title: Regulation of ICAM-1 expression in mouse macrophages.
abstract: In a mouse model of silica (SI) induced lung injury, SI exposure increases expression of intercellular adhesion molecule-1 (ICAM-1) on lung (alveolar/interstitial) macrophages and alveolar type II epithelial cells. To investigate the regulation of SI induced ICAM-1 expression on mouse macrophages, freshly isolated macrophages (alveolar, peritoneal) and macrophage cell lines (MH-S, RAW 264.7) were evaluated for ICAM-1 expression elicited by the particle silica (alpha quartz; 20 microg/ml; 6 microg/cm2) or the inflammatory cytokine, TNFalpha (20 ng/ml). TNFalpha significantly increased ICAM-1 expression in all cell types whereas SI elicited an increase in peritoneal macrophages (PM) and the cell line, MH-S. This pattern of increased expression was confirmed by immunocytochemistry. To investigate the regulation of ICAM-1 expression, PM were incubated with SI, TNFalpha or media concomitantly with anti-TNFalpha antibody, the antioxidant, NAC, or the iNOS synthase inhibitor, L-NAME. Both anti-TNFalpha and NAC, but not L-NAME, inhibited elicited (TNFalpha, SI) as well as constitutive (media) ICAM-1 expression. These data demonstrate that both inflammatory cytokines and inorganic particles can increase ICAM-1 expression on mouse macrophages and that this expression is mediated, in part, by TNFalpha and reactive oxygen species.
authors.affiliation: Department of Pharmaceutical Sciences, University of Connecticut, Storrs 06269, USA.
authors.forename: A K
authors.initials: AK
authors.lastname: Hubbard
authors.forename: C
authors.initials: C
authors.lastname: Giardina
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D005260:Female; D016166:Free Radical Scavengers / Q000494:pharmacology; D018799:Intercellular Adhesion Molecule-1 / Q000096:biosynthesis*; D008264:Macrophages / Q000737:chemistry*; D016676:Macrophages, Alveolar / Q000737:chemistry; D017737:Macrophages, Peritoneal / Q000737:chemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D012822:Silicon Dioxide / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology / Q000494:pharmacology
chemical_list: D000911:Antibodies, Monoclonal; D016166:Free Radical Scavengers; D014409:Tumor Necrosis Factor-alpha; D018799:Intercellular Adhesion Molecule-1; D012822:Silicon Dioxide; D000111:Acetylcysteine