Effect of Tat on the mRNA expression of tight junction proteins. D407 were treated in 100 nM HIV-1 Tat for 24 h with or without pretreatment with the NF-κB inhibitor PDTC (100 μM) and the ERK inhibitor PD98059 (30 μM) for 1.5 h. The relative expression level of each gene is expressed as fold induction compared with control group. Data are mean and S.D. Values shown represent the mean ± S.D. of three independent assays or experiments. The genes examined are shown on the horizontal-axis. (*P < 0.05, #
P < 0.01 vs. control; §
P < 0.05, Δ
P < 0.01 vs. HIV-1 Tat protein alone).