Figure 3.

Pre-treatment with 10 µM PUN for 24 h modulates gene expression (A), protein synthesis (B), and nuclear activation (C) of Nrf2 in ARPE-19 cells exposed to UV-A radiation. (A) The levels of mRNA expression were measured by RT-PCR. Values are expressed as the mean percentage relative to unirradiated and not pre-treated cells (control 100%) ± SEM of four independent experiment performed in single. (B) Nrf2 protein levels were detected by colorimetric cell-based ELISA kit (see “Materials and Methods” section) and were expressed as the mean percentage relative to unirradiated and not pre-treated cells (control 100%) ± SEM of three independent experiment performed in triplicate. (C) To quantify Nrf2 activation in the nuclear extract, was utilized a colorimetric assay kit (see “Materials and Methods” section). All OD values were mathematically expressed as a percentage relative to unirradiated and not pre-treated cells (control 100%) ± SEM of three independent experiment performed in duplicate. Differences between mean values (shown in Figure 3) were assessed by one-way ANOVA analysis followed by post hoc Newman–Keuls. * = p < 0.05 and *** = p < 0.001 vs. control; °° = p < 0.01 and °°° = p < 0.001 vs. PUN alone; ^§§ = p < 0.01 and ^§§§ = p < 0.001 vs. UV-A alone at the same experimental time.