Figure 7. Effects of viral RNA on the phosphorylation levels of ERK1/2, p38 MAPK, Akt, and STAT3 proteins in RPE cells. Near-confluent cultures were stimulated for 20 min and 1 h, respectively, with 100 and 500 µg/ml of poly(I:C). PDGF (10 ng/ml) was used as a positive control, and β-actin as a control for equal protein loading. Amounts of total proteins are shown above, while amounts of phosphorylated proteins are shown below. Similar results were obtained in three independent experiments using RPE cell lines from different human eye donors.