Showing papers on "Keratan sulfate published in 2003"
TL;DR: The qualitatively similar expression of glycosaminoglycans shared by fibroblasts and myofibroblast suggests a role for fibro Blasts in deposition of non-transparent fibrotic tissue in pathological corneas.
224 citations
TL;DR: Experimental evidence indicates that the keratan sulfate proteoglycans are involved in the regulation of collagen fibril diameter, and dermatan sulfATE proteoglycan participates in the control of interfibrillar spacing and in the lamellar adhesion properties of corneal collagens.
Abstract: The cornea is a curved and transparent structure that provides the initial focusing of a light image into the eye. It consists of a central stroma that constitutes 90% of the corneal depth, covered anteriorly with epithelium and posteriorly with endothelium. Its transparency is the result of the regular spacing of collagen fibers with remarkably uniform diameter and interfibrillar space. Corneal collagen is composed of heterotypic fibrils consisting of type I and type V collagen molecules. The cornea also contains unusually high amounts of type VI collagen, which form microfibrillar structures, FACIT collagens (XII and XIV), and other nonfibrillar collagens (XIII and XVIII). FACIT collagens and other molecules, such as leucine-rich repeat proteoglycans, play important roles in modifying the structure and function of collagen fibrils.Proteoglycans are macromolecules composed of a protein core with covalently linked glycosaminoglycan side chains. Four leucine-rich repeat proteoglycans are present in the extracellular matrix of corneal stroma: decorin, lumican, mimecan and keratocan. The first is a dermatan sulfate proteoglycan, and the other three are keratan sulfate proteoglycans. Experimental evidence indicates that the keratan sulfate proteoglycans are involved in the regulation of collagen fibril diameter, and dermatan sulfate proteoglycan participates in the control of interfibrillar spacing and in the lamellar adhesion properties of corneal collagens. Heparan sulfate proteoglycans are minor components of the cornea, and are synthesized mainly by epithelial cells. The effect of injuries on proteoglycan synthesis is discussed.
219 citations
TL;DR: Ablation of the Kera gene resulted in subtle structural alterations of collagenous matrix and did not perturb the expression of other SLRPs in cornea, showing that keratocan plays a unique role in maintaining the appropriate corneal shape to ensure normal vision.
186 citations
TL;DR: It is confirmed that aggrecan can inhibit the growth of adult axons in vivo and the inhibitory effects of aggreca may be mediated, at least in part, by structures located on the core glycoprotein in the absence of the bulk of the CS chains.
75 citations
TL;DR: An important role for BGN is suggested in dentin formation and mineralization in predentin, an effect possibly attributable to the deglycosylation action of stromelysin-1.
Abstract: Small leucine-rich proteoglycans (SLRPs) regulate extracellular matrix organization. In order to investigate the distribution and potential functions of decorin, biglycan (BGN), and fibromodulin (3 SLRPs, potentially related to dentinogenesis), we performed light and electron immunochemistry on teeth from rats, and on wild-type and biglycan knockout mice (BGN KO). Immunohistochemical data demonstrate that chondroitin sulfate/dermatan sulfate (CS/DS) and keratan sulfate (KS) distributions displayed reverse gradients in predentin. The decrease of CS/DS labeling from the proximal to the distal predentin contrasted with the sharp decorin increase observed in the distal predentin near the predentin/dentin transition, an effect possibly attributable to the deglycosylation action of stromelysin-1. In contrast, BGN concentration was apparently constant throughout the whole predentin. Additional immunolabelings showed, for the first time, the presence of fibromodulin in predentin. Compared with the wild-type mouse...
53 citations
TL;DR: Results indicate that the SLRP profile of the uterine ECM alters with differentiation of endometrial stromal cells, which may be a prerequisite for the formation of large fibrils in decidua in mice.
Abstract: Remodelling of the extracellular matrix (ECM) occurs during decidualization of the endometrium in mice. Previously we have documented the appearance of large-diameter collagen fibrils around mature decidual cells between day 5 and day 7 of pregnancy. Proteoglycans are important in the regulation of collagen fibrillogenesis, and the present study analysed four members (decorin, biglycan, lumican and fibromodulin) of the family of small leucine-rich proteoglycans (SLRPs) in the uterus from day 1 to day 7 of pregnancy. Decorin was present together with lesser amounts of lumican in the stroma before the onset of decidualization, whereas biglycan and fibromodulin were almost absent. Biglycan and, less significantly, lumican were expressed in decidualized regions of the endometrium, but decorin was absent. Fibromodulin was weakly expressed in the non-decidualized stroma, but only after implantation. Decorin and lumican were strongly expressed in the undifferentiated interimplantation site stroma, whereas biglycan and fibromodulin were expressed only weakly. These results indicate that the SLRP profile of the uterine ECM alters with differentiation of endometrial stromal cells. The large decidual collagen fibrils are thought to arise by lateral association of smaller diameter fibrils. As decorin has been shown to inhibit lateral association of collagen fibrils, its disappearance between day 2 and day 5 of pregnancy may be a prerequisite for the formation of large fibrils in decidua in mice.
