Figure 7. Mitochondrial dynamics of HeLa cells with Drp1 wt and mutants treated with H₂O₂.

(A) HeLa cells were transfected with GFP-tagged Drp1wt or other mutants for 24 hours. Then cells were treated with 500 µM H₂O₂ for another 24 hours. Mitochondrial morphology of HeLa cells was observed by staining with Mitotracker under confocal microscopy. Cell nuclei were counter-stained by using DAPI. Insets are magnifications of the Mitotracker signal at the indicated areas. Inset 1 represents the non-transfected cells, and inset 2 indicates the transfected cells. Indications (white arrows) represent typical elongated mitochondria morphology. (B) Statistical results demonstrated mitochondrial morphology of HeLa cells with or without Drp1 expression under H₂O₂ treatment for 24 hours; over 100 transfected cells were categorized into 3 groups depending on mitochondrial morphology. **p<0.001.