Endothelial cell elongation under shear stress : a computational model to consolidate observed cell shape changes

The endothelium, a single layer of cells that lines all blood vessels, is the principal sensor of hemodynamic wall shear stress (WSS). Changes in WSS are associated with diseases as inflammation, atherosclerotic plaque formation or aneurysms. It has long been established that endothelial cells are elongated under physiological blood flow conditions, but become cobblestone in culture under no flow conditions. To quantify this change of cell morphology, we measured the circularity and aspect ratio of porcine aortic endothelial cells cultured in physiological flux (30 dynes/cm2) or static condition. A parsimonious biomechanical cell-vertex model allows us for the first time to explain the observed changes in cell morphology by local changes in the cell boundary tension associated with changes in the architecture of the cytoskeletal network