chondroitin-sulfates and Mucopolysaccharidosis-VI

The enzyme N-acetylgalactosamine-4-sulfatase (Arylsulfatase B; ARSB) was originally identified as a lysosomal enzyme which was deficient in Mucopolysaccharidosis VI (MPS VI; Maroteaux-Lamy Syndrome). The newly directed attention to the impact of ARSB in human pathobiology indicates a broader, more pervasive effect, encompassing roles as a tumor suppressor, transcriptional mediator, redox switch, and regulator of intracellular and extracellular-cell signaling. By controlling the degradation of chondroitin 4-sulfate and dermatan sulfate by removal or failure to remove the 4-sulfate residue at the non-reducing end of the sulfated glycosaminoglycan chain, ARSB modifies the binding or release of critical molecules into the cell milieu. These molecules, such as galectin-3 and SHP-2, in turn, influence crucial cellular processes and events which determine cell fate. Identification of ARSB at the cell membrane and in the nucleus expands perception of the potential impact of decline in ARSB activity. The regulation of availability of sulfate from chondroitin 4-sulfate and dermatan sulfate may also affect sulfate assimilation and production of vital molecules, including glutathione and cysteine. Increased attention to ARSB in mammalian cells may help to integrate and deepen our understanding of diverse biological phenomenon and to approach human diseases with new insights.

Topics: Chondroitin Sulfates; Dermatan Sulfate; Humans; Mucopolysaccharidosis VI; N-Acetylgalactosamine-4-Sulfatase; Sulfates

Mucopolysaccharidosis type VI, or Maroteaux-Lamy syndrome, is a rare, autosomal recessive genetic disease, mainly affecting the pediatric age group. The disease is due to pathogenic variants of the

Topics: Chondroitin Sulfates; Enzyme Replacement Therapy; Glycosaminoglycans; Humans; Mucopolysaccharidosis VI; N-Acetylgalactosamine-4-Sulfatase

Cystic fibrosis (CF) is associated with mutation and abnormal function of the cystic fibrosis transmembrane conductance regulator (CFTR) that affects cellular chloride transport. Clinically, CF of the lung is associated with excessive accumulation of secretions, including the sulfated glycosaminoglycans, chondroitin sulfate and dermatan sulfate (DS), both of which contain sulfated N-acetylgalactosamine residues. The sulfatase enzymes, which are a highly conserved group of enzymes with high specificity for designated sulfate groups, include arylsulfatase B, a lysosomal enzyme. Arylsulfatase B, also known as N-acetyl galactosamine 4-sulfatase, can degrade DS and chondroitin-4 sulfate. Previously reported data demonstrated diminished activity of arylsulfatase B in lymphoid cell lines of patients with CF compared to normal control subjects. Frequent infections with Pseudomonas, a sulfatase-producing organism, occur in patients with CF, whereas infections with Mycobacterium tuberculosis, which lacks sulfatase activity, are infrequent. Additional investigation to determine if diminished function of arylsulfatase B is a consistent finding in cells of patients with CF may be informative, and may help to correlate the molecular, biochemical, and clinical characteristics of CF.

Topics: Bacterial Infections; Chondroitin Sulfates; Cystic Fibrosis; Dermatan Sulfate; Glycosaminoglycans; Humans; Ion Exchange; Lung; Mucopolysaccharidosis VI; N-Acetylgalactosamine-4-Sulfatase; Pseudomonas Infections; Sodium; Sulfates; Tuberculosis

Topics: beta-Galactosidase; Cells, Cultured; Child, Preschool; Chondroitin Sulfates; Female; Fucose; Gangliosidoses; Genetic Carrier Screening; Hexosyltransferases; Humans; Iduronidase; Liver; Lysosomes; Mannose; Mucolipidoses; Mucopolysaccharidoses; Mucopolysaccharidosis I; Mucopolysaccharidosis II; Mucopolysaccharidosis III; Mucopolysaccharidosis IV; Mucopolysaccharidosis VI

We compared substrate reduction in patients with lysosomal storage disorder treated with hematopoietic stem cell transplant and found that it was significantly reduced compared with patients treated with pharmacological enzyme replacement therapy. These data might support the wider application of hematopoietic stem cell transplant in the treatment of lysosomal storage disorders.

Topics: Biomarkers; Chondroitin Sulfates; Dermatan Sulfate; Enzyme Therapy; Enzymes; Hematopoietic Stem Cell Transplantation; Humans; Mucopolysaccharidosis I; Mucopolysaccharidosis II; Mucopolysaccharidosis VI

Mucopolysaccharidoses are a class of lysosomal storage diseases, characterized by enzymatic deficiency in the degradation of specific glycosaminoglycans (GAG). Pathological accumulation of excess GAG leads to multiple clinical symptoms with systemic character, most severely affecting bones, muscles and connective tissues. Current therapies include periodic intravenous infusion of supplementary recombinant enzyme (Enzyme Replacement Therapy-ERT) or bone marrow transplantation. However, ERT has limited efficacy due to poor penetration in some organs and tissues. Here, we investigated the potential of the β-D-xyloside derivative odiparcil as an oral GAG clearance therapy for Maroteaux-Lamy syndrome (Mucopolysaccharidosis type VI, MPS VI). In vitro, in bovine aortic endothelial cells, odiparcil stimulated the secretion of sulphated GAG into culture media, mainly of chondroitin sulphate (CS) /dermatan sulphate (DS) type. Efficacy of odiparcil in reducing intracellular GAG content was investigated in skin fibroblasts from MPS VI patients where odiparcil was shown to reduce efficiently the accumulation of intracellular CS with an EC50 in the range of 1 μM. In vivo, in wild type rats, after oral administrations, odiparcil was well distributed, achieving μM concentrations in MPS VI disease-relevant tissues and organs (bone, cartilage, heart and cornea). In MPS VI Arylsulphatase B deficient mice (Arsb-), after chronic oral administration, odiparcil consistently stimulated the urinary excretion of sulphated GAG throughout the treatment period and significantly reduced tissue GAG accumulation in liver and kidney. Furthermore, odiparcil diminished the pathological cartilage thickening observed in trachea and femoral growth plates of MPS VI mice. The therapeutic efficacy of odiparcil was similar in models of early (treatment starting in juvenile, 4 weeks old mice) or established disease (treatment starting in adult, 3 months old mice). Our data demonstrate that odiparcil effectively diverts the synthesis of cellular glycosaminoglycans into secreted soluble species and this effect can be used for reducing cellular and tissue GAG accumulation in MPS VI models. Therefore, our data reveal the potential of odiparcil as an oral GAG clearance therapy for MPS VI patients.

