis of a dataset from Gene Expression Omnibus (GEO) was performed. A GEO dataset containing data on gene expression levels in samples of atherosclerotic lesions and control arteries without atherosclerotic lesions from carotid, femoral, and infrapopliteal arteries was used for analysis. To evaluate differentially expressed genes, a bioinformatic analysis was performed in comparison groups using the limma package in R (v. 4.0.2) and the GEO2R and Phantasus tools (v. 1.11.0). Results: The obtained data indicate the differential expression of many ABC transporters belonging to different subfamilies. The differential expressions of ABC transporter genes involved in lipid transport, mechanisms of multidrug resistance, and mechanisms of ion exchange are shown. Differences in the expression of transporters in tissue samples from different arteries are established. Conclusions: The expression of ABC transporter genes demonstrates differences in atherosclerotic samples and normal arteries, which may indicate the involvement of transporters in the pathogenesis of atherosclerosis.
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14
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Ferreira CR, Kintzinger K, Hackbarth ME, Botschen U, Nitschke Y, Mughal MZ, Baujat G, Schnabel D, Yuen E, Gahl WA, Gafni RI, Liu Q, Huertas P, Khursigara G, Rutsch F. Ectopic Calcification and Hypophosphatemic Rickets: Natural History of ENPP1 and ABCC6 Deficiencies. J Bone Miner Res 2021; 36:2193-2202. [PMID: 34355424 PMCID: PMC8595532 DOI: 10.1002/jbmr.4418] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 07/29/2021] [Accepted: 08/01/2021] [Indexed: 02/06/2023]
Abstract
Generalized arterial calcification of infancy (GACI) is a rare disorder caused by ENPP1 or ABCC6 variants. GACI is characterized by low pyrophosphate, arterial calcification, and high mortality during the first year of life, but the natural course and possible differences between the causative genes remain unknown. In all, 247 individual records for patients with GACI (from birth to 58.3 years of age) across 19 countries were reviewed. Overall mortality was 54.7% (13.4% in utero or stillborn), with a 50.4% probability of death before the age of 6 months (critical period). Contrary to previous publications, we found that bisphosphonate treatment had no survival benefit based on a start-time matched analysis and inconclusive results when initiated within 2 weeks of birth. Despite a similar prevalence of GACI phenotypes between ENPP1 and ABCC6 deficiencies, including arterial calcification (77.2% and 89.5%, respectively), organ calcification (65.8% and 84.2%, respectively), and cardiovascular complications (58.4% and 78.9%, respectively), mortality was higher for ENPP1 versus ABCC6 variants (40.5% versus 10.5%, respectively; p = 0.0157). Higher prevalence of rickets was reported in 70.8% of surviving affected individuals with ENPP1 compared with that of ABCC6 (11.8%; p = 0.0001). Eleven affected individuals presenting with rickets and without a GACI diagnosis, termed autosomal recessive hypophosphatemic rickets type 2 (ARHR2), all had confirmed ENPP1 variants. Approximately 70% of these patients demonstrated evidence of ectopic calcification or complications similar to those seen in individuals with GACI, which shows that ARHR2 is not a distinct condition from GACI but represents part of the spectrum of ENPP1 deficiency. Overall, this study identified an early mortality risk in GACI patients despite attempts to treat with bisphosphonates, high prevalence of rickets almost exclusive to ENPP1 deficiency, and a spectrum of heterogenous calcification and multiple organ complications with both ENPP1 and ABCC6 variants, which suggests an overlapping pathology. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR). This article has been contributed to by US Government employees and their work is in the public domain in the USA.
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Affiliation(s)
- Carlos R Ferreira
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Kristina Kintzinger
- Department of General Pediatrics, Münster University Children's Hospital, Münster, Germany
| | - Mary E Hackbarth
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Ulrike Botschen
- Department of General Pediatrics, Münster University Children's Hospital, Münster, Germany
| | - Yvonne Nitschke
- Department of General Pediatrics, Münster University Children's Hospital, Münster, Germany
| | - M Zulf Mughal
- Department of Paediatric Endocrinology, Royal Manchester Children's Hospital, Manchester, UK
| | - Genevieve Baujat
- Centre de Référence Maladies Osseuses Constitutionnelles (CR MOC) et Filière OSCAR, Département de Génétique, Hôpital Necker-Enfants Malades, Paris, France
| | - Dirk Schnabel
- Center for Chronically Sick Children, Pediatric Endocrinology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Eric Yuen
- Inozyme Pharma, Inc., Boston, MA, USA
| | - William A Gahl
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Rachel I Gafni
- National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
| | - Qing Liu
- Quantitative & Regulatory Medical Science, LLC, Long Valley, NJ, USA
| | | | | | - Frank Rutsch
- Department of General Pediatrics, Münster University Children's Hospital, Münster, Germany
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15
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Kowal L, Huang J, Luo H, Singh J, Snook AE, Uitto J, Li Q. Functional Assessment of Missense Variants in the ABCC6 Gene Implicated in Pseudoxanthoma Elasticum, a Heritable Ectopic Mineralization Disorder. J Invest Dermatol 2021; 142:1085-1093. [PMID: 34597610 DOI: 10.1016/j.jid.2021.08.435] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 08/16/2021] [Accepted: 08/25/2021] [Indexed: 12/14/2022]
Abstract
Pseudoxanthoma elasticum, a heritable multisystem ectopic mineralization disorder, is caused by inactivating mutations in the ABCC6 gene. The encoded protein, ABCC6, a transmembrane transporter, has a specialized efflux function in hepatocytes by contributing to plasma levels of inorganic pyrophosphate, a potent inhibitor of mineralization in soft connective tissues. Reduced plasma inorganic pyrophosphate levels underlie the ectopic mineralization in pseudoxanthoma elasticum. In this study, we characterized the pathogenicity of three human ABCC6 missense variants using an adenovirus-mediated liver-specific ABCC6 transgene expression system in an Abcc6-/- mouse model of pseudoxanthoma elasticum. Variants p.L420V and p.R1064W were found benign because they had abundance and plasma membrane localization in hepatocytes similar to the wild-type human ABCC6 transgene, normalized plasma inorganic pyrophosphate levels, and prevented mineralization in the dermal sheath of vibrissae in muzzle skin, a phenotypic hallmark in the Abcc6-/- mice. In contrast, p.S400F was shown to be pathogenic because it failed to normalize plasma inorganic pyrophosphate levels and had no effect on ectopic mineralization despite its normal expression and proper localization in hepatocytes. These results showed that adenovirus-mediated hepatic ABCC6 expression in Abcc6-/- mice can provide a model system to effectively elucidate the multifaceted functional consequences of human ABCC6 missense variants identified in patients with pseudoxanthoma elasticum.
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Affiliation(s)
- Luke Kowal
- PXE International Center of Excellence in Research and Clinical Care, Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Jianhe Huang
- PXE International Center of Excellence in Research and Clinical Care, Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Hongbin Luo
- PXE International Center of Excellence in Research and Clinical Care, Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania, USA; Department of Dermatology, The First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, China
| | - Jagmohan Singh
- Department of Pharmacology and Experimental Therapeutics, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Adam E Snook
- Department of Pharmacology and Experimental Therapeutics, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Jouni Uitto
- PXE International Center of Excellence in Research and Clinical Care, Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Qiaoli Li
- PXE International Center of Excellence in Research and Clinical Care, Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania, USA.
