title: Electrophysiological properties of prion-positive cardiac progenitors derived from murine embryonic stem cells.
abstract: BACKGROUND
  The prion protein (PrP) has been reported to serve as a surface maker for isolation of cardiomyogenic progenitors from murine embryonic stem (ES) cells. Although PrP-positive cells exhibited automaticity, their electrophysiological characteristics remain unresolved. The aim of the present study was therefore to investigate the electrophysiological properties of PrP-positive cells in comparison with those of HCN4p-or Nkx2.5-positive cells.
  
  
  RESULTS
  Differentiation of AB1, HCN5p-EGFP and hcgp7 ES cells into cardiac progenitors was induced by embryoid body (EB) formation. EBs were dissociated and cells expressing PrP, HCN4-EGFP and/or Nkx2.5-GFP were collected via flow cytometry. Sorted cells were subjected to reverse transcriptase-polymerase chain reaction, immunostaining and patch-clamp experiments. PrP-positive cells expressed mRNA of undifferentiation markers, first and second heart field markers, and cardiac-specific genes and ion channels, indicating their commitment to cardiomyogenic progenitors. PrP-positive cells with automaticity showed positive and negative chronotropic responses to isoproterenol and carbamylcholine, respectively. Hyperpolarization-activated cation current (I(f)) was barely detectable, whereas Na(+) and L-type Ca(2+) channel currents were frequently observed. Their spontaneous activity was slowed by inhibition of sarcoplasmic reticulum Ca(2+) uptake and release but not by blocking I(f). The maximum diastolic potential of their spontaneous firings was more depolarized than that of Nkx2.5-GFP-positive cells.
  
  
  CONCLUSIONS
  PrP-positive cells contained cardiac progenitors that separated from the lineage of sinoatrial node cells. PrP can be used as a marker to enrich nascent cardiac progenitors.
authors.affiliation: Division of Regenerative Medicine and Therapeutics, Institute of Regenerative Medicine and Biofunction, Tottori University Graduate School of Medical Science, Yonago, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Fujii
authors.forename: Yu
authors.initials: Y
authors.lastname: Ikeuchi
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Kurata
authors.forename: Nobuhito
authors.initials: N
authors.lastname: Ikeda
authors.forename: Udin
authors.initials: U
authors.lastname: Bahrudin
authors.forename: Peili
authors.initials: P
authors.lastname: Li
authors.forename: Yuji
authors.initials: Y
authors.lastname: Nakayama
authors.forename: Ryo
authors.initials: R
authors.lastname: Endo
authors.forename: Akira
authors.initials: A
authors.lastname: Hasegawa
authors.forename: Kumi
authors.initials: K
authors.lastname: Morikawa
authors.forename: Junichiro
authors.initials: J
authors.lastname: Miake
authors.forename: Akio
authors.initials: A
authors.lastname: Yoshida
authors.forename: Kyoko
authors.initials: K
authors.lastname: Hidaka
authors.forename: Takayuki
authors.initials: T
authors.lastname: Morisaki
authors.forename: Haruaki
authors.initials: H
authors.lastname: Ninomiya
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Shirayoshi
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Ichiro
authors.initials: I
authors.lastname: Hisatome
mesh_terms: D000200:Action Potentials; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002454:Cell Differentiation; D002460:Cell Line; D019070:Cell Lineage; D002469:Cell Separation / Q000379:methods; D018920:Coculture Techniques; D054815:Cyclic Nucleotide-Gated Cation Channels / Q000235:genetics / Q000378:metabolism; D053595:Embryonic Stem Cells / Q000378:metabolism*; D005434:Flow Cytometry; D018507:Gene Expression Regulation, Developmental; D007150:Immunohistochemistry; D051379:Mice; D057507:Mice, 129 Strain; D009200:Myocardial Contraction; D032383:Myocytes, Cardiac / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D010507:Periodicity; D011328:Prions / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014162:Transfection
chemical_list: D015415:Biomarkers; D054815:Cyclic Nucleotide-Gated Cation Channels; D011328:Prions; D012333:RNA, Messenger; D014157:Transcription Factors