Sommaire:

The mechanical properties of epithelial tissues, which are typically composed of a single layer of tightly bound cells, play an important role in development and disease. Therefore, our goal is to develop theoretical and computational tools to help explain global mechanical behavior and cell migration patterns in these tissues. In this talk, I will focus on connections between tissue rigidity and collective migration using two different techniques in two different geometries. In the first project, we develop a hydrodynamic model for bulk tissues that couples cell shapes, tissue rigidity, and cell-substrate interactions by assuming that cells exert traction forces preferentially along gradients in the in-plane tissue stiffness, in accord with recent experiments. Analyzing the steady states of the model, we identify a new “morphotactic” parameter that our model predicts will control pattern formation in real tissues. In the second project, we developed a new active vertex model and employed it to simulate so called “wound-healing” experiments in which a tissue is allowed to expand into free space. These simulations indicate that tissues are unable to sustain a mechanical stress in the absence of propulsive forces generated by cell-substrate interaction. Further, our results suggest that polar order in these propulsive forces qualitatively changes the observed stress profile, and may thereby promote cell proliferation.

Pour plus d'informations, merci de contacter Berthier L.