52 citations
TL;DR: The results confirm that the 175-kDa rHARE does not require the larger HARE isoform to mediate endocytosis of multiple GAGs, and suggest that temperature-induced conformational changes may alter the GAG specificity of HARE.
50 citations
TL;DR: Activation by these two GAGs was only slightly affected, supporting the contention that the effects of HA, CS4, KS and HS are mediated by one of the isoforms of this CD44 receptor.
49 citations
TL;DR: A role for OSAD in the mineralization process is supported, assumed to be a nucleator of hydroxyapatite crystals, and OSAD could work in concert with BSP to regulate nucleation, however, the mechanisms involved remain to be elucidated.
Abstract: Osteoadherin (OSAD) is a keratan sulfate proteoglycan recently isolated from bovine and rat bone. Based on results obtained from in vitro experiments, the protein was shown to bind osteoblasts via the integrin receptor alpha(v)beta(3). Due to OSAD's capacity to bind hydroxyapatite crystals, a role for the protein in the mineralization process has also been suggested. To test these hypotheses in an in vivo model, the ultrastructural localization of OSAD in bone, tibial (metaphyses and diaphyses). and calvarial samples from normal 10 to 12-day-old rats were examined by immunohistochemical techniques at the ultrastructural level. In addition to the qualitative studies, quantitative measurements of OSAD marker density were performed in relevant compartments. Immunolabeling for OSAD was located to the mineralized bone matrix, with highest concentration of marker at the border between bone and cartilage remnants in the metaphyseal trabeculi. Intracellular labeling was low and no systemic accumulation of OSAD markers was observed at the cell-matrix interface. The observed distribution pattern of OSAD is strikingly similar to that of bone sialoprotein (BSP), confirmed by double labeling. The results of the current study support a role for OSAD in the mineralization process. In this process BSP is assumed to be a nucleator of hydroxyapatite crystals, and OSAD could work in concert with BSP to regulate nucleation. However, the mechanisms involved remain to be elucidated. (Less)
48 citations
TL;DR: Results suggested that β4GalT-IV is a 6SGN-specific β4 GalT and may be involved in the biosynthesis of various glycoproteins carrying a 6-O-sulfatedN-acetyllactosamine moiety.
47 citations
TL;DR: It is hypothesised that a lack of keratocan might lower the number of keratan sulfate proteoglycans that associate with collagen, leading to alterations in their diameters and spatial arrangements, and change the osmotic balance between the inside and outside of fibrils, causing them to swell and move further apart.
TL;DR: Investigation of the ability of TGF beta 1 to modulate the synthesis and accumulation of decorin, biglycan, and fibromodulin in cartilage explants cultured under conditions in which aggrecan synthesis remains relatively constant found the accumulation of each of the three small PGs was affected to a different extent.
TL;DR: The content of the IdoA2Salpha1-->4GalNAc4S sequence in eel skin, which shows anticoagulant activity through binding to heparin cofactor II, was two times higher than that of dermatan sulfate from porcine skin.
TL;DR: Anterior disk displacement leads to molecular alterations in both the collagen and the proteoglycans of rabbit condylar cartilage characteristic of osteoarthritis in other synovial joints, consistent with loss of the shock absorber function of the cartilage and injury of the underlying bone.
Abstract: Background: Results from our previous studies suggest that surgical induction of anterior disk displacement (ADD) in the rabbit craniomandibular joint (CMJ) leads to histopathological alterations consistent with osteoarthritis. In addition, molecular changes in collagens and glycosaminoglycans (GAGs) were observed using immunohistochemistry. The purpose of the present study was to further characterize those molecular changes in collagens and GAGs using immuno-electron microscopy.
Methods: The right joint of 15 rabbits was exposed surgically and all discal attachments were cut except for the posterior attachment (the bilaminar zone). The disc was then repositioned anteriorly and sutured to the zygomatic arch. The left joint was used as a sham-operated control. Ten additional joints were used as non-operated controls. Mandibular condyles were removed 2 weeks following surgery and processed for light and immuno-electron microscopy using colloidal gold-labeled antibodies against collagen type I, II, VI and IX and against keratan sulfate, chondroitin-4 and -6-sulfate, and link protein.
