Referenced in: none

Automatically associated channels: HCN3 , HCN4 , Kv10.1 , Slo1

Title: Electrophysiological properties of prion-positive cardiac progenitors derived from murine embryonic stem cells.

Authors: Hiroshi Fujii, Yu Ikeuchi, Yasutaka Kurata, Nobuhito Ikeda, Udin Bahrudin, Peili Li, Yuji Nakayama, Ryo Endo, Akira Hasegawa, Kumi Morikawa, Junichiro Miake, Akio Yoshida, Kyoko Hidaka, Takayuki Morisaki, Haruaki Ninomiya, Yasuaki Shirayoshi, Kazuhiro Yamamoto, Ichiro Hisatome

Journal, date & volume: Circ. J., 2012 , 76, 2875-83

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/22972200

Abstract
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.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.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.