Exosomes from adipose-derived mesenchymal stem cells can promote fibroblasts proliferation, migration, and collagen synthesis via activating Wnt/β-catenin signaling pathway during wound healing
Abstract Background Differentiation, migration, proliferation of skin fibroblasts are identified as the key factors during the cutaneous wound healing. Adipose-derived mesenchymal stem cells (ADMSCs) have been recorded as possible candidates for wound treatment because of their positive effect on the regeneration of many tissues. Exosomes derived from ADMSCs (ADMSC-Exos), an important signal transduction substance secreted by ADMSCs, have a similar role to ADMSCs in wound healing. However, the effects of ADMSC‐Exos on cutaneous wound healing remain to be unclear. In this study, we tried to explore the role and mechaninsm of ADMSC‐Exos during cutaneous wound healing. Methods Human skin fibroblasts (HSF) and ADMSCs were isolated from skin and adipose tissues of healthy person. ADMSC-Exos were purified from human ADMSCs culture medium by differential ultracentrifugation and identified by Electron microscopy, Nanoparticle tracking, and Western blotting assay. Fibroblasts were treated with different concentrations of ADMSC‐Exos. The proliferation and migration abilities of fibroblasts were analyzed by CCK-8 assay and scratch method. The synthesis of collagen type I (Col-I), collagen type III (Col-III), and α-smooth muscle actin (α-SMA) in fibroblasts was assessed by real-time quantitative polymerase chain reaction and Western blotting assay. A tensional wound model on rat back was used to evaluate the effect of ADMSC-Exos on wound healing. The expression levels of Wntb2 and β-catenin were analyzed by Western blotting and immunohistochemical assay. Results ADMSC-Exos were successfully obtained. ADMSC-Exos could significantly promote the migration and proliferation ability of fibroblasts in a dose-dependent manner in vitro. Compared with the treatment without ADMSC-Exos, the expression levels of Col-I and Col-III in fibroblasts treated with ADMSC-Exos were significantly increased, while the expression level of α-SMA is decreased. Besides, the enhanced expression of Wnt2b and β-catenin proteins confirmed the activation of the Wnt/β-catenin signaling pathway. Conclusions ADMSC-Exos can promote fibroblasts proliferation, migration, and collagen synthesis in a dose-dependent manner and may play a positive role in skin wound healing through Wnt/β-catenin signaling pathway. So our study elucidates part of the mechanism of ADMSC-Exos in wound healing, which illustrates the therapeutic potential of ADMSC-Exos as a new therapeutic approach to promote skin wound healing.