Objective：To investigate the effects of Dengue virus 2 (DV2) on the expression and secretion of vascular cell adhesion molecule-1 (VCAM-1)in human umbilical vein endothelial cells (HUVECs).Methods:HUVECs were primarily isolated,purified and cultured.Cells of 2-3 generations were infected with DV2 with different MOI values (1,2,4,8 and 16). HUVECs cultured with RPMI1640 medium were taken as negative control.The viability of HUVECs was assessed by CCK-8 assay before and at different time points after DV2 infection(6 h,12 h,24 h,48 h,72 h and 96 h).Flow cytometry was used to detect the VCAM-1 expression in HUVECs.The expression of cytoplasmic VCAM-1 mRNA was assayed by reverse transcription-polymerase chain reaction (RT-PCR).Results:When the MOI value was 2,DV2 had no significant influence on cell viability compared with the control group.DV2 infection significantly promoted the transcription of VCAM-1 mRNA compared with the control group(P<0.05).The expression of VCAM-1 mRNA peaked at 12 h after infection and remained at a higher level within 96 h(P<0.05).The expression at 12-48 h after infection was significantly higher than that at other time points(P<0.05).HUVECs hardly had VCAM-1 mRNA expression under normal condition. The expression of VCAM-1 protein was significantly increased at 12-72 h after infection compared with the control group(P<0.05).Conclusion:DV2 can increase the expression of VCAM-1 mRNA in HUVECs,which might be one of the important mechanisms for elevated vascular permeability and plasma leakage after DV2 infection.