Zinc Protects Oxidative Stress-Induced RPE Death by Reducing Mitochondrial Damage and Preventing Lysosome Rupture

Figure 7

Cathepsin B staining indicating lysosomal rupture in zinc-depleted and oxidative-stressed RPE cells. RPE cells were treated with 5 M 4-HNE at 1.5 μM, 5 μM, and 15 μM zinc concentrations as well as an untreated control and 1.5 μM zinc only for 24 h before fixing the cells and immunostaining for cathepsin B. (a) Control RPE cells. (b) 1.5 μM zinc only. (c) 1.5 μM zinc + 4-HNE-treated RPE cells. (d) 5 μM zinc + 4-HNE-treated RPE cells. (e) 15 μM zinc + 4-HNE-treated RPE cells. Cell nuclei are stained with DAPI (blue) and cathepsin B (green). (f) Histogram showing the fluorescence intensity of cathepsin B staining in the different treatment groups, and , compared to the control. One-way ANOVA followed by Dunnett’s multiple comparison test. Fluorescence intensity of 30 cells per well was measured with three treatment replicate wells for each treatment.

(a)

(b)

(c)

(d)

(e)

(f)