Abstract
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.
Publication types
-
Research Support, Non-U.S. Gov't
-
Research Support, U.S. Gov't, P.H.S.
MeSH terms
-
3T3 Cells
-
Animals
-
Calcium-Calmodulin-Dependent Protein Kinases / antagonists & inhibitors
-
Calcium-Calmodulin-Dependent Protein Kinases / metabolism
-
Calcium-Calmodulin-Dependent Protein Kinases / physiology*
-
Enzyme Activation / immunology
-
Enzyme Induction
-
Gene Expression Regulation / immunology
-
Interferon-gamma / physiology*
-
JNK Mitogen-Activated Protein Kinases
-
MAP Kinase Kinase 4*
-
MAP Kinase Kinase Kinase 1*
-
Macrophages / enzymology*
-
Mice
-
Mice, Inbred C3H
-
Mitogen-Activated Protein Kinase 1 / antagonists & inhibitors
-
Mitogen-Activated Protein Kinase 1 / metabolism
-
Mitogen-Activated Protein Kinase Kinases*
-
Mitogen-Activated Protein Kinases*
-
Mutation
-
Nitric Oxide Synthase / antagonists & inhibitors
-
Nitric Oxide Synthase / biosynthesis*
-
Nitric Oxide Synthase / genetics
-
Nitric Oxide Synthase Type II
-
Promoter Regions, Genetic / immunology
-
Protein Serine-Threonine Kinases / antagonists & inhibitors
-
Protein-Tyrosine Kinases / antagonists & inhibitors
-
Tumor Necrosis Factor-alpha / physiology*
-
p38 Mitogen-Activated Protein Kinases
Substances
-
Tumor Necrosis Factor-alpha
-
Interferon-gamma
-
Nitric Oxide Synthase
-
Nitric Oxide Synthase Type II
-
Nos2 protein, mouse
-
Protein-Tyrosine Kinases
-
Protein Serine-Threonine Kinases
-
Calcium-Calmodulin-Dependent Protein Kinases
-
JNK Mitogen-Activated Protein Kinases
-
Mitogen-Activated Protein Kinase 1
-
Mitogen-Activated Protein Kinases
-
p38 Mitogen-Activated Protein Kinases
-
MAP Kinase Kinase Kinase 1
-
Map3k1 protein, mouse
-
MAP Kinase Kinase 4
-
Map2k4 protein, mouse
-
Mitogen-Activated Protein Kinase Kinases