TIMP-2 inhibits VEGF-A–induced endothelial cell permeability through PTP Shp-1 activity. (A) Quiescent hMVECs were pretreated with TIMP-2 (100nM) or Ala + TIMP-2 for 20 minutes and followed by VEGF-A (100 ng/mL) stimulation for 30 minutes. The results (mean ± SD) are expressed as the fold increase of FITC-dextran permeability in untreated control cells. **P < .01, compared with VEGF-A treatment alone. (B) Cells were pretreated with orthovanadate (2μM) for 20 minutes and followed by TIMP-2 or Ala + TIMP-2 before VEGF-A stimulation for 30 minutes. **P < .01, compared with VEGF-A treatment alone. (C) Cells transfected with control, Shp-1, or Shp-2 siRNA were treated as in panel A. **P < .01, compared with VEGF-A treatment alone. Cell lysates were Western blotted with anti-Shp-1, anti-Shp-2, or antiactin antibodies. Results are representative of 3 independent experiments.