Interleukin 1 beta down-regulates collagen and augments collagenase expression in human intestinal smooth muscle cells

Gastroenterology. 1996 Feb;110(2):344-50. doi: 10.1053/gast.1996.v110.pm8566579.


Background & aims: Smooth muscle cells resident in the intestinal wall play a significant role in the healing of the injured intestine and in the fibrosis that complicates Crohn's disease. The cytokine interleukin 1 beta (IL-1 beta) is involved in inflammatory bowel disease. The aim of this study was to determine the action of IL-1 beta on proliferation and collagen metabolism in human intestinal smooth muscle cells.

Results: IL-beta caused a three-fold increase in [3H]thymidine uptake at 100 pmol/L. This mitogenic effect was equipotent with that of platelet-derived growth factor when cells were exposed to IL-beta for 48 vs. 24 hours. IL-beta inhibited the secretion of procollagen into culture medium by 70% and the accumulation of newly synthesized procollagen in cells by 55%. In addition, IL-beta caused a concentration-dependent inhibition of steady-state levels of procollagen I and III messenger RNA (85% inhibition at 100 pmol/L) and a 3-5-fold augmentation of collagenase messenger RNA levels.

Conclusions: IL-beta is mitogenic for human intestinal smooth muscle cells, but this action is associated with a concomitant down-regulation of collagen synthesis and secretion and an augmention of collagenase expression.

Publication types

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

MeSH terms

  • Blotting, Northern
  • Cell Division
  • Collagen / metabolism*
  • Collagenases / genetics
  • Collagenases / metabolism*
  • Down-Regulation
  • Humans
  • Interleukin-1 / pharmacology
  • Interleukin-1 / physiology*
  • Intestinal Mucosa / metabolism
  • Intestines / cytology
  • Muscle, Smooth / cytology
  • Muscle, Smooth / metabolism*
  • Platelet-Derived Growth Factor / pharmacology
  • Procollagen / genetics
  • Procollagen / metabolism
  • RNA, Messenger / metabolism


  • Interleukin-1
  • Platelet-Derived Growth Factor
  • Procollagen
  • RNA, Messenger
  • Collagen
  • Collagenases