Figure 4. Osmotic induction of inflammatory enzyme genes in RPE cells. A: Expression of COX (COX1, COX2) and PLA₂ genes (PLA2G1B, PLA2G2A, PLA2G4A, PLA2G5) in cultured RPE cells derived from two different donors (1, 2). To confirm the correct lengths of PCR products, agarose gel electrophoresis was performed using products obtained from two different donors (1, 2). Negative controls (0) were established by adding double-distilled water instead of cDNA as template. B: Effects of extracellular hyperosmolarity induced by addition of high (+100 mM) NaCl on the expression of COX and PLA₂ genes. The mRNA levels were determined with real-time reverse transcriptase (RT)-PCR analysis after stimulation of the cells for 2, 6, and 24 h, respectively, and are expressed as folds of unstimulated control. Means ± standard error of the mean (SEM) of 4–6 independent experiments using cell lines from different donors. Significant difference versus unstimulated control: *p<0.05.