Showing papers on "Chondroitin sulfate published in 1996"
TL;DR: The results show that entry of type O FMDV into cells is a complex process and suggest that the initial contact with the cell surface is made through heparan sulfate.
Abstract: Foot-and-mouth disease virus (FMDV) enters cells by attaching to cellular receptor molecules of the integrin family, one of which has been identified as the RGD-binding integrin alpha(v)beta3. Here we report that, in addition to an integrin binding site, type O strains of FMDV share with natural ligands of alpha(v)beta3 (i.e., vitronectin and fibronectin) a specific affinity for heparin and that binding to the cellular form of this sulfated glycan, heparan sulfate, is required for efficient infection of cells in culture. Binding of the virus to paraformaldehyde-fixed cells was powerfully inhibited by agents such as heparin, that compete with heparan sulfate or by agents that compete for heparan sulfate (platelet factor 4) or that inactivate it (heparinase). Neither chondroitin sulfate, a structurally related component of the extracellular matrix, nor dextran sulfate appreciably inhibited binding. The functional importance of heparan sulfate binding was demonstrated by the facts that (i) infection of live cells by FMDV could also be blocked specifically by heparin, albeit at a much higher concentration of inhibitor; (ii) pretreatment of cells with heparinase reduced the number of plaques formed compared with that for untreated cells; and (iii) mutant cell lines deficient in heparan sulfate expression were unable to support plaque formation by FMDV, even though they remained equally susceptible to another picornavirus, bovine enterovirus. The results show that entry of type O FMDV into cells is a complex process and suggest that the initial contact with the cell surface is made through heparan sulfate.
388 citations
TL;DR: It is proposed that wingless belongs to the group of growth factor ligands whose actions are mediated by extracellular proteoglycan molecules.
Abstract: Wingless, the Drosophila homologue of the proto-oncogene Wnt-1, encodes a secreted glycoprotein that regulates differentiation and proliferation of nearby cells. Here we report on the biochemical mechanism(s) by which the wingless signal is transmitted from cell to cell. When expressed in S2 cells, the majority (approximately 83%) of secreted wingless protein (WG) is bound to the cell surface and extracellular matrix through specific, noncovalent interactions. The tethered WG can be released by addition of exogenous heparan sulfate and chondroitin sulfate glycosaminoglycans. WG also binds directly to heparin agarose beads with high affinity. These data suggest that WG can bind to the cell surface via naturally occurring sulfated proteoglycans. Two lines of evidence indicate that extracellular glycosaminoglycans on the receiving cells also play a functional role in WG signaling. First, treatment of WG-responsive cells with glycosaminoglycan lyases reduced WG activity by 50%. Second, when WG-responsive cells were preincubated with 1 mM chlorate, which blocks sulfation, WG activity was inhibited to near-basal levels. Addition of exogenous heparin to the chlorate-treated cells was able to restore WG activity. Based on these results, we propose that WG belongs to the group of growth factor ligands whose actions are mediated by extracellular proteoglycan molecules.
317 citations
TL;DR: Assays with purified reagents show that the fucosylated chondroitin sulfate can potentiate the thrombin inhibition activity of both antithrombin and heparin cofactor II.
299 citations
TL;DR: It is suggested that interaction between 6B4 proteoglycan and pleiotrophin is required for the action of pleiotrhin, and chondroitin sulfate chains on 6B 4 proteogly can play regulatory roles in its binding.
284 citations
TL;DR: Immunocytochemical studies of embryonic and early postnatal nervous tissue showed an overlapping localization of TAG-1/axonin-1 with all four of these ligands, further supporting the biological significance of their ability to interact in vitro.
207 citations
TL;DR: Findings provide strong evidence that the MBP-MOMP functions as a chlamydial cytoadhesin and that heparan sulfate proteoglycans are the host-cell receptors to which the MOMP binds.
