1
|
Mandalapu A, Stevens KJ. Imaging findings of arterial calcification due to deficiency of CD73: A case study. J Radiol Case Rep 2023; 17:1-7. [PMID: 38828028 PMCID: PMC11075852 DOI: 10.3941/jrcr.v17i12.5175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2024] Open
Abstract
A 52-year-old male developed right knee pain after hiking in Guatemala. On his return he underwent a knee MRI for an indication of medial knee pain, which demonstrated a medial meniscal tear. However, the MRI demonstrated marked tortuosity and dense calcification of the popliteal artery, confirmed on subsequent radiographs. Review of previous CT studies of the abdomen and lower extremities showed severe ectasia and arterial calcification in the femoral and popliteal arteries bilaterally, but no calcifications in the aorta and common iliac arteries. Dual energy CT studies of the extremities demonstrated extensive periarticular soft tissue calcification throughout the wrists, hands, ankle and feet without evidence of uric acid. Review of the electronic medical records revealed a diagnosis of Arterial Calcification due to Deficiency of CD73 (ACDC), a rare genetic disorder presenting with debilitating pain in the wrists and hands, claudication of the calves, thighs and buttocks, progressing to chronic ischemia of the feet which may be limb-threatening. The patient was enrolled in an NIH trial of bisphosphonates and dual-antiplatelet therapy with stabilization of symptoms. This case discusses the imaging findings of this rare condition, differential diagnosis to consider, and current management.
Collapse
Affiliation(s)
- Aniruddh Mandalapu
- Department of Radiology, University of Rochester School of Medicine, Rochester, USA
| | - Kathryn J Stevens
- Department of Radiology, Stanford University School of Medicine, Palo Alto, USA
| |
Collapse
|
2
|
Murcia Casas B, Carrillo Linares JL, Baquero Aranda I, Rioja Villodres J, Merino Bohórquez V, González Jiménez A, Rico Corral MÁ, Bosch R, Sánchez Chaparro MÁ, García Fernández M, Valdivielso P. Lansoprazole Increases Inorganic Pyrophosphate in Patients with Pseudoxanthoma Elasticum: A Double-Blind, Randomized, Placebo-Controlled Crossover Trial. Int J Mol Sci 2023; 24:ijms24054899. [PMID: 36902331 PMCID: PMC10003519 DOI: 10.3390/ijms24054899] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 02/26/2023] [Accepted: 02/28/2023] [Indexed: 03/06/2023] Open
Abstract
Pseudoxanthoma elasticum (PXE) is characterized by low levels of inorganic pyrophosphate (PPi) and a high activity of tissue-nonspecific alkaline phosphatase (TNAP). Lansoprazole is a partial inhibitor of TNAP. The aim was to investigate whether lansoprazole increases plasma PPi levels in subjects with PXE. We conducted a 2 × 2 randomized, double-blind, placebo-controlled crossover trial in patients with PXE. Patients were allocated 30 mg/day of lansoprazole or a placebo in two sequences of 8 weeks. The primary outcome was the differences in plasma PPi levels between the placebo and lansoprazole phases. 29 patients were included in the study. There were eight drop-outs due to the pandemic lockdown after the first visit and one due to gastric intolerance, so twenty patients completed the trial. A generalized linear mixed model was used to evaluate the effect of lansoprazole. Overall, lansoprazole increased plasma PPi levels from 0.34 ± 0.10 µM to 0.41 ± 0.16 µM (p = 0.0302), with no statistically significant changes in TNAP activity. There were no important adverse events. 30 mg/day of lansoprazole was able to significantly increase plasma PPi in patients with PXE; despite this, the study should be replicated with a large number of participants in a multicenter trial, with a clinical end point as the primary outcome.
Collapse
Affiliation(s)
- Belén Murcia Casas
- Internal Medicine Unit, Hospital Universitario Virgen de la Victoria, 29010 Málaga, Spain
| | - Juan Luis Carrillo Linares
- Internal Medicine Unit, Hospital Universitario Virgen de la Victoria, 29010 Málaga, Spain
- Instituto de Investigación Biomédica de Málaga (IBIMA), 29010 Málaga, Spain
| | - Isabel Baquero Aranda
- Ophtalmology Unit, Hospital Universitario Virgen de la Victoria, 29010 Málaga, Spain
| | - José Rioja Villodres
- Instituto de Investigación Biomédica de Málaga (IBIMA), 29010 Málaga, Spain
- Centro de Investigaciones Médico-Sanitarias (CIMES), Universidad de Málaga, 29071 Málaga, Spain
| | | | | | | | - Ricardo Bosch
- Dermatology Unit, Hospital Universitario Virgen de la Victoria, 29010 Málaga, Spain
| | - Miguel Ángel Sánchez Chaparro
- Internal Medicine Unit, Hospital Universitario Virgen de la Victoria, 29010 Málaga, Spain
- Instituto de Investigación Biomédica de Málaga (IBIMA), 29010 Málaga, Spain
- Department of Medicine and Dermatology, University of Málaga, 29016 Málaga, Spain
| | - María García Fernández
- Instituto de Investigación Biomédica de Málaga (IBIMA), 29010 Málaga, Spain
- Department of Phisiology, Universidad de Málaga, 29016 Málaga, Spain
| | - Pedro Valdivielso
- Internal Medicine Unit, Hospital Universitario Virgen de la Victoria, 29010 Málaga, Spain
- Instituto de Investigación Biomédica de Málaga (IBIMA), 29010 Málaga, Spain
- Centro de Investigaciones Médico-Sanitarias (CIMES), Universidad de Málaga, 29071 Málaga, Spain
- Department of Medicine and Dermatology, University of Málaga, 29016 Málaga, Spain
- Correspondence: ; Tel.: +34-952131615
| |
Collapse
|
3
|
Ramirez-Suarez KI, Cohen SA, Barrera CA, Levine MA, Goldberg DJ, Otero HJ. Longitudinal assessment of vascular calcification in generalized arterial calcification of infancy. Pediatr Radiol 2022; 52:2329-2341. [PMID: 35438330 PMCID: PMC10406615 DOI: 10.1007/s00247-022-05364-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 02/18/2022] [Accepted: 03/18/2022] [Indexed: 10/18/2022]
Abstract
BACKGROUND Generalized arterial calcification of infancy (GACI), also known as idiopathic infantile arterial calcification, is a very uncommon genetic disorder characterized by calcifications and stenoses of large- and medium-size arteries that can lead to end-organ damage. OBJECTIVE To describe changes in imaging findings in 10 children with GACI at a single institution from 2010 to 2021. MATERIALS AND METHODS In this retrospective study we reviewed initial and follow-up body imaging in children with genetic confirmation of GACI at our hospital. All initial images were analyzed for the presence and distribution of arterial calcifications, stenoses and wall thickening/irregularity within the chest, abdomen and pelvis. We compared available follow-up studies to the initial imaging findings. We extracted clinical information including prenatal and postnatal treatment from the children's medical records. RESULTS We evaluated 10 children (five boys) with a diagnosis of GACI. Median age at first body imaging was 8 days (range: 1 day to 5 years). Six children were identified prenatally and four postnatally. Postnatal presentation included cardiac failure, seizures and hypertension. Images in newborns (n = 8) most commonly showed diffuse arterial calcifications (6/8; 75%), while stenoses were less common (2/8; 25%) during this period. Two children were diagnosed after the neonatal period - one in infancy and one during childhood. In total, half the children (5/10; 50%) had arterial stenoses - three cases visualized at first imaging and two identified on follow-up images during infancy. Stenoses had completely resolved in one child (1/5; 20%) at last follow-up. Eight children received prenatal or postnatal treatment or both. All children who received both prenatal and postnatal treatment (n = 4) had completely resolved calcifications at last follow-up. CONCLUSION Children with GACI might have characteristic vascular calcifications at birth that raise the suspicion of this disease. Arterial calcifications decrease or disappear spontaneously or after treatment, but arterial stenoses usually persist. Calcifications and arterial stenoses can be easily identified and followed with non-contrast CT and CT angiography.
