Effect of APC on the LPS-mediated expression of cell adhesion molecules in HUVECs. Confluent HUVECs were incubated with LPS (100 ng/mL for 4 hours) after treating cells with indicated concentrations of APC for 3 hours. The cell surface expression of VCAM-1 (A), ICAM-1 (B), and E-selectin (C) on HUVECs was measured by a cell-based ELISA as described in “Methods.” All results are shown as means ± SDs of 2 different experiments with triplicate wells. *P < .05 and **P < .01 compared with LPS.