Effect of interleukin-8 (IL-8) or NADPH oxidase 1 (Nox1) knockdown on tissue factor (TF) expression in lipopolysaccharide (LPS) -stimulated human umbilical vein endothelial cells (HUVECs). (a, b) Effect of IL-8 knockdown on TF messenger (m) RNA expression in HUVECs 8 hr (a) or 12 hr (b) after LPS stimulation. The relative mRNA expression of TF was determined by real-time polymerase chain reaction (PCR). The expression level is shown relative to that in LPS-stimulated HUVECs treated with control small interfering (si) RNA. The data represent mean values ± SD (n = 4, **P < 0·01, Student's t-test). (c, d) Effect of Nox1 knockdown on TF mRNA expression in HUVECs 8 hr (c) or 12 hr (d) after LPS stimulation. The relative mRNA expression of TF was determined by real-time PCR. The expression level is shown relative to that in LPS-stimulated HUVECs treated with control siRNA. The data represent mean values ± SD (n = 4, **P < 0·01, Student's t-test). (e, f) Effect of IL-8 or Nox1 knockdown on TF protein expression in HUVECs 8 hr (e) or 12 hr (f) after LPS stimulation. The TF protein expression was determined by immunoblotting. Note that LPS-induced TF expression was markedly suppressed by IL-8 siRNA or Nox1 siRNA treatment at 12 hr.