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Protein kinase C and tyrosine kinase pathways regulate lipopolysaccharide‐induced nitric oxide synthase activity in RAW 264.7 murine macrophages
Author(s) -
Paul Andrew,
Pendreigh Robert H,
Plevin Robin
Publication year - 1995
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1995.tb13252.x
Subject(s) - protein kinase c , nitric oxide synthase , protein kinase a , tyrosine kinase , chemistry , microbiology and biotechnology , lipopolysaccharide , nitric oxide , biochemistry , biology , kinase , signal transduction , endocrinology
1 In RAW 264.7 macrophages, lipopolysaccharide (LPS) and γ‐interferon (IFNγ) alone or in combination stimulated the induction of nitric oxide synthase (iNOS) activity and increased the expression of the 130 kDa isoform of NOS. 2 LPS‐induced NOS activity was reduced by incubation with CD14 neutralising antibodies and abolished in macrophages deprived of serum. 3 LPS stimulated a small increase in protein kinase C (PKC) activity in RAW 264.7 macrophages which was dependent on the presence of serum. However, IFNγ did not potentiate LPS‐stimulated PKC activity. 4 The protein kinase C inhibitor, Ro‐318220, abolished both LPS‐ and IFNγ‐stimulated protein kinase C activity and the induction of NOS activity. 5 LPS‐ and IFNγ‐induced NOS activity was reduced by the tyrosine kinase inhibitor genestein. Genestein also reduced LPS‐stimulated protein kinase C activity but did not affect the response to the protein kinase C activator, tetradecanoylphorbol acetate (TPA). 6 Nicotinamide, an inhibitor of poly‐ADP ribosylation, abolished LPS‐ and IFNγ‐induced NOS activity. 7 Brefeldin A, an inhibitor of a factor which stimulates nucleotide exchange activity on the 21 kDa ADP‐ribosylation factor, ARF, reduced LPS‐ and IFNγ‐induced NOS activity by approximately 80%. 8 These results suggest the involvement of protein kinase C, tyrosine kinase and ploy‐ADP ribosylation pathways in the regulation of the induction of nitric oxide synthase in RAW 264.7 macrophages by LPS and IFNγ.