Pharmaceutical Induction of PGC-1α Promotes Retinal Pigment Epithelial Cell Metabolism and Protects against Oxidative Damage

Figure 3

ZLN005 protects ARPE-19 cells from prooxidant-induced cell death through the upregulation of PGC-1α. (a) Treatment with 10 μM ZLN005 increases mitochondrial antioxidant enzymes, TXN2 and SOD2. Expression of the cytoplasmic enzyme, SOD1, is also enhanced, while GPX1 is downregulated (veh, for all genes; ZLN, for all genes). (b) Accordingly, mitochondrial superoxide production is decreased after 24-hour treatment with ZLN005 (veh, for all genes; ZLN, for all genes). (c) 48 hours of exposure to 10 μM ZLN005 () does not increase LDH levels, measured as OD₄₉₀, compared to untreated cells (UNT, ) and vehicle only treatment (veh, ). Total kill (TK, ) of cells is achieved by treatment with 1x lysis buffer for 30 min. (d) Cell death induced by 18-hour exposure to 500 μM and 1000 μM H₂O₂ decreases significantly with pretreatment with 10 μM ZLN005 ( for all conditions). (e) ZLN005 protects cells from cytotoxicity mediated by 100 μg/ml ox-LDL ( for all conditions). (f) 24-hour pretreatment with 10 μM ZLN005 protects against NaIO₃-induced cell death in the differentiated ARPE-19. ZLN005 protection decreased LDH levels in prooxidant conditions below basal LDH levels when exposed to 2 and 2.5 mg/ml NaIO₃ (veh, ; ZLN, ). (g) Cells lacking PGC-1α (shPGC-1α, ) show a loss of the protective effect of 10 μM ZLN005 upon exposure to 1000 μM H₂O₂, while the effect is maintained in the associated control cells (shControl, ).

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