Figure 1. IFNγ-promoted vascular endothelial growth factor (VEGF) expression of RPE cells. A: fRPE cells were seeded in a 96-well plate and treated with IFNγ, IL-6, TNFα, and TGFβ1 overnight. In each experiment, each treatment was performed in triplicate. After 24 h of culture, cells were collected and pooled for RNA purification. Real-time PCR assay was performed, and the results were expressed as the n-fold expression of hVEGF normalized on that of GAPDH or 18S rRNA. The asterisk indicates statistical significance (p<0.05) compared to the non-treated control group. B: ARPE-19 cells were cultured with IFNγ for 6 h and 24 h. Cells were collected, and the RNA was purified for real-time PCR assay. The results were expressed as the n-fold expression of hVEGF normalized on that of GAPDH or 18S rRNA. The values are expressed as the average+SEM of triplicates for each treatment. The results were representative data from two separate experiments. The asterisk and the double asterisk indicate statistical significance (p<0.05 and p<0.01, respectively) compared to the non-treated control group. C: ARPE-19 cells were cultured with 0, 0.1, 1.0, 10.0, and 25 ng/ml IFNγ, as well as 10 ng/ml IL-10, for 48 h. Cell supernatants were collected and used for ELISA analysis. The y-axis represents hVEGF concentration (pg/ml). D: ARPE-19 cells were cultured with or without 25 ng/ml IFNγ for 48 h. MTT assay was used to detect cell viability. E: ARPE-19 cells were treated with IL-6, IFNγ, TNFα, and a cocktail of these three cytokines for 48 h. Cell supernatants were collected and used for ELISA analysis. The y-axis represents hVEGF concentration (pg/ml). The double asterisk indicates statistical significance (p<0.01) compared to the control group.