Relaxin alone and in conjunction with interferon-gamma decreases collagen synthesis by cultured human scleroderma fibroblasts

J Invest Dermatol. 1992 Sep;99(3):337-42. doi: 10.1111/1523-1747.ep12616665.


Fibroblasts derived from the involved skin of scleroderma patients frequently display a phenotype of supernormal collagen expression when cultured. Fibroblasts displaying this phenotype derived from seven patients were treated with relaxin (1-100 ng/ml) and interferon-gamma (1-100 U/ml), individually and in combination, to assess the relative abilities of these cytokines to down-modulate collagen synthesis and secretion. Scleroderma fibroblasts displayed varying sensitivities to both relaxin and interferon-gamma. Relaxin (100 ng/ml) decreased expression of collagen by six of seven lines tested from 8 to 59% compared to untreated cultures. Interferon-gamma (100 U/ml) depressed collagen secretion by all seven lines in a range from 7 to 89%. When relaxin and interferon-gamma were used in combination, relaxin augmented IFN-gamma-induced decreases in collagen secretion in four of seven lines. In three of these lines, the use of relaxin in conjunction with suboptimal doses of interferon-gamma resulted in decreases equivalent to or greater than that seen with a tenfold higher concentration of interferon-gamma. This study demonstrates the ability of relaxin to directly alter the excessive collagen-producing phenotype of scleroderma fibroblasts. In addition, in some cases, combining relaxin and interferon-gamma resulted in a cooperative effect in decreasing collagen expression by scleroderma cells in vitro.

Publication types

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

MeSH terms

  • Cells, Cultured
  • Collagen / biosynthesis*
  • Fibroblasts / metabolism
  • Humans
  • Interferon-gamma / pharmacology*
  • Relaxin / pharmacology*
  • Scleroderma, Systemic / metabolism*


  • Interferon-gamma
  • Relaxin
  • Collagen