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Ansh AJ, Stabach PR, Ciccone C, Cao W, De La Cruz EM, Sabbagh Y, Carpenter TO, Ferreira CR, Braddock DT. Quantitative correlation of ENPP1 pathogenic variants with disease phenotype. Bone 2024:117136. [PMID: 38806089 DOI: 10.1016/j.bone.2024.117136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 04/07/2024] [Accepted: 05/24/2024] [Indexed: 05/30/2024]
Abstract
Ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) codes for a type 2 transmembrane glycoprotein which hydrolyzes extracellular phosphoanhydrides into bio-active molecules that regulate, inter alia, ectopic mineralization, bone formation, vascular endothelial proliferation, and the innate immune response. The clinical phenotypes produced by ENPP1 deficiency are disparate, ranging from life-threatening arterial calcifications to cutaneous hypopigmentation. To investigate associations between disease phenotype and enzyme activity we quantified the enzyme velocities of 29 unique ENPP1 pathogenic variants in 41 patients enrolled in an NIH study along with 33 other variants reported in literature. We correlated the relative enzyme velocities with the presenting clinical diagnoses, performing the catalytic velocity measurements simultaneously in triplicate using a high-throughput assay to reduce experimental variation. We found that ENPP1 variants associated with autosomal dominant phenotypes reduced enzyme velocities by 50 % or more, whereas variants associated with insulin resistance had non-significant effects on enzyme velocity. In Cole's disease the catalytic velocities of ENPP1 variants associated with AD forms trended to lower values than those associated with autosomal recessive forms - 8-32 % vs. 33 % of WT, respectively. Additionally, ENPP1 variants leading to life-threatening vascular calcifications in GACI patients had widely variable enzyme activities, ranging from no significant differences compared to WT to the complete abolishment of enzyme velocity. Finally, disease severity in GACI did not correlate with the mean enzyme velocity of the variants present in affected compound heterozygotes but did correlate with the more severely damaging variant. In summary, correlation of ENPP1 enzyme velocity with disease phenotypes demonstrate that enzyme velocities below 50 % of WT levels are likely to occur in the context of autosomal dominant disease (due to a monoallelic variant), and that disease severity in GACI infants correlates with the more severely damaging ENPP1 variant in compound heterozygotes, not the mean velocity of the pathogenic variants present.
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Affiliation(s)
- Anenya Jai Ansh
- 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
| | - Carla Ciccone
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Wenxiang Cao
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA
| | - Enrique M De La Cruz
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA
| | - Yves Sabbagh
- Inozyme Pharma, 321 Summer St., Suite 400, Boston, MA 02201, USA
| | - Thomas O Carpenter
- Department of Pediatrics (Endocrinology), Yale University School of Medicine, New Haven, CT, USA
| | - Carlos R Ferreira
- Metabolic Medicine Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Demetrios T Braddock
- Department of Pathology, Yale University School of Medicine, New Haven, CT, USA.
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Tourkova IL, Larrouture QC, Liu S, Luo J, Schlesinger PH, Blair HC. The ecto-nucleotide pyrophosphatase/phosphodiesterase 2 promotes early osteoblast differentiation and mineralization in stromal stem cells. Am J Physiol Cell Physiol 2024; 326:C843-C849. [PMID: 38223929 PMCID: PMC11193479 DOI: 10.1152/ajpcell.00692.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 01/08/2024] [Accepted: 01/10/2024] [Indexed: 01/16/2024]
Abstract
The phosphodiesterase enzymes mediate calcium-phosphate deposition in various tissues, although which enzymes are active in bone mineralization is unclear. Using gene array analysis, we found that a member of ecto-nucleotide pyrophosphatase/phosphodiesterase family, ENPP2, was strongly down-regulated with age in stromal stem cells that produce osteoblasts and make bone. This is in keeping with reduced bone formation in older animals. Thus, we hypothesized that ENPP2 is, at least in part, an early mediator of bone formation and thus may reflect reduced bone formation with age. Since ENPP2 has not previously been shown to have a role in osteoblast differentiation, we studied its effect on bone differentiation from stromal stem cells, verified by flow cytometry for stem cell antigens. In these remarkably uniform osteoblast precursors, we did transfection with ENPP2 DsiRNA, scrambled DsiRNA, or no transfection to make cells with normal or greatly reduced ENPP2 and analyzed osteoblast differentiation and mineralization. Osteoblast differentiation down-regulation was shown by alizarin red binding, silver staining, and alkaline phosphatase activity. Differences were confirmed by real-time PCR for alkaline phosphatase (ALPL), osteocalcin (BGLAP), and ENPP2 and by Western Blot for Enpp2. These were decreased, ∼50%, in osteoblasts transfected with ENPP2 DsiRNA compared with cells transfected with a scrambled DsiRNA or not transfected (control) cells. This finding is the first evidence for the role of ENPP2 in osteoblast differentiation and mineralization.NEW & NOTEWORTHY We report the discovery that the ecto-nucleotide pyrophosphatase/phosphodiesterase, ENPP2, is an important regulator of early differentiation of bone-forming osteoblasts.
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Affiliation(s)
- Irina L Tourkova
- Research Service, VA Medical Centre, Pittsburgh, Pennsylvania, United States
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Quitterie C Larrouture
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Silvia Liu
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Jianhua Luo
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Paul H Schlesinger
- Department of Cell Biology, Washington University, St. Louis, Missouri, United States
| | - Harry C Blair
- Research Service, VA Medical Centre, Pittsburgh, Pennsylvania, United States
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
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3
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Ferreira CR, Carpenter TO, Braddock DT. ENPP1 in Blood and Bone: Skeletal and Soft Tissue Diseases Induced by ENPP1 Deficiency. ANNUAL REVIEW OF PATHOLOGY 2024; 19:507-540. [PMID: 37871131 PMCID: PMC11062289 DOI: 10.1146/annurev-pathmechdis-051222-121126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
The enzyme ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) codes for a type 2 transmembrane glycoprotein that hydrolyzes extracellular ATP to generate pyrophosphate (PPi) and adenosine monophosphate, thereby contributing to downstream purinergic signaling pathways. The clinical phenotypes induced by ENPP1 deficiency are seemingly contradictory and include early-onset osteoporosis in middle-aged adults and life-threatening vascular calcifications in the large arteries of infants with generalized arterial calcification of infancy. The progressive overmineralization of soft tissue and concurrent undermineralization of skeleton also occur in the general medical population, where it is referred to as paradoxical mineralization to highlight the confusing pathophysiology. This review summarizes the clinical presentation and pathophysiology of paradoxical mineralization unveiled by ENPP1 deficiency and the bench-to-bedside development of a novel ENPP1 biologics designed to treat mineralization disorders in the rare disease and general medical population.
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Affiliation(s)
- Carlos R Ferreira
- Metabolic Medicine Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Thomas O Carpenter
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Demetrios T Braddock
- Department of Pathology, Yale University School of Medicine, New Haven, Connecticut, USA;
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4
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Kato H, Braddock DT, Ito N. Genetics of Diffuse Idiopathic Skeletal Hyperostosis and Ossification of the Spinal Ligaments. Curr Osteoporos Rep 2023; 21:552-566. [PMID: 37530996 PMCID: PMC10543536 DOI: 10.1007/s11914-023-00814-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/03/2023] [Indexed: 08/03/2023]
Abstract
PURPOSE OF REVIEW The study aims to provide updated information on the genetic factors associated with the diagnoses 'Diffuse Idiopathic Skeletal Hyperostosis' (DISH), 'Ossification of the Posterior Longitudinal Ligament' (OPLL), and in patients with spinal ligament ossification. RECENT FINDINGS Recent studies have advanced our knowledge of genetic factors associated with DISH, OPLL, and other spinal ossification (ossification of the anterior longitudinal ligament [OALL] and the yellow ligament [OYL]). Several case studies of individuals afflicted with monogenic disorders, such as X-linked hypophosphatemia (XLH), demonstrate the strong association of fibroblast growth factor 23-related hypophosphatemia with OPLL, suggesting that pathogenic variants in PHEX, ENPP1, and DMP1 are associated with FGF23-phosphate wasting phenotype and strong genetic factors placing patients at risk for OPLL. Moreover, emerging evidence demonstrates that heterozygous and compound heterozygous ENPP1 pathogenic variants inducing 'Autosomal Recessive Hypophosphatemic Rickets Type 2' (ARHR2) also place patients at risk for DISH and OPLL, possibly due to the loss of inhibitory plasma pyrophosphate (PPi) which suppresses ectopic calcification and enthesis mineralization. Our findings emphasize the importance of genetic and plasma biomarker screening in the clinical evaluation of DISH and OPLL patients, with plasma PPi constituting an important new biomarker for the identification of DISH and OPLL patients whose disease course may be responsive to ENPP1 enzyme therapy, now in clinical trials for rare calcification disorders.
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Affiliation(s)
- Hajime Kato
- Division of Nephrology and Endocrinology, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-Ku, Tokyo, 113-8655, Japan
- Osteoporosis Center, The University of Tokyo Hospital, Tokyo, Japan
| | | | - Nobuaki Ito
- Division of Nephrology and Endocrinology, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-Ku, Tokyo, 113-8655, Japan.
- Osteoporosis Center, The University of Tokyo Hospital, Tokyo, Japan.
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5
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Khursigara G, Huertas P, Wenkert D, O'Brien K, Sabbagh Y. Effects of food, fasting, and exercise on plasma pyrophosphate levels and ENPP1 activity in healthy adults. Bone 2023; 171:116750. [PMID: 37003563 DOI: 10.1016/j.bone.2023.116750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 03/21/2023] [Accepted: 03/23/2023] [Indexed: 04/01/2023]
Abstract
BACKGROUND Inorganic pyrophosphate (PPi) is highly regulated as it plays a critical role in the regulation of physiological mineralization. Dysregulation of plasma PPi is associated with skeletal hypomineralization and pathogenic mineralization in soft connective tissue, arteries, and heart valves. There is no standard approach to measuring PPi, making it difficult to establish PPi as a biomarker of mineralization disorders. This study aims to determine the impact of time of day, meals, or exercise on plasma PPi homeostasis using a highly sensitive PPi assay. METHODS In this single-center trial, a clinical laboratory improvement amendment (CLIA) validated modified sulfurylase-based adenosine 5-triphosphate (ATP) assay was used to measure PPi levels throughout the day in 10 healthy adults under 3 conditions; normal diet (non-fasting), fasting, and normal diet with exercise. Serum ectonucleotide pyrophosphatase/phosphodiesterase 1 activity (ENPP1; an enzyme that produces PPi) was also measured to determine whether these conditions influence PPi levels through ENPP1 activity. RESULTS There is a circadian increase in mean PPi levels under fasting and non-fasting conditions between 8 am and 6 pm, followed by a rapid return to baseline overnight. A circadian increase in ENPP1 activity was also measured under fasting but was lost under non-fasting conditions. Meals increased the individual variability of PPi levels when compared to the same individual fasting. PPi levels and ENPP1 activity exhibited a short-term increase after intense exercise. We found PPi ranges from 1465 nM to 2969 nM (mean 2164 nM) after fasting overnight. Within this range, there was lower intra-subject variability in PPi, suggesting that each individual has a uniquely regulated normal PPi range. CONCLUSION Plasma levels of PPi can be reliably measured after an overnight fast and show promise as a biomarker of mineralization disorders.
