Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.1.6.4 (chondroitinase)
2,039 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study deals with the development of the human conjunctival goblet cells. Fifty-six eyes of human embryos and fetuses ranging from 5 to 41 weeks of gestational stage were used. The distribution of glycosaminoglycans in the goblet cells was investigated with 1% alcian blue (pH 2.5) staining. For identifying the types of glycosaminoglycans, enzyme digestion methods were carried out with streptomyces hyaluronidase, chondroitinase AC, chondroitinase ABC, or sialidase (neuraminidase). At 9 weeks of gestational age, goblet cells appeared in the fornix region of the conjunctiva and extended toward the palpebral and bulbar regions. Histochemical studies with enzyme digestion methods revealed the existence of sialomucin in the goblet cells from 9 weeks. This finding suggested that the goblet cells first appeared in the fornix area, extending toward the palpebral region, then toward the bulbar region, and containing sialomucin from their early stage of development.
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PMID:Morphological and histochemical studies of goblet cells in developing human conjunctiva. 151 64

Previous investigations established that focal subretinal injections of neuraminidase, chondroitinase, and hyaluronidase in the rabbit lead to a diffuse loss of retinal adhesiveness beyond the site of injection. This loss of adhesiveness, measured by peeling of the retina immediately after enucleation, correlates with changes in the interphotoreceptor matrix (IPM), as monitored by lectin histochemistry. In this study, rabbits were evaluated during recovery of retinal adhesiveness after subretinal injections of neuraminidase and chondroitinase. Adhesion recovered steadily 5-20 days after chondroitinase injection. After administration of neuraminidase, adhesion remained low for approximately 14 days but recovered to normal by 20 days. The recovery of adhesiveness correlated closely with reestablishment of the normal distribution of peanut agglutinin-binding glycoconjugates in the IPM, one group of molecules thought to participate in retinal adhesion. Electroretinography and light microscopy showed no abnormalities in the retina or retinal pigment epithelium after recovery. These results suggest that IPM glycoconjugates participate in maintaining retinal adhesion.
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PMID:Recovery of retinal adhesion after enzymatic perturbation of the interphotoreceptor matrix. 154 77

A high performance liquid chromatography (HPLC) procedure suitable for the simultaneous determination of the molecular size and concentration of macromolecular hyaluronate and proteoglycans in synovial fluid has been developed. Irrigation of the equine tarsocrural joint with 20 ml physiological saline (PSS) caused a mild inflammation with an increase of proteoglycans in the synovial fluid over the baseline arthrocentesis control sample. Proteoglycan and hyaluronate in the synovial fluid did not interact to form hyaluronate-proteoglycan aggregates, but separated as distinct chromatographic peaks. This suggests that the cartilage derived proteoglycans in synovial fluid in the inflamed joint have been proteolytically cleaved from the non-covalent aggregates containing link protein and hyaluronate. Hyaluronidase digestion completely abolished the hyaluronate peak without affecting the proteoglycans. This seems to indicate that proteoglycan in synovial fluid is unable to interact with hyaluronate in synovial fluid to form cartilage type aggregates. Proteolytic degradation and the time dependent release into the synovial fluid of such digested proteoglycan also resulted from the intra-articular injection of methylprednisolone acetate into normal tarsocrural joints and joints irrigated with PSS. These proteoglycans were insensitive to hyaluronidase but may consist of a protein moiety with attached glycosaminoglycans, as suggested by their sensitivity to proteinase and keratanase/chondroitinase digestion. These observations with cartilage treated with methylprednisolone acetate and mildly stimulated articular cartilage are inconsistent with earlier work on osteoarthritic and rheumatoid articular cartilage and have interesting implications for the pathogenesis and for the therapeutic action of intraarticular corticosteroids. A rapid HPLC procedure applicable to unprocessed small volume samples of synovial fluid gives information simultaneously on hyaluronate and proteoglycan in synovial fluid which is not attainable with immunoradiometric or isotope tracer techniques. It therefore appears to be useful for the analysis of cartilage turnover and destruction in health and disease.
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PMID:Methylprednisolone acetate induced release of cartilage proteoglycans: determination by high performance liquid chromatography. 155 Apr 6

