title: Ascorbic acid enhances differentiation of embryonic stem cells into cardiac myocytes.
abstract: BACKGROUND
  Embryonic stem (ES) cells are capable of self-renewal and differentiation into cellular derivatives of all 3 germ layers. In appropriate culture conditions, ES cells can differentiate into specialized cells, including cardiac myocytes, but the efficiency is typically low and the process is incompletely understood.
  
  
  RESULTS
  We evaluated a chemical library for its potential to induce cardiac differentiation of ES cells in the absence of embryoid body formation. Using ES cells stably transfected with cardiac-specific alpha-cardiac myosin heavy chain (MHC) promoter-driven enhanced green fluorescent protein (EGFP), 880 compounds approved for human use were screened for their ability to induce cardiac differentiation. Treatment with ascorbic acid, also known as vitamin C, markedly increased the number of EGFP-positive cells, which displayed spontaneous and rhythmic contractile activity and stained positively for sarcomeric myosin and alpha-actinin. Furthermore, ascorbic acid induced the expression of cardiac genes, including GATA4, alpha-MHC, and beta-MHC in untransfected ES cells in a developmentally controlled manner. This effect of ascorbic acid on cardiac differentiation was not mimicked by the other antioxidants such as N-acetylcysteine, Tiron, or vitamin E.
  
  
  CONCLUSIONS
  Ascorbic acid induces cardiac differentiation in ES cells. This study demonstrates the potential for chemically modifying the cardiac differentiation program of ES cells.
authors.affiliation: Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Mass, USA.
authors.forename: Tomosaburo
authors.initials: T
authors.lastname: Takahashi
authors.forename: Bernadette
authors.initials: B
authors.lastname: Lord
authors.forename: P Christian
authors.initials: PC
authors.lastname: Schulze
authors.forename: Ryan M
authors.initials: RM
authors.lastname: Fryer
authors.forename: Satinder S
authors.initials: SS
authors.lastname: Sarang
authors.forename: Steven R
authors.initials: SR
authors.lastname: Gullans
authors.forename: Richard T
authors.initials: RT
authors.lastname: Lee
mesh_terms: D000185:Actinin / Q000032:analysis; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D001205:Ascorbic Acid / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D004622:Embryo, Mammalian / Q000166:cytology*; D004625:Embryo, Nonmammalian; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000235:genetics; D032383:Myocytes, Cardiac / Q000737:chemistry / Q000166:cytology* / Q000378:metabolism; D018995:Myosin Heavy Chains / Q000096:biosynthesis / Q000235:genetics; D009218:Myosins / Q000032:analysis; D012333:RNA, Messenger / Q000096:biosynthesis; D013234:Stem Cells / Q000187:drug effects / Q000502:physiology*
chemical_list: D000975:Antioxidants; D008164:Luminescent Proteins; D012333:RNA, Messenger; D000185:Actinin; D049452:Green Fluorescent Proteins; D018995:Myosin Heavy Chains; D009218:Myosins; D001205:Ascorbic Acid