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16
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Ferreira CR, Kavanagh D, Oheim R, Zimmerman K, Stürznickel J, Li X, Stabach P, Rettig RL, Calderone L, MacKichan C, Wang A, Hutchinson HA, Nelson T, Tommasini SM, von Kroge S, Fiedler IA, Lester ER, Moeckel GW, Busse B, Schinke T, Carpenter TO, Levine MA, Horowitz MC, Braddock DT. Response of the ENPP1-Deficient Skeletal Phenotype to Oral Phosphate Supplementation and/or Enzyme Replacement Therapy: Comparative Studies in Humans and Mice. J Bone Miner Res 2021; 36:942-955. [PMID: 33465815 PMCID: PMC8739051 DOI: 10.1002/jbmr.4254] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 01/11/2021] [Accepted: 01/15/2021] [Indexed: 12/14/2022]
Abstract
Inactivating mutations in human ecto-nucleotide pyrophosphatase/phosphodiesterase-1 (ENPP1) may result in early-onset osteoporosis (EOOP) in haploinsufficiency and autosomal recessive hypophosphatemic rickets (ARHR2) in homozygous deficiency. ARHR2 patients are frequently treated with phosphate supplementation to ameliorate the rachitic phenotype, but elevating plasma phosphorus concentrations in ARHR2 patients may increase the risk of ectopic calcification without increasing bone mass. To assess the risks and efficacy of conventional ARHR2 therapy, we performed comprehensive evaluations of ARHR2 patients at two academic medical centers and compared their skeletal and renal phenotypes with ENPP1-deficient Enpp1asj/asj mice on an acceleration diet containing high phosphate treated with recombinant murine Enpp1-Fc. ARHR2 patients treated with conventional therapy demonstrated improvements in rickets, but all adults and one adolescent analyzed continued to exhibit low bone mineral density (BMD). In addition, conventional therapy was associated with the development of medullary nephrocalcinosis in half of the treated patients. Similar to Enpp1asj/asj mice on normal chow and to patients with mono- and biallelic ENPP1 mutations, 5-week-old Enpp1asj/asj mice on the high-phosphate diet exhibited lower trabecular bone mass, reduced cortical bone mass, and greater bone fragility. Treating the Enpp1asj/asj mice with recombinant Enpp1-Fc protein between weeks 2 and 5 normalized trabecular bone mass, normalized or improved bone biomechanical properties, and prevented the development of nephrocalcinosis and renal failure. The data suggest that conventional ARHR2 therapy does not address low BMD inherent in ENPP1 deficiency, and that ENPP1 enzyme replacement may be effective for correcting low bone mass in ARHR2 patients without increasing the risk of nephrocalcinosis. © 2021 American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Carlos R Ferreira
- Medical Genomics and Metabolic Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Dillon Kavanagh
- Department of Pathology, Yale University School of Medicine, New Haven, CT, USA
| | - Ralf Oheim
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Kristin Zimmerman
- Department of Pathology, Yale University School of Medicine, New Haven, CT, USA
| | - Julian Stürznickel
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Xiaofeng Li
- Department of Pathology, Yale University School of Medicine, New Haven, CT, USA
| | - Paul Stabach
- Department of Pathology, Yale University School of Medicine, New Haven, CT, USA
| | - R Luke Rettig
- Department of Pathology, Yale University School of Medicine, New Haven, CT, USA
| | - Logan Calderone
- Department of Pathology, Yale University School of Medicine, New Haven, CT, USA
| | - Colin MacKichan
- Department of Pathology, Yale University School of Medicine, New Haven, CT, USA
| | - Aaron Wang
- Department of Pathology, Yale University School of Medicine, New Haven, CT, USA
| | - Hunter A Hutchinson
- Department of Pathology, Yale University School of Medicine, New Haven, CT, USA
| | - Tracy Nelson
- Department of Orthopaedics and Rehabilitation, Yale University School of Medicine, New Haven, CT, USA
| | - Steven M Tommasini
- Department of Orthopaedics and Rehabilitation, Yale University School of Medicine, New Haven, CT, USA
| | - Simon von Kroge
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Imke Ak Fiedler
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Ethan R Lester
- Department of Pathology, Yale University School of Medicine, New Haven, CT, USA
| | - Gilbert W Moeckel
- Department of Pathology, Yale University School of Medicine, New Haven, CT, USA
| | - Björn Busse
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Thorsten Schinke
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Thomas O Carpenter
- Department of Pediatrics, Yale University School of Medicine, New Haven, CT, USA
| | - Michael A Levine
- Department of Pediatrics, University of Pennsylvania Perlman School of Medicine, Philadelphia, PA, USA.,Division of Endocrinology and Diabetes and Center for Bone Health, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Mark C Horowitz
- Department of Orthopaedics and Rehabilitation, Yale University School of Medicine, New Haven, CT, USA
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17
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Steyaert W, Verschuere S, Coucke PJ, Vanakker OM. Comprehensive validation of a diagnostic strategy for sequencing genes with one or multiple pseudogenes using pseudoxanthoma elasticum as a model. J Genet Genomics 2021; 48:289-299. [PMID: 34049798 DOI: 10.1016/j.jgg.2021.02.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 02/03/2021] [Accepted: 02/09/2021] [Indexed: 10/21/2022]
Abstract
Pseudogenes are frequently encountered noncoding sequences with a high sequence similarity to their protein-coding paralogue. For this reason, their presence is often considered troublesome in molecular diagnostics. In pseudoxanthoma elasticum (PXE), a disease predominantly caused by mutations in ATP-binding cassette family C member 6 (ABCC6), the presence of two pseudogenes complicates the analysis of sequence data. With whole-exome sequencing (WES) becoming the standard of care in molecular diagnostics, we wanted to evaluate whether this technique is as reliable as gene-specific targeted enrichment analysis for the analysis of ABCC6. We established a PCR-based targeted enrichment and next-generation sequencing testing approach and demonstrated that the ABCC6-specific enrichment combined with the applied mapping algorithm overcomes the complication of ABCC6 pseudogene aspecificities, contrary to WES. We propose a time- and cost-efficient diagnostic strategy for comprehensive and accurate molecular genetic testing of PXE, which is highly automatable.
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Affiliation(s)
- Wouter Steyaert
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium; Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
| | - Shana Verschuere
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium; Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
| | - Paul J Coucke
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium; Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
| | - Olivier M Vanakker
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium; Department of Biomolecular Medicine, Ghent University, Ghent, Belgium.
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18
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Jacobs IJ, Li D, Ivarsson ME, Uitto J, Li Q. A phytic acid analogue INS-3001 prevents ectopic calcification in an Abcc6 -/- mouse model of pseudoxanthoma elasticum. Exp Dermatol 2021; 30:853-858. [PMID: 33523493 DOI: 10.1111/exd.14288] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 12/07/2020] [Accepted: 01/15/2021] [Indexed: 12/17/2022]
Abstract
Pseudoxanthoma elasticum (PXE), a prototype of heritable ectopic calcification disorders, affects the skin, eyes and the cardiovascular system due to inactivating mutations in the ABCC6 gene. There is no effective treatment for the systemic manifestations of PXE. In this study, the efficacy of INS-3001, an analogue of phytic acid, was tested for inhibition of ectopic calcification in an Abcc6-/- mouse model of PXE. In prevention study, Abcc6-/- mice, at 6 weeks of age, the time of onset of ectopic calcification, were treated with INS-3001 with 0.16, 0.8, 4, 20 or 100 mg/kg/day administered by subcutaneous implantation of osmotic pumps, as well as 4 mg/kg/day by subcutaneous injection thrice weekly or 14, 4 and 0.8 mg/kg/day once weekly subcutaneous injection. Mice were necropsied at 12 weeks of age. Histologic examination and quantitative calcium assay revealed that mice receiving 6 weeks of continuous INS-3001 administration via osmotic pumps showed dose-dependent inhibition of muzzle skin calcification with complete response at 4 mg/kg/day and a minimum effective dose at 0.8 mg/kg/day. INS-3001 plasma concentrations were dose-dependent and largely consistent during treatment for each dose. thrice weekly and once weekly subcutaneous injections of INS-3001 also prevented calcification. In established disease study, 12-week-old Abcc6-/- mice with extensive calcification were continuously administered INS-3001 at 4 mg/kg/day for a follow-up of 12 weeks. INS-3001 treatment was found to stabilize existing calcification that had developed at start of treatment. These results suggest that INS-3001 may provide a promising preventive treatment strategy for PXE, a currently intractable ectopic calcification disorder.
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Affiliation(s)
- Ida Joely Jacobs
- Department of Dermatology and Cutaneous Biology, PXE International Center of Excellence in Research and Clinical Care, Jefferson Institute of Molecular Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Diana Li
- Department of Dermatology and Cutaneous Biology, PXE International Center of Excellence in Research and Clinical Care, Jefferson Institute of Molecular Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | | | - Jouni Uitto
- Department of Dermatology and Cutaneous Biology, PXE International Center of Excellence in Research and Clinical Care, Jefferson Institute of Molecular Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Qiaoli Li
- Department of Dermatology and Cutaneous Biology, PXE International Center of Excellence in Research and Clinical Care, Jefferson Institute of Molecular Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
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19
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Maulding ND, Kavanagh D, Zimmerman K, Coppola G, Carpenter TO, Jue NK, Braddock DT. Genetic pathways disrupted by ENPP1 deficiency provide insight into mechanisms of osteoporosis, osteomalacia, and paradoxical mineralization. Bone 2021; 142:115656. [PMID: 32980560 PMCID: PMC7744330 DOI: 10.1016/j.bone.2020.115656] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 09/17/2020] [Accepted: 09/18/2020] [Indexed: 12/16/2022]
Abstract
Ectonucleotide phosphatase/phosphodiesterase 1 (ENPP1) deficiency results in either lethal arterial calcifications ('Generalized Arterial Calcification of Infancy' - GACI), phosphate wasting rickets ('Autosomal Recessive Hypophosphatemic Rickets type 2' - ARHR2), early onset osteoporosis, or progressive spinal rigidity ('Ossification of the Posterior Longitudinal Ligament' - OPLL). As ENPP1 generates a strong endogenous mineralization inhibitor - extracellular pyrophosphate (PPi) - ENPP1 deficiency should not result in reduced bone volume, and therefore the mechanism ENPP1 associated osteoporosis is not apparent given current understanding of the enzyme's function. To investigate genetic pathways driving the skeletal phenotype of ENPP1 deficiency we compared gene expression in Enpp1asj/asj mice and WT sibling pairs by RNAseq and qPCR in whole bones, and in the liver and kidney by qPCR, directly correlating gene expression with measures of bone microarchitectural and biomechanical phenotypes. Unbiased analysis of the differentially expressed genes compared to relevant human disease phenotypes revealed that Enpp1asj/asj mice exhibit strong signatures of osteoporosis, ARHR2 and OPLL. We found that ENPP1 deficient mice exhibited reduced gene transcription of Wnt ligands in whole bone and increased transcription of soluble Wnt inhibitors in the liver and kidney, suggestive of multiorgan inhibition of Wnt activity. Consistent with Wnt suppression in bone, Collagen gene pathways in bone were significantly decreased and Fgf23 was significantly increased, all of which directly correlated with bone microarchitectural defects and fracture risk in Enpp1asj/asj mice. Moreover, the bone findings in 10-week old mice correlated with Enpp1 transcript counts but not plasma [PPi], suggesting that the skeletal phenotype at 10 weeks is driven by catalytically independent ENPP1 function. In contrast, the bone findings in 23-week Enpp1asj/asj mice strongly correlated with plasma PPi, suggesting that chronically low PPi drives the skeletal phenotype in older mice. Finally, correlation between Enpp1 and Fgf23 transcription suggested ENPP1 regulation of Fgf23, which we confirmed by dosing Enpp1asj/asj mice with soluble ENPP1-Fc and observing suppression of intact plasma FGF23 and ALP. In summary, our findings suggest that osteoporosis associated with ENPP1 deficiency involves the suppression of Wnt via catalytically independent Enpp1 pathways, and validates Enpp1asj/asj mice as tools to better understand OPLL and Paradoxical Mineralization Disorders.
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Affiliation(s)
- Nathan D Maulding
- Department of Pathology, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Dillon Kavanagh
- Department of Pathology, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Kristin Zimmerman
- Department of Pathology, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Gianfilippo Coppola
- Department of Pathology, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Thomas O Carpenter
- Department of Pediatrics at Yale University School of Medicine, New Haven, CT 06510, USA
| | - Nathaniel K Jue
- Department of Biology and Chemistry, California State University, Monterey Bay, CA, USA.
| | - Demetrios T Braddock
- Department of Pathology, Yale University School of Medicine, New Haven, CT 06510, USA.
