title: In vivo monitoring of cardiomyocyte proliferation to identify chemical modifiers of heart regeneration.
abstract: 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.
authors.affiliation: Department of Cell Biology and Howard Hughes Medical Institute, Duke University Medical Center, Durham, NC 27710,  USA.
authors.forename: Wen-Yee
authors.initials: WY
authors.lastname: Choi
authors.forename: Matthew
authors.initials: M
authors.lastname: Gemberling
authors.forename: Jinhu
authors.initials: J
authors.lastname: Wang
authors.forename: Jennifer E
authors.initials: JE
authors.lastname: Holdway
authors.forename: Meng-Chieh
authors.initials: MC
authors.lastname: Shen
authors.forename: Rolf O
authors.initials: RO
authors.lastname: Karlstrom
authors.forename: Kenneth D
authors.initials: KD
authors.lastname: Poss
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified / Q000196:embryology / Q000378:metabolism / Q000502:physiology; D015415:Biomarkers / Q000378:metabolism; D002396:Catechols / Q000494:pharmacology; D002452:Cell Count; D049109:Cell Proliferation; D003514:Cyclohexylamines / Q000494:pharmacology; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D005260:Female; D006321:Heart / Q000196:embryology / Q000502:physiology*; D053823:Hedgehog Proteins / Q000819:agonists / Q000235:genetics / Q000378:metabolism; D057166:High-Throughput Screening Assays / Q000379:methods*; D007546:Isoquinolines / Q000494:pharmacology; D008297:Male; D032383:Myocytes, Cardiac / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012038:Regeneration; D015398:Signal Transduction; D013876:Thiophenes / Q000494:pharmacology; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism; D019076:Transgenes; D054875:Ubiquitination; D015027:Zebrafish / Q000235:genetics / Q000293:injuries / Q000502:physiology
chemical_list: D015415:Biomarkers; D002396:Catechols; D003514:Cyclohexylamines; D053823:Hedgehog Proteins; D007546:Isoquinolines; C436731:NBI 31772; D011993:Recombinant Fusion Proteins; C468918:SAG compound; D013876:Thiophenes; D016212:Transforming Growth Factor beta