cellular response to external mechanical stimuli

mechanosensing & mechanotransduction

Magnetic tweezers can be used to investigate the ability of cells to respond to externally applied mechanical stimuli (mechanosensing). A magnetic bead coated with an ECM molecule is linked to  the integrin receptor in the cell (A).  The magnetic  bead is submitted to an oscillatory pulse regimen (B), and the oscillatory movement of the bead is monitored  over  time  (C). When cells with intact mechanosensing properties are submitted to a mechanical stimulus, they sense it, and stiffen the local area where the stimulus was applied. As a consequence of this, the amplitude of the oscillatory movement of the bead decreases over time. This can be observed in figure C, the amplitude of the oscillation decreased (first pulse back arrow, last pulse gray arrow). (D) Cells with affected mechanosensing can not decrease the amplitude of the bead oscillation, or decrease it to a smaller extend. (E) Relative stiffening expressed as a function of the ratio between the final and the initial oscillation of the bead.