Interaction of Shear Stress, Myosin II, and Actin in Dynamic Modulation of Endothelial Cell Microrheology

The endothelial cell (EC) cytoskeleton mediates several biological functions such as adhesion, migration, phagocytosis, cell division, and mechanosensitivity. These functions are carried out in part through dynamic cytoskeletal polymerization, modulation of crosslinking, and development of tension between intracellular organelles and the extracellular matrix via focal adhesion plaques. One important component of the cytoskeleton is actin which polymerizes into filaments and is thought to be prestressed by virtue of crosslinking proteins such as α-actinin, filamin and myosin II molecular motors. Additionally, actomyosin interaction has been hypothesized to act as a stress dissipation mechanism by virtue of dynamic crossbridging which facilitates actin diffusion through the polymer network of the cytoplasm (Humphrey et al., 2002).