Targeting the myofibroblast genetic switch: inhibitors of myocardin-related transcription factor/serum response factor-regulated gene transcription prevent fibrosis in a murine model of skin injury

J Pharmacol Exp Ther. 2014 Jun;349(3):480-6. doi: 10.1124/jpet.114.213520. Epub 2014 Apr 4.

Abstract

Systemic sclerosis (SSc), or scleroderma, similar to many fibrotic disorders, lacks effective therapies. Current trials focus on anti-inflammatory drugs or targeted approaches aimed at one of the many receptor mechanisms initiating fibrosis. In light of evidence that a myocardin-related transcription factor (MRTF)-and serum response factor (SRF)-regulated gene transcriptional program induced by Rho GTPases is essential for myofibroblast activation, we explored the hypothesis that inhibitors of this pathway may represent novel antifibrotics. MRTF/SRF-regulated genes show spontaneously increased expression in primary dermal fibroblasts from patients with diffuse cutaneous SSc. A novel small-molecule inhibitor of MRTF/SRF-regulated transcription (CCG-203971) inhibits expression of connective tissue growth factor (CTGF), α-smooth muscle actin (α-SMA), and collagen 1 (COL1A2) in both SSc fibroblasts and in lysophosphatidic acid (LPA)-and transforming growth factor β (TGFβ)-stimulated fibroblasts. In vivo treatment with CCG-203971 also prevented bleomycin-induced skin thickening and collagen deposition. Thus, targeting the MRTF/SRF gene transcription pathway could provide an efficacious new approach to therapy for SSc and other fibrotic disorders.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Culture Techniques
  • Cell Proliferation / drug effects
  • Collagen Type I / genetics
  • Connective Tissue Growth Factor / genetics
  • DNA-Binding Proteins / genetics*
  • Disease Models, Animal
  • Female
  • Humans
  • Lysophospholipids / pharmacology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Middle Aged
  • Myofibroblasts / drug effects*
  • Myofibroblasts / metabolism
  • Myofibroblasts / pathology
  • NIH 3T3 Cells
  • Nipecotic Acids / administration & dosage
  • Nipecotic Acids / pharmacology
  • Nipecotic Acids / therapeutic use*
  • Oncogene Proteins, Fusion / genetics*
  • Scleroderma, Systemic / drug therapy*
  • Scleroderma, Systemic / genetics
  • Scleroderma, Systemic / pathology
  • Serum Response Factor / genetics*
  • Trans-Activators
  • Transcription, Genetic / drug effects*
  • Transforming Growth Factor beta / pharmacology

Substances

  • CCN2 protein, human
  • Collagen Type I
  • DNA-Binding Proteins
  • Lysophospholipids
  • MRTFA protein, human
  • N-(4-chlorophenyl)-1-((3-(furan-2-yl)phenyl)carbonyl)piperidine-3-carboxamide
  • Nipecotic Acids
  • Oncogene Proteins, Fusion
  • Serum Response Factor
  • Trans-Activators
  • Transforming Growth Factor beta
  • Connective Tissue Growth Factor
  • lysophosphatidic acid