Inflammation location, but not type, determines the increase in TGF-beta1 and IGF-1 expression and collagen deposition in IBD intestine

Inflamm Bowel Dis. 2001 Feb;7(1):16-26. doi: 10.1097/00054725-200102000-00003.


Background and aims: Inflammatory bowel disease (IBD) is frequently complicated by extracellular matrix (ECM) changes that may result in fibrosis. Transforming growth factor (TGF)-beta1 and insulin-like growth factor (IGF)-1 mediate numerous ECM changes. Our aim was to determine whether TGF-beta1 and IGF-1 are involved in intestinal ECM collagen regulation and what impact the inflammatory infiltrate has on their expression.

Methods: TGF-beta1 and IGF-1 mRNA and protein were assessed in fibrosed Crohn's disease (CD), inflamed CD, inflamed ulcerative colitis (UC), and control intestine using in situ hybridization and immunohistochemistry. Collagen types I and III were quantified by electron immunohistochemistry.

Results: In CD, increased TGF-beta1 and IGF-1 mRNA expression was transmural. In UC, the increase was confined to the lamina propria and submucosa. In both, distribution of TGF-beta1 and IGF-1 protein matched mRNA expression and coincided with the distribution of the inflammatory infiltrate. An increase in the collagen type III:I ratio in both CD and UC also coincided with the inflammatory infiltrate.

Conclusions: These findings suggest that TGF-beta1 and IGF-1 are involved in intestinal ECM remodeling in IBD, and their enhanced expression depends on the presence and location of inflammatory infiltrates rather than the type of IBD.

MeSH terms

  • Collagen / biosynthesis
  • Collagen / metabolism*
  • Gene Expression Regulation
  • Humans
  • Immunohistochemistry
  • Inflammation / physiopathology*
  • Inflammatory Bowel Diseases / immunology*
  • Inflammatory Bowel Diseases / pathology
  • Insulin-Like Growth Factor I / biosynthesis*
  • Transforming Growth Factor beta / biosynthesis*
  • Transforming Growth Factor beta1


  • TGFB1 protein, human
  • Transforming Growth Factor beta
  • Transforming Growth Factor beta1
  • Insulin-Like Growth Factor I
  • Collagen