DNase I-hypersensitive sites enhance alpha1(I) collagen gene expression in hepatic stellate cells

Hepatology. 2003 Feb;37(2):267-76. doi: 10.1053/jhep.2003.50067.


Liver fibrosis is characterized by a dramatic increase in the expression of type I collagen. Several deoxyribonuclease (DNase) I-hypersensitive sites (HS) have been located in the distal 5'-flanking region of the alpha1(I) collagen gene that are specific to collagen-producing cells. To assess the role of the DNase I-HS in regulating alpha1(I) collagen gene expression in hepatic stellate cells (HSCs), 3 transgenic mouse lines expressing collagen-alpha1(I) reporter genes were used (Krempen et al. Gene Expr 1999;8:151-163). The pCol9GFP transgene contains the collagen gene promoter (-3122 to +111) linked to the green fluorescent protein (GFP) reporter gene. The pCol9GFP-HS4,5 transgene contains HS4,5 and pColGFP-HS8,9 contains HS8,9 positioned upstream of the collagen promoter in pCol9GFP. HSCs isolated from transgenic mice containing pCol9GFPHS4,5 and pColGFP-HS8,9 showed earlier and higher GFP expression patterns than HSCs isolated from pCol9GFP mice. HSCs from pCol9GFP-HS4,5 showed the highest levels of GFP expression and culture-induced expression correlated with induction of the endogenous alpha1(I) collagen gene. After CCl(4) administration, pCol9GFP-HS4,5 mice showed increased GFP expression compared with pCol9GFP mice in both whole liver extracts and isolated HSCs. Several sites for DNA-protein interactions in both HS4 and HS5 were identified that included a binding site for activator protein 1. In conclusion, DNase I-HS4,5 enhance expression of the alpha1(I) collagen gene promoter in HSCs both in vitro and in vivo after a fibrogenic stimulus. The collagen-GFP transgenic mice provide a convenient and reliable model system to investigate the molecular mechanisms controlling increased collagen expression during fibrosis.

Publication types

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

MeSH terms

  • Animals
  • Base Sequence / genetics
  • Binding Sites / genetics
  • Carbon Tetrachloride
  • Cells, Cultured
  • Collagen Type I / genetics*
  • DNA / metabolism
  • Deoxyribonuclease I / physiology*
  • Gene Expression / physiology*
  • Gene Expression Regulation, Enzymologic*
  • Hepatocytes / physiology*
  • Liver / cytology
  • Liver / metabolism*
  • Liver Cirrhosis / chemically induced
  • Liver Cirrhosis / genetics
  • Mice
  • Mice, Inbred C3H
  • Mice, Inbred C57BL
  • Mice, Transgenic / genetics
  • Molecular Sequence Data
  • Promoter Regions, Genetic
  • Proteins / metabolism
  • Transgenes / physiology


  • Collagen Type I
  • Proteins
  • DNA
  • Carbon Tetrachloride
  • Deoxyribonuclease I