Abstract
Cells in vivo encounter and exert forces as they interact with the extracellular matrix (ECM) and neighboring cells during migration. These mechanical forces play crucial roles in regulating cell migratory behaviors. Although a variety of studies have focused on describing single-cell or the collective cell migration behaviors, a fully mechanistic understanding of how the cell-cell (intercellular) and cell-ECM (extracellular) traction forces individually and cooperatively regulate single-cell migration and coordinate multicellular movement in a cellular monolayer is still lacking. Here, we developed an integrated experimental and analytical system to examine both the intercellular and extracellular traction forces acting on individual cells within an endothelial cell colony as well as their roles in guiding cell migratory behaviors (i.e., cell translation and rotation). Combined with force, multipole, and moment analysis, our results revealed that traction force dominates in regulating cell active translation, whereas intercellular force actively modulates cell rotation. Our findings advance the understanding of the intricacies of cell-cell and cell-ECM forces in regulating cellular migratory behaviors that occur during the monolayer development and may yield deeper insights into the single-cell dynamic behaviors during tissue development, embryogenesis, and wound healing.