Results: Light microscopic results showed osteoarthritic changes. Immuno-electron microscopy of osteoarthritic cartilage demonstrated a decline in type II collagen, the abnormal presence of type I collagen and loss of type VI and IX collagens. Quantitative colloidal gold immuno-electron microscopy confirmed the depletion of keratan sulfate, chondroitin-4 and -6-sulfate, and link protein in osteoarthritic cartilage.
Conclusion : Anterior disk displacement leads to molecular alterations in both the collagen and the proteoglycans of rabbit condylar cartilage characteristic of osteoarthritis in other synovial joints. These alterations are consistent with loss of the shock absorber function of the cartilage and injury of the underlying bone.
Journal Article•
TL;DR: BAY 12-9566 at daily doses of 100 mg significantly altered proteoglycan turnover, resulting in a cartilage composition reflected by the content of the 846 epitope that is more characteristic of a young growing individual.
Abstract: OBJECTIVE: To determine the effect of BAY 12-9566, a matrix metalloproteinase inhibitor, on articular cartilage metabolism in patients with osteoarthritis (OA). METHODS: Thirty-five patients with OA were randomized to receive oral daily dosing of BAY 12-9566 (25, 100, or 400 mg) or placebo for 3 weeks prior to knee surgery. Cartilage samples were obtained at surgery and examined for markers of proteoglycan aggrecan turnover (846 epitope, a putative synthesis marker, and keratan sulfate epitope content) and type II collagen synthesis (C-propeptide content), cleavage by collagenase (COL 2-3/4C short), denaturation, and content (COL2-3/4m epitope). BAY 12-9566 concentrations were measured by HPLC in serum, synovial fluid, and cartilage. RESULTS: Comparisons between study drug and placebo treatments revealed that at the 100 mg dose there was a significant increase in the 846 epitope (p = 0.012). Total type II collagen content was also higher at this dosage (p = 0.012). Alterations in collagen degradation and synthesis were not detected. CONCLUSION: BAY 12-9566 at daily doses of 100 mg significantly altered proteoglycan turnover, resulting in a cartilage composition reflected by the content of the 846 epitope that is more characteristic of a young growing individual. The increase in this epitope may signify increased matrix synthesis. The increase in type II collagen content was unexpected, since there was no other evidence for altered collagen turnover. However, increased matrix assembly would also be indicated by this increased content.
TL;DR: The hypothesis that keratocan, or ker atocan with minimally sulfated KS chains, may play a role in structuring ECM for early embryonic cell and neuronal migrations is suggested.
TL;DR: High‐resolution NMR analysis of urinary GAGs of patients with MPS types I, II, IIIA, IVA and VI provides a solid basis for future studies with a larger number of patients to further explore pathogenesis and course of the MPS diseases.
Abstract: Patients with different types of mucopolysaccharidoses (MPS) lack specific lysosomal enzymes, which leads to tissue accumulation and urinary excretion of glycosaminoglycans (GAGs). Since little is known about the molecular composition of the excreted GAG fragments, we used two-dimensional [1H,13C]-correlation nuclear magnetic resonance (NMR) spectroscopy for a detailed analysis of the urinary GAGs of patients with MPS types I, II, IIIA, IVA and VI. The method revealed that the molecular structures of the excreted GAGs, i.e. heparan sulfate (HS), dermatan sulfate (DS), chondroitin sulfate (CS), and keratan sulfate (KS) are clearly distinct for the different MPS types. The chain terminal residues that are the normal substrates for the defective enzymes constitute characteristic sets of signals for each MPS type. The GAG chains show variations in carbohydrate composition and sulfation patterns that can be related to the different MPS types and clinical features. For example, two patients with MPS IIIA (M. Sanfilippo) with signs of CNS degeneration but only mild somatic features excrete a highly sulfated variant of HS, resembling HS in porcine brain, whereas a patient with MPS I (M. Scheie) and two patients with MPS II (M. Hunter), who present primarily with coarse facial features, joint contractures and skeletal deformities excrete a different type of HS with lower sulfation. In another case study, a patient with MPS IVA (M. Morquio), who presented mainly with skeletal dysplasia, excreted not only excessive amounts of KS but also a highly sulfated CS variant, resembling CS in articular cartilage. The high-resolution NMR analysis of urinary GAGs presented here for the first time provides a solid basis for future studies with a larger number of patients to further explore pathogenesis and course of the MPS diseases.