Collapse
Affiliation(s)
- Karen I Ramirez-Suarez
- Department of Radiology, Children's Hospital of Philadelphia, 3401 Civic Center Blvd., Philadelphia, PA, 19104, USA
| | - Sara A Cohen
- Department of Radiology at Weill Cornell Medicine, New York, NY, USA
| | - Christian A Barrera
- Department of Radiology, Children's Hospital of Philadelphia, 3401 Civic Center Blvd., Philadelphia, PA, 19104, USA
| | - Michael A Levine
- Division of Endocrinology and Diabetes, Center for Bone Health, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
- Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - David J Goldberg
- Division of Cardiology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Hansel J Otero
- Department of Radiology, Children's Hospital of Philadelphia, 3401 Civic Center Blvd., Philadelphia, PA, 19104, USA.
- Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA.
| |
Collapse
|
4
|
Hsu VM, Kozák E, Li Q, Bocskai M, Schlesinger N, Rosenthal A, McClure ST, Kovács L, Bálint L, Szamosi S, Szücs G, Carns M, Aren K, Goldberg I, Váradi A, Varga J. Inorganic pyrophosphate is reduced in patients with systemic sclerosis. Rheumatology (Oxford) 2022; 61:1158-1165. [PMID: 34152415 PMCID: PMC9052889 DOI: 10.1093/rheumatology/keab508] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 06/12/2021] [Indexed: 01/07/2023] Open
Abstract
OBJECTIVE The pathogenesis of calcinosis cutis, a disabling complication of SSc, is poorly understood and effective treatments are lacking. Inorganic pyrophosphate (PPi) is a key regulator of ectopic mineralization, and its deficiency has been implicated in ectopic mineralization disorders. We therefore sought to test the hypothesis that SSc may be associated with reduced circulating PPi, which might play a pathogenic role in calcinosis cutis. METHODS Subjects with SSc and age-matched controls without SSc were recruited from the outpatient rheumatology clinics at Rutgers and Northwestern Universities (US cohort), and from the Universities of Szeged and Debrecen (Hungarian cohort). Calcinosis cutis was confirmed by direct palpation, by imaging or both. Plasma PPi levels were determined in platelet-free plasma using ATP sulfurylase to convert PPi into ATP in the presence of excess adenosine 5' phosphosulfate. RESULTS Eighty-one patients with SSc (40 diffuse cutaneous, and 41 limited cutaneous SSc) in the US cohort and 45 patients with SSc (19 diffuse cutaneous and 26 limited cutaneous SSc) in the Hungarian cohort were enrolled. Calcinosis was frequently detected (40% of US and 46% of the Hungarian cohort). Plasma PPi levels were significantly reduced in both SSc cohorts with and without calcinosis (US: P = 0.003; Hungarian: P < 0.001). CONCLUSIONS Circulating PPi are significantly reduced in SSc patients with or without calcinosis. Reduced PPi may be important in the pathophysiology of calcinosis and contribute to tissue damage with chronic SSc. Administering PPi may be a therapeutic strategy and larger clinical studies are planned to confirm our findings.
Collapse
Affiliation(s)
- Vivien M Hsu
- Rheumatology Division, Department of Medicine, Rutgers-RWJ Medical School, New Brunswick, NJ, USA
| | - Eszter Kozák
- Institute of Enzymology, Research Center for Natural Sciences, Hungarian Academy of Sciences Centre of Excellence, Budapest, Hungary
| | - Qiaoli Li
- The Sidney Kimmel Medical College, The PXE International Center of Excellence in Research and Clinical Care, and Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, PA, USA
| | - Márta Bocskai
- Department of Rheumatology and Immunology, University of Szeged, Szeged, Hungary
| | - Naomi Schlesinger
- Rheumatology Division, Department of Medicine, Rutgers-RWJ Medical School, New Brunswick, NJ, USA
| | - Ann Rosenthal
- Rheumatology Division, Department of Medicine, Medical College of Wisconsin, Milwaukee, WI
| | - Scott T McClure
- Department of Statistics, Shenandoah University, Winchester, VA
- Rebel Analytics, LLC, Laguna Hills, CA, USA
| | - László Kovács
- Department of Rheumatology and Immunology, University of Szeged, Szeged, Hungary
| | - László Bálint
- Genomic Medicine and Bioinformatic Core Facility, Department of Biochemistry and Molecular Biology, University of Debrecen, Hungary University of Szeged, Szeged
| | - Szilvia Szamosi
- Division of Rheumatology, University of Debrecen, Debrecen, Hungary
| | - Gabriella Szücs
- Division of Rheumatology, University of Debrecen, Debrecen, Hungary
| | - Mary Carns
- Divisions of Rheumatology and Pulmonary and Critical Care Medicine, Department of Medicine, Northwestern University, Chicago, IL
| | - Kathleen Aren
- Divisions of Rheumatology and Pulmonary and Critical Care Medicine, Department of Medicine, Northwestern University, Chicago, IL
| | - Isaac Goldberg
- Divisions of Rheumatology and Pulmonary and Critical Care Medicine, Department of Medicine, Northwestern University, Chicago, IL
| | - András Váradi
- Institute of Enzymology, Research Center for Natural Sciences, Hungarian Academy of Sciences Centre of Excellence, Budapest, Hungary
| | - John Varga
- Divisions of Rheumatology and Pulmonary and Critical Care Medicine, Department of Medicine, Northwestern University, Chicago, IL
- Rheumatology Division, Department of Medicine, University of Michigan, Ann Arbor, MI, USA
| |
Collapse
|
5
|
Boraldi F, Murro V, Lofaro FD, Mucciolo DP, Costa S, Pavese L, Quaglino D. Phenotypic Features and Genetic Findings in a Cohort of Italian Pseudoxanthoma Elasticum Patients and Update of the Ophthalmologic Evaluation Score. J Clin Med 2021; 10:2710. [PMID: 34205333 PMCID: PMC8235548 DOI: 10.3390/jcm10122710] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 06/11/2021] [Accepted: 06/16/2021] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Pseudoxanthoma elasticum (PXE) is a rare ectopic calcification genetic disease mainly caused by ABCC6 rare sequence variants. The clinical phenotype is characterized by typical dermatological, ophthalmological and cardiovascular manifestations, whose frequency and severity are differently reported in the literature. METHODS A retrospective study was performed on 377 PXE patients of Italian origin, clinically evaluated according to the Phenodex Index, who underwent ABCC6 biomolecular analyses. Moreover, 53 PXE patients were further characterized by in-depth ophthalmological examinations. RESULTS A total of 117 different ABCC6 rare sequence variants were detected as being spread through the whole gene. The severity of the clinical phenotype was dependent on age, but it was not influenced by gender or by the type of sequence variants. In-depth ophthalmological examinations focused on the incidences of coquille d'oeuf, comet lesions, pattern dystrophy-like lesions, optic disk drusen and posterior-pole atrophy. Conclusion: Given the large number of patients analyzed, we were able to better evaluate the occurrence of less frequent alterations (e.g., stroke, myocardial infarction, nephrolithiasis). A more detailed description of ophthalmological abnormalities allowed us to stratify patients and better evaluate disease progression, thus suggesting a further update of the PXE score system.
