Fig. 5: FTD3 patient-derived cortical neurons exhibit increased DNA damage and neurodegeneration, which are mitigated by p53 knockdown in both human neuron and Drosophila models.

Western blot analysis (a) and quantification of p-p53 (b) and γH2AX (c) proteins in 3-month-old iPSC-derived cortical neurons. Data are presented as mean ± SEM, n = 5 biologically independent differentiation experiments. Statistical significance was assessed by two-way ANOVA followed by Sidak’s multiple comparison test. Representative comet assay images (d) and quantification of relative tail length (e) in iPSC-derived 3-month-old neurons. Data are presented as mean ± SEM from the following numbers of randomly selected comets: Control (Subject 1): n = 53; CHMP2B^+/– (Subject 1): n = 55; Control (Subject 2): n = 64; CHMP2B^+/– (Subject 2): n = 62; CHMP2B^–/– (Subject 2): n = 53. Data were analyzed by two-way ANOVA followed by Sidak’s multiple comparison test. f Time-course analysis of neuronal viability using the LDH release assay in iPSC-derived neurons carrying the heterozygous FTD3-causing CHMP2B G26403C mutation, transduced with control shRNA (red), p53 shRNA-1 (magenta), or p53 shRNA-2 (grape). Data are presented as mean ± SEM, n = 6 biologically independent samples per group, generated from three independent differentiations of iPSCs derived from two subjects. Statistical significance was determined by one-way ANOVA followed by Tukey’s multiple comparison test. Western blot analysis (g) and quantification of CC3 (h) and SIRT1 (i) protein levels in 2-month-old cortical neurons after neurotrophic factor withdrawal. Data are presented as mean ± SEM, n = 4 biologically independent Western blot samples per group, obtained from two independent differentiations of isogenic iPSCs derived from two subjects. Statistical analysis was performed using two-way ANOVA followed by Sidak’s multiple comparison test. j Quantification of p53 mRNA levels in the head of CHMP2B^In5-expressing flies. Data are presented as mean ± SEM, n = 5 biologically independent experiments. Statistical significance was assessed by two-tailed Student’s t test. Representative images (k) and quantification (l) of retinal degeneration in Drosophila eyes expressing CHMP2B^In5 with control RNAi (against the mCherry gene) or p53 RNAi. The total number of flies of each genotype is indicated in each column. Statistical significance was assessed by chi-square test. Significance levels were defined as *P  <  0.05, **P  <  0.01, ***P  <  0.001, ****P  <  0.0001; ns not significant. The exact p values and all source data are provided as a Source Data file.