title: Augmentation of c-fos mRNA expression by activators of protein kinase C in fresh, terminally differentiated resting macrophages.
abstract: Expression of c-fos mRNA was investigated in fresh, normal peritoneal macrophages (M phi), which are terminally differentiated, nonproliferating cells. The levels of c-fos mRNA were dramatically increased by stimulation with phorbol myristate acetate (PMA), calcium ionophore, or 1-oleoyl-2-acetoyl glycerol (OAG). Induction of c-fos mRNA by all the above agents followed similar kinetics, with a peak of mRNA 30 min after stimulation. These results demonstrate that c-fos mRNA can be augmented in fresh, terminally differentiated cells. Since the stimuli increasing c-fos mRNA are direct or indirect activators of protein kinase C, our data suggest that in M phi c-fos mRNA is controlled by protein kinase C activation. PMA, calcium ionophore, and OAG were biologically active in M phi. PMA and calcium ionophore induced respiratory burst and tumoricidal activity, respectively, whereas OAG and PMA were chemotactic for M phi. Interferons beta and gamma, potent M phi activators eliciting tumoricidal activity, did not alter the levels of c-fos mRNA. These results indicate that c-fos mRNA augmentation is a stimulus-specific rather than a function-specific response connected to activation of protein kinase C.
mesh_terms: D000001:Calcimycin / Q000494:pharmacology; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D004075:Diglycerides / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D005786:Gene Expression Regulation / Q000187:drug effects; D007370:Interferon Type I / Q000494:pharmacology; D007371:Interferon-gamma / Q000494:pharmacology; D007700:Kinetics; D008264:Macrophages / Q000187:drug effects / Q000502:physiology*; D011493:Protein Kinase C / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D011519:Proto-Oncogenes; D012333:RNA, Messenger / Q000235:genetics; D013481:Superoxides / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D004075:Diglycerides; D007370:Interferon Type I; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D013481:Superoxides; D000001:Calcimycin; D007371:Interferon-gamma; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate