Figure 3.

JAM-A Regulates Mechanical Stress on Tight Junctions and ECM

(A and B) FRET analysis by epifluorescence microscopy of MDCK cells transfected with siRNAs and ZO-1- or E-cadherin-based sensors. The quantification shows FRET efficiencies at cell-cell contacts (n for ZO-1-TS control siRNA, 31, and JAM-A siRNA, 37; ZO-1-TS-ΔCTD control siRNA, 17, and JAM-A siRNA, 20; E-cadherin-TS control siRNA, 34, and JAM-A siRNA, 31; and E-cadherin-TS-ΔCTD control siRNA, 19, and JAM-A siRNA, 19; ZO-1-TS and ZO-1-TS-ΔCTD control siRNA values are the same as those shown in Figure 1F, as the conditions were tested in parallel; box-plots show median and interquartile ranges).

(C–E) TFM on cells transfected with siRNAs as indicated and plated on PAA hydrogels. (C) shows images of the traction vector fields overlaid on phase contrast images and the corresponding stress maps on which the borders of the cell island is displayed. The quantifications in (D) and (E) show the derived strain energy density datapoints as the average value of all islands in single gels, and then show them normalized to respective controls to include 3 independent experiments (D) and absolute values of single islands of one representative experiment (medians with interquartile ranges are indicated; E). Magnification bars, 20 μm (A); 50 μm (C).