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Harmsen IM, Visseren FL, Kok M, de Jong PA, Spiering W. Plasma lipids in Pseudoxanthoma Elasticum (PXE) patients: A comparative study with population-based reference values and Non-PXE controls. ATHEROSCLEROSIS PLUS 2024; 55:5-11. [PMID: 38221909 PMCID: PMC10784135 DOI: 10.1016/j.athplu.2023.12.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 11/10/2023] [Accepted: 12/04/2023] [Indexed: 01/16/2024]
Abstract
Background and aims - Pseudoxanthoma elasticum (PXE) is a rare genetic disease caused by pathogenic mutations in the ABCC6 gene, resulting in low values of inorganic pyrophosphate (PPi). While low PPi is thought to contribute to arterial calcification, it remains unclear whether this fully explains premature calcification in PXE. It has been hypothesized that the ABCC6 gene could be related to dyslipidemia, which could contribute to vascular calcification seen in PXE. The aim of this study is to evaluate the relation between PXE and plasma lipid concentrations in a large cohort of PXE patients compared with reference values for the general population and compared with non-PXE controls. Methods - The plasma concentrations of total cholesterol, HDL-cholesterol, tiglycerides, and LDL-cholesterol of 312 PXE patients were compared to age- and sex-matched modeled data of the general Dutch population. Differences in median lipid levels were compared with Mann-Whitney-U test. Secondly, plasma lipid concentrations of 44 PXE patients were compared to 44 not-genetically related relatives (spouses or friends), with linear models adjusted for age, sex and BMI. Results - Total cholesterol in PXE patients was 5.6 [IQR 4.6-6.4] mmol/L versus 5.3 [IQR 4.7-6.0] mmol/L (p < 0.01) in the general population; triglycerides were 1.1 [IQR 0.9-1.7] mmol/L versus 1.0 [0.7-1.4] mmol/L (p < 0.01); HDL-c was 1.4 [IQR 1.2-1.7] mmol/L versus 1.5 [IQR 1.2-1.8] mmol/L (p = 0.03) and LDL-c was 3.3 [IQR 2.7-4.1] mmol/L versus 3.2 [IQR 2.7-3.8] mmol/L (p = 0.01). In the patient control analysis with 44 pairs and age, sex and BMI adjusted, comparison with the non-PXE controls only triglycerides were significantly different (mean difference: 0.38 (0.13-0.63)). Conclusion -The lipid profiles of PXE patients are marginally different from the general population or compared to a matched control group, but the differences are unlikely to be clinically relevant. It is therefore unlikely that plasma lipids contribute to the premature vascular calcifications in PXE patients.
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Affiliation(s)
- Iris M. Harmsen
- Department of Vascular Medicine, University Medical Centre Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Frank L.J. Visseren
- Department of Vascular Medicine, University Medical Centre Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Madeleine Kok
- Department of Radiology, University Medical Centre Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Pim A. de Jong
- Department of Radiology, University Medical Centre Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Wilko Spiering
- Department of Vascular Medicine, University Medical Centre Utrecht, Utrecht University, Utrecht, the Netherlands
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Loewinger AS, Pfau M, Herrmann P, Holz FG, Pfau K. Choriocapillaris Flow Signal Impairment in Patients With Pseudoxanthoma Elasticum. Invest Ophthalmol Vis Sci 2023; 64:21. [PMID: 36809302 PMCID: PMC9946047 DOI: 10.1167/iovs.64.2.21] [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] [Indexed: 02/23/2023] Open
Abstract
Purpose To quantify choriocapillaris flow alterations in patients with pseudoxanthoma elasticum (PXE) in pre-atrophic stages and its association with structural changes of the choroid and outer retina. Methods Thirty-two eyes of 21 patients with PXE and 35 healthy eyes of 35 controls were included. The density of choriocapillaris flow signal deficits (FDs) was quantified on 6 × 6-mm optical coherence tomography angiography (OCTA) images. Spectral-domain optical coherence tomography (SD-OCT) images were analyzed for thicknesses of the choroid and outer retinal microstructure and correlated with choriocapillaris FDs in the respective Early Treatment Diabetic Retinopathy Study subfield. Results The multivariable mixed model analysis for choriocapillaris FDs revealed significantly higher FDs associated with the group (PXE patients vs. controls +13.6; 95% confidence interval [CI] 9.87-17.3; P < 0.001), with increasing age (+0.22% per year; 95% CI 0.12-0.33; P < 0.001), and with retinal location (significantly higher FDs in nasal compared to temporal subfields). Choroidal thickness (CT) did not differ significantly between both groups (P = 0.078). The CT and choriocapillaris FDs were inversely correlated (-1.92 µm per %FDs; interquartile range -2.81 to -1.03; P < 0.001). Larger values of the choriocapillaris FDs were associated with significant thinning of the overlying photoreceptor layers (outer segments: -0.21 µm per %FDs, P < 0.001; inner segments: -0.12 µm per %FDs, P = 0.001; outer nuclear layer: -0.72 µm per %FDs; P < 0.001). Conclusions Patients with PXE display significant alterations of the choriocapillaris on OCTA even in pre-atrophic stages and in the absence of significant choroidal thinning. The analysis favors choriocapillaris FDs over choroidal thickness as a potential early outcome measure for future interventional trials in PXE. Further, increased FDs in nasal compared to temporal locations mirror the centrifugal spread of Bruch's membrane calcification in PXE.
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Affiliation(s)
| | - Maximilian Pfau
- Department of Ophthalmology, University Hospital Bonn, Bonn, Germany,Ophthalmic Genetics and Visual Function Branch, National Eye Institute, Bethesda, Maryland, United States
| | - Philipp Herrmann
- Department of Ophthalmology, University Hospital Bonn, Bonn, Germany
| | - Frank G. Holz
- Department of Ophthalmology, University Hospital Bonn, Bonn, Germany
| | - Kristina Pfau
- Department of Ophthalmology, University Hospital Bonn, Bonn, Germany,Division of Epidemiology and Clinical Applications, National Eye Institute, Bethesda, Maryland, United States
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Lucci C, van den Beukel TC, Bartstra JW, Zwanenburg J, van der Kolk A, Takx R, Hendrikse J, Geerlings MI, Bos D, Spiering W, de Jong PA. Intracranial atherosclerosis in pseudoxanthoma elasticum: A case-control study. Atherosclerosis 2022; 350:19-24. [DOI: 10.1016/j.atherosclerosis.2022.04.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 04/08/2022] [Accepted: 04/13/2022] [Indexed: 11/25/2022]
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Jones VA, Patel PM, Valikodath T, Ashack KA. Dermatologic manifestations of pediatric cardiovascular diseases: Skin as a reflection of the heart. Pediatr Dermatol 2021; 38:1461-1474. [PMID: 34725847 DOI: 10.1111/pde.14841] [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] [Indexed: 11/29/2022]
Abstract
Cutaneous disease can often be an initial clue of an underlying cardiovascular disease. Many congenital conditions (ie, Noonan syndrome with multiple lentigines, Carney complex, and Fabry disease) and acquired conditions may present initially with specific cutaneous features that should prompt clinicians to conduct a full cardiac workup. Given the extensive number of conditions with both cardiovascular and cutaneous findings, this review will focus on diseases with cardiocutaneous pathology with hopes of raising clinician awareness of these associations to decrease morbidity and mortality, as several of these diseases often result in fatal outcomes.
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Affiliation(s)
- Virginia A Jones
- Department of Dermatology, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Payal M Patel
- Department of Dermatology, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Tom Valikodath
- Cincinnati Children's Hospital Medical Center Heart Institute, Cincinnati, Ohio, USA
| | - Kurt A Ashack
- Dermatology Associates of West Michigan, Grand Rapids, Michigan, USA
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Bartstra JW, Risseeuw S, de Jong PA, van Os B, Kalsbeek L, Mol C, Baas AF, Verschuere S, Vanakker O, Florijn RJ, Hendrikse J, Mali W, Imhof S, Ossewaarde-van Norel J, van Leeuwen R, Spiering W. Genotype-phenotype correlation in pseudoxanthoma elasticum. Atherosclerosis 2021; 324:18-26. [PMID: 33812167 DOI: 10.1016/j.atherosclerosis.2021.03.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 02/26/2021] [Accepted: 03/10/2021] [Indexed: 12/20/2022]
Abstract
BACKGROUND AND AIMS Pseudoxanthoma elasticum (PXE) is caused by variants in the ABCC6 gene. It results in calcification in the skin, peripheral arteries and the eyes, but has considerable phenotypic variability. We investigated the association between the ABCC6 genotype and calcification and clinical phenotypes in these different organs. METHODS ABCC6 sequencing was performed in 289 PXE patients. Genotypes were grouped as two truncating, mixed, or two non-truncating variants. Arterial calcification mass was quantified on whole body, low dose CT scans; and peripheral arterial disease was measured with the ankle brachial index after treadmill test. The presence of pseudoxanthoma in the skin was systematically scored. Ophthalmological phenotypes were the length of angioid streaks as a measure of Bruchs membrane calcification, the presence of choroidal neovascularizations, severity of macular atrophy and visual acuity. Regression models were built to test the age and sex adjusted genotype-phenotype association. RESULTS 158 patients (median age 51 years) had two truncating variants, 96 (median age 54 years) a mixed genotype, 18 (median age 47 years) had two non-truncating variants. The mixed genotype was associated with lower peripheral (β: 0.39, 95%CI:-0.62;-0.17) and total (β: 0.28, 95%CI:-0.47;-0.10) arterial calcification mass scores, and lower prevalence of choroidal neovascularizations (OR: 0.41 95%CI:0.20; 0.83) compared to two truncating variants. No association with pseudoxanthomas was found. CONCLUSIONS PXE patients with a mixed genotype have less severe arterial and ophthalmological phenotypes than patients with two truncating variants in the ABCC6 gene. Research into environmental and genetic modifiers might provide further insights into the unexplained phenotypic variability.
