Stiffness-induced destabilization of adherens junctions inhibits vascular network formation by pulmonary endothelial cells in lung-derived extracellular matrix hydrogels

Extracellular matrix stiffness impacts vascular network formation (VNF), yet underlying molecular mechanosignaling pathways in lung-derived endothelial cells (HPMEC) interacting with lung-derived extracellular matrix (ECM) hydrogels are poorly understood. We show an inverse correlation between ECM stiffness and VNF. Using a novel ECM crosslinking platform to simulate up to stiffnesses of fibrotic lung ECM, we show that stiffness signals are received by FAs, leading to phosphorylation of focal adhesion kinase at Tyr397 (FAK-Y397). These signals are then conveyed through cell-cell adhesion junctions, modulating the integrity and expression of β-catenin at the membrane. As it appears, the mechanosignaling is independent of Wnt or YAP/TAZ pathways. Our findings underscore the role of mechanical signaling in vascular morphology and highlight the significance of cell contractility in this process. This organ-derived ECM model offers basic insights for fundamental research and potential translational applications in understanding vascular remodeling in fibrotic diseases.