Inhibition of plasminolytic activity at the cell surface of HMECs-1 by soluble p97 and mAb L235. (A) Effect of p97 on plasminolytic activity. HMECs-1 were treated for 18 hours with 100 nM p97 (+p97) or Ringer solution (Ctl). Following this treatment the plasminolytic activity was measured using standard conditions, as described in “Materials and methods.” (B) Effect of mAb L235 on plasminolytic activity of HMECs-1. HMECs-1 (1 × 105 cells) were preincubated for 1 hour at 37°C with Ringer solution (Ctl) or with 250 nM mAb L235 or nonspecific mouse IgG. Following this preincubation, the plasminolytic activity was measured for 6 hours by adding pro-uPA (1 nM) and plasminogen (50 nM) using standard conditions, as described in “Materials and methods.” The plasminolytic activity of HUVECs was also measured, using 1 × 105 cells under the same conditions. Data represent the means ± SDs of 3 independent experiments performed in triplicate. **P < .01, ***P < .001 (Student t test).
