EGFL7 promotes weak adhesion of ECs. (A) ECIS was applied to monitor HUVEC adhesion to various substrates. The cells were seeded on gold electrodes coated with BSA, fibronectin, vitronectin, or EGFL7 and the resistance was monitored for at least 10 hours. (B) HUVECs were pretreated with α_vβ₃-blocking antibody LM609 and seeded on EGFL7-coated electrodes or BSA as a control (mean ± SEM, n = 4). (C) HUVECs were cultivated on glass coverslips coated with poly-L-lysine, EGFL7, or vitronectin and stained with anti-paxillin to visualize focal adhesions (arrows). Zoom of the area enclosed by the white rectangle is presented in the lower left corner of the picture. To detect stress fibers, cells were labeled with phalloidin. The bar represents 50 μm. (D) HUVECs were cultivated on plastic dishes coated with BSA, EGFL7, or vitronectin and total cell lysates (TCL) were blotted for the proteins indicated. Immunoprecipitations were performed using anti-FAK antibody and immune complexes were analyzed by western blotting using an anti-phosphotyrosine antibody. To analyze the activity status of Akt, a phosphoserine 473–specific antibody was used. Equal loading of respective proteins was verified by detection of FAK or Akt. (E) HUVECs were treated with specific α_vβ₃ inhibitor cRGDfV or control peptide cRADfV to block α_vβ₃ integrin-specific signaling effects.