Acceleration of Cutaneous Wound Healing by Suppression of Large Conductance Ca2+-Activated K+ Channels

Abstract

Many kinds of K+ channels are involved in the regulation of cell migration and proliferation, which are required for the processes of wound healing. However, the role of K+ channels on cutaneous wound healing has not yet been reported. Here, we demonstrate that inhibition of large conductance Ca2+-activated K+ (BKCa) channels expressed in human epidermal keratinocyte facilitate cutaneous wound healing by activating both cell migration and proliferation. In the group treated with 25 mM KCl, in vivo wound healing was facilitated more rapidly than that in control group. In vitro assay of wound healing showed that 25 mM KCl significantly increased wound closure in keratinocytes after creation of linear wound with ∼200 ∈1/4m wide defect. KCl (25 mM) promoted processes of cell migration and proliferation. BKCa and two-pore domain K+ channels were recorded in the keratinocytes by using patch-clamp technique. The BKCa channel, among these K+ channels, is the most frequently observed in cell-attached mode. NS1619, a BKCa channel opener, inhibited the proliferation and migration of keratinocytes in a dose- and time-dependent manner. Charybdotoxin and iberiotoxin, BKCa channel blockers, facilitated both cell proliferation and migration by 10±7% and 30±4%, respectively. Cutaneous wound healing was also facilitated by siRNA against BKCa (BKCa/siRNA). The migration and proliferation were more enhanced by cotransfection with BKCa/siRNA and TASK-1/siRNA. BKCa channel blockers activated PKC and ERK in a time-dependent manner. These results show that BKCa and TASK-1 channels regulate proliferation and migration of human epidermal keratinocytes by activation of PKC-ERK pathway and indicate that BKCa channel could be a molecular target for regulation of cell proliferation and migration.