Fig. 4

Metformin normalizes the proliferation status of FMRP-deficient NPCs but does not improve the neurite deficit in FMRP-deficient neurons. a Immunostaining shows proliferative markers BrdU (green) and Ki67 (red) expression. BrdU-labelling and Ki67 reveal increased proliferation in FMR1KO compared to control in the vehicle-treated condition. Treatment with a range of doses of metformin (0.25, 0.5 and 1 mM) ameliorates the excessive proliferation rate in the FMR1KO NPCs. Scale bar = 50 μm. b Quantification of BrdU- and Ki67-positive cells by ImageJ. Values shown as mean ± SEM based on blinded counting of 10 images per genotype per treatment condition. Statistical significance was determined by one-way ANOVA with Fisher’s LSD post hoc test; *p < 0.05, **p < 0.01 and ***p < 0.001; number sign (#) for comparison to control-vehicle and dollar sign ($) for comparison to KO-vehicle. c Neurite outgrowth and branching measurements for neurons treated with 0.5 or 1 mM metformin over the course of 7 days. Values shown as mean ± SD from 4 independent wells of 9 image fields per genotype