MicroRNA-124 represses wound healing by targeting SERP1 and inhibiting the Wnt/β-catenin pathway

Background. Wound healing is a complex process which restores cellular structures and tissue layers after their destruction. Accumulating evidence has proven that microRNAs (miRs) are involved in wound healing. Objectives. The aim of the study was to research the role of miR-124 in wound healing. Material and methods. Keratinocytes were respectively transfected with miR-124 mimic, scrambled miRNA (a negative control of miR-124 mimic: mimic NC), antisense oligonucleotides against miR-124 (ASOmiR-124), or a negative control of ASO-miR-124 (ASO-NC), and then cell viability, colony formation, cell cycle, expression of cell cycle-associated proteins, and collagen content were all evaluated. The target gene of miR-124 was predicted using TargetScan and verified with luciferase assay. Subsequently, the effects of target gene overexpression on cell viability, colony formation and collagen synthesis were all evaluated. Finally, the expression levels of key kinases in the Wnt/beta-catenin pathway were detected using western blot analysis. Results. Cell viability, colony formation, expression levels of cell cycle-associated proteins, and collagen content were all significantly reduced by miR-124 overexpression. As predicted using bioinformatics and validated with luciferase assay, stress-associated endoplasmic reticulum protein 1 (SERP)) is a target gene of miR-124. Meanwhile, the miR-124 mimic-induced decrease in cell viability, colony formation and collagen synthesis was reversed by SERP1 overexpression. Furthermore, the miR-124 mimic obviously upregulated glycogen synthase kinase 3 beta (GSK-3 beta) while downregulating beta-catenin, T cell transcription factor 4 (TCF-4) and leukemia enhancer factor 1 (LEF-1). Additionally, all the effects of ASO-miR-124 were the opposite of those of the miR-124 mimic. Conclusions. We found that miR-124 inhibited keratinocyte proliferation, collagen biosynthesis and activation of Wnt/beta-catenin by targeting SERP1.