Propagation of mechanical stress through the actin cytoskeleton toward focal adhesions

• Verfasst von: Paul, Raja [VerfasserIn]
• Verfasst von: Heil, Patrick [VerfasserIn]
• Verfasst von: Spatz, Joachim P. [VerfasserIn]
• Verfasst von: Schwarz, Ulrich S. [VerfasserIn]
• Titel: Propagation of mechanical stress through the actin cytoskeleton toward focal adhesions
• Titelzusatz: model and experiment
• Verf.angabe: Raja Paul, Patrick Heil, Joachim P. Spatz, and Ulrich S. Schwarz
• Jahr: 2008
• Umfang: 13 S.
• Teil: volume:94
• Teil: year:2008
• Teil: number:4
• Teil: pages:1470-1482
• Teil: extent:13
• Fussnoten: Gesehen am 12.12.2017
• Titel Quelle: Enthalten in: Biophysical journal
• Ort Quelle: Cambridge, Mass. : Cell Press, 1960
• Jahr Quelle: 2008
• Band/Heft Quelle: 94(2008), 4, Seite 1470-1482
• ISSN Quelle: 1542-0086
• DOI: doi:10.1529/biophysj.107.108688
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1566260094

Abstract

We investigate both theoretically and experimentally how stress is propagated through the actin cytoskeleton of adherent cells and consequentially distributed at sites of focal adhesions (FAs). The actin cytoskeleton is modeled as a two-dimensional cable network with different lattice geometries. Both prestrain, resulting from actomyosin contractility, and central application of external force, lead to finite forces at the FAs that are largely independent of the lattice geometry, but strongly depend on the exact spatial distribution of the FAs. The simulation results compare favorably with experiments with adherent fibroblasts onto which lateral force is exerted using a microfabricated pillar. For elliptical cells, central application of external force along the long axis leads to two large stress regions located obliquely opposite to the pulling direction. For elliptical cells pulled along the short axis as well as for circular cells, there is only one region of large stress opposite to the direction of pull. If in the computer simulations FAs are allowed to rupture under force for elliptically elongated and circular cell shapes, then morphologies arise which are typical for migrating fibroblasts and keratocytes, respectively. The same effect can be obtained also by internally generated force, suggesting a mechanism by which cells can control their migration morphologies.