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Affiliation(s)
- Jonas W Bartstra
- Department of Radiology, University Medical Center Utrecht, Utrecht University, the Netherlands
| | - Sara Risseeuw
- Department of Ophthalmology, University Medical Center Utrecht, Utrecht University, the Netherlands
| | - Pim A de Jong
- Department of Radiology, University Medical Center Utrecht, Utrecht University, the Netherlands
| | - Bram van Os
- Department of Radiology, University Medical Center Utrecht, Utrecht University, the Netherlands
| | - Lianne Kalsbeek
- Department of Radiology, University Medical Center Utrecht, Utrecht University, the Netherlands
| | - Chris Mol
- Department of Radiology, University Medical Center Utrecht, Utrecht University, the Netherlands
| | - Annette F Baas
- Department of Genetics, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Shana Verschuere
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Olivier Vanakker
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Ralph J Florijn
- Department of Clinical Genetics, Academic Medical Center, Amsterdam, the Netherlands
| | - Jeroen Hendrikse
- Department of Radiology, University Medical Center Utrecht, Utrecht University, the Netherlands
| | - Willem Mali
- Department of Radiology, University Medical Center Utrecht, Utrecht University, the Netherlands
| | - Saskia Imhof
- Department of Ophthalmology, University Medical Center Utrecht, Utrecht University, the Netherlands
| | | | - Redmer van Leeuwen
- Department of Ophthalmology, University Medical Center Utrecht, Utrecht University, the Netherlands
| | - Wilko Spiering
- Department of Vascular Medicine, University Medical Center Utrecht, Utrecht University, the Netherlands.
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Terry SF. The Human Face of ABCC6. FEBS Lett 2020; 594:4151-4157. [DOI: 10.1002/1873-3468.14002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 11/09/2020] [Accepted: 11/10/2020] [Indexed: 01/08/2023]
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Kranenburg G, de Jong PA, Bartstra JW, Lagerweij SJ, Lam MG, Ossewaarde-van Norel J, Risseeuw S, van Leeuwen R, Imhof SM, Verhaar HJ, de Vries JJ, Slart RHJA, Luurtsema G, den Harder AM, Visseren FLJ, Mali WP, Spiering W. Etidronate for Prevention of Ectopic Mineralization in Patients With Pseudoxanthoma Elasticum. J Am Coll Cardiol 2019. [PMID: 29519353 DOI: 10.1016/j.jacc.2017.12.062] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND In pseudoxanthoma elasticum (PXE), low pyrophosphate levels may cause ectopic mineralization, leading to skin changes, visual impairment, and peripheral arterial disease. OBJECTIVES The authors hypothesized that etidronate, a pyrophosphate analog, might reduce ectopic mineralization in PXE. METHODS In the Treatment of Ectopic Mineralization in Pseudoxanthoma Elasticum trial, adults with PXE and leg arterial calcifications (n = 74) were randomly assigned to etidronate or placebo (cyclical 20 mg/kg for 2 weeks every 12 weeks). The primary outcome was ectopic mineralization, quantified with 18fluoride positron emission tomography scans as femoral arterial wall target-to-background ratios (TBRfemoral). Secondary outcomes were computed tomography arterial calcification and ophthalmological changes. Safety outcomes were bone density, serum calcium, and phosphate. RESULTS During 12 months of follow-up, the TBRfemoral increased 6% (interquartile range [IQR]: -12% to 25%) in the etidronate group and 7% (IQR: -9% to 32%) in the placebo group (p = 0.465). Arterial calcification decreased 4% (IQR: -11% to 7%) in the etidronate group and increased 8% (IQR: -1% to 20%) in the placebo group (p = 0.001). Etidronate treatment was associated with significantly fewer subretinal neovascularization events (1 vs. 9, p = 0.007). Bone density decreased 4% ± 12% in the etidronate group and 6% ± 9% in the placebo group (p = 0.374). Hypocalcemia (<2.20 mmol/l) occurred in 3 versus 1 patient (8.1% vs. 2.7%, p = 0.304). Eighteen patients (48.6%) treated with etidronate, compared with 0 patients treated with placebo (p < 0.001), experienced hyperphosphatemia (>1.5 mmol/l) and recovered spontaneously. CONCLUSIONS In patients with PXE, etidronate reduced arterial calcification and subretinal neovascularization events but did not lower femoral 18fluoride sodium positron emission tomography activity compared with placebo, without important safety issues. (Treatment of Ectopic Mineralization in Pseudoxanthoma elasticum; NTR5180).
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Affiliation(s)
- Guido Kranenburg
- Department of Vascular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Pim A de Jong
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Jonas W Bartstra
- Department of Vascular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Suzanne J Lagerweij
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Marnix G Lam
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | | | - Sara Risseeuw
- Department of Ophthalmology, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Redmer van Leeuwen
- Department of Ophthalmology, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Saskia M Imhof
- Department of Ophthalmology, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Harald J Verhaar
- Department of Geriatric Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Job J de Vries
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Riemer H J A Slart
- Medical Imaging Center, Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Gert Luurtsema
- Medical Imaging Center, Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Annemarie M den Harder
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Frank L J Visseren
- Department of Vascular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Willem P Mali
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Wilko Spiering
- Department of Vascular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands.
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Khan FF, Erfan M, Kanwal N, Naeem M. Whole exome sequencing identified three ABCC6 variants in two Pakistani families with pseudoxanthoma elasticum phenotype. Mol Biol Rep 2019; 46:1363-1368. [DOI: 10.1007/s11033-018-04581-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2018] [Accepted: 12/18/2018] [Indexed: 11/30/2022]
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Schantl AE, Ivarsson ME, Leroux JC. Investigational Pharmacological Treatments for Vascular Calcification. ADVANCED THERAPEUTICS 2018. [DOI: 10.1002/adtp.201800094] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Antonia E. Schantl
- Institute of Pharmaceutical Sciences; ETH Zurich; Vladimir-Prelog-Weg 3 8093 Zurich Switzerland
| | | | - Jean-Christophe Leroux
- Institute of Pharmaceutical Sciences; ETH Zurich; Vladimir-Prelog-Weg 3 8093 Zurich Switzerland
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Kranenburg G, Baas AF, de Jong PA, Asselbergs FW, Visseren FLJ, Spiering W. The prevalence of pseudoxanthoma elasticum: Revised estimations based on genotyping in a high vascular risk cohort. Eur J Med Genet 2018; 62:90-92. [PMID: 29800625 DOI: 10.1016/j.ejmg.2018.05.020] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 03/23/2018] [Accepted: 05/21/2018] [Indexed: 11/25/2022]
Abstract
BACKGROUND Pseudoxanthoma elasticum (PXE), an autosomal recessive systemic calcification disorder, is caused by mutations in the ABCC6-gene and associated with severe visual impairment and peripheral arterial disease. Given the progress in development of a therapy for PXE, more precise estimations of its prevalence are warranted. METHODS We genotyped the four most common ABCC6 mutations (c.3421C > T, c.4182delG, c.3775delT, c.2787+1G > T), together accounting for half of all ABCC6 mutations identified in PXE patients from the Dutch population, in a Dutch high vascular risk cohort (n = 7893). The obtained allele frequencies were used to estimate the prevalence of PXE using the Hardy-Weinberg equilibrium. RESULTS The carrier frequency of ABCC6 was 0.60% for c.3421C > T, 0.17% for c.4182delG, 0.05% for c.3775delT and 0.03% for c.2787+1G > T. The prevalence of PXE based upon the allele frequencies of these four mutations was estimated as 1 per 56,000 (95%CI 1 per 35,000-97,000). CONCLUSION The prevalence of PXE is at least 1 per 56,000 meaning that there would be at least 307 affected individuals in the Netherlands that may benefit from a potential upcoming treatment. Since this estimate is based on mutations together accounting for half of all ABCC6 mutations identified among PXE patients, the actual prevalence will probably be higher.
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Affiliation(s)
- Guido Kranenburg
- Department of Vascular Medicine, University Medical Center Utrecht, Utrecht University, the Netherlands
| | - Annette F Baas
- Department of Medical Genetics, University Medical Center Utrecht, Utrecht University, the Netherlands
| | - Pim A de Jong
- Department of Radiology, University Medical Center Utrecht, Utrecht University, the Netherlands
| | - Folkert W Asselbergs
- Department of Cardiology, University Medical Center Utrecht, Utrecht University, the Netherlands
| | - Frank L J Visseren
- Department of Vascular Medicine, University Medical Center Utrecht, Utrecht University, the Netherlands
| | - Wilko Spiering
- Department of Vascular Medicine, University Medical Center Utrecht, Utrecht University, the Netherlands.
