Skip to main content
. 2010 Apr 15;24(8):799–813. doi: 10.1101/gad.1880510

Figure 3.

Figure 3.

FOXO transcription factors promote axo–dendritic polarization in hippocampal neurons. (A–E) Hippocampal neurons were transfected with the control U6 or U6/foxo RNAi plasmid and the GFP expression plasmid. Four days after transfection, neurons were subjected to immunocytochemistry with the GFP antibody and Tau1 (B) or MAP2 (C) antibody. The percentage of neurons that failed to acquire a polarized morphology is quantified in A. Enrichment of Tau1 and MAP2 was quantified in D and E, respectively. A significant proportion of FOXO knockdown neurons failed to acquire a polarized morphology (P < 0.01; t-test, n = 3), and displayed significantly reduced Tau1 enrichment (P < 0.0001; t-test, 40 neurons measured) and significantly increased MAP2 enrichment (P < 0.0001; t-test, 57 neurons measured) when compared with control U6-transfected neurons. Arrowheads and arrows point to longest process and secondary processes, respectively. The asterisks indicate cell bodies. The double dagger points to the Tau1-positive axons of untransfected neurons. (F,G) Hippocampal neurons were transfected with the control U6 or U6/foxo RNAi plasmid together with the