Effects of PPARα siRNA, COX inhibitors or antioxidants on DHA- or 4-HHE-induced HO-1 mRNA expression.

<p>(A) HUVECs were treated with PPARα siRNA or control siRNA, and incubated for 48 h. The relative mRNA expression of PPARα was quantitated using real-time RT-PCR. Each value represents the mean ± SE of three experiments. (B) HUVECs were transfected with siRNA targeted against PPARα or control siRNA. After 48 h, the cells were incubated with DHA (25 µM) for a further 6 h. The relative mRNA expression was analyzed quantitatively using real-time RT-PCR. Each value represents the mean ± SE of three experiments. (C–F) HUVECs were pretreated in the presence of indomethacin (10 µM), NS-398 (1 µM), SC-58125 (1 µM), BHT (100 µM), α-tocopherol (100 µM) or NAC (5 mM) for 1 h, and stimulated with DHA (25 µM) or 4-HHE (5 µM) for 6 h. The relative mRNA expression was quantitated using real-time RT-PCR. Each value represents the mean ± SE of 3–5 experiments. **<i>P</i><0.01, compared with the control cells treated with control siRNA, <b>^††</b><i>P</i><0.01, <b>^†††</b><i>P</i><0.001, compared with NAC-untreated corresponding cells.