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ABCC6 Gene Analysis in 20 Japanese Patients with Angioid Streaks Revealing Four Frequent and Two Novel Variants and Pseudodominant Inheritance. J Ophthalmol 2017; 2017:1079687. [PMID: 28912966 PMCID: PMC5585540 DOI: 10.1155/2017/1079687] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 08/06/2017] [Indexed: 11/18/2022] Open
Abstract
Purpose To report the spectrum of ABCC6 variants in Japanese patients with angioid streaks (AS). Patients and Methods This was a single-center cohort study. The medical records of 20 patients with AS from 18 unrelated Japanese families were retrospectively reviewed. Screening of the ABCC6 gene (exons 1 to 31) was performed using PCR-based Sanger sequencing. Results Eight ABCC6 variants were identified as candidate disease-causing variants. These eight variants included five known variants (p.Q378X, p.R419Q, p.V848CfsX83, p.R1114C, and p.R1357W), one previously reported variant (p.N428S) of unknown significance, and two novel variants (c.1939C>T [p.H647Y] and c.3374C>T [p.S1125F]); the three latter variants were determined to be variants of significance. The following four variants were frequently identified: p.V848CfsX83 (14/40 alleles, 35.0%), p.Q378X (7/40 alleles, 17.5%), p.R1357W (6/40 alleles, 15.0%), and p.R419Q (4/40 alleles, 10.0%). The ABCC6 variants were identified in compound heterozygous or homozygous states in 13 of 18 probands. Two families showed a pseudodominant inheritance pattern. Pseudoxanthoma elasticum was seen in 15 of 17 patients (88.2%) who underwent dermatological examination. Conclusions We identified disease-causing ABCC6 variants that were in homozygous or compound heterozygous states in 13 of 18 families (72.2%). Our results indicated that ABCC6 variants play a significant role in patients with AS in the Japanese population.
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Moitra K, Garcia S, Jaldin M, Etoundi C, Cooper D, Roland A, Dixon P, Reyes S, Turan S, Terry S, Dean M. ABCC6 and Pseudoxanthoma Elasticum: The Face of a Rare Disease from Genetics to Advocacy. Int J Mol Sci 2017; 18:ijms18071488. [PMID: 28696355 PMCID: PMC5535978 DOI: 10.3390/ijms18071488] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 06/12/2017] [Accepted: 06/26/2017] [Indexed: 12/20/2022] Open
Abstract
Pseudoxanthoma elasticum (PXE) is an autosomal recessive disorder characterized by the mineralization of connective tissues in the body. Primary manifestation of PXE occurs in the tissues of the skin, eyes, and cardiovascular system. PXE is primarily caused by mutations in the ABCC6 gene. The ABCC6 gene encodes the trans-membrane protein ABCC6, which is highly expressed in the kidneys and liver. PXE has high phenotypic variability, which may possibly be affected by several modifier genes. Disease advocacy organizations have had a pivotal role in bringing rare disease research to the forefront and in helping to sustain research funding for rare genetic diseases in order to help find a treatment for these diseases, pseudoxanthoma elasticum included. Because of these initiatives, individuals affected by these conditions benefit by being scientifically informed about their condition, having an effective support mechanism, and also by contributing to scientific research efforts and banking of biological samples. This rapid progress would not have been possible without the aid of disease advocacy organizations such as PXE International.
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Affiliation(s)
- Karobi Moitra
- Department of Biology, Trinity Washington University, College Of Arts and Sciences, 125 Michigan Avenue NE, Washington, DC 20017, USA.
| | - Sonia Garcia
- Department of Biology, Trinity Washington University, College Of Arts and Sciences, 125 Michigan Avenue NE, Washington, DC 20017, USA.
- PXE International, 4301 Connecticut Avenue NW, Suite 404, Washington, DC 20008, USA.
| | - Michelle Jaldin
- Department of Biology, Trinity Washington University, College Of Arts and Sciences, 125 Michigan Avenue NE, Washington, DC 20017, USA.
- PXE International, 4301 Connecticut Avenue NW, Suite 404, Washington, DC 20008, USA.
| | - Clementine Etoundi
- Department of Biology, Trinity Washington University, College Of Arts and Sciences, 125 Michigan Avenue NE, Washington, DC 20017, USA.
| | - Donna Cooper
- Department of Biology, Trinity Washington University, College Of Arts and Sciences, 125 Michigan Avenue NE, Washington, DC 20017, USA.
| | - Anna Roland
- Department of Biology, Trinity Washington University, College Of Arts and Sciences, 125 Michigan Avenue NE, Washington, DC 20017, USA.
| | - Patrice Dixon
- Department of Biology, Trinity Washington University, College Of Arts and Sciences, 125 Michigan Avenue NE, Washington, DC 20017, USA.
| | - Sandra Reyes
- Department of Biology, Trinity Washington University, College Of Arts and Sciences, 125 Michigan Avenue NE, Washington, DC 20017, USA.
| | - Sevilay Turan
- Department of Biology, Trinity Washington University, College Of Arts and Sciences, 125 Michigan Avenue NE, Washington, DC 20017, USA.
| | - Sharon Terry
- PXE International, 4301 Connecticut Avenue NW, Suite 404, Washington, DC 20008, USA.
| | - Michael Dean
- Laboratory of Translational Genomics, The Division of Cancer Epidemiology and Genetics (DCEG), National Cancer Institute, National Institutes of Health, Gaithersburg, MD 20885, USA.
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Cerebral disease in a nationwide Dutch pseudoxanthoma elasticum cohort with a systematic review of the literature. J Neurol Sci 2017; 373:167-172. [DOI: 10.1016/j.jns.2016.12.053] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 11/29/2016] [Accepted: 12/26/2016] [Indexed: 01/09/2023]
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Kranenburg G, de Jong PA, Mali WP, Attrach M, Visseren FL, Spiering W. Prevalence and severity of arterial calcifications in pseudoxanthoma elasticum (PXE) compared to hospital controls. Novel insights into the vascular phenotype of PXE. Atherosclerosis 2017; 256:7-14. [DOI: 10.1016/j.atherosclerosis.2016.11.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 10/27/2016] [Accepted: 11/10/2016] [Indexed: 01/23/2023]
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Li Q, Arányi T, Váradi A, Terry SF, Uitto J. Research Progress in Pseudoxanthoma Elasticum and Related Ectopic Mineralization Disorders. J Invest Dermatol 2016; 136:550-556. [PMID: 26902123 PMCID: PMC4765001 DOI: 10.1016/j.jid.2015.10.065] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Heritable ectopic mineralization disorders represent a phenotypically diverse group of conditions characterized by deposition of calcium phosphate complexes in soft connective tissues. The prototype of such conditions is pseudoxanthoma elasticum, and related conditions with overlapping clinical features include generalized arterial calcification of infancy and arterial calcification due to CD73 deficiency. Molecular genetic investigations have revealed mutations in the genes physiologically involved in generation of inorganic pyrophosphate and inorganic phosphate, and the findings suggest a unifying pathomechanism relating to reduced inorganic pyrophosphate/inorganic phosphate ratio. This hypothesis is based on the notion that inorganic pyrophosphate serves as a powerful inhibitor of mineralization, whereas inorganic phosphate is a promineralization factor, and an appropriate inorganic pyrophosphate/inorganic phosphate ratio is critical for prevention of ectopic mineralization under homeostatic conditions.
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Affiliation(s)
- Qiaoli Li
- Department of Dermatology and Cutaneous Biology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Tamás Arányi
- Institute of Enzymology, RCNS, Hungarian Academy of Science, Budapest, Hungary
| | - András Váradi
- Institute of Enzymology, RCNS, Hungarian Academy of Science, Budapest, Hungary
| | | | - Jouni Uitto
- Department of Dermatology and Cutaneous Biology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA.
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Li Q, Sundberg JP, Levine MA, Terry SF, Uitto J. The effects of bisphosphonates on ectopic soft tissue mineralization caused by mutations in the ABCC6 gene. Cell Cycle 2015; 14:1082-9. [PMID: 25607347 DOI: 10.1080/15384101.2015.1007809] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Pseudoxanthoma elasticum (PXE) and generalized arterial calcification of infancy (GACI) are heritable ectopic mineralization disorders. Most cases of PXE and many cases of GACI harbor mutations in the ABCC6 gene. There is no effective treatment for these disorders. We explored the potential efficacy of bisphosphonates to prevent ectopic calcification caused by ABCC6 mutations by feeding Abcc6(-/-) mice with diet containing etidronate disodium (ETD) or alendronate sodium trihydrate (AST) in quantities corresponding to 1x, 5x, or 12x of the doses used to treat osteoporosis in humans. The mice were placed on diet at 4 weeks of age, and the degree of mineralization was assessed at 12 weeks by quantitation of the calcium deposits in the dermal sheath of vibrissae, a progressive biomarker of the mineralization, by computerized morphometry of histopathologic sections and by direct chemical assay of calcium. We found that ETD, but not AST, at the 12x dosage, significantly reduced mineralization, suggesting that selected bisphosphonates may be helpful for prevention of mineral deposits in PXE and GACI caused by mutations in the ABCC6 gene, when combined with careful monitoring of efficacy and potential side-effects.
