Regensburg 2013 – scientific programme
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BP: Fachverband Biologische Physik
BP 32: Cell Adhesion and Mechanics
BP 32.6: Talk
Friday, March 15, 2013, 10:45–11:00, H43
Fluctuations of adhesion forces during cellular migration — •B. Sabass3, S. V. Plotnikov1, C. M. Waterman1, and U. S. Schwarz2 — 1Nat. Heart Lung and Blood Inst., NIH — 2Inst. f. Theo. Phys., U Heidelberg — 3-
Migration of endothelial cells is based on the concerted dynamics of intracellular structures
and adhesion sites. The continuous formation and dissociation of adhesion sites leads to observable
fluctuations of the transmitted force. In order to elucidate the connection between force
fluctuation and cellular migration we recently performed traction measurements for
integrin-based adhesions. The force fluctuation magnitude is seen to decrease monotonously for
increasing substrate stiffness. However, the speed of cellular migration shows a pronounced
maximum for intermediate stiffnesses around 8 kPa. The occurrence of stiffness-guided migration
(durotaxis) is promoted by the presence of force fluctuations.
Therefore, force fluctuations can be interpreted as dynamical sampling of extracellular stiffness to guide durotaxis.
We here suggest a quantitative interpretation of these results with a simple model for a cell-wide
force balance. The adhesion sites are described by a stochastic model that predicts a non-linear
relationship between extracellular rigidity and adhesion stability (1). The model is also employed
to compare measured effects of biochemical perturbations of the Paxillin module with predicted changes in the cellular mechanics.
(1) B. Sabass and U. S. Schwarz. J. Phys. Condensed Matter, 22, 2010.