MicroRNA-182 Inhibits the Proliferation and Migration of Human Corneal Epithelial Cells

Abstract

Objective: We investigated the in vivo and in vitro effects of microRNA-182 (miR-182) , which modulates post-transcriptional regulation of gene expression, on corneal epithelial cell proliferation, migration, and wound healing. Methods: In this experimental research, mouse corneal epithelial wound healing of five mouse was initiated by a scrape injury. Realtime reverse transcriptase polymerase chain reaction (RT-PCR) was performed to detect the expression level of miR-182 in the mouse corneal epithelium during the wound healing process (48 hours post scraping). Lipofectamine RNAiMAX reagent was used to transfect human corneal epithelial cells (HCECs) in vitro with either miR-182 or negative control RNA oligo. Cell proliferation assay (MTS), cell colony-forming assay, and flow cytometry were used to evaluate the effects of miR-182 on cell proliferation and cell cycle. An in vitro wound-healing assay (the HCECs were wounded by placing a scratch along the surface of each culture) was carried out to evaluate the effect of miR-182 on cell migration. Data were analyzed using independent t test. Results: The in vivo expression of miR-182 in experimentally wounded corneal epithelia was significantly lower than in the non-wounded controls (t=147.6, 79.2, 136.8, 41.3, 89.8, all P<0.001). In vitro, the relative number of cells in the experimental group transfected with miR-182 was (81±5)%, which was significantly less than that in the control group transfected with negative control RNA oligo, 100% (t=6.6, P=0.003). Further, the number of clones in the experimental group was remarkably decreased compared to that in the control group. The percentage of transfected cells in G1 arrest was (49±7)%, which was significantly higher than that in the control group, (35±4)% (t=-3.0, P=0.041). In addition, the migration distance of HCECs in the transfected cells, 99±12 μm, was shorter than in the control cells, 213±14 μm (t=10.8, P=0.001). Conclusions: miR-182 negatively regulates the corneal epithelial wound healing process by inhibiting corneal epithelial cell proliferation and migration. Key words: corneal wound healing; miR-182; corneal epithelium cell; proliferation; migration