Abstract: Objective To investigate the effect of monocyte chemotactic protein-3 (MCP-3) on the expressions of intercellular
adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), tissue factor (TF, and tissue factor pathway
inhibitor (TFPI) and cell apoptosis in human umbilical vein endothelial cells (HUVECs). Methods Cultured HUVECs were
treated with MCP-3 at the optimal concentration determined previously 1 h after treatments with or without MCP-3 antibody
(20 ng/ml), PI3K inhibitor, or LY-294002 (5 mmol/ml). The expressions of ICAM-1, VCAM-1, TF and TFPI were analyzed using
RT-PCR and Western blot after the treatments. MCP-3 mRNA and protein expressions were detected in HUVECs exposed to
50 μg/ml ox-LDL for 24 h. The cell apoptosis and caspase-3 protein production in HUVECs treated with MCP-3 or with MCP-3
plus CCR2 antagonist for 24 h and 48 h were evaluated by flow cytometry and Western blotting. Results At the optimal
concentration of 0.3 ng/ml, MCP-3 treatment for 24 h caused significantly increased ICAM-1, VCAM-1, and TF expressions
with lowered expression of TFPI in HUVECs (P<0.05), and such effects were significantly inhibited by the application of
MCP-3 antibody, PI3K inhibitor, or LY-294002 (P<0.05). Ox-LDL exposure significantly increased the expression of MCP-3 in
HUVECs (P<0.05). HUVECs showed a significantly increased apoptosis rate after treatment with MCP-3 or with MCP-3 plus
CCR2 antagonist (P<0.05), and the apoptosis rate increased significantly as the treatment time prolonged (P<0.05); caspase-3
protein expression in the cells showed a similar pattern of alterations following the treatments. Conclusion ox-LDL can induce
MCP-3 expression in HUVECs. MCP-3 induces apoptosis of HUVECs and significantly affects the cellular function partially
through the PI3K signaling pathway.