MicroRNA-149 contributes to scarless wound healing by attenuating inflammatory response.

A fibrotic or pathological scar is an undesired consequence of skin wound healing and may trigger a series of problems. An attenuated inflammatory response is a significant characteristic of fetal skin wound healing, which can contribute to the scarless healing of fetal skin. According to deep sequencing data, microRNA‑149 (miR‑149) expression was increased in mid-gestational compared with that in late‑gestational fetal skin keratinocytes. It was demonstrated that overexpression of miR‑149 in HaCaT cells can downregulate the expression of pro‑inflammatory cytokines interleukin (IL)‑1α, IL‑1β, and IL‑6 at basal levels and in inflammatory conditions. Furthermore, miR‑149 was revealed to indirectly accelerate transforming growth factor‑β3 and collagen type III expression in fibroblasts, which are essential cells in extracellular matrix remodeling. In a rat skin wound model, miR‑149 improved the quality of the arrangement of collagen bundles and reduced inflammatory cell infiltration during skin wound healing. These results indicate that miR‑149 may be a potential regulator in improving the quality of skin wound healing.