Modeling traction forces in collective cell migration

Collective cell migration is an important process in embryonic development, wound healing, and cancer metastasis. We have developed a particle-based simulation for collective cell migration that describes flow patterns and finger formation at the tissue edge observed in wound healing experiments [1]. We can apply methods for calculating intercellular stress to our simulation model, and have thereby provided evidence for the validity of a stress reconstitution method from traction forces used in experiments [2]. To accurately capture experimentally measured traction forces and stresses in the tissue, which are mostly tensile, we have to include intracellular acto-myosin contraction into our simulation. We can then reproduce the experimentally observed behavior of cells moving around a circular obstacle [3], and suggest underlying mechanisms for cell-cell alignment and generation of traction force patterns. [1] Basan, M., J. Elgeti, E. Hannezo, W.-J. Rappel, H. Levine. Proc. Natl. Acad. Sci. USA. 2013. [2] Zimmermann, J., R. L. Hayes, M. Basan, J. N. Onuchic, W.-J. Rappel, H. Levine. Biophys. J. 2014. [3] Kim, J. H., X. Serra-Picamal, D. T. Tambe, ..., J. J. Fredberg. Nature Mater. 2013.