Fig. 4. Impaired mitochondrial dynamics and the impaired balance of mitochondrial fusion and fission in the APP-V715M iPSC-derived neurons. (A) Representative kymographs for mitochondrial movements. Cells were live stained using Mito-tracker at 10 weeks of neuronal differentiation. Average of anterograde (B) and retrograde (C) velocity were analyzed separately in motile mitochondria from iPSC-derived neurons. In both cases, significant decrease was observed in the APP-V715M iPSC-derived neurons compared with the control. (D) The Western blot images were from the representative results of three independent experiments. (E) Quantification of the protein levels associated with mitochondrial fusion (Mfn1and Mfn2) and fission (DRP1 and Fis1) at 6 and 10 weeks of neuronal differentiation. Note that fusion-related protein Mfn1 was decreased, whereas fission-related protein DRP1 was increased in the APP-V715M iPSC--derived neurons compared with the control. Data are presented as mean±SEM. Sample sizes: Fig. 4B and 4C (n=20); Fig. 4E (n=7). Two-tailed Student's t test was used for statistical analysis. ^***p<0.001.