Shear stress induces changes in the morphology and cytoskeleton organisation of arterial endothelial cells

The aim of this study was to determine the changes in the morphology and cytoskeleton organisation of endothelial cells (EC) determined by exposure to a laminar flow. Cultured EC were exposed to a wall shear stress of 6 dyne/cm 2 for 24 hours. The morphology of EC was analysed by light and scanning electron microscopy. The organisation of the cytoskeleton was determined by double fluorescence labeling with antibody anti-vimentin, anti-vinculin, anti-tubulin, and with rhodamine-labeled phalloidin. EC exposed to laminar flow become round-shaped with decreased area of adhesion to the substrate. There was a clear reorganisation of the cytoskeleton after exposure to shear stress; the distribution of actin changed from a stress fibre pattern to a more diffuse membrane-associated distribution. These changes in shape and cytoskeleton organisation were reversible after a 48-hour resting period. EC respond to laminar flow in a predictable manner and these findings may be correlated to the functional changes of EC observed after exposure to shear stress.