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Affiliation(s)
- Gus Khursigara
- Inozyme Pharma, 321 Summer St, Suite 400, Boston, MA 02201, United States of America.
| | - Pedro Huertas
- Inozyme Pharma, 321 Summer St, Suite 400, Boston, MA 02201, United States of America
| | - Deborah Wenkert
- Inozyme Pharma, 321 Summer St, Suite 400, Boston, MA 02201, United States of America
| | - Kevin O'Brien
- Inozyme Pharma, 321 Summer St, Suite 400, Boston, MA 02201, United States of America
| | - Yves Sabbagh
- Inozyme Pharma, 321 Summer St, Suite 400, Boston, MA 02201, United States of America
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6
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Ralph D, Levine M, Millán JL, Uitto J, Li Q. Weighing the Evidence for the Roles of Plasma Versus Local Pyrophosphate in Ectopic Calcification Disorders. J Bone Miner Res 2023; 38:457-463. [PMID: 36807615 PMCID: PMC10365072 DOI: 10.1002/jbmr.4791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 02/02/2023] [Accepted: 02/16/2023] [Indexed: 02/22/2023]
Abstract
Ectopic calcification is characterized by inappropriate deposition of calcium mineral in nonskeletal connective tissues and can cause significant morbidity and mortality, particularly when it affects the cardiovascular system. Identification of the metabolic and genetic determinants of ectopic calcification could help distinguish individuals at the greatest risk of developing these pathological calcifications and could guide development of medical interventions. Inorganic pyrophosphate (PPi ) has long been recognized as the most potent endogenous inhibitor of biomineralization. It has been intensively studied as both a marker and a potential therapeutic for ectopic calcification. Decreased extracellular concentrations of PPi have been proposed to be a unifying pathophysiological mechanism for disorders of ectopic calcification, both genetic and acquired. However, are reduced plasma concentrations of PPi a reliable predictor of ectopic calcification? This perspective article evaluates the literature in favor and against a pathophysiological role of plasma versus tissue PPi dysregulation as a determinant of, and as a biomarker for, ectopic calcification. © 2023 American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Douglas Ralph
- Genetics, Genomics and Cancer Biology Ph.D. Program, Jefferson College of Life Sciences, Thomas Jefferson University, Philadelphia, PA, USA.,Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, PA, USA.,PXE International Center of Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, PA, USA
| | - Michael Levine
- Division of Endocrinology, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - José Luis Millán
- Sanford Children's Health Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Jouni Uitto
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, PA, USA.,PXE International Center of Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, PA, USA
| | - Qiaoli Li
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, PA, USA.,PXE International Center of Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, PA, USA
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7
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Morikane S, Ishida K, Taniguchi T, Ashizawa N, Matsubayashi M, Kurita N, Kobashi S, Iwanaga T. Identification of a DBA/2 Mouse Sub-strain as a Model for Pseudoxanthoma Elasticum-Like Tissue Calcification. Biol Pharm Bull 2023; 46:1737-1744. [PMID: 38044132 DOI: 10.1248/bpb.b23-00478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
Ectopic calcification in the cardiovascular system adversely affects life prognosis. DBA/2 mice experience calcification owing to low expression of Abcc6 as observed in pseudoxanthoma elasticum (PXE) patients; however, little is known about its characteristics as a calcification model. In this study, we explore the suitability of a DBA/2 sub-strain as a PXE-like tissue calcification model, and the effect of a bisphosphonate which prevents calcification of soft tissues in hypercalcemic models was evaluated. The incidence of calcification of the heart was compared among several sub-strains and between both sexes of DBA/2 mice. mRNA expression of calcification-related genes was compared with DBA/2 sub-strains and other mouse strains. In addition, progression of calcification and calciprotein particle formation in serum were examined. Among several sub-strains of DBA/2 mice, male DBA/2CrSlc mice showed the most remarkable cardiac calcification. In DBA/2CrSlc mice, expression of the anti-calcifying genes Abcc6, Enpp1 and Spp1 was lower than that in C57BL/6J, and expression of Enpp1 and Spp1 was lower compared with other sub-strains. Calcification was accompanied by accelerated formation of calciprotein particle, which was prevented by daily treatment with bisphosphonate. A model suitable for ectopic calcification was identified by choosing a sub-strain of DBA/2 mice, in which genetic characteristics would contribute to extended calcification.
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Abstract
Hypophosphatemic rickets typically presents in infancy or early childhood with skeletal deformities and growth plate abnormalities. The most common causes are genetic (such as X-linked hypophosphatemia), and these typically will result in lifelong hypophosphatemia and osteomalacia. Knowledge of phosphate metabolism, including the effects of fibroblast growth factor 23 (FGF23) (an osteocyte produced hormone that downregulates renal phosphate reabsorption and 1,25-dihydroxyvitamin-D (1,25(OH)2D) production), is critical to determining the underlying genetic or acquired causes of hypophosphatemia and to facilitate appropriate treatment. Serum phosphorus should be measured in any child or adult with musculoskeletal complaints suggesting rickets or osteomalacia. Clinical evaluation incudes thorough history, physical examination, laboratory investigations, genetic analysis (especially in the absence of a guiding family history), and imaging to establish etiology and to monitor severity and treatment course. The treatment depends on the underlying cause, but often includes active forms of vitamin D combined with phosphate salts, or anti-FGF23 antibody treatment (burosumab) for X-linked hypophosphatemia. The purpose of this article is to explore the approach to evaluating hypophosphatemic rickets and its treatment options.
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Affiliation(s)
- Sarah A Ackah
- Department of Medicine, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Erik A Imel
- Department of Medicine, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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9
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Chunn LM, Bissonnette J, Heinrich SV, Mercurio SA, Kiel MJ, Rutsch F, Ferreira CR. Estimation of ENPP1 deficiency genetic prevalence using a comprehensive literature review and population databases. Orphanet J Rare Dis 2022; 17:421. [PMID: 36461014 PMCID: PMC9717445 DOI: 10.1186/s13023-022-02577-2] [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: 08/08/2022] [Accepted: 11/20/2022] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND ENPP1 Deficiency-caused by biallelic variants in ENPP1-leads to widespread arterial calcification in early life (Generalized Arterial Calcification of Infancy, GACI) or hypophosphatemic rickets in later life (Autosomal Recessive Hypophosphatemic Rickets type 2, ARHR2). A prior study using the Exome Aggregation Consortium (ExAC)-a database of exomes obtained from approximately 60,000 individuals-estimated the genetic prevalence at approximately 1 in 200,000 pregnancies. METHODS We estimated the genetic prevalence of ENPP1 Deficiency by evaluating allele frequencies from a population database, assuming Hardy-Weinberg equilibrium. This estimate benefitted from a comprehensive literature review using Mastermind ( https://mastermind.genomenon.com/ ), which uncovered additional variants and supporting evidence, a larger population database with approximately 140,000 individuals, and improved interpretation of variants as per current clinical guidelines. RESULTS We estimate a genetic prevalence of approximately 1 in 64,000 pregnancies, thus more than tripling the prior estimate. In addition, the carrier frequency of ENPP1 variants was found to be highest in East Asian populations, albeit based on a small sample. CONCLUSION These results indicate that a significant number of patients with ENPP1 Deficiency remain undiagnosed. Efforts to increase disease awareness as well as expand genetic testing, particularly in non-European populations are warranted, especially now that clinical trials for enzyme replacement therapy, which proved successful in animal models, are underway.