After immunization of mice with partially-purified heparan sulfate proteoglycan (HSPG) isolated from rat glomeruli, a monoclonal antibody (mAb JM-403) was obtained, which was directed against heparan sulfate (HS), the glycosaminoglycan side chain of HSPG. In ELISA it reacted with isolated human glomerular basement membrane (GBM) HSPG, HS and hyaluronic acid, but not with the core protein of human GBM HSPG, and not with chondroitin sulfate A and C, dermatan sulfate, keratan sulfate and heparin. Furthermore, it did not bind to laminin, collagen type IV or fibronectin. Specificity of JM-403 for HS was also suggested by results of inhibition studies, which found that intact HSPG and HS, but not the core protein, inhibited the binding of JM-403 to HS. In indirect immunofluorescence on cryostat sections of rat kidney, a fine granular to linear staining of the GBM was observed, along with a variable staining of the other renal basement membranes. Pretreatment of the sections with heparitinase completely prevented the binding of mAb JM-403, whereas pretreatment with chondroitinase ABC or hyaluronidase had no effect. The precise binding site of mAb JM-403 was investigated by indirect immunoelectron microscopy. It revealed a diffuse staining of the whole width of the GBM. One hour after intravenous injection of JM-403 into rats, the mAb was detected along the glomerular capillary wall in a fine granular pattern, which shifted towards a more mesangial localization after 24 hours. No binding was observed anymore by day 15. Intravenous injection induced a dose-dependent, transient and selective proteinuria that was maximal immediately after the injection.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:A monoclonal antibody against GBM heparan sulfate induces an acute selective proteinuria in rats. 159 46

Monoclonal antibodies were raised against human glial hyaluronate-binding protein (GHAP), a major CNS-specific glycoprotein known to bind hyaluronate in vitro. Frozen sections of dog and human spinal cord were digested with Streptomyces hyaluronidase in order to ascertain whether GHAP is bound to hyaluronate in vivo. Digestion with hyaluronidase, prior to staining of the sections by conventional indirect immunofluorescence, led to a drastic reduction in the intensity of the staining reaction. Chondroitinase ABC (protease-free) was also effective in bringing about the release of GHAP from tissue sections. This enzyme also degrades hyaluronate. The effects of the chondroitinase were completely reversed by the addition of 1 mM Zn2+, a known inhibitor of this enzyme. The intact protein was released into the soluble fraction of human brain homogenates by testicular hyaluronidase. An immunoreactive species of 70 kD was released into the soluble fraction of dog spinal cord homogenates by Streptomyces hyaluronidase. Dog GHAP was isolated from spinal cord by means of ion exchange and affinity chromatography. This protein bound efficiently to hyaluronate in vitro. Dog and human GHAP had identical isoelectric points and similar peptide maps but different molecular weights. Dog GHAP (70 kD) was larger than its human counterpart (60 kD). These findings imply that GHAP exists in association with hyaluronate in CNS white matter. Immunoelectron microscopy revealed that GHAP fills the space between myelin sheaths in dog spinal cord white matter. One is led to conclude therefore that an hyaluronate based extracellular matrix exists in CNS white matter.
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PMID:Extracellular matrix of central nervous system white matter: demonstration of an hyaluronate-protein complex. 171 74

Chondrons have recently been extracted from adult articular cartilages and techniques developed to study their structure and composition in isolation. This study introduces methods to immobilize isolated canine chondrons in thin layers of agarose gel for immunohistochemistry and future in vitro studies. An antibody to Type VI collagen which stained the chondron in suspension was used to successfully validate the system and its feasibility for immunoelectron microscopy. Monoclonal and polyclonal antibodies to a variety of epitopes on the proteoglycan molecule were tested on fresh and fixed plugs cored from chondron-agarose gels. Plugs were immunolabeled with peroxidase-diaminobenzidine before or after digestion with testicular hyaluronidase or chondroitinase ABC. Trypsin/chymotrypsin were used to challenge epitopes of the core protein. The results indicate that epitopes to keratan sulfate, chondroitin sulfate, hyaluronate binding region, and core protein are localized in the chondron. Consistent staining was found in the tail and interconnecting segments between chondrons, whereas staining of the pericellular matrix and capsule adjacent to the chondrocyte varied according to the enzyme pre-treatment employed. We conclude that isolated chondrons are rich in proteoglycan monomer, which is particularly concentrated in the tail and interconnecting segments of the chondron where it could function to protect and stabilize the chondrocyte.
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PMID:Chondrons from articular cartilage. (IV). Immunolocalization of proteoglycan epitopes in isolated canine tibial chondrons. 171 45

The synthesis and secretion of mucin-like high-molecular glycoprotein was studied in 2 human colon cancer cell lines that spontaneously differentiate in culture (Caco-2 and T84) and in 2 cell lines that do not spontaneously differentiate (LS174T and HT29). Mucin, quantitated by 3H-glucosamine labelling and chromatography on Sepharose CL-4B was found to be produced by all 4 cell lines. The mucinous nature of the labelled high-molecular glycoprotein was verified by enzymatic degradation treatments (heparinase, hyaluronidase, chondroitinase ABC, and N-glycanase), alkaline-borohydride treatment, inhibition of labelling by the glycosylation inhibitor benzyl-alpha-GalNAc, and by CsCl-density-gradient centrifugation. In all 4 cell lines, an inverse correlation of mucin synthesis with cell density was demonstrated. In Caco-2 cells, the spontaneous post-confluent enterocytic differentiation with increased brush-border enzyme expression was associated with a decrease in mucin synthesis and in the activities of polypeptidyl GalNAc transferase and beta 1,3-galactosyltransferase activity. Using cDNA probes for 2 distinct human intestinal mucins (MUC2 and MUC3), we found that all 4 colon cancer cell lines expressed mucin message, but the types of mucin mRNA expressed differed. These data indicate that mucin-like glycoproteins can be synthesized by cell lines derived from non-mucinous colon cancer, whether or not they undergo spontaneous differentiation in culture. These cell lines may serve as in vitro models for studying apomucin heterogeneity and control of mucin gene expression.
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PMID:Mucin synthesis and secretion in relation to spontaneous differentiation of colon cancer cells in vitro. 172 5

