Protein disulfide isomerase suppresses the transcriptional activity of NF-kappaB.
We report here that the transcriptional activity of NF-kappaB is negatively regulated by protein disulfide isomerase (PDI). Over-expression of PDI in RAW 264.7 cells strongly suppressed the LPS-induced production of inflammatory cytokines as well as NF-kappaB-dependent luciferase activity. This negative regulation of NF-kappaB was reversed by bacitracin, a PDI inhibitor. Interestingly, NF-kappaB/DNA complex formation and phosphorylation of NF-kappaB subunits was intact in PDI-expressing cells following stimulation with LPS. In addition, PDI and another redox regulator, thioredoxin (TRX), had opposite effects on NF-kappaB-dependent gene expression: activation of the NF-kappaB pathway by TRX was suppressed by expression of PDI in a dose-dependent manner. Finally, PDI expression was induced by the anti-inflammatory cytokine IL-10, and IL-10-mediated inhibition of LPS-induced IL-6 expression was reduced by bacitracin. These findings clearly demonstrate that PDI is a negative regulator of NF-kappaB, and may act downstream of IL-10 in this signaling pathway.
Higuchi
Toshio
T
Pharmaceutical Frontier Research Laboratories, Central Pharmaceutical Research Institute, Japan Tobacco Inc., Yokohama, Kanagawa, Japan. toshio.higuchi@ims.jti.co.jp
Watanabe
Yoshihiro
Y
Waga
Iwao
I
D000818:Animals; D001414:Bacitracin / Q000494:pharmacology; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D016753:Interleukin-10 / Q000378:metabolism; D015850:Interleukin-6 / Q000096:biosynthesis; D008070:Lipopolysaccharides / Q000037:antagonists & inhibitors / Q000494:pharmacology; D008264:Macrophages / Q000378:metabolism; D051379:Mice; D016328:NF-kappa B / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000235:genetics; D010766:Phosphorylation; D019704:Protein Disulfide-Isomerases / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D012333:RNA, Messenger / Q000096:biosynthesis; D013879:Thioredoxins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000494:pharmacology; D014158:Transcription, Genetic / Q000187:drug effects*; D015533:Transcriptional Activation / Q000187:drug effects; D014162:Transfection
D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; D015850:Interleukin-6; D008070:Lipopolysaccharides; D016328:NF-kappa B; D012333:RNA, Messenger; D016753:Interleukin-10; D001414:Bacitracin; D013879:Thioredoxins; D019704:Protein Disulfide-Isomerases