HIV-1 Tat-mediated expression of IL-6 and IL-8 involves activator protein-1 (AP-1) transcription factor. (a-d) Astrocytes were transfected with either scrambled or C/EBPα or C/EBPγ or AP-1 siRNA for a duration of 48 hours, followed by either mock transfection or transfection with HIV-1 Tat plasmid. (a, b) The expression levels of IL-6 and IL-8 at mRNA were determined by real time RT-PCR at 6 hours post transfection. The values represented are normalized to their mock-transfected controls. (c, d) Multiplex cytokine assay was employed to measure the protein concentrations of IL-6 and IL-8 in the cell culture supernatants at 48 hours post transfection. Each experiment was done at least in triplicate and each bar represents the ± SE of three individual experiments. Statistical analyses was performed by one-way ANOVA and ** denotes P-value of ≤ 0.01.