Neuroprotective Effects of Idebenone on hydrogen peroxide (H2O2)-induced Oxidative Damage in Retinal ganglion cell-5 (RGC-5) Cells

Abstract Purposes To investigated the neuroprotective effect of Idebenone against H2O2-induced oxidative damage in RGC-5 cells. Methods RGC-5 cells were treated with different concentrations (5, 10, 20μM) of idebenone for 12h prior to addition of 300µM H2O2 for 12 h. The apoptosis of RGC-5 cells were detected by flow cytometry. The changes of mitochondrial membrane potential were detected by JC-1 staining. The autophagy in RGC-5 cells was observed by transmission electron microscopy, and the expression level of autophagy-related protein light chain3, Beclin-1 and mitochondrial membrane potential-related protein Cyt-c in RGC-5 cells were measured by Western blot analysis. Results Flow cytometry showed that the apoptosis rates in control group, H2O2 group and H2O2-treatment with Idebenone pretreatment groups were (6.48±0.55)%, (27.34±0.51)%, (22.88±0.52)%, (15.45±0.81)%, (12.59±0.58)%, respectively(F = 559.7, P <0.0001). After incubation with H2O2, the number of autophagosomes increased significantly, while which was decreased in H2O2-treatment with Idebenone pretreatment groups. After incubation of RGC-5 cells with H2O2, the mitochondrial membrane potential was significantly decreased, while idebenone could prevent the decrease of MMP. Contrast with control group, LC3 II /I, the expression levels of Beclin-1 and Cyt-c in H2O2 group increased significantly(P<0.05); while contrast with H2O2 group, LC3 II/I, the expression of Beclin-1 and Cyt-c in H2O2-treatment with Idebenone pretreatment groups was significantly decreased(P<0.05). Conclusion Idebenone may have protective effects on RGC-5 cells suffering from oxidative damage induced by H2O2 through improving antioxidant capacity, reducing mitochondrial membrane potential decline and the activity of autophagy.