Fig. 7

UDCA inhibits GSK3β activity and rescues mutant TDP43-induced activation of GSK3β in cortical neurons. (a) ELISAs to demonstrate UDCA inhibition of GSK3β. Neurons were treated with 62.5 µM UDCA for 24 h and total and serine-9 phosphorylated GSK3β (p-GSK3β) levels quantified. Bar chart shows relative serine-9 phosphorylated/total GSK3β levels. Data were analysed by unpaired t-test. N = 5 independent experiments. Error bars are SEM, * p≤0.05. (b) Representative images of EGFP transfected neurons immunostained for serine-9 phosphorylated GSK3β (p-GSK3β) and MAP2 (artificially shown in cyan) to confirm neuronal identity. Scale bar = 5 μm. Bar charts show mean fluorescent intensity after normalisation to EGFP + vehicle treated control. Data were analysed by unpaired t-test. N = 40–42 cells from 5 independent experiments. Error bars are SEM, * p≤0.05. (c) Representative images of p-GSK3b immunostained neurons transfected with EGFP control, EGFP-TDP43-Q331K or EGFP-TDP43-A382T and treated with either vehicle or 62.5 µM UDCA for 24 h. TDP43 was identified via the EGFP tag and cells immunostained for MAP2 to confirm neuronal identity. Scale bars = 5 μm. Bar charts show mean fluorescent intensity after normalisation to EGFP + vehicle treated control. Data were analysed by one-way ANOVA with Tukey’s post hoc test. N = 24–30 cells from 3 independent experiments. Error bars are SEM; * p≤0.05, ** p≤0.01, *** p≤0.001, ns not significant