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

Abstract

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.

• Authors: David Lagares, Rosa Ana García-Fernández, Clara López Jiménez, Noemi Magán-Marchal, Oscar Busnadiego, Santiago Lamas, Fernando Rodríguez-Pascual
• Journal: Arthritis and rheumatism (Arthritis Rheum) Vol. 62 Issue 3 Pg. 878-89 (Mar 2010) ISSN: 1529-0131 [Electronic] United States
• PMID: 20131241 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• 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

Topics

• 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, pathology)
• Sulfonamides (pharmacology)
• Transfection
• Transforming Growth Factor beta1 (physiology)
• Wound Healing (physiology)