Exosomes Derived from Dental Pulp Stem Cells Accelerate Cutaneous wound Healing by Enhancing Angiogenesis via Cdc42/p38 MAPK Pathway

Background: Skin wound healing is a common challenging clinical problem and need advanced treatment strategies. Here, we investigated the therapeutic effects of exosomes derived from dental pulp stem cells (DPSC-Exos) on cutaneous wound healing and the underlying mechanisms. Methods: The effects of DPSC-Exos on cutaneous wound healing in mice were examined by measuring wound closure rates, histological and immunohistochemical analysis. A series of functional assays were performed to evaluate the effects of DPSC-Exos on the angiogenic activities of human umbilical vein endothelial cells (HUVECs) in vitro. TMT-based quantitative proteomic analysis of DPSCs and DPSC-Exos was performed. Gene ontology (GO) and KEGG pathway enrichment analysis were used to evaluate biological functions and pathways for the differentially expressed proteins in DPSC-Exos. Western blot was used to assess the protein levels of Cdc42 and p38 in DPSC-Exos-induced angiogenesis of HUVECs. SB203580, a p38 MAPK signaling pathway inhibitor, was employed to verify the role of p38 MAPK pathway in these processes.Results: Histological and immunohistochemical staining revealed that DPSC-Exos accelerated wound healing by improving neovascularization. DPSC-Exos augmented the migration, proliferation, and capillary formation capacity of HUVECs. Proteomic data demonstrated that proteins contained in DPSC-Exos regulated vasculature development and angiogenesis. Pathway analysis showed that proteins expressed in DPSC-Exos were involved in several pathways including MAPK pathway. Western blotting demonstrated that DPSC-Exos increased the protein levels of Cdc42 and phosphorylation of p38 in HUVECs. SB203580 suppressed the angiogenesis of HUVECs induced by DPSC-Exos.Conclusions: DPSC-Exos could accelerate cutaneous wound healing by enhancing the angiogenic properties of HUVECs via Cdc42/p38 MAPK signaling pathway.