TL;DR: A novel KS hydrolase, endo-β-N-acetylglucosaminidase, is purified from the cell pellet and conditioned medium of Bacillus circulans by sequential chromatography using DE52 and phenyl-Sepharose columns and may prove useful for the structural analysis of KS toward achieving an understanding of its function.
TL;DR: The results elucidate the subtle biochemical differences in ECM synthesized by chondrocytes in the presence of type II collagen and further characterize the role played by ECM in the TGF‐β1 regulation of the articular cartilage physiology.
TL;DR: Two novel chromogenic substrates for endo-beta-galactosidase were designed on the basis of the structural features of keratan sulfate and 2 was shown to be remarkably promoted compared to that of 4 by the presence of a 2-acetamide group adjacent to the p-nitrophenyl group.
Abstract: Novel chromogenic substrates for endo-beta-galactosidase were designed on the basis of the structural features of keratan sulfate. Galbeta1-4GlcNAcbeta1-3Galbeta1-4GlcNAcbeta-pNP (2), which consists of two repeating units of N-acetyllactosamine, was synthesized enzymatically by consecutive additions of GlcNAc and Gal residues to p-nitrophenyl beta-N-acetyllactosaminide. In a similar manner, GlcNAcbeta1-3Galbeta1-4GlcNAcbeta-pNP (1), GlcNAcbeta1-3Galbeta1-4Glcbeta-pNP (3), Galbeta1-4GlcNAcbeta1-3Galbeta1-4Glcbeta-pNP (4), Galbeta1-3GlcNAcbeta1-3Galbeta1-4Glcbeta-pNP (5), and Galbeta1-6GlcNAcbeta1-3Galbeta1-4Glcbeta-pNP (6) were synthesized as analogues of 2. Endo-beta-galactosidases released GlcNAcbeta-pNP or Glcbeta-pNP in an endo-manner from each substrate. A colorimetric assay for endo-beta-galactosidase was developed using the synthetic substrates on the basis of the determination of p-nitrophenol liberated from GlcNAcbeta-pNP or Glcbeta-pNP formed by the enzyme through a coupled reaction involving beta-N-acetylhexosaminidase (beta-NAHase) or beta-d-glucosidase. Kinetic analysis by this method showed that the value of Vmax/Km of 2 for Escherichia freundii endo-beta-galactosidase was 1.7-times higher than that for keratan sulfate, indicating that 2 is very suitable as a sensitive substrate for analytical use in an endo-beta-galactosidase assay. Compound 1 still acts as a fairly good substrate despite the absence of a Gal group in the terminal position. In addition, the hydrolytic action of the enzyme toward 2 was shown to be remarkably promoted compared to that of 4 by the presence of a 2-acetamide group adjacent to the p-nitrophenyl group. This was the same in the case of a comparison of 1 and 3. Furthermore, the enzyme also catalysed a transglycosylation on 1 and converted it into GlcNAcbeta1-3Galbeta1-4GlcNAcbeta1-3Galbeta1-4GlcNAcbeta-pNP (9) and GlcNAcbeta1-3Galbeta1-4GlcNAcbeta1-3Galbeta1-4GlcNAcbeta1-3Galbeta1-4GlcNAcbeta-pNP (10) as the major products, which have N-acetyllactosamine repeating units.
TL;DR: The findings indicate that the HNK‐1 carbohydrate may be a common modifier of several proteoglycans (such as aggrecan) that are usually expressed early in development, and that H NK‐1 addition to these molecules may be regulated by tissue‐ and temporal‐specific expression of requisite sulfotransferases and glycosyltransferases.
Abstract: Previously, we showed that the HNK-1 carbohydrate epitope is expressed on aggrecan synthesized in the notochord but not in mature cartilage. In the present study, we demonstrate that in immature cartilage (embryonic day 6) the HNK-1 epitope is also expressed predominantly on aggrecan proteoglycan molecules. This finding was verified by using an aggrecan-deficient mutant, the nanomelic chick, which lacks HNK-1 immunostaining in the extracellular matrix of dividing and hypertrophic chondrocytes as late as embryonic day 12. By using both biochemical and immunologic approaches, the initially prominent expression of the HNK-1 epitope is down-regulated as development of limb and vertebral cartilage proceeds, so that by embryonic day 14 no HNK-1 is detectable. Localization changes with development and the HNK-1-aggrecan matrix becomes restricted to dividing and hypertrophic chondrocytes and is particularly concentrated in the intraterritorial matrix. Concomitant with the temporal and spatial decreases in HNK-1, there is a significant increase in keratan-sulfate content and the aggrecan-borne HNK-1 epitope is closely associated with proteolytic peptides that contain keratan sulfate chains, rather than chondroitin sulfate chains or carbohydrate-free domains. Lastly, the diminution in HNK-1 expression is consistent with a reduction in mRNA transcripts specific for at least one of the key enzymes in HNK-1 oligosaccharide biosynthesis, the HNK-1 sulfotransferase. These findings indicate that the HNK-1 carbohydrate may be a common modifier of several proteoglycans (such as aggrecan) that are usually expressed early in development, and that HNK-1 addition to these molecules may be regulated by tissue- and temporal-specific expression of requisite sulfotransferases and glycosyltransferases.
