Figure 1. Regulation of the expression of the c-Fos and c-Jun genes in RPE cells. A: Presence of c-Fos and c-Jun gene transcripts in RPE cells. To confirm the correct lengths of the PCR products, agarose gel
electrophoresis was performed using products obtained from two RPE cell lines (1, 2) derived from different post-mortem donors.
Negative controls (0) were performed by adding double-distilled water instead of cDNA as template. The β-actin (ACTB) mRNA level was used to normalize the c-Fos and c-Jun mRNA levels. B–E: c-Fos and c-Jun mRNA levels, as determined with real-time reverse transcription (RT)–PCR analysis after stimulation of the
cells for 2, 6, and 24 h (as indicated by the panels of the bars). The mRNA levels are expressed as folds of the unstimulated
control. B: Effects of chemical hypoxia (induced with the addition of 150 µM CoCl2), culturing in a 0.2% O2 atmosphere, high (25 mM) glucose, extracellular hyperosmolarity induced with the addition of high (+ 100 mM) NaCl, and extracellular
hypo-osmolarity (60% osmolarity) on the expression levels of the c-Fos and c-Jun genes. C: Effect of the addition of 200 mM sucrose (in the absence and presence of 100 mM NaCl) on the expression of the c-Fos and
c-Jun genes. D: Dose-dependence of the effect of high extracellular NaCl on the c-Fos mRNA level. Ten to 100 mM NaCl were added to the culture
medium, as indicated in the bars. E: Effects of inflammatory and growth factors on the expression of the c-Fos gene. The following factors were tested: vascular
endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), heparin-binding epidermal growth factor-like growth
factor (HB-EGF), platelet-derived growth factor-BB (PDGF), transforming growth factor-β1 (TGF-β1), hepatocyte growth factor
(HGF), placental growth factor-2 (PlGF-2), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNFα). Each factor was applied
at 10 ng/ml. In addition, fetal calf serum (10%) was tested. Each bar represents data obtained in three to ten independent
experiments using cell lines from different donors. Significant difference versus unstimulated control: * p<0.05; ● p<0.05.