Real-Time Monitoring of Cell Elasticity Reveals Oscillating Myosin Activity

The cytoskeleton is the physical and biochemical interface for a large variety of cellular processes Its complex regulation machinery is involved upstream and downstream in various signaling pathways The cytoskeleton determines the mechanical properties of a cell Thus cell elasticity could serve as a parameter reflecting the behavior of the system rather than reflecting the specific properties of isolated components In this study we used atomic force microscopy to perform real time monitoring of cell elasticity unveiling cytoskeletal dynamics of living bronchial epithelial cells In resting cells we found a periodic activity of the cytoskeleton Amplitude and frequency of this spontaneous oscillation were strongly affected by intracellular calcium Experiments reveal that basal cell elasticity and superimposed elasticity oscillations are caused by the collective action of myosin motor proteins We characterized the cell as a mechanically multilayered structure and followed cytoskeletal dynamics in the different layers with high time resolution In conclusion the collective activities of the myosin motor proteins define overall mechanical cell dynamics reflecting specific changes of the chemical and mechanical environment