Collapse
Affiliation(s)
- Federica Boraldi
- Department of Life Science, University of Modena and Reggio Emilia, Via Campi 287, 41125 Modena, Italy; (F.B.); (F.D.L.); (S.C.)
| | - Vittoria Murro
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Eye Clinic, Viale Pieraccini 6, 50139 Florence, Italy; (V.M.); (D.P.M.); (L.P.)
| | - Francesco Demetrio Lofaro
- Department of Life Science, University of Modena and Reggio Emilia, Via Campi 287, 41125 Modena, Italy; (F.B.); (F.D.L.); (S.C.)
| | - Dario Pasquale Mucciolo
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Eye Clinic, Viale Pieraccini 6, 50139 Florence, Italy; (V.M.); (D.P.M.); (L.P.)
| | - Sonia Costa
- Department of Life Science, University of Modena and Reggio Emilia, Via Campi 287, 41125 Modena, Italy; (F.B.); (F.D.L.); (S.C.)
| | - Laura Pavese
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Eye Clinic, Viale Pieraccini 6, 50139 Florence, Italy; (V.M.); (D.P.M.); (L.P.)
| | - Daniela Quaglino
- Department of Life Science, University of Modena and Reggio Emilia, Via Campi 287, 41125 Modena, Italy; (F.B.); (F.D.L.); (S.C.)
| |
Collapse
|
6
|
Murro V, Mucciolo DP, Giorgio D, Pavese L, Boraldi F, Quaglino D, Finocchio L, Sodi A, Virgili G, Giansanti F. Adaptive Optics Imaging in Patients Affected by Pseudoxanthoma Elasticum. Am J Ophthalmol 2021; 224:84-95. [PMID: 33316262 DOI: 10.1016/j.ajo.2020.12.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 12/03/2020] [Accepted: 12/04/2020] [Indexed: 12/31/2022]
Abstract
PURPOSE To describe the retinal findings of patients affected by pseudoxanthoma elasticum (PXE) using a multimodal imaging approach including flood-illumination adaptive optics ophthalmoscopy (AO). DESIGN Retrospective case series. MATERIALS AND METHODS Patients affected by PXE were retrospectively studied. Clinical data, color, infrared and autofluorescence fundus imaging, optical coherence tomographic scans, and AO examinations were collected. Furthermore, the photoreceptor count was assessed. PXE diagnosis was confirmed by a positive skin biopsy and/or genetic testing. RESULTS Twenty-one eyes of 18 patients (11 females and 7 males) were included in the study. In 3 patients, both eyes were studied. The mean age at examination was 37.7 ± 16.4 years (range 14-66) and the mean best-corrected visual acuity (BCVA) was 0.1 ± 0.2 logMAR (range 0-1). We identified 3 types of angioid streaks (AS) using AO: "crack," "band," and "hypopigmented." The first 2 were very similar and they differed in size; the third type showed specific clinical features. Comet lesions appeared as hyper-reflective round lesions on AO imaging. In all eyes, the cone mosaic appeared reduced inside the streaks compared to the neighboring areas (13,532.8 ± 1,366.5 cones/mm2 vs 16,817.1 ± 1,263.0 cones/mm2 respectively). CONCLUSION Using AO imaging in PXE-related retinopathy, we were able to observe the presence of the photoreceptors within the angioid streaks, differentiate 3 types of angioid streaks, based on size and reflective features, and identify the very small crystalline bodies not identifiable using other retinal imaging techniques.
Collapse
|
7
|
Veiga-Lopez A, Sethuraman V, Navasiolava N, Makela B, Olomu I, Long R, van de Wetering K, Martin L, Aranyi T, Szeri F. Plasma Inorganic Pyrophosphate Deficiency Links Multiparity to Cardiovascular Disease Risk. Front Cell Dev Biol 2020; 8:573727. [PMID: 33363139 PMCID: PMC7755719 DOI: 10.3389/fcell.2020.573727] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 11/18/2020] [Indexed: 12/17/2022] Open
Abstract
Epidemiological studies indicate that elevated alkaline phosphatase activity is associated with increased cardiovascular disease risk. Other epidemiological data demonstrate that mothers giving multiple childbirths (multipara) are also at increased risk of developing late-onset cardiovascular disease. We hypothesized that these two associations stem from a common cause, the insufficient plasma level of the ectopic mineralization inhibitor inorganic pyrophosphate, which is a substrate of alkaline phosphatase. As alkaline phosphatase activity is elevated in pregnancy, we hypothesized that pyrophosphate concentrations decrease gestationally, potentially leading to increased maternal vascular calcification and cardiovascular disease risk in multipara. We investigated plasma pyrophosphate kinetics pre- and postpartum in sheep and at term in humans and demonstrated its shortage in pregnancy, mirroring alkaline phosphatase activity. Next, we tested whether multiparity is associated with increased vascular calcification in pseudoxanthoma elasticum patients, characterized by low intrinsic plasma pyrophosphate levels. We demonstrated that these patients had increased vascular calcification when they give birth multiple times. We propose that transient shortages of pyrophosphate during repeated pregnancies might contribute to vascular calcification and multiparity-associated cardiovascular disease risk threatening hundreds of millions of healthy women worldwide. Future trials are needed to assess if gestational pyrophosphate supplementation might be a suitable prophylactic treatment to mitigate maternal cardiovascular disease risk in multiparous women.