Abstract: Chlamydial attachment to columnar conjunctival or urogenital epithelial cells is an initial and critical step in the pathogenesis of chlamydial mucosal infections. The chlamydial major outer membrane protein (MOMP) has been implicated as a putative chlamydial cytoadhesin; however, direct evidence supporting this hypothesis has not been reported. The function of MOMP as a cytoadhesin was directly investigated by expressing the protein as a fusion with the Escherichia coli maltose binding protein (MBP-MOMP) and studying its interaction with human epithelial cells. The recombinant MBP-MOMP bound specifically to HeLa cells at 4 degrees C but was not internalized after shifting the temperature to 37 degrees C. The MBP-MOMP competitively inhibited the infectivity of viable chlamydiae for epithelial cells, indicating that the MOMP and intact chlamydiae bind the same host receptor. Heparan sulfate markedly reduced binding of the MBP-MOMP to cells, whereas chondroitin sulfate had no effect on binding. Enzymatic treatment of cells with heparitinase but not chondroitinase inhibited the binding of MBP-MOMP. These same treatments were also shown to reduce the infectivity of chlamydiae for epithelial cells. Mutant cell lines defective in heparan sulfate synthesis but not chondroitin sulfate synthesis showed a marked reduction in the binding of MBP-MOMP and were also less susceptible to infection by chlamydiae. Collectively, these findings provide strong evidence that the MOMP functions as a chlamydial cytoadhesin and that heparan sulfate proteoglycans are the host-cell receptors to which the MOMP binds.
181 citations
TL;DR: When fully deacetylated chitosan is contacted in solution with chondroitin sulfates and hyaluronic acid, pure polyelectrolyte complexes are formed as mentioned in this paper.
170 citations
Journal Article•
TL;DR: Through their interactions with neural cell adhesion and extracellular matrix molecules, these proteoglycans may play a major role in modulating cellAdhesion, neurite growth, and signal transduction across the plasma membrane during the development of the CNS.
Abstract: Neurocan is a multidomain hyaluronan-binding chondroitin sulfate proteoglycan that is synthesized by neurons, whereas the astroglial proteoglycan phosphacan is an mRNA splice variant representing the entire extracellular portion of a receptor-type protein tyrosine phosphatase. A glycoform of phosphocan (phosphocan-KS) that contains both chondroitin sulfate and keratan sulfate is present in the postnatal rat central nervous system (CNS). The concentration of neurocan in brain increases during late embryonic development but then declines steeply during the early postnatal period together with hyaluronan, and neurocan also undergoes extensive proteolytic processing during the course of brain development. In contrast, the concentrations of both phosphocan and phosphocan-KS rise steadily after embryonic day 20 to reach a plateau at about 2 weeks postnatally. In the embryonic CNS the distribution of neurocan mRNA is more widespread than that of phosphocan, which is primarily present in regions of active cell proliferation. Neurocan mRNA is also present in areas where the proteoglycan is not expressed, and there is evidence that the short open reading frame in its 5'-leader may function as a cis-acting regulatory signal for the modulation of neurocan expression in the developing CNS. Neurocan and phosphocan bind saturably, reversibly, and with high affinity to neural cell adhesion molecules (Ng-CAM/L1, NCAM, TAG-1/axonin-1) and to tenascin-C. The proteoglycans and their ligands have overlapping localizations in the CNS, and binding of phosphocan to Ng-CAM/L1, NCAM, and tenascin-C is mediated by complex-type N-linked oligosaccharides on the proteoglycan. Neurocan and phosphocan also bind to neurons and are potent inhibitors of neuronal and glial adhesion and neurite outgrowth. Through their interactions with neural cell adhesion and extracellular matrix molecules, these proteoglycans may play a major role in modulating cell adhesion, neurite growth, and signal transduction across the plasma membrane during the development of the CNS.
163 citations
Journal Article•
TL;DR: The data provide the first quantitative biochemical profiles of GAGs of individual normal andPOAG TM, and it is suggested that a depletion of hyaluronic acid and the accumulation of chondroitin sulfates may increase aqueous outflow resistance in the POAG TM.
