Effect Of Big Conductance Ca²⁺-activated K⁺Channel On Proliferations Of Rat Bone Marrow Mesenchymal Stem Cells

Objective: To investigate the effect of big conductance Ca2+-activatedK+channel (BKca) on proliferation of rat bone marrow mesenchymal stemcells (BMSCs) in vitro and explore relevant mechanism.Methods: BMSCs were isolated from rats bone marrow and expandedin vitro for three generations. BMSCs were treated with BKca specificopener (NS1619) and blocker(IBTX) separately. BMSCs were randomlydivided into4groups:Control group,DMSO group(Solvent controlgroup),NS1619group and IBTX group.Proliferative activity and colonyformation ability were determined by MTT and Tablet cloning. Cell cycledistribution and apoptosis were analyzed by flow cytometry. Western blotand Q-PCR were used to detect the mRNA and protein levels of cyclin D1.Membrane ionic currents were recorded by whole-cell patch clamptechnique.Results:（1） BMSCs were obtained from rats bone marrowsuccessfully and expanded in vitro for three generations.（2）Compared withcontrol group the amplitude of outward K+currents were enhanced inMembrane(P<0.01).(3)the group of NS1619exhibited a higher proliferative activity and colony formation ability(P<0.05) and lowerapoptosis rate(P<0.05).(4)The results of flow cytometry suggested thatactivation of BKca facilitated cell progress from G1to S phase.(5) Westernblot and Q-PCR suggested that the NS1619group has a Higher expressionlevels of mRNA and protein of cyclinD1.(6)However, the result ofblockade of BKca was contrary to activation of BKca. Additionally,there isno Significant differences between control group an DMSO group.Conclusion: According to our speculation,(1)BKca could promote theproliferation of rat BMSCs, The mechanism might be related to theregulation of cell cycle.(2)The electrophysiology properties of BKca playa crucial role in cell proliferation.