FIGURE 5.

LPS induces nuclear protein binding to a NF-κB-binding element of the AhR promoter. Nuclear extracts from untreated control (lanes 1, 5, and 9) and LPS-treated (lanes 2, 6, and 10) U937-derived DC were used for EMSA. A, EMSA was performed using double-stranded, ³²P-labeled oligonucleotides containing the AhR-NF-κB1, AhR-NF-κB2, or AhR-NF-κB3 binding sequence of the human AhR promoter. A possible binding of RelA was identified by supershift analyses using RelA-specific antibodies (lanes 3, 7, and 11). B, EMSA was performed using double-stranded, ³²P-labeled oligonucleotides containing the AhR-NF-κB1 site. The bands corresponding to the specific LPS-induced RelA and p50 NF-κB subunits are indicated by arrows (lanes 3 and 4). To confirm specificity, a 100-fold excess of unlabeled AhR-NF-κB oligonucleotides from the AhR promoter was added (lane 5). One representative experiment of three independently performed experiments is shown. Ab., antibody; Comp., competition; Ctrl, control; Treat., treatment.