Morpholinos for splice modificatio

Morpholinos for splice modification


In vivo monitoring of cardiomyocyte proliferation to identify chemical modifiers of heart regeneration
Wen-Yee Choi, Matthew Gemberling, Jinhu Wang, Jennifer E. Holdway, Meng-Chieh Shen, Rolf O. Karlstrom, Kenneth D. Poss


Adult mammalian cardiomyocytes have little capacity to proliferate in response to injury, a deficiency that underlies the poor regenerative ability of human hearts after myocardial infarction. By contrast, zebrafish regenerate heart muscle after trauma by inducing proliferation of spared cardiomyocytes, providing a model for identifying manipulations that block or enhance these events. Although direct genetic or chemical screens of heart regeneration in adult zebrafish present several challenges, zebrafish embryos are ideal for high-throughput screening. Here, to visualize cardiomyocyte proliferation events in live zebrafish embryos, we generated transgenic zebrafish lines that employ fluorescent ubiquitylation-based cell cycle indicator (FUCCI) technology. We then performed a chemical screen and identified several small molecules that increase or reduce cardiomyocyte proliferation during heart development. These compounds act via Hedgehog, Insulin-like growth factor or Transforming growth factor β signaling pathways. Direct examination of heart regeneration after mechanical or genetic ablation injuries indicated that these pathways are activated in regenerating cardiomyocytes and that they can be pharmacologically manipulated to inhibit or enhance cardiomyocyte proliferation during adult heart regeneration. Our findings describe a new screening system that identifies molecules and pathways with the potential to modify heart regeneration.


  • Funding

    K.D.P. is an Early Career Scientist of the Howard Hughes Medical Institute. This work was supported by fellowships from the American Heart Association (AHA) [to W.-Y.C., M.G. and J.W.]; a fellowship from the National Institutes of Health (NIH) [F32 HL106987 to W.Y.C.]; grants from the NIH [NS039994 to R.O.K.; HL081674 to K.D.P.]; and grants from the American Federation for Aging Research and the AHA [to K.D.P.]. Deposited in PMC for release after 6 months.

  • Competing interests statement

    The authors declare no competing financial interests.

  • Supplementary material

    Supplementary material available online at

  • Accepted November 23, 2012.
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