scholarly journals Detection of age-related changes in the distributions of keratan sulfates and chondroitin sulfates in developing chick limbs: an immunocytochemical study

Development ◽  
1989 ◽  
Vol 106 (4) ◽  
pp. 657-663
Author(s):  
J.M. Sorrell ◽  
B. Caterson

A panel of four separate monoclonal antibodies, all known to specifically recognize epitopes on keratan sulfate glycosaminoglycans, were employed in an immunocytochemical study of developing chick hind limbs. In addition, two monoclonal antibodies specific for epitopes on chondroitin/dermatan sulfate glycosaminoglycans were employed on equivalent sections to determine the degree of colocalization of keratan and chondroitin/dermatan sulfates. The spatial distributions of keratan sulfate and chondroitin/dermatan sulfate differed to some extent. In younger embryos, high extracellular concentrations of keratan sulfate occurred in joints and articular cartilages, with diminishing amounts being present in epiphyseal and diaphyseal regions. The high concentration of keratan sulfate in joints and articular cartilage corresponded to equally high concentration of chondroitin-6 sulfate. With advancing age, the above mentioned distribution was modified, most notably by increased amounts of keratan sulfate within diaphyseal regions. Finally, the use of four different anti-keratan sulfate monoclonal antibodies made it possible to compare keratan sulfate epitope expression. Differences in keratan sulfate epitopes were noted in some regions of bones, mostly in diaphyseal regions of younger bones and epiphyseal regions of older bones. This pattern of keratan sulfate expression suggests that different types of keratan sulfate may be present and their expression may be developmentally regulated.

1981 ◽  
Vol 90 (1) ◽  
pp. 32-39 ◽  
Author(s):  
L van de Water ◽  
S Schroeder ◽  
E B Crenshaw ◽  
R O Hynes

It has been suggested that fibronectin plays a role in clearing particles from the circulation by promoting binding to phagocytes of the reticuloendothelial system. By use of a well-defined system to investigate the possible opsonic role of fibronectin, we have studied the uptake of gelatin-coated latex particles by a murine macrophage cell line (P388D1). Fibronectin promotes binding of gelatin-coated beads to these cells in both suspension and monolayer cultures. In both cases there is a requirement for heparin as a cofactor. Other glycosaminoglycans (chondroitin sulfates A and C, dermatan sulfate, and keratan sulfate) were inactive, whereas heparan sulfate was somewhat active. Proof that beads were actually endocytosed was obtained by electron microscopy, which showed beads internalized in membrane-bounded vesicles, and by immunofluorescence analyses, using antibodies to fibronectin to stain external beads. Two rapid assays for the opsonic activity of fibronectin were developed based on differential centrifugation of cell-associated beads and on the immunofluorescence procedure. Binding and endocytosis were time- and temperature-dependent and varied with the amount of gelatin on the beads and with the concentrations of fibronectin and heparin added, and could be inhibited by F(ab')2 antifibronectin. These studies provide a sound basis for a detailed analysis of the interaction of fibronectin with the cell surface and of its involvement in endocytosis.


1991 ◽  
Vol 260 (5) ◽  
pp. H1667-H1673 ◽  
Author(s):  
K. Ley ◽  
M. Cerrito ◽  
K. E. Arfors

Before firm adhesion, leukocytes roll slowly along the walls of small venules at velocities ranging from 0.7 to 36% of mean blood flow velocity. To investigate the nature of the adhesive process underlying leukocyte rolling, synthetic (dextran sulfate) and naturally occurring sulfated polysaccharides (heparin, chondroitin sulfates, keratan sulfate, and heparan sulfate) were infused via glass micropipettes into the lumen of small venules (20–60 microns diam) of the rabbit mesentery. Leukocyte rolling was observed and quantified using both transmitted light and incident fluorescence intravital microscopy. Rolling leukocytes accounted for 27–80% of total leukocyte flux, exhibiting a wide range of individual velocities (0.01–0.84 mm/s) with a mean value of 4% of centerline velocity. Dextran sulfate (Mr 500,000) inhibited leukocyte rolling very effectively [half-effective concentration (ED50) approximately 10 micrograms/ml] and was able to almost completely abolish rolling at 500 micrograms/ml. Heparin (ED50 approximately 50 micrograms/ml), chondroitin 6-sulfate C (ED50 approximately 500 micrograms/ml), and heparan sulfate (ED50 approximately 5 mg/ml) also reduced leukocyte rolling. At 5 mg/ml, chondroitin 4-sulfate B (dermatan sulfate) was marginally effective, but chondroitin 4-sulfate A and keratan sulfate were ineffective. The present data suggest that an adhesion receptor-ligand system distinct from the leukocyte integrins may be underlying transient leukocyte adhesion (rolling). Endothelial glycoproteins or proteoglycans containing sulfated side chains may be involved in mediating this adhesive process.


2021 ◽  
Vol 14 (2) ◽  
pp. 92
Author(s):  
Panagiotis Gklinos ◽  
Miranta Papadopoulou ◽  
Vid Stanulovic ◽  
Dimos D. Mitsikostas ◽  
Dimitrios Papadopoulos

Over the last 30 years the role of monoclonal antibodies in therapeutics has increased enormously, revolutionizing treatment in most medical specialties, including neurology. Monoclonal antibodies are key therapeutic agents for several neurological conditions with diverse pathophysiological mechanisms, including multiple sclerosis, migraines and neuromuscular disease. In addition, a great number of monoclonal antibodies against several targets are being investigated for many more neurological diseases, which reflects our advances in understanding the pathogenesis of these diseases. Untangling the molecular mechanisms of disease allows monoclonal antibodies to block disease pathways accurately and efficiently with exceptional target specificity, minimizing non-specific effects. On the other hand, accumulating experience shows that monoclonal antibodies may carry class-specific and target-associated risks. This article provides an overview of different types of monoclonal antibodies and their characteristics and reviews monoclonal antibodies currently in use or under development for neurological disease.


1983 ◽  
Vol 65 (2) ◽  
pp. 155-157 ◽  
Author(s):  
T. G. Cotter ◽  
K. O'Malley

1. Neutrophils from drug-free elderly subjects produced approximately 50% less cyclic AMP in response to isoprenaline than did neutrophils from young subjects. A significant difference in basal cyclic AMP levels was also evident (elderly 2.8 ± 0.37; young 4.9 ± 0.36 pmol of cAMP/107 cells; P < 0.05). 2. With a range of anti-neutrophil monoclonal antibodies no evidence of age-related neutrophil population heterogeneity was found. 3. These findings indicate that the age-related decline in β-adrenoceptor responsiveness is not due to changes in the neutrophil population. 4. The present results support the hypothesis that there is a generalized decline in β-adrenoceptor-mediated responsiveness in the elderly.


Sign in / Sign up

Export Citation Format

Share Document