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Affiliation(s)
- Qiaoli Li
- a Department of Dermatology and Cutaneous Biology; Sidney Kimmel Medical College ; Thomas Jefferson University ; Philadelphia , PA USA
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19
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Abstract
Genetic skin diseases, or genodermatoses, often have extracutaneous manifestations. Ocular manifestations in particular can have significant clinical implications, like blindness. Other manifestations, such as the corneal opacities that occur in X-linked ichthyosis, are asymptomatic but characteristic of a particular genodermatosis. Ophthalmologic examination can aid in diagnosis when characteristic findings are seen. The genodermatoses with ocular manifestations will be reviewed, but neurocutaneous, syndromes, genetic pigmentary disorders, and genetic metabolic diseases are not included because they are covered elsewhere in this issue.
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Affiliation(s)
- Melinda Jen
- Section of Pediatric Dermatology, Children's Hospital of Philadelphia; Departments of Pediatrics and Dermatology, Perelman School of Medicine at the University of Pennsylvania, 3550 Market St, Second floor, Philadelphia, PA, 19104.
| | - Sudha Nallasamy
- The Vision Center, Children's Hospital Los Angeles; Department of Ophthalmology, Keck School of Medicine, University of Southern California, 4650 Sunset Blvd, MS #88, Los Angeles, CA, 90027
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Marconi B, Bobyr I, Campanati A, Molinelli E, Consales V, Brisigotti V, Scarpelli M, Racchini S, Offidani A. Pseudoxanthoma elasticum and skin: Clinical manifestations, histopathology, pathomechanism, perspectives of treatment. Intractable Rare Dis Res 2015; 4:113-22. [PMID: 26361562 PMCID: PMC4561240 DOI: 10.5582/irdr.2015.01014] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Revised: 06/09/2015] [Accepted: 06/10/2015] [Indexed: 01/10/2023] Open
Abstract
Pseudoxantoma elasticum (PXE), also known as Groenblad-Strandberg syndrome, is a rare heritable disease with an estimated prevalence of 1:50,000 in the general population. PXE is considered a prototype of multisystem ectopic mineralization disorders and it is characterized by aberrant mineralization of soft connective tissue with degeneration of the elastic fibers, involving primarily the eyes, the cardiovascular system, and the skin. Cutaneous lesions consist of small, asymptomatic, yellowish papules or larger coalescent plaques, typically located on the neck and the flexural areas. PXE is caused by mutations in the ABCC6 (ATP-binding cassette subfamily C member 6) gene that encodes a transmembrane ATP binding efflux transporter, normally expressed in the liver and the kidney; however, the exact mechanism of ectopic mineralization remains largely unknown. The histological examination of cutaneous lesions, revealing accumulation of pleomorphic elastic structures in middermis, is essential for the definitive diagnosis of PXE, excluding PXE-like conditions. PXE is currently an intractable disease; although the cutaneous findings primarily present a cosmetic problem, they signify the risk for development of ocular and cardiovascular complications associated with considerable morbidity and mortality. The purpose of this review is to present a comprehensive overview of this rare form of hereditary connective tissue disorders, focus on the pathogenesis, the clinical manifestation, and the differential diagnosis of PXE. Emphasis is also placed on the management of cutaneous lesions and treatment perspectives of PXE.
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Affiliation(s)
- Barbara Marconi
- Dermatological Unit, Department of Clinical and Molecular Sciences, Polytehnic Marche University, Ancona, Italty
| | - Ivan Bobyr
- Dermatological Unit, Department of Clinical and Molecular Sciences, Polytehnic Marche University, Ancona, Italty
| | - Anna Campanati
- Dermatological Unit, Department of Clinical and Molecular Sciences, Polytehnic Marche University, Ancona, Italty
- Address correspondence to: Dr. Anna Campanati, Dermatological Unit, Department of Clinical and Molecular Sciences, Polytechnic Marche University, Via Conca 71, Ancona 60020, Italty. E-mail:
| | - Elisa Molinelli
- Dermatological Unit, Department of Clinical and Molecular Sciences, Polytehnic Marche University, Ancona, Italty
| | - Veronica Consales
- Dermatological Unit, Department of Clinical and Molecular Sciences, Polytehnic Marche University, Ancona, Italty
| | - Valerio Brisigotti
- Dermatological Unit, Department of Clinical and Molecular Sciences, Polytehnic Marche University, Ancona, Italty
| | - Marina Scarpelli
- Institute of Pathological Anatomy and Histopathology, Polytechnic University Marche, Ancona, Italty
| | - Stefano Racchini
- Institute of Pathological Anatomy and Histopathology, Polytechnic University Marche, Ancona, Italty
| | - Annamaria Offidani
- Dermatological Unit, Department of Clinical and Molecular Sciences, Polytehnic Marche University, Ancona, Italty
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21
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Uitto J, Wang G. Molecular Genetics of Heritable Skin Diseases: Pseudoxanthoma Elasticum as a Paradigm of China-US Collaboration. J Investig Dermatol Symp Proc 2015; 17:20-21. [PMID: 26067309 DOI: 10.1038/jidsymp.2015.17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Affiliation(s)
- Jouni Uitto
- Department of Dermatology and Cutaneous Biology, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Gang Wang
- Department of Dermatology, The Fourth Military Medical University, Xijing Hospital, Xi'an, Peoples Republic of China
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22
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South AP, Li Q, Uitto J. Next-generation sequencing for mutation detection in heritable skin diseases: the paradigm of pseudoxanthoma elasticum. J Invest Dermatol 2015; 135:937-940. [PMID: 25785945 DOI: 10.1038/jid.2014.521] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Next-generation sequencing applied either to the entire genome or to a subset, such as a whole exome, has revolutionized the search for pathogenic mutations in heritable diseases, including genodermatoses. In this issue, Hosen et al. applied whole-exome sequencing to identify potential pathogenic mutations in four candidate genes associated with pseudoxanthoma elasticum, the prototype of ectopic mineralization disorders. The study highlights the advantages of this approach over traditional Sanger sequencing, including expedience and cost, but it also illustrates some of the challenges encountered in implementing this rapidly evolving technology.
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Affiliation(s)
- Andrew P South
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Qiaoli Li
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Jouni Uitto
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania, USA.
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Jin L, Jiang Q, Wu Z, Shao C, Zhou Y, Yang L, Uitto J, Wang G. Genetic heterogeneity of pseudoxanthoma elasticum: the Chinese signature profile of ABCC6 and ENPP1 mutations. J Invest Dermatol 2015; 135:1294-1302. [PMID: 25615550 PMCID: PMC4402129 DOI: 10.1038/jid.2015.10] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Revised: 12/09/2014] [Accepted: 12/16/2014] [Indexed: 12/28/2022]
Abstract
Pseudoxanthoma elasticum (PXE), an autosomal recessive disorder characterized by ectopic mineralization, is caused by mutations in the ABCC6 gene. We examined clinically 29 Chinese PXE patients from unrelated families, so far the largest cohort of Asian PXE patients. In a subset of 22 patients, we sequenced ABCC6 and another candidate gene, ENPP1, and conducted pathogenicity analyses for each variant. We identified a total of 17 distinct mutations in ABCC6, 15 of them being, to our knowledge, previously unreported, including 5 frameshift and 10 missense variants. In addition, a missense mutation in combination with a recurrent nonsense mutation in ENPP1 was discovered in a pediatric PXE case. No cases with p.R1141X or del23-29 mutations, common in Caucasian patient populations, were identified. The 10 missense mutations in ABCC6 were expressed in the mouse liver via hydrodynamic tail-vein injections. One mutant protein showed cytoplasmic accumulation indicating abnormal subcellular trafficking, while the other nine mutants showed correct plasma membrane location. These nine mutations were further investigated for their pathogenicity using a recently developed zebrafish mRNA rescue assay. Minimal rescue of the morpholino-induced phenotype was achieved with eight of the nine mutant human ABCC6 mRNAs tested, implying pathogenicity. This study demonstrates that the Chinese PXE population harbors unique ABCC6 mutations. These genetic data have implications for allele-specific therapy currently being developed for PXE.
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Affiliation(s)
- Liang Jin
- Department of Dermatology, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Qiujie Jiang
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Zhengsheng Wu
- Department of Dermatology, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Changxia Shao
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Yong Zhou
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania, USA; Department of Dermatology, PLA General Hospital, Beijing, China
| | - Luting Yang
- Department of Dermatology, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Jouni Uitto
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania, USA.
| | - Gang Wang
- Department of Dermatology, Xijing Hospital, Fourth Military Medical University, Xi'an, China.