Topics: Administration, Oral; Animals; Cattle; Cells, Cultured; Chondroitin Sulfates; Dermatan Sulfate; Disease Models, Animal; Endothelial Cells; Female; Glycosaminoglycans; Glycosides; Humans; In Vitro Techniques; Male; Mice; Mice, Inbred C57BL; Mice, Mutant Strains; Mucopolysaccharidosis VI; Rats; Rats, Sprague-Dawley

Mucopolysaccharidoses (MPS) are complex storage disorders that result in the accumulation of glycosaminoglycans (GAGs) in urine, blood, brain and other tissues. Symptomatic patients are typically screened for MPS by analysis of GAG in urine. Current screening methods used in clinical laboratories are based on colorimetric assays that lack the sensitivity and specificity to reliably detect mild GAG elevations that occur in some patients with MPS. We have developed a straightforward, reliable method to quantify chondroitin sulfate (CS), dermatan sulfate (DS) and heparan sulfate (HS) in urine by stable isotope dilution tandem mass spectrometry. The GAGs were methanolyzed to uronic acid-N-acetylhexosamine or iduronic acid-N-glucosamine dimers and mixed with stable isotope labeled internal standards derived from deuteriomethanolysis of GAG standards. Specific dimers derived from HS, DS and CS were separated by ultra-performance liquid chromatography and analyzed by electrospray ionization tandem mass spectrometry using selected reaction monitoring for each targeted GAG product and its corresponding internal standard. The method was robust with a mean inaccuracy from 1 to 15%, imprecision below 11%, and a lower limit of quantification of 0.4mg/L for CS, DS and HS. We demonstrate that the method has the required sensitivity and specificity to discriminate patients with MPS III, MPS IVA and MPS VI from those with MPS I or MPS II and can detect mildly elevated GAG species relative to age-specific reference intervals. This assay may also be used for the monitoring of patients following therapeutic intervention. Patients with MPS IVB are, however, not detectable by this method.

Topics: Adolescent; Adult; Aged; Child; Child, Preschool; Chondroitin Sulfates; Chromatography, Liquid; Dermatan Sulfate; Glycosaminoglycans; Heparitin Sulfate; Humans; Infant; Middle Aged; Mucopolysaccharidoses; Mucopolysaccharidosis II; Mucopolysaccharidosis III; Mucopolysaccharidosis IV; Mucopolysaccharidosis VI; Radioisotope Dilution Technique; Reference Values; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry; Young Adult

The sulfatase enzymes, N-acetylgalactosamine-4-sulfatase (arylsulfatase B (ASB)) and galactose-6-sulfatase (GALNS) hydrolyze sulfate groups of CS. Deficiencies of ASB and GALNS are associated with the mucopolysaccharidoses. To determine if expression of ASB and GALNS impacts on glycosaminoglycans (GAGs) and proteoglycans beyond their association with the mucopolysaccharidoses, we modified the expression of ASB and GALNS by overexpression and by silencing with small interference RNA in MCF-7 cells. Content of total sulfated GAG (sGAG), chondroitin 4-sulfate (C4S), and total chondroitin sulfates (CSs) was measured following immunoprecipitation with C4S and CS antibodies and treatment with chondroitinase ABC. Following silencing of ASB or GALNS, total sGAG, C4S, and CS increased significantly. Following overexpression of ASB or GALNS, total sGAG, C4S, and CS declined significantly. Measurements following chondroitinase ABC treatment of the cell lysates demonstrated no change in the content of the other sGAG, including heparin, heparan sulfate, dermatan sulfate, and keratan sulfate. Following overexpression of ASB and immunoprecipitation with C4S antibody, virtually no sGAG was detectable. Total sGAG content increased to 23.39 (+/-1.06) microg/mg of protein from baseline of 12.47 (+/-0.68) microg/mg of protein following ASB silencing. mRNA expression of core proteins of the CS-containing proteoglycans, syndecan-1 and decorin, was significantly up-regulated following overexpression of ASB and GALNS. Soluble syndecan-1 protein increased following increases in ASB and GALNS and reduced following silencing, inversely to changes in CS. These findings demonstrate that modification of expression of the lysosomal sulfatases ASB and GALNS regulates the content of CSs.

Topics: Antibodies; Cell Line, Tumor; Chondroitin ABC Lyase; Chondroitin Sulfates; Chondroitinsulfatases; Decorin; Dermatan Sulfate; Extracellular Matrix Proteins; Female; Gene Expression Regulation, Enzymologic; Gene Silencing; Heparin; Heparitin Sulfate; Humans; Mucopolysaccharidosis VI; N-Acetylgalactosamine-4-Sulfatase; Proteoglycans; RNA, Small Interfering; Syndecan-1