The effect of substrate stiffness on Notch signaling in endothelial cells

Endothelial cells that line the interior surface of blood vessels, are subjected to different environments with different mechanical properties (e.g. different organs, or healthy vs. tumor tissue). During angiogenesis, endothelial cells need to penetrate different tissues that present the cells with a variety of mechanical and chemical cues. However, it is unknown how endothelial cells respond differently to the different cues presented to them. One of the key factors regulating angiogenesis is Notch signaling. While Notch signaling is based on mechanotransduction activation mechanisms, it is unclear whether extracellular environments can regulate it. We therefore propose to examine how substrate stiffness affects Notch signaling in endothelial cells and during angiogenesis. To do that, we have developed an assay that uses artificial gels with different mechanical properties to test the effect of substrate stiffness on cell motility, and on the activity and cellular distribution of Notch receptors and ligands.