DPSCs-generated contraction force regulates vessel network morphogenesis via YAP1/TGF-β1/Smad2 signaling

This study aimed to explore the contribution of dental pulp stem cell (DPSC)-generated contraction force to vessel formation and reveal the role of yes-associated protein 1 (YAP1) in DPSCs during this process.

The contraction force generated by DPSCs during vessel formation was evaluated in fluorescently labeled gels. DPSCs were treated with transforming growth factor beta 1 (TGF-β1), Cytochalasin D (CytoD), and Y27632 to investigate the correlation between F-actin-dependent contractility and YAP1. Furthermore, the involvement of YAP1 in DPSC differentiation into smooth muscle cells (SMCs) and the effect of YAP1-deficient DPSCs on impairing vascular morphology were assessed.

Enhanced matrix remodeling was observed during vessel formation, suggesting that DPSCs control vascular network formation via enhanced contraction force. DPSCs treated with Y27632 and CytoD showed reduced contractility, leading to decreased YAP1 nuclear translocation and changes in F-actin morphology. Western blot analysis showed that knocking down YAP1 in DPSCs significantly reduced phosphorylated Smad2, resulting in low expression of SMC markers. Furthermore, the loss of YAP1 in DPSCs weakened active cellular force, leading to deficient vessel network formation, including increased vessel diameter on day 4, reduction of vessel average length and loss of DPSC recruitment on day 7. In vivo results showed increased vessel diameter at day 7 and reduced human umbilical vein endothelial cell survival in the siYAP1-DPSC group.

YAP1 in DPSCs targets the TGF-β1/Smad2 pathway to mediate DPSC differentiation toward SMCs and to enhance contractile force, thereby controlling vessel network formation and maintenance.