title: Developmental changes in cardiomyocytes differentiated from human embryonic stem cells: a molecular and electrophysiological approach.
abstract: Cardiomyocytes derived from human embryonic stem cells constitute a promising cell source for the regeneration of damaged hearts. The assessment of their in vitro functional properties is mandatory to envisage appropriate cardiac cell-based therapies. In this study, we characterized human embryonic stem cell-derived cardiomyocytes over a 3-month period, using patch-clamp or intracellular recordings to assess their functional maturation and reverse transcriptase-polymerase chain reaction to evaluate the expression of ion channel-encoding subunits. I(to1) and I(K1), the transient outward and inward rectifier potassium currents, were present in cardiomyocytes only, whereas the rapid delayed rectifier potassium current (I(Kr)), pacemaker current (I(f)), and L-type calcium current (I(Ca,L)) could be recorded both in undifferentiated human embryonic stem cells and in cardiomyocytes. Most of the currents underwent developmental maturation in cardiomyocytes, as assessed by modifications in current density (I(to1), I(K1), and I(Ca,L)) and properties (I(f)). Ion-channel mRNAs were always present when the current was recorded. Intracellular recordings in spontaneously beating clusters of cardiomyocytes revealed changes in action potential parameters and in response to pharmacological tools according to time of differentiation. In summary, human embryonic stem cell-derived cardiomyocytes mature over time during in vitro differentiation, approaching an adult phenotype. Disclosure of potential conflicts of interest is found at the end of this article.
authors.affiliation: Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata, University of Firenze, Firenze, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Sartiani
authors.forename: Esther
authors.initials: E
authors.lastname: Bettiol
authors.forename: Francesca
authors.initials: F
authors.lastname: Stillitano
authors.forename: Alessandro
authors.initials: A
authors.lastname: Mugelli
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Cerbai
authors.forename: Marisa E
authors.initials: ME
authors.lastname: Jaconi
mesh_terms: D000818:Animals; D020746:Calcium Channels, L-Type / Q000378:metabolism; D002454:Cell Differentiation; D002478:Cells, Cultured; D054815:Cyclic Nucleotide-Gated Cation Channels; D003971:Diastole; D004594:Electrophysiology; D053595:Embryonic Stem Cells / Q000166:cytology* / Q000378:metabolism*; D005786:Gene Expression Regulation; D006801:Humans; D064428:Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels; D051379:Mice; D008954:Models, Biological; D032383:Myocytes, Cardiac / Q000166:cytology* / Q000378:metabolism*; D015221:Potassium Channels / Q000235:genetics / Q000378:metabolism; D024661:Potassium Channels, Inwardly Rectifying / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013997:Time Factors
chemical_list: D020746:Calcium Channels, L-Type; D054815:Cyclic Nucleotide-Gated Cation Channels; D064428:Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels; D015221:Potassium Channels; D024661:Potassium Channels, Inwardly Rectifying; D012333:RNA, Messenger