Vimentin is sufficient and required for wound repair and remodeling in alveolar epithelial cells

FASEB J. 2011 Nov;25(11):3873-83. doi: 10.1096/fj.10-170795. Epub 2011 Jul 29.

Abstract

The physiological and pathophysiological implications of the expression of vimentin, a type III intermediate filament protein, in alveolar epithelial cells (AECs) are unknown. We provide data demonstrating that vimentin is regulated by TGFβ1, a major cytokine released in response to acute lung injury and that vimentin is required for wound repair and remodeling of the alveolar epithelium. Quantitative real-time PCR shows a 16-fold induction of vimentin mRNA in TGFβ1-treated transformed AECs. Luciferase assays identify a Smad-binding element in the 5' promoter of vimentin responsible for TGFβ1-induced transcription. Notably, TGFβ1 induces vimentin protein expression in AECs, which is associated with a 2.5-fold increase in cell motility, resulting in increased rates of migration and wound closure. These effects are independent of cell proliferation. TGFβ1-mediated vimentin protein expression, cell migration, and wound closure are prevented by a pharmacological inhibitor of the Smad pathway and by expression of Ad-shRNA against vimentin. Conversely, overexpression of mEmerald-vimentin is sufficient for increased cell-migration and wound-closure rates. These results demonstrate that vimentin is required and sufficient for increased wound repair in an in vitro model of lung injury.

Publication types

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

MeSH terms

  • Animals
  • Cell Line
  • Cell Movement / drug effects
  • Cell Proliferation / drug effects
  • Humans
  • Male
  • Pulmonary Alveoli / cytology
  • Rats
  • Smad Proteins / physiology
  • Transforming Growth Factor beta1 / physiology
  • Vimentin / biosynthesis
  • Vimentin / physiology*
  • Wound Healing / physiology*

Substances

  • Smad Proteins
  • TGFB1 protein, human
  • Transforming Growth Factor beta1
  • Vimentin