Stretching and twisting

Cells exposed to repeated stretching along a unidirectional axis reinforce their actin stress fibers and reorient them to run perpendicular to the direction of strain. The two aspects of the response are regulated independently, report Yoshigi et al. (page 209).Numerous tissues are exposed to repeated mechanical strain and respond by reorganizing their cytoskeletons. Researchers hypothesize that stretch-responsive channels or cell adhesion sites may detect the mechanical force and control downstream changes.

When cells were exposed to mechanical stress, zyxin, a prominent component of focal adhesions, relocalized to actin stress fibers. Zyxin redistribution occurred only when cells were grown on a matrix that allowed integrin engagement, but blocking stretch-activated channels had no effect on zyxin mobilization. Zyxin movement also caused a similar relocalization from focal adhesions to stress fibers of vasodilator-stimulated protein...