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20
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Luo H, Li Q, Cao Y, Uitto J. Therapeutics Development for Pseudoxanthoma Elasticum and Related Ectopic Mineralization Disorders: Update 2020. J Clin Med 2020; 10:E114. [PMID: 33396306 PMCID: PMC7795895 DOI: 10.3390/jcm10010114] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 12/23/2020] [Accepted: 12/28/2020] [Indexed: 12/11/2022] Open
Abstract
Pseudoxanthoma elasticum (PXE), the prototype of heritable ectopic mineralization disorders, manifests with deposition of calcium hydroxyapatite crystals in the skin, eyes and arterial blood vessels. This autosomal recessive disorder, due to mutations in ABCC6, is usually diagnosed around the second decade of life. In the spectrum of heritable ectopic mineralization disorders are also generalized arterial calcification of infancy (GACI), with extremely severe arterial calcification diagnosed by prenatal ultrasound or perinatally, and arterial calcification due to CD73 deficiency (ACDC) manifesting with arterial and juxta-articular mineralization in the elderly; the latter disorders are caused by mutations in ENPP1 and NT5E, respectively. The unifying pathomechanistic feature in these three conditions is reduced plasma levels of inorganic pyrophosphate (PPi), a powerful endogenous inhibitor of ectopic mineralization. Several on-going attempts to develop treatments for these conditions, either with the goal to normalize PPi plasma levels or by means of preventing calcium hydroxyapatite deposition independent of PPi, are in advanced preclinical levels or in early clinical trials. This overview summarizes the prospects of treatment development for ectopic mineralization disorders, with PXE, GACI and ACDC as the target diseases, from the 2020 vantage point.
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Affiliation(s)
- Hongbin Luo
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College and the PXE International Center for Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, PA 19107, USA; (H.L.); (Q.L.)
- Department of Dermatology, The First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou 310006, China;
| | - Qiaoli Li
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College and the PXE International Center for Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, PA 19107, USA; (H.L.); (Q.L.)
- Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Yi Cao
- Department of Dermatology, The First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou 310006, China;
| | - Jouni Uitto
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College and the PXE International Center for Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, PA 19107, USA; (H.L.); (Q.L.)
- Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, PA 19107, USA
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21
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Molecular Genetics and Modifier Genes in Pseudoxanthoma Elasticum, a Heritable Multisystem Ectopic Mineralization Disorder. J Invest Dermatol 2020; 141:1148-1156. [PMID: 33341249 DOI: 10.1016/j.jid.2020.10.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 10/19/2020] [Accepted: 10/23/2020] [Indexed: 01/08/2023]
Abstract
In the past two decades, there has been great progress in identifying the molecular basis and pathomechanistic details in pseudoxanthoma elasticum (PXE), a heritable multisystem ectopic mineralization disorder. Although the identification of pathogenic variants in ABCC6 has been critical for understanding the disease process, genetic modifiers have been disclosed that explain the phenotypic heterogeneity of PXE. Adding to the genetic complexity of PXE are PXE-like phenotypes caused by pathogenic variants in other ectopic mineralization-associated genes. This review summarizes the current knowledge of the genetics and candidate modifier genes in PXE, a multifactorial disease at the genome-environment interface.
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22
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Schlesinger PH, Braddock DT, Larrouture QC, Ray EC, Riazanski V, Nelson DJ, Tourkova IL, Blair HC. Phylogeny and chemistry of biological mineral transport. Bone 2020; 141:115621. [PMID: 32858255 PMCID: PMC7771281 DOI: 10.1016/j.bone.2020.115621] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 08/24/2020] [Accepted: 08/24/2020] [Indexed: 02/08/2023]
Abstract
Three physiologically mineralizing tissues - teeth, cartilage and bone - have critical common elements and important evolutionary relationships. Phylogenetically the most ancient densely mineralized tissue is teeth. In jawless fishes without skeletons, tooth formation included epithelial transport of phosphates, a process echoed later in bone physiology. Cartilage and mineralized cartilage are skeletal elements separate from bone, but with metabolic features common to bone. Cartilage mineralization is coordinated with high expression of tissue nonspecific alkaline phosphatase and PHOSPHO1 to harvest available phosphate esters and support mineralization of collagen secreted locally. Mineralization in true bone results from stochastic nucleation of hydroxyapatite crystals within the cross-linked collagen fibrils. Mineral accumulation in dense collagen is, at least in major part, mediated by amorphous aggregates - often called Posner clusters - of calcium and phosphate that are small enough to diffuse into collagen fibrils. Mineral accumulation in membrane vesicles is widely suggested, but does not correlate with a definitive stage of mineralization. Conversely mineral deposition at non-physiologic sites where calcium and phosphate are adequate has been shown to be regulated in large part by pyrophosphate. All of these elements are present in vertebrate bone metabolism. A key biological element of bone formation is an epithelial-like cellular organization which allows control of phosphate, calcium and pH during mineralization.
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Affiliation(s)
- Paul H Schlesinger
- Dept of Cell Biology, Washington University, Saint Louis, MO, United States of America
| | - Demetrios T Braddock
- Dept. of Pathology, Yale New Haven Hospital, 310 Cedar Street, New Haven, CT, United States of America
| | - Quitterie C Larrouture
- Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Botnar Research Centre, Windmill Road, Oxford OX3 7LD, UK
| | - Evan C Ray
- Renal Electrolyte Division, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Vladimir Riazanski
- Dept of Neurobiology, Pharmacology & Physiology, University of Chicago, Chicago, IL, United States of America
| | - Deborah J Nelson
- Dept of Neurobiology, Pharmacology & Physiology, University of Chicago, Chicago, IL, United States of America
| | - Irina L Tourkova
- Veteran's Affairs Medical Center, Pittsburgh PA and Department of Pathology, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Harry C Blair
- Veteran's Affairs Medical Center, Pittsburgh PA and Department of Pathology, University of Pittsburgh, Pittsburgh, PA, United States of America.
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23
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Verschuere S, Van Gils M, Nollet L, Vanakker OM. From membrane to mineralization: the curious case of the ABCC6 transporter. FEBS Lett 2020; 594:4109-4133. [PMID: 33131056 DOI: 10.1002/1873-3468.13981] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 10/12/2020] [Accepted: 10/16/2020] [Indexed: 12/13/2022]
Abstract
ATP-binding cassette subfamily C member 6 gene/protein (ABCC6) is an ATP-dependent transmembrane transporter predominantly expressed in the liver and the kidney. ABCC6 first came to attention in human medicine when it was discovered in 2000 that mutations in its encoding gene, ABCC6, caused the autosomal recessive multisystemic mineralization disease pseudoxanthoma elasticum (PXE). Since then, the physiological and pathological roles of ABCC6 have been the subject of intense research. In the last 20 years, significant findings have clarified ABCC6 structure as well as its physiological role in mineralization homeostasis in humans and animal models. Yet, several facets of ABCC6 biology remain currently incompletely understood, ranging from the precise nature of its substrate(s) to the increasingly complex molecular genetics. Nonetheless, advances in our understanding of pathophysiological mechanisms causing mineralization lead to several treatment options being suggested or already tested in pilot clinical trials for ABCC6 deficiency. This review highlights current knowledge of ABCC6 and the challenges ahead, particularly the attempts to translate basic science into clinical practice.
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Affiliation(s)
- Shana Verschuere
- Center for Medical Genetics, Ghent University Hospital, Belgium.,Department of Biomolecular Medicine, Ghent University, Belgium.,Ectopic Mineralization Research Group Ghent, Ghent, Belgium
| | - Matthias Van Gils
- Center for Medical Genetics, Ghent University Hospital, Belgium.,Department of Biomolecular Medicine, Ghent University, Belgium.,Ectopic Mineralization Research Group Ghent, Ghent, Belgium
| | - Lukas Nollet
- Center for Medical Genetics, Ghent University Hospital, Belgium.,Department of Biomolecular Medicine, Ghent University, Belgium.,Ectopic Mineralization Research Group Ghent, Ghent, Belgium
| | - Olivier M Vanakker
- Center for Medical Genetics, Ghent University Hospital, Belgium.,Department of Biomolecular Medicine, Ghent University, Belgium.,Ectopic Mineralization Research Group Ghent, Ghent, Belgium
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24
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Rutsch F, Buers I, Nitschke Y. Hereditary Disorders of Cardiovascular Calcification. Arterioscler Thromb Vasc Biol 2020; 41:35-47. [PMID: 33176451 DOI: 10.1161/atvbaha.120.315577] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Arterial calcification is a common phenomenon in the elderly, in patients with atherosclerosis or renal failure and in diabetes. However, when present in very young individuals, it is likely to be associated with an underlying hereditary disorder of arterial calcification. Here, we present an overview of the few monogenic disorders presenting with early-onset cardiovascular calcification. These disorders can be classified according to the function of the respective disease gene into (1) disorders caused by an altered purine and phosphate/pyrophosphate metabolism, (2) interferonopathies, and (3) Gaucher disease. The finding of arterial calcification in early life should alert the clinician and prompt further genetic work-up to define the underlying genetic defect, to establish the correct diagnosis, and to enable appropriate therapy.
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Affiliation(s)
- Frank Rutsch
- Department of General Pediatrics, Muenster University Children's Hospital, Germany
| | - Insa Buers
- Department of General Pediatrics, Muenster University Children's Hospital, Germany
| | - Yvonne Nitschke
- Department of General Pediatrics, Muenster University Children's Hospital, Germany
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25
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Katano H, Nishikawa Y, Yamada H, Iwata T, Mase M. Profile of genetic variations in severely calcified carotid plaques by whole-exome sequencing. Surg Neurol Int 2020; 11:286. [PMID: 33033648 PMCID: PMC7538800 DOI: 10.25259/sni_387_2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 08/19/2020] [Indexed: 01/26/2023] Open
Abstract
Background: The precise mechanisms of carotid calcification and its clinical significance have not been established. Methods: We classified ten plaques from carotid endarterectomy patients into high- and low-calcified plaques based on the Agatston calcium scores. We performed whole-exome sequencing for genetic profiles with single nucleotide variations (SNVs), insertions, and deletions. Bioinformatic data mining was then conducted to disclose specific gene variations to either high- or low-calcified carotid plaques. Results: In the carotid plaques, G:C>A:T/C:G>T:A transitions as SNVs, insT after C/insC after A as insertions, and delA after G/delT after C as deletions were most frequently observed, but no significant difference was observed between the high- and low-calcified plaque groups in their proportion of base-pair substitution types. In the bioinformatic analysis, SNVs of ATP binding cassette subfamily C member 6 (ADCC6) were more commonly found in high-calcified plaques and SNVs of KLKB1 were more commonly found in low-calcified plaques compared to the other group. No new genetic variants related to calcification or atherosclerosis among those not registered in dbSNP was detected. Conclusion: Our findings clarified the features of base-pair substitutions in carotid plaques, showing no relation to calcification. However, genetic variants in ADCC6 relating to vascular calcification for high-calcified plaques, and in KLKB1 encoding kallikrein associated with vascular regulation of atherosclerosis for low-calcified plaques were more specifically extracted. These results contribute to a better understanding of the genetic basis of molecular activity and calcium formation in carotid plaques.
