Mechanical consequences of cellular force generation

The discovery that adherent tissue cells actively sustain internal tension and exert mechanical forces on their surroundings has opened new vistas in the field of cell and tissue mechanics. Cellular forces, generated by acto-myosin contractility, play a central role in numerous aspects of cell behavior and function. Apart from the various specific functions that cells perform by applying forces (e.g., wound healing, remodeling of the extracellular matrix and muscle contraction), cells also apply stresses as a generic means for sensing and responding to the mechanical nature of their environment. In addition, the internal tension plays a role in actively controlling the elastic moduli and shape stability of the cell. In this review, we survey recent theoretical and experimental studies of the physical consequences of cell mechanical activity including its role in cell morphology, adhesion strength, stress-fiber polarization, and the elastic properties of cells. We also discuss the role of cell mechanics in orienting cellular assemblies and in the response of cells to external loads.