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Affiliation(s)
| | | | | | | | | | - Frank Rutsch
- grid.16149.3b0000 0004 0551 4246Department of General Paediatrics, Muenster University Children’s Hospital, Münster, Germany
| | - Carlos R. Ferreira
- grid.280128.10000 0001 2233 9230Metabolic Medicine Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD USA
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10
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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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11
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Yang K, Li J, Tao L. Purine metabolism in the development of osteoporosis. Biomed Pharmacother 2022; 155:113784. [DOI: 10.1016/j.biopha.2022.113784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 09/27/2022] [Accepted: 09/28/2022] [Indexed: 11/17/2022] Open
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12
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Zimmerman K, Li X, von Kroge S, Stabach P, Lester ER, Chu EY, Srivastava S, Somerman MJ, Tommasini SM, Busse B, Schinke T, Carpenter TO, Oheim R, Braddock DT. Catalysis-Independent ENPP1 Protein Signaling Regulates Mammalian Bone Mass. J Bone Miner Res 2022; 37:1733-1749. [PMID: 35773783 PMCID: PMC9709593 DOI: 10.1002/jbmr.4640] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 06/09/2022] [Accepted: 06/17/2022] [Indexed: 11/06/2022]
Abstract
Biallelic ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) deficiency induces vascular/soft tissue calcifications in generalized arterial calcification of infancy (GACI), and low bone mass with phosphate-wasting rickets in GACI survivors (autosomal hypophosphatemic rickets type-2). ENPP1 haploinsufficiency induces early-onset osteoporosis and mild phosphate wasting in adults. Both conditions demonstrate the unusual combination of reduced accrual of skeletal mineral, yet excess and progressive heterotopic mineralization. ENPP1 is the only enzyme that generates extracellular pyrophosphate (PPi), a potent inhibitor of both bone and heterotopic mineralization. Life-threatening vascular calcification in ENPP1 deficiency is due to decreased plasma PPi; however, the mechanism by which osteopenia results is not apparent from an understanding of the enzyme's catalytic activity. To probe for catalysis-independent ENPP1 pathways regulating bone, we developed a murine model uncoupling ENPP1 protein signaling from ENPP1 catalysis, Enpp1T238A mice. In contrast to Enpp1asj mice, which lack ENPP1, Enpp1T238A mice have normal trabecular bone microarchitecture and favorable biomechanical properties. However, both models demonstrate low plasma Pi and PPi, increased fibroblast growth factor 23 (FGF23), and by 23 weeks, osteomalacia demonstrating equivalent phosphate wasting in both models. Reflecting findings in whole bone, calvarial cell cultures from Enpp1asj mice demonstrated markedly decreased calcification, elevated transcription of Sfrp1, and decreased nuclear β-catenin signaling compared to wild-type (WT) and Enpp1T238A cultures. Finally, the decreased calcification and nuclear β-catenin signaling observed in Enpp1asj cultures was restored to WT levels by knockout of Sfrp1. Collectively, our findings demonstrate that catalysis-independent ENPP1 signaling pathways regulate bone mass via the expression of soluble Wnt inhibitors such as secreted frizzled-related protein 1 (SFRP1), whereas catalysis dependent pathways regulate phosphate homeostasis through the regulation of plasma FGF23. © 2022 American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Kristin Zimmerman
- Department of Pathology, Yale University School of Medicine, New Haven Connecticut, 06510
| | - Xiaochen Li
- Department of Pathology, Yale University School of Medicine, New Haven Connecticut, 06510
| | - Simon von Kroge
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 22529 Hamburg, Germany
| | - Paul Stabach
- Department of Pathology, Yale University School of Medicine, New Haven Connecticut, 06510
| | - Ethan R. Lester
- Department of Pathology, Yale University School of Medicine, New Haven Connecticut, 06510
| | - Emily Y. Chu
- National Institute of Dental and Craniofacial Research (NIDCR), National Institutes of Health (NIH), Bethesda, MD, USA
- Department of General Dentistry, Operative Division, University of Maryland School of Dentistry, Baltimore, Maryland, 21202
| | - Shivani Srivastava
- Department of Pathology, Yale University School of Medicine, New Haven Connecticut, 06510
| | - Martha J. Somerman
- National Institute of Dental and Craniofacial Research (NIDCR), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Steven M. Tommasini
- Department of Orthopædics and Rehabilitation, Yale University School of Medicine, New Haven Connecticut, 06510
| | - Björn Busse
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 22529 Hamburg, Germany
| | - Thorsten Schinke
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 22529 Hamburg, Germany
| | - Thomas O. Carpenter
- Department of Pediatrics at Yale University School of Medicine, New Haven Connecticut, 06510
| | - Ralf Oheim
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 22529 Hamburg, Germany
| | - Demetrios T. Braddock
- Department of Pathology, Yale University School of Medicine, New Haven Connecticut, 06510
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Ralph D, Levine MA, Richard G, Morrow M, Flynn E, Uitto J, Li Q. Mutation update: Variants of the ENPP1 gene in pathologic calcification, hypophosphatemic rickets, and cutaneous hypopigmentation with punctate keratoderma. Hum Mutat 2022; 43:1183-1200. [PMID: 35475527 PMCID: PMC9357117 DOI: 10.1002/humu.24391] [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] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 04/07/2022] [Accepted: 04/22/2022] [Indexed: 11/11/2022]
Abstract
ENPP1 encodes ENPP1, an ectonucleotidase catalyzing hydrolysis of ATP to AMP and inorganic pyrophosphate (PPi), and an endogenous plasma protein physiologically preventing ectopic calcification of connective tissues. Mutations in ENPP1 have been reported in association with a range of human genetic diseases. In this mutation update, we provide a comprehensive review of all the pathogenic variants, likely pathogenic variants, and variants of unknown significance in ENPP1 associated with three autosomal recessive disorders-generalized arterial calcification of infancy (GACI), autosomal recessive hypophosphatemic rickets type 2 (ARHR2), and pseudoxanthoma elasticum (PXE), as well as with a predominantly autosomal dominant disorder-Cole disease. The classification of all variants is determined using the latest ACMG guidelines. A total of 140 ENPP1 variants were curated consisting of 133 previously reported variants and seven novel variants, with missense variants being the most prevalent (70.0%, 98/140). While the pathogenic variants are widely distributed in the ENPP1 gene of patientsgen without apparent genotype-phenotype correlation, eight out of nine variants associated with Cole disease are confined to the somatomedin-B-like (SMB) domains critical for homo-dimerization of the ENPP1 protein.
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Affiliation(s)
- Douglas Ralph
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, PA
- Genetics, Genomics and Cancer Biology Ph.D. Program, Jefferson College of Life Sciences, Thomas Jefferson University, Philadelphia, PA
- PXE International Center of Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, PA
| | - Michael A. Levine
- Division of Endocrinology and Diabetes, Children’s Hospital of Philadelphia, Philadelphia, PA
| | | | | | | | - Jouni Uitto
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, PA
- PXE International Center of Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, PA
| | - Qiaoli Li
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, PA
- PXE International Center of Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, PA
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14
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Oheim R, Tsourdi E, Seefried L, Beller G, Schubach M, Vettorazzi E, Stürznickel J, Rolvien T, Ehmke N, Delsmann A, Genest F, Krüger U, Zemojtel T, Barvencik F, Schinke T, Jakob F, Hofbauer LC, Mundlos S, Kornak U. Genetic Diagnostics in Routine Osteological Assessment of Adult Low Bone Mass Disorders. J Clin Endocrinol Metab 2022; 107:e3048-e3057. [PMID: 35276006 PMCID: PMC9202726 DOI: 10.1210/clinem/dgac147] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Indexed: 12/17/2022]
Abstract
CONTEXT Many different inherited and acquired conditions can result in premature bone fragility/low bone mass disorders (LBMDs). OBJECTIVE We aimed to elucidate the impact of genetic testing on differential diagnosis of adult LBMDs and at defining clinical criteria for predicting monogenic forms. METHODS Four clinical centers broadly recruited a cohort of 394 unrelated adult women before menopause and men younger than 55 years with a bone mineral density (BMD) Z-score < -2.0 and/or pathological fractures. After exclusion of secondary causes or unequivocal clinical/biochemical hallmarks of monogenic LBMDs, all participants were genotyped by targeted next-generation sequencing. RESULTS In total, 20.8% of the participants carried rare disease-causing variants (DCVs) in genes known to cause osteogenesis imperfecta (COL1A1, COL1A2), hypophosphatasia (ALPL), and early-onset osteoporosis (LRP5, PLS3, and WNT1). In addition, we identified rare DCVs in ENPP1, LMNA, NOTCH2, and ZNF469. Three individuals had autosomal recessive, 75 autosomal dominant, and 4 X-linked disorders. A total of 9.7% of the participants harbored variants of unknown significance. A regression analysis revealed that the likelihood of detecting a DCV correlated with a positive family history of osteoporosis, peripheral fractures (> 2), and a high normal body mass index (BMI). In contrast, mutation frequencies did not correlate with age, prevalent vertebral fractures, BMD, or biochemical parameters. In individuals without monogenic disease-causing rare variants, common variants predisposing for low BMD (eg, in LRP5) were overrepresented. CONCLUSION The overlapping spectra of monogenic adult LBMD can be easily disentangled by genetic testing and the proposed clinical criteria can help to maximize the diagnostic yield.
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Affiliation(s)
- Ralf Oheim
- Ralf Oheim, MD, Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestraße 59, 22529 Hamburg, Germany.
| | - Elena Tsourdi
- Department of Medicine III, Technische Universität Dresden Medical Center, 01307 Dresden, Germany
- Center for Healthy Aging, Technische Universität Dresden Medical Center, 01307 Dresden, Germany
| | - Lothar Seefried
- Orthopedic Center for Musculoskeletal Research, Orthopedic Department, University of Würzburg, 97070 Würzburg, Germany
| | - Gisela Beller
- Centre of Muscle and Bone Research, Charité-Universitätsmedizin Berlin, 13353 Berlin, Germany
| | - Max Schubach
- Berlin Institute of Health at Charité – Universitätsmedizin Berlin, 13353 Berlin, Germany
| | - Eik Vettorazzi
- Department of Medical Biometry and Epidemiology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Julian Stürznickel
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 22529 Hamburg, Germany
- Department of Orthopaedics and Trauma Surgery, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Tim Rolvien
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 22529 Hamburg, Germany
- Department of Orthopaedics and Trauma Surgery, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Nadja Ehmke
- Institute of Medical Genetics and Human Genetics, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, 13353 Berlin, Germany
| | - Alena Delsmann
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 22529 Hamburg, Germany
| | - Franca Genest
- Orthopedic Center for Musculoskeletal Research, Orthopedic Department, University of Würzburg, 97070 Würzburg, Germany
| | - Ulrike Krüger
- Core Facility Genomics, Berlin Institute of Health (BIH), 10178 Berlin, Germany
| | - Tomasz Zemojtel
- Core Facility Genomics, Berlin Institute of Health (BIH), 10178 Berlin, Germany
| | - Florian Barvencik
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 22529 Hamburg, Germany
| | - Thorsten Schinke
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 22529 Hamburg, Germany
| | - Franz Jakob
- Orthopedic Center for Musculoskeletal Research, Orthopedic Department, University of Würzburg, 97070 Würzburg, Germany
| | - Lorenz C Hofbauer
- Department of Medicine III, Technische Universität Dresden Medical Center, 01307 Dresden, Germany
- Center for Healthy Aging, Technische Universität Dresden Medical Center, 01307 Dresden, Germany
| | - Stefan Mundlos
- Institute of Medical Genetics and Human Genetics, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, 13353 Berlin, Germany
- BIH Center for Regenerative Therapies, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, 10178 Berlin, Germany
- Max Planck Institute for Molecular Genetics, 14195 Berlin, Germany
| | - Uwe Kornak
- Correspondence: Uwe Kornak, PhD, Institute of Human Genetics, Universitätsmedizin Göttingen, Heinrich-Düker-Weg 12, 37073 Göttingen, Germany.
