Mapping cell-matrix stresses during stretch reveals inelastic reorganization of the cytoskeleton
Nuria Gavara 1, Pere Roca-Cusachs 1, Raimon Sunyer 1, Ramon Farre 1 and Daniel Navajas 1*
1 Facultat de Medicina - Universitat de Barcelona
* To whom correspondence should be addressed. E-mail: dnavajas{at}ub.edu.
Submitted on October 22, 2007
Revised on December 3, 2007
Accepted on 28 February 2008
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Abstract |
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The mechanical properties of the living cell are intimately related to cell signaling biology through cytoskeletal tension. The tension borne by the cytoskeleton (CSK) is in part generated internally by the actomyosin machinery and externally by stretch. Here we studied how cytoskeletal tension is modified during stretch and the tensional changes undergone by the sites of cell-matrix interaction. To this end we developed a novel technique to map cell-matrix stresses during application of stretch. We found that cell-matrix stresses increased with imposition of stretch but dropped below baseline levels upon stretch release. Inhibition of the actomyosin machinery resulted in a larger relative increase in CSK tension with stretch and in a smaller drop in tension after stretch release. Cell-matrix stress maps revealed that the loci of cell adhesion initially bearing greater stress also exhibited larger drops in traction forces after stretch removal. Our results suggest that stretch partially disrupts the actin-myosin apparatus and the cytoskeletal structures that support the largest CSK tension. These findings indicate that cells use the mechanical energy injected by stretch to rapidly reorganize their structure and redistribute tension.
Key Words:
cell contraction, cell mechanics, traction microscopy
