Osteoarthritis (OA) is a chronic health condition. MicroRNAs (miRs) are critical in chondrocyte apoptosis in OA. We aimed to investigate the mechanism of miR-130b in OA progression. Bone marrow mesenchymal stem cells (BMSCs) and chondrocytes were first extracted. Chondrogenic differentiation of BMSCs was carried out and verified. Chondrocytes were stimulated with interleukin (IL)-1b to imitate OA condition in vitro. The effect of miR-130b on the viability, inflammation, apoptosis, and extracellular matrix of OA chondrocytes was studied. The target gene of miR-130b was predicted and verified. Rescue experiments were performed to further study the underlying downstream mechanism of miR-130b in OA. miR-130b first increased and drastically reduced during chondrogenic differentiation of BMSCs and in OA chondrocytes, respectively, while IL-1b stimulation resulted in increased miR-130b expression in chondrocytes. miR-130b inhibitor promoted chondrogenic differentiation of BMSCs and chondrocyte growth and inhibited the levels of inflammatory factors. miR-130b targeted SOX9. Overexpression of SOX9 facilitated BMSC chondrogenic differentiation and chondrocyte growth, while siRNA-SOX9 contributed to the opposite trends. Silencing of SOX9 significantly attenuated the pro-chondrogenic effects of miR-130b inhibitor on BMSCs. Overall, miR-130b inhibitor induced chondrogenic differentiation of BMSCs and chondrocyte growth by targeting SOX9.

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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.