title: Identification and characterization of embryonic stem cell-derived pacemaker and atrial cardiomyocytes.
abstract: The aim of this study was to identify and functionally characterize cardiac subtypes during early stages of development. For this purpose, transgenic embryonic stem cells were generated using the alpha-myosin heavy chain promoter driving the expression of the enhanced green fluorescent protein (EGFP). EGFP-positive clusters of cells were first observed as early as 7 days of development, thus, even before the initiation of the contractile activity. Flow cytometry and single-cell fluorescence measurements evidenced large diversities of EGFP intensity. Patch-clamp experiments showed EGFP expression exclusively in pacemaker and atrial but not ventricular cells. The highest fluorescence intensities were detected in pacemaker-like cardiomyocytes. In accordance, multielectrode-array recordings of whole embryoid bodies confirmed that the pacemaker center coincided with strongly EGFP-positive areas. The cardiac subtypes displayed already at this early stage differential characteristics of electrical activity and ion channel expression. Thus, quantitation of the alpha-myosin heavy chain driven reporter gene expression allows identification and functional characterization of early cardiac subtypes.
authors.affiliation: Axiogenesis AG, Cologne, Germany. eugen.kolossov@axiogenesis.com
authors.forename: E
authors.initials: E
authors.lastname: Kolossov
authors.forename: Z
authors.initials: Z
authors.lastname: Lu
authors.forename: I
authors.initials: I
authors.lastname: Drobinskaya
authors.forename: N
authors.initials: N
authors.lastname: Gassanov
authors.forename: Y
authors.initials: Y
authors.lastname: Duan
authors.forename: H
authors.initials: H
authors.lastname: Sauer
authors.forename: O
authors.initials: O
authors.lastname: Manzke
authors.forename: W
authors.initials: W
authors.lastname: Bloch
authors.forename: H
authors.initials: H
authors.lastname: Bohlen
authors.forename: J
authors.initials: J
authors.lastname: Hescheler
authors.forename: B K
authors.initials: BK
authors.lastname: Fleischmann
mesh_terms: D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D002454:Cell Differentiation; D002469:Cell Separation; D002999:Clone Cells; D004594:Electrophysiology; D004622:Embryo, Mammalian / Q000166:cytology*; D005434:Flow Cytometry; D005453:Fluorescence; D015870:Gene Expression; D049452:Green Fluorescent Proteins / Q000032:analysis / Q000235:genetics; D006325:Heart Atria / Q000166:cytology* / Q000196:embryology; D006329:Heart Conduction System / Q000166:cytology* / Q000196:embryology; D051379:Mice; D008822:Mice, Transgenic; D018613:Microscopy, Confocal; D018721:Muscarinic Agonists / Q000494:pharmacology; D032383:Myocytes, Cardiac / Q000145:classification / Q000166:cytology* / Q000378:metabolism; D018995:Myosin Heavy Chains / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D013234:Stem Cells / Q000145:classification / Q000166:cytology* / Q000378:metabolism; D014162:Transfection; D024723:Ventricular Myosins / Q000235:genetics
chemical_list: D018721:Muscarinic Agonists; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D002217:Carbachol; D024723:Ventricular Myosins; D018995:Myosin Heavy Chains