Localization of PECAM-1 on HUVECs treated with iTCC.

HUVECs were grown to confluence on a glass coverslip and were incubated for 2 hours at 37°C with medium alone (A) or in the presence of either 200 U/mL TNF-α (B) or iTCC (5 nM) (C). Cells were then stained with anti–PECAM-1 (M89D3) mAb followed by FITC-GAM. Microscopic analysis was carried out in a Bio-Rad MRC 1000 confocal microscope (1 cm = 0.9 μm). Note the decrease of intercellular PECAM-1 staining in the TNF-α–treated HUVECs and the normal distribution of PECAM-1 in iTCC-treated HUVECs. Insets show fluorescence micrographs of F-actin distribution in HUVECs incubated with control medium (A), TNF-α (B), or iTCC (C).