Fig. 6

GDF3 regulates neurogenesis and is reduced in AD brains. a To test whether GDF3 levels are also reduced in AD brains, Human AD and control cortical grey matter regions were lysed and the detergent soluble protein fraction was probed by western blot. Levels of active GDF3 (b) were quantified relative to neuron-specific enolase (NSE). c To identify areas in the brain where GDF3 may have a functional role, we referred to The Allen Brain Atlas, which showed strong RNA expression in the mouse hippocampus (blue = high expression). d Using qPCR, GDF3 mRNA expression was detected in non-differentiated adult mouse NPCs and NPCs cultured in differentiating conditions. e To determine whether GDF3 affects stem cell function, adult mouse NPCs were provided recombinant mouse GDF3 and NPC proliferation was assessed using BrdU. f Recombinant mouse GDF3 was also provided to dissociated adult mouse neurospheres and the number of newly formed neurospheres was subsequently quantified. g To investigate whether GDF3 promotes neurogenesis, human-derived NTERA cells stably transfected with Dcx promoter-controlled eGFP were provided recombinant human GDF3. Shown are representative images of DCX-GFP fluorescence expression from an entire well of NTERA cells treated with GDF3 or control for 30 days. h DCX-GFP fluorescence area was quantified relative to the cellular area detected by brightfield microscopy. Results were compared by a one-way ANOVA with a Dunnett's post-test (b,e), an unpaired Student’s t test (d), or a two-way ANOVA with a Bonferroni post-test (f,h) and are representative of at least 2 independent experiments (b n = 16 –18 per group, d,e,f,h; n = 3 per group). Values are mean ± s.e.m.. *p < 0.05, **p < 0.01, ***p < 0.001 compared to respective control groups