NF-kappaB inhibits expression of the alpha1(I) collagen gene

DNA Cell Biol. 1999 Oct;18(10):751-61. doi: 10.1089/104454999314890.


Fibrosis results from an increase in the synthesis and deposition of type I collagen. Fibrosis is frequently associated with inflammation, which is accompanied by increased levels of tumor necrosis factor-alpha (TNFalpha) and activation of the transcription factor NF-kappaB. However, several agents known to activate NF-kappaB, such as phorbol 12-myristate 13-acetate (PMA) and TNFalpha, result in decreased expression of type I collagen. Therefore, we directly examined the effects of NF-kappaB on alpha1(I) collagen gene expression in two collagen-producing cells, NIH 3T3 fibroblasts and hepatic stellate cells (HSCs). Transient transfections of NIH 3T3 cells or HSCs using NF-kappaB p50, p65, and c-Rel expression plasmids with collagen reporter gene plasmids demonstrated a strong inhibitory effect on transcription of the collagen gene promoter. Dose-response curves showed that p65 was a stronger inhibitor of collagen gene expression than was NF-kappaB p50 or c-Rel (maximum inhibition 90%). Transient transfections with reporter gene plasmids containing one or two Spl binding sites demonstrated similar inhibitory effects of NF-kappaB p65 on the activity of these reporter genes, suggesting that the inhibitory effects of NF-kappaB p65 are mediated through the critical Spl binding sites in the alpha1(I) collagen gene promoter. Cotransfection experiments using either a super-repressor I[ke]B or Spl partially blocked the inhibitory effects of p65 on collagen reporter gene activity. Coimmunoprecipitation experiments demonstrated that NF-kappaB and Spl do interact in vivo. Nuclear run-on assays showed that NF-kappaB p65 inhibited transcription of the endogenous alpha1(I) collagen gene. Together, these results demonstrate that NF-kappaB decreases transcription of the alpha1(I) collagen gene.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • 3T3 Cells
  • Animals
  • Binding Sites
  • Collagen / biosynthesis
  • Collagen / genetics*
  • Consensus Sequence
  • Fibrosis
  • Gene Expression Regulation*
  • Genes, Reporter
  • Genetic Vectors / genetics
  • Humans
  • I-kappa B Proteins / physiology
  • Liver / cytology
  • Liver Cirrhosis / genetics
  • Macromolecular Substances
  • Male
  • Mice
  • NF-kappa B / genetics
  • NF-kappa B / physiology*
  • NF-kappa B p50 Subunit
  • Promoter Regions, Genetic / genetics
  • Protein Binding
  • Protein Isoforms / biosynthesis
  • Protein Isoforms / genetics*
  • Protein Isoforms / physiology
  • Proto-Oncogene Proteins c-rel / genetics
  • Proto-Oncogene Proteins c-rel / physiology*
  • RNA, Messenger / biosynthesis
  • Rats
  • Rats, Sprague-Dawley
  • Sp1 Transcription Factor / metabolism
  • Transcription Factor RelA
  • Transfection


  • I-kappa B Proteins
  • Macromolecular Substances
  • NF-kappa B
  • NF-kappa B p50 Subunit
  • Protein Isoforms
  • Proto-Oncogene Proteins c-rel
  • RNA, Messenger
  • Sp1 Transcription Factor
  • Transcription Factor RelA
  • Collagen