scholarly journals Glycosyl transferases in chondroitin sulphate biosynthesis. Effect of acceptor structure on activity

1985 ◽  
Vol 226 (3) ◽  
pp. 705-714 ◽  
Author(s):  
M W Gundlach ◽  
H E Conrad
Keyword(s):  
Hyaluronic Acid ◽  
Chick Embryo ◽  
Chondroitin Sulphate ◽  
Chain Elongation ◽  
Optimal Conditions ◽  
Ph Optimum ◽  
Microsomal Preparation ◽  
Glycosyl Transferases

The D-glucuronosyl (GlcA)- and N-acetyl-D-galactosaminyl (GalNAc)-transferases involved in chondroitin sulphate biosynthesis were studied in a microsomal preparation from chick-embryo chondrocytes. Transfer of GlcA and GalNAc from their UDP derivatives to 3H-labelled oligosaccharides prepared from chondroitin sulphate and hyaluronic acid was assayed by h.p.l.c. of the reaction mixture. Conditions required for maximal activities of the two enzymes were remarkably similar. Activities were stimulated 3.5-6-fold by neutral detergents. Both enzymes were completely inhibited by EDTA and maximally stimulated by MnCl2 or CoCl2. MgCl2 neither stimulated nor inhibited. The GlcA transferase showed a sharp pH optimum between pH5 and 6, whereas the GalNAc transferase gave a broad optimum from pH 5 to 8. At pH 7 under optimal conditions, the GalNAc transferase gave a velocity that was twice that of the GlcA transferase. Oligosaccharides prepared from chondroitin 4-sulphate and hyaluronic acid were almost inactive as acceptors for both enzymes, whereas oligosaccharides from chondroitin 6-sulphate and chondroitin gave similar rates that were 70-80-fold higher than those observed with the endogenous acceptors. Oligosaccharide acceptors with degrees of polymerization of 6 or higher gave similar Km and Vmax. values, but the smaller oligosaccharides were less effective acceptors. These results are discussed in terms of the implications for regulation of the overall rates of the chain-elongation fractions in chondroitin sulphate synthesis in vivo.

Cell adhesion and proteoglycans. I. The effect of exogenous proteoglycans on the attachment of chick embryo fibroblasts to tissue culture plastic and collagen

1979 ◽  
Vol 40 (1) ◽  
pp. 77-88
Author(s):  
P. Knox ◽  
P. Wells
Keyword(s):  
Tissue Culture ◽  
Hyaluronic Acid ◽  
Cell Adhesion ◽  
Chick Embryo ◽  
Structural Integrity ◽  
Chondroitin Sulphate ◽  
Cell Types ◽  
Tissue Culture Plastic ◽  
Keratan Sulphate ◽  
Covalently Linked

Proteoglycan was isolated from cartilage and freed from contaminating glycoproteins and hyaluronic acid. The macromolecule consists of a protein core covalently linked to a number of glycosaminoglycan side chains, namely chondroitin sulphate and keratan sulphate. This proteoglycan retards the attachment of a variety of cell types to tissue culture plastic and to collagen. Glycosaminoglycans alone, have no significant effect on rates of attachment. Similarly, trypsinized proteoglycan is without effect. It is concluded that the structural integrity of the proteoglycan macromolecule is essential for its effect on cell adhesion.

Neutrophil granulocytes: adhesion and locomotion on collagen substrata and in collagen matrices

1982 ◽  
Vol 58 (1) ◽  
pp. 455-467
Author(s):  
A.F. Brown
Keyword(s):  
Hyaluronic Acid ◽  
Chondroitin Sulphate ◽  
Three Dimensional ◽  
Neutrophil Granulocytes ◽  
Variable Properties ◽  
Collagen Fibres ◽  
Collagen Matrices ◽  
Coated Glass

Neutrophil granulocytes (PMNs) adhere poorly to and are unable to locomote on collagen-coated glass; they are able to attach to and invade three-dimensional matrices of collagen fibres. Invasion is largely independent of adhesion to the fibres, does not occur by proteolysis of the gel, and is not affected by the presence of fibronectin or chondroitin sulphate. Invasion is reduced by increasing the concentration of collagen in the gel or by the presence of hyaluronic acid. It is proposed that in both these situations there is physical obstruction of PMN movement. The ability to locomote through tissues of very variable properties in vivo is important in the role of the PMN in inflammation.

scholarly journals Initiation of chondroitin sulphate synthesis by β-d-galactosides. Substrates for galactosyltransferase II

