Ozone oil promotes wound healing via increasing miR-21-5p-mediated inhibition of RASA1.

Skin wound is a very common type of injury and the healing process greatly affects the life quality of individuals. Ozone has been shown beneficial to wound healing with unclear mechanisms. Here, we tested the effect of ozone oil (OZ) on wound healing and investigated the underlying mechanisms. Mouse skin wound model and Masson staining were used to evaluate the effect of OZ on wound healing. Primary fibroblast culture was employed to assess the functions of OZ, miR-21-5p, and RASA1. QRT-PCR and western blot were used to determine expression levels of miR-21-5p, RASA1, α-SMA, and collagen I. CCK-8 assay and scratch wound healing assay were used to measure viability and migration of fibroblasts. Dual luciferase activity assay was performed to validate miR-21-5p/RASA1 interaction. OZ accelerated wound healing in mice and promoted proliferation and migration abilities of fibroblasts. miR-21-5p was increased while RASA1 was reduced during the wound healing and OZ treatment augmented those changes, as well as increased levels of α-SMA and collagen I. Knockdown of miR-21-5p suppressed those effects of OZ on fibroblasts. Furthermore, miR-21-5p directly targeted RASA1 mRNA and negatively regulated its expression. Overexpression of RASA1 inhibited fibroblast proliferation and migration as well as diminished α-SMA and collagen I protein expression. Additionally, RASA1 overexpression blocked the promotion of miR-21-5p overexpression on fibroblast viability and migration. In vivo, miR-21-5p facilitated wound healing while overexpression of RASA1 reversed the effect. OZ promoted wound healing by enhancing miR-21-5p-mediated RASA1 inhibition to increase fibroblast proliferation and migration.