A cytokine-selective defect in interleukin-1 beta-mediated acute phase gene expression in a subclone of the human hepatoma cell line (HEPG2)

J Biol Chem. 1989 May 5;264(13):7669-74.

Abstract

Several well-differentiated human hepatoma cell lines (HepG2, Hep3B) have been used to identify factors which regulate hepatic gene expression during the host response to inflammation/tissue injury (acute phase response). Studies in these cell lines, as well as in primary cultures of rat, rabbit, and mouse hepatocytes, have demonstrated that interleukin-1 beta (IL-1 beta), tumor necrosis factor (TNF-alpha), and interferon-beta 2 (IFN-beta 2) each mediate changes in expression of several hepatic acute phase genes. In this study we identify a subclone of the HepG2 cell line in which there is a selective defect in IL-1 beta-mediated acute phase gene expression. Recombinant human IL-1 beta mediates an increase in synthesis of the positive acute phase complement protein factor B and a decrease in synthesis of negative acute phase protein albumin in the parent uncloned HepG2 cell line (HG2Y), but not in the subclone HG2N. Recombinant human IFN-beta 2 and TNF-alpha, however, regulate acute phase protein synthesis in the subclone HG2N; i.e. IFN-beta 2 and TNF-alpha increase synthesis of factor B and decrease synthesis of albumin in both HG2Y and HG2N cells. Equilibrium binding analysis with 125I-rIL-1 beta at 4 degrees C showed that both HG2N and HG2Y cells bind IL-1 beta specifically and saturably. HG2N and HG2Y possess 3.8 and 4.0 x 10(3) plasma membrane receptors/cell with affinities of 0.96 and 1.07 x 10(-9) M, respectively. Thus, the defect in this subclone of the HepG2 cell line is likely to involve the signal transduction pathway for the biological activity of IL-1 beta and will be useful in elucidation of this signal transduction pathway.

Publication types

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

MeSH terms

  • Acute-Phase Proteins / genetics*
  • Albumins / genetics
  • Biological Factors / physiology*
  • Carcinoma, Hepatocellular / genetics*
  • Complement C4 / genetics
  • Complement Factor B / genetics
  • Cytokines
  • Gene Expression Regulation / drug effects
  • Humans
  • Interferon Type I / pharmacology
  • Interleukin-1 / physiology*
  • Liver Neoplasms
  • RNA, Messenger / genetics
  • Receptors, Immunologic / metabolism
  • Receptors, Interleukin-1
  • Tumor Cells, Cultured
  • Tumor Necrosis Factor-alpha / pharmacology

Substances

  • Acute-Phase Proteins
  • Albumins
  • Biological Factors
  • Complement C4
  • Cytokines
  • Interferon Type I
  • Interleukin-1
  • RNA, Messenger
  • Receptors, Immunologic
  • Receptors, Interleukin-1
  • Tumor Necrosis Factor-alpha
  • Complement Factor B