Showing papers on "Keratan sulfate published in 1978"

Deficiencies of glucosamine-6-sulfate or galactosamine-6-sulfate sulfatases are responsible for different mucopolysaccharidoses.

Abstract: [1-3H]Galactitol-6-sulfate, N- [1-3H]acetylgalactosaminitol-6-sulfate, N-[1-3H]acetylglucosaminitol-6-sulfate, N-acetylglucosamine-6-sulfate, and 6-sulfated tetrasaccharides from chondroitin-6-sulfate have been used for the measurement of 6-sulfatase activity of extracts of normal skin fibroblasts and of fibroblasts cultured from patients with genetic mucopolysaccharidoses. With these substrates, extracts of fibroblasts derived from Morquio patients lack or have greatly reduced activities for galactitol-6-sulfate, N-acetylgalactosaminitol-6-sulfate, and 6-sulfated tetrasaccharides but have normal activity for N-acetylglucosamine-6-sulfate and its alditol; those derived from a patient with a newly discovered mucopolysaccharidosis have greatly reduced activity for N-acetylglucosamine-6-sulfate and its alditol but normal activity for galactitol-6-sulfate, N-acetylgalactosaminitol-6-sulfate, and the 6-sulfated tetrasaccharides. These findings demonstrate the existence of two different hexosamine-6-sulfate sulfatases, specific for the glucose or galactose configuration of their substrates. Their respective deficiencies, causing inability to degrade keratan sulfate and heparan sulfate in one case and keratan sulfate and chondroitin-6-sulfate in the other, are responsible for different clinical phenotypes.

Topographical distribution of sulfated glycosaminoglycans in the surface layers of the human temporomandibular joint. A histochemical study of an autopsy material.

Abstract: . The right temporomandibular joint (TMJ) was removed at autopsy from 18 individuals and the articular surfaces were scored for macroscopic lesions. Soft tissue specimens were cut out of the medial, lateral and posterior parts of the temporal and condylar components and frozen. The sections were stained with toluidine blue (1-N HC1 solution) and with alcian blue (CEC method) for sulfated glycosaminoglycans. The sections were examined for inter- and pericellular metachromasia and alcian blue staining. Macroscopic surface lesions were found in 14 of the joints. The highest score of inter-and pericellular metachromasia was found in the anterior parts of the joints and a negative correlation was found between the score of surface lesions and that of intercellular metachromasia. Pericellular metachromasia was found mainly in the mineralized cartilage and cartilage layers of the articular surface. Although the CEC values of pericellular staining commonly reached a level indicating the presence of keratan sulfate, the majority of the CEC values found corresponded to those of chondroitin-dermatan sulfate. It was concluded that sulfated GAG are localized mainly to the anterior part of the TMJ and that macroscopic TMJ surface lesions are associated with a reduction of sulfated glycosaminoglycans.

Synthesis of glycosaminoglycans by cultures of normal human corneal endothelial and stromal cells.

Abstract: Monolayer cultures of normal human corneal endothelial and stromal cells were incubated with [35S]sulfate and [3H]glucosamine for 4 hr. The labeled glycosaminoglycans resulted from this incubation were isolated from the cell layer and the growth medium and further characterized. Both endothelial and stromal cell cultures synthesized a variety of sulfated glycosaminoglycans, with chondroitin 6-sulfate as the major product. Chondroitin 4-sulfate, dermatan sulfate, and heparan sulfate were present in smaller amounts. Keratan sulfate was produced only in minimal amounts. Both cell types also synthesized hyaluronic acid. The hyaluronic acid production in stromal cell strains derived from donors of different ages was similar. The demonstration that the endothelial cell strain derived from a 1-day-old baby contained more hyaluronic acid than cultures from older donors suggests a possible age-related phenomenon as seen in developing tissues.

N-acetylglucosamine-6-sulfate sulfatase in man: deficiency of the enzyme in a new mucopolysaccharidosis.

