Involvement of NF-kappa B in the regulation of cyclooxygenase-2 protein expression in LPS-stimulated J774 macrophages

We investigated the involvement of NF-kappa B in the regulation of COX-2 protein expression and prostaglandin production in LPS-stimulated J774 macrophages. Incubation of J774 cells with LPS (1 mu g/ml) for 24 h caused an increase of COX-2 protein expression and accumulation of both PGE(2) and 6-keto-PGF(1 alpha), in the cell culture medium, Ammonium pyrrolidinedithiocarbamate (APDC, 0.1, 1, 10 mu M) and N-alpha-p-tosyl-L-lysine chloromethylketone (TLCK, 1, 10, 100 mu M),two inhibitors of NF-kappa B activation, suppressed in a concentration-dependent manner both LPS-induced COX-2 protein expression and prostanoid generation, Moreover, APDC and TLCK both inhibited the LPS-induced increase of NF-kappa B DNA binding activity and prevented I kappa B-alpha degradation, Our results show for the first time that NF-kappa B is involved in COX-2 protein expression in LPS-stimulated J774 macrophages and suggest that inhibitors of NF-kappa B activation may represent a useful tool for the pharmacological control of inflammation. (C) 1997 Federation of European Biochemical Societies.