Alignment of tractions between neighboring cells in a monolayer causes more persistent migration and faster wound closure

Following a wound, cell-generated forces elicit a migratory response as epithelial cells migrate collectively from the wound borders into the free space. The persistence of migration is a critical parameter in this phenomenon as cells must direct their migration towards the free edge. Migration persistence can be perturbed by physical and pharmacologic cues, such as wound geometry or heparin binding epidermal growth factor (HB-EGF), as both have a promigratory role in wound healing and strongly increase directional persistence. However, the role of cellular forces in altering the migration persistence is still unclear. To address this gap in understanding, we use both wound geometry and HB-EGF to systematically perturb the persistence of migration. Using single-cell velocity measurements and single-cell traction force microscopy, we compute the velocity and traction magnitudes, correlation lengths, and persistence times. We find a consistent trend caused by both wound geometry and HB-EGF wherein increased traction correlation length, but not traction magnitude or persistence, leads to more persistent migration. Hence, we conclude that increased traction correlation length, indicating increased coordination between neighbors, can increase the rate of wound closure.