Keratan sulfate

About: Keratan sulfate is a research topic. Over the lifetime, 1253 publications have been published within this topic receiving 57984 citations. The topic is also known as: keratan sulfate & KS.

Measurement of activities of human serum sulfotransferases which transfer sulfate to the galactose residues of keratan sulfate and to the nonreducing end N-acetylglucosamine residues of N-acetyllactosamine trisaccharide: comparison between normal controls and patients with macular corneal dystrophy.

Abstract: Human serum sulfotransferase activities were measured in normal controls and patients with macular corneal dystrophy (MCD), an inherited disorder characterized by the decreased sulfation of keratan sulfate in the corneal stroma and serum, using two kinds of acceptor: partially desulfated keratan sulfate and a trisaccharide with a GlcNAc residue at the nonreducing terminal, GlcNAcbeta1-3Galbeta1-4GlcNAc. When partially desulfated keratan sulfate was used as the acceptor, only sulfotransferase activity which transfers sulfate to position 6 of the Gal residues was detected. In contrast, when GlcNAcbeta1-3Galbeta1-4GlcNAc was used as the acceptor, sulfotransferase activity which transfers sulfate to position 6 of the nonreducing terminal GlcNAc residue could be detected. Although keratan sulfate levels in the sera of MCD patients determined by ELISA were much lower than those in normal controls, there were no detectable differences in either the sulfotransferase activity responsible for the sulfation of position 6 of Gal residues or that responsible for the sulfation of position 6 of nonreducing end GlcNAc residues between normal controls and MCD patients. These results suggest that the sulfotransferase involved in the sulfation of keratan sulfate, which is assumed to be deficient in MCD patients, may not be secreted into the serum, and that direct measurement of the sulfotransferase activity present in affected tissues such as the cornea instead of serum may be necessary to confirm the postulated deficiency in the biosynthesis of keratan sulfate in MCD.

The glycosaminoglycan interactome 2.0.

Abstract: Glycosaminoglycans (GAGs) are complex linear polysaccharides, which are covalently attached to core proteins (except for hyaluronan) to form proteoglycans. They play key roles in the organization of the extracellular matrix, and at the cell surface where they contribute to the regulation of cell signaling and of cell adhesion. To explore the mechanisms and pathways underlying their functions, we have generated an expanded dataset of 4290 interactions corresponding to 3464 unique GAG-binding proteins, four times more than the first version of the GAG interactome (Vallet and Ricard-Blum, 2021 J Histochem Cytochem 69:93-104). The increased size of the GAG network is mostly due to the addition of GAG-binding proteins captured from cell lysates and biological fluids by affinity chromatography and identified by mass spectrometry. We review here the interaction repertoire of natural GAGs and of synthetic sulfated hyaluronan, the specificity and molecular functions of GAG-binding proteins, and the biological processes and pathways they are involved in. This dataset is also used to investigate the differences between proteins binding to iduronic acid-containing GAGs (dermatan sulfate and heparin/heparan sulfate) and those interacting with GAGs lacking iduronic acid (chondroitin sulfate, hyaluronan, and keratan sulfate).

Age-related changes in the localization of glycosaminoglycans in condylar cartilage of the mandible in rats

Abstract: There is little information available regarding the morphological and biomolecular characteristics of mandibular condylar cartilage. The purpose of this study was to determine the age-related changes in the morphology and immunolocalization of glycosaminoglycans (GAGs) in mandibular condyles. The mandibular condylar cartilages from 4-, 8-, 16-, 32-, and 64-week-old Wistar male rats were examined to verify the localization of chondroitin-4-sulfate (Ch-4S), chondroitin-6-sulfate (Ch-6S) and keratan sulfate (KS) using an indirect immunofluorescent technique with three monoclonal antibodies for glycosaminoglycans, 2-B-6, 3-B-3 and 5-D-4, respectively. Morphologically, the condylar cartilage was a growth cartilage during growing periods, began to differentiate into articular cartilage from the central area of 16-week-old condyles, and became mature articular cartilage at 32 weeks of age. A regional difference was found in the morphological features and distribution of GAGs between the anterior, central, postero-superior and posterior areas of the condyles at each age. The immunohistochemical localizations of these three glycosaminoglycans showed age-related, morphology-dependent changes, from growth cartilage to articular cartilage-like cartilage. Immunoreactions for all of the antibodies decreased progressively with age in the interterritorial matrix, while the pericellular and territorial matrix in the condylar cartilage of the mandible maintained relatively higher immunoreactivity. In conclusion, age-related and regional differences in the localization of glycosaminoglycans Ch-4S, Ch-6S, and KS were found in the mandibular condyles in rats, and these changes are believed to be related to functional and developmental requirements.

Immunohistochemical localization of glycosaminoglycans with the use of monoclonal antibodies in salivary pleomorphic adenomas.

Abstract: Immunohistochemical identification of glycosaminoglycans (GG) in salivary pleomorphic adenomas (63 cases) was made to evaluate chondrogenesis in modified myoepithelial cell regions. Monoclonal antibodies (MoAbs) to GGs were used in conjunction with specific enzyme digestion, and chondroitin 4S proteoglycan (C4SPG), chondroitin 6S PG(C6SPG), dermatan sulfate PG(DSPG), heparan sulfate PG(HSPG) and keratan sulfate PG(KSPC) were identified. Modified myoepithelial cells showing fibrillar and plasmatoid shapes contained KSPG (68%), DSPG (32%) and CSPG(C6SPG:22%, C4SPG:33%). Foci of chondroidally changed cells stained intensely for KSPG (53%), and less so for CSPG(C6SPG:22%, C4SPG:33%), and DSPG (19%). Perinuclear matrix in chondroidal tissue reacted most strongly. Almost all types of modified myoepithelial cells, or outer layer tumor cells of tubulo-ductal structures, produced or synthesized CSPG, DSPG, and HSPG. Certain cells located in hyalinous and myxomatous tissues may undergo chondroidal metaplasia, and clusters of such cells may produce GGs and PGs in the perinuclear zone similar to those GGs in matrix synthesized in chondroidal tissue. GG-synthesizing cells might continuously produce KSPG until the cartilage matrix is completed.