Abstract: Summary: The study of a 5-year old patient with a mucopolysaccharidosis different from those already known has given the opportunity to describe the clinical, biochemical and enzymic characteristics of JV-acetylglucosamine-6-sulfate sulfatase deficiency. The patient was delayed physically and mentally, was hyperactive, and had a short attention span. He had fair complexion and very blond, but coarse and excessive hair. He had mild hepato-splenomegaly and dysostosis multiplex, including hypoplastic odontoid process of the atlas, ovoid vertebral bodies, small femoral epiphyses, and modest enlargement of the ribs. He had a mild, bilateral conductive hearing loss. The urine gave a strongly positive spot test with Azur A paper. Quantitative measurement of urinary glycosaminoglycans demonstrated increased excretion and inadequate degradation of heparan sulfate and keratan sulfate. The microscopic examination of the stained peripheral leukocytes revealed metachromatic material which formed a ring on the inner aspect of the cellular membrane in 20% of the lymphocytes. The rate of degradation of 35SO4-labeled intracellular glycosaminoglycans by cutaneous fibroblasts was delayed and inadequate. The measurements of several lysosomal enzymes whose deficiencies are responsible for the known mucopolysaccharidoses gave results within normal ranges. GaIactose-6-sulfate (Gal-6-S), N-acetylgalactosamine-6-sulfate (GalNAc-6-S), and N-acetylglu-cosamine-6-sulfate (GlcNAc-6-S) were prepared with chlorosulfonic acid, according to the method of Suzuki and Strominger (38). After chromatographic purification, aliquots of the three 6-sulfated monosaccharides were reduced with sodium borotritide. Measurements of Gal-6-S sulfatase, GalNAc-6-S sulfatase, and GlcNAc-6-S sulfatase were performed on extracts of normal cultured fibroblasts and of fibroblasts of the propositus, his parents, and several Morquio patients. Additionally, GalNAc-6-S sulfatase and GlcNAc-6-S sulfatase activities were also measured, using as substrate 500 nmol tetrasaccharide obtained from either chon-droitin-6-sulfate or nonradioactive GlcNAc-6-S. The measurement demonstrated that the propositus has a defective GlcNAc-6-S sulfatase activity, but normal activities for Gal-6-S and GalNAc-6-S sulfatase. These findings are in contrast with those found with fibroblast extracts of Morquio patients, since they have low or nondetectable activities of Gal-6-S and GalNAc-6-S sulfatase but normal GlcNAc-6-S sulfatase activity. Extracts of leukocytes and fibroblasts of the propositus' parents, when tested with radioactive or nonradioactive substrates, had normal levels of GalNAc-6-S sulfatase activity but decreased levels of GlcNAc-6-S sulfatase activity (50–60% of normal). Speculation: The possible existence of two different sulfatases, specific for 6-sulfated hexoses with the glucose or galactose configuration, has been suggested (10). The study of a patient with a novel mucopolysaccharidosis, characterized by defective degradation of keratan sulfate and heparan sulfate, has provided the opportunity of describing the clinical and biochemical features of GlcNAc-6-S sulfatase deficiency. These findings confirm that the defective degradation of keratan sulfate and chondroitin-6-sulfate typical of classic Morquio disease is caused by the deficiency of a sulfatase specific for Gal-6-S and GalNAc-6-S.

Increased urinary excretion of keratan sulfate in fucosidosis.

Abstract: In two children exhibiting the clinical symptoms of fucosidosis, the diagnosis was biochemically ascertained by the demonstration of a profound altpha-L-fucosidase deficiency in cultured skin fibroblasts. The non-dialysed urines of these fucosidosis patients were separated into two fractions by chromatography on Biogel P-2. The first fraction containing the glycosaminoglycans was further fractionated on Dowex 1 X 2 by stepwise elution with increasing NaCl concentrations. Keratan sulfate-chondroitin sulfates attached to the same peptide core were assayed and characterised mainly in the fractions eluted with 1.25, 1.5, 2.0 and 3.0 mol/1 NaCl. Whereas the excretion of normal children of the same age was found to be 0.77 mumol glucosamine equivalents per day in the 2 mol/1 and 3 mol/1 NaCl fraction, the two patients excreted 6.7 (M. C.) and 3.5 (M. S.) mumol glucosamine equivalents per day, respectively. Since keratan sulfate contains alpha-fucose at the non-reducing terminal, this increase in excretion of long chain keratan sulfate in fucosidosis could result from impaired degradation of keratan sulfate, due to the alpha-fucosidase deficiency.

