Figure 8. Intracellular signaling involved in poly(I:C; 500 µg/ml)-induced gene expression in RPE cells. The cellular levels of the following gene transcripts were determined: TLR3 (A), bFGF (B), TNFα (C), IL-1β (D), and CFB (E) mRNAs. mRNA levels were determined with real-time RT–PCR analysis after stimulation of near-confluent cultures for 2 h (TNFα and IL-1β mRNAs) and 6 h (TLR3, bFGF, and CFB mRNAs), respectively, and are expressed as folds of unstimulated controls. The following blocking agents were tested: the inhibitor of ERK1/2 activation, PD98059 (20 µM); the inhibitor of p38 MAPK activation, SB203580 (10 µM); the JNK inhibitor SP600125 (10 µM); and the inhibitor of PI3K-related kinases, LY294002 (5 µM). Vehicle control was made with DMSO (DMSO; 1:1000). Each bar represents data obtained in 3 to 9 independent RPE cell lines, each from a different human eye donor; experiments with each cell line were carried out in triplicate. Significant difference versus unstimulated controls: *p<0.05. Significant difference versus poly(I:C) controls: ●p<0.05.