title: Functional expression of ion channels in mesenchymal stem cells derived from umbilical cord vein.
abstract: Mesenchymal stem cells have the ability to renew and differentiate into various lineages of mesenchymal tissues. We used undifferentiated human mesenchymal-like stem cells from human umbilical cord vein (hUC-MSCs), a cell line which contains several mesenchymal cell markers. We characterized functional ion channels in cultured hUC-MSCs with whole-cell patch clamp and reverse transcription-polymerase chain reaction (RT-PCR). Three types of outward current were found in these cells: the Ca(2+)-activated K(+) channel (IK(Ca)), a transient outward K(+) current (I(to)), and a delayed rectifier K(+) current (IK(DR)). IK(Ca) and IK(DR) were totally suppressed by tetraethylammonium, and IK(Ca) was sensitive to a specific blocker, iberiotoxin. I(to) was inhibited by 4-aminopyridine. Another type of inward rectifier K(+) current (K(ir)) was also detected in approximately 5% of hUC-MSCs. Elevation of external potassium ion concentration increased the K(ir) current amplitude and positively shifted its reversal potential. In addition, inward Na(+) current (I(Na)) was found in these cells ( approximately 30%); the current was blocked by tetrodotoxin and verapamil. In the RT-PCR analysis, Kv1.1, Kv4.2, Kv1.4, Kir2.1, heag1, MaxiK, hNE-Na, and TWIK-1 were detected. These results suggested that multiple functional ion channel currents, IK(Ca), IK(DR), I(to), I(Na), and K(ir), are expressed in hUC-MSCs. Disclosure of potential conflicts of interest is found at the end of this article.
authors.affiliation: Division of Molecular and Life Science, Hanyang University, Ansan, Korea.
authors.forename: Kyoung Sun
authors.initials: KS
authors.lastname: Park
authors.forename: Kyoung Hwa
authors.initials: KH
authors.lastname: Jung
authors.forename: Seung Hyun
authors.initials: SH
authors.lastname: Kim
authors.forename: Kyung Suk
authors.initials: KS
authors.lastname: Kim
authors.forename: Mi Ran
authors.initials: MR
authors.lastname: Choi
authors.forename: Yangmi
authors.initials: Y
authors.lastname: Kim
authors.forename: Young Gyu
authors.initials: YG
authors.lastname: Chai
mesh_terms: D002478:Cells, Cultured; D006801:Humans; D007473:Ion Channels / Q000235:genetics / Q000378:metabolism*; D059630:Mesenchymal Stem Cells / Q000378:metabolism* / Q000502:physiology; D018408:Patch-Clamp Techniques; D024681:Potassium Channels, Calcium-Activated / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D024661:Potassium Channels, Inwardly Rectifying / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D012333:RNA, Messenger / Q000378:metabolism; D015222:Sodium Channels / Q000378:metabolism; D014471:Umbilical Veins / Q000166:cytology / Q000378:metabolism*
chemical_list: D007473:Ion Channels; D024681:Potassium Channels, Calcium-Activated; D024661:Potassium Channels, Inwardly Rectifying; D012333:RNA, Messenger; D015222:Sodium Channels