High-efficiency reprogramming of fibroblasts into cardiomyocytes requires suppression of pro-fibrotic signalling

Nat Commun. 2015 Sep 10:6:8243. doi: 10.1038/ncomms9243.


Direct reprogramming of fibroblasts into cardiomyocytes by forced expression of cardiomyogenic factors, GMT (GATA4, Mef2C, Tbx5) or GHMT (GATA4, Hand2, Mef2C, Tbx5), has recently been demonstrated, suggesting a novel therapeutic strategy for cardiac repair. However, current approaches are inefficient. Here we demonstrate that pro-fibrotic signalling potently antagonizes cardiac reprogramming. Remarkably, inhibition of pro-fibrotic signalling using small molecules that target the transforming growth factor-β or Rho-associated kinase pathways converts embryonic fibroblasts into functional cardiomyocyte-like cells, with the efficiency up to 60%. Conversely, overactivation of these pro-fibrotic signalling networks attenuates cardiac reprogramming. Furthermore, inhibition of pro-fibrotic signalling dramatically enhances the kinetics of cardiac reprogramming, with spontaneously contracting cardiomyocytes emerging in less than 2 weeks, as opposed to 4 weeks with GHMT alone. These findings provide new insights into the molecular mechanisms underlying cardiac conversion of fibroblasts and would enhance efforts to generate cardiomyocytes for clinical applications.

Publication types

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

MeSH terms

  • Action Potentials
  • Animals
  • Basic Helix-Loop-Helix Transcription Factors / genetics
  • Blotting, Western
  • Cellular Reprogramming / genetics*
  • Cellular Reprogramming Techniques / methods*
  • Chromatin Immunoprecipitation
  • Embryo, Mammalian
  • Fibroblasts / cytology
  • Fibroblasts / metabolism*
  • Fibrosis
  • GATA4 Transcription Factor / genetics
  • Immunohistochemistry
  • MEF2 Transcription Factors / genetics
  • Mice
  • MicroRNAs / genetics
  • Myocytes, Cardiac / cytology
  • Myocytes, Cardiac / metabolism*
  • Real-Time Polymerase Chain Reaction
  • Sequence Analysis, RNA
  • Signal Transduction
  • T-Box Domain Proteins / genetics
  • Transforming Growth Factor beta / antagonists & inhibitors*
  • rho-Associated Kinases / antagonists & inhibitors*


  • Basic Helix-Loop-Helix Transcription Factors
  • GATA4 Transcription Factor
  • Gata4 protein, mouse
  • Hand2 protein, mouse
  • MEF2 Transcription Factors
  • Mef2c protein, mouse
  • MicroRNAs
  • Mirn1 microRNA, mouse
  • Mirn133 microRNA, mouse
  • T-Box Domain Proteins
  • T-box transcription factor 5
  • Transforming Growth Factor beta
  • rho-Associated Kinases