Figure 7. H89 reduces DPR levels in C9 patient‐derived iPSC‐MNs.

• A, B
  Three independent C9 patient iPSC‐MN lines (Becker S6, M211R2, C90202) were treated with GELD, SPL, FSK, H89 or DMSO vehicle control and levels of poly‐GA (A) and poly‐GP (B) measured after 7 days. Values are displayed as percentages of mean DMSO signal. No significant changes in either DPR were observed (linear mixed effects model, all not significant, P > 0.05; P = 0.1 DMSO versus FSK). Treatments were performed in four technical replicates.
• C, D
  Three independent C9 patient iPSC‐MN lines were treated with 10 µM H89 and levels of poly‐GA (C) and poly‐GP (D) were measured after 14 days. Values are displayed as percentages of mean DMSO signal. H89 significantly reduced poly‐GA *P = 0.039 and poly‐GP levels *P = 0.018 (linear mixed effects model). Treatments were performed in four technical replicates.
• E
  No increased LDH release was observed after 14‐day 10 µM H89 treatment compared to vehicle treatment in two independent C9 patient iPSC‐MN lines (unpaired t‐tests, Becker S6: significant decrease in LDH, **P = 0.0064; M211R2: not significant, P > 0.05). In Becker S6, mean LDH release was 22% lower after H89 treatment compared to vehicle. Treatments were performed in eight technical replicates.
• F
  Relative fold changes of C9orf72 variant RNA levels normalized to RPL13A, after 14‐day 10 µM H89 treatment versus vehicle treatment (N = 1 C9 patient line, four technical replicates). No significant changes were observed between H89 and vehicle for any of the isoforms (2‐way ANOVA with Šídák's multiple comparisons test, all not significant, P > 0.05).

Data information: Error bars reported as ± SD. Not significant = P > 0.05, *P < 0.05, **P < 0.01.