Functional expression of ion channels in mesenchymal stem cells derived from umbilical cord vein.
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.
Park
Kyoung Sun
KS
Division of Molecular and Life Science, Hanyang University, Ansan, Korea.
Jung
Kyoung Hwa
KH
Kim
Seung Hyun
SH
Kim
Kyung Suk
KS
Choi
Mi Ran
MR
Kim
Yangmi
Y
Chai
Young Gyu
YG
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*
D007473:Ion Channels; D024681:Potassium Channels, Calcium-Activated; D024661:Potassium Channels, Inwardly Rectifying; D012333:RNA, Messenger; D015222:Sodium Channels