  The mechanisms underlying collective migration, or the coordinated movement
of a population of cells, are not well understood despite its ubiquitous
nature. As a means to investigate collective migration, we consider a wound
healing scenario in which a population of cells fills in the empty space left
from a scratch wound. Here we present a simplified mathematical model that uses
reaction-diffusion equations to model collective migration during wound healing
with an emphasis on cell movement and its response to both cell signaling and
cell-cell adhesion. We use the model to investigate the effect of the MAPK
signaling cascade on cell-cell adhesion during wound healing after EGF
treatment. Our results suggest that activation of the MAPK signaling cascade
stimulates collective migration through increases in the pulling strength of
leader cells. We further use the model to suggest that treating a cell
population with EGF converts the time to wound closure (as function of wound
area) from parabolic to linear.