TL;DR: Hyaluronan, chondroitin sulfate and heparan sulfate are expressed in nerve fiber-rich layers during early postnatal stages and may regulate neurite outgrowth in adulthood and may be associated with the structure of the inner limiting membrane.
Abstract: Purpose. To investigate the spatiotemporal expression of glycosaminoglycans during development of the rat retina. Methods. Hyaluronan and sulfated glycosaminoglycans, including chondroitin sulfate, heparan sulfate and keratan sulfate were detected using biotinylated hyaluronan binding protein, immunohistochemical analysis, respectively, in the rat retina at various stages of development. Results. Hyaluronan was expressed in the nerve fiber layer, inner plexiform layer and outer plexiform layer during early postnatal stages (postnatal day 1–14; P1–P14) and was undetectable after P21. In contrast, hyaluronan was faintly observed in the photoreceptor layer on P7, and gradually increased up to P49. The spatiotemporal expression pattern of chondroitin sulfate was similar to that of hyaluronan. Heparan sulfate was also detected in the nerve fiber layer, inner plexiform layer and outer plexiform layer during early postnatal stages (P1–P14). In addition, heparan sulfate was expressed in the inner limiting membran...
TL;DR: With EC‐specific and formalin‐resistant characteristics, 4C4 may be a specific marker for diagnosing EC among a variety of germ cell tumours.
Abstract: Germ cell tumours, the most common solid cancers in young males, display pluripotentiality for embryonal and somatic differentiation. Specific surface antigens are useful in the study of cellular differentiation and for clinical diagnosis. A mouse monoclonal antibody (4C4-mAb) has been developed against a human embryonal carcinoma (EC) cell line (NCR-G3) isolated from a combined form of testicular germ cell tumour. On immunohistological and immuno-electron microscopic examination, the 4C4 antigen (4C4) was detected on the surface of NCR-G3 and gold particles were exclusively detected on the microvilli of the cells. In both formalin-fixed paraffin wax sections and touch-smear specimens, 4C4 was detected specifically in EC, while the antigen was not expressed in other types of germ cell tumour or in the other solid tumours tested. Tunicamycin diminished the antigenicity of NCR-G3 cells. In biochemical studies, 4C4 was found in a high molecular weight region ranging from 1 x 10(6) to 1 x 10(7) kD, which disappeared after periodate treatment. The density of 4C4 was 1.5 g/cm(3) after equilibrium centrifugation. These results imply that 4C4 is a proteoglycan. Furthermore, endo- and exo-glycosidase treatment revealed that 4C4 is a keratan sulphate proteoglycan that contains sialyl and fucosyl moieties. With EC-specific and formalin-resistant characteristics, 4C4 may be a specific marker for diagnosing EC among a variety of germ cell tumours.
Patent•
20 Feb 2003
TL;DR: In this paper, a safe and easy method for producing low-molecular weight glycosaminoglycan is proposed, which is irradiated with ultraviolet rays to reduce molecular weight.
Abstract: PROBLEM TO BE SOLVED: To provide a safe and easy method for producing low-molecular weight glycosaminoglycan SOLUTION: The method for producing the glycosaminoglycan with the reduced molecular weight involves irradiating a glycosaminoglycan with ultraviolet rays The glycosaminoglycan is selected from the group consisting of hyaluronic acid, chondroitin, chondroitin sulfate, dermatan sulfate, heparin, heparan sulfate and keratan sulfate COPYRIGHT: (C)2004,JPO&NCIPI
Patent•
20 Feb 2003
TL;DR: In this article, the authors carried out corneal incision, cornea stratification, paracentesis and introducing a sterile water-soluble mixture of glycosamine glycans like keratan sulfate and chondroitin sulfate in 25:75 proportion.
Abstract: FIELD: medicine. SUBSTANCE: method involves carrying out corneal incision, cornea stratification, paracentesis and introducing sterile water-soluble mixture of glycosamine glycans like keratan sulfate and chondroitin sulfate in 25:75 proportion. EFFECT: enhanced effectiveness of keratoprotective action.