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Sies K, Ruzicka T. [Pseudozanthoma elasticum]. MMW Fortschr Med 2015; 157:60-61. [PMID: 26012460 DOI: 10.1007/s15006-015-2974-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Affiliation(s)
- Katharina Sies
- , Habsburgerstr. 55, D-79104, Freiburg i. Br., Deutschland,
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Pseudoxanthoma Elasticum Treatment with Fractional CO2 Laser. PLASTIC AND RECONSTRUCTIVE SURGERY-GLOBAL OPEN 2014; 2:e219. [PMID: 25426402 PMCID: PMC4229278 DOI: 10.1097/gox.0000000000000173] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2014] [Accepted: 07/10/2014] [Indexed: 12/24/2022]
Abstract
SUMMARY Pseudoxanthoma elasticum (PE) is a rare genetic disease characterized by calcification and fragmentation of elastic fibers of the skin, retina, and cardiovascular system. We report a case of PE in which fractional carbon dioxide laser treatment was successfully used to achieve improvement of the cervical skin with 2-year follow-up, in a patient with Fitzpatrick skin type IV. After the fifth session, the patient presented with a local herpes infection. The postlaser reaction of the PE skin was similar to that of the normal skin, in terms of the duration of redness, pain, swelling, and duration of crusting. The overall cosmetic result was satisfactory, with improvement in skin texture, irregularity, volume, and distensibility. The herpetic infection reinforces the value of antiviral prophylaxis during laser treatment of extrafacial areas.
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26
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Kuzaj P, Kuhn J, Michalek RD, Karoly ED, Faust I, Dabisch-Ruthe M, Knabbe C, Hendig D. Large-scaled metabolic profiling of human dermal fibroblasts derived from pseudoxanthoma elasticum patients and healthy controls. PLoS One 2014; 9:e108336. [PMID: 25265166 PMCID: PMC4181624 DOI: 10.1371/journal.pone.0108336] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 08/29/2014] [Indexed: 12/18/2022] Open
Abstract
Mutations in the ABC transporter ABCC6 were recently identified as cause of Pseudoxanthoma elasticum (PXE), a rare genetic disorder characterized by progressive mineralization of elastic fibers. We used an untargeted metabolic approach to identify biochemical differences between human dermal fibroblasts from healthy controls and PXE patients in an attempt to find a link between ABCC6 deficiency, cellular metabolic alterations and disease pathogenesis. 358 compounds were identified by mass spectrometry covering lipids, amino acids, peptides, carbohydrates, nucleotides, vitamins and cofactors, xenobiotics and energy metabolites. We found substantial differences in glycerophospholipid composition, leucine dipeptides, and polypeptides as well as alterations in pantothenate and guanine metabolism to be significantly associated with PXE pathogenesis. These findings can be linked to extracellular matrix remodeling and increased oxidative stress, which reflect characteristic hallmarks of PXE. Our study could facilitate a better understanding of biochemical pathways involved in soft tissue mineralization.
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Affiliation(s)
- Patricia Kuzaj
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany
| | - Joachim Kuhn
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany
| | - Ryan D. Michalek
- Metabolon, Inc., Durham, North Carolina, United States of America
| | - Edward D. Karoly
- Metabolon, Inc., Durham, North Carolina, United States of America
| | - Isabel Faust
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany
| | - Mareike Dabisch-Ruthe
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany
| | - Cornelius Knabbe
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany
| | - Doris Hendig
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany
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Li Y, Cui Y, Zhao H, Wang C, Liu X, Han J. Pseudoxanthoma elasticum: A review of 86 cases in China. Intractable Rare Dis Res 2014; 3:75-8. [PMID: 25364647 PMCID: PMC4214240 DOI: 10.5582/irdr.2014.01011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 08/07/2014] [Accepted: 08/26/2014] [Indexed: 11/05/2022] Open
Abstract
Pseudoxanthoma elasticum (PXE) is a type of rare hereditary disease that affects connective tissue. PXE is found around the world, and its epidemiology in China is still unclear. A database search revealed that 86 patients in total were reported in China from 1985 to 2013. The vast majority of these reports concern single, sporadic cases. This review summarizes the clinical characteristics of PXE and its treatment in China. The hope is to provide a reliable basis for studies on the incidence of PXE and for formulation of relevant policies in the future.
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Affiliation(s)
- Yan Li
- Key Laboratory for Biotech Drugs of the Ministry of Health, Key Laboratory for Rare Disease of Shandong Province, Shandong Medicinal Biotechnology Center, Shandong Academy of Medical Sciences, Ji'nan, Shandong, China
- School of Medicine and Life Sciences, University of Jinan-Shandong Academy of Medical Science, Ji'nan, Shandong, China
| | - Yazhou Cui
- Key Laboratory for Biotech Drugs of the Ministry of Health, Key Laboratory for Rare Disease of Shandong Province, Shandong Medicinal Biotechnology Center, Shandong Academy of Medical Sciences, Ji'nan, Shandong, China
| | - Heng Zhao
- Key Laboratory for Biotech Drugs of the Ministry of Health, Key Laboratory for Rare Disease of Shandong Province, Shandong Medicinal Biotechnology Center, Shandong Academy of Medical Sciences, Ji'nan, Shandong, China
- School of Medicine and Life Sciences, University of Jinan-Shandong Academy of Medical Science, Ji'nan, Shandong, China
| | - Chao Wang
- Key Laboratory for Biotech Drugs of the Ministry of Health, Key Laboratory for Rare Disease of Shandong Province, Shandong Medicinal Biotechnology Center, Shandong Academy of Medical Sciences, Ji'nan, Shandong, China
- School of Medicine and Life Sciences, University of Jinan-Shandong Academy of Medical Science, Ji'nan, Shandong, China
| | - Xiao Liu
- Key Laboratory for Biotech Drugs of the Ministry of Health, Key Laboratory for Rare Disease of Shandong Province, Shandong Medicinal Biotechnology Center, Shandong Academy of Medical Sciences, Ji'nan, Shandong, China
- School of Medicine and Life Sciences, University of Jinan-Shandong Academy of Medical Science, Ji'nan, Shandong, China
| | - Jinxiang Han
- Key Laboratory for Biotech Drugs of the Ministry of Health, Key Laboratory for Rare Disease of Shandong Province, Shandong Medicinal Biotechnology Center, Shandong Academy of Medical Sciences, Ji'nan, Shandong, China
- Address correspondence to: Dr. Jinxiang Han, Key Laboratory for Rare Disease Research of Shandong Province, Key Laboratory for Biotech Drugs of the Ministry of Health, Shandong Medical Biotechnological Center, Shandong Academy of Medical Sciences, Ji'nan, Shandong 250062, China. E-mail:
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Li Q, Baker J, Kowalczyk J, Jiang Q, Uitto J, Schachner L. Paediatric pseudoxanthoma elasticum with cardiovascular involvement. Br J Dermatol 2014; 169:1148-51. [PMID: 23746223 DOI: 10.1111/bjd.12462] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/02/2013] [Indexed: 12/20/2022]
Abstract
BACKGROUND Pseudoxanthoma elasticum (PXE) is characterized by aberrant mineralization of connective tissues, causing considerable morbidity and mortality. The disease is typically of late onset, the skin manifestations first being noted in the teens or later. Another aberrant mineralization disorder, generalized arterial calcification of infancy (GACI), is present at birth and can demonstrate a phenotypic overlap with PXE. OBJECTIVES A patient with PXE was noted to have skin findings as early as at 6 years of age, with cardiovascular involvement. The purpose of this study was to examine the genetic basis of this phenotypic presentation in the spectrum of PXE/GACI. METHODS The patient's genotype was studied by sequencing ABCC6 and ENPP1, genes known to be associated with PXE and/or GACI. RESULTS Screening of the ABCC6 gene revealed two pathogenetic mutations, p.R1141X and g.del23-29. Analysis of the ENPP1 gene failed to demonstrate the presence of mutations. CONCLUSIONS This study demonstrates the presence of cutaneous findings of PXE in an 8-year-old paediatric patient, with cardiovascular involvement, illustrating the phenotypic spectrum of PXE.
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Affiliation(s)
- Q Li
- Department of Dermatology and Cutaneous Biology, Jefferson Medical College and Jefferson Institute of Molecular Medicine, Thomas Jefferson University, 233 South 10th Street, Suite 450 BLSB, Philadelphia, PA, 19107, U.S.A
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29
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Jansen RS, Duijst S, Mahakena S, Sommer D, Szeri F, Váradi A, Plomp A, Bergen AA, Oude Elferink RPJ, Borst P, van de Wetering K. ABCC6-mediated ATP secretion by the liver is the main source of the mineralization inhibitor inorganic pyrophosphate in the systemic circulation-brief report. Arterioscler Thromb Vasc Biol 2014; 34:1985-9. [PMID: 24969777 DOI: 10.1161/atvbaha.114.304017] [Citation(s) in RCA: 222] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
OBJECTIVE Mutations in ABCC6 underlie the ectopic mineralization disorder pseudoxanthoma elasticum (PXE) and some forms of generalized arterial calcification of infancy, both of which affect the cardiovascular system. Using cultured cells, we recently showed that ATP-binding cassette subfamily C member 6 (ABCC6) mediates the cellular release of ATP, which is extracellularly rapidly converted into AMP and the mineralization inhibitor inorganic pyrophosphate (PPi). The current study was performed to determine which tissues release ATP in an ABCC6-dependent manner in vivo, where released ATP is converted into AMP and PPi, and whether human PXE ptients have low plasma PPi concentrations. APPROACH AND RESULTS Using cultured primary hepatocytes and in vivo liver perfusion experiments, we found that ABCC6 mediates the direct, sinusoidal, release of ATP from the liver. Outside hepatocytes, but still within the liver vasculature, released ATP is converted into AMP and PPi. The absence of functional ABCC6 in patients with PXE leads to strongly reduced plasma PPi concentrations. CONCLUSIONS Hepatic ABCC6-mediated ATP release is the main source of circulating PPi, revealing an unanticipated role of the liver in systemic PPi homeostasis. Patients with PXE have a strongly reduced plasma PPi level, explaining their mineralization disorder. Our results indicate that systemic PPi is relatively stable and that PXE, generalized arterial calcification of infancy, and other ectopic mineralization disorders could be treated with PPi supplementation therapy.
