N-acetylcysteine suppresses TNF-induced NF-kappaB activation through inhibition of IkappaB kinases.
Here, we used a reductant, N-acetyl-L-cysteine (NAC), to investigate the redox-sensitive step(s) in the signalling pathway from the tumor necrosis factor (TNF) receptor to nuclear factor kappaB (NF-kappaB). We found that NAC suppressed NF-kappaB activation triggered by TNF or by overexpression of either the TNF receptor-associated death domain protein, TNF receptor-associated factor 2, NF-kappaB-inducing kinase (NIK), or IkappaB kinases (IKKalpha and IKKbeta). NAC also suppressed the TNF-induced activation of IKKalpha and IKKbeta, phosphorylation and degradation of IkappaB, and nuclear translocation of NF-kappaB. Furthermore, NAC suppressed the activation of IKKalpha and IKKbeta triggered by the overexpression of NIK. These results indicate that IKKalpha and IKKbeta are subject to redox regulation in the cells, and that NAC inhibits NF-kappaB activation through the suppression of these kinases.
Oka
S
S
Department of Life Science, Faculty of Science, Himeji Institute of Technology, Kamigori-chou, Akoh-gun, Hyogo, Japan.
Kamata
H
H
Kamata
K
K
Yagisawa
H
H
Hirata
H
H
D000111:Acetylcysteine / Q000378:metabolism* / Q000494:pharmacology; D001692:Biological Transport; D002467:Cell Nucleus / Q000378:metabolism; D004229:Dithiothreitol / Q000494:pharmacology; D016166:Free Radical Scavengers / Q000378:metabolism* / Q000494:pharmacology; D006367:HeLa Cells; D006801:Humans; D051550:I-kappa B Kinase; D016328:NF-kappa B / Q000378:metabolism*; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D011506:Proteins / Q000378:metabolism; D018124:Receptors, Tumor Necrosis Factor / Q000378:metabolism; D047990:TNF Receptor-Associated Factor 1; D047992:TNF Receptor-Associated Factor 2; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism* / Q000494:pharmacology; D000097782:NF-kappaB-Inducing Kinase
D000111:Acetylcysteine; D004229:Dithiothreitol; D016166:Free Radical Scavengers; D051550:I-kappa B Kinase; D016328:NF-kappa B; D017346:Protein Serine-Threonine Kinases; D011506:Proteins; D018124:Receptors, Tumor Necrosis Factor; D047990:TNF Receptor-Associated Factor 1; D047992:TNF Receptor-Associated Factor 2; D014409:Tumor Necrosis Factor-alpha; D000097782:NF-kappaB-Inducing Kinase; C496559:CHUK protein, human; C496560:IKBKB protein, human; C496565:IKBKE protein, human