Fig. 6. Effect of siRNA targeting peripheral benzodiazepine receptor (PBR) on the action of midazolam to vascular cell adhesion molecule-1 (VCAM-1) expression in the human umbilical vein endothelial cells (HUVEC). (  A ) siRNAs targeting PBR decrease PBR proteins in the cultured HUVEC. Cells were transfected with 100 nM siRNAs targeting different coding regions of PBR or negative control siRNA and were analyzed 72 h later for PBR protein by Western blot analysis. siRNA#1, PBR 579 siRNA targeting human PBR exon; siRNA#2, PBR 564 siRNA targeting human PBR exon; siRNA #3, PBR 549 siRNA targeting human PBR exon; siRNA #4, PBR 788 siRNA targeting human PBR exon. Specific sequences of siRNA are described in Material and Methods. (  B ) Effect of PBR siRNA on inhibitory action of midazolam (5 μM) to TNF-α (15 ng/ml)–induced VCAM-1 expression. Used PBR siRNA #2 was PBR 564 siRNA targeting human PBR exon. Cells were transfected with 100 nM 564 PBR siRNAs or negative control siRNA and were then treated with TNF-α (15 ng/ml) in the presence or absence of midazolam (5 μM). Cells were analyzed 72 h later for PBR protein by Western blot. (  C ) Densitometric data. Expression levels are represented as percent densitometic value of VCAM-1 induced by TNF-α. Each bar shows mean ± SE (n = 3). *  P < 0.05 (negative siRNA  vs. PBR siRNA).