[show abstract][hide abstract] ABSTRACT: In this study, 103 unrelated South-American patients with mucopolysaccharidosis type II (MPS II) were investigated aiming at the identification of iduronate-2-sulfatase (IDS) disease causing mutations and the possibility of some insights on the genotype-phenotype correlation The strategy used for genotyping involved the identification of the previously reported inversion/disruption of the IDS gene by PCR and screening for other mutations by PCR/SSCP. The exons with altered mobility on SSCP were sequenced, as well as all the exons of patients with no SSCP alteration. By using this strategy, we were able to find the pathogenic mutation in all patients. Alterations such as inversion/disruption and partial/total deletions of the IDS gene were found in 20/103 (19%) patients. Small insertions/deletions/indels (<22bp) and point mutations were identified in 83/103 (88%) patients, including 30 novel mutations; except for a higher frequency of small duplications in relation to small deletions, the frequencies of major and minor alterations found in our sample are in accordance with those described in the literature.
Molecular Genetics and Metabolism 09/2013; · 2.83 Impact Factor
[show abstract][hide abstract] ABSTRACT: In this study we investigate whether Amphotericin B (AmB), a widely used antifungal agent, could decrease the proliferation of a myofibroblast cell line - GRX, a model of activated hepatic stellate cells (HSC). Three different hepatic cell lines (GRX, Hep G2 and ARL-6) were treated with two concentrations of AmB (1.25 μg/mL or 2.50 μg/ml). Cytotoxicity was assessed by MTT assay. The effects of AmB on GRX migration was evaluated by Wound-healing Assay. Cell cycle arrest was investigated by flow cytometry. Apoptosis and autophagy were analyzed by Caspase 3 and LC3 imunnostaining, respectively. Treatment with AmB 1.25 or 2.50 μg/ml showed a decrease in viability of GRX cells. This decrease was not observed for Hep G2 or ARL-6 in any of the two AmB concentrations tested. GRX cells treated with 1.25 μg/ml AmB were unable to close the wound after 96 hours. Cell cycle analysis showed an increase in sub-G1 population and a decrease in G2/M population in AmB-treated cells. In addition, AmB-treated GRX cells showed increased expression of LC-3 and Caspase-3 by immunohistochemistry, suggesting an increase in both autophagy and apoptosis. Here we show that AmB is cytotoxic for GRX cells, a model of activated HSC, but not for hepatic lineages HepG2 and ARL6.
[show abstract][hide abstract] ABSTRACT: Using a clinical survey, panoramic, cone-beam computed tomography (CBCT), and magnetic resonance (MR) imaging, this study was conducted to ascertain primary maxillofacial abnormalities in patients with mucopolysaccharidosis VI (MPS VI).
Two patients previously diagnosed with MPS VI underwent clinical and imaging surveys (panoramic radiographs, CBCT, and MR imaging).
Jaw involvement was present in all patients. The most prevalent findings were enlarged marrow spaces, osteopenia, dentigerous cyst-like follicles, effacement of the jaw structures, and osteosclerosis. This is the first study to describe temporomandibular joint (TMJ) involvement for MPS VI.
CBCT and MR imaging were needed to observe features that were not clear in conventional radiographs. Both patients reported symptoms in the TMJ and demonstrated involvement during their examinations. A multicenter study is necessary to better document maxillofacial involvement in MPS VI.
[show abstract][hide abstract] ABSTRACT: Mucopolysaccharidosis VII (MPS VII) is due to the deficient activity of β-glucuronidase (GUSB) and results in the accumulation of glycosaminoglycans (GAGs) in lysosomes and multisystemic disease with cardiovascular manifestations. The goal here was to determine the pathogenesis of mitral valve (MV) disease in MPS VII dogs. Untreated MPS VII dogs had a marked reduction in the histochemical signal for structurally-intact collagen in the MV at 6months of age, when mitral regurgitation had developed. Electron microscopy demonstrated that collagen fibrils were of normal diameter, but failed to align into large parallel arrays. mRNA analysis demonstrated a modest reduction in the expression of genes that encode collagen or collagen-associated proteins such as the proteoglycan decorin which helps collagen fibrils assemble, and a marked increase for genes that encode proteases such as cathepsins. Indeed, enzyme activity for cathepsin B (CtsB) was 19-fold normal. MPS VII dogs that received neonatal intravenous injection of a gamma retroviral vector had an improved signal for structurally-intact collagen, and reduced CtsB activity relative to that seen in untreated MPS VII dogs. We conclude that MR in untreated MPS VII dogs was likely due to abnormalities in MV collagen structure. This could be due to upregulation of enzymes that degrade collagen or collagen-associated proteins, to the accumulation of GAGs that compete with proteoglycans such as decorin for binding to collagen, or to other causes. Further delineation of the etiology of abnormal collagen structure may lead to treatments that improve biomechanical properties of the MV and other tissues.
