Cell stiffening in response to external stress is correlated to actin recruitment
Delphine Icard-Arcizet 1, Olivier Cardoso 1, Alain Richert 1 and Sylvie Hénon 1*
1 University Denis Diderot - Paris 7
* To whom correspondence should be addressed. E-mail: sylvie.henon{at}univ-paris-diderot.fr.
Submitted on July 26, 2007
Revised on September 2, 2007
Accepted on 30 November 2007
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Abstract |
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We designed a micromanipulation device that allows the local application of a constant force on living cells, and the measurement of their stiffness. The force is applied through a RGD-coated bead adhering on the cell and trapped in optical tweezers controlled by a feedback loop. Epifluorescence observations of GFP-actin in the cells are made during force application. We observe a stiffening of cells submitted to a constant force within a few minutes, coupled to actin recruitment both at the bead-cell contact and up to several µm from the stress application zone. Moreover, kinetics of stiffening and actin recruitment exhibit a strong correlation. This work presents the first quantification of the dynamics of cell mechanical reinforcement under stress, which is a novel insight into the elucidation of the more general phenomenon of cell adaptation to stress.
Key Words:
actin recruitment, cell mechanics, mechanotransduction, optical tweezers, stiffening
