Inhibition of miR-205 impairs the wound-healing process in human corneal epithelial cells by targeting KIR4.1 (KCNJ10)

Abstract

Purpose. The aim of the study was to test the hypotheses that injury stimulates the expression of miR-205, which in turn inhibits KCNJ10 channels by targeting its 3′ UTR, thereby facilitating the wound-healing process in human corneal epithelial cells (HCECs). Methods. A stem-loop qRT-PCR was used to examine the miR-205 expression. BrdU cell proliferation assay and wound scratch assay were applied to measure the effect of miR-205 mimic or antagomer in HCECs. The patch-clamp technique, dual luciferase reporter assay, and Western blot analysis were employed to test whether miR-205 regulates KCNJ10, one of the target genes of miR-205. Both of the primary human and mouse corneal epithelial cells (pH/MCECs) were employed to further confirm the observations obtained in HCECs. Results. The scratch injury in pH/MCECs increased the expression of miR-205 and decreased the expression of KCNJ10 within 24 hours. The notion that miR-205 may target KCNJ10 was supported by dual luciferase reporter assay showing an inhibition effect of miR-205 on 3′ UTR of KCNJ10. Application of miR-205 antagomer significantly delayed the regrowth in wounded HCECs. However, inhibition of KCNJ10 partially abolished the effect from miR-205 antagomer and restored the healing process. Moreover, overexpression miR-205 antagomer enhanced the protein expression of KCNJ10 but not KCNJ16. In addition, patch-clamp demonstrated that inhibition of endogenous miR-205 expression increased Ba2+-sensitive inwardly rectifying K+ channels. In addition, an electrophysiological study of pHCECs showed the presence of KCNJ10-like 20 pS K+ channels and scratch injury significantly decreased the Ba2+-sensitive inwardly rectifying K+ currents. Conclusions. miR-205 stimulates wound healing by inhibiting its target gene KCNJ10. © 2013 The Association for Research in Vision and Ophthalmology, Inc.