Open AccessCell cycle‐dependent expression of potassium channels and cell proliferation in rat mesenchymal stem cells from bone marrow
Author(s) -
Deng X. L.,
Lau C. P.,
Lai K.,
Cheung K. F.,
Lau G. K.,
Li G. R.
Publication year - 2007
Publication title -
cell proliferation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.647
H-Index - 74
eISSN - 1365-2184
pISSN - 0960-7722
DOI - 10.1111/j.1365-2184.2007.00458.x
Subject(s) - mesenchymal stem cell , cell cycle , microbiology and biotechnology , cell growth , cell , biology , flow cytometry , membrane potential , bone marrow , chemistry , immunology , biophysics , biochemistry
. Objective : Recently, our team has demonstrated that voltage‐gated delayed rectifier K + current (IK DR ) and Ca 2+ ‐activated K + current (I KCa ) are present in rat bone marrow‐derived mesenchymal stem cells; however, little is known of their physiological roles. The present study was designed to investigate whether functional expression of IK DR and I KCa would change with cell cycle progression, and whether they could regulate proliferation in undifferentiated rat mesenchymal stem cells (MSCs). Materials and Methods : Membrane potentials and ionic currents were recorded using whole‐cell patch clamp technique, cell cycling was analysed by flow cytometry, cell proliferation was assayed with DNA incorporation method and the related genes were down‐regulated by RNA interference (RNAi) and examined using RT‐PCR. Results : It was found that membrane potential hyperpolarized, and cell size increased during the cell cycle. In addition, IK DR decreased, while I KCa increased during progress from G 1 to S phase. RT‐PCR revealed that the mRNA levels of Kv1.2 and Kv2.1 (likely responsible for IK DR ) reduced, whereas the mRNA level of KCa3.1 (responsible for intermediate‐conductance I KCa ) increased with the cell cycle progression. Down‐regulation of Kv1.2, Kv2.1 or KCa3.1 with the specific RNAi, targeted to corresponding gene inhibited proliferation of rat MSCs. Conclusion : These results demonstrate that membrane potential, IK DR and I KCa channels change with cell cycle progression and corresponding alteration of gene expression. IK DR and intermediate‐conductance I KCa play an important role in maintaining membrane potential and they participate in modulation of proliferation in rat MSCs.