Fig. 1.

KRT8 expression level is associated with autophagy progression in RPE cells under oxidative stress condition. A Confocal microscopic images in mCherry-EGFP-LC3B-expressing ARPE-19 cells. Cells were incubated in the absence or presence of paraquat for 24 h. Enlarged images of the white boxed areas are shown in the lower panels. Scale bar: 5 μm. Bar graph indicates the percentage of each fluorescence level in the merged images of mCherry-EGFP-LC3B under paraquat treatment conditions. Data are presented as the mean ± SEM, n = 3. **P < 0.01. B Confocal microscopic images of Lysotracker Red-stained and GFP-LC3B-transfected ARPE-19 cells under paraquat treatment for 24 h. Scale bar: 5 μm. Bar graph indicates the percentage of each fluorescence level in the merged images of GFP-LC3B and Lysotracker Red under the oxidative stress condition. Data are presented as the mean ± SEM, n = 3. **P < 0.01. C Immunoblots of KRT8, SQSTM1, and LC3B in ARPE-19 cells treated with paraquat for 24 h. Bar graphs indicate SQSTM1 expression level or the ratio of LC3B-II to LC3B-I (triplicate western blot images with ratios of LC3B-II/LC3B-I, shown in Fig. S1). Each protein band intensity was normalized to GAPDH. Data are presented as the mean ± SEM, n = 3. *P < 0.05