Figure 2

Activity of P2-COMT promoter is downregulated by TNFα in H4 astroglial cells. (A) Schematic diagram of human COMT gene. The exon-intron organization is not to scale. The positions of translation start codons for MB-COMT (MB-ATG) and S-COMT (S-ATG) polypeptides, translation stop codon (TGA), putative polyadenylation signal (AATTAA), promoter regions, and primers (U1 and D1) are shown. (B) Administration of TNFα (20 ng/ml) inhibits activity of transfected P2-COMT/Luc reporter in H4 but not in H4 IκBα-SR cells. Data are Means ± SEM. *P < 0.05, ***P < 0.001 H4 different from H4 IκBα-SR cells at 16 and 24 h, respectively. (C) TNFα-mediated inhibition is specific to P2-COMT promoter. The activity of 3x-κB/Luc reporter (κB consensus sites from the MHC class I promoter) was tested after treatment with TNFα (20 ng/ml) for 24 h. *P < 0.05 different from untreated control.