Hemodynamic forces continuously act on endothelial cell lining of blood vessels. Blood flow, perfusing pressure, and shear stress are known to induce the release of bioactive substances from the endothelium. Furthermore, coronary flow (CF) is a well-known stimulant of myocardial contraction. Our concern was whether other Ca(2+)-dependent responses like glycolytic flux (Gf) were also CF dependent. For this purpose, isolated guinea pig hearts were perfused with a medium containing 5 mM 3-[3H]glucose, and the 3H2O released during perfusion was measured as an index of Gf. Changes in CF within the 3- to 25-ml/min range resulted in linear increase of Gf. This stimulatory effect of CF was also observed in K(+)-arrested hearts. In addition, increasing shear stress on addition of dextran to the perfusing solution (5% and 10% wt/vol), while keeping CF constant, also stimulated Gf. We hypothesized that endothelial cell membrane glycocalyx may act as sensor to this stimuli. Thus one would expect that substances acting on these structures (enzymes heparinase, hyaluronidase, or chondroitinase or the lectin concanavalin A) when added to the perfusate might inhibit the CF-induced Gf. The results showed that concanavalin A and heparinase inhibited the Gf-CF-induced response, whereas chondroitinase and hyaluronidase had no effect. These findings suggest that there may be a selective effect of these agents affecting the Gf response to CF. Our data suggest that CF stimulates Gf through shearing forces acting on specific endothelial glycocalyx component(s). Therefore, deformation of these components could result in the transduction of physical signals into release of chemical messengers that act on the biochemical machinery of underlining parenchymal cells.
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PMID:Regulation of glycolytic flux by coronary flow in guinea pig heart. Role of vascular endothelial cell glycocalyx. 175 May 47

In order to visualize by light microscopy the glycosaminoglycans (GAGs) in the rat tongue mucosa, the tissue was fixed with cuprolinic-blue (CB)-aldehyde and the staining enhanced by autometallographic (AM) procedure. As other polyanions were also detected, enzymatic digestions with hyaluronidase, chondroitinase ABC and pronase were performed on these tissues in order to test the specificity of the staining. Chondroitinase ABC caused a dramatic decrease of silver grains in the lamina propria whereas hyaluronidase and pronase induced only discrete or no modification. This supported the concept that the GAGs visualized by CB and autometallography in this area as dermatan sulphate. The other polyanions (mostly DNA and RNA) seen in the epithelial layers were unaffected by these enzyme treatments.
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PMID:Autometallographic visualization of glycosaminoglycans in the tongue mucosa of rats using cuprolinic blue and enzymatic digestions. 186 53

We detected glomerular anionic sites in fixed, LR Gold-embedded ultra-thin tissue sections using cationic colloidal gold. Manual and computer-assisted quantitation were compared, and the influence of pH and glycosaminoglycan-degrading enzymes on site expression was examined. Both quantitation methods produced similar results. Alteration of pH within a narrow range (pH 2.5-3.0) markedly affected the staining pattern. At pH 2.5, epithelial and endothelial glycocalyx and regular sites restricted to the lamina rara externa were stained. At pH 3.0 and above, glycocalyx was unstained but intracellular and nuclear staining was present; glomerular basement membrane (GBM) and mesangial matrix sites were abundant. After chondroitinase ABC or hyaluronidase digestion, GBM staining was eliminated at pH 2.0 and reduced at pH 7.0 (p less than 0.001), suggesting that degraded sites are associated with chondroitin sulfate or hyaluronic acid. By contrast, prolonged heparitinase I digestion was ineffective at either pH. Digestion of purified substrates revealed crossreactivity of heparitinase towards chondroitin sulfate and of chondroitinase towards hyaluronic acid. Since tissue sites were reduced by chondroitinase but not heparitinase, we suggest that degradation is due to hyaluronidase activity of chondroitinase and the anionic sites are associated with hyaluronic acid. However, the influence of pH indicates that lamina rara externa sites are structurally distinct from other GBM anionic sites.
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PMID:Detection of glomerular anionic sites in post-embedded ultra-thin sections using cationic colloidal gold. 190 27


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