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Affiliation(s)
- Hiroyuki Katano
- Department of Neurosurgery and Medical Informatics, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, Japan
| | - Yusuke Nishikawa
- Department of Neurosurgery, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, Japan
| | - Hiroshi Yamada
- Department of Neurosurgery, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, Japan
| | - Takashi Iwata
- Department of Neurosurgery, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, Japan
| | - Mitsuhito Mase
- Department of Neurosurgery, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, Japan
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26
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Zaker B, Ardalan M. Vascular calcification; Stony bridge between kidney and heart. J Cardiovasc Thorac Res 2020; 12:165-171. [PMID: 33123321 PMCID: PMC7581848 DOI: 10.34172/jcvtr.2020.29] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Accepted: 07/10/2020] [Indexed: 12/11/2022] Open
Abstract
Vascular calcification is a high prevalent complication that arises as a consequence of impaired calcium and phosphate balance amongst cardiovascular patients. Multiple inducer/ inhibitory molecules and pathways as well as genetic background and lifestyle play role in this phenomenon. According to which vessel layer (intima, media or both) is involved different types of vascular calcification take place. Actual mechanism and consensus pathways have not been elucidated yet and needs further investigations.
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Affiliation(s)
- Behzad Zaker
- Kidney Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.,Department of Biological Sciences, School of Natural Sciences, University of Tabriz, Tabriz, Iran
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27
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Boyce AM, Gafni RI, Ferreira CR. Generalized Arterial Calcification of Infancy: New Insights, Controversies, and Approach to Management. Curr Osteoporos Rep 2020; 18:232-241. [PMID: 32172442 PMCID: PMC9506683 DOI: 10.1007/s11914-020-00577-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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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28
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Oheim R, Zimmerman K, Maulding ND, Stürznickel J, von Kroge S, Kavanagh D, Stabach PR, Kornak U, Tommasini SM, Horowitz MC, Amling M, Thompson D, Schinke T, Busse B, Carpenter TO, Braddock DT. Human Heterozygous ENPP1 Deficiency Is Associated With Early Onset Osteoporosis, a Phenotype Recapitulated in a Mouse Model of Enpp1 Deficiency. J Bone Miner Res 2020; 35:528-539. [PMID: 31805212 PMCID: PMC7184798 DOI: 10.1002/jbmr.3911] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2019] [Revised: 09/27/2019] [Accepted: 10/14/2019] [Indexed: 12/15/2022]
Abstract
Biallelic ENPP1 deficiency in humans induces generalized arterial calcification of infancy (GACI) and/or autosomal recessive hypophosphatemic rickets type 2 (ARHR2). The latter is characterized by markedly increased circulating FGF23 levels and renal phosphate wasting, but aberrant skeletal manifestations associated with heterozygous ENPP1 deficiency are unknown. Here, we report three adult men with early onset osteoporosis who presented with fractures in the thoracic spine and/or left radius, mildly elevated circulating FGF23, and hypophosphatemia. Total hip bone mineral density scans demonstrated osteoporosis (Z-score < -2.5) and HRpQCT demonstrated microarchitectural defects in trabecular and cortical bone. Next-generation sequencing revealed heterozygous loss-of-function mutations in ENPP1 previously observed as biallelic mutations in infants with GACI. In addition, we present bone mass and structure data as well as plasma pyrophosphate (PPi) data of two siblings suffering from ARHR2 in comparison to their heterozygous and wild-type family members indicative of an ENPP1 gene dose effect. The skeletal phenotype in murine Enpp1 deficiency yielded nearly identical findings. Ten-week-old male Enpp1 asj/asj mice exhibited mild elevations in plasma FGF23 and hypophosphatemia, and micro-CT analysis revealed microarchitectural defects in trabecular and cortical bone of similar magnitude to HRpQCT defects observed in humans. Histomorphometry revealed mild osteomalacia and osteopenia at both 10 and 23 weeks. The biomechanical relevance of these findings was demonstrated by increased bone fragility and ductility in Enpp1 asj/asj mice. In summary, ENPP1 exerts a gene dose effect such that humans with heterozygous ENPP1 deficiency exhibit intermediate levels of plasma analytes associated with bone mineralization disturbance resulting in early onset osteoporosis. © 2019 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research.
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Affiliation(s)
- Ralf Oheim
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Kristin Zimmerman
- Department of Pathology, Yale University School of Medicine, New Haven, CT, USA
| | - Nathan D Maulding
- Department of Pathology, Yale University School of Medicine, New Haven, CT, USA
| | - Julian Stürznickel
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Simon von Kroge
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Dillon Kavanagh
- Department of Pathology, Yale University School of Medicine, New Haven, CT, USA
| | - Paul R Stabach
- Department of Pathology, Yale University School of Medicine, New Haven, CT, USA
| | - Uwe Kornak
- Institute of Medical Genetics and Human Genetics, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Steven M Tommasini
- Department of Orthoaedics and Rehabilitation, Yale University School of Medicine, New Haven, CT, USA
| | - Mark C Horowitz
- Department of Orthoaedics and Rehabilitation, Yale University School of Medicine, New Haven, CT, USA
| | - Michael Amling
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | - Thorsten Schinke
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Björn Busse
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Thomas O Carpenter
- Department of Orthoaedics and Rehabilitation, Yale University School of Medicine, New Haven, CT, USA.,Department of Pediatrics, Yale University School of Medicine, New Haven, CT, USA
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29
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Kranenburg G, de Jong PA, Bartstra JW, Lagerweij SJ, Lam MG, Ossewaarde-van Norel J, Risseeuw S, van Leeuwen R, Imhof SM, Verhaar HJ, de Vries JJ, Slart RHJA, Luurtsema G, den Harder AM, Visseren FLJ, Mali WP, Spiering W. Etidronate for Prevention of Ectopic Mineralization in Patients With Pseudoxanthoma Elasticum. J Am Coll Cardiol 2019. [PMID: 29519353 DOI: 10.1016/j.jacc.2017.12.062] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND In pseudoxanthoma elasticum (PXE), low pyrophosphate levels may cause ectopic mineralization, leading to skin changes, visual impairment, and peripheral arterial disease. OBJECTIVES The authors hypothesized that etidronate, a pyrophosphate analog, might reduce ectopic mineralization in PXE. METHODS In the Treatment of Ectopic Mineralization in Pseudoxanthoma Elasticum trial, adults with PXE and leg arterial calcifications (n = 74) were randomly assigned to etidronate or placebo (cyclical 20 mg/kg for 2 weeks every 12 weeks). The primary outcome was ectopic mineralization, quantified with 18fluoride positron emission tomography scans as femoral arterial wall target-to-background ratios (TBRfemoral). Secondary outcomes were computed tomography arterial calcification and ophthalmological changes. Safety outcomes were bone density, serum calcium, and phosphate. RESULTS During 12 months of follow-up, the TBRfemoral increased 6% (interquartile range [IQR]: -12% to 25%) in the etidronate group and 7% (IQR: -9% to 32%) in the placebo group (p = 0.465). Arterial calcification decreased 4% (IQR: -11% to 7%) in the etidronate group and increased 8% (IQR: -1% to 20%) in the placebo group (p = 0.001). Etidronate treatment was associated with significantly fewer subretinal neovascularization events (1 vs. 9, p = 0.007). Bone density decreased 4% ± 12% in the etidronate group and 6% ± 9% in the placebo group (p = 0.374). Hypocalcemia (<2.20 mmol/l) occurred in 3 versus 1 patient (8.1% vs. 2.7%, p = 0.304). Eighteen patients (48.6%) treated with etidronate, compared with 0 patients treated with placebo (p < 0.001), experienced hyperphosphatemia (>1.5 mmol/l) and recovered spontaneously. CONCLUSIONS In patients with PXE, etidronate reduced arterial calcification and subretinal neovascularization events but did not lower femoral 18fluoride sodium positron emission tomography activity compared with placebo, without important safety issues. (Treatment of Ectopic Mineralization in Pseudoxanthoma elasticum; NTR5180).
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Affiliation(s)
- Guido Kranenburg
- Department of Vascular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Pim A de Jong
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Jonas W Bartstra
- Department of Vascular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Suzanne J Lagerweij
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Marnix G Lam
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | | | - Sara Risseeuw
- Department of Ophthalmology, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Redmer van Leeuwen
- Department of Ophthalmology, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Saskia M Imhof
- Department of Ophthalmology, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Harald J Verhaar
- Department of Geriatric Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Job J de Vries
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Riemer H J A Slart
- Medical Imaging Center, Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Gert Luurtsema
- Medical Imaging Center, Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Annemarie M den Harder
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Frank L J Visseren
- Department of Vascular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Willem P Mali
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Wilko Spiering
- Department of Vascular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands.
