HAEC were transfected with human IRF-1 siRNA (siIRF-1) (A-D) or pCMV6-XL5/human Irf-1 cDNA (E-H). Scrambled siRNA (siCtrl) and empty plasmid vector (sham) were used as controls. After 24 hr (knockdown) or 72 hr (overexpression), cells were stimulated with different doses of TNFα for 4 hrs prior to Western blot detection of IRF-1 (A, E), and flow cytometric analysis of VCAM-1 (B, F) and ICAM-1 (C, G) surface expression. Significance was determined by paired t-student test. (*P<0.05 vs. control. n=4). Flow cytometric analysis of VCAM-1 surface expression (D, H) Post-transfection, cells were treated with TNFα (0.3ng/mL) alone or plus TGRL (10mg/dl ApoB) for 4 hr (*P<0.05, **P<0.01 vs. siCtrl or sham; # P<0.05, ##P<0.01 pro- vs. anti-atherogenic TGRL group with the same transfection. NS, P>0.05. n=4–6).