1985 ◽  
Vol 227 (3) ◽  
pp. 805-814 ◽  
Author(s):  
J A Robinson ◽  
H C Robinson
Keyword(s):  
Chick Embryo ◽  
Glucuronic Acid ◽  
Chondroitin Sulphate ◽  
Acetate Incorporation ◽  
Glycosidic Linkage ◽  
Microsomal Preparation ◽  
Galactose Residue ◽  
Chain Synthesis ◽  
Chondroitin Sulphate Chain

beta-Galactosides were found to initiate chondroitin sulphate chain synthesis in chick-embryo cartilage in vitro and thereby relieve inhibition by cycloheximide of [3H]-acetate incorporation into chondroitin sulphate. beta-Galactosides with an apolar aglycan group such as phenyl O-beta-galactoside were active, whereas those with a charged or polar aglycan group such as pyridine 3-O-beta-galactoside or those with sulphur instead of oxygen in the glycosidic linkage (phenyl beta-thiogalactoside) were not. beta-Galactosides also serve as substrates for microsomal galactosyltransferase activity from chick-embryo cartilage. Phenyl O-beta-galactoside and pyridine 3-O-beta-galactoside were effective substrates for this enzyme, but phenyl S-beta-thiogalactoside and pyridine 2-S-beta-thiogalactoside were only slightly active. This galactosyltransferase was shown to be a separate enzyme from galactosyltransferase I, which catalyses transfer of galactose from UDP-galactose to beta-xylosides. It is proposed that the enzyme catalysing this reaction is galactosyltransferase II, responsible for transfer of the second galactose residue of the chondroitin sulphate linkage oligosaccharide. No transfer of glucuronic acid from UDP-glucuronic acid to beta-galactosides, catalysed by the microsomal preparation could be detected.

scholarly journals Occurrence of ornithine decarboxylase and polyamines in cartilage

1977 ◽  
Vol 162 (2) ◽  
pp. 347-350 ◽  
Author(s):  
P D Conroy ◽  
D M Simms ◽  
J J Pointon
Keyword(s):  
Chick Embryo ◽  
Ornithine Decarboxylase ◽  
Costal Cartilage ◽  
Decarboxylase Activity ◽  
Ph Optimum ◽  
Tissue Protein ◽  
Ornithine Decarboxylase Activity ◽  
Body Tissues ◽  
Human Foetuses

The activity of ornithine decarboxylase was investigated in cartilage from chick embryos, rabbits, rats and human foetuses. The enzyme activity in these cartilages was of the same order as the detected in other body tissues. Ornithine decarboxylase activity in chick-embryo cartilage and liver was the same when compared on the basis of total soluble tissue protein. The cartilage enzyme exhibited a pH optimum of 6.5 and a Km for ornithine of 0.16mM. Ornithine decarboxylase activity in chick-embryo pelvic leaflets was maintained at the value in vivo for up to 22h when the isolated tissue was incubated in a modified Waymouth's medium (MB 752/1) at 37 degrees C. After addition of cycloheximide to the incubation medium, ornithine decarboxylase activity declined, with a half-life of 40 min. The concentrations of the polyamines spermidine and spermine in chick-embryo pelvic cartilage and rabbit costal cartilage were of the same order as the concentrations detected in other tissues.

Healing of Circular Defects in the Rabbit Medial Meniscus Can Occur Spontaneously and Is not Improved by Intra-Articular Hyaluronic Acid

1996 ◽  
Vol 09 (02) ◽  
pp. 60-5 ◽  
Author(s):  
N. Hope ◽  
P. Ghosh ◽  
S. Collier
Keyword(s):  
Hyaluronic Acid ◽  
Medial Meniscus ◽  
Chondroitin Sulphate ◽  
Rabbit Model ◽  
Type Ii Collagen ◽  
Type Ii ◽  
Keratan Sulphate ◽  
Meniscal Healing ◽  
Meniscus Healing ◽  
Made In

SummaryThe aim of this study was to determine the effects of intra-articular hyaluronic acid on meniscal healing. Circular defects, 1.0 mm in diameter, were made in the anterior third of the medial meniscus in rabbits. In one joint, 0.4 ml hyaluronic acid (Healon®) was instilled, and in the contralateral (control) joint, 0.4 ml Ringer’s saline. Four rabbits were killed after four, eight and 12 weeks and the menisci examined histologically. By eight weeks most of the lesions had healed by filling with hyaline-like cartilage. Healing was not improved by hyaluronic acid treatment. The repair tissue stained strongly with alcian blue, and the presence of type II collagen, keratan sulphate, and chondroitin sulphate was demonstrated by immunohistochemical localisation. In contrast to the circular defects, longitudinal incisions made in the medial menisci of a further six rabbits did not show any healing after 12 weeks, indicating that the shape of the lesion largely determined the potential for healing.The effect of hyaluronic acid on meniscal healing was tested in a rabbit model. With one millimeter circular lesions in the medial meniscus, healing by filling with hyalinelike cartilage was not significantly affected by the application of hyaluronic acid intra-articularly at the time of surgery, compared to saline controls, as assessed histologically four, eight and 12 weeks after the operation.

