Figure 7. Involvement of heme oxygenase-1 (HO-1) in H₂O₂-induced apoptosis in retinal pigment epithelium (RPE) cells. Human RPE cells were transfected with control single interfering RNA (siRNA) or HO-1 siRNA. After being pretreated with 15 μM curcumin for 3 h, cells were treated with 1000 µM of H₂O₂ for 3 h. A: Transfection with siRNA against HO-1 caused reduction in HO-1 expression. The expression levels of HO-1 were determined by Western immunoblot analysis B: Apoptotic cells were detected with Annexin V-FITC staining and analyzed with flow cytometry. Histograms are representative of three independent experiments. Each bar represents mean±SD (standard deviation) from three independent experiments. *p<0.05.