Figure 7.

Effect of caveolin-1 silencing on TNF–α- and linoleic acid (LA)-induced COX-2 expression and PGE₂ synthesis. Cells were transfected with siRNA for caveolin-1 (Cav-1 siRNA) or with scrambled control siRNA. Then, cells were treated with 0.5 ng/mL TNF-α alone for 24 hours, or pretreated with 20 μmol/L LA for 24 hours followed by exposure to TNF-α for additional 24 hours. Caveolin-1 protein levels were measured by Western blotting and normalized according to β-actin expression (Figure 7A). COX-2 protein levels were measured by Western blotting under the same experimental conditions as in Figure 7A (Figure 7B). Supernatants of cell cultures were collected and PGE₂ levels were measured by EIA (Figure 7C). Experiments were repeated three times and the blots shown are a representative of one of the experiments. Values are means ± SEM. Different letters represent significant difference among treatment groups.