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Affiliation(s)
- Robert S Jansen
- From the Division of Molecular Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands (R.S.J., S.M., D.S., P.B., K.v.d.W.); Tytgat Institute for Liver and Intestinal Research, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands (S.D., R.P.J.O.E.); Institute of Enzymology, RCNS, Hungarian Academy of Sciences, Budapest, Hungary (F.S., A.V.); Department of Clinical Genetics, Academic Medical Center, Amsterdam, The Netherlands (A.P., A.A.B.); and Netherlands Institute for Neuroscience, Amsterdam, The Netherlands (A.A.B.)
| | - Suzanne Duijst
- From the Division of Molecular Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands (R.S.J., S.M., D.S., P.B., K.v.d.W.); Tytgat Institute for Liver and Intestinal Research, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands (S.D., R.P.J.O.E.); Institute of Enzymology, RCNS, Hungarian Academy of Sciences, Budapest, Hungary (F.S., A.V.); Department of Clinical Genetics, Academic Medical Center, Amsterdam, The Netherlands (A.P., A.A.B.); and Netherlands Institute for Neuroscience, Amsterdam, The Netherlands (A.A.B.)
| | - Sunny Mahakena
- From the Division of Molecular Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands (R.S.J., S.M., D.S., P.B., K.v.d.W.); Tytgat Institute for Liver and Intestinal Research, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands (S.D., R.P.J.O.E.); Institute of Enzymology, RCNS, Hungarian Academy of Sciences, Budapest, Hungary (F.S., A.V.); Department of Clinical Genetics, Academic Medical Center, Amsterdam, The Netherlands (A.P., A.A.B.); and Netherlands Institute for Neuroscience, Amsterdam, The Netherlands (A.A.B.)
| | - Daniela Sommer
- From the Division of Molecular Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands (R.S.J., S.M., D.S., P.B., K.v.d.W.); Tytgat Institute for Liver and Intestinal Research, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands (S.D., R.P.J.O.E.); Institute of Enzymology, RCNS, Hungarian Academy of Sciences, Budapest, Hungary (F.S., A.V.); Department of Clinical Genetics, Academic Medical Center, Amsterdam, The Netherlands (A.P., A.A.B.); and Netherlands Institute for Neuroscience, Amsterdam, The Netherlands (A.A.B.)
| | - Flóra Szeri
- From the Division of Molecular Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands (R.S.J., S.M., D.S., P.B., K.v.d.W.); Tytgat Institute for Liver and Intestinal Research, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands (S.D., R.P.J.O.E.); Institute of Enzymology, RCNS, Hungarian Academy of Sciences, Budapest, Hungary (F.S., A.V.); Department of Clinical Genetics, Academic Medical Center, Amsterdam, The Netherlands (A.P., A.A.B.); and Netherlands Institute for Neuroscience, Amsterdam, The Netherlands (A.A.B.)
| | - András Váradi
- From the Division of Molecular Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands (R.S.J., S.M., D.S., P.B., K.v.d.W.); Tytgat Institute for Liver and Intestinal Research, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands (S.D., R.P.J.O.E.); Institute of Enzymology, RCNS, Hungarian Academy of Sciences, Budapest, Hungary (F.S., A.V.); Department of Clinical Genetics, Academic Medical Center, Amsterdam, The Netherlands (A.P., A.A.B.); and Netherlands Institute for Neuroscience, Amsterdam, The Netherlands (A.A.B.)
| | - Astrid Plomp
- From the Division of Molecular Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands (R.S.J., S.M., D.S., P.B., K.v.d.W.); Tytgat Institute for Liver and Intestinal Research, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands (S.D., R.P.J.O.E.); Institute of Enzymology, RCNS, Hungarian Academy of Sciences, Budapest, Hungary (F.S., A.V.); Department of Clinical Genetics, Academic Medical Center, Amsterdam, The Netherlands (A.P., A.A.B.); and Netherlands Institute for Neuroscience, Amsterdam, The Netherlands (A.A.B.)
| | - Arthur A Bergen
- From the Division of Molecular Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands (R.S.J., S.M., D.S., P.B., K.v.d.W.); Tytgat Institute for Liver and Intestinal Research, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands (S.D., R.P.J.O.E.); Institute of Enzymology, RCNS, Hungarian Academy of Sciences, Budapest, Hungary (F.S., A.V.); Department of Clinical Genetics, Academic Medical Center, Amsterdam, The Netherlands (A.P., A.A.B.); and Netherlands Institute for Neuroscience, Amsterdam, The Netherlands (A.A.B.)
| | - Ronald P J Oude Elferink
- From the Division of Molecular Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands (R.S.J., S.M., D.S., P.B., K.v.d.W.); Tytgat Institute for Liver and Intestinal Research, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands (S.D., R.P.J.O.E.); Institute of Enzymology, RCNS, Hungarian Academy of Sciences, Budapest, Hungary (F.S., A.V.); Department of Clinical Genetics, Academic Medical Center, Amsterdam, The Netherlands (A.P., A.A.B.); and Netherlands Institute for Neuroscience, Amsterdam, The Netherlands (A.A.B.)
| | - Piet Borst
- From the Division of Molecular Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands (R.S.J., S.M., D.S., P.B., K.v.d.W.); Tytgat Institute for Liver and Intestinal Research, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands (S.D., R.P.J.O.E.); Institute of Enzymology, RCNS, Hungarian Academy of Sciences, Budapest, Hungary (F.S., A.V.); Department of Clinical Genetics, Academic Medical Center, Amsterdam, The Netherlands (A.P., A.A.B.); and Netherlands Institute for Neuroscience, Amsterdam, The Netherlands (A.A.B.)
| | - Koen van de Wetering
- From the Division of Molecular Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands (R.S.J., S.M., D.S., P.B., K.v.d.W.); Tytgat Institute for Liver and Intestinal Research, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands (S.D., R.P.J.O.E.); Institute of Enzymology, RCNS, Hungarian Academy of Sciences, Budapest, Hungary (F.S., A.V.); Department of Clinical Genetics, Academic Medical Center, Amsterdam, The Netherlands (A.P., A.A.B.); and Netherlands Institute for Neuroscience, Amsterdam, The Netherlands (A.A.B.).
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Genetic modulation of nephrocalcinosis in mouse models of ectopic mineralization: the Abcc6(tm1Jfk) and Enpp1(asj) mutant mice. J Transl Med 2014; 94:623-32. [PMID: 24732453 PMCID: PMC4039617 DOI: 10.1038/labinvest.2014.52] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 02/12/2014] [Accepted: 02/27/2014] [Indexed: 11/09/2022] Open
Abstract
Ectopic mineralization of renal tissues in nephrocalcinosis is a complex, multifactorial process. The purpose of this study was to examine the role of genetic modulation and the role of diet in nephrocalcinosis using two established mouse models of ectopic mineralization, Abcc6(tm1Jfk) and Enpp1(asj) mice, which serve as models for pseudoxanthoma elasticum and generalized arterial calcification of infancy, two heritable disorders, respectively. These mutant mice, when on standard rodent diet, develop nephrocalcinosis only at a very late age. In contrast, when placed on an 'acceleration diet' composed of increased phosphate and reduced magnesium content, they showed extensive mineralization of the kidneys affecting primarily the medullary tubules as well as arcuate and renal arteries, as examined by histopathology and quantitated by chemical assay for calcium. Mineralization could also be detected noninvasively by micro computed tomography. Whereas the heterozygous mice did not develop nephrocalcinosis, compound heterozygous mice carrying both mutant alleles, Abcc6(tm1Jfk/+) and Enpp1(+/asj), developed ectopic mineralization similar to that noted in homozygous mice for either gene, indicating that deletion of one Abcc6 allele along with Enpp1 haploinsufficiency resulted in renal mineralization. Thus, synergistic genetic defects in the complex mineralization/antimineralization network can profoundly modulate the degree of ectopic mineralization in nephrocalcinosis.