Molecular Genetics and Metabolism 06/2013; · 2.83 Impact Factor
[show abstract][hide abstract] ABSTRACT: Mucopolysaccharidoses (MPS) are lysosomal storage disorders characterized by mutations in enzymes that degrade glycosaminoglycans (GAGs). Joint disease is present in most forms of MPS, including MPS I. This work aimed to describe the joint disease progression in the murine model of MPS I. Normal (wild-type) and MPS I mice were sacrificed at different time points (from 2 to 12 months). The knee joints were collected, and haematoxylin-eosin staining was used to evaluate the articular architecture. Safranin-O and Sirius Red staining was used to analyse the proteoglycan and collagen content. Additionally, we analysed the expression of the matrix-degrading metalloproteinases (MMPs), MMP-2 and MMP-9, using immunohistochemistry. We observed progressive joint alterations from 6 months, including the presence of synovial inflammatory infiltrate, the destruction and thickening of the cartilage extracellular matrix, as well as proteoglycan and collagen depletion. Furthermore, we observed an increase in the expression of MMP-2 and MMP-9, which could conceivably explain the degenerative changes. Our results suggest that the joint disease in MPS I mice may be caused by a degenerative process due to increase in proteases expression, leading to loss of collagen and proteoglycans. These results may guide the development of ancillary therapies for joint disease in MPS I.
International Journal of Experimental Pathology 06/2013; · 2.04 Impact Factor
[show abstract][hide abstract] ABSTRACT: Hunter Disease or mucopolysaccharidosis type II (MPS II) is an X-linked recessive lysosomal disorder caused by the deficit of the enzyme iduronate-2-sulfatase (IDS), involved in the catabolism of the glycosaminoglycans heparan and dermatan sulphate. Our aim was to search for molecular defects in the promoter region of the IDS gene in patients with previous biochemical diagnosis of MPS II and after we sequenced the whole IDS coding region and the exon/intron boundaries without detecting any pathogenic mutations. Screening of the promoter region of four patients detected in two of them a 178bp deletion and in the other two a single nucleotide substitution 818bp upstream of the coding region. The latter had never been described before in MPS II patients and it turned out to be a polymorphism. Our experience suggests that MPS II patients with no mutations detected in the IDS coding region should be screened in the promoter region of the gene. Findings will hopefully help to clarify the relationship between genotype and phenotype and will be useful for the correct molecular diagnosis of Hunter patients and the identification of female carriers, the latter particularly important for genetic counseling.
[show abstract][hide abstract] ABSTRACT: Hunter syndrome (mucopolysaccharidosis type II) is a rare and life-limiting multisystemic disorder with an X-linked recessive pattern of inheritance. Short stature is a prominent feature of this condition. This analysis aimed to investigate the effects of enzyme replacement therapy with idursulfase on growth in patients enrolled in HOS — the Hunter Outcome Survey which is a multinational observational database. As of Jan 2012, height data before treatment were available for 567 of 740 males followed prospectively after HOS entry. Cross-sectional analysis showed that short stature became apparent after approximately 8 years of age; before this, height remained within the normal range. Age-corrected standardized height scores (z-scores) be-fore and after treatment were assessed using piecewise regression model analysis in 133 patients (8–15 years of age at treatment start; data available on ≥1 occasion within +/−24 months of treatment start; growth hormone-treated patients excluded). Results showed that the slope after treatment (slope = −0.005) was significantly improved compared with before treatment (slope = −0.043) (difference = 0.038, p = 0.004). Analysis of covariates (age at treatment start, cognitive involvement, presence of puberty at the start of ERT, mutation type, functional classification), showed a significant influence on growth of mutation type (height deficit in terms of z-scores most pronounced in patients with deletions/large rearrangements/nonsense mutations, p b 0.0001) and age (most pronounced in the 12–15-year group, p b 0.0001). Cognitive involvement, pubertal status at the start of ERT and functional classification were not related to the growth deficit or response to treatment. In conclusion, the data showed an improvement in growth rate in patients with Hunter syndrome following idursulfase treatment.