Abstract: PURPOSE: Glycosaminoglycans (GAGs) contribute to the filtration barrier of aqueous outflow through the trabecular meshwork (TM). The purpose of this biochemical study was to identify the type and amount of GAGs in normal and in primary open-angle glaucoma (POAG) TM and adjacent anterior segment structures. METHODS: The GAGs of 21 masked individual normal and POAG human TMs, as well as iris, ciliary body, and anterior sclera, were isolated biochemically, identified by selective GAG-degrading enzymes, and quantitated by computer-enhanced densitometry. RESULTS: In 10 normal TMs (8 donors, 65 to 83 years of age), the GAG profile was: hyaluronic acid (0.77 +/- 0.26 ng/microgram dry-defatted weight +/- SEM); chondroitin 4(6-) sulfates and dermatan sulfate, collectively referred to as chondroitin sulfates (1.90 +/- 0.13 ng); keratan sulfates (0.33 +/- 0.06 ng); heparitin sulfates (2.02 +/- 0.52 ng); GAG enzyme-resistant material (0.02 +/- 0.01 ng); and total GAGs (5.05 +/- 0.70 ng). In 10 POAG TMs (6 donors, 67 to 88 years of age), the GAG profile was: hyaluronic acid (0.18 +/- 0.11 ng; P < 0.02, a 77% decrease; 6 of 10 TMs contained no detectable hyaluronic acid); chondroitin sulfates (2.39 +/- 0.31 ng); keratan sulfates (0.21 +/- 0.06 ng); heparitin sulfates (1.36 +/- 0.43 ng); GAG enzyme-resistant material (0.08 +/- 0.01 ng; P < 0.02); and total GAGs (4.09 +/- 0.33 ng; statistically insignificant). In the POAG iris, hyaluronic acid content was less (82% decrease, P < 0.02), and the chondroitin sulfates content was higher (72% increase, P < 0.02). Similarly, the POAG ciliary body and anterior sclera contained less hyaluronic acid and more chondroitin sulfates. The GAG profile of a "glaucoma suspect" donor specimen was similar to that of the POAG donor specimen. CONCLUSIONS: The data provide the first quantitative biochemical profiles of GAGs of individual normal and POAG TM, and we suggest that a depletion of hyaluronic acid and the accumulation of chondroitin sulfates may increase aqueous outflow resistance in the POAG TM:
153 citations
TL;DR: The findings suggest that ryudocan may possess multiple biological functions, such as bFGF modulation, neurite growth promotion, and anticoagulation, via HS-binding effectors in the cellular microenvironment.
120 citations
TL;DR: Results show that the NG2 molecule is expressed by malignant hematopoietic cells that have abnormalities in chromosome band 11q23, suggesting that antibody 7.1 may be useful in the rapid identification of this group of poor-prognosis patients.
TL;DR: High-performance liquid chromatography of glycosaminoglycan (GAG)-derived oligosaccharides has been employed for the structural analysis and measurement of hyaluronan, chondroitin sulphate, dermatan sulphates, keratan sulphate and heparan sulphate.
TL;DR: Despite similarities in the morphology of cumulus oocyte complexes expanding in vivo and in vitro, it is found that the cECM of COCs which expand within intact follicles are more elastic and resistant to shear stress than the c ECM of those stabilized in vitro.
TL;DR: In this paper, a series of oligosaccharides from king crab cartilage chondroitin sulfate K were prepared for exhaustive digestion with testicular hyaluronidase.
Journal Article•
TL;DR: Sobue et al. as mentioned in this paper characterized the 2B1 antigen isolated from the conditioned medium of human malignant fibrous histiocytoma and found that immunological and biochemical properties are identical to those of a large chondroitin sulfate proteoglycan, PG-M/versican.
Abstract: 2B1 is a monoclonal antibody against a large proteoglycan isolated from human yolk sac tumor (M. Sobue et al. , Histochem. J., 21: 455–460, 1989). The antigen is expressed in a variety of embryonal tissues as well as most if not all malignant tumor tissues. However, the expression in normal adult tissues is limited to some tissues, such as the smooth muscle layers of the aorta. We characterized the 2B1 antigen isolated from the conditioned medium of human malignant fibrous histiocytoma and found that immunological and biochemical properties are identical to those of a large chondroitin sulfate proteoglycan, PG-M/versican. Partial amino acid sequences of peptides obtained from the core protein by V8 protease digestion and subsequent SDS-PAGE were detected in the reported amino acid sequence of human PG-M/versican with a complete identity. Furthermore, 2B1 was distinctly reactive to the expressed protein by transfection of the cDNA for the shortest form into mouse cells. The results indicate that the antigen is the PG-M core protein, and the epitope may be in one of the globular domains. It is thus likely that PG-M/versican is one of the extracellular matrix components characteristic of human malignant tumors.
