Endothelin 1 contributes to the effect of transforming growth factor beta1 on wound repair and skin fibrosis

Arthritis Rheum. 2010 Mar;62(3):878-89. doi: 10.1002/art.27307.


Objective: To characterize the pathways induced by transforming growth factor beta1 (TGFbeta1) that lead to the expression of endothelin 1 (ET-1) in human dermal fibroblasts, and to study the effects of TGFbeta1 and ET-1 on the acquisition of a profibrotic phenotype and assess the contribution of the TGFbeta1/ET-1 axis to skin wound healing and fibrosis in vivo.

Methods: The mechanism of induction of ET-1 expression by TGFbeta1 and its effect on the expression of alpha-smooth muscle actin and type I collagen were studied in human dermal fibroblasts, in experiments involving the TGFbeta receptor inhibitor GW788388 and the ET receptor antagonist bosentan, by real-time reverse transcription-polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay, immunofluorescence, Western blotting, and promoter/reporter transient transfection analyses. Experiments assessing dermal wound healing in mice were performed with adenovirus-driven overexpression of active TGFbeta1 and ET-1, with or without treatment with bosentan. The contributions of TGFbeta1 and ET-1 to the fibrotic response were also assessed in a mouse model of bleomycin-induced skin fibrosis, by histologic, immunohistochemical, RT-PCR, and protein analyses.

Results: TGFbeta1 induced ET-1 expression in human dermal fibroblasts through Smad- and activator protein 1/JNK-dependent signaling. The ability of TGFbeta1 to induce the expression of profibrotic genes was dependent on ET-1. Adenovirus-mediated overexpression of TGFbeta1 and ET-1 in mouse skin was associated with accelerated wound closure, increased fibrogenesis, and excessive scarring. Treatment with bosentan prevented the effects of TGFbeta1. In the bleomycin-induced fibrosis model, treatment with GW788388 and bosentan prevented the fibrotic response.

Conclusion: Our results strongly support the notion that the TGFbeta1/ET-1 axis has a role in wound repair and skin fibrosis. ET-1 receptor antagonists, such as bosentan, may represent a useful therapeutic tool in the treatment of excessive scarring and fibrosis-related diseases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / analysis
  • Animals
  • Benzamides / pharmacology
  • Bleomycin
  • Blotting, Western
  • Bosentan
  • Cells, Cultured
  • Collagen Type I / analysis
  • Endothelin-1 / physiology*
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Fibroblasts / physiology
  • Fibrosis / physiopathology
  • Mice
  • Mice, Inbred C3H
  • Pyrazoles / pharmacology
  • RNA, Messenger / analysis
  • Reverse Transcriptase Polymerase Chain Reaction
  • Skin / drug effects
  • Skin / pathology*
  • Sulfonamides / pharmacology
  • Transfection
  • Transforming Growth Factor beta1 / physiology*
  • Wound Healing / physiology*


  • 4-(4-(3-(pyridin-2-yl)-1H-pyrazol-4-yl)pyridin-2-yl)-N-(tetrahydro-2H-pyran-4-yl)benzamide
  • Actins
  • Benzamides
  • Collagen Type I
  • Endothelin-1
  • Pyrazoles
  • RNA, Messenger
  • Sulfonamides
  • Transforming Growth Factor beta1
  • Bleomycin
  • Bosentan