Fig. 4

Generation and characterization of cortical-like neurons derived from MERRF-iPSCs undergoing neural-lineage differentiation. A Morphological change in the normal iNSCs at early stage of neuronal differentiation was observed at the indicated time points. B Morphological characterization of the iNSCs-derived neurons at day 14 of neuronal differentiation. Scale bars, 50 μm. C Phenotypic characterization of MERRF iNSCs-derived cortical-like neurons after 3 weeks of differentiation by the immunofluorescence staining with pan neuron markers, MAP2 (red), Tuj1 (green), and Hoechst 33342 (blue). Scale bars, 50 μm. D The protein expression levels of neuron-specific markers in normal and MERRF neurons after 3 weeks of differentiation. E Quantification of the proteins in Western blots was normalized with β-actin. All the data displayed as a fold change of normal neurons (N neurons). F Preservation of the heteroplasmy levels of the m.8344A > G mutation in MERRF neurons and the parental MERRF-iNSCs and MERRF-iPSCs. The proportion of mtDNA with the m.8344A > G mutation was quantified by PCR–RFLP. G The mutation level of m.8344A > G in MERRF neurons was confirmed by pyrosequencing. Data are presented as mean ± SEM, n = 3. *p < 0.05; **p < 0.01; ***p < 0.001