Protective Effect of Metformin against Hydrogen Peroxide-Induced Oxidative Damage in Human Retinal Pigment Epithelial (RPE) Cells by Enhancing Autophagy through Activation of AMPK Pathway

Figure 6

The activation of autophagy and the protective effect of metformin decreased after inhibition of the AMPK signaling pathway. D407 cells were pretreated with 2.5 μM compound C for 30 min before 1 mM metformin treatment for 2 h and then incubated with or without 200 μM H₂O₂ for further 24 h. (a) The expression of LC3B and p62 was assessed using ICC (scale bars, 50 μm). (b) The expression of LC3B, p62, P-Beclin1, and P-ULK1 was assessed by Western blot. (c) Cell viability was assessed using the MTT assay. (d) Cell cytotoxicity was measured by LDH assay. (e) Cells were pretreated with shAMPK plasmid, and after 48 h, cells were harvested and shAMPK interference efficiency was detected by Western blot. (f) Cells were pretreated with shAMPK3 plasmid and then treated as described above. Data are presented as the ; , .

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