Evaluation of the role of mitogen-activated protein kinases in the expression of inducible nitric oxide synthase by IFN-gamma and TNF-alpha in mouse macrophages.
The expression of inducible nitric oxide synthase (iNOS) by macrophages is stimulated by coexposure to IFN-gamma and a number of stimuli, including TNF-alpha. Recent work has shown that TNF-alpha activates members of the mitogen-activated protein kinase family that subsequently trans-activate transcription factors implicated in the regulation of iNOS expression. The objective of this study was to systematically evaluate the role of: 1) p42mapk/erk2, 2) p46 c-Jun NH2-terminal kinase/stress-activated protein kinase (p46 JNK/SAPK), and 3) p38mapk in the induction of iNOS expression during costimulation of mouse macrophages with IFN-gamma and TNF-alpha. All three kinases were activated during costimulation with IFN-gamma and TNF-alpha. However, specific antagonism of the p42mapk/erk2 and p38mapk with PD98059 and SKF86002, respectively, had no effect on the induction of iNOS expression. In contrast, blockade of all three kinases with N-acetylcysteine completely blocked the induction of iNOS expression. In addition, specific antagonism of the JNK/SAPK upstream kinases MEKK (mitogen-activated protein kinase/extracellular signal-regulated kinase kinase kinase) and MKK4 (mitogen-activated protein kinase kinase 4) with dominant inhibitory mutants blocked transcriptional activation of the iNOS promoter in response to costimulation with IFN-gamma and TNF-alpha. Collectively, these findings support the involvement of p46 JNK/SAPK and its upstream kinases in regulating the induction of iNOS following ligation of the TNF-alpha receptor CD120a (p55) in the presence of IFN-gamma.
Chan
E D
ED
Department of Medicine, University of Colorado Health Sciences Center, Denver 80262, USA.
Winston
B W
BW
Uh
S T
ST
Wynes
M W
MW
Rose
D M
DM
Riches
D W
DW
D016475:3T3 Cells; D000818:Animals; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000502:physiology*; D004789:Enzyme Activation / Q000276:immunology; D004790:Enzyme Induction; D005786:Gene Expression Regulation / Q000276:immunology; D007371:Interferon-gamma / Q000502:physiology*; D048031:JNK Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; D048728:MAP Kinase Kinase Kinase 1; D008264:Macrophages / Q000201:enzymology*; D051379:Mice; D008809:Mice, Inbred C3H; D019950:Mitogen-Activated Protein Kinase 1 / Q000037:antagonists & inhibitors / Q000378:metabolism; D020929:Mitogen-Activated Protein Kinase Kinases; D020928:Mitogen-Activated Protein Kinases; D009154:Mutation; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000235:genetics; D052247:Nitric Oxide Synthase Type II; D011401:Promoter Regions, Genetic / Q000276:immunology; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors; D014409:Tumor Necrosis Factor-alpha / Q000502:physiology*; D048051:p38 Mitogen-Activated Protein Kinases
D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; D011505:Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D019950:Mitogen-Activated Protein Kinase 1; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D048728:MAP Kinase Kinase Kinase 1; C482578:Map3k1 protein, mouse; D048670:MAP Kinase Kinase 4; C482562:Map2k4 protein, mouse; D020929:Mitogen-Activated Protein Kinase Kinases