title: ISL1 protein transduction promotes cardiomyocyte differentiation from human embryonic stem cells.
abstract: BACKGROUND
  Human embryonic stem cells (hESCs) have the potential to provide an unlimited source of cardiomyocytes, which are invaluable resources for drug or toxicology screening, medical research, and cell therapy. Currently a number of obstacles exist such as the insufficient efficiency of differentiation protocols, which should be overcome before hESC-derived cardiomyocytes can be used for clinical applications. Although the differentiation efficiency can be improved by the genetic manipulation of hESCs to over-express cardiac-specific transcription factors, these differentiated cells are not safe enough to be applied in cell therapy. Protein transduction has been demonstrated as an alternative approach for increasing the efficiency of hESCs differentiation toward cardiomyocytes.
  
  
  METHODS
  We present an efficient protocol for the differentiation of hESCs in suspension by direct introduction of a LIM homeodomain transcription factor, Islet1 (ISL1) recombinant protein into the cells.
  
  
  RESULTS
  We found that the highest beating clusters were derived by continuous treatment of hESCs with 40 µg/ml recombinant ISL1 protein during days 1-8 after the initiation of differentiation. The treatment resulted in up to a 3-fold increase in the number of beating areas. In addition, the number of cells that expressed cardiac specific markers (cTnT, CONNEXIN 43, ACTININ, and GATA4) doubled. This protocol was also reproducible for another hESC line.
  
  
  CONCLUSIONS
  This study has presented a new, efficient, and reproducible procedure for cardiomyocytes differentiation. Our results will pave the way for scaled up and controlled differentiation of hESCs to be used for biomedical applications in a bioreactor culture system.
authors: Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, Tehran, Iran.
authors: Hananeh
authors: H
authors: Fonoudi
authors: Meghdad
authors: M
authors: Yeganeh
authors: Faranak
authors: F
authors: Fattahi
authors: Zaniar
authors: Z
authors: Ghazizadeh
authors: Hassan
authors: H
authors: Rassouli
authors: Mehdi
authors: M
authors: Alikhani
authors: Bahareh Adhami
authors: BA
authors: Mojarad
authors: Hossein
authors: H
authors: Baharvand
authors: Ghasem Hosseini
authors: GH
authors: Salekdeh
authors: Nasser
authors: N
authors: Aghdami
mesh_terms: D002454:Cell Differentiation / Q000187:drug effects* / Q000235:genetics; D002460:Cell Line; D053595:Embryonic Stem Cells / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism; D015870:Gene Expression; D006801:Humans; D060850:LIM-Homeodomain Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D032383:Myocytes, Cardiac / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism; D010539:Permeability; D055550:Protein Stability; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D060850:LIM-Homeodomain Proteins; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; C063843:insulin gene enhancer binding protein Isl-1
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