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Hosen MJ, Coucke PJ, Le Saux O, De Paepe A, Vanakker OM. Perturbation of specific pro-mineralizing signalling pathways in human and murine pseudoxanthoma elasticum. Orphanet J Rare Dis 2014; 9:66. [PMID: 24775865 PMCID: PMC4022264 DOI: 10.1186/1750-1172-9-66] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Accepted: 04/14/2014] [Indexed: 01/26/2023] Open
Abstract
Background Pseudoxanthoma elasticum (PXE) is characterized by skin (papular lesions), ocular (subretinal neovascularisation) and cardiovascular manifestations (peripheral artery disease), due to mineralization and fragmentation of elastic fibres in the extracellular matrix (ECM). Caused by mutations in the ABCC6 gene, the mechanisms underlying this disease remain unknown. The knowledge on the molecular background of soft tissue mineralization largely comes from insights in vascular calcification, with involvement of the osteoinductive Transforming Growth Factor beta (TGFβ) family (TGFβ1-3 and Bone Morphogenetic Proteins [BMP]), together with ectonucleotides (ENPP1), Wnt signalling and a variety of local and systemic calcification inhibitors. In this study, we have investigated the relevance of the signalling pathways described in vascular soft tissue mineralization in the PXE knock-out mouse model and in PXE patients. Methods The role of the pro-osteogenic pathways BMP2-SMADs-RUNX2, TGFβ-SMAD2/3 and Wnt-MSX2, apoptosis and ER stress was evaluated using immunohistochemistry, mRNA expression profiling and immune-co-staining in dermal tissues and fibroblast cultures of PXE patients and the eyes and whiskers of the PXE knock-out mouse. Apoptosis was further evaluated by TUNEL staining and siRNA mediated gene knockdown. ALPL activity in PXE fibroblasts was studied using ALPL stains. Results We demonstrate the upregulation of the BMP2-SMADs-RUNX2 and TGFβ-2-SMAD2/3 pathway, co-localizing with the mineralization sites, and the involvement of MSX2-canonical Wnt signalling. Further, we show that apoptosis is also involved in PXE with activation of Caspases and BCL-2. In contrast to vascular calcification, neither the other BMPs and TGFβs nor endoplasmic reticulum stress pathways seem to be perturbed in PXE. Conclusions Our study shows that we cannot simply extrapolate knowledge on cell signalling in vascular soft tissue calcification to a multisystem ectopic mineralisation disease as PXE. Contrary, we demonstrate a specific set of perturbed signalling pathways in PXE patients and the knock-out mouse model. Based on our findings and previously reported data, we propose a preliminary cell model of ECM calcification in PXE.
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Uitto J, Jiang Q, Váradi A, Bercovitch LG, Terry SF. PSEUDOXANTHOMA ELASTICUM: DIAGNOSTIC FEATURES, CLASSIFICATION, AND TREATMENT OPTIONS. Expert Opin Orphan Drugs 2014; 2:567-577. [PMID: 25383264 DOI: 10.1517/21678707.2014.908702] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
INTRODUCTION Pseudoxanthoma elasticum (PXE), a multisystem orphan disease, clinically affects the skin, the eyes, and the cardiovascular system with considerable morbidity and mortality. The clinical manifestations reflect the underlying pathology consisting of ectopic mineralization of peripheral connective tissues. AREAS COVERED The diagnostic criteria of PXE include characteristic clinical findings, together with histopathology of accumulation of pleiomorphic elastic structures in the dermis with progressive mineralization, and the presence of mutations in the ABCC6 gene. PXE-like cutaneous changes can also be encountered in other ectopic mineralization disorders, including generalized arterial calcification of infancy (GACI) caused by mutations in the ENPP1 gene. In some cases, overlapping clinical features of PXE/GACI, associated with mutations either in ABCC6 or ENPP1, have been noted. PXE demonstrates considerable inter- and intrafamilial heterogeneity, and consequently, accurate diagnosis is required for appropriate classification with prognostic implications. There is no effective and specific treatment for the systemic manifestations of PXE, but effective therapies to counteract the ocular complications are in current clinical use. EXPERT OPINION A number of observations in the murine model, the Abcc6-/- mouse, have indicated that the mineral composition of diet, particularly the magnesium content, can influence the severity of the mineralization phenotype. These observations suggest that appropriate dietary interventions, coupled with lifestyle modifications, including smoking cessation, might alleviate the symptoms and improve the quality of life of individuals affected with this, currently intractable, orphan disease.
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Affiliation(s)
- Jouni Uitto
- Department of Dermatology and Cutaneous Biology, Jefferson Medical College, Philadelphia, PA
| | - Qiujie Jiang
- Department of Dermatology and Cutaneous Biology, Jefferson Medical College, Philadelphia, PA
| | - András Váradi
- Institute of Enzymology, RCNS, Hungarian Academy of Sciences
| | - Lionel G Bercovitch
- Department of Dermatology, Warren Alpert Medical School of Brown University, Providence, RI ; PXE International, Washington, DC
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Li Q, Brodsky JL, Conlin LK, Pawel B, Glatz AC, Gafni RI, Schurgers L, Uitto J, Hakonarson H, Deardorff MA, Levine MA. Mutations in the ABCC6 gene as a cause of generalized arterial calcification of infancy: genotypic overlap with pseudoxanthoma elasticum. J Invest Dermatol 2014; 134:658-665. [PMID: 24008425 PMCID: PMC3945730 DOI: 10.1038/jid.2013.370] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Revised: 07/16/2013] [Accepted: 08/06/2013] [Indexed: 02/07/2023]
Abstract
Generalized arterial calcification of infancy (GACI) is an autosomal recessive disorder characterized by congenital calcification of large- and medium-sized arteries, associated with early myocardial infarction, heart failure, and stroke, and premature death. Most cases of GACI are caused by mutations in the ENPP1 gene. We first studied two siblings with GACI from a non-consanguineous family without mutations in the ENPP1 gene. To search for disease-causing mutations, we identified genomic regions shared between the two affected siblings but not their unaffected parents or brother. The ABCC6 gene, which is mutated in pseudoxanthoma elasticum (PXE), resided within a small region of homozygosity shared by the affected siblings. Sequence analysis of ABCC6 revealed that the two affected siblings were homozygous for the missense mutation p.R1314W. Subsequently, ABCC6 mutations were identified in five additional GACI families with normal ENPP1 sequences. Genetic mutations in ABCC6 in patients with PXE are associated with ectopic tissue mineralization in the skin and arterial blood vessels. Thus, our findings provide additional evidence that the ABCC6 gene product inhibits calcification under physiologic conditions and confirm a second locus for GACI. In addition, our study emphasizes the potential utility of shared homozygosity mapping to identify genetic causes of inherited disorders.
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Affiliation(s)
- Qiaoli Li
- Departments of Dermatology and Cutaneous Biology, and Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Jill L Brodsky
- Division of Endocrinology and Diabetes, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA; Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Laura K Conlin
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, USA
| | - Bruce Pawel
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, USA
| | - Andrew C Glatz
- Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA; Division of Cardiology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Rachel I Gafni
- National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland, USA
| | - Leon Schurgers
- Department of Biochemistry, Cardiovascular Research Institute, University of Maastricht, Maastricht, The Netherlands
| | - Jouni Uitto
- Departments of Dermatology and Cutaneous Biology, and Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Hakon Hakonarson
- Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA; Division of Genetics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Matthew A Deardorff
- Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA; Division of Genetics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Michael A Levine
- Division of Endocrinology and Diabetes, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA; Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA.
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Li Q, Guo H, Chou DW, Berndt A, Sundberg JP, Uitto J. Mouse models for pseudoxanthoma elasticum: genetic and dietary modulation of the ectopic mineralization phenotypes. PLoS One 2014; 9:e89268. [PMID: 24586646 PMCID: PMC3929712 DOI: 10.1371/journal.pone.0089268] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Accepted: 01/17/2014] [Indexed: 11/25/2022] Open
Abstract
Pseudoxanthoma elasticum (PXE), a heritable ectopic mineralization disorder, is caused by mutations in the ABCC6 gene. Null mice (Abcc6−/−) recapitulate the genetic, histopathologic and ultrastructural features of PXE, and they demonstrate early and progressive mineralization of vibrissae dermal sheath, which serves as a biomarker of the overall mineralization process. Recently, as part of a mouse aging study at The Jackson Laboratory, 31 inbred mouse strains were necropsied, and two of them, KK/HlJ and 129S1/SvImJ, were noted to have vibrissae dermal mineralization similar to Abcc6−/− mice. These two strains were shown to harbor a single nucleotide polymorphism (rs32756904) in the Abcc6 gene, which resulted in out-of-frame splicing and marked reduction in ABCC6 protein expression in the liver of these mice. The same polymorphism is present in two additional mouse strains, DBA/2J and C3H/HeJ, with similar reduction in Abcc6 protein levels, yet these mice did not demonstrate tissue mineralization when kept on standard rodent diet. However, all four mouse strains, when placed on experimental diet enriched in phosphate and low in magnesium, developed extensive ectopic mineralization. These results indicate that the genetic background of mice and the mineral composition of their diet can profoundly modulate the ectopic mineralization process predicated on mutations in the Abcc6 gene. These mice provide novel model systems to study the pathomechanisms and the reasons for strain background on phenotypic variability of PXE.
