Effect of advanced glycosylation end products on the activity of integrins expressed on U937 cells.
Advanced glycosylation end products (AGEs) are formed both in healthy old persons and diabetic patients by nonenzymatic glycosylation. However, AGEs are supposed to be a major factor in the vascular damages associated with diabetes. The aim of this study was to assess the effect of AGEs on the activity of cell adhesion molecules expressed on lymphoid cells. Human serum albumin (HSA) was glycosylated in vitro and used as a specific stimulating agent with U937 cells. The effect of glc-HSA was evaluated by the method of homotypic adhesion and adhesion to immunoplate coated with fibronectin. Specific monoclonal antibodies against integrins and ICAM-1 were applied in these studies. It was shown that glc-HSA enhanced the homotypic adhesion. The latter was mediaced via beta2-integrins as the effect was recorded after 15 min. incubation. The homotypic adhesion for the cells treated with glc-HSA followed the same kinetics as the cells incubated with phorbol myriastate acetate, which was used as a positive control. An anti-CD18 antibody inhibited the adhesion of U937 cells which indicated that the glc-HSA had a positive effect on the activity of beta2-integrins. Treatment with glc-HSA did not interfere with the adhesion of the referent cells to fibronectin coated plate. Based on these results the conclusion was drawn that the advanced glycosylation end products have a differential effect on the activity of integrin subfamilies expressed on cells of monocyte-macrophage origin.
Ivanov
G
G
Department of Molecular Immunology, Institute of Biology and Immunology of Reproduction, Bulgarian Academy of Sciences, Sofia.
Kyurkchiev
S
S
D018821:CD18 Antigens / Q000378:metabolism; D002448:Cell Adhesion; D017127:Glycation End Products, Advanced / Q000378:metabolism*; D006031:Glycosylation; D006801:Humans; D019012:Integrin beta1 / Q000378:metabolism; D016023:Integrins / Q000378:metabolism*; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D017469:Receptors, Fibronectin / Q000378:metabolism; D012709:Serum Albumin / Q000378:metabolism; D014407:Tumor Cells, Cultured
D018821:CD18 Antigens; D017127:Glycation End Products, Advanced; D019012:Integrin beta1; D016023:Integrins; D017469:Receptors, Fibronectin; D012709:Serum Albumin; D018799:Intercellular Adhesion Molecule-1