Fibronectin‐dependent cell adhesion is required for shear‐dependent ERK activation

Abstract

Endothelial cells are subjected to hemodynamic shear stress, the dragging force generated by blood flow. Shear stress regulates endothelial cell shape, structure, and function, including gene expression. Since endothelial cells must be anchored to their extracellular matrices (ECM) for their survival and growth, we hypothesized that ECMs are crucial for shear‐dependent activation of extracellular signal‐activated regulated kinase (ERK) that is important for cell proliferation. Shear stress‐dependent activation of ERK was observed in cells plated on two different matrices, fibronectin and vitronectin (the two most physiologically relevant ECM in endothelial cells). We then treated bovine aortic endothelial cells (BAECs) with Arg‐Gly‐Asp (RGD) peptides that block the functional activation of integrin binding to fibronectin and vitronectin, and a nonfunctional peptide as a control. Treatment of cells with the RGD peptides, but not the control peptide, significantly inhibited ERK activity in a concentration‐d...