Expression of VPO1 in response to ox-LDL in HUVECs and effect of knockdown of VPO1 by shRNA. (A, B, C and D) Ox-LDL up-regulated the expression of VPO1 (both mRNA and protein, analyzed by real-time PCR and Western blot, respectively) in a time- and concentration-dependent manner. (E) GFP immunofluorescence staining of the cells transfected with VPO1-shRNA. (F) VPO1-shRNA successfully decreased VPO1 protein expression. Data are expressed as means±SEM, n=6 each, performed in triplicate. Compared with control (0μg/ml ox-LDL) or 0 h, *P<0.05; **P<0.01.