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15
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Kato H, Ansh AJ, Lester ER, Kinoshita Y, Hidaka N, Hoshino Y, Koga M, Taniguchi Y, Uchida T, Yamaguchi H, Niida Y, Nakazato M, Nangaku M, Makita N, Takamura T, Saito T, Braddock DT, Ito N. Identification of ENPP1 Haploinsufficiency in Patients With Diffuse Idiopathic Skeletal Hyperostosis and Early-Onset Osteoporosis. J Bone Miner Res 2022; 37:1125-1135. [PMID: 35340077 PMCID: PMC9177665 DOI: 10.1002/jbmr.4550] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 03/14/2022] [Accepted: 03/21/2022] [Indexed: 11/10/2022]
Abstract
Homozygous ENPP1 mutations are associated with autosomal recessive hypophosphatemic rickets type 2 (ARHR2), severe ossification of the spinal ligaments, and generalized arterial calcification of infancy type 1. There are a limited number of reports on phenotypes associated with heterozygous ENPP1 mutations. Here, we report a series of three probands and their families with heterozygous and compound heterozygous ENPP1 mutations. The first case (case 1) was a 47-year-old male, diagnosed with early-onset osteoporosis and low-normal serum phosphate levels, which invoked suspicion for hypophosphatemic rickets. The second and third cases were 77- and 54-year-old females who both presented with severe spinal ligament ossification and the presumptive diagnosis of diffuse idiopathic skeletal hyperostosis (DISH). Upon workup, fibroblast growth factor 23 (FGF23) was noted to be relatively high in case 2 and serum phosphorous was low-normal in case 3, and the diagnoses of X-linked hypophosphatemic rickets (XLH) and ARHR2 were considered. Genetic testing for genes related to congenital hypophosphatemic rickets was therefore performed, revealing heterozygous ENPP1 variants in cases 1 and 2 (case 1, c.536A>G, p.Asn179Ser; case 2, c.1352A>G, p.Tyr451Cys) and compound heterozygous ENPP1 variants in case 3 constituting the same variants present in cases 1 and 2 (c.536A>G, p.Asn179Ser and c.1352A>G, p.Tyr451Cys). Several in silico tools predicted the two variants to be pathogeneic, a finding confirmed by in vitro biochemical analysis demonstrating that the p.Asn179Ser and p.Tyr451Cys ENPP1 variants possessed a catalytic velocity of 45% and 30% compared with that of wild-type ENPP1, respectively. Both variants were therefore categorized as pathogenic loss-of-function mutations. Our findings suggest that ENPP1 mutational status should be evaluated in patients presenting with the diagnosis of idiopathic DISH, ossification of the posterior longitudinal ligament (OPLL), and early-onset osteoporosis. © 2022 American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Hajime Kato
- Division of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo, Japan
- Osteoporosis center, The University of Tokyo Hospital, Tokyo, Japan
| | - Anenya J. Ansh
- Department of Pathology, Yale University, New Haven, CT, USA
| | - Ethan R. Lester
- Department of Pathology, Yale University, New Haven, CT, USA
| | - Yuka Kinoshita
- Division of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo, Japan
- Osteoporosis center, The University of Tokyo Hospital, Tokyo, Japan
| | - Naoko Hidaka
- Division of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo, Japan
- Osteoporosis center, The University of Tokyo Hospital, Tokyo, Japan
| | - Yoshitomo Hoshino
- Division of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo, Japan
- Osteoporosis center, The University of Tokyo Hospital, Tokyo, Japan
| | - Minae Koga
- Division of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo, Japan
- Osteoporosis center, The University of Tokyo Hospital, Tokyo, Japan
| | - Yuki Taniguchi
- Department of Orthopedic Surgery, The University of Tokyo Hospital, Tokyo, Japan
| | - Taisuke Uchida
- Division of Neurology, Respirology, Endocrinology and Metabolism, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan
| | - Hideki Yamaguchi
- Division of Neurology, Respirology, Endocrinology and Metabolism, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan
| | - Yo Niida
- Division of Genomic Medicine, Department of Advanced Medicine, Medical Research Institute, Kanazawa Medical University, Ishikawa, Japan
| | - Masamitsu Nakazato
- Division of Neurology, Respirology, Endocrinology and Metabolism, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan
| | - Masaomi Nangaku
- Division of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo, Japan
| | - Noriko Makita
- Division of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo, Japan
- Osteoporosis center, The University of Tokyo Hospital, Tokyo, Japan
| | - Toshinari Takamura
- Department of Endocrinology and Metabolism, Kanazawa University Graduate School of Medical Sciences, Ishikawa, Japan
| | - Taku Saito
- Osteoporosis center, The University of Tokyo Hospital, Tokyo, Japan
- Department of Orthopedic Surgery, The University of Tokyo Hospital, Tokyo, Japan
| | | | - Nobuaki Ito
- Division of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo, Japan
- Osteoporosis center, The University of Tokyo Hospital, Tokyo, Japan
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Nam HK, Emmanouil E, Hatch NE. Deletion of the Pyrophosphate Generating Enzyme ENPP1 Rescues Craniofacial Abnormalities in the TNAP−/− Mouse Model of Hypophosphatasia and Reveals FGF23 as a Marker of Phenotype Severity. FRONTIERS IN DENTAL MEDICINE 2022; 3. [PMID: 35909501 PMCID: PMC9336114 DOI: 10.3389/fdmed.2022.846962] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Hypophosphatasia is a rare heritable metabolic disorder caused by deficient Tissue Non-specific Alkaline Phosphatase (TNAP) enzyme activity. A principal function of TNAP is to hydrolyze the tissue mineralization inhibitor pyrophosphate. ENPP1 (Ectonucleotide Pyrophosphatase/Phosphodiesterase 1) is a primary enzymatic generator of pyrophosphate and prior results showed that elimination of ENPP1 rescued bone hypomineralization of skull, vertebral and long bones to different extents in TNAP null mice. Current TNAP enzyme replacement therapy alleviates skeletal, motor and cognitive defects but does not eliminate craniosynostosis in pediatric hypophosphatasia patients. To further understand mechanisms underlying craniosynostosis development in hypophosphatasia, here we sought to determine if craniofacial abnormalities including craniosynostosis and skull shape defects would be alleviated in TNAP null mice by genetic ablation of ENPP1. Results show that homozygous deletion of ENPP1 significantly diminishes the incidence of craniosynostosis and that skull shape abnormalities are rescued by hemi- or homozygous deletion of ENPP1 in TNAP null mice. Skull and long bone hypomineralization were also alleviated in TNAP−/−/ENPP1−/− compared to TNAP−/−/ENPP1+/+ mice, though loss of ENPP1 in combination with TNAP had different effects than loss of only TNAP on long bone trabeculae. Investigation of a relatively large cohort of mice revealed that the skeletal phenotypes of TNAP null mice were markedly variable. Because FGF23 circulating levels are known to be increased in ENPP1 null mice and because FGF23 influences bone, we measured serum intact FGF23 levels in the TNAP null mice and found that a subset of TNAP−/−/ENPP1+/+ mice exhibited markedly high serum FGF23. Serum FGF23 levels also correlated to mouse body measurements, the incidence of craniosynostosis, skull shape abnormalities and skull bone density and volume fraction. Together, our results demonstrate that balanced expression of TNAP and ENPP1 enzymes are essential for microstructure and mineralization of both skull and long bones, and for preventing craniosynostosis. The results also show that FGF23 rises in the TNAP−/− model of murine lethal hypophosphatasia. Future studies are required to determine if the rise in FGF23 is a cause, consequence, or marker of disease phenotype severity.
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17
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Furukawa H, Oka S, Kondo N, Nakagawa Y, Shiota N, Kumagai K, Ando K, Takeshita T, Oda T, Takahashi Y, Izawa K, Iwasaki Y, Hasegawa K, Arino H, Minamizaki T, Yoshikawa N, Takata S, Yoshihara Y, Tohma S. The Contribution of Deleterious Rare Alleles in ENPP1 and Osteomalacia Causative Genes to Atypical Femoral Fracture. J Clin Endocrinol Metab 2022; 107:e1890-e1898. [PMID: 35038731 DOI: 10.1210/clinem/dgac022] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Indexed: 11/19/2022]
Abstract
CONTEXT Atypical femoral fractures (AFFs) are very rare atraumatic or mild trauma fractures in the subtrochanteric region or femoral shaft. Some unique genetic variants in Asian populations might confer susceptibility to AFF, since the incidence of AFFs is higher in Asian populations. OBJECTIVE Because rare variants have been found to be causative in some diseases and the roles of osteomalacia causative genes have not been reported, we investigated rare variants in genes causing abnormal mineralization. METHODS Exome sequencing was performed to detect variants in gene coding and boundary regions, and the frequencies of deleterious rare alleles were compared between Japanese patients with AFF (n = 42) and controls of the 4.7KJPN panel of Tohoku Medical Megabank by whole genome sequencing (n = 4773). RESULTS The frequency of the deleterious rare allele of ENPP1 was significantly increased in AFF (P = .0012, corrected P [Pc] = .0155, OR 4.73, 95% CI 2.15-10.40). In multigene panel analysis, the frequencies of deleterious rare alleles of candidate genes were increased in AFF (P = .0025, OR 2.72, 95% CI 1.49-4.93). Principal component analysis of bone metabolism markers identified a subgroup of patients with AFF with higher frequencies of deleterious rare alleles in ENPP1 (P = 4.69 × 10-5, Pc = .0006, OR 8.47, 95% CI 3.76-19.09) and the candidate genes (P = 1.08 × 10-5, OR 5.21, 95% CI 2.76-9.86). CONCLUSION AFF is associated with genes including ENPP1 that cause abnormal mineralization, suggesting that osteomalacia is an underlying condition predisposing to AFF and that higher incident rates of AFFs in Asian populations might be explained by the genetic risk factors including ENPP1.