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Quantitative Trait Locus and Integrative Genomics Revealed Candidate Modifier Genes for Ectopic Mineralization in Mouse Models of Pseudoxanthoma Elasticum. J Invest Dermatol 2019; 139:2447-2457.e7. [PMID: 31207231 DOI: 10.1016/j.jid.2019.04.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 03/28/2019] [Accepted: 04/26/2019] [Indexed: 02/06/2023]
Abstract
Pseudoxanthoma elasticum, a prototype of heritable multisystem ectopic mineralization disorders, is caused by mutations in the ABCC6 gene encoding a putative efflux transporter, ABCC6. The phenotypic spectrum of pseudoxanthoma elasticum varies, and the correlation between genotype and phenotype has not been established. To identify genetic modifiers, we performed quantitative trait locus analysis in inbred mouse strains that carry the same hypomorphic allele in Abcc6 yet with highly variable ectopic mineralization phenotypes of pseudoxanthoma elasticum. Abcc6 was confirmed as a major determinant for ectopic mineralization in multiple tissues. Integrative analysis using functional genomics tools that included GeneWeaver, String, and Mouse Genome Informatics identified a total of nine additional candidate modifier genes that could influence the organ-specific ectopic mineralization phenotypes. Integration of the candidate genes into the existing ectopic mineralization gene network expands the current knowledge on the complexity of the network that, as a whole, governs ectopic mineralization in soft connective tissues.
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Huang J, Snook AE, Uitto J, Li Q. Adenovirus-Mediated ABCC6 Gene Therapy for Heritable Ectopic Mineralization Disorders. J Invest Dermatol 2019; 139:1254-1263. [PMID: 30639429 DOI: 10.1016/j.jid.2018.12.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 12/13/2018] [Accepted: 12/20/2018] [Indexed: 01/27/2023]
Abstract
Loss-of-function mutations in the ABCC6 gene cause pseudoxanthoma elasticum and type 2 generalized arterial calcification of infancy, heritable ectopic mineralization disorders without effective treatment. ABCC6 encodes the putative efflux transporter ABCC6, which is predominantly expressed in the liver. Although the substrate of ABCC6 remains unknown, recent studies showed that pseudoxanthoma elasticum is a metabolic disorder caused by reduced circulating levels of pyrophosphate, a potent mineralization inhibitor. We hypothesized that reconstitution of ABCC6 might counteract ectopic mineralization in an Abcc6-/- mouse model of pseudoxanthoma elasticum. Intravenous administration of a recombinant adenovirus expressing wild-type human ABCC6 in Abcc6-/- mice showed sustained high-level expression of human ABCC6 in the liver for up to 4 weeks, increasing pyrophosphate levels in plasma. In addition, adenovirus injection every 4 weeks restored plasma pyrophosphate levels and, consequently, significantly reduced ectopic mineralization in the skin of young mice. By contrast, the same treatment in old mice with already established mineral deposits failed to reduce mineralization. These results suggest that adenovirus-mediated ABCC6 gene delivery, when initiated early, is a promising prevention therapy for pseudoxanthoma elasticum and generalized arterial calcification of infancy, diseases that currently lack preventive or therapeutic options.
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Affiliation(s)
- Jianhe Huang
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, and PXE International Center of Excellence in Research and Clinical Care, Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Adam E Snook
- Department of Pharmacology and Experimental Therapeutics, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Jouni Uitto
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, and PXE International Center of Excellence in Research and Clinical Care, Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Qiaoli Li
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, and PXE International Center of Excellence in Research and Clinical Care, Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania, USA.
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Li Q, van de Wetering K, Uitto J. Pseudoxanthoma Elasticum as a Paradigm of Heritable Ectopic Mineralization Disorders: Pathomechanisms and Treatment Development. THE AMERICAN JOURNAL OF PATHOLOGY 2018; 189:216-225. [PMID: 30414410 DOI: 10.1016/j.ajpath.2018.09.014] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 08/17/2018] [Accepted: 09/26/2018] [Indexed: 12/24/2022]
Abstract
Ectopic mineralization is a global problem and leading cause of morbidity and mortality. The pathomechanisms of ectopic mineralization are poorly understood. Recent studies on heritable ectopic mineralization disorders with defined gene defects have been helpful in elucidation of the mechanisms of ectopic mineralization in general. The prototype of such disorders is pseudoxanthoma elasticum (PXE), a late-onset, slowly progressing disorder with multisystem clinical manifestations. Other conditions include generalized arterial calcification of infancy (GACI), characterized by severe, early-onset mineralization of the cardiovascular system, often with early postnatal demise. In addition, arterial calcification due to CD73 deficiency (ACDC) occurs late in life, mostly affecting arteries in the lower extremities in elderly individuals. These three conditions, PXE, GACI, and ACDC, caused by mutations in ABCC6, ENPP1, and NT5E, respectively, are characterized by reduced levels of inorganic pyrophosphate (PPi) in plasma. Because PPi is a powerful antimineralization factor, it has been postulated that reduced PPi is a major determinant for ectopic mineralization in these conditions. These and related observations on complementary mechanisms of ectopic mineralization have resulted in development of potential treatment modalities for PXE, including administration of bisphosphonates, stable PPi analogs with antimineralization activity. It is conceivable that efficient treatments may soon become available for heritable ectopic mineralization disorders with application to common calcification disorders.
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Affiliation(s)
- Qiaoli Li
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, the PXE International Center of Excellence in Research and Clinical Care, and the Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania.
| | - Koen van de Wetering
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, the PXE International Center of Excellence in Research and Clinical Care, and the Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Jouni Uitto
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, the PXE International Center of Excellence in Research and Clinical Care, and the Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania
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Liu YF, Han TY, Tong XM, Wang J, Tang YN, Cui LG, Zhu XH, Piao MH, Wang QQ, Wu H. [Persistent hypertension for two months in a preterm infant]. ZHONGGUO DANG DAI ER KE ZA ZHI = CHINESE JOURNAL OF CONTEMPORARY PEDIATRICS 2018; 20:939-943. [PMID: 30477627 PMCID: PMC7389023 DOI: 10.7499/j.issn.1008-8830.2018.11.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 10/23/2018] [Indexed: 06/09/2023]
Abstract
A boy aged 2 months (born at 36 weeks of gestation) was admitted due to cough and dyspnea. After admission, he was found to have persistent hypertension, proteinuria, and persistent convulsion, and imaging examination showed extensive calcification of the aorta and major branches and stenosis of local lumens of the abdominal aorta and the right renal artery with increased blood flow velocity. The boy was admitted during the neonatal period due to wet lung and pulmonary arterial hypertension and was found to have hypertension and proteinuria. High-throughput whole-exome sequencing was performed and found two compound heterozygous mutations in the ENPP1 gene from his parents, c.130C>T (p.Q44X) and c.1112A>T (p.Y371F). c.130C>T was a nonsense mutation, which could cause partial deletion of protein from 44 amino acids, and was defined as a primary pathogenic mutation. c.1112A>T was a missense mutation which had been reported as a pathogenic mutation associated with idiopathic infantile arterial calcification (IIAC). Therefore, he was diagnosed with IIAC. He was given phosphonate drugs, antihypertensive drugs, anticonvulsion treatment, and respiratory support. Blood pressure was maintained at the upper limit of normal value. There was no deterioration of arterial calcification. It is concluded that IIAC should be considered for infants with persistent hypertension and extensive vascular calcification, and imaging and genetic examinations should be performed as early as possible to make a confirmed diagnosis.
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Affiliation(s)
- Yun-Feng Liu
- Department of Pediatrics, Peking University Third Hospital, Beijing 100191, China.
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Liu YF, Han TY, Tong XM, Wang J, Tang YN, Cui LG, Zhu XH, Piao MH, Wang QQ, Wu H. [Persistent hypertension for two months in a preterm infant]. ZHONGGUO DANG DAI ER KE ZA ZHI = CHINESE JOURNAL OF CONTEMPORARY PEDIATRICS 2018; 20:939-943. [PMID: 30477627 PMCID: PMC7389023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 10/23/2018] [Indexed: 11/12/2023]
Abstract
A boy aged 2 months (born at 36 weeks of gestation) was admitted due to cough and dyspnea. After admission, he was found to have persistent hypertension, proteinuria, and persistent convulsion, and imaging examination showed extensive calcification of the aorta and major branches and stenosis of local lumens of the abdominal aorta and the right renal artery with increased blood flow velocity. The boy was admitted during the neonatal period due to wet lung and pulmonary arterial hypertension and was found to have hypertension and proteinuria. High-throughput whole-exome sequencing was performed and found two compound heterozygous mutations in the ENPP1 gene from his parents, c.130C>T (p.Q44X) and c.1112A>T (p.Y371F). c.130C>T was a nonsense mutation, which could cause partial deletion of protein from 44 amino acids, and was defined as a primary pathogenic mutation. c.1112A>T was a missense mutation which had been reported as a pathogenic mutation associated with idiopathic infantile arterial calcification (IIAC). Therefore, he was diagnosed with IIAC. He was given phosphonate drugs, antihypertensive drugs, anticonvulsion treatment, and respiratory support. Blood pressure was maintained at the upper limit of normal value. There was no deterioration of arterial calcification. It is concluded that IIAC should be considered for infants with persistent hypertension and extensive vascular calcification, and imaging and genetic examinations should be performed as early as possible to make a confirmed diagnosis.
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Affiliation(s)
- Yun-Feng Liu
- Department of Pediatrics, Peking University Third Hospital, Beijing 100191, China.
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Akhtar Ali S, Ng C, Votava-Smith JK, Randolph LM, Pitukcheewanont P. Bisphosphonate therapy in an infant with generalized arterial calcification with an ABCC6 mutation. Osteoporos Int 2018; 29:2575-2579. [PMID: 30206659 DOI: 10.1007/s00198-018-4639-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 07/10/2018] [Indexed: 01/31/2023]
Abstract
Generalized arterial calcification of infancy (GACI) is a rare genetic disorder with high infantile mortality, described to be due to ENPP1, and less commonly ABCC6 mutations. Bisphosphonate treatment has been described to improve survival in ENPP1-positive GACI patients, but few studies have described bisphosphonate treatment in ABCC6-positive patients. Without therapy, patients will die before 6 months of age. Our patient is now 3 years old, former recipient twin of twin-to-twin transfusion syndrome (TTTS). Initial fetal echocardiogram at 19 weeks showed calcifications of the ascending aorta and pulmonary artery (PA). She underwent utero laser therapy, and despite resolution of the TTTS, her follow-up scans showed progressive calcification of the aorta and PA. Postnatal echocardiogram showed calcification and supravalvar stenosis of the aorta and PA. CT on day of life 6 showed calcifications in the PAs, aortic arch, and descending aorta. Quantification of valvular calcification can be difficult; in our patient, increasing outflow tract gradient on echocardiogram was used to monitor disease progression. Molecular testing revealed an ABCC6 gene mutation. She was started on weekly IV pamidronate (0.1-0.3 mg/kg/week) on day 8 of life then transitioned to oral etidronate (15-20 mg/kg/day). Given progressive supravalvar aortic and pulmonary stenosis, she underwent surgical repair with patch augmentation of the PA and ascending aorta at 4 months old. She has done well post-operatively, continuing on enteral bisphosphonate therapy with no side effects to date. Her identical twin was confirmed to have the same mutation and remains asymptomatic with no calcifications. Aggressive bisphosphonate therapy should be started as soon as possible in patients with infantile arterial calcinosis due to ABCC6 or ENPP1 mutations. Echocardiographic evaluation can be used to monitor disease progression by arterial gradients. Molecular testing is also essential to evaluate for possible co-morbidities in these patients and pregnancy management for the future.
