miR-186-5p targets TGF beta R2 to inhibit RAW264.7 cell migration and proliferation during mouse skin wound healing

Background: Active peptides play a vital role in the development of new drugs and the identification and discovery of drug targets. As the first reported native peptide homodimer with pro-regenerative potency, OA-GP11d could potentially be used as a novel molecular probe to help elucidate the molecular mechanism of skin wound repair and provide new drug targets. Methods: Bioinformatics analysis and luciferase assay were adopted to determine microRNAs (miRNAs) and its target. The prohealing potency of the miRNA was determined by MTS and a Transwell experiment against mouse macrophages. Enzymelinked immunosorbent assay, realtime polymerase chain reaction, and western blotting were performed to explore the molecular mechanisms. Results: In this study, OA-GP11d was shown to induce Mus musculus microRNA-186-5p (mmu-miR-186-5p) down-regulation. Results showed that miR-186-5p had a negative effect on macrophage migration and proliferation as well as a targeted and negative effect on TGF-beta type II receptor (TGF beta R2) expression and an inhibitory effect on activation of the downstream SMAD family member 2 (Smad2) and protein-p38 kinase signaling pathways. Importantly, delivery of a miR-186-5p mimic delayed skin wound healing in mice. Conclusion: miR-186-5p regulated macrophage migration and proliferation to delay wound healing through the TGF beta R2/Smad2/p38 molecular axes, thus providing a promising new pro-repair drug target.