title: Identification of chemicals inducing cardiomyocyte proliferation in developmental stage-specific manner with pluripotent stem cells.
abstract: BACKGROUND
  The proliferation of cardiomyocytes is highly restricted after postnatal maturation, limiting heart regeneration. Elucidation of the regulatory machineries for the proliferation and growth arrest of cardiomyocytes is imperative. Chemical biology is efficient to dissect molecular mechanisms of various cellular events and often provides therapeutic potentials. We have been investigating cardiovascular differentiation with pluripotent stem cells. The combination of stem cell and chemical biology can provide novel approaches to investigate the molecular mechanisms and manipulation of cardiomyocyte proliferation.
  
  
  RESULTS
  To identify chemicals that regulate cardiomyocyte proliferation, we performed a screening of a defined chemical library based on proliferation of mouse pluripotent stem cell-derived cardiomyocytes and identified 4 chemical compound groups: inhibitors of glycogen synthase kinase-3, p38 mitogen-activated protein kinase, and Ca(2+)/calmodulin-dependent protein kinase II, and activators of extracellular signal-regulated kinase. Several appropriate combinations of chemicals synergistically enhanced proliferation of cardiomyocytes derived from both mouse and human pluripotent stem cells, notably up to a 14-fold increase in mouse cardiomyocytes. We also examined the effects of identified chemicals on cardiomyocytes in various developmental stages and species. Whereas extracellular signal-regulated kinase activators and Ca(2+)/calmodulin-dependent protein kinase II inhibitors showed proliferative effects only on cardiomyocytes in early developmental stages, glycogen synthase kinase-3 and p38 mitogen-activated protein kinase inhibitors substantially and synergistically induced re-entry and progression of cell cycle in neonatal but also as well as adult cardiomyocytes.
  
  
  CONCLUSIONS
  Our approach successfully uncovered novel molecular targets and mechanisms controlling cardiomyocyte proliferation in distinct developmental stages and offered pluripotent stem cell-derived cardiomyocytes as a potent tool to explore chemical-based cardiac regenerative strategies.
authors.affiliation: Division of Cardiology, The Johns Hopkins University School of Medicine, Baltimore, MD.
authors.forename: Hideki
authors.initials: H
authors.lastname: Uosaki
authors.forename: Ajit
authors.initials: A
authors.lastname: Magadum
authors.forename: Kinya
authors.initials: K
authors.lastname: Seo
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Fukushima
authors.forename: Ayako
authors.initials: A
authors.lastname: Takeuchi
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Nakagawa
authors.forename: Kara White
authors.initials: KW
authors.lastname: Moyes
authors.forename: Genta
authors.initials: G
authors.lastname: Narazaki
authors.forename: Koichiro
authors.initials: K
authors.lastname: Kuwahara
authors.forename: Michael
authors.initials: M
authors.lastname: Laflamme
authors.forename: Satoshi
authors.initials: S
authors.lastname: Matsuoka
authors.forename: Norio
authors.initials: N
authors.lastname: Nakatsuji
authors.forename: Kazuwa
authors.initials: K
authors.lastname: Nakao
authors.forename: Chulan
authors.initials: C
authors.lastname: Kwon
authors.forename: David A
authors.initials: DA
authors.lastname: Kass
authors.forename: Felix B
authors.initials: FB
authors.lastname: Engel
authors.forename: Jun K
authors.initials: JK
authors.lastname: Yamashita
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D015153:Blotting, Western; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation; D002460:Cell Line; D049109:Cell Proliferation; D053595:Embryonic Stem Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D020536:Enzyme Activators / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D038362:Glycogen Synthase Kinase 3 / Q000037:antagonists & inhibitors / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D051379:Mice; D032383:Myocytes, Cardiac / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D039904:Pluripotent Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D020536:Enzyme Activators; D004791:Enzyme Inhibitors; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D048049:Extracellular Signal-Regulated MAP Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D038362:Glycogen Synthase Kinase 3
keywords: cell proliferation; embryonic stem cells; myocytes, cardiac