Inhibition of gp120-induced IL-8 expression by gp120-specific siRNA. Four different siRNAs for gp120 were designed using the Ambion siRNA designing tool, and were commercially synthesized by Ambion Inc (A). 1 × 106 astrocytes were transfected with 50 nM of siRNA for 48 hours followed by gp120 transfection. mRNA (B) and protein (C) expressions of IL-8 were measured at 6 and 48 hours post gp120 transfection, respectively. mRNA expression is represented as fold change between gp120 transfected cells and cells transfected with empty plasmid. The protein expressions are presented as absolute concentrations (pg/ml). Each bar represents mean ± SE for 3 independent experiments with each experiment done in triplicate. Student's t test was used for statistical analysis and statistical significance is denoted as * (p value ≤ 0.05).