H2O2 activates CD11b/CD18-dependent cell adhesion.
Treatment of monoblastoid U-937 cells with low concentrations of H2O2 caused adhesion of the cells to plastic. The H2O2 induced adhesion was rapid with a t1/2 of congruent to 6 min and was optimally stimulated by 100 microM H2O2 with an ED50 of congruent to 50 microM. The response to H2O2 closely resembled the adhesive response of U-937 cells to phorbol esters in its time dependency, requirement for extracellular Mg2+ and inhibition by cytochalasin B as well as inhibition by monoclonal antibodies against the leucocyte adhesion molecules CD11b and CD18. Phorbol ester treatment of U-937 cells stimulated the phosphorylation of at least three endogenous substrates, pp28, pp34 and pp43, of which pp28 and pp43 also responded to H2O2-treatment with increased 32P-incorporation. The results suggest that H2O2 might be a physiological modulator of leucocyte adhesion, possibly operating by activating protein kinase C.
Skoglund
G
G
Department of Physiological Chemistry, Karolinska Institute, Stockholm, Sweden.
Cotgreave
I
I
Rincon
J
J
Patarroyo
M
M
Ingelman-Sundberg
M
M
D000911:Antibodies, Monoclonal / Q000276:immunology; D000943:Antigens, Differentiation / Q000502:physiology*; D018821:CD18 Antigens; D002118:Calcium / Q000494:pharmacology; D002448:Cell Adhesion / Q000187:drug effects*; D002460:Cell Line; D003571:Cytochalasin B / Q000494:pharmacology; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D016177:Macrophage-1 Antigen; D008274:Magnesium / Q000494:pharmacology; D008562:Membrane Glycoproteins / Q000502:physiology*; D015240:Phorbol 12,13-Dibutyrate / Q000494:pharmacology; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation
D000911:Antibodies, Monoclonal; D000943:Antigens, Differentiation; D018821:CD18 Antigens; D016177:Macrophage-1 Antigen; D008562:Membrane Glycoproteins; D010750:Phosphoproteins; D015240:Phorbol 12,13-Dibutyrate; D003571:Cytochalasin B; D006861:Hydrogen Peroxide; D008274:Magnesium; D002118:Calcium