[show abstract][hide abstract] ABSTRACT: Since we previously observed that in patients with mucopolysaccharidosis (MPS) the storage of undegraded glycosaminoglycans (GAG) occurs from birth, in the present study we aimed to compare normal, untreated MPS I mice (knockout for alpha-l-iduronidase-IDUA), and MPS I mice treated with enzyme replacement therapy (ERT, Laronidase, 1.2mg/kg every 2weeks) started from birth (ERT-neo) or from 2months of age (ERT-ad). All mice were sacrificed at 6months. Both treatments were equally effective in normalizing GAG levels in the viscera but had no detectable effect on the joint. Heart function was also improved with both treatments. On the other hand, mice treated from birth presented better outcomes in the difficult-to-treat aortas and heart valves. Surprisingly, both groups had improvements in behavior tests, and normalization of GAG levels in the brain and IDUA injection resulted in detectable levels of enzyme in the brain tissue 1h after administration. ERT-ad mice developed significantly more anti-IDUA-IgG antibodies, and mice that didn't develop antibodies had better performances in behavior tests, indicating that development of antibodies may reduce enzyme bioavailability. Our results suggest that ERT started from birth leads to better outcomes in the aorta and heart valves, as well as a reduction in antibody levels. Some poor vascularized organs, such as the joints, had partial or no benefit and ancillary therapies might be needed for patients. The results presented here support the idea that ERT started from birth leads to better treatment outcomes and should be considered whenever possible, a observation that gains relevance as newborn screening programs are being considered for MPS and other treatable lysosomal storage disorders.
Molecular Genetics and Metabolism 03/2013; · 2.83 Impact Factor
[show abstract][hide abstract] ABSTRACT: Hunter syndrome (mucopolysaccharidosis type II) is a rare and life-limiting multisystemic disorder with an X-linked recessive pattern of inheritance. Short stature is a prominent feature of this condition. This analysis aimed to investigate the effects of enzyme replacement therapy with idursulfase on growth in patients enrolled in HOS - the Hunter Outcome Survey which is a multinational observational database. As of Jan 2012, height data before treatment were available for 567 of 740 males followed prospectively after HOS entry. Cross-sectional analysis showed that short stature became apparent after approximately 8years of age; before this, height remained within the normal range. Age-corrected standardized height scores (z-scores) before and after treatment were assessed using piecewise regression model analysis in 133 patients (8-15years of age at treatment start; data available on ≥1 occasion within +/-24months of treatment start; growth hormone-treated patients excluded). Results showed that the slope after treatment (slope=-0.005) was significantly improved compared with before treatment (slope=-0.043) (difference=0.038, p=0.004). Analysis of covariates (age at treatment start, cognitive involvement, presence of puberty at the start of ERT, mutation type, functional classification), showed a significant influence on growth of mutation type (height deficit in terms of z-scores most pronounced in patients with deletions/large rearrangements/nonsense mutations, p<0.0001) and age (most pronounced in the 12-15-year group, p<0.0001). Cognitive involvement, pubertal status at the start of ERT and functional classification were not related to the growth deficit or response to treatment. In conclusion, the data showed an improvement in growth rate in patients with Hunter syndrome following idursulfase treatment.
Molecular Genetics and Metabolism 03/2013; · 2.83 Impact Factor
[show abstract][hide abstract] ABSTRACT: Characteristic cardiac valve abnormalities and left ventricular hypertrophy are present in untreated patients with mucopolysaccharidosis type VI (MPS VI). Cardiac ultrasound was performed to investigate these findings in subjects during long-term enzyme replacement therapy (ERT) with recombi-nant human arylsulfatase B (rhASB, rhN-acetylgalactosamine 4-sulfatase, galsulfase, Naglazyme®). Studies were conducted in 54 subjects before ERT was begun and at specific intervals for up to 96 weeks of weekly infusions of rhASB at 1 mg/kg during phase 1/2, phase 2, and phase 3 trials of rhASB. At baseline, mitral and aortic valve obstruction was present and was significantly greater in those ≥12 years of age. Mild mitral and trace aortic regurgitation were present, the former being significantly greater in those <12 years. Left ventricular hy-pertrophy, with averaged z-scores ranging from 1.6–1. ≥12 years. After 96 weeks of ERT, ventricular septal hyper-trophy regressed in those <12 years. For those ≥12 years, septal hypertrophy was unchanged, and aortic regurgitation increased statistically but not physiologically. Obstructive gradients across mitral and aortic valves remained unchanged. The results suggest that long-term ERT is effective in reducing intraventricular septal hypertrophy and preventing progres-sion of cardiac valve abnormalities when administered to those <12 years of age.