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Affiliation(s)
- Hiroshi Furukawa
- Department of Rheumatology, National Hospital Organization Tokyo National Hospital, Kiyose, 204-8585Japan
- Clinical Research Center for Allergy and Rheumatology, National Hospital Organization Sagamihara National Hospital, Minami-ku, Sagamihara, 252-0392Japan
| | - Shomi Oka
- Department of Rheumatology, National Hospital Organization Tokyo National Hospital, Kiyose, 204-8585Japan
- Clinical Research Center for Allergy and Rheumatology, National Hospital Organization Sagamihara National Hospital, Minami-ku, Sagamihara, 252-0392Japan
| | - Naoki Kondo
- Division of Orthopedic Surgery, Department of Regenerative and Transplant Medicine, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata, 951-8510Japan
| | - Yasuaki Nakagawa
- Department of Orthopedics, National Hospital Organization Kyoto Medical Center, Fushimi-ku, Kyoto, 612-8555, Japan
| | - Naofumi Shiota
- Department of Orthopedics/Rehabilitation, National Hospital Organization Okayama Medical Center, Kita-ku, Okayama, 701-1192, Japan
| | - Kenji Kumagai
- Department of Orthopedics, National Hospital Organization Nagasaki Medical Center, Omura, 856-8562, Japan
| | - Keiji Ando
- Department of Orthopedics, National Hospital Organization Utano National Hospital, Ukyo-ku, Kyoto, 616-8255Japan
| | - Tsutao Takeshita
- Department of Orthopedics, National Hospital Organization Beppu Medical Center, Beppu, 874-0011, Japan
| | - Takenori Oda
- Clinical Research Center, National Hospital Organization Osaka Minami Medical Center, Kawachinagano, 586-8521, Japan
| | - Yoshinori Takahashi
- Department of Orthopedics/Rehabilitation, National Hospital Organization Nishiniigata Chuo Hospital, Nishi-ku, Niigata, 950-2085Japan
- Bitoku Orthopedic Clinic, Chuo-ku, Niigata, 951-8067Japan
| | - Kazutaka Izawa
- Department of Orthopedics, National Hospital Organization Osaka Toneyama Medical Center, Toyonaka, 560-8552Japan
| | - Yoichi Iwasaki
- Department of Orthopedics, National Hospital Organization Hiroshima-Nishi Medical Center, Otake, 739-0696, Japan
- Department of Orthopedics/Rehabilitation, Hiroshima Hiramatsu Hospital, Minami-ku, Hiroshima, 739-0696, Japan
| | - Kazuhiro Hasegawa
- Department of Orthopedics, National Hospital Organization Kanazawa Medical Center, Kanazawa, 920-8650, Japan
- Niigata Spine Surgery Center, Kameda Daiichi Hospital, Konan-ku, Niigata, 950-0165, Japan
| | - Hiroshi Arino
- Department of Orthopedics, National Hospital Organization Tokyo Medical Center, Meguro-ku, Tokyo, 152-8902, Japan
- Department of Orthopedics, Ota Memorial Hospital, Ota, 373-8585, Japan
| | - Takeshi Minamizaki
- Department of Orthopedics, National Hospital Organization Yonago Medical Center, Yonago, 683-0006, Japan
| | - Norie Yoshikawa
- Department of Orthopedics, National Hospital Organization Miyakonojo Medical Center, Miyakonojo, 885-0014, Japan
| | - Shinjiro Takata
- Department of Orthopedics/Rehabilitation, National Hospital Organization Tokushima National Hospital, Yoshinogawa, 776-8585, Japan
| | - Yasuo Yoshihara
- Clinical Research Center, National Hospital Organization Murayama Medical Center, Musashimurayama, 208-0011, Japan
| | - Shigeto Tohma
- Department of Rheumatology, National Hospital Organization Tokyo National Hospital, Kiyose, 204-8585Japan
- Clinical Research Center for Allergy and Rheumatology, National Hospital Organization Sagamihara National Hospital, Minami-ku, Sagamihara, 252-0392Japan
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Ferreira CR, Ansh AJ, Nester C, O’Brien C, Stabach PR, Murtada SI, Lester ER, Khursigara G, Molloy L, Carpenter TO, Braddock DT. Musculoskeletal Comorbidities and Quality of Life in ENPP1-Deficient Adults and the Response of Enthesopathy to Enzyme Replacement Therapy in Murine Models. J Bone Miner Res 2022; 37:494-504. [PMID: 34882836 PMCID: PMC9667476 DOI: 10.1002/jbmr.4487] [Citation(s) in RCA: 10] [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] [Received: 07/23/2021] [Revised: 11/04/2021] [Accepted: 12/05/2021] [Indexed: 12/20/2022]
Abstract
Ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) deficiency leads to cardiovascular calcification in infancy, fibroblast growth factor 23 (FGF23)-mediated hypophosphatemic rickets in childhood, and osteomalacia in adulthood. Excessive enthesis mineralization and cervical spine fusion have been previously reported in patients with biallelic ENPP1 deficiency, but their effect on quality of life is unknown. We describe additional musculoskeletal complications in patients with ENPP1 deficiency, namely osteoarthritis and interosseous membrane ossification, and for the first time evaluate health-related quality of life (HRQoL) in patients with this disease, both subjectively via narrative report, and objectively via the Brief Pain Inventory-Short Form, and a Patient Reported Outcome Measurement Information System Physical Function (PROMIS PF) short form. Residual pain, similar in magnitude to that identified in adult patients with X-linked hypophosphatemia, was experienced by the majority of patients despite use of analgesic medications. Impairment in physical function varied from mild to severe. To assess murine ENPP1 deficiency for the presence of enthesopathy, and for the potential response to enzyme replacement therapy, we maintained Enpp1asj/asj mice on regular chow for 23 weeks and treated cohorts with either vehicle or a long-acting form of recombinant ENPP1. Enpp1asj/asj mice treated with vehicle exhibited robust calcification throughout their Achilles tendons, whereas two-thirds of those treated with ENPP1 enzyme replacement exhibited complete or partial suppression of the Achilles tendon calcification. Our combined results document that musculoskeletal complications are a significant source of morbidity in biallelic ENPP1 deficiency, a phenotype which is closely recapitulated in Enpp1asj/asj mice. Finally, we show that a long-acting form of recombinant ENPP1 prevents the development of enthesis calcification at the relatively modest dose of 0.3 mg/kg per week, suggesting that suppression of enthesopathy may be attainable upon dose escalation. © 2021 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
- Medical Genomics and Metabolic Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Anenya Jai Ansh
- 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
| | - Sae-Il Murtada
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA
| | - Ethan R. Lester
- Department of Pathology, Yale University School of Medicine, New Haven, CT, USA
| | | | | | - Thomas O. Carpenter
- Department of Pediatrics (Endocrinology), Yale University School of Medicine, New Haven, CT, USA
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Boneski PK, Madhu V, Tomlinson RE, Shapiro IM, van de Wetering K, Risbud MV. Abcc6 Null Mice—a Model for Mineralization Disorder PXE Shows Vertebral Osteopenia Without Enhanced Intervertebral Disc Calcification With Aging. Front Cell Dev Biol 2022; 10:823249. [PMID: 35186933 PMCID: PMC8850990 DOI: 10.3389/fcell.2022.823249] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Accepted: 01/03/2022] [Indexed: 12/12/2022] Open
Abstract
Chronic low back pain is a highly prevalent health condition intricately linked to intervertebral disc degeneration. One of the prominent features of disc degeneration that is commonly observed with aging is dystrophic calcification. ATP-binding cassette sub-family C member 6 (ABCC6), a presumed ATP efflux transporter, is a key regulator of systemic levels of the mineralization inhibitor pyrophosphate (PPi). Mutations in ABCC6 result in pseudoxanthoma elasticum (PXE), a progressive human metabolic disorder characterized by mineralization of the skin and elastic tissues. The implications of ABCC6 loss-of-function on pathological mineralization of structures in the spine, however, are unknown. Using the Abcc6−/− mouse model of PXE, we investigated age-dependent changes in the vertebral bone and intervertebral disc. Abcc6−/− mice exhibited diminished trabecular bone quality parameters at 7 months, which remained significantly lower than the wild-type mice at 18 months of age. Abcc6−/− vertebrae showed increased TRAP staining along with decreased TNAP staining, suggesting an enhanced bone resorption as well as decreased bone formation. Surprisingly, however, loss of ABCC6 resulted only in a mild, aging disc phenotype without evidence of dystrophic mineralization. Finally, we tested the utility of oral K3Citrate to treat the vertebral phenotype since it is shown to regulate hydroxyapatite mechanical behavior. The treatment resulted in inhibition of the osteoclastic response and an early improvement in mechanical properties of the bone underscoring the promise of potassium citrate as a therapeutic agent. Our data suggest that although ectopic mineralization is tightly regulated in the disc, loss of ABCC6 compromises vertebral bone quality and dysregulates osteoblast-osteoclast coupling.
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Affiliation(s)
- Paige K. Boneski
- Department of Orthopedic Surgery, Thomas Jefferson University, Philadelphia, PA, United States
| | - Vedavathi Madhu
- Department of Orthopedic Surgery, Thomas Jefferson University, Philadelphia, PA, United States
| | - Ryan E. Tomlinson
- Department of Orthopedic Surgery, Thomas Jefferson University, Philadelphia, PA, United States
| | - Irving M. Shapiro
- Department of Orthopedic Surgery, Thomas Jefferson University, Philadelphia, PA, United States
| | - Koen van de Wetering
- Department of Dermatology and Cutaneous Biology, Jefferson Institute of Molecular Medicine and PXE International Center of Excellence in Research and Clinical Care, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, United States
| | - Makarand V. Risbud
- Department of Orthopedic Surgery, Thomas Jefferson University, Philadelphia, PA, United States
- *Correspondence: Makarand V. Risbud,
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Choe Y, Shin CH, Lee YA, Kim MJ, Lee YJ. Case Report and Review of Literature: Autosomal Recessive Hypophosphatemic Rickets Type 2 Caused by a Pathogenic Variant in ENPP1 Gene. Front Endocrinol (Lausanne) 2022; 13:911672. [PMID: 35966073 PMCID: PMC9374118 DOI: 10.3389/fendo.2022.911672] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Accepted: 06/01/2022] [Indexed: 11/29/2022] Open
Abstract
Autosomal recessive hypophosphatemic rickets type 2 (ARHR2) is a rare form of hereditary rickets, which is characterized by defective bone mineralization and renal phosphate wasting due to a loss-of-function variant in the ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) gene. Although pathogenic variant of ENPP1 has been known to manifest other phenotypes including arterial calcification, hearing loss, ossification of posterior longitudinal ligament, or pseudoxanthoma elasticum, there have been few reports including systematic examination in individuals diagnosed with ARHR2 to date. Herein, we report a case of ARHR2 with a bi-allelic pathogenic variant of ENPP1, in which the patient presented with gait abnormalities with severe genu varum at 26 months of age. Targeted gene panel sequencing was performed to investigate the genetic cause of rickets, and a homozygous nonsense variant in ENPP1, c.783C>G (p.Tyr261*), was identified. The patient was treated with oral phosphate and active vitamin D supplements and underwent corrective osteotomy for varus deformity. His phenotype was limited to rickets. A periodic systematic evaluation is needed to identify any comorbidities in ARHR2 patients since ENPP1 variants may present phenotypes other than rickets and symptoms may evolve or change over time.
