Figure 7.
Measuring cellular forces with microposts and bowties. (A) Cells produce both forces with their extracellular environment (cell-matrix force) and forces with other cells (cell-cell force). (B) As indicated by the red arrows, the vector sum of cell-matrix forces exerted by a cell is zero. Fc (blue arrows) is the cell-cell force exerted by each cell. The cell-cell force is equal in magnitude but opposite in direction to the vector sum of a cell-matrix force. Cell A pulls on cell B with a cell-cell force equal and opposite to the force cell B exerts on cell A. Cells were constrained to a bowtie pattern by stamping fibronectin on the tips of select microposts. (C) Red arrows indicate cell-matrix forces. (D) Yellow arrows indicate cell-cell forces, i.e. tugging force. (E) A scatter plot showing adherens junction size vs. cell-cell (tugging) force under conditions that affect cytoskeletal tension. Adapted under the terms of PNAS License to Publish.[80] Copyright 2010, National Academy of Sciences.