TL;DR: The results suggest that the 6-O-sulfotransferases, in the absence of their natural substrates (keratan sulfate) may catalyze the sulfation of chondroitin 4-solfate as alternative substrate, and apparently, the K for galactosyltransferases involved in the synthesis of linkage regions of heparan sulfate and chond Detroitin sulfate are significantly lower than those participating in thehesis of keratan sulfates polymer.
TL;DR: The results suggest that lung epithelial cell interaction with environmental particles is mediated by distinct receptors and can lead to particle dependent cytokine responses.
Abstract: The A549 cell line was used to model in vitro the interaction of alveolar epithelium with environmental particulates. Confocal and electron microscopy demonstrated A549 binding and internalization of titanium dioxide (TiO2), iron oxide (Fe2O3), concentrated ambient air particulates (CAPs), and the fibrogenic particle alpha-quartz. Flow cytometry allowed quantitation of particle binding by measuring increased right angle light scatter (RAS) (TiO2) [40 micrograms/mL], Fe2O3 [100 micrograms/mL], alpha-quartz [200 micrograms/mL], or CAPs [40 micrograms/mL] fold increase RAS: 8.1 +/- 0.9, 4.3 +/- 0.4, 2 +/- 0.1, 1.6 +/- 0.1, respectively). With this quantitative assay, binding of particle was found to be calcium-dependent for TiO2 and Fe2O3 (% inhibition, 61.0 +/- 1.9, 40.0 +/- 5.6, respectively), while alpha-quartz binding was calcium-independent. A panel of polyanionic ligands known to inhibit scavenger-type receptors was used to identify binding mechanisms for environmental particulates. Both heparin and polyinosinic acid (polyI), but not the control polyanion chondroitin sulfate, caused marked inhibition of particulate binding by A549 cells (e.g., TiO2 [40 micrograms/mL] binding; polyI, heparin, and chondroitin sulfate: 73.8 +/- 3.5, 75.5 +/- 6.0, 7.5 +/- 6.7% inhibition, respectively; mean +/- SE, n > or = 4), indicating that scavenger receptor(s), albeit those distinct from the heparin-insensitive acetylated-LDL receptor, mediate particulate binding. The particulates ability to stimulate interleukin (IL-8) production in A549 cells was also tested. alpha-quartz, but not TiO2 or CAPs, caused a dose-dependent production of IL-8 (range 1-6 ng/mL), demonstrating a particle-specific spectrum of epithelial cell cytokine (IL-8) response. The results suggest that lung epithelial cell interaction with environmental particles is mediated by distinct receptors and can lead to particle dependent cytokine responses.
TL;DR: The differential effects of static compression and release on the biosynthesis of aggrecan, link protein, and hyaluronan are similar to the changes in the biosynthetic pathways that are affected in response to IL-1 treatment, suggesting that the response to static compression is not a general inhibition of cellular activity, but appears to be part of a specific transduction mechanism.
TL;DR: It is found that the lamina propria has diffuse staining of fibrillar components with keratan sulfate and decorin, which suggests that fibromodulin may be significant in normal vocal folds.
Abstract: We evaluated the proteoglycan composition of normal vocal folds using immunocytochemical techniques. Frozen sections of 14 normal cadaveric vocal folds were obtained within 12 hours of death and sectioned immediately. Vocal fold sections were stained with antibodies against keratan sulfate, chondroitin sulfate, heparan sulfate proteoglycan (HSPG), decorin, and hyaluronate receptor. We found that the lamina propria has diffuse staining of fibrillar components with keratan sulfate and decorin. Intense staining was observed in the vocal ligament area with keratan sulfate. The HSPG was localized to the basement membrane zone. Chondroitin sulfate, HSPG, and hyaluronate receptor were detected in the cytoplasm of interstitial cells with immunocytochemical characteristics of macrophages. The keratan sulfate distribution suggests that fibromodulin may be significant in normal vocal folds. Production of HSPG and probably versican occurs in macrophages and fibroblasts in the lamina propria.
TL;DR: The data support the possibility that one or more heparan sulfate proteoglycans may specifically modulate the interaction of α-dystroglycan with different extracellular matrix proteins in skeletal muscle.
