Referenced in: none

Automatically associated channels: Kv1.2 , Kv1.4 , Kv2.1 , Kv3.1 , Kv4.3 , Slo1

Title: Potassium channel currents in rat mesenchymal stem cells and their possible roles in cell proliferation.

Authors: Shao-Ping Wang, Jian-An Wang, Rong-Hua Luo, Wen-Yu Cui, Hai Wang

Journal, date & volume: Clin. Exp. Pharmacol. Physiol., 2008 Sep , 35, 1077-84

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/18505444

Abstract
Mesenchymal stem cells (MSC) have shown considerable promise for the regeneration and repair of damaged tissue. However, the electrophysiological properties of K+ channels in MSC are not well established and little is known about the role of K+ channels in the regulation of MSC proliferation. We detected three distinct outward currents in MSC: (i) a delayed rectifier current (IK(DR)); (ii) a Ca2+-activated K+ current (IK(Ca)); and (iii) a transient outward K+ current (Ito). All three were present either alone or in combination in almost all cells (90%) investigated. However, 10% of cells did not express a functional current within physiological potentials. Reverse transcription-polymerase chain reaction was used to identify mRNA associated with functional ionic currents. Kv1.2 and Kv2.1 were associated with IK(DR); Slo and KCNN4 were associated with IK(Ca); and Kv1.4 and Kv4.3 were associated with Ito. The Kv channel blockers amiodarone, tetraethylammonium and verapamil, as well as increased extracellular K+ levels, inhibited proliferation of cultured MSC. In MSC treated with Kv channel blockers or an increased extracellular concentration of K+, the proportion of cells in the S phase decreased significantly and the proportion of cells in the G(0)/G(1) phase tended to increase, indicating that the cells were prevented from entering the S phase of the cell cycle. Our findings suggest that rat MSC heterogeneously express distinct types of K+ current, of which the voltage-gated IK(DR)-like K+ current is most common. Kv channel activity modulates the progression of the cell cycle, affecting the proliferation of MSC.