title: Characterization of functional ion channels in human cardiac c-kit+ progenitor cells.
abstract: Cardiac progenitor cells play an important role in cardiac repair and regeneration; however, their cellular biology and electrophysiology are not understood. The present study characterizes the functional ion channels in human cardiac c-kit(+) progenitor cells using whole-cell patch voltage-clamp, RT-PCR, and Western blots. We found that several ionic currents were present in human cardiac c-kit(+) progenitor cells, including a large-conductance Ca(2+)-activated K(+) current (BKCa) in 86 % of cells, an inwardly rectifying K(+) current (I Kir) in 84 % of cells, a transient outward K(+) current (I to) in 47 % of cells, a voltage-gated tetrodotoxin-sensitive Na(+) current (I Na,TTX) in 61 % of cells. Molecular identities of these ionic currents were determined with RT-PCR and Western-blot analysis. KCa.1.1 (for BKCa), Kir2.1 (for I Kir), Kv4.2 and Kv4.3 (for I to), Nav1.3 and Nav1.6 (for I Na.TTX) were abundantly expressed in human cardiac c-kit(+) progenitor cells, which do not resemble cardiomyocytes at all. These results demonstrate for the first time that four types of ionic currents including BKCa, I to, I Kir, and I Na.TTX, are heterogeneously present in human cardiac c-kit(+) cells, which may be involved in regulating cellular physiology.
authors.affiliation: Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China.
authors.forename: Ying-Ying
authors.initials: YY
authors.lastname: Zhang
authors.forename: Gang
authors.initials: G
authors.lastname: Li
authors.forename: Hui
authors.initials: H
authors.lastname: Che
authors.forename: Hai-Ying
authors.initials: HY
authors.lastname: Sun
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.forename: Wing-Kuk
authors.initials: WK
authors.lastname: Au
authors.forename: Guo-Sheng
authors.initials: GS
authors.lastname: Xiao
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.forename: Gui-Rong
authors.initials: GR
authors.lastname: Li
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000378:metabolism; D015153:Blotting, Western; D002478:Cells, Cultured; D005260:Female; D006801:Humans; D007473:Ion Channels / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D008297:Male; D008564:Membrane Potentials; D049990:Membrane Transport Modulators / Q000494:pharmacology; D008875:Middle Aged; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D019009:Proto-Oncogene Proteins c-kit / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013234:Stem Cells / Q000187:drug effects / Q000378:metabolism*; D013997:Time Factors
chemical_list: D015415:Biomarkers; D007473:Ion Channels; D049990:Membrane Transport Modulators; D012333:RNA, Messenger; D019009:Proto-Oncogene Proteins c-kit