Studies on Chick Embryo Thrombocytes

1963 ◽  
Vol 09 (02) ◽  
pp. 291-299 ◽  
Author(s):  
Helge Stalsberg ◽  
Hans Prydz
Keyword(s):  
Chick Embryo ◽  
Bleeding Time ◽  
In Vivo Microscopy ◽  
Cut Edge ◽  
Vessel Lumen ◽  
Cellular Constituent

SummaryThe formation of hemostatic plugs were studied in the chick embryo through in vivo microscopy, in sections of hemostatic plugs and by measurements of primary bleeding time. Thrombocytes were found to be their only cellular constituent. Ability to form adequate hemostatic plugs appeared rather abruptly in embryos of stages 16-17 and coincided with an increase in thrombocyte precursors (stages III and IV).The thrombocytes initially adhere to the cut edge of the vessel. The extension of the hemostatic plug into the vessel lumen is a secondary step in plug development.

scholarly journals THE INFLUENCE OF CORTISONE ON EXPERIMENTAL VIRAL INFECTION

1966 ◽  
Vol 123 (2) ◽  
pp. 309-325 ◽  
Author(s):  
K. Marilyn Smart ◽  
Edwin D. Kilbourne
Keyword(s):  
Chick Embryo ◽  
Inflammatory Response ◽  
Chorioallantoic Membrane ◽  
Allantoic Fluid ◽  
Influenza Viruses ◽  
Present System ◽  
Interferon Production ◽  
Hydrocortisone Administration ◽  
Experimental Viral Infection

A comparative study was undertaken of the pathogenesis of infection of the allantoic sac of the chick embryo with three influenza viruses of differing virulence, and of the influence of hydrocortisone on the course of infection. Judged on the basis of earlier onset and greater degree of inflammatory response and diminished survival time of infected embryos, Mel. and Lee viruses were markedly more virulent than PR8, despite the earlier appearance of virus in PR8-infected embryos. Interferon appeared first and in greater quantity in the allantoic fluid of Lee-infected embryos and latest with PR8 infection. Thus, there was no correlation of avirulence and better interferon production with the viruses under study in the present system. Furthermore, evidence obtained suggested that Lee virus ("virulent") was most susceptible to interferon action, and also that viral synthesis in the chorioallantoic membrane with PR8 ("avirulent") persisted after the appearance of interferon. The injection of hydrocortisone within 2 hr of the initiation of infection delayed the synthesis of all three viruses; had no significant effect upon the inflammatory response; and transiently inhibited the synthesis of interferon, while prolonging the survival of Lee- and Mel.-infected embryos. Late administration of hydrocortisone suppresses both the inflammatory response and the production of interferon. Only in the case of Lee virus infection did hydrocortisone administration lead to augmentation of final yields of virus with the low infection multiplicity employed in the present experiments. It is postulated that Lee virus is a better inducer of interferon because its infectivity in vivo is more rapidly inactivated. As a consequence synthesis of Lee virus is more under the control of endogenous interferon than is the case with PR8 or Mel. virus. Therefore, inhibition of interferon synthesis with hydrocortisone has a greater influence on final yields of Lee virus.

scholarly journals Secreted KIAA1199 promotes the progression of rheumatoid arthritis by mediating hyaluronic acid degradation in an ANXA1-dependent manner

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Wei Zhang ◽  
Guoyu Yin ◽  
Heping Zhao ◽  
Hanzhi Ling ◽  
Zhen Xie ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Hyaluronic Acid ◽  
Dependent Manner ◽  
Collagen Induced Arthritis ◽  
Intracellular Degradation ◽  
Main Pathway ◽  
First Time

AbstractIn inflamed joints, enhanced hyaluronic acid (HA) degradation is closely related to the pathogenesis of rheumatoid arthritis (RA). KIAA1199 has been identified as a hyaladherin that mediates the intracellular degradation of HA, but its extracellular function remains unclear. In this study, we found that the serum and synovial levels of secreted KIAA1199 (sKIAA1199) and low-molecular-weight HA (LMW-HA, MW < 100 kDa) in RA patients were significantly increased, and the positive correlation between them was shown for the first time. Of note, treatment with anti-KIAA1199 mAb effectively alleviated the severity of arthritis and reduced serum LMW-HA levels and cytokine secretion in collagen-induced arthritis (CIA) mice. In vitro, sKIAA1199 was shown to mediate exogenous HA degradation by attaching to the cell membrane of RA fibroblast-like synoviosytes (RA FLS). Furthermore, the HA-degrading activity of sKIAA1199 depended largely on its adhesion to the membrane, which was achieved by its G8 domain binding to ANXA1. In vivo, kiaa1199-KO mice exhibited greater resistance to collagen-induced arthritis. Interestingly, this resistance could be partially reversed by intra-articular injection of vectors encoding full-length KIAA1199 instead of G8-deleted KIAA119 mutant, which further confirmed the indispensable role of G8 domain in KIAA1199 involvement in RA pathological processes. Mechanically, the activation of NF-κB by interleukin-6 (IL-6) through PI3K/Akt signaling is suggested to be the main pathway to induce KIAA1199 expression in RA FLS. In conclusion, our study supported the contribution of sKIAA1199 to RA pathogenesis, providing a new therapeutic target for RA by blocking sKIAA1199-mediated HA degradation.

Sign in / Sign up

Export Citation Format

Share Document