Inhibition of focal adhesion kinase prevents experimental lung fibrosis and myofibroblast formation

Arthritis Rheum. 2012 May;64(5):1653-64. doi: 10.1002/art.33482.


Objective: Enhanced adhesive signaling, including activation of focal adhesion kinase (FAK), is a hallmark of fibroblasts from lung fibrosis patients, and FAK has therefore been hypothesized to be a key mediator of this disease. This study was undertaken to characterize the contribution of FAK to the development of pulmonary fibrosis both in vivo and in vitro.

Methods: FAK expression and activity were analyzed in lung tissue samples from lung fibrosis patients by immunohistochemistry. Mice orally treated with the FAK inhibitor PF-562,271, or with small interfering RNA (siRNA)-mediated silencing of FAK were exposed to intratracheally instilled bleomycin to induce lung fibrosis, and lungs were harvested for histologic and biochemical analysis. Using endothelin 1 (ET-1) as a stimulus, cell adhesion and contraction, as well as profibrotic gene expression, were studied in fibroblasts isolated from wild-type and FAK-deficient mouse embryos. ET-1-mediated FAK activation and gene expression were studied in primary mouse lung fibroblasts, as well as in wild-type and β1 integrin-deficient mouse fibroblasts.

Results: FAK expression and activity were up-regulated in fibroblast foci and remodeled vessels from lung fibrosis patients. Pharmacologic or siRNA-mediated targeting of FAK resulted in marked abrogation of bleomycin-induced lung fibrosis in mice. Loss of FAK impaired the acquisition of a profibrotic phenotype in response to ET-1. Profibrotic gene expression leading to myofibroblast differentiation required cell adhesion, and was driven by JNK activation through β1 integrin/FAK signaling.

Conclusion: These results implicate FAK as a central mediator of fibrogenesis, and highlight this kinase as a potential therapeutic target in fibrotic diseases.

Publication types

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

MeSH terms

  • Animals
  • Cell Adhesion / drug effects
  • Cells, Cultured
  • Disease Models, Animal
  • Endothelin-1 / pharmacology
  • Enzyme Inhibitors / pharmacology*
  • Female
  • Focal Adhesion Protein-Tyrosine Kinases / antagonists & inhibitors*
  • Focal Adhesion Protein-Tyrosine Kinases / genetics
  • Focal Adhesion Protein-Tyrosine Kinases / metabolism
  • Gene Silencing
  • Humans
  • Indoles / pharmacology*
  • Lung / drug effects*
  • Lung / enzymology
  • Lung / pathology
  • Male
  • Mice
  • Middle Aged
  • Myofibroblasts / drug effects*
  • Myofibroblasts / metabolism
  • Myofibroblasts / pathology
  • Pulmonary Fibrosis / enzymology
  • Pulmonary Fibrosis / pathology
  • Pulmonary Fibrosis / prevention & control*
  • RNA, Small Interfering / genetics
  • Sulfonamides / pharmacology*
  • Up-Regulation / drug effects


  • Endothelin-1
  • Enzyme Inhibitors
  • Indoles
  • N-methyl-N-(3-((2-(2-oxo-2,3-dihydro-1H-indol-5-ylamino)-5-trifluoromethyl-pyrimidin-4-ylamino)-methyl)-pyridin-2-yl)-methanesulfonamide
  • RNA, Small Interfering
  • Sulfonamides
  • Focal Adhesion Protein-Tyrosine Kinases