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Affiliation(s)
- Yunsoo Choe
- Department of Pediatrics, Seoul National University Children’s Hospital, Seoul, South Korea
| | - Choong Ho Shin
- Department of Pediatrics, Seoul National University Children’s Hospital, Seoul, South Korea
| | - Young Ah Lee
- Department of Pediatrics, Seoul National University Children’s Hospital, Seoul, South Korea
| | - Man Jin Kim
- Department of Genomic Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, South Korea
| | - Yun Jeong Lee
- Department of Pediatrics, Seoul National University Children’s Hospital, Seoul, South Korea
- *Correspondence: Yun Jeong Lee,
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21
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Höppner J, Kornak U, Sinningen K, Rutsch F, Oheim R, Grasemann C. Autosomal recessive hypophosphatemic rickets type 2 (ARHR2) due to ENPP1-deficiency. Bone 2021; 153:116111. [PMID: 34252603 DOI: 10.1016/j.bone.2021.116111] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 07/01/2021] [Accepted: 07/06/2021] [Indexed: 12/25/2022]
Abstract
Awareness for hypophosphatemic rickets has increased in the last years, based on the availability of specific medical treatments. Autosomal recessive hypophosphatemic rickets type 2 (ARHR2) is a rare form of hypophosphatemic rickets, which is known to develop in survivors of generalized arterial calcification of infancy (GACI). Both disorders are based on a deficiency of ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) and present with a high clinical variability and a lack of a phenotype-genotype association. ARHR2 is characterized by phosphate wasting due to elevated fibroblast growth factor 23 (FGF23) levels and might represent a response of the organism to minimize ectopic calcification in individuals with ENPP1-deficiency. This report reviews the recent clinical and preclinical data on this ultra-rare disease in childhood.
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Affiliation(s)
- Jakob Höppner
- Center for Rare Diseases Ruhr CeSER, Ruhr-University Bochum and Witten/Herdecke University, Germany; Department of Pediatrics, St.-Josef Hospital Bochum, Ruhr-University Bochum, Bochum, Germany
| | - Uwe Kornak
- Institute for Human Genetics, Universitätsmedizin Göttingen, Göttingen, Germany
| | - Kathrin Sinningen
- Department of Pediatrics, St.-Josef Hospital Bochum, Ruhr-University Bochum, Bochum, Germany
| | - Frank Rutsch
- Department of General Pediatrics, Münster University Children's Hospital, Münster, Germany
| | - Ralf Oheim
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Corinna Grasemann
- Center for Rare Diseases Ruhr CeSER, Ruhr-University Bochum and Witten/Herdecke University, Germany; Department of Pediatrics, St.-Josef Hospital Bochum, Ruhr-University Bochum, Bochum, Germany.
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22
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Vilmundarson RO, Duong A, Soheili F, Chen HH, Stewart AFR. IRF2BP2 3'UTR Polymorphism Increases Coronary Artery Calcification in Men. Front Cardiovasc Med 2021; 8:687645. [PMID: 34760935 PMCID: PMC8573268 DOI: 10.3389/fcvm.2021.687645] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 09/28/2021] [Indexed: 12/15/2022] Open
Abstract
Interferon regulatory factor 2 binding protein 2 (IRF2BP2) suppresses the innate inflammatory response of macrophages. A 9-nucleotide deletion (rs3045215) in the 3' untranslated region (3'-UTR) of human IRF2BP2 mRNA confers risk of coronary artery disease (CAD) in the Ottawa Heart Genomics Study (OHGS). Here, we sought to identify regulatory mechanisms that may contribute to this risk. We tested how lipopolysaccharides (LPS) affects IRF2BP2 expression in human THP-1 macrophages and primary aortic smooth muscle cells (HAoSMC) genotyped for the deletion allele. Both cell types are implicated in coronary atherosclerosis. We also examined how the deletion affects interaction with RNA binding proteins (RBPs) to regulate IRF2BP2 expression. LPS altered allele-specific binding of RBPs in RNA gel shift assays with the THP-1 macrophage protein extracts. The RBP ELAVL1 suppressed the expression of a luciferase reporter carrying the 3'UTR of IRF2BP2 with the deletion allele. Other RBPs AUF1 or KHSRP did not confer such allele specific regulation. Since it is co-inherited with a risk variant for osteoporosis, a condition tied to arterial calcification, we examined the association of the deletion allele with coronary artery calcification in individuals who had undergone computed tomography angiography in the OHGS. In 323 individuals with a minimal burden of atherosclerosis (<30% coronary stenosis) and 138 CAD cases (>50% stenosis), Mendelian randomization revealed that the rs3045215 deletion allele significantly increased coronary artery calcification in men with minimal coronary stenosis. Thus, not only does the rs3045215 deletion allele predict atherosclerosis, but it also predisposes to early-onset calcification in men.
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Affiliation(s)
- Ragnar O Vilmundarson
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada.,Laboratory of Translational Genomics, John and Jennifer Ruddy Canadian Cardiovascular Genetics Centre, University of Ottawa Heart Institute, Ottawa, ON, Canada
| | - An Duong
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada.,Laboratory of Translational Genomics, John and Jennifer Ruddy Canadian Cardiovascular Genetics Centre, University of Ottawa Heart Institute, Ottawa, ON, Canada
| | - Fariborz Soheili
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada.,Laboratory of Translational Genomics, John and Jennifer Ruddy Canadian Cardiovascular Genetics Centre, University of Ottawa Heart Institute, Ottawa, ON, Canada
| | - Hsiao-Huei Chen
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada.,The Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Alexandre F R Stewart
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada.,Laboratory of Translational Genomics, John and Jennifer Ruddy Canadian Cardiovascular Genetics Centre, University of Ottawa Heart Institute, Ottawa, ON, Canada
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23
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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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24
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Understanding the Stony Bridge between Osteoporosis and Vascular Calcification: Impact of the FGF23/Klotho axis. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:7536614. [PMID: 34539972 PMCID: PMC8448600 DOI: 10.1155/2021/7536614] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Accepted: 08/07/2021] [Indexed: 12/11/2022]
Abstract
A relationship between osteoporosis (OP) and vascular calcification (VC) is now proposed. There are common mechanisms underlying the regulation of them. Fibroblast growth factor- (FGF-) 23 and Klotho are hormones associated with the metabolic axis of osteovascular metabolism. Most recently, it was suggested that the FGF23-klotho axis is associated with increasing incidence of fractures and is potentially involved in the progression of the aortic-brachial stiffness ratio. Herein, we discussed the potential role of the FGF23/Klotho axis in the pathophysiology of OP and VC. We want to provide an update review in order to allow a better understanding of the potential role of the FGF23/Klotho axis in comorbidity of OP and VC. We believe that a better understanding of the relationship between both entities can help in proposing new therapeutic targets for reducing the increasing prevalence of OP and VC in the aging population.
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25
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Cheng Z, O'Brien K, Howe J, Sullivan C, Schrier D, Lynch A, Jungles S, Sabbagh Y, Thompson D. INZ-701 Prevents Ectopic Tissue Calcification and Restores Bone Architecture and Growth in ENPP1-Deficient Mice. J Bone Miner Res 2021; 36:1594-1604. [PMID: 33900645 DOI: 10.1002/jbmr.4315] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Revised: 04/08/2021] [Accepted: 04/17/2021] [Indexed: 12/20/2022]
Abstract
Ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) is the major enzyme that cleaves extracellular adenosine triphosphate (ATP) to generate pyrophosphate (PPi), an inorganic metabolite with potent anticalcification activity. Loss-of-function mutations cause hypopyrophosphatemia and lead to a state of ENPP1 deficiency, which has an acute infantile phase known as generalized arterial calcification of infancy (GACI) and a pediatric to adult phase known as autosomal-recessive hypophosphatemic rickets type 2 (ARHR2). ENPP1 deficiency manifests as ectopic calcification of multiple tissues, neointimal proliferation, premature mortality, impaired growth, and bone deformities. INZ-701, a human ENPP1-Fc protein, is in clinical development as an enzyme replacement therapy for the treatment of ENPP1 deficiency. The pharmacokinetic and pharmacodynamic profile and therapeutic effect of INZ-701 were investigated in Enpp1asj/asj mice, a murine model of ENPP1 deficiency. Enpp1asj/asj mice have undetectable plasma PPi, lower plasma phosphate, and higher FGF23 levels compared with wild-type (WT) mice. Enpp1asj/asj mice on the acceleration diet, containing high phosphate and low magnesium, quickly develop clinical signs, including dehydration, rough hair coat, pinned ears, stiffed legs, and hunched back. Enpp1asj/asj mice treated with vehicle had aforementioned clinical signs plus severe ectopic calcification in multiple tissues and bone defects, characteristics of the clinical phenotype observed in GACI and ARHR2 patients. Our results showed a durable PPi response for more than 3 days after a single dose of INZ-701. Treatment of ENPP1-deficient mice every other day with INZ-701 for 8 weeks restored circulating levels of PPi, prevented pathological calcification in all the tested organs, restored growth parameters, corrected bone defects, improved clinical signs, and decreased mortality in Enpp1asj/asj mice, demonstrating the potential of INZ-701 to treat ENPP1 deficiency. © 2021 American Society for Bone and Mineral Research (ASBMR).
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26
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Bulfamante GP, Carpenito L, Bragantini E, Graziani S, Bellizzi M, Bagowski CP, Shoukier M, Rivieri F, Soffiati M, Barbareschi M. Generalized Arterial Calcification of Infancy Type 1 (GACI1): Identification of a Novel Pathogenic Variant (c.1715T>C (p.Leu572Ser)). Diagnostics (Basel) 2021; 11:diagnostics11061034. [PMID: 34199854 PMCID: PMC8229691 DOI: 10.3390/diagnostics11061034] [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: 02/24/2021] [Revised: 05/29/2021] [Accepted: 05/30/2021] [Indexed: 11/16/2022] Open
Abstract
Generalized Arterial Calcification of Infancy (GACI) is a rare disease inherited in a recessive manner, with severe and diffuse early onset of calcifications along the internal elastic lamina in large and medium size arteries. The diagnosis results are from clinical manifestations, imaging, histopathologic exams, and genetic tests. GACI is predominantly caused by biallelic pathogenic variant in the ENPP1 gene (GACI1, OMIM#208000) and, to a lesser extent, by pathogenic variants in the ABCC6 gene (GACI2, OMIM#614473). We present a novel variation in the ENPP1 gene identified in a patient clinically diagnosed with GACI and confirmed by genetic investigation and autopsy as GACI type 1. The sequence analysis of the patient's ENPP1 gene detected two heterozygous variants c.1412A>G (p.Tyr471Cys) and c.1715T>C (p.Leu572Ser). The variant c.1715T>C (p.Leu572Ser) has not been described yet in the literature and in mutation databases. A genetic analysis was also carried out for the parents of the newborn; the heterozygous pathogenic variant c.1412A>G (p.Tyr471Cys) was detected in the mother's ENPP1 gene, and a sequence analysis of the father's ENPP1 gene revealed the novel heterozygous variant c.1715T>C (p.Leu572Ser). Our results showed that the variant c.1715T>C (p.Leu572Ser) may have a pathogenic role in the development of GACI type1 (GACI1, OMIM#208000), at least when associated with the pathogenic c.1412A>G (p.Tyr471Cys) variant. The identification of novel mutations potentially enabled genotype/phenotype associations that will ultimately have an impact on clinical management and prognosis for the disease.
