Berlin 2015 – scientific programme
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BP: Fachverband Biologische Physik
BP 16: Posters: Cell adhesion, mechanics and migration
BP 16.20: Poster
Monday, March 16, 2015, 17:30–19:30, Poster A
Model-based traction force microscopy reveals differential tension in cellular actin bundles — •Christoph A Brand1,2, Jérôme RD Soiné1,2, Jonathan Stricker3, Patrick W Oakes3, Margaret L Gardel3, and Ulrich S Schwarz2 — 1These authors contributed equally — 2Institute for Theoretical Physics and BioQuant, Heidelberg University, Philosophenweg 19, 69120 Heidelberg, Germany — 3Institute for Biophysical Dynamics, Department of Physics, and The James Franck Institute, University of Chicago, Chicago, IL 60637, USA
Animal tissue cells continuously probe the mechanical properties of their environment, with dramatic consequences for cell adhesion, migration, differentiation and fate. Cellular forces originate mainly from the actomyosin system and are transmitted to the extracellular space via focal adhesions. A method called traction force microscopy has been developed to quantify these forces from the deformation of soft elastic substrates and to correlate them with observable structures of the cytoskeleton. For strongly adherent cells, major force generators are actin stress fibers, which have further been classified into different subtypes. However, the reconstruction of traction fields in this context is an ill-posed problem, which requires the use of regularization techniques. We present a new type of traction force microscopy that abolishes the need for regularization and allows us to directly estimate internal cell forces using a biophysical model for cell contractility. We use this method to demonstrate that ventral stress fibers are typically under higher tension than transverse arcs or dorsal stress fibers.