540 a keratan and heparan sulfaturia - a new mucopolysac- charidosis with n-acetylglucosamine 6− sulfatase deficiency

Abstract: A 3½-year old child with severe skeletal dysplasia similar to Morquio syndrome, but with mental retardation had increased urinary mucopolysaccharides with unusual composition of 20% heparan sulfate and 75% keratan sulfate. Extracts of cultured skin fibroblasts from the patient contained normal levels of aryl sulfatases A, B and C, β-N-acetylhexosaminidase and β-galactosidase. Fibroblast extracts were incubated with (35S) N-acetylgalactosamine 6-sulfate as substrate and were found to have normal activity of the enzyme hydrolyzing this substrate. This finding is in contrast to Morquio syndrome where a deficiency of this enzyme is characteristic. A disaccharide containing (35S) N-acetylglucosamine 6-sulfate was prepared from chick embryo keratan sulfate. A profound deficiency in the hydrolysis of 35SO4 (1%) from this substrate was observed, while extracts of Morquio and normal fibroblasts readily hydrolyze (25%) 35SO4 from this substrate. On the basis of these data a new mucopoly-saccharidosis, distinct from Morquio syndrome, with a different sulfatase deficiency (N-acetylglucosamine 6-sulfatase) is described. The deficiency in Morquio syndrome is that of N-acetylgalactosamine and galactose 6-sulfatase. DiFerrante et al. (Science, in press) have reported similar findings in another patient. Supported by Nat'l Foundation Grant 244-39-66-321.

Undersulfated Urinary Glycosaminoglycans in Preterm Newborns

Abstract: The glycosaminoglycans (GAG) isolated from pooled urine of preterm newborns were fractionated by step wise elution from a Dowex 1-X2 column. Analytical reactions, cellulose acetate electrophoresis and enzymatic digestions with chondroitinases and testicular hyaluronidase were performed on each fraction. Chondroitin-4-sulfate and chondroitin-6-sulfate constitute about 60% of urinary GAG; heparan sulfate amounts to about 20%, while chondroitin represents 12% of total GAG; dermatan sulfate, hyaluronic acid and keratan sulfate are present in small traces. Approximately 30% of the total is constituted by nonsulfated GAG.

Preliminary observations on the synthesis of glycosaminoglycans in the sea urchin embryo.

Abstract: A method based on the degradation by enzymes and nitrous acid of isotopically labelled glycosaminoglycans has been employed to study the synthesis of these compounds in normal, animalized and vegetalized sea urchin embryos. According to standard criteria, these organisms synthesize dermatan sulfate, heparan sulfate, hyaluronate and keratan sulfate. The hyaluronate seems to be slightly sulfated, it may thus be mucoitin sulfate. The preliminary results obtained suggest a conspicuous difference between animalized and vegetalized embryos: the synthesis of dermatan sulfate is suppressed in the former, while proceeding normally in the latter. The synthesis of heparan sulfate is not affected by our experimental conditions, but the isotope incorporation in hyaluronate and in keratan sulfate is decreased, more in the vegetalized than in the animalized embryos.

Excretion patterns of glycosaminoglycans in the urine of normal children and adults

Abstract: The glycosaminoglycans excretion was studied in the urine of normal human subjects from newborns to 68 years of age. The glycosaminoglycans preparation was made by digesting the urine with proteolytic enzymes followed by removal of enzyme and undigested protein and finally freeze-drying of the supernatant. Cellulose acetate electrophoresis was carried out on these preparations. Electrophoresis of urinary concentrates results in three alcian blue positive fractions. The proportion with the mobility of chondroitin sulfates fraction was high in childhood and thereafter decreased gradually with age, and that of heparan sulfate and keratan sulfate fraction was low in childhood. Any significant change in the fraction corresponding with hyaluronic acid could not be observed throughout the life.