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Affiliation(s)
- Qiaoli Li
- Department of Dermatology and Cutaneous Biology, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Haitao Guo
- Department of Dermatology and Cutaneous Biology, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - David W. Chou
- Department of Dermatology and Cutaneous Biology, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Annerose Berndt
- Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - John P. Sundberg
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
| | - Jouni Uitto
- Department of Dermatology and Cutaneous Biology, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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ABCC6 prevents ectopic mineralization seen in pseudoxanthoma elasticum by inducing cellular nucleotide release. Proc Natl Acad Sci U S A 2013; 110:20206-11. [PMID: 24277820 DOI: 10.1073/pnas.1319582110] [Citation(s) in RCA: 193] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Pseudoxanthoma elasticum (PXE) is an autosomal recessive disease characterized by progressive ectopic mineralization of the skin, eyes, and arteries, for which no effective treatment exists. PXE is caused by inactivating mutations in the gene encoding ATP-binding cassette sub-family C member 6 (ABCC6), an ATP-dependent efflux transporter present mainly in the liver. Abcc6(-/-) mice have been instrumental in demonstrating that PXE is a metabolic disease caused by the absence of an unknown factor in the circulation, the presence of which depends on ABCC6 in the liver. Why absence of this factor results in PXE has remained a mystery. Here we report that medium from HEK293 cells overexpressing either human or rat ABCC6 potently inhibits mineralization in vitro, whereas medium from HEK293 control cells does not. Untargeted metabolomics revealed that cells expressing ABCC6 excrete large amounts of nucleoside triphosphates, even though ABCC6 itself does not transport nucleoside triphosphates. Extracellularly, ectonucleotidases hydrolyze the excreted nucleoside triphosphates to nucleoside monophosphates and inorganic pyrophosphate (PPi), a strong inhibitor of mineralization that plays a pivotal role in several mineralization disorders similar to PXE. The in vivo relevance of our data are demonstrated in Abcc6(-/-) mice, which had plasma PPi levels <40% of those found in WT mice. This study provides insight into how ABCC6 affects PXE. Our data indicate that the factor that normally prevents PXE is PPi, which is provided to the circulation in the form of nucleoside triphosphates via an as-yet unidentified but ABCC6-dependent mechanism.
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Li Q, Jiang Q, Uitto J. Ectopic mineralization disorders of the extracellular matrix of connective tissue: molecular genetics and pathomechanisms of aberrant calcification. Matrix Biol 2013; 33:23-8. [PMID: 23891698 DOI: 10.1016/j.matbio.2013.06.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Revised: 06/10/2013] [Accepted: 06/11/2013] [Indexed: 01/07/2023]
Abstract
Ectopic mineralization of connective tissues is a complex process leading to deposition of calcium phosphate complexes in the extracellular matrix, particularly affecting the skin and the arterial blood vessels and common in age-associated disorders. A number of initiating and contributing metabolic and environmental factors are linked to aberrant mineralization in these diseases, making the identification of precise pathomechanistic pathways exceedingly difficult. However, there has been significant recent progress in understanding the ectopic mineralization processes through study of heritable single-gene disorders, which have allowed identification of discrete pathways and contributing factors leading to aberrant connective tissue mineralization. These studies have provided support for the concept of an intricate mineralization/anti-mineralization network present in peripheral connective tissues, providing a perspective to development of pharmacologic approaches to limit the phenotypic consequences of ectopic mineralization. This overview summarizes the current knowledge of ectopic heritable mineralization disorders, with accompanying animal models, focusing on pseudoxanthoma elasticum and generalized arterial calcification of infancy, two autosomal recessive diseases manifesting with extensive connective tissue mineralization in the skin and the cardiovascular system.
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Affiliation(s)
- Qiaoli Li
- Department of Dermatology and Cutaneous Biology, Jefferson Medical College, 233 S. 10th Street, Philadelphia, PA, United States
| | - Qiujie Jiang
- Department of Dermatology and Cutaneous Biology, Jefferson Medical College, 233 S. 10th Street, Philadelphia, PA, United States
| | - Jouni Uitto
- Department of Dermatology and Cutaneous Biology, Jefferson Medical College, 233 S. 10th Street, Philadelphia, PA, United States.
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Li Q, Uitto J. Mineralization/anti-mineralization networks in the skin and vascular connective tissues. THE AMERICAN JOURNAL OF PATHOLOGY 2013; 183:10-8. [PMID: 23665350 PMCID: PMC3702739 DOI: 10.1016/j.ajpath.2013.03.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Accepted: 03/12/2013] [Indexed: 02/06/2023]
Abstract
Ectopic mineralization has been linked to several common clinical conditions with considerable morbidity and mortality. The mineralization processes, both metastatic and dystrophic, affect the skin and vascular connective tissues. There are several contributing metabolic and environmental factors that make uncovering of the precise pathomechanisms of these acquired disorders exceedingly difficult. Several relatively rare heritable disorders share phenotypic manifestations similar to those in common conditions, and, consequently, they serve as genetically controlled model systems to study the details of the mineralization process in peripheral tissues. This overview will highlight diseases with mineral deposition in the skin and vascular connective tissues, as exemplified by familial tumoral calcinosis, pseudoxanthoma elasticum, generalized arterial calcification of infancy, and arterial calcification due to CD73 deficiency. These diseases, and their corresponding mouse models, provide insight into the pathomechanisms of soft tissue mineralization and point to the existence of intricate mineralization/anti-mineralization networks in these tissues. This information is critical for understanding the pathomechanistic details of different mineralization disorders, and it has provided the perspective to develop pharmacological approaches to counteract the consequences of ectopic mineralization.
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Affiliation(s)
| | - Jouni Uitto
- Department of Dermatology and Cutaneous Biology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania
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Guo H, Li Q, Chou DW, Uitto J. Atorvastatin counteracts aberrant soft tissue mineralization in a mouse model of pseudoxanthoma elasticum (Abcc6⁻/⁻). J Mol Med (Berl) 2013; 91:1177-84. [PMID: 23807484 DOI: 10.1007/s00109-013-1066-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Revised: 06/04/2013] [Accepted: 06/10/2013] [Indexed: 01/07/2023]
Abstract
UNLABELLED Pseudoxanthoma elasticum (PXE), a multisystem heritable disorder with aberrant mineralization of arterial blood vessels, is caused by mutations in the ABCC6 gene. Previous studies have suggested that carriers of the ABCC6 mutations, particularly of p.R1141X, are at increased risk for coronary artery disease. In this study, we used Abcc6 (tm1Jfk) knock-out mice to determine the serum lipid profiles and examine the effects of atorvastatin on the aberrant mineralization in this model of PXE. First, serum lipid profiles at 12 weeks of age, after overnight fasting, revealed a statistically significant increase in total cholesterol and triglyceride levels in Abcc6 (tm1Jfk) mice compared to their wild-type littermates. Placing these mice at 4 weeks of age for 20 weeks on atorvastatin, either 0.01 % or 0.04 % of the diet (low statin and high statin groups, respectively), reduced the total triglyceride and cholesterol levels, which was accompanied with significantly reduced mineralization of the dermal sheath of vibrissae, a biomarker of the aberrant mineralization process in these mice. However, if the mice were placed on atorvastatin for 12 weeks at 12 weeks of age, at which time point significant mineralization had already taken place, no difference in the amount of mineralization was noted. These observations suggest that statins, particularly atorvastatin, can prevent, but not reverse, aberrant mineralization in this mouse model of PXE. For a clinical perspective, a survey of 1,747 patients with PXE was conducted regarding their present or past use of statins. The results indicated that about one third of all PXE patients are currently or have previously been on cholesterol-lowering drugs. Thus, a sizable number of patients with PXE could be subject to modulation of their mineralization processes by concomitant statin treatment. KEY MESSAGE The Abcc6 (-/-) mice serve as a model system for PXE, an ectopic mineralization disorder Abcc6 (-/-) mice were shown to have elevated serum cholesterol and triglyceride levels Feeding of the Abcc6 (-/-) mice with atorvastatin prevented connective tissue mineralization A third of patients with PXE was found to be on cholesterol-lowering therapy Atorvastatin may potentially be beneficial for patients with PXE.
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Affiliation(s)
- Haitao Guo
- Departments of Dermatology and Cutaneous Biology, and Biochemistry and Molecular Biology, Jefferson Medical College, and Jefferson Institute of Molecular Medicine, Thomas Jefferson University, 233 South 10th Street, Suite 450 BLSB, Philadelphia, PA, 19107, USA
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Premature termination codon read-through in the ABCC6 gene: potential treatment for pseudoxanthoma elasticum. J Invest Dermatol 2013; 133:2672-2677. [PMID: 23702584 PMCID: PMC3800235 DOI: 10.1038/jid.2013.234] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Revised: 04/17/2013] [Accepted: 04/27/2013] [Indexed: 12/16/2022]
Abstract
Pseudoxanthoma elasticum (PXE) is an autosomal recessive disorder manifesting with ectopic connective tissue mineralization, caused by mutations in the ABCC6 gene, with ~35% of all mutations being premature termination mutations. In this study, we investigated the therapeutic potential of the nonsense codon read-through-inducing drug, PTC124, in treating PXE. The ability of this drug to facilitate read-through of nonsense mutations was examined in HEK293 cells transfected with human ABCC6 expression constructs harboring seven different PXE-associated nonsense mutations, and was evaluated by immunofluorescence and In-Cell ELISA. Our data demonstrated that PTC124 did not exhibit cytotoxicity in concentrations up to 20 μg ml(-1), and the facilitated read-through varied not only with dose but also with sequence context. Considering the redundancy of the genetic code, it was postulated that in case of the most common recurrent nonsense mutation, p.R1141X, the read-through may result in substitution of the arginine 1,141 by glycine, tryptophan, or cysteine. Their potential pathogenicity was tested in a recently developed zebrafish messenger RNA (mRNA) rescue assay, and demonstrated that all three mRNA transcripts were able to rescue abcc6a morpholino-induced phenotype of zebrafish. Thus, our results suggest that read-through of nonsense mutations in ABCC6 by PTC124 may have potential for pharmacologic treatment of PXE.
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