Negative feedback from integrins to cadherins: a micromechanical study.

The coupling between cell-cell and cell-matrix adhesion systems is known to affect the stability of the adhesive status of cells, as well as tissue cohesion. In this work, we perform quantitative assays of integrin-cadherin cross talk in controlled and reproducible conditions. This is achieved by plating cells on microprinted fibronectin patterns of different sizes, and simulating the formation of an intercellular contact with a microbead coated with E-cadherin extracellular domains and brought to the cell membrane. Using an optical trap, we measure the average rigidity modulus of the E-cadherin bead-cell contact as a function of the contact incubation time and of the cell spreading area. For a given incubation time, this rigidity modulus decreases by three orders of magnitude as the cell-matrix contact area, A, increases from 100 to 700 μm(2). In a similar way, the dynamics of formation of the bead-cell contact gets slower as this area increases. This is clear evidence for a strong negative feedback from cell-fibronectin onto cell-cell adhesive contacts, for which we discuss some possible mechanisms.