Substrate Stiffness and Shear Stress Orchestrate Endothelial Inflammation and Remodelling via Mechanosensitive Pathways

Vascular ageing is a major contributor to cardiovascular disease and is closely linked to vascular stiffness. Stiffening of the vascular wall disrupts endothelial homeostasis and promotes chronic inflammation, yet the underlying mechanisms remain poorly understood due to technological limitations. Here, we developed an in vitro microfluidic model to investigate how biomechanical forces, specifically substrate stiffness and shear stress, interact to regulate endothelial cell behaviour. Using RNA sequencing and functional assays, we found that endothelial cells exposed to both physiological and high levels of shear stress were more sensitive to increases in substrate stiffness. Under these conditions, the cells exhibited a greater number of differentially expressed genes and enhanced activation of inflammatory signalling pathways, suggesting that mechanical stiffening promotes endothelial inflammation and contributes to vascular ageing.