Figure 4

Role of p38-MAPK and AP-1 in HIV-1 Vpr-mediated induction of CCL5 in astrocytes. SVGA astrocytes were pre-treated with the chemical inhibitors for the JNK-MAPK (SP600125) and p38-MAPK (SB203580) pathway 1 h before mock transfection or transfection with a plasmid encoding HIV-1 Vpr. (A) and (B) Effect of chemical inhibitors on mRNA expression and protein concentration for CCL5, respectively. SVGA cells were also transfected with siRNA targeting p38 isoforms (α, β, γ, δ) and AP-1 followed by mock transfection or transfection with a plasmid encoding Vpr. (C) and (F) Effect of siRNAs on CCL5 mRNA expression; (D) and (G) effect on CCL5 protein concentration, respectively. (E) Specificity of p38 isoform siRNAs against respective subunits; (H) inhibition of AP-1 (c-fos) with the siRNA directed toward the p38δ subunit of p38-MAPK. The bars represent the mean ± SE of three independent experiments done in triplicate. Statistical significance was determined using Student’s t-test, **p < 0.01, *p < 0.05.