title: Prediction of traction forces of motile cells.
abstract: When crawling on a flat substrate, living cells exert forces on it via adhesive contacts, enabling them to build up tension within their cytoskeleton and to change shape. The measurement of these forces has been made possible by traction force microscopy (TFM), a technique which has allowed us to obtain time-resolved traction force maps during cell migration. This cell 'footprint' is, however, not sufficient to understand the details of the mechanics of migration, that is how cytoskeletal elements (respectively, adhesion complexes) are put under tension and reinforce or deform (respectively, mature and/or unbind) as a result. In a recent paper, we have validated a rheological model of actomyosin linking tension, deformation and myosin activity. Here, we complement this model with tentative models of the mechanics of adhesion and explore how closely these models can predict the traction forces that we recover from experimental measurements during cell migration. The resulting mathematical problem is a PDE set on the experimentally observed domain, which we solve using a finite-element approach. The four parameters of the model can then be adjusted by comparison with experimental results on a single frame of an experiment, and then used to test the predictive power of the model for following frames and other experiments. It is found that the basic pattern of traction forces is robustly predicted by the model and fixed parameters as a function of current geometry only.
authors.affiliation: Laboratoire interdisciplinaire de physique (LIPHY), University Grenoble Alpes, 38000 Grenoble, France; Laboratoire interdisciplinaire de physique (LIPHY), CNRS, 38000 Grenoble, France.
authors.forename: Clément
authors.initials: C
authors.lastname: Roux
authors.affiliation: IAB, University Grenoble Alpes, 38000 Grenoble, France; IAB, INSERM, 38000 Grenoble, France.
authors.forename: Alain
authors.identifier: 0000-0002-2719-252X
authors.initials: A
authors.lastname: Duperray
authors.affiliation: Laboratoire interdisciplinaire de physique (LIPHY), University Grenoble Alpes, 38000 Grenoble, France; Laboratoire interdisciplinaire de physique (LIPHY), CNRS, 38000 Grenoble, France.
authors.forename: Valérie M
authors.initials: VM
authors.lastname: Laurent
authors.affiliation: Laboratoire interdisciplinaire de physique (LIPHY), University Grenoble Alpes, 38000 Grenoble, France; Laboratoire interdisciplinaire de physique (LIPHY), CNRS, 38000 Grenoble, France.
authors.forename: Richard
authors.initials: R
authors.lastname: Michel
authors.affiliation: Laboratoire interdisciplinaire de physique (LIPHY), University Grenoble Alpes, 38000 Grenoble, France; Laboratoire interdisciplinaire de physique (LIPHY), CNRS, 38000 Grenoble, France.
authors.forename: Valentina
authors.initials: V
authors.lastname: Peschetola
authors.affiliation: Laboratoire interdisciplinaire de physique (LIPHY), University Grenoble Alpes, 38000 Grenoble, France; Laboratoire interdisciplinaire de physique (LIPHY), CNRS, 38000 Grenoble, France.
authors.forename: Claude
authors.identifier: 0000-0003-3706-7148
authors.initials: C
authors.lastname: Verdier
authors.affiliation: Laboratoire interdisciplinaire de physique (LIPHY), University Grenoble Alpes, 38000 Grenoble, France; Laboratoire interdisciplinaire de physique (LIPHY), CNRS, 38000 Grenoble, France.
authors.forename: Jocelyn
authors.identifier: 0000-0002-1866-5604
authors.initials: J
authors.lastname: Étienne
keywords: cell adhesion; cell migration; cytoskeleton; emergent material; finite elements; modelling