Effect of Big Conductance Ca2+-Activated K+ Channel on Proliferations of Rat Bone Marrow Mesenchymal Stem Cells

Abstract: To investigate the effect of big conductance Ca2+-activated K+ channel (BKca) on proliferation of rat bone marrow mesenchymal stem cells (BMSCs) and explore relevant mechanism， BMSCs were isolated from rats bone marrow and expanded in vitro for three generations. BMSCs were treated with BKca specific opener (NS1619) and blocker (IBTX) separately. Proliferative activity and colony formation ability were determined by MTT and Tablet cloning. Cell cycle distribution and apoptosis were analyzed by flow cytometry. Western blot and Q-PCR were used to detect the mRNA and protein levels of cyclin D1. Membrane ionic currents were recorded by whole-cell patch clamp technique. Compared with control group， the group of NS1619 exhibited a higher proliferative activity， colony formation ability and lower apoptosis rate. Additionally， the amplitude of outward K+ currents were enhanced in membrane. The results of flow cytometry， Q-PCR and Western blot suggested that activation of BKca facilitated cell progress from G1 to S phase and improved the expression levels of mRNA and protein of cyclin D1. However， the result of blockade of BKca was contrary to activation of BKca. According to our speculation， BKca could promote the proliferation of rat BMSCs. The mechanism might be related to the regulation of cell cycle. Furthermore， the electrophysiology properties of BKca play a crucial role in cell proliferation.

CSTR: 32200.14.cjcb.2014.03.0004