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Affiliation(s)
- S Akhtar Ali
- Center For Endocrinology, Diabetes and Metabolism, Children's Hospital Los Angeles and Keck School of Medicine of University of Southern California, Los Angeles, CA, USA
| | - C Ng
- Division of Pediatric Endocrinology, Huntington Health Physicians, Huntington, CA, USA
| | - J K Votava-Smith
- Division of Pediatric Cardiology, Children's Hospital Los Angeles and Keck School of Medicine of University of Southern California, Los Angeles, CA, USA
| | - L M Randolph
- Division of Medical Genetics, Children's Hospital Los Angeles and Keck School of Medicine of University of Southern California, Los Angeles, CA, USA
| | - P Pitukcheewanont
- Center For Endocrinology, Diabetes and Metabolism, Children's Hospital Los Angeles and Keck School of Medicine of University of Southern California, Los Angeles, CA, USA.
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Li Q, Huang J, Pinkerton AB, Millan JL, van Zelst BD, Levine MA, Sundberg JP, Uitto J. Inhibition of Tissue-Nonspecific Alkaline Phosphatase Attenuates Ectopic Mineralization in the Abcc6 -/- Mouse Model of PXE but Not in the Enpp1 Mutant Mouse Models of GACI. J Invest Dermatol 2018; 139:360-368. [PMID: 30130617 DOI: 10.1016/j.jid.2018.07.030] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 07/18/2018] [Accepted: 07/19/2018] [Indexed: 10/28/2022]
Abstract
Pseudoxanthoma elasticum (PXE), a prototype of heritable ectopic mineralization disorders, is caused by mutations in the ABCC6 gene encoding a putative efflux transporter ABCC6. It was recently shown that the absence of ABCC6-mediated adenosine triphosphate release from the liver and, consequently, reduced inorganic pyrophosphate levels underlie the pathogenesis of PXE. Given that tissue-nonspecific alkaline phosphatase (TNAP), encoded by ALPL, is the enzyme responsible for degrading inorganic pyrophosphate, we hypothesized that reducing TNAP levels either by genetic or pharmacological means would lead to amelioration of the ectopic mineralization phenotype in the Abcc6-/- mouse model of PXE. Thus, we bred Abcc6-/- mice to heterozygous Alpl+/- mice that display approximately 50% plasma TNAP activity. The Abcc6-/-Alpl+/- double-mutant mice showed 52% reduction of mineralization in the muzzle skin compared with the Abcc6-/-Alpl+/+ mice. Subsequently, oral administration of SBI-425, a small molecule inhibitor of TNAP, resulted in 61% reduction of plasma TNAP activity and 58% reduction of mineralization in the muzzle skin of Abcc6-/- mice. By contrast, SBI-425 treatment of Enpp1 mutant mice, another model of ectopic mineralization associated with reduced inorganic pyrophosphate, failed to reduce muzzle skin mineralization. These results suggest that inhibition of TNAP might provide a promising treatment strategy for PXE, a currently intractable disease.
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Affiliation(s)
- Qiaoli Li
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College and PXE International Center of Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, Pennsylvania, USA.
| | - Jianhe Huang
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College and PXE International Center of Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Anthony B Pinkerton
- Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, California, USA
| | - Jose Luis Millan
- Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, California, USA
| | - Bertrand D van Zelst
- Department of Clinical Chemistry, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Michael A Levine
- Division of Endocrinology, Children's Hospital of Philadelphia, and University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | | | - Jouni Uitto
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College and PXE International Center of Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
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Li Q, Kingman J, Sundberg JP, Levine MA, Uitto J. Etidronate prevents, but does not reverse, ectopic mineralization in a mouse model of pseudoxanthoma elasticum ( Abcc6-/- ). Oncotarget 2018; 9:30721-30730. [PMID: 30112102 PMCID: PMC6089405 DOI: 10.18632/oncotarget.10738] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 06/09/2016] [Indexed: 12/13/2022] Open
Abstract
Pseudoxanthoma elasticum (PXE) and generalized arterial calcification of infancy (GACI) are heritable disorders manifesting with ectopic tissue mineralization. Most cases of PXE and some cases of GACI are caused by mutations in the ABCC6 gene, resulting in reduced plasma pyrophosphate (PPi) levels. There is no effective treatment for these disorders. It has been suggested that administration of bisphosphonates, stable and non-hydrolyzable PPi analogs, could counteract ectopic mineralization in these disorders. In this study we tested the potential efficacy of etidronate, a first generation bisphosphonate, on ectopic mineralization in the muzzle skin of Abcc6-/- mice, a model of PXE. The Abcc6-/- mice received subcutaneous injections of etidronate, 0.283 and 3.40 mg/kg per injection (0.01× and 0.12×), twice a week, in both prevention and reversal studies. Ectopic mineralization in the dermal sheath of vibrissae in muzzle skin was determined by histopathologic analysis and by direct chemical assay for calcium content. Subcutaneous injection of etidronate prevented ectopic mineralization but did not reverse existing mineralization. The effect of etidronate was accompanied by alterations in the trabecular bone microarchitecture, determined by micro-computed tomography. The results suggest that etidronate may offer a potential treatment modality for PXE and GACI caused by ABCC6 mutations. Etidronate therapy should be initiated in PXE patients as soon as the diagnosis is made, with careful monitoring of potential side effects.
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Affiliation(s)
- Qiaoli Li
- Department of Dermatology and Cutaneous Biology, The Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA, USA
| | - Joshua Kingman
- Department of Dermatology and Cutaneous Biology, The Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA, USA
| | | | - Michael A. Levine
- Division of Endocrinology and Diabetes, Children's Hospital of Philadelphia and University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Jouni Uitto
- Department of Dermatology and Cutaneous Biology, The Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA, USA
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Bertamino M, Severino M, Grossi A, Rusmini M, Tortora D, Gandolfo C, Pederzoli S, Malattia C, Picco P, Striano P, Ceccherini I, Di Rocco M, Banov L, Capra V, Giacomini T, Lanteri P, Minoia F, Molinari AC, Moretti P, Moscatelli A, Vari MS, Palmieri A, Pavanello M, Prato G, Ramenghi LA, Rimini A, Rossi A, Uccella S. ABCC6 mutations and early onset stroke: Two cases of a typical Pseudoxanthoma Elasticum. Eur J Paediatr Neurol 2018; 22:725-728. [PMID: 29709427 DOI: 10.1016/j.ejpn.2018.04.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 02/14/2018] [Accepted: 04/04/2018] [Indexed: 10/17/2022]
Abstract
Pseudoxanthoma elasticum (PXE) is a rare genetic disorder characterized by fragmented and mineralized elastic fibers in the mid-dermis of the skin, eye, digestive tract and cardiovascular system. Clinical presentation includes typical skin lesions, ocular angioid streaks, and multisystem vasculopathy. The age of onset varies considerably from infancy to old age, but the diagnosis is usually made in young adults due to frequent absence of pathognomonic skin and ocular manifestations in early childhood. We report two children with PXE presenting with isolated multisystem vasculopathy and early-onset stroke. In the first patient, diagnosis was delayed until typical dermatologic alterations appeared; in the second patient, next-generation sequencing (NGS) study led to early diagnosis and specific follow-up, underlying the crucial role in idiopathic pediatric stroke of early genetic testing using NGS-based panels.
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Affiliation(s)
- Marta Bertamino
- Thrombosis and Hemostasis Unit, Istituto Giannina Gaslini, Genoa, Italy.
| | | | - Alice Grossi
- Medical Genetics Unit, Istituto Giannina Gaslini, Genoa, Italy
| | - Marta Rusmini
- Medical Genetics Unit, Istituto Giannina Gaslini, Genoa, Italy
| | | | - Carlo Gandolfo
- Neuroradiology Unit, Istituto Giannina Gaslini, Genoa, Italy
| | | | - Clara Malattia
- Rheumatology Unit, Istituto Giannina Gaslini, Genoa, Italy
| | - Paolo Picco
- Rheumatology Unit, Istituto Giannina Gaslini, Genoa, Italy
| | - Pasquale Striano
- Pediatric Neurology and Muscular Diseases Unit, Istituto Giannina Gaslini, Genova, Italy
| | | | - Maja Di Rocco
- Rare Disease Unit, Istituto Giannina Gaslini, Genoa, Italy
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Parreira B, Cardoso JCR, Costa R, Couto AR, Bruges-Armas J, Power DM. Persistence of the ABCC6 genes and the emergence of the bony skeleton in vertebrates. Sci Rep 2018; 8:6027. [PMID: 29662086 PMCID: PMC5902450 DOI: 10.1038/s41598-018-24370-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 03/22/2018] [Indexed: 12/18/2022] Open
Abstract
The ATP-binding cassette transporter 6 (ABCC6) gene encodes a cellular transmembrane protein transporter (MRP6) that is involved in the regulation of tissue calcification in mammals. Mutations in ABCC6 are associated with human ectopic calcification disorders. To gain insight into its evolution and involvement in tissue calcification we conducted a comparative analysis of the ABCC6 gene and the related gene ABCC1 from invertebrates to vertebrates where a bony endoskeleton first evolved. Taking into consideration the role of ABCC6 in ectopic calcification of human skin we analysed the involvement of both genes in the regeneration of scales, mineralized structures that develop in fish skin. The ABCC6 gene was only found in bony vertebrate genomes and was absent from Elasmobranchs, Agnatha and from invertebrates. In teleost fish the abcc6 gene duplicated but the two genes persisted only in some teleost genomes. Six disease causing amino acid mutations in human MRP6 are a normal feature of abcc6 in fish, suggesting they do not have a deleterious effect on the protein. After scale removal the abcc6 (5 and 10 days) and abcc1 (10 days) gene expression was up-regulated relative to the intact control skin and this coincided with a time of intense scale mineralization.