Collapse
Affiliation(s)
- Almudena Veiga-Lopez
- Department of Pathology, The University of Illinois at Chicago, Chicago, IL, United States.,Department of Animal Science, Michigan State University, East Lansing, MI, United States
| | - Visalakshi Sethuraman
- Department of Pediatrics and Human Development, Michigan State University, Lansing, MI, United States.,Department of Pediatrics, Texas Tech University Health Sciences Center, Odessa, TX, United States
| | | | - Barbara Makela
- Department of Animal Science, Michigan State University, East Lansing, MI, United States
| | - Isoken Olomu
- Department of Pediatrics and Human Development, Michigan State University, Lansing, MI, United States
| | - Robert Long
- Department of Obstetrics and Gynecology, Sparrow Hospital, Lansing, MI, United States
| | - Koen van de Wetering
- Department of Dermatology and Cutaneous Biology, PXE International Center of Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, PA, United States
| | - Ludovic Martin
- Department of Pediatrics, Texas Tech University Health Sciences Center, Odessa, TX, United States
| | - Tamas Aranyi
- Department of Molecular Biology, Semmelweis University, Budapest, Hungary.,Institute of Enzymology, Research Centre for Natural Sciences, Budapest, Hungary
| | - Flora Szeri
- Department of Dermatology and Cutaneous Biology, PXE International Center of Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, PA, United States.,Institute of Enzymology, Research Centre for Natural Sciences, Budapest, Hungary.,Department of Biochemistry, Semmelweis University, Budapest, Hungary
| |
Collapse
|
8
|
Rutsch F, Buers I, Nitschke Y. Hereditary Disorders of Cardiovascular Calcification. Arterioscler Thromb Vasc Biol 2020; 41:35-47. [PMID: 33176451 DOI: 10.1161/atvbaha.120.315577] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Arterial calcification is a common phenomenon in the elderly, in patients with atherosclerosis or renal failure and in diabetes. However, when present in very young individuals, it is likely to be associated with an underlying hereditary disorder of arterial calcification. Here, we present an overview of the few monogenic disorders presenting with early-onset cardiovascular calcification. These disorders can be classified according to the function of the respective disease gene into (1) disorders caused by an altered purine and phosphate/pyrophosphate metabolism, (2) interferonopathies, and (3) Gaucher disease. The finding of arterial calcification in early life should alert the clinician and prompt further genetic work-up to define the underlying genetic defect, to establish the correct diagnosis, and to enable appropriate therapy.
Collapse
Affiliation(s)
- Frank Rutsch
- Department of General Pediatrics, Muenster University Children's Hospital, Germany
| | - Insa Buers
- Department of General Pediatrics, Muenster University Children's Hospital, Germany
| | - Yvonne Nitschke
- Department of General Pediatrics, Muenster University Children's Hospital, Germany
| |
Collapse
|
9
|
Whyte MP, Zhang F, Wenkert D, Mumm S, Berndt TJ, Kumar R. Hyperphosphatemia with low FGF7 and normal FGF23 and sFRP4 levels in the circulation characterizes pediatric hypophosphatasia. Bone 2020; 134:115300. [PMID: 32112990 PMCID: PMC7233305 DOI: 10.1016/j.bone.2020.115300] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 02/20/2020] [Accepted: 02/21/2020] [Indexed: 12/18/2022]
Abstract
Hypophosphatasia (HPP) is the inborn-error-of-metabolism caused by loss-of-function mutation(s) of the ALPL gene that encodes the tissue-nonspecific isoenzyme of alkaline phosphatase (TNSALP). TNSALP in healthy individuals is on cell surfaces richly in bone, liver, and kidney. Thus, TNSALP natural substrates accumulate extracellularly in HPP, including inorganic pyrophosphate (PPi), a potent inhibitor of hydroxyapatite crystal formation and growth. Superabundance of extracellular PPi (ePPi) in HPP impairs mineralization of bones and teeth, often leading to rickets during childhood and osteomalacia in adult life and to tooth loss at any age. HPP's remarkably broad-ranging severity is largely explained by nearly four hundred typically missense mutations throughout the ALPL gene that are transmitted as an autosomal dominant or autosomal recessive trait. In the clinical laboratory, the biochemical hallmark of HPP is low serum ALP activity (hypophosphatasemia). However, our experience indicates that hyperphosphatemia from increased renal reclamation of filtered inorganic phosphate (Pi) is also common. Herein, from our prospective single-center study, we document throughout the clinical spectrum of non-lethal pediatric HPP that hyperphosphatemia reflects increased renal tubular threshold maximum for phosphorus adjusted for the glomerular filtration rate (TmP/GFR). To explore its pathogenesis, we studied mineral metabolism and quantitated circulating levels of three phosphatonins [fibroblast growth factor 23 (FGF23), secreted frizzled-related protein 4 (sFRP4), and fibroblast growth factor 7 (FGF7)] in 41 pediatric patients with HPP, 73 with X-linked hypophosphatemia (XLH), and 15 healthy pediatric control (CTR) subjects. The HPP and XLH cohorts had normal serum total and ionized calcium and parathyroid hormone levels (Ps > 0.10) and uncompromised glomerular filtration. In XLH, serum FGF23 was characteristically elevated (P < 0.0001) and despite hypophosphatemia sFRP4 was normal (P > 0.4) while FGF7 was low (P < 0.0001). In HPP, despite hyperphosphatemia serum FGF23 and sFRP4 were normal (Ps > 0.8) while FGF7 was low (P < 0.0001). Subsequently, in rats, we confirmed that FGF7 is phosphaturic. Thus, hyperphosphatemia in non-lethal pediatric HPP is associated with phosphatonin insufficiency together with, as we discuss, ePPi excess and diminished renal TNSALP activity.
Collapse
Affiliation(s)
- Michael P Whyte
- Center for Metabolic Bone Disease and Molecular Research, Shriners Hospitals for Children - St Louis, St. Louis, MO 63110, USA; Division of Bone and Mineral Diseases, Department of Internal Medicine, Washington University School of Medicine at Barnes-Jewish Hospital, St. Louis, MO 63110, USA.
| | - Fan Zhang
- Center for Metabolic Bone Disease and Molecular Research, Shriners Hospitals for Children - St Louis, St. Louis, MO 63110, USA.
| | - Deborah Wenkert
- Center for Metabolic Bone Disease and Molecular Research, Shriners Hospitals for Children - St Louis, St. Louis, MO 63110, USA.
| | - Steven Mumm
- Center for Metabolic Bone Disease and Molecular Research, Shriners Hospitals for Children - St Louis, St. Louis, MO 63110, USA; Division of Bone and Mineral Diseases, Department of Internal Medicine, Washington University School of Medicine at Barnes-Jewish Hospital, St. Louis, MO 63110, USA.
| | - Theresa J Berndt
- Division of Nephrology and Hypertension, Departments of Medicine and Biochemistry & Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
| | - Rajiv Kumar
- Division of Nephrology and Hypertension, Departments of Medicine and Biochemistry & Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN 55905, USA.
| |
Collapse
|
10
|
Quaglino D, Boraldi F, Lofaro FD. The biology of vascular calcification. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2020; 354:261-353. [PMID: 32475476 DOI: 10.1016/bs.ircmb.2020.02.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Vascular calcification (VC), characterized by different mineral deposits (i.e., carbonate apatite, whitlockite and hydroxyapatite) accumulating in blood vessels and valves, represents a relevant pathological process for the aging population and a life-threatening complication in acquired and in genetic diseases. Similarly to bone remodeling, VC is an actively regulated process in which many cells and molecules play a pivotal role. This review aims at: (i) describing the role of resident and circulating cells, of the extracellular environment and of positive and negative factors in driving the mineralization process; (ii) detailing the types of VC (i.e., intimal, medial and cardiac valve calcification); (iii) analyzing rare genetic diseases underlining the importance of altered pyrophosphate-dependent regulatory mechanisms; (iv) providing therapeutic options and perspectives.
