Reversible and irreversible differentiation of cardiac fibroblasts

Cardiovasc Res. 2014 Mar 1;101(3):411-22. doi: 10.1093/cvr/cvt338. Epub 2013 Dec 23.


Aims: Differentiation of cardiac fibroblasts (Fbs) into myofibroblasts (MyoFbs) is responsible for connective tissue build-up in myocardial remodelling. We examined MyoFb differentiation and reversibility.

Methods and results: Adult rat cardiac Fbs were cultured on a plastic substratum providing mechanical stress, with conditions to obtain different levels of Fb differentiation. Fb spontaneously differentiated to proliferating MyoFb (p-MyoFb) with stress fibre formation decorated with alpha-smooth muscle actin (α-SMA). Transforming growth factor-β1 (TGF-β1) promoted differentiation into α-SMA-positive MyoFb showing near the absence of proliferation, i.e. non-p-MyoFb. SD-208, a TGF-β-receptor-I (TGF-β-RI) kinase blocker, inhibited p-MyoFb differentiation as shown by stress fibre absence, low α-SMA expression, and high proliferation levels. Fb seeded in collagen matrices induced no contraction, whereas p-MyoFb and non-p-MyoFb induced 2.5- and four-fold contraction. Fb produced little collagen but high levels of interleukin-10. Non-p-MyoFb had high collagen production and high monocyte chemoattractant protein-1 and tissue inhibitor of metalloproteinases-1 levels. Transcriptome analysis indicated differential activation of gene networks related to differentiation of MyoFb (e.g. paxilin and PAK) and reduced proliferation of non-p-MyoFb (e.g. cyclins and cell cycle regulation). Dedifferentiation of p-MyoFb with stress fibre de-polymerization, but not of non-p-MyoFb, was induced by SD-208 despite maintained stress. Stress fibre de-polymerization could also be induced by mechanical strain release in p-MyoFb and non-p-MyoFb (2-day cultures in unrestrained 3-D collagen matrices). Only p-MyoFb showed true dedifferentiation after long-term 3-D cultures.

Conclusions: Fb, p-MyoFb, and non-p-MyoFb have a distinct gene expression, ultrastructural, and functional profile. Both reduction in mechanical strain and TGF-β-RI kinase inhibition can reverse p-MyoFb differentiation but not non-p-MyoFb.

Keywords: Cardiac fibroblast; Dedifferentiation; Myofibroblast.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Differentiation / drug effects
  • Cell Differentiation / radiation effects
  • Cells, Cultured
  • Collagen / metabolism
  • Gene Expression / drug effects
  • Male
  • Myofibroblasts / cytology
  • Myofibroblasts / metabolism*
  • Pteridines / pharmacology
  • Rats
  • Rats, Wistar
  • Receptors, Transforming Growth Factor beta / metabolism
  • Stress, Physiological
  • Transforming Growth Factor beta1 / metabolism


  • Pteridines
  • Receptors, Transforming Growth Factor beta
  • SD-208
  • Transforming Growth Factor beta1
  • Collagen