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Affiliation(s)
- Bruna Parreira
- Serviço Especializado de Epidemiologia e Biologia Molecular (SEEBMO), Hospital de Santo Espírito da Ilha Terceira, Azores, Portugal
| | - João C R Cardoso
- Centre of Marine Sciences (CCMAR), Universidade do Algarve, Campus de Gambelas, 8005-139, Faro, Portugal
| | - Rita Costa
- Centre of Marine Sciences (CCMAR), Universidade do Algarve, Campus de Gambelas, 8005-139, Faro, Portugal
| | - Ana Rita Couto
- Serviço Especializado de Epidemiologia e Biologia Molecular (SEEBMO), Hospital de Santo Espírito da Ilha Terceira, Azores, Portugal
| | - Jácome Bruges-Armas
- Serviço Especializado de Epidemiologia e Biologia Molecular (SEEBMO), Hospital de Santo Espírito da Ilha Terceira, Azores, Portugal.,CEDOC - Chronic Diseases Research Center, Universidade Nova de Lisboa, Lisbon, Portugal
| | - Deborah M Power
- Centre of Marine Sciences (CCMAR), Universidade do Algarve, Campus de Gambelas, 8005-139, Faro, Portugal. .,Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, China.
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40
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Zhao J, Kingman J, Sundberg JP, Uitto J, Li Q. Plasma PPi Deficiency Is the Major, but Not the Exclusive, Cause of Ectopic Mineralization in an Abcc6 -/- Mouse Model of PXE. J Invest Dermatol 2017; 137:2336-2343. [PMID: 28652107 DOI: 10.1016/j.jid.2017.06.006] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 05/31/2017] [Accepted: 06/02/2017] [Indexed: 12/13/2022]
Abstract
Pseudoxanthoma elasticum (PXE), a prototype of heritable ectopic mineralization disorders, is caused in most cases by inactivating mutations in the ABCC6 gene. It was recently discovered that absence of ABCC6-mediated adenosine triphosphate release from the liver and consequently reduced plasma inorganic pyrophosphate (PPi) levels underlie PXE. This study examined whether reduced levels of circulating PPi, an antimineralization factor, is the sole mechanism of PXE. The Abcc6-/- and Enpp1asj mice were crossed with transgenic mice expressing human ENPP1, an ectonucleotidase that generates PPi from adenosine triphosphate. We generated Abcc6-/- and Enpp1asj mice, either wild-type or hemizygous for human ENPP1. Plasma levels of PPi and the degree of ectopic mineralization were determined. Overexpression of human ENPP1 in Enpp1asj mice normalized plasma PPi levels to that of wild-type mice and, consequently, completely prevented ectopic mineralization. These changes were accompanied by restoration of their bone microarchitecture. In contrast, although significantly reduced mineralization was noted in Abcc6-/- mice expressing human ENPP1, small mineralization foci were still evident despite increased plasma PPi levels. These results suggest that PPi is the major mediator of ectopic mineralization in PXE, but there might be an alternative, as yet unknown mechanism, independent of PPi, by which ABCC6 prevents ectopic mineralization under physiologic conditions.
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Affiliation(s)
- Jingyi Zhao
- Department of Dermatology and Cutaneous Biology, The Sidney Kimmel Medical College, and the PXE International Center of Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, Pennsylvania, USA; Department of Dermatology, The First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, China
| | - Joshua Kingman
- Department of Dermatology and Cutaneous Biology, The Sidney Kimmel Medical College, and the PXE International Center of Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | | | - Jouni Uitto
- Department of Dermatology and Cutaneous Biology, The Sidney Kimmel Medical College, and the PXE International Center of Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, Pennsylvania, USA; Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Qiaoli Li
- Department of Dermatology and Cutaneous Biology, The Sidney Kimmel Medical College, and the PXE International Center of Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, Pennsylvania, USA; Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania, USA.
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Uitto J, Li Q, van de Wetering K, Váradi A, Terry SF. Insights into Pathomechanisms and Treatment Development in Heritable Ectopic Mineralization Disorders: Summary of the PXE International Biennial Research Symposium-2016. J Invest Dermatol 2017; 137:790-795. [PMID: 28340679 PMCID: PMC5831331 DOI: 10.1016/j.jid.2016.12.014] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 12/07/2016] [Accepted: 12/11/2016] [Indexed: 02/06/2023]
Abstract
Pseudoxanthoma elasticum is a prototype of heritable ectopic mineralization disorders, with phenotypic overlap with generalized arterial calcification of infancy and arterial calcification due to CD73 deficiency. Recent observations have suggested that the reduced inorganic pyrophosphate/phosphate ratio is the cause of soft connective tissue mineralization in these disorders. PXE International, a patient advocacy organization, supports research in part by sponsoring biennial research symposia on these disorders; the latest meeting was held in September 2016 at Thomas Jefferson University, Philadelphia. This report summarizes the progress in pseudoxanthoma elasticum and other ectopic mineralization disorders, as presented in the symposium, with focus on translational aspects of precision medicine toward improved diagnostics and treatment development for these currently intractable disorders.
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Affiliation(s)
- Jouni Uitto
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, and PXE International Center of Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, Pennsylvania, USA.
| | - Qiaoli Li
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, and PXE International Center of Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Koen van de Wetering
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, and PXE International Center of Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - András Váradi
- Institute of Enzymology, RCNS, Hungarian Academy of Sciences, Budapest, Hungary
| | - Sharon F Terry
- PXE International, Washington, District of Columbia, USA
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Iwanaga A, Okubo Y, Yozaki M, Koike Y, Kuwatsuka Y, Tomimura S, Yamamoto Y, Tamura H, Ikeda S, Maemura K, Tsuiki E, Kitaoka T, Endo Y, Mishima H, Yoshiura KI, Ogi T, Tanizaki H, Wataya-Kaneda M, Hattori T, Utani A. Analysis of clinical symptoms andABCC6mutations in 76 Japanese patients with pseudoxanthoma elasticum. J Dermatol 2017; 44:644-650. [DOI: 10.1111/1346-8138.13727] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 11/10/2016] [Indexed: 10/20/2022]
Affiliation(s)
- Akira Iwanaga
- Department of Dermatology; Graduate School of Biomedical Sciences; Nagasaki University Nagasaki Japan
| | - Yumi Okubo
- Department of Dermatology; Graduate School of Biomedical Sciences; Nagasaki University Nagasaki Japan
| | - Mariko Yozaki
- Department of Dermatology; Graduate School of Biomedical Sciences; Nagasaki University Nagasaki Japan
| | - Yuta Koike
- Department of Dermatology; Graduate School of Biomedical Sciences; Nagasaki University Nagasaki Japan
| | - Yutaka Kuwatsuka
- Department of Dermatology; Graduate School of Biomedical Sciences; Nagasaki University Nagasaki Japan
| | - Saori Tomimura
- Department of Dermatology; Graduate School of Biomedical Sciences; Nagasaki University Nagasaki Japan
| | - Yosuke Yamamoto
- Department of Healthcare Epidemiology Research; Graduate School of Medicine; Kyoto University; Kyoto Japan
- Department of Dermatology; Graduate School of Biomedical Sciences; Kyoto University; Kyoto Japan
| | - Hiroshi Tamura
- Department of Ophthalmology and Visual Sciences; Graduate School of Medicine; Kyoto University; Kyoto Japan
- Division of Medical Information Technology and Administration Planning; Kyoto University Hospital; Kyoto Japan
| | - Satoshi Ikeda
- Department of Cardiovascular Medicine; Graduate School of Biomedical Sciences; Nagasaki University; Nagasaki Japan
| | - Koji Maemura
- Department of Cardiovascular Medicine; Graduate School of Biomedical Sciences; Nagasaki University; Nagasaki Japan
| | - Eiko Tsuiki
- Department of Ophthalmology; Graduate School of Biomedical Sciences; Nagasaki University; Nagasaki Japan
| | - Takashi Kitaoka
- Department of Ophthalmology; Graduate School of Biomedical Sciences; Nagasaki University; Nagasaki Japan
| | - Yuichiro Endo
- Department of Dermatology; Graduate School of Biomedical Sciences; Kyoto University; Kyoto Japan
| | - Hiroyuki Mishima
- Department of Human Genetics; Graduate School of Biomedical Sciences; Nagasaki University; Nagasaki Japan
| | - Koh-Ichiro Yoshiura
- Department of Human Genetics; Graduate School of Biomedical Sciences; Nagasaki University; Nagasaki Japan
| | - Tomoo Ogi
- Department of Genetics; Research Institute of Environmental Medicine; Nagoya University; Aichi Japan
| | | | - Mari Wataya-Kaneda
- Department of Dermatology; Graduate School of Medicine; Osaka University; Osaka Japan
| | - Tomoyasu Hattori
- Department of Dermatology; Graduate School of Medicine; Gunma University; Gunma Japan
| | - Atsushi Utani
- Department of Dermatology; Graduate School of Biomedical Sciences; Nagasaki University Nagasaki Japan
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Cerebral disease in a nationwide Dutch pseudoxanthoma elasticum cohort with a systematic review of the literature. J Neurol Sci 2017; 373:167-172. [DOI: 10.1016/j.jns.2016.12.053] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 11/29/2016] [Accepted: 12/26/2016] [Indexed: 01/09/2023]
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Idiopathic infantile arterial calcification: a case report of successful extracorporeal membrane oxygenation support. Int J Artif Organs 2017; 39:575-579. [PMID: 28085170 DOI: 10.5301/ijao.5000544] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/31/2016] [Indexed: 11/20/2022]
Abstract
Idiopathic infantile arterial calcification is a rare cause of infantile ischemic cardiac failure with extremely poor prognosis. We present the first case report of successful extracorporeal membrane oxygenation support and outcome in a child with idiopathic infantile arterial calcification (IIAC). This 6-week-old infant presented with cardiogenic shock and circulatory collapse. The patient underwent extracorporeal cardiopulmonary resuscitation, allowing stabilization, diagnosis, and treatment with etidronate, followed by successful discharge to home.