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Affiliation(s)
- Gaetano Pietro Bulfamante
- Human Pathology and Medical Genetic Unit, Department of Health Sciences, San Paolo Hospital, University of Milan, 20142 Milan, Italy;
| | - Laura Carpenito
- School of Pathology, University of Milan, 20122 Milan, Italy
- Correspondence:
| | - Emma Bragantini
- Department of Pathology, Santa Chiara Hospital, 38122 Trento, Italy; (E.B.); (M.B.)
| | | | - Maria Bellizzi
- Department of Pediatrics, Santa Chiara Hospital, 38122 Trento, Italy; (M.B.); (M.S.)
| | - Christoph Peter Bagowski
- Prenatal Medicine Münich, Department of Molecular Genetics, University Hospital, Aiblingerstr. 8, 80639 Münich, Germany; (C.P.B.); (M.S.)
| | - Moneef Shoukier
- Prenatal Medicine Münich, Department of Molecular Genetics, University Hospital, Aiblingerstr. 8, 80639 Münich, Germany; (C.P.B.); (M.S.)
| | - Francesca Rivieri
- Medical Genetic Service, Santa Chiara Hospital, 38122 Trento, Italy;
| | - Massimo Soffiati
- Department of Pediatrics, Santa Chiara Hospital, 38122 Trento, Italy; (M.B.); (M.S.)
| | - Mattia Barbareschi
- Department of Pathology, Santa Chiara Hospital, 38122 Trento, Italy; (E.B.); (M.B.)
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27
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Butscheidt S, Tsourdi E, Rolvien T, Delsmann A, Stürznickel J, Barvencik F, Jakob F, Hofbauer LC, Mundlos S, Kornak U, Seefried L, Oheim R. Relevant genetic variants are common in women with pregnancy and lactation-associated osteoporosis (PLO) and predispose to more severe clinical manifestations. Bone 2021; 147:115911. [PMID: 33716164 DOI: 10.1016/j.bone.2021.115911] [Citation(s) in RCA: 4] [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: 10/26/2020] [Revised: 01/19/2021] [Accepted: 03/08/2021] [Indexed: 12/17/2022]
Abstract
Pregnancy and lactation-associated osteoporosis (PLO) is a rare skeletal disorder characterized by early-onset osteoporosis typically manifestating with vertebral compression fractures or transient osteoporosis of the hip. We hypothesized that genetic variants may play a role in the development of PLO. This study aimed to analyze the presence of genetic variants and a potential association with the clinical presentation in PLO. 42 women with PLO were included from 2013 to 2019 in a multicenter study in Germany. All cases underwent comprehensive genetic analysis based on a custom-designed gene panel including genes relevant for skeletal disorders. The skeletal status was assessed using dual-energy X-ray absorptiometry (DXA). Subgroups were further analyzed by serum bone turnover markers (n = 31) and high-resolution peripheral computed tomography (HR-pQCT; n = 23). We detected relevant genetic variants in 21 women (50%), with LRP5, WNT1 and COL1A1/A2 being the most commonly involved genes. The mean number of vertebral compression fractures was 3.3 ± 3.4 per case with a significantly higher occurrence in the subgroup with genetic variants (4.8 ± 3.7 vs. 1.8 ± 2.3, p = 0.02). Among the total cohort, DXA Z-scores were significantly lower at the lumbar spine compared to the femoral neck (p = 0.002). HR-pQCT revealed a pronounced reduction of trabecular and cortical thickness, while trabecular number was within the reference range. Eighteen women (43%) received a bone-specific therapy (primarily teriparatide). Overall, a steep increase in bone mass (+37.7%) was observed after 3 years. In conclusion, pregnancy and lactation represent skeletal risk factors, which may unmask hereditary bone disorders leading to PLO. These cases were affected more severely. Nevertheless, a timely diagnosis and adequate treatment can ensure a substantial recovery potential even without specific therapy. Patients with genetically induced low bone turnover (e.g.; LRP5, WNT1) may especially benefit from osteo-anabolic medication.
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Affiliation(s)
- Sebastian Butscheidt
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Division of Orthopaedics, Department of Trauma and Orthopaedic Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Elena Tsourdi
- Department of Medicine III, Technische Universität Dresden Medical Center, Dresden, Germany; Center for Healthy Aging, Technische Universität Dresden Medical Center, Dresden, Germany
| | - Tim Rolvien
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Division of Orthopaedics, Department of Trauma and Orthopaedic Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Alena Delsmann
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Julian Stürznickel
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Florian Barvencik
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Franz Jakob
- Orthopedic Center for Musculoskeletal Research, Orthopedic Department, University of Würzburg, Germany
| | - Lorenz C Hofbauer
- Department of Medicine III, Technische Universität Dresden Medical Center, Dresden, Germany; Center for Healthy Aging, Technische Universität Dresden Medical Center, Dresden, Germany
| | - Stefan Mundlos
- Institute of Medical Genetics and Human Genetics, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Uwe Kornak
- Institute of Medical Genetics and Human Genetics, Charité Universitätsmedizin Berlin, Berlin, Germany; Institute of Human Genetics, Universitätsmedizin Göttingen, Göttingen, Germany
| | - Lothar Seefried
- Orthopedic Center for Musculoskeletal Research, Orthopedic Department, University of Würzburg, Germany
| | - Ralf Oheim
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
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28
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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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Kar P, Millo T, Saha S, Mahtab S, Agarwal S, Goswami R. Osteogenic Mechanisms of Basal Ganglia Calcification and its ex vivo Model in the Hypoparathyroid Milieu. Endocrinology 2021; 162:6128830. [PMID: 33539507 DOI: 10.1210/endocr/bqab024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Indexed: 01/10/2023]
Abstract
CONTEXT Basal-ganglia calcification (BGC) is common (70%) in patients with chronic hypoparathyroidism. Interestingly, cortical gray matter is spared from calcification. The mechanism of BGC, role of hyperphosphatemia, and modulation of osteogenic molecules by parathyroid hormone (PTH) in its pathogenesis is not clear. OBJECTIVE We assessed the expression of a large repertoire of molecules with proosteogenic or antiosteogenic effects, including neuroprogenitor cells in caudate, dentate, and cortical gray matter from normal autopsy tissues. The effect of high phosphate and PTH was assessed in an ex vivo model of BGC using striatum tissue culture of the Sprague-Dawley rat. METHODS The messenger RNA and protein expression of 39 molecules involved in multiple osteogenic pathways were assessed in 25 autopsy tissues using reverse-transcriptase polymerase chain reaction, Western blot, and immunofluorescence. The striatal culture was maintained in a hypoparathyroid milieu for 24 days with and without (a) high phosphate (10-mm β-glycerophosphate) and (b) PTH(1-34) (50 ng/mL Dulbecco's modified Eagle's medium-F12 media) for their effect on striatal calcification and osteogenic molecules. RESULTS Procalcification molecules (osteonectin, β-catenin, klotho, FZD4, NT5E, LRP5, WNT3A, collagen-1α, and SOX2-positive neuroprogenitor stem cells) had significantly higher expression in the caudate than gray matter. Caudate nuclei also had higher expression of antiosteogenic molecules (osteopontin, carbonic anhydrase-II [CA-II], MGP, sclerostin, ISG15, ENPP1, and USP18). In an ex vivo model, striatum culture showed an increased propensity for calcified nodules with mineral deposition similar to that of bone tissue on Fourier-transformed infrared spectroscopy, alizarin, and von Kossa stain. Mineralization in striatal culture was enhanced by high phosphate and decreased by exogenous PTH through increased expression of CA-II. CONCLUSION This study provides a conceptual advance on the molecular mechanisms of BGC and the possibility of PTH therapy to prevent this complication in a hypoparathyroid milieu.
