Fig. 4
AMD iPSC-RPE express lower SOD2 defense, lower mitochondrial activity and present higher cytoplasmic glycogen concentration. a AMD RPE-iPSC-RPE and AMD Skin-iPSC-RPE are not capable of increasing SOD2 expression under stress conditions as compared to normal RPE-iPSC-RPE. AMD and control iPSC-RPE were treated with 0.4 mM H2O2 for 2 h for 5 consecutive days after which RNA were extracted and analyzed via quantitative RT-PCR. As opposed to normal RPE-iPSC-RPE (6R, 10R, 25R), the AMD RPE-iPSC-RPE (9R, 32R) and AMD Skin-iPSC-RPE (005BF) were not responsive to stress conditions and did not increase the SOD2 gene expression under stress conditions. GAPDH was used to normalize the samples and the relative expression of each sample is compared. Asterisks (*) in a indicate statistical significance, determined by student t test (p ≤ 0.05). b, c AMD iPSC-RPE have significantly lower mitochondrial activity as compared to control iPSC-RPE, as indicated by ATP levels measured by a luminescence assay in the presence (b) and absence (c) of hexokinase inhibitor. Asterisks (***) in b and c show significance analyzed by Anova followed by Tukey, p ≤ 0.0001. d Measurement of cytoplasmic glycogen accumulation by colorimetric assay showing higher concentration in AMD iPSC-RPE as compared to control iPSC-RPE. Asterisks (****) in d show significance analyzed by Anova followed by Tukey, p ≤ 0.0001