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Kranenburg G, de Jong PA, Mali WP, Attrach M, Visseren FL, Spiering W. Prevalence and severity of arterial calcifications in pseudoxanthoma elasticum (PXE) compared to hospital controls. Novel insights into the vascular phenotype of PXE. Atherosclerosis 2017; 256:7-14. [DOI: 10.1016/j.atherosclerosis.2016.11.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 10/27/2016] [Accepted: 11/10/2016] [Indexed: 01/23/2023]
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Li Q, Kingman J, Uitto J. Mineral content of the maternal diet influences ectopic mineralization in offspring of Abcc6(-/-) mice. Cell Cycle 2016. [PMID: 26199043 DOI: 10.1080/15384101.2015.1068473] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Ectopic mineralization disorders inflicting the connective tissues display a spectrum of severity, some developing in utero and being diagnosed by prenatal ultrasound. This study was designed to test the hypothesis that the mineral content of maternal diet can influence the mineralization in the offspring. Pregnant Abcc6(-/-) mice, on 2 different strain backgrounds, were maintained either on normal rodent diet or on "acceleration diet," rich in phosphate and low in magnesium, which has been previously shown to enhance the mineralization processes. The offspring were examined for mineralization by histopathology of various tissues and quantitated by chemical assay of calcium. The ectopic mineralization in the dermal sheath of vibrissae, a progressive biomarker of the overall mineralization, was readily detectable at the age of 4 weeks in the pups whose mothers were on the acceleration diet, while no evidence of mineralization was noted in those on normal diet. The mineralization of the vibrissae progressively increased when examined at 12 weeks of age. There was a significant reduction in urinary calcium and significant increase in urinary phosphorus concentrations both at 4 and 12 weeks of age in mice on the acceleration diet as compared to those on control diet. The results demonstrate that the mineral content of the maternal diet can influence ectopic mineralization in the offspring of mice genetically predisposed to ectopic mineralization (Abcc6(-/-)). These observations have implications for dietary management of pregnancies in which the fetus is diagnosed by prenatal ultrasound to have an ectopic mineralization disorder.
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Affiliation(s)
- Qiaoli Li
- a Department of Dermatology and Cutaneous Biology ; The Sidney Kimmel Medical College; Thomas Jefferson University ; Philadelphia , PA USA
| | - Joshua Kingman
- a Department of Dermatology and Cutaneous Biology ; The Sidney Kimmel Medical College; Thomas Jefferson University ; Philadelphia , PA USA
| | - Jouni Uitto
- a Department of Dermatology and Cutaneous Biology ; The Sidney Kimmel Medical College; Thomas Jefferson University ; Philadelphia , PA USA
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Li Q, Kingman J, Sundberg JP, Levine MA, Uitto J. Dual Effects of Bisphosphonates on Ectopic Skin and Vascular Soft Tissue Mineralization versus Bone Microarchitecture in a Mouse Model of Generalized Arterial Calcification of Infancy. J Invest Dermatol 2016; 136:275-283. [PMID: 26763447 PMCID: PMC4731049 DOI: 10.1038/jid.2015.377] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Revised: 09/02/2015] [Accepted: 09/11/2015] [Indexed: 12/30/2022]
Abstract
Generalized arterial calcification of infancy (GACI) is an intractable ectopic mineralization disorder caused by mutations in the ENPP1 gene resulting in reduced plasma inorganic pyrophosphate levels. We previously characterized the Enpp1asj mutant mouse as a model of GACI, and we have now explored the potential efficacy of bisphosphonates, non-hydrolyzable PPi analogs, in preventing ectopic mineralization in these mice. These mice were maintained on either basic diet (control) or diets containing etidronate or alendronate in three different concentrations (experimental). Considering low bioavailability of bisphosphonates when administered orally, subsequent studies tested the mice with subcutaneous injections of etidronate. The treatments were initiated at 4 weeks of age, and the degree of mineralization was assessed at 12 weeks of age by quantitation of calcium deposits in the muzzle skin containing dermal sheath of vibrissae and in aorta. We found that bisphosphonate treatments significantly reduced mineralization in skin and aorta. These changes in treated mice were accompanied with restoration of their bone microarchitecture, determined bymicrocomputed tomography. The inhibitory capacity of bisphosphonates, with mechanistic implications, was confirmed in a cell-based mineralization assay in vitro. Collectively, these results suggest that bisphosphonate treatment may be beneficial by a dual effect for preventing ectopic soft tissue mineralization while correcting decreased bone mineralization in GACI caused by ENPP1 mutations.
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Affiliation(s)
- Qiaoli Li
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania, USA.
| | - Joshua Kingman
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | | | - Michael A Levine
- Division of Endocrinology, Children's Hospital of Philadelphia, Philadelphia, USA
| | - Jouni Uitto
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania, USA
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48
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Li Q, Sundberg JP, Levine MA, Terry SF, Uitto J. The effects of bisphosphonates on ectopic soft tissue mineralization caused by mutations in the ABCC6 gene. Cell Cycle 2015; 14:1082-9. [PMID: 25607347 DOI: 10.1080/15384101.2015.1007809] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Pseudoxanthoma elasticum (PXE) and generalized arterial calcification of infancy (GACI) are heritable ectopic mineralization disorders. Most cases of PXE and many cases of GACI harbor mutations in the ABCC6 gene. There is no effective treatment for these disorders. We explored the potential efficacy of bisphosphonates to prevent ectopic calcification caused by ABCC6 mutations by feeding Abcc6(-/-) mice with diet containing etidronate disodium (ETD) or alendronate sodium trihydrate (AST) in quantities corresponding to 1x, 5x, or 12x of the doses used to treat osteoporosis in humans. The mice were placed on diet at 4 weeks of age, and the degree of mineralization was assessed at 12 weeks by quantitation of the calcium deposits in the dermal sheath of vibrissae, a progressive biomarker of the mineralization, by computerized morphometry of histopathologic sections and by direct chemical assay of calcium. We found that ETD, but not AST, at the 12x dosage, significantly reduced mineralization, suggesting that selected bisphosphonates may be helpful for prevention of mineral deposits in PXE and GACI caused by mutations in the ABCC6 gene, when combined with careful monitoring of efficacy and potential side-effects.
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Affiliation(s)
- Qiaoli Li
- a Department of Dermatology and Cutaneous Biology; Sidney Kimmel Medical College ; Thomas Jefferson University ; Philadelphia , PA USA
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49
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ENPP1-Fc prevents mortality and vascular calcifications in rodent model of generalized arterial calcification of infancy. Nat Commun 2015; 6:10006. [PMID: 26624227 PMCID: PMC4686714 DOI: 10.1038/ncomms10006] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 10/23/2015] [Indexed: 12/02/2022] Open
Abstract
Diseases of ectopic calcification of the vascular wall range from lethal orphan diseases such as generalized arterial calcification of infancy (GACI), to common diseases such as hardening of the arteries associated with aging and calciphylaxis of chronic kidney disease (CKD). GACI is a lethal orphan disease in which infants calcify the internal elastic lamina of their medium and large arteries and expire of cardiac failure as neonates, while calciphylaxis of CKD is a ubiquitous vascular calcification in patients with renal failure. Both disorders are characterized by vascular Mönckeburg's sclerosis accompanied by decreased concentrations of plasma inorganic pyrophosphate (PPi). Here we demonstrate that subcutaneous administration of an ENPP1-Fc fusion protein prevents the mortality, vascular calcifications and sequela of disease in animal models of GACI, and is accompanied by a complete clinical and biomarker response. Our findings have implications for the treatment of rare and common diseases of ectopic vascular calcification. Generalized arterial calcification of infancy (GACI) is a terminal disease caused by the ENPP1 enzyme deficiency. Here, Albrigh et al. show that ENPP1 enzyme replacement therapy prevents the ectopic calcifications and mortality in mice with GACI, suggesting a novel treatment for vascular calcification in humans.
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50
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Andelfinger G, Loeys B, Dietz H. A Decade of Discovery in the Genetic Understanding of Thoracic Aortic Disease. Can J Cardiol 2015; 32:13-25. [PMID: 26724507 DOI: 10.1016/j.cjca.2015.10.017] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 10/14/2015] [Accepted: 10/18/2015] [Indexed: 12/23/2022] Open
Abstract
Aortic aneurysms are responsible for a significant number of all deaths in Western countries. In this review we provide a perspective on the important progress made over the past decade in the understanding of the genetics of this condition, with an emphasis on the more frequent forms of vascular smooth muscle and transforming growth factor β (TGF-β) signalling alterations. For several nonsyndromic and syndromic forms of thoracic aortic disease, a genetic basis has now been identified, with 3 main pathomechanisms that have emerged: perturbation of the TGF-β signalling pathway, disruption of the vascular smooth muscle cell (VSMC) contractile apparatus, and impairment of extracellular matrix synthesis. Because smooth muscle cells and proteins of the extracellular matrix directly regulate TGF-β signalling, this latter pathway emerges as a key component of thoracic aortic disease initiation and progression. These discoveries have revolutionized our understanding of thoracic aortic disease and provided inroads toward gene-specific stratification of treatment. Last, we outline how these genetic findings are translated into novel pharmaceutical approaches for thoracic aortic disease.
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Affiliation(s)
- Gregor Andelfinger
- Cardiovascular Genetics, Department of Pediatrics, Centre de Recherche du Centre Hospitalier Universitaire Sainte-Justine, Université de Montréal, Montréal, Québec, Canada.
| | - Bart Loeys
- Centre for Medical Genetics, University Hospital of Antwerp/University of Antwerp, Antwerp, Belgium; Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Hal Dietz
- Howard Hughes Medical Institute and Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; Division of Pediatric Cardiology, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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