Dual function of interleukin-1beta for the regulation of interleukin-6-induced suppressor of cytokine signaling 3 expression

J Biol Chem. 2004 Oct 22;279(43):45279-89. doi: 10.1074/jbc.M313072200. Epub 2004 Aug 11.

Abstract

Interleukin-6 (IL-6) exerts pro- as well as anti-inflammatory activities in response to infection, injury, or other stimuli that affect the homeostasis of the organism. IL-6-induced expression of acute-phase protein genes in the liver is tightly regulated through both IL-6-induced feedback inhibitors and the activity of pro-inflammatory cytokines such as tumor necrosis factor alpha and interleukin-1beta. In previous studies mechanisms for how IL-1beta counteracts IL-6-dependent acute-phase protein gene induction have been proposed. Herein we analyzed IL-1beta-mediated regulation of IL-6-induced expression of the feedback inhibitor SOCS3. In hepatocytes IL-1beta alone does not induce SOCS3 expression, but it counteracts SOCS3-promoter activation in long term studies. Surprisingly, short term stimulation revealed IL-1beta to be a potent enhancer of SOCS3 expression in concert with IL-6. This activity of IL-1beta does not depend on IL-1beta-dependent STAT1-serine phosphorylation but on NF-kappaB-dependent gene induction. Such a regulatory network allows IL-1beta to counteract IL-6-dependent expression of acute-phase protein genes without inhibiting IL-6-induced SOCS3 expression and provides a reasonable mechanism for the IL-1beta-dependent inhibition of acute-phase gene induction, because reduced SOCS3 expression would lead to enhanced IL-6 activity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blotting, Northern
  • Cell Line
  • Cell Nucleus / metabolism
  • Chromatin / metabolism
  • Cytokines / metabolism
  • DNA-Binding Proteins / metabolism
  • Gene Expression Regulation
  • Gene Transfer Techniques
  • Genes, Reporter
  • Genetic Vectors
  • Humans
  • Immunoblotting
  • Immunoprecipitation
  • Interleukin-1 / metabolism
  • Interleukin-1 / physiology*
  • Interleukin-6 / metabolism*
  • NF-kappa B / metabolism
  • Phosphorylation
  • Promoter Regions, Genetic
  • RNA, Messenger / metabolism
  • RNA, Small Interfering / metabolism
  • Repressor Proteins / metabolism*
  • Retroviridae / genetics
  • STAT1 Transcription Factor
  • Serine / chemistry
  • Suppressor of Cytokine Signaling 3 Protein
  • Suppressor of Cytokine Signaling Proteins
  • Time Factors
  • Trans-Activators / metabolism
  • Transcription Factors / metabolism*
  • Transcriptional Activation
  • Transfection

Substances

  • Chromatin
  • Cytokines
  • DNA-Binding Proteins
  • Interleukin-1
  • Interleukin-6
  • NF-kappa B
  • RNA, Messenger
  • RNA, Small Interfering
  • Repressor Proteins
  • SOCS3 protein, human
  • STAT1 Transcription Factor
  • STAT1 protein, human
  • Suppressor of Cytokine Signaling 3 Protein
  • Suppressor of Cytokine Signaling Proteins
  • Trans-Activators
  • Transcription Factors
  • Serine