Collapse
Affiliation(s)
- Daniela Quaglino
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy.
| | - Federica Boraldi
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | | |
Collapse
|
11
|
Dursun F, Atasoy Öztürk T, Güven S, Kırmızıbekmez H, Seymen Karabulut G, Kalın S, Sözeri B. Magnesium and Anti-phosphate Treatment with Bisphosphonates for Generalised Arterial Calcification of Infancy: A Case Report. J Clin Res Pediatr Endocrinol 2019; 11:311-318. [PMID: 30525344 PMCID: PMC6745454 DOI: 10.4274/jcrpe.galenos.2018.2018.0204] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Generalized arterial calcification of infancy (GACI) is a rare autosomal-recessive disorder, characterized by calcification of the internal elastic lamina, fibrotic myointimal proliferation of muscular arteries and resultant arterial stenosis. Treatment with bisphosphonates has been proposed as a means of reducing arterial calcifications in GACI patients, although there is no formalized treatment approach. The case reported here was a patient with severe GACI diagnosed at three months of age who had no response to bisphosphonate treatment, but clinically improved after the initiation of magnesium and anti-phosphate (using calcium carbonate) treatments. In patients unresponsive to bisphosphonate, magnesium and anti-phosphate treatment may be attempted.
Collapse
Affiliation(s)
- Fatma Dursun
- Ümraniye Training and Research Hospital, Clinic of Pediatric Endocrinology, İstanbul, Turkey,* Address for Correspondence: Ümraniye Training and Research Hospital, Department of Pediatric Endocrinology, İstanbul, Turkey Phone: +90 505 267 14 03 E-mail:
| | - Tülay Atasoy Öztürk
- Ümraniye Training and Research Hospital, Clinic of Radiology, İstanbul, Turkey
| | - Serçin Güven
- Ümraniye Training and Research Hospital, Clinic of Pediatric Nephrology, İstanbul, Turkey
| | - Heves Kırmızıbekmez
- Ümraniye Training and Research Hospital, Clinic of Pediatric Endocrinology, İstanbul, Turkey
| | - Gülcan Seymen Karabulut
- Ümraniye Training and Research Hospital, Clinic of Pediatric Endocrinology, İstanbul, Turkey
| | - Sevinç Kalın
- Ümraniye Training and Research Hospital, Clinic of Radiology, İstanbul, Turkey
| | - Betül Sözeri
- Ümraniye Training and Research Hospital, Clinic of Pediatric Rheumatology, İstanbul, Turkey
| |
Collapse
|
12
|
Nollet L, Van Gils M, Verschuere S, Vanakker O. The Role of Vitamin K and Its Related Compounds in Mendelian and Acquired Ectopic Mineralization Disorders. Int J Mol Sci 2019; 20:E2142. [PMID: 31052252 PMCID: PMC6540172 DOI: 10.3390/ijms20092142] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 04/24/2019] [Accepted: 04/24/2019] [Indexed: 12/11/2022] Open
Abstract
Ectopic mineralization disorders comprise a broad spectrum of inherited or acquired diseases characterized by aberrant deposition of calcium crystals in multiple organs, such as the skin, eyes, kidneys, and blood vessels. Although the precise mechanisms leading to ectopic calcification are still incompletely known to date, various molecular targets leading to a disturbed balance between pro- and anti-mineralizing pathways have been identified in recent years. Vitamin K and its related compounds, mainly those post-translationally activated by vitamin K-dependent carboxylation, may play an important role in the pathogenesis of ectopic mineralization as has been demonstrated in studies on rare Mendelian diseases, but also on highly prevalent disorders, like vascular calcification. This narrative review compiles and summarizes the current knowledge regarding the role of vitamin K, its metabolism, and associated compounds in the pathophysiology of both monogenic ectopic mineralization disorders, like pseudoxanthoma elasticum or Keutel syndrome, as well as acquired multifactorial diseases, like chronic kidney disease. Clinical and molecular aspects of the various disorders are discussed according to the state-of-the-art, followed by a comprehensive literature review regarding the role of vitamin K in molecular pathophysiology and as a therapeutic target in both human and animal models of ectopic mineralization disorders.
Collapse
Affiliation(s)
- Lukas Nollet
- Center for Medical Genetics, Ghent University Hospital, 9000 Ghent, Belgium.
| | - Matthias Van Gils
- Center for Medical Genetics, Ghent University Hospital, 9000 Ghent, Belgium.
- Department of Biomolecular Medicine, Ghent University, 9000 Ghent, Belgium.
| | - Shana Verschuere
- Center for Medical Genetics, Ghent University Hospital, 9000 Ghent, Belgium.
- Department of Biomolecular Medicine, Ghent University, 9000 Ghent, Belgium.
| | - Olivier Vanakker
- Center for Medical Genetics, Ghent University Hospital, 9000 Ghent, Belgium.
- Department of Biomolecular Medicine, Ghent University, 9000 Ghent, Belgium.
| |
Collapse
|
13
|
Li Q, Uitto J. Heritable Ectopic Mineralization Disorders: Pathomechanisms and Potential Treatment. J Investig Dermatol Symp Proc 2018; 19:S106-S107. [PMID: 30471751 DOI: 10.1016/j.jisp.2018.10.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Pseudoxanthoma elasticum (PXE), a prototype of heritable ectopic mineralization disorders, is an autosomal recessive disease characterized by deposition of calcium hydroxyapatite in the skin, eyes, and cardiovascular system, with protean manifestations (Li et al., 2016; Li and Uitto, 2013; Neldner, 1988). The classic form of PXE is late-onset and slow-progressing, and the major clinical problems relate to loss of vision and development of cardiovascular complications (Neldner, 1988). The classic form of PXE is caused by loss-of-function mutations in the ABCC6 gene encoding ATP-binding cassette subfamily C, member 6 (ABCC6), a putative transmembrane efflux transporter protein expressed primarily in the liver and kidneys. The metabolic hypothesis concerning PXE postulates that the absence of functional ABCC6 activity, primarily in the liver, results in deficiency of circulating factor(s) that is physiologically required to prevent ectopic mineralization under normal calcium and phosphate homeostasis (Li et al., 2016) (Figure 1). However, the factor(s) transported by ABCC6 from the intracellular milieu to the extracellular space have not been identified.
