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Microarray and electrophysiological studies of ion channel expression in undifferentiated and differentiated human skeletal muscle cells
Author(s) -
Lin Mingwei,
Wang YaJean,
Wu ShengNan
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.5.a536-d
Subject(s) - ion channel , skeletal muscle , patch clamp , cellular differentiation , chemistry , myosin , microbiology and biotechnology , electrophysiology , myocyte , myofilament , blot , voltage gated ion channel , gene expression , biology , endocrinology , gene , biochemistry , neuroscience , receptor
Ion currents functionally expressed in undifferentiated and differentiated human skeletal muscle cells (HSkMCs), were characterized in this study. A human ion channel and transporter gene array (SuperArrayTM®) was also probed to compare changes in ion channel expression between undifferentiated and differentiated cells. During one‐week culture in differentiating medium, HSkMCs were found to contract spontaneously. These cells underwent differentiation to exhibit actin and myosin myofilaments. Western blotting revealed increased expression in p27 after differentiation. In patch‐clamp studies, after being differentiated, the density of inwardly rectifying K + current was reduced and that of voltage‐gated Na + current and skeletal L‐type Ca 2+ current was significantly increased, while the density of voltage‐gated K + current and the activity of large‐conductance Ca 2+ ‐activated K + channels remained unaltered. Our microarray results showed that a group of ion channel genes were expressed in HSkMCs. The messages for KCNJx was relatively reduced in differentiated HSkMCs, while those of KCNAx and KCNHx was unaltered after differentiation. Taken together, the results indicate that spontaneous beating in differentiated HSkMCs is primarily related to the reduction of KCNJx expression.