YAP-mediated activation of VEGFA–VEGFR2 signaling in mechanically stimulated fibroblast exosomes enhances angiogenesis

Impaired angiogenesis hinders chronic wound healing. Exosomes derived from human dermal fibroblasts (HDF-exos) promote angiogenesis, but the underlying mechanism through which biomechanical cues shape their therapeutic potential remains unclear. Herein, we investigate the path following which the mechanical stimulation regulates the protein cargo of HDF-exos and their proangiogenic activity, with a focus on Yes-associated protein (YAP) and the VEGFA–VEGFR2 signaling pathway within a three-dimensional (3D), tissue-engineered dermis (TED) model. HDF-exos were isolated from fibroblasts cultured under static or mechanically loaded 3D TED conditions. Exosomal protein profiles were analyzed using proteomics, and their angiogenic effects on human umbilical vein endothelial cells (HUVECs) were evaluated by conducting proliferation, migration, and tube formation assays. Functional roles of BMP2, CXCL8, and the upstream regulator YAP were validated using neutralizing antibodies and pharmacological inhibition. Mechanical stimulation enriched HDF-exos with proteins linked to VEGFA–VEGFR2 signaling, including the marked upregulation of BMP2 and CXCL8. These exosomes considerably promoted HUVEC proliferation, migration, and tube formation, the effects attenuated by BMP2 or CXCL8 blockade. The inhibition of YAP suppressed BMP2 and CXCL8 expression in exosomes, confirming its role as a mechanosensitive regulator. Mechanical stress enhances the proangiogenic activity of fibroblast-derived exosomes through YAP-dependent enrichment of BMP2 and CXCL8, which are the key mediators of VEGFA–VEGFR2 signaling. These findings reveal a mechanotransduction–exosome–angiogenesis axis and highlight mechano-responsive exosomes as a promising therapeutic avenue for vascular regeneration in chronic wounds. • Mechanical stress enhances angiogenic protein cargo in fibroblast-derived exosomes. • HDF-exos promote endothelial proliferation, migration, and tube formation in vitro. • BMP2 and CXCL8 are key mediators in exosome-induced angiogenesis. • YAP inhibition reduces BMP2 and CXCL8 levels in mechanically stimulated exosomes. • VEGFA–VEGFR2 pathway links mechanotransduction to exosome-mediated angiogenesis.