MSC-derived exosomal circMYO9B accelerates diabetic wound healing by promoting angiogenesis through the hnRNPU/CBL/KDM1A/VEGFA axis.

Diabetic foot ulcer (DFU) is a common but devastating complication of diabetes mellitus and might ultimately lead to amputation. Elucidating the regulatory mechanism of wound healing in DFU is quite important for developing DFU management strategies. Here, we show, mecenchymal stem cell (MSC)-derived exosomes promoted the proliferation, migration and angiogenesis of high glucose-treated endothelial cells and reduced cell apoptosis. These effects were further enhanced by MSC-derived exosomes carrying circMYO9B overexpression. Mechanistically, circMYO9B promoted the translocation of hnRNPU from nucleus to cytoplasm and consequently destabilized CBL, thereby reducing the ubiquitination and degradation of KDM1A to promote VEGFA expression in endothelial cells. MSC-derived exosomes carrying circMYO9B promotes angiogenesis and thus accelerates diabetic wound healing through regulating the hnRNPU/CBL/KDM1A/VEGFA axis, indicating potential therapeutic targets and strategies for DFU treatment.