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Affiliation(s)
- Parmita Kar
- Department of Endocrinology and Metabolism, All India Institute of Medical Sciences, New Delhi, Delhi, India
| | - Tabin Millo
- Department of Forensic Medicine and Toxicology, New Delhi, Delhi, India
| | - Soma Saha
- Department of Endocrinology and Metabolism, All India Institute of Medical Sciences, New Delhi, Delhi, India
| | - Samrina Mahtab
- Department of Endocrinology and Metabolism, All India Institute of Medical Sciences, New Delhi, Delhi, India
| | - Shipra Agarwal
- Department of Pathology, All India Institute of Medical Sciences, New Delhi, Delhi, India
| | - Ravinder Goswami
- Department of Endocrinology and Metabolism, All India Institute of Medical Sciences, New Delhi, Delhi, India
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Stürznickel J, Rolvien T, Delsmann A, Butscheidt S, Barvencik F, Mundlos S, Schinke T, Kornak U, Amling M, Oheim R. Clinical Phenotype and Relevance of LRP5 and LRP6 Variants in Patients With Early-Onset Osteoporosis (EOOP). J Bone Miner Res 2021; 36:271-282. [PMID: 33118644 DOI: 10.1002/jbmr.4197] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 10/08/2020] [Accepted: 10/13/2020] [Indexed: 02/06/2023]
Abstract
Reduced bone mineral density (BMD; ie, Z-score ≤-2.0) occurring at a young age (ie, premenopausal women and men <50 years) in the absence of secondary osteoporosis is considered early-onset osteoporosis (EOOP). Mutations affecting the WNT signaling pathway are of special interest because of their key role in bone mass regulation. Here, we analyzed the effects of relevant LRP5 and LRP6 variants on the clinical phenotype, bone turnover, BMD, and bone microarchitecture. After exclusion of secondary osteoporosis, EOOP patients (n = 372) were genotyped by gene panel sequencing, and segregation analysis of variants in LRP5/LRP6 was performed. The clinical assessment included the evaluation of bone turnover parameters, BMD by dual-energy X-ray absorptiometry, and microarchitecture via high-resolution peripheral quantitative computed tomography (HR-pQCT). In 50 individuals (31 EOOP index patients, 19 family members), relevant variants affecting LRP5 or LRP6 were detected (42 LRP5 and 8 LRP6 variants), including 10 novel variants. Seventeen variants were classified as disease causing, 14 were variants of unknown significance, and 19 were BMD-associated single-nucleotide polymorphisms (SNPs). One patient harbored compound heterozygous LRP5 mutations causing osteoporosis-pseudoglioma syndrome. Fractures were reported in 37 of 50 individuals, consisting of vertebral (18 of 50) and peripheral (29 of 50) fractures. Low bone formation was revealed in all individuals. A Z-score ≤-2.0 was detected in 31 of 50 individuals, and values at the spine were significantly lower than those at the hip (-2.1 ± 1.3 versus -1.6 ± 0.8; p = .003). HR-pQCT analysis (n = 34) showed impaired microarchitecture in trabecular and cortical compartments. Significant differences regarding the clinical phenotype were detectable between index patients and family members but not between different variant classes. Relevant variants in LRP5 and LRP6 contribute to EOOP in a substantial number of individuals, leading to a high number of fractures, low bone formation, reduced Z-scores, and impaired microarchitecture. This detailed skeletal characterization improves the interpretation of known and novel LRP5 and LRP6 variants. © 2020 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Julian Stürznickel
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Tim Rolvien
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Department of Orthopedics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Alena Delsmann
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Sebastian Butscheidt
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Department of Orthopedics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Florian Barvencik
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Stefan Mundlos
- Institute of Medical Genetics and Human Genetics, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Thorsten Schinke
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Uwe Kornak
- Institute of Medical Genetics and Human Genetics, Charité Universitätsmedizin Berlin, Berlin, Germany.,Institute of Human Genetics, University Medical Center Göttingen, Göttingen, Germany
| | - Michael Amling
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Ralf Oheim
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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31
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Laurent MR, De Schepper J, Trouet D, Godefroid N, Boros E, Heinrichs C, Bravenboer B, Velkeniers B, Lammens J, Harvengt P, Cavalier E, Kaux JF, Lombet J, De Waele K, Verroken C, van Hoeck K, Mortier GR, Levtchenko E, Vande Walle J. Consensus Recommendations for the Diagnosis and Management of X-Linked Hypophosphatemia in Belgium. Front Endocrinol (Lausanne) 2021; 12:641543. [PMID: 33815294 PMCID: PMC8018577 DOI: 10.3389/fendo.2021.641543] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 02/19/2021] [Indexed: 12/11/2022] Open
Abstract
X-linked hypophosphatemia (XLH) is the most common genetic form of hypophosphatemic rickets and osteomalacia. In this disease, mutations in the PHEX gene lead to elevated levels of the hormone fibroblast growth factor 23 (FGF23), resulting in renal phosphate wasting and impaired skeletal and dental mineralization. Recently, international guidelines for the diagnosis and treatment of this condition have been published. However, more specific recommendations are needed to provide guidance at the national level, considering resource availability and health economic aspects. A national multidisciplinary group of Belgian experts convened to discuss translation of international best available evidence into locally feasible consensus recommendations. Patients with XLH may present to a wide array of primary, secondary and tertiary care physicians, among whom awareness of the disease should be raised. XLH has a very broad differential-diagnosis for which clinical features, biochemical and genetic testing in centers of expertise are recommended. Optimal care requires a multidisciplinary approach, guided by an expert in metabolic bone diseases and involving (according to the individual patient's needs) pediatric and adult medical specialties and paramedical caregivers, including but not limited to general practitioners, dentists, radiologists and orthopedic surgeons. In children with severe or refractory symptoms, FGF23 inhibition using burosumab may provide superior outcomes compared to conventional medical therapy with phosphate supplements and active vitamin D analogues. Burosumab has also demonstrated promising results in adults on certain clinical outcomes such as pseudofractures. In summary, this work outlines recommendations for clinicians and policymakers, with a vision for improving the diagnostic and therapeutic landscape for XLH patients in Belgium.
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Affiliation(s)
- Michaël R. Laurent
- Centre for Metabolic Bone Diseases, University Hospitals Leuven, Leuven, Belgium
- *Correspondence: Michaël R. Laurent,
| | - Jean De Schepper
- Division of Pediatric Endocrinology, KidZ Health Castle, University Hospital Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium
- Department of Pediatric Endocrinology, University Hospital Ghent, Ghent, Belgium
| | - Dominique Trouet
- Department of Pediatric Nephrology, Antwerp University Hospital, Antwerp, Belgium
- Laboratory of Experimental Medicine and Pediatrics, University of Antwerp, Antwerp, Belgium
| | - Nathalie Godefroid
- Pediatric Nephrology, Cliniques Universitaires St. Luc (UCL), Brussels, Belgium
| | - Emese Boros
- Paediatric Endocrinology Unit, Hôpital Universitaire des Enfants Reine Fabiola, Université Libre de Bruxelles, Brussels, Belgium
| | - Claudine Heinrichs
- Paediatric Endocrinology Unit, Hôpital Universitaire des Enfants Reine Fabiola, Université Libre de Bruxelles, Brussels, Belgium
| | - Bert Bravenboer
- Department of Endocrinology, University Hospital Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Brigitte Velkeniers
- Department of Endocrinology, University Hospital Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Johan Lammens
- Department of Orthopaedic Surgery and Department of Development and Regeneration, Prometheus LRD Division of Skeletal Tissue Engineering, KU Leuven - University Hospitals Leuven, Leuven, Belgium
| | - Pol Harvengt
- XLH Belgium, Belgian X-Linked Hypophosphatemic Rickets (XLH) Patient Association, Waterloo, Belgium
| | - Etienne Cavalier
- Department of Clinical Chemistry, University Hospital Center of Liège, University of Liège, Liège, Belgium
| | - Jean-François Kaux
- Physical Medicine, Rehabilitation and Sports Traumatology, University and University Hospital of Liège, Liège, Belgium
| | - Jacques Lombet
- Division of Nephrology, Department of Pediatrics, University Hospital Center of Liège, Liège, Belgium
| | - Kathleen De Waele
- Department of Pediatric Endocrinology, University Hospital Ghent, Ghent, Belgium
| | - Charlotte Verroken
- Unit for Osteoporosis and Metabolic Bone Diseases, Department of Endocrinology and Metabolism, Ghent University Hospital, Ghent, Belgium
| | - Koenraad van Hoeck
- Department of Pediatric Nephrology, Antwerp University Hospital, Antwerp, Belgium
- Laboratory of Experimental Medicine and Pediatrics, University of Antwerp, Antwerp, Belgium
| | - Geert R. Mortier
- Department of Medical Genetics, Antwerp University Hospital and University of Antwerp, Antwerp, Belgium
| | - Elena Levtchenko
- Department of Pediatrics/Pediatric Nephrology, University Hospitals Leuven, Leuven, Belgium
| | - Johan Vande Walle
- Department of Pediatric Nephrology, University Hospital Ghent, Ghent, Belgium
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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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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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Role of Metabolism in Bone Development and Homeostasis. Int J Mol Sci 2020; 21:ijms21238992. [PMID: 33256181 PMCID: PMC7729585 DOI: 10.3390/ijms21238992] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 11/22/2020] [Accepted: 11/25/2020] [Indexed: 02/07/2023] Open
Abstract
Carbohydrates, fats, and proteins are the underlying energy sources for animals and are catabolized through specific biochemical cascades involving numerous enzymes. The catabolites and metabolites in these metabolic pathways are crucial for many cellular functions; therefore, an imbalance and/or dysregulation of these pathways causes cellular dysfunction, resulting in various metabolic diseases. Bone, a highly mineralized organ that serves as a skeleton of the body, undergoes continuous active turnover, which is required for the maintenance of healthy bony components through the deposition and resorption of bone matrix and minerals. This highly coordinated event is regulated throughout life by bone cells such as osteoblasts, osteoclasts, and osteocytes, and requires synchronized activities from different metabolic pathways. Here, we aim to provide a comprehensive review of the cellular metabolism involved in bone development and homeostasis, as revealed by mouse genetic studies.
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Stabach PR, Zimmerman K, Adame A, Kavanagh D, Saeui CT, Agatemor C, Gray S, Cao W, De La Cruz EM, Yarema KJ, Braddock DT. Improving the Pharmacodynamics and In Vivo Activity of ENPP1-Fc Through Protein and Glycosylation Engineering. Clin Transl Sci 2020; 14:362-372. [PMID: 33064927 PMCID: PMC7877847 DOI: 10.1111/cts.12887] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 08/24/2020] [Indexed: 02/06/2023] Open
Abstract
Enzyme replacement with ectonucleotide pyrophosphatase phospodiesterase‐1 (ENPP1) eliminates mortality in a murine model of the lethal calcification disorder generalized arterial calcification of infancy. We used protein engineering, glycan optimization, and a novel biomanufacturing platform to enhance potency by using a three‐prong strategy. First, we added new N‐glycans to ENPP1; second, we optimized pH‐dependent cellular recycling by protein engineering of the Fc neonatal receptor; finally, we used a two‐step process to improve sialylation by first producing ENPP1‐Fc in cells stably transfected with human α‐2,6‐sialyltransferase (ST6) and further enhanced terminal sialylation by supplementing production with 1,3,4‐O‐Bu3ManNAc. These steps sequentially increased the half‐life of the parent compound in rodents from 37 hours to ~ 67 hours with an added N‐glycan, to ~ 96 hours with optimized pH‐dependent Fc recycling, to ~ 204 hours when the therapeutic was produced in ST6‐overexpressing cells with 1,3,4‐O‐Bu3ManNAc supplementation. The alterations were demonstrated to increase drug potency by maintaining efficacious levels of plasma phosphoanhydride pyrophosphate in ENPP1‐deficient mice when the optimized biologic was administered at a 10‐fold lower mass dose less frequently than the parent compound—once every 10 days vs. 3 times a week. We believe these improvements represent a general strategy to rationally optimize protein therapeutics.
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Affiliation(s)
- Paul R Stabach
- Department of Pathology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Kristin Zimmerman
- Department of Pathology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Aaron Adame
- Department of Pathology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Dillon Kavanagh
- Department of Pathology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Christopher T Saeui
- Department of Biomedical Engineering, Translational Tissue Engineering Center, The Johns Hopkins University, Baltimore, Maryland, USA
| | - Christian Agatemor
- Department of Biomedical Engineering, Translational Tissue Engineering Center, The Johns Hopkins University, Baltimore, Maryland, USA
| | - Shawn Gray
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
| | - Wenxiang Cao
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
| | - Enrique M De La Cruz
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
| | - Kevin J Yarema
- Department of Biomedical Engineering, Translational Tissue Engineering Center, The Johns Hopkins University, Baltimore, Maryland, USA
| | - Demetrios T Braddock
- Department of Pathology, Yale University School of Medicine, New Haven, Connecticut, USA
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Calcinosis in Systemic Sclerosis: Updates in Pathophysiology, Evaluation, and Treatment. Curr Rheumatol Rep 2020; 22:73. [DOI: 10.1007/s11926-020-00951-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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