Figure 6. Cytotoxicity of HRP‐dependent DAB polymerization occurring at the Golgi apparatus.

• A, B
  Two clones of U2OS cells that stably express HRP were stained for the GA marker GALT (A) showing extensive colocalization as determined by the Pearson correlation coefficient (B). Scale bar: 10 μm.
• C–E
  Cytotoxicity and DAB polymerization observed in U2OS‐GA‐HRP cells after treatment with DAB/H₂O₂ for 24 h at 37°C (C). Percentage of cells with DAB aggregates (D) and quantification of dead cells (PI⁺ cells) (E). DAB precipitates were observed by transmitted light microscopy, whereas cell viability was assessed by fluorescence microscopy upon double staining with PI and Hoechst. Scale bar: 20 μm.

Data information: Bars indicate means ± SD of triplicates of one representative experiment out of two repeats. Asterisks indicate significant differences with respect to untreated cells, whereas hashes indicate significant differences between WT cells and GA‐HRP clones, ***P < 0.001; ^### P < 0.001 (two‐way ANOVA).