TL;DR: A combination of immunological and molecular approaches, including cDNA cloning, showed that perlecan and BM-CSPG are distinct in core protein structure, although there are tissue-specific differences in their distribution.
TL;DR: Keratan sulfate modification of CD44 may play an important regulatory role in the broad spectrum of biological processes attributed to CD44, including normal development, tumor progression, and lymphocyte function.
TL;DR: The results indicate that human nonpancreatic secretory phospholipase A2 interacts with proteoglycans via their glycosaminoglycan moiety and that the enzyme activity may be modulated by the association of the enzyme and its substrate to the sulfated polysaccharides.
TL;DR: Binding of N-CAM to the immobilized neurocan core protein could be inhibited with all recombinant fragments containing chondroitin sulfate or major parts of the mucin-like central region of neurocan, however, a combination of globular and extended structures was required.
TL;DR: Heparan sulfate 2-sulfotransferase, which catalyzes the transfer of sulfate from adenosine 3′-phosphate 5′- phosphosulfate to position 2 of L-iduronic acid residue in heparan sulfate, was purified 51,700-fold to apparent homogeneity with a 6% yield from cultured Chinese hamster ovary cells.
TL;DR: The results now suggest that within the neuritic plaques of AD, there are at least four different classes of PGs present and these particular PGs/GAGs may also play distinct and important roles in neuritic plaque pathogenesis.
01 Jan 1996
TL;DR: In this article, the affinity of A2 for glycosaminoglycans from a heparan sulfate/chondroitin sulfate proteoglycan was investigated.
Abstract: Phospholipase A2 acting on low density lipoproteins in the extracellular arterial intima may form proinflammatory lipid mediators. Human nonpancreatic secretory phospholipase A2 has three regions that may associate with sulfated glycosaminoglycans. The apoB-100 molecule in low density lipoproteins also has glycosaminoglycan binding regions that could mediate its retention in the arterial intima. Here we report that human nonpancreatic phospholipase A2 isolated from a transfected cell line binds to glycosaminoglycans secreted by cultured human arterial smooth muscle cells. A gel mobility shift assay showed that the affinity of phospholipase A2 for glycosaminoglycans from a heparan sulfate/chondroitin sulfate proteoglycan was higher than for chondroitin sulfate glycosaminoglycans from a larger versican-like proteoglycan. Affinity chromatography confirmed these results. All glycosaminoglycans tested, at concentrations up to 100 mM, increased the activity of phospholipase A2 toward phosphatidylcholine liposomes. Above this concentration, heparan sulfate and heparin inhibited the enzyme. Heparin and chondroitin 6-sulfate increased phospholipase A2 activity on low density lipoproteins up to 4-fold at 100 mM, whereas heparan sulfate had no effect. The results indicate that human nonpancreatic secretory phospholipase A2 interacts with proteoglycans via their glycosaminoglycan moiety and that the enzyme activity may be modulated by the association of the enzyme and its substrate to the sulfated polysaccharides.
TL;DR: It is suggested that sulfated polyanions inhibit the invasion of erythrocytes by merozoites and cytoadherence of PRBC to endothelial cells by increasing negative repulsive charge and sterically interfering with the ligand-receptor interaction after binding to target cells.
Abstract: Sulfated proteoglycans have been shown to be involved in the binding of sporozoites of malaria parasites to hepatocytes. In this study, we have evaluated the effect of sulfated glycosaminoglycans on the invasion of erythrocytes by Plasmodium falciparum merozoites and cytoadherence of parasitized erythrocytes (PRBC) to endothelial cells. Invasion of erythrocytes by HB3EC-6 (an HB3 line selected for high binding to endothelial cells) was inhibited by dextran sulfate 500K, dextran sulfate 5K, sulfatides, fucoidan, and heparin but not by chondroitin sulfate A. With the exception of sulfatides, the invasion-inhibitory effect was not mediated by killing of parasites. Cytoadherence of HB3EC-6 to human microvascular endothelial cells (HMEC-1) and inhibited by these sulfated glycoconjugates. The highly sulfated dextran sulfate 500K had the highest inhibitory effect on both invasion and cytoadherence, whereas the positively charged protamine sulfate promoted cytoadherence. Because preincubation of PRBC with sulfated glycosaminoglycans and treatment of target cells with heparinase had no significant inhibition on cytoadherence, it is unlikely that sulfated glycoconjugates are used directly by endothelial cells as cytoadhesion receptors. In an vivo experiment, we found that the administration of dextran sulfate 500K to CBA/Ca mice infected with Plasmodium berghei ANKA reduced parasitemia and delayed the death associated with anemia. These observations suggest that sulfated polyanions inhibit the invasion of erythrocytes by merozoites and cytoadherence of PRBC to endothelial cells by increasing negative repulsive charge and sterically interfering with the ligand-receptor interaction after binding to target cells.