[show abstract][hide abstract] ABSTRACT: Cell encapsulation, although a promising strategy to deliver therapeutic products, is hampered by immune response against biomaterials. The aim of this article is to assess the effect of prednisolone on enzyme release by microencapsulated cells implanted in vivo. Recombinant cells encapsulated were implanted in the peritoneum of wild-type mice and mucopolysaccharidosis (MPS) I mice, with or without prednisolone. Later, microcapsules were recovered for histological and enzyme analysis. Blood was collected from MPS I mice. All animals receiving prednisolone had a smaller inflammatory infiltrate. In vitro, prednisolone increased the amount of enzyme released from the recovered capsules, but this was not accompanied by an increase in the amount of circulating enzyme in vivo after 15 days. However, in 7 days, prednisolone significantly increased the amount of enzyme detected in the serum. Although prednisolone improved enzyme release in vitro and in vivo after 7 days, it was unable to maintain this effect for a longer period.
Journal of Microencapsulation 02/2013; · 1.57 Impact Factor
[show abstract][hide abstract] ABSTRACT: OBJECTIVES: The objectives of this study are to quantify endurance and respiratory function and better characterize spectrum of symptoms and biochemical abnormalities in mucopolysaccharidosis IVA subjects. METHODS: MorCAP was a multicenter, multinational, cross sectional study amended to be longitudinal in 2011. Each study visit required collection of medical history, clinical assessments, and keratan sulfate (KS) levels. RESULTS: Data from the first visit of 325 subjects (53% female) were available. Mean age was 14.5years. Mean±SD height z-scores were -5.6±3.1 as determined by the CDC growth charts. Mean±SD from the 6-minute-walk-test was 212.6±152.2m, revealing limitations in functional endurance testing, and 30.0±24.0stairs/min for the 3-minute-stair-climb test. Respiratory function showed limitations comparable to MPS VI patients; mean±SD was 1.2±0.9l based on forced vital capacity and 34.8±25.5l/min based on maximum voluntary ventilation. Mean urinary keratan sulfate (uKS) was elevated for all ages, and negatively correlated with age. Higher uKS correlated with greater clinical impairment based on height z-scores, endurance and respiratory function tests. The MPS Health Assessment Questionnaire reveals impairments in mobility and activities of daily living in comparison to an age-matched control population. CONCLUSIONS: MPS IVA is a multisystem disorder with a continuum of clinical presentation. All affected individuals experience significant functional limitations and reduced quality of life. Older patients have more severe exercise and respiratory capacity limitations, and more frequent cardiac pathology illustrating the progressive nature of disease.
Molecular Genetics and Metabolism 02/2013; · 2.83 Impact Factor
[show abstract][hide abstract] ABSTRACT: Diagnosis of lysosomal storage disorders (LSDs) is mainly based on specific enzyme assays in leucocytes. Dried blood spots have also been used as sample for the enzyme assays. However, some lysosomal enzymes such as heparan-N-sulfamidase (HNS) and others cannot be assayed by this material. We developed an assay for HNS using dried leukocytes impregnated in filter paper (DLFP) as source of enzyme, and the results allowed the correct identification of Mucopolisaccharidosis IIIA. From this proof of concept we predict that the assay of lysosomal enzymes in DLFP samples, which still needs further development, could be a useful tool for the diagnosis of LSDs, especially in regions where transportation of liquid blood samples in appropriate conditions for long distances and/or across country borders is challenging.
Molecular Genetics and Metabolism 02/2013; · 2.83 Impact Factor
[show abstract][hide abstract] ABSTRACT: Mucopolysaccharidosis IVA (MPS IVA; Morquio A syndrome) is an autosomal recessive lysosomal storage disorder resulting from a deficiency of N-acetylgalactosamine-6-sulfate sulfatase (GALNS) activity. Diagnosis can be challenging and requires agreement of clinical, radiographic, and laboratory findings. A group of biochemical genetics laboratory directors and clinicians involved in the diagnosis of MPS IVA, convened by BioMarin Pharmaceutical Inc., met to develop recommendations for diagnosis. The following conclusions were reached. Due to the wide variation and subtleties of radiographic findings, imaging of multiple body regions is recommended. Urinary glycosaminoglycan analysis is particularly problematic for MPS IVA and it is strongly recommended to proceed to enzyme activity testing even if urine appears normal when there is clinical suspicion of MPS IVA. Enzyme activity testing of GALNS is essential in diagnosing MPS IVA. Additional analyses to confirm sample integrity and rule out MPS IVB, multiple sulfatase deficiency, and mucolipidoses types II/III are critical as part of enzyme activity testing. Leukocytes or cultured dermal fibroblasts are strongly recommended for enzyme activity testing to confirm screening results. Molecular testing may also be used to confirm the diagnosis in many patients. However, two known or probable causative mutations may not be identified in all cases of MPS IVA. A diagnostic testing algorithm is presented which attempts to streamline this complex testing process.
Journal of Inherited Metabolic Disease 02/2013; · 4.07 Impact Factor