Effect of mechanical stretch and shortening on the stiffness of human aortic endothelial cells

External mechanical stimuli influence a broad range of biological phenomena-cell shape, motility, and adhesion, remodeling of the extracellular matrix, and the pathology of diseases such as arteriosclerosis and cancer. Changes in the cell cytoskeleton have been observed in response to mechanical stimuli-including single and cyclic stretch, as well as shortening. Changes in the cytoskeleton have also been shown to affect the cell's mechanical properties. Previous work has demonstrated that the cytoskeleton breaks down and reorganizes in response to mechanical stretch or shortening. Therefore, we expect the mechanical properties of the cell to be affected by stretch or shortening as well. We developed a unique device to stretch and shorten cells grown on compliant silicone membranes, while positioned on an Atomic Force Microscope (AFM) stage. After a single stretch or shortening of the membrane, we indent the cells in force-volume mode with the AFM, allowing us to measure the dynamic effect of these deformations on the mechanical properties of the cells.