Ensuring expression of four core cardiogenic transcription factors enhances cardiac reprogramming

Sci Rep. 2019 Apr 24;9(1):6362. doi: 10.1038/s41598-019-42945-w.


Previous studies have shown that forced expression of core cardiogenic transcription factors can directly reprogram fibroblasts to induced cardiomyocyte-like cells (iCMs). This cardiac reprogramming approach suggests a potential strategy for cardiomyocyte regeneration. However, a major challenge of this approach remains the low conversion rate. Here, we showed that ensuring expression of four cardiogenic transcription factors (i.e. Gata4 (G), Hand2 (H), Mef2c (M), and Tbx5 (T)) in individual fibroblasts is an initial bottleneck for cardiac reprogramming. Following co-transduction of three or four retroviral vectors encoding individual cardiogenic transcription factors, only a minor subpopulation of cells indeed expressed all three (GMT) or four (GHMT) factors. By selectively analyzing subpopulations of cells expressing various combinations of reprogramming factors, we found that co-expression of GMT in individual fibroblasts is sufficient to induce sarcomeric proteins. However, only a small fraction of those cells expressing GMT were able to develop organized sarcomeric structures and contractility. In contrast, ensuring expression of GHMT markedly enhanced the development of contractile cardiac structures and functions in fibroblasts, although its incremental effect on sarcomeric protein induction was relatively small. Our findings provide new insights into the mechanistic basis of inefficient cardiac reprogramming and can help to devise efficient reprogramming strategies.

Publication types

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

MeSH terms

  • Animals
  • Basic Helix-Loop-Helix Transcription Factors / genetics
  • Basic Helix-Loop-Helix Transcription Factors / metabolism
  • Cell Differentiation
  • Cells, Cultured
  • Cellular Reprogramming*
  • Fibroblasts / cytology
  • Fibroblasts / metabolism*
  • GATA4 Transcription Factor / genetics
  • GATA4 Transcription Factor / metabolism
  • Gene Expression
  • MEF2 Transcription Factors / genetics
  • MEF2 Transcription Factors / metabolism
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Muscle Proteins / genetics
  • Muscle Proteins / metabolism
  • Myocytes, Cardiac / cytology
  • Myocytes, Cardiac / metabolism*
  • Sarcomeres / metabolism
  • T-Box Domain Proteins / genetics
  • T-Box Domain Proteins / metabolism
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*


  • Basic Helix-Loop-Helix Transcription Factors
  • GATA4 Transcription Factor
  • Hand2 protein, mouse
  • MEF2 Transcription Factors
  • Muscle Proteins
  • T-Box Domain Proteins
  • T-box transcription factor 5
  • Transcription Factors