S. aureus up-regulates antimicrobial peptides (AMPs) expression in retinal Müller glia. MIO-M1 cells were infected with S. aureus (SA) for the indicated time points. Total RNA was extracted, reverse transcribed, and subjected to semi-quantitative RT-PCR using primers for specific AMPs and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) as the control (A). Real time PCR with a TaqMan® probe was used for the quantification of induced gene expression and the results were expressed as relative fold changes with respect to the GAPDH control (B). Statistical analysis was performed using one-way ANOVA (*P < 0.05; **P < 0.005), for comparisons of control versus stimulated cells over the time. Data points and bars represent mean ± SD of triplicates from three independent experiments.