TL;DR: The major role of collagen in MT contrast of hyaline cartilage was confirmed and a higher cellular contribution to the MT effect was also demonstrated.
Abstract: PURPOSE: To elucidate the magnetization transfer (MT) effects of major components of hyaline cartilage. MATERIALS AND METHODS: The authors evaluated the MT effect of type II collagen and chondroitin sulfate phantoms (concentrations of 0.6%, 1.2%, 2.4%, 4.8%, 9.6%, and 19.2%), mass-cultured rat osteosarcoma-derived cells, and normal articular cartilage of the knee. RESULTS: The MT effect of collagen yielded a decrease in signal intensity of 10% (1.2% collagen) to 31% (19.2% collagen); the decrease varied linearly with collagen concentration. Chondroitin sulfate did not have a statistically significant MT effect. Cell pellets showed a decrease in signal intensity of 22%-26%, which was greater than that of 4.8% collagen. Normal articular cartilage of the knees showed a decrease in signal intensity of 38%-48%. CONCLUSION: The major role of collagen in MT contrast of hyaline cartilage was confirmed. In addition, a higher cellular contribution to the MT effect was also demonstrated.
TL;DR: Competition experiments showed that serglycin was as efficient as heparan sulfate in blocking the binding of [3H]chondroitin sulfate to PF4, whereas heparin was one order of magnitude more efficient.
Abstract: The major proteoglycan in macrophages and platelets is the chondroitin sulphate proteoglycan serglycin. To study the biological role of serglycin, its binding to secreted and cell-associated proteins from macrophages and blood platelets was examined. Affinity chromatography with serglycin-Sepharose and chondroitin sulphate-Sepharose was used to isolate proteoglycin-binding proteins from macrophages and platelets. Antibodies against human macrophage inflammatory protein-1 alpha (MIP-1 alpha) precipitated a 14-kDa 35S-methionine-labeled protein among the chondroitin sulfate binding proteins secreted from the macrophage-like U937 cells after stimulation. Two proteins from murine macrophage J774 cells with molecular masses of approximately 10 and 14 kDa were precipitated by an antiserum against the murine MIP-1 alpha. Protein sequencing of fragments obtained by trypsin digestion of a 14-kDa chondroitin sulfate-binding protein from cell extracts of stimulated U937 cells revealed 100% homology with lysozyme, a bacteriolytic enzyme. Fragment of one other protein with approximate molecular mass of 8 kDa showed high homology with bone morphogenetic protein. Inhibition studies showed that chondroitin 6-sulfate inhibited the bacteriolytic activity of lysozyme in a competitive manner more efficiently than heparin and chondroitin 4-sulphate. Amino-terminal sequencing of two proteins from platelet extracts that bound to serglycin-Sepharose revealed that they corresponded to multimeric forms of human platelet factor 4 (PE4). Chondroitin sulfate-Sepharose was shown to be equally efficient in retaining PF4 from platelet extracts as serglycin-Sepharose indicating that the glycosaminoglycan chains mediate the binding to PF4 in the intact proteoglycan molecule. Competition experiments showed that serglycin was as efficient as heparin sulfate in blocking the binding of [3H] chondrotin sulfate to PF4, whereas heparin was one order of magnitude more efficient. Affinity measurements using fluoresceinamine-labeled glycosaminoglycans showed that the affinity of heparin for PF4 is on the order of 30 nM, whereas chondroitin sulfate has an affinity of 260 nM. Both PF4, MIP-1 alpha, and lysozyme play important role in different types of inflammatory reactions. The interaction with serglycin may indicate that this proteoglycan is involved in the regulation of the inflammatory response.