scholarly journals Phagocytosis of gelatin-latex particles by a murine macrophage line is dependent on fibronectin and heparin.

1981 ◽  
Vol 90 (1) ◽  
pp. 32-39 ◽  
Author(s):  
L van de Water ◽  
S Schroeder ◽  
E B Crenshaw ◽  
R O Hynes
Keyword(s):  
Dermatan Sulfate ◽  
Keratan Sulfate ◽  
Reticuloendothelial System ◽  
Murine Macrophage ◽  
Temperature Dependent ◽  
Opsonic Activity ◽  
Latex Particles ◽  
Chondroitin Sulfates ◽  
Rapid Assays

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.

Sulfated polysaccharides inhibit leukocyte rolling in rabbit mesentery venules

1991 ◽  
Vol 260 (5) ◽  
pp. H1667-H1673 ◽  
Author(s):  
K. Ley ◽  
M. Cerrito ◽  
K. E. Arfors
Keyword(s):  
Heparan Sulfate ◽  
Dextran Sulfate ◽  
Dermatan Sulfate ◽  
Leukocyte Adhesion ◽  
Keratan Sulfate ◽  
Mean Value ◽  
Sulfated Polysaccharides ◽  
Leukocyte Rolling ◽  
Chondroitin Sulfates ◽  
Wide Range

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.

Effect of Sulfate Content of Biomacromolecules on the Crystallization of Calcium Carbonate

2001 ◽  
Vol 711 ◽  
Author(s):  
José I. Arias ◽  
Carolina Jure ◽  
Juan P. Wiff ◽  
María S. Fernández ◽  
Víctor Fuenzalida ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Dermatan Sulfate ◽  
Keratan Sulfate ◽  
Organic Matrix ◽  
Sulfate Proteoglycan ◽  
Sulfate Content ◽  
Dermatan Sulfate Proteoglycan ◽  
Chicken Eggshell ◽  
Natural Composite

ABSTRACTNatural composite bioceramics such as bone, teeth, carapaces and shells contain organic and inorganic moieties, with the organic matrix components directly involved in the precise formation of these structures. We have previously shown that chicken eggshell contains two main sulfated polymers (proteoglycans), referred to as mammillan and ovoglycan which are involved in nucleation and growth of the eggshell calcite crystals. They differ on their anionic properties due to the carboxylate and sulfate content of their glycosaminoglycan component. Based on biological and biochemical evidences, the putative role of mammillan, a keratan sulfate proteoglycan, is in the nucleation of the first calcite crystals, while that of ovoglycan, a dermatan sulfate proteoglycan, is to regulate the growth and orientation of the later forming crystals of the chicken eggshell. In this communication, a systematic study of the influence of variable concentrations of glycosaminoglycans differing in their sulfation status on the morphology, size and number of calcium carbonate crystals after crystallization on microbridges from a calcium chloride solution under an atmosphere of ammonium carbonate at different pH is presented. Depending on the pH and concentration, the variation of sulfation status drastically changed the morphology, size and number of calcite crystals. The produced calcite particles with various morphologies are promising candidates for some novel materials with desirable shape- and texture-depending properties.

Reticuloendothelial system function and humoral factor deficiency following acute hemorrhage

1978 ◽  
Vol 56 (2) ◽  
pp. 299-303 ◽  
Author(s):  
Freddie K. Carr ◽  
Daniel J. Loegering
Keyword(s):  
Time Course ◽  
Reticuloendothelial System ◽  
Phagocytic Index ◽  
Opsonic Activity ◽  
Acute Hemorrhage ◽  
Shed Blood ◽  
Factor Deficiency ◽  
Carbon Clearance ◽  
Close Temporal Relationship

The present study has shown that following acute hemorrhage (equivalent to 3% body weight withdrawn over 20 min) in the rat, there is a large reduction (56% of control) in circulating α-2-glycoprotein opsonic activity. The reduction in this plasma opsonic activity was near maximal by the completion of blood withdrawal and was maintained throughout a 2-h hypotension period. There was no trend toward recovery of the opsonic activity when evaluated 15 min following reinfusion of shed blood in animals that were hypotensive for 0, 30, and 120 min. Reticuloendothelial system (RES) phagocytic function, as assessed from the carbon clearance rate (phagocytic index) following reinfusion of the shed blood, was depressed in animals that were hypotensive for 0, 30, and 120 min. Thus, phagocytic index followed a time course similar to the depression of opsonic activity. The observed close temporal relationship between α-2-glycoprotein opsonic deficiency and depression of RES clearance further supports the possible role of a humoral opsonic deficiency in mediating the RES phagocytic depression during circulatory shock.

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
Keyword(s):  
Monoclonal Antibodies ◽  
Dermatan Sulfate ◽  
Keratan Sulfate ◽  
Immunocytochemical Study ◽  
High Concentration ◽  
Developmentally Regulated ◽  
Chondroitin Sulfates ◽  
Hind Limbs ◽  
Age Related ◽  
Different Types

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.

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