N-acetylcysteine attenuates TNF-alpha-induced p38 MAP kinase activation and p38 MAP kinase-mediated IL-8 production by human pulmonary vascular endothelial cells.
1. We have previously shown that tumour necrosis factor-alpha (TNF-alpha) activates p38 mitogen-activated protein (MAP) kinase to produce interleukin-8 (IL-8) by human pulmonary vascular endothelial cells. Reactive oxygen species (ROS) including H(2)O(2) generated by TNF-alpha can act as signalling intermediates for cytokine induction; therefore, scavenging ROS by anti-oxidants is important for the regulation of cytokine production. However, the effect of N-acetylcysteine (NAC), which acts as a precursor of glutathione (GSH) synthesis, on TNF-alpha-induced activation of p38 MAP kinase pathway and p38 MAP kinase-mediated IL-8 production by human pulmonary vascular endothelial cells has not been determined. To clarify these issues, we examined the effect of NAC on TNF-alpha-induced activation of p38 MAP kinase, MAP kinase kinase (MKK) 3 and MKK6 which are upstream regulators of p38 MAP kinase, and p38 MAP kinase-mediated IL-8 production. 2. Human pulmonary vascular endothelial cells that had been preincubated with NAC were stimulated with TNF-alpha and then the activation of p38 MAP kinase and MKK3/MKK6 in the cells and IL-8 concentrations in the culture supernatants were determined. 3. Intracellular GSH levels increased in NAC-treated cells. 4. NAC attenuated TNF-alpha-induced activation of p38 MAP kinase and MKK3/MKK6. 5. NAC attenuated p38 MAP kinase-mediated IL-8 production by TNF-alpha-stimulated cells. 6. These results indicate that the cellular reduction and oxidation (redox) regulated by intracellular GSH is critical for TNF-alpha-induced activation of p38 MAP kinase pathway and p38 MAP kinase-mediated IL-8 production by human pulmonary vascular endothelial cells, and we emphasize that anti-oxidant therapy is an important strategy for the treatment of acute lung injury.
Hashimoto
S
S
First Department of Internal Medicine, Nihon University School of Medicine, Tokyo 173-8610, Japan. shuh@med.nihon-u.ac.jp
Gon
Y
Y
Matsumoto
K
K
Takeshita
I
I
Horie
T
T
D000111:Acetylcysteine / Q000494:pharmacology*; D015153:Blotting, Western; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D004789:Enzyme Activation; D005978:Glutathione / Q000378:metabolism; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D016209:Interleukin-8 / Q000096:biosynthesis*; D048371:MAP Kinase Kinase 3; D048669:MAP Kinase Kinase 6; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D011651:Pulmonary Artery / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D048051:p38 Mitogen-Activated Protein Kinases
D016209:Interleukin-8; D014409:Tumor Necrosis Factor-alpha; D006861:Hydrogen Peroxide; D011505:Protein-Tyrosine Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D048371:MAP Kinase Kinase 3; D048669:MAP Kinase Kinase 6; C482530:MAP2K3 protein, human; C482566:MAP2K6 protein, human; D020929:Mitogen-Activated Protein Kinase Kinases; D005978:Glutathione; D000111:Acetylcysteine