YAP and ECM Stiffness: Key Drivers of Adipocyte Differentiation and Lipid Accumulation.

ECM stiffness significantly influences the differentiation of adipose-derived stem cells (ADSCs), with YAP-a key transcription factor in the Hippo signaling pathway-playing a pivotal role. This study investigates the effects of ECM stiffness on ADSC differentiation and its relationship with YAP signaling. Various hydrogel concentrations were employed to simulate different levels of ECM stiffness, and their impact on ADSC differentiation was assessed through material properties, adipocyte-specific gene expression, lipid droplet staining, YAP localization, and protein levels. Our results demonstrated that increasing hydrogel stiffness enhanced adipocyte differentiation in a gradient manner. Notably, inhibiting YAP signaling further increased lipid droplet accumulation, suggesting that ECM stiffness influences adipogenesis by modulating YAP signaling and its cytoplasmic phosphorylation. This study elucidates the molecular mechanisms underlying ECM stiffness-dependent lipid deposition, highlighting YAP's regulatory role in adipogenesis. These findings provide valuable insights into the regulation of cell differentiation and have important implications for tissue engineering and obesity treatment strategies.