Fig. 7.

Mutant FUS iPSC-derived OPCs show enhanced ER stress after thapsigargin (TH) exposure. a–g Representative Western blots and quantification for BIP, CHOP, IRE1α, and ATF-4 levels in FUS^R521H and its isogenic control OPCs after 1 μM TH treatment for 24 h. All of the values are normalized to the control group (N ≥ 4 independent differentiations). h–n Representative Western blots of and quantification for BIP, CHOP, IRE1α, and ATF-4 levels in FUS^P525L and isogenic control OPCs after 1 μM TH treatment for 24 h (N ≥ 4 independent differentiations). o, q The mRNAs of spliced (sXBP1) and unspliced (uXBP1) were detected using RT-PCR in FUS^R521H and isogenic control OPCs (o) and FUS^P525L and isogenic control OPCs (q) after 2 μM TH treatment for 4 h. p, r Ratio of spliced to total XBP1 mRNA in FUS^R521H and isogenic control OPCs (N = 6) and FUS^P525L and isogenic control OPCs (N = 6). Statistical analyses were performed by one-way ANOVA with the Bonferroni’s multiple comparisons test (b–g and k–n) and unpaired two-tailed t test (p and r) to compare FUS-mutant OPCs and its control. Data are represented as mean ± SD. *p < 0.05 **p < 0.01 ***p < 0.001 ****p < 0.0001