Collapse
Affiliation(s)
- Qiaoli Li
- Department of Dermatology and Cutaneous Biology, and Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania, USA.
| | - Jouni Uitto
- Department of Dermatology and Cutaneous Biology, and Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| |
Collapse
|
14
|
Salas-Alanis JC, Cepeda-Valdes R, Fortuna G, Li Q, Uitto J. Pseudoxanthoma elasticum: Dermoscopy and mutation analysis. Australas J Dermatol 2018; 60:e156-e158. [PMID: 30229859 DOI: 10.1111/ajd.12930] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Julio Cesar Salas-Alanis
- Dystrophic Epidermolysis Bullosa Research Association Mexico Foundation, Monterrey, Nuevo Leon, Mexico
| | - Rodrigo Cepeda-Valdes
- Dystrophic Epidermolysis Bullosa Research Association Mexico Foundation, Monterrey, Nuevo Leon, Mexico
| | - Giulio Fortuna
- Dystrophic Epidermolysis Bullosa Research Association Mexico Foundation, Monterrey, Nuevo Leon, Mexico.,Department of Neurosciences, Reproductive and Odontostomatological Sciences, Federico II University of Naples, Naples, Italy
| | - Qiaoli Li
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, and PXE International Center of Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Jouni Uitto
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, and PXE International Center of Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| |
Collapse
|
15
|
Li Q, Kingman J, Sundberg JP, Levine MA, Uitto J. Etidronate prevents, but does not reverse, ectopic mineralization in a mouse model of pseudoxanthoma elasticum ( Abcc6-/- ). Oncotarget 2018; 9:30721-30730. [PMID: 30112102 PMCID: PMC6089405 DOI: 10.18632/oncotarget.10738] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 06/09/2016] [Indexed: 12/13/2022] Open
Abstract
Pseudoxanthoma elasticum (PXE) and generalized arterial calcification of infancy (GACI) are heritable disorders manifesting with ectopic tissue mineralization. Most cases of PXE and some cases of GACI are caused by mutations in the ABCC6 gene, resulting in reduced plasma pyrophosphate (PPi) levels. There is no effective treatment for these disorders. It has been suggested that administration of bisphosphonates, stable and non-hydrolyzable PPi analogs, could counteract ectopic mineralization in these disorders. In this study we tested the potential efficacy of etidronate, a first generation bisphosphonate, on ectopic mineralization in the muzzle skin of Abcc6-/- mice, a model of PXE. The Abcc6-/- mice received subcutaneous injections of etidronate, 0.283 and 3.40 mg/kg per injection (0.01× and 0.12×), twice a week, in both prevention and reversal studies. Ectopic mineralization in the dermal sheath of vibrissae in muzzle skin was determined by histopathologic analysis and by direct chemical assay for calcium content. Subcutaneous injection of etidronate prevented ectopic mineralization but did not reverse existing mineralization. The effect of etidronate was accompanied by alterations in the trabecular bone microarchitecture, determined by micro-computed tomography. The results suggest that etidronate may offer a potential treatment modality for PXE and GACI caused by ABCC6 mutations. Etidronate therapy should be initiated in PXE patients as soon as the diagnosis is made, with careful monitoring of potential side effects.
Collapse
Affiliation(s)
- Qiaoli Li
- Department of Dermatology and Cutaneous Biology, The Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA, USA
| | - Joshua Kingman
- Department of Dermatology and Cutaneous Biology, The Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA, USA
| | | | - Michael A. Levine
- Division of Endocrinology and Diabetes, Children's Hospital of Philadelphia and University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Jouni Uitto
- Department of Dermatology and Cutaneous Biology, The Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA, USA
| |
Collapse
|
16
|
Elevated dietary magnesium during pregnancy and postnatal life prevents ectopic mineralization in Enpp1asj mice, a model for generalized arterial calcification of infancy. Oncotarget 2018; 8:38152-38160. [PMID: 28402956 PMCID: PMC5503522 DOI: 10.18632/oncotarget.16687] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 03/16/2017] [Indexed: 01/05/2023] Open
Abstract
Generalized arterial calcification of infancy (GACI) is an autosomal recessive disorder caused by mutations in the ENPP1 gene. It is characterized by mineralization of the arterial blood vessels, often diagnosed prenatally, and associated with death in early childhood. There is no effective treatment for this devastating disorder. We previously characterized the Enpp1asjmutant mouse as a model of GACI, and we have now explored the effect of elevated dietary magnesium (five-fold) in pregnant mothers and continuing for the first 14 weeks of postnatal life. The mothers were kept on either control diet or experimental diet supplemented with magnesium. Upon weaning at 4 weeks of age the pups were placed either on control diet or high magnesium diet. The degree of mineralization was assessed at 14 weeks of age by histopathology and a chemical calcium assay in muzzle skin, kidney and aorta. Mice placed on high magnesium diet showed little, if any, evidence of mineralization when their corresponding mothers were also placed on diet enriched with magnesium during pregnancy and nursing. The reduced ectopic mineralization in these mice was accompanied by increased calcium and magnesium content in the urine, suggesting that magnesium competes calcium-phosphate binding thereby preventing the mineral deposition. These results have implications for dietary management of pregnancies in which the fetus is suspected of having GACI. Moreover, augmenting a diet with high magnesium may be beneficial for other ectopic mineralization diseases, including nephrocalcinosis.
Collapse
|
17
|
Kranenburg G, Visseren FLJ, de Borst GJ, de Jong PA, Spiering W. Arterial stiffening and thickening in patients with pseudoxanthoma elasticum. Atherosclerosis 2018; 270:160-165. [PMID: 29432933 DOI: 10.1016/j.atherosclerosis.2018.02.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 01/25/2018] [Accepted: 02/02/2018] [Indexed: 12/22/2022]
Abstract
BACKGROUND AND AIMS Patients with pseudoxanthoma elasticum (PXE), a monogenetic calcification disease, are at high vascular risk. Although the precise arterial phenotype remains unestablished, it is hypothesized that PXE predominantly affects the medial arterial layer leading to arterial stiffening. We aimed to test this hypothesis by measuring arterial wall characteristics in PXE and comparisons with the general population and diabetes mellitus type 2 (DM2), a condition typically associated with mixed intimal and medial arterial disease. METHODS Extensive arterial wall characterization was performed in 203 PXE patients involving intima-media thickness (IMT), pulse wave velocity (PWV) and pulse pressure (PP) measurements. IMT and PWV in PXE were compared with the general population using age, sex and mean arterial pressure corrected values for each PXE patient. IMT and PP were compared between PXE and DM2 independently of sex, age and systolic blood pressure, using data of DM2 patients (n = 1033) from the Second Manifestations of ARTerial disease (SMART) cohort. RESULTS PXE patients had significantly higher IMT (mean difference 0.09 mm; 95% CI 0.07-0.12 mm) and PWV (mean difference 2.5 m/s; 95% CI 1.9-3.0 m/s) compared to the general population. IMT in PXE was lower compared to DM2 (0.72 mm; 95% CI 0.68-0.75 mm vs. 0.85 mm; 95% CI 0.83-0.87 mm, p-value<0.01), whereas PP in PXE was higher compared to DM2 (60 mmHg; 95% CI 59-62 vs. 57 mmHg; 95% CI 57-58 mmHg, p-value<0.01). CONCLUSIONS PXE patients have thicker arterial walls than the general population, but thinner arterial walls than DM2 patients at similar age. Arterial stiffening is more pronounced in PXE patients compared to DM2 patients.
Collapse
Affiliation(s)
- Guido Kranenburg
- Department of Vascular Medicine, University Medical Center Utrecht, Utrecht University, The Netherlands
| | - Frank L J Visseren
- Department of Vascular Medicine, University Medical Center Utrecht, Utrecht University, The Netherlands
| | - Gert Jan de Borst
- Department of Vascular Surgery, University Medical Center Utrecht, Utrecht University, The Netherlands
| | - Pim A de Jong
- Department of Radiology, University Medical Center Utrecht, Utrecht University, The Netherlands
| | - Wilko Spiering
- Department of Vascular Medicine, University Medical Center Utrecht, Utrecht University, The Netherlands.
| | | |
Collapse
|
18
|
Karasik A, Ledwitch KV, Arányi T, Váradi A, Roberts A, Szeri F. Boosted coupling of ATP hydrolysis to substrate transport upon cooperative estradiol-17-β-D-glucuronide binding in a Drosophila ATP binding cassette type-C transporter. FASEB J 2018; 32:669-680. [PMID: 28939593 DOI: 10.1096/fj.201700606r] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
ATP binding cassette type-C (ABCC) transporters move molecules across cell membranes upon hydrolysis of ATP; however, their coupling of ATP hydrolysis to substrate transport remains elusive. Drosophila multidrug resistance-associated protein (DMRP) is the functional ortholog of human long ABCC transporters, with similar substrate and inhibitor specificity, but higher activity. Exploiting its high activity, we kinetically dissected the catalytic mechanism of DMRP by using E2-d-glucuronide (E2G), the physiologic substrate of human ABCC. We examined the DMRP-mediated interdependence of ATP and E2G in biochemical assays. We observed E2G-dependent ATPase activity to be biphasic at subsaturating ATP concentrations, which implies at least 2 E2G binding sites on DMRP. Furthermore, transport measurements indicated strong nonreciprocal cooperativity between ATP and E2G. In addition to confirming these findings, our kinetic modeling with the Complex Pathway Simulator indicated a 10-fold decrease in the E2G-mediated activation of ATP hydrolysis upon saturation of the second E2G binding site. Surprisingly, the binding of the second E2G allowed for substrate transport with a constant rate, which tightly coupled ATP hydrolysis to transport. In summary, we show that the second E2G binding-similar to human ABCC2-allosterically stimulates transport activity of DMRP. Our data suggest that this is achieved by a significant increase in the coupling of ATP hydrolysis to transport.-Karasik, A., Ledwitch, K. V., Arányi, T., Váradi, A., Roberts, A., Szeri, F. Boosted coupling of ATP hydrolysis to substrate transport upon cooperative estradiol-17-β-D-glucuronide binding in a Drosophila ATP binding cassette type-C transporter.
Collapse
Affiliation(s)
- Agnes Karasik
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | | | - Tamás Arányi
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - András Váradi
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Arthur Roberts
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, Georgia, USA
| | - Flóra Szeri
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| |
Collapse
|
19
|
Uitto J, Udey MC. The Importance of Research Data Sharing: The Meeting Reports Section of the JID. J Invest Dermatol 2017; 137:2455-2456. [PMID: 29169457 DOI: 10.1016/j.jid.2017.10.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
20
|
Caballero D, Li Y, Fetene J, Ponsetto J, Chen A, Zhu C, Braddock DT, Bergwitz C. Intraperitoneal pyrophosphate treatment reduces renal calcifications in Npt2a null mice. PLoS One 2017; 12:e0180098. [PMID: 28704395 PMCID: PMC5509111 DOI: 10.1371/journal.pone.0180098] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 06/09/2017] [Indexed: 12/12/2022] Open
Abstract
Mutations in the proximal tubular sodium-dependent phosphate co-transporters NPT2a and NPT2c have been reported in patients with renal stone disease and nephrocalcinosis, however the relative contribution of genotype, dietary calcium and phosphate, and modifiers of mineralization such as pyrophosphate (PPi) to the formation of renal mineral deposits is unclear. In the present study, we used Npt2a-/- mice to model the renal calcifications observed in these disorders. We observed elevated urinary excretion of PPi in Npt2a-/- mice when compared to WT mice. Presence of two hypomorphic Extracellular nucleotide pyrophosphatase phosphodiesterase 1 (Enpp1asj/asj) alleles decreased urine PPi and worsened renal calcifications in Npt2a-/- mice. These studies suggest that PPi is a thus far unrecognized factor protecting Npt2a-/- mice from the development of renal mineral deposits. Consistent with this conclusion, we next showed that renal calcifications in these mice can be reduced by intraperitoneal administration of sodium pyrophosphate. If confirmed in humans, urine PPi could therefore be of interest for developing new strategies to prevent the nephrocalcinosis and nephrolithiasis seen in phosphaturic disorders.
Collapse
Affiliation(s)
- Daniel Caballero
- Department of Medicine, Section Endocrinology, Yale University School of Medicine, New Haven, CT, United States of America
| | - Yuwen Li
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, United States of America
- Department of Pediatrics, The First Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Jonathan Fetene
- Department of Medicine, Section Endocrinology, Yale University School of Medicine, New Haven, CT, United States of America
| | - Julian Ponsetto
- Department of Medicine, Section Endocrinology, Yale University School of Medicine, New Haven, CT, United States of America
| | - Alyssa Chen
- Department of Medicine, Section Endocrinology, Yale University School of Medicine, New Haven, CT, United States of America
| | - Chuanlong Zhu
- Gastroenterology Unit, Massachusetts General Hospital and Harvard Medical School, Boston, United States of America
- Department of Infectious Diseases, The First Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Demetrios T. Braddock
- Department of Pathology, Yale University School of Medicine, New Haven, CT, United States of America
| | - Clemens Bergwitz
- Department of Medicine, Section Endocrinology, Yale University School of Medicine, New Haven, CT, United States of America
- * E-mail:
| |
Collapse
|
21
|
Abstract
Pseudoxanthoma elasticum (PXE) is a genetic metabolic disease with autosomal recessive inheritance caused by mutations in the ABCC6 gene. The lack of functional ABCC6 protein leads to ectopic mineralization that is most apparent in the elastic tissues of the skin, eyes and blood vessels. The clinical prevalence of PXE has been estimated at between 1 per 100,000 and 1 per 25,000, with slight female predominance. The first clinical sign of PXE is almost always small yellow papules on the nape and sides of the neck and in flexural areas. The papules coalesce, and the skin becomes loose and wrinkled. The mid-dermal elastic fibers are short, fragmented, clumped and calcified. Dystrophic calcification of Bruch's membrane, revealed by angioid streaks, may trigger choroidal neovascularization and, ultimately, loss of central vision and blindness in late-stage disease. Lesions in small and medium-sized artery walls may result in intermittent claudication and peripheral artery disease. Cardiac complications (myocardial infarction, angina pectoris) are thought to be relatively rare but merit thorough investigation. Ischemic strokes have been reported. PXE is a metabolic disease in which circulating levels of an anti-mineralization factor are low. There is good evidence to suggest that the factor is inorganic pyrophosphate (PPi), and that the circulating low levels of PPi and decreased PPi/Pi ratio result from the lack of ATP release by hepatocytes harboring the mutant ABCC6 protein. However, the substrate(s) bound, transported or modulated by the ABCC6 protein remain unknown. More than 300 sequence variants of the ABCC6 gene have been identified. There is no cure for PXE; the main symptomatic treatments are vascular endothelial growth factor inhibitor therapy (for ophthalmic manifestations), lifestyle, lipid-lowering and dietary measures (for reducing vascular risk factors), and vascular surgery (for severe cardiovascular manifestations). Future treatment options may include gene therapy/editing and pharmacologic chaperone therapy.
Collapse
Affiliation(s)
- Dominique P Germain
- Division of Medical Genetics, University of Versailles - Saint Quentin en Yvelines, Paris-Saclay University, 2 avenue de la source de la Bièvre, F-78180, Montigny, France.
| |
Collapse
|
22
|
Uitto J, Li Q, van de Wetering K, Váradi A, Terry SF. Insights into Pathomechanisms and Treatment Development in Heritable Ectopic Mineralization Disorders: Summary of the PXE International Biennial Research Symposium-2016. J Invest Dermatol 2017; 137:790-795. [PMID: 28340679 PMCID: PMC5831331 DOI: 10.1016/j.jid.2016.12.014] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 12/07/2016] [Accepted: 12/11/2016] [Indexed: 02/06/2023]
Abstract
Pseudoxanthoma elasticum is a prototype of heritable ectopic mineralization disorders, with phenotypic overlap with generalized arterial calcification of infancy and arterial calcification due to CD73 deficiency. Recent observations have suggested that the reduced inorganic pyrophosphate/phosphate ratio is the cause of soft connective tissue mineralization in these disorders. PXE International, a patient advocacy organization, supports research in part by sponsoring biennial research symposia on these disorders; the latest meeting was held in September 2016 at Thomas Jefferson University, Philadelphia. This report summarizes the progress in pseudoxanthoma elasticum and other ectopic mineralization disorders, as presented in the symposium, with focus on translational aspects of precision medicine toward improved diagnostics and treatment development for these currently intractable disorders.
Collapse
Affiliation(s)
- Jouni Uitto
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, and PXE International Center of Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, Pennsylvania, USA.
| | - Qiaoli Li
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, and PXE International Center of Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Koen van de Wetering
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, and PXE International Center of Excellence in Research and Clinical Care, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - András Váradi
- Institute of Enzymology, RCNS, Hungarian Academy of Sciences, Budapest, Hungary
| | - Sharon F Terry
- PXE International, Washington, District of Columbia, USA
| |
Collapse
|
23
|
Abcc6 Knockout Rat Model Highlights the Role of Liver in PPi Homeostasis in Pseudoxanthoma Elasticum. J Invest Dermatol 2017; 137:1025-1032. [PMID: 28111129 DOI: 10.1016/j.jid.2016.11.042] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 11/23/2016] [Accepted: 11/25/2016] [Indexed: 12/26/2022]
Abstract
Pseudoxanthoma elasticum, a heritable ectopic mineralization disorder, is caused by mutations in the ABCC6 gene primarily expressed in the liver and the kidneys. The fundamental question on pathogenesis of pseudoxanthoma elasticum, whether lack of ABCC6 expression in liver or kidney is the primary site of molecular pathology in peripheral tissues, has not been addressed. We generated a series of Abcc6-/- rats as models of pseudoxanthoma elasticum depicting ectopic mineralization in the skin, eyes, and the arterial blood vessels. Plasma inorganic pyrophosphate (PPi) level was reduced (<30%) in the Abcc6-/- rats leading to a lowered PPi/inorganic phosphate plasma ratio. In situ liver and kidney perfusions were performed to determine the relative contribution of these organs to PPi levels in circulation. PPi levels in the perfusates both in the liver and kidney of Abcc6-/- rats were significantly reduced, but the PPi levels in the liver perfusates of wild-type rats were 10-fold higher than that in the kidney perfusates. These observations suggest a critical role of hepatic ABCC6 in contributing to plasma PPi levels, identifying liver as a target of molecular correction to counteract ectopic mineralization in pseudoxanthoma elasticum.
Collapse
|
24
|
Rasmussen MR, Nielsen KL, Laursen MR, Nielsen CB, Svendsen P, Dimke H, Christensen EI, Johannsen M, Moestrup SK. Untargeted Metabolomics Analysis of ABCC6-Deficient Mice Discloses an Altered Metabolic Liver Profile. J Proteome Res 2016; 15:4591-4600. [PMID: 27758107 DOI: 10.1021/acs.jproteome.6b00669] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Loss-of-function mutations in the transmembrane ABCC6 transport protein cause pseudoxanthoma elasticum (PXE), an ectopic, metabolic mineralization disorder that affects the skin, eye, and vessels. ABCC6 is assumed to mediate efflux of one or several small molecule compounds from the liver cytosol to the circulation. Untargeted metabolomics using liquid chromatography-mass spectrometry was employed to inspect liver cytosolic extracts from mice with targeted disruption of the Abcc6 gene. Absence of the ABCC6 protein induced an altered profile of metabolites in the liver causing accumulation of compounds as more features were upregulated than downregulated in ABCC6-deficient mice. However, no differences of the identified metabolites in liver could be detected in plasma, whereas urine reflected some of the changes. Of note, N-acetylated amino acids and pantothenic acid (vitamin B5), which is involved in acetylation reactions, were accumulated in the liver. None of the identified metabolites seems to explain mineralization in extrahepatic tissues, but the present study now shows that abrogated ABCC6 function does cause alterations in the metabolic profile of the liver in accordance with PXE being a metabolic disease originating from liver disturbance. Further studies of these changes and the further identification of yet unknown metabolites may help to clarify the liver-related pathomechanism of PXE.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | - Søren K Moestrup
- Department of Clinical Biochemistry, Pharmacology, Odense University Hospital , Odense 5000, Denmark
| |
Collapse
|
25
|
Mouse genome-wide association study identifies polymorphisms on chromosomes 4, 11, and 15 for age-related cardiac fibrosis. Mamm Genome 2016; 27:179-90. [PMID: 27126641 DOI: 10.1007/s00335-016-9634-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 03/24/2016] [Indexed: 10/21/2022]
Abstract
Dystrophic cardiac calcinosis (DCC), also called epicardial and myocardial fibrosis and mineralization, has been detected in mice of a number of laboratory inbred strains, most commonly C3H/HeJ and DBA/2J. In previous mouse breeding studies between these DCC susceptible and the DCC-resistant strain C57BL/6J, 4 genetic loci harboring genes involved in DCC inheritance were identified and subsequently termed Dyscalc loci 1 through 4. Here, we report susceptibility to cardiac fibrosis, a sub-phenotype of DCC, at 12 and 20 months of age and close to natural death in a survey of 28 inbred mouse strains. Eight strains showed cardiac fibrosis with highest frequency and severity in the moribund mice. Using genotype and phenotype information of the 28 investigated strains, we performed genome-wide association studies (GWAS) and identified the most significant associations on chromosome (Chr) 15 at 72 million base pairs (Mb) (P < 10(-13)) and Chr 4 at 122 Mb (P < 10(-11)) and 134 Mb (P < 10(-7)). At the Chr 15 locus, Col22a1 and Kcnk9 were identified. Both have been reported to be morphologically and functionally important in the heart muscle. The strongest Chr 4 associations were located approximately 6 Mb away from the Dyscalc 2 quantitative trait locus peak within the boundaries of the Extl1 gene and in close proximity to the Trim63 and Cap1 genes. In addition, a single-nucleotide polymorphism association was found on chromosome 11. This study provides evidence for more than the previously reported 4 genetic loci determining cardiac fibrosis and DCC. The study also highlights the power of GWAS in the mouse for dissecting complex genetic traits.
Collapse
|