Figure 9
Overexpression of the catalytic subunit of PP2A (PP2A-C) overcomes OA-mediated inhibition of basal PP2A phosphatase activity and significantly represses IL-6 and IL-8 mRNA expression and cytokine secretion.
A549 cells were transfected with empty vector or plasmid expressing PP2A-C, prior to 45 min with 1 μM OA, compared to vehicle. Cells were washed and then (A) PP2A-C overexpression confirmed by Western blotting (representative results are shown as cropped blots and full-length blots are presented in Supplementary Figure 3), (B) PP2A activity measured at 1 h, (C, D) IL-6 and IL-8 mRNA expression measured at 1 h (results expressed as fold increase compared to vehicle-treated cells) and (E, F) IL-6 and IL-8 protein secretion measured at 24 h. Statistical analysis was performed using one-way ANOVA then Bonferroni’s post-test (where * denotes a significant effect of OA or § PP2A-C) (P < 0.05)). Data are mean + SEM values from n = 3 independent experiments.
