Monday  |  Salon 8  |  04:30 PM–04:50 PM

#15759, Characterization of Friction in Collective Cell Migration

Cells migrate collectively in cancer invasion, wound healing, and tissue formation. The migration results from forces produced by each cell, but because inertia is negligible, the active forces of the cells are balanced by an apparent viscous friction between neighboring cells and between the cell layer and the substrate beneath it. Hence, friction forms the essential link between force and motion, but the causes of friction and the associated magnitudes are not yet clear. Here, we study two experimental systems to characterize both the magnitudes and sources of friction. The first system draws on predictions of theoretical modeling, which predicts that the ratio of cell-cell viscosity to cell-substrate friction can be written as a length scale that is measurable in an in vitro wound healing experiment. The second cultures the cells in elongated islands wherein cell flow creates a local region of shearing. Using these two systems, in combination with traction force microscopy, monolayer stress microscopy, and fluorescent imaging of cell adhesions, we identify factors affecting the friction and propose new directions for quantifying friction in collective cell migration. We expect that our methods will inform models for collective migration and may motivate using friction to perturb the collective motion.

Molly McCord   University of Wisconsin-Madison
Kelly Vazquez   University of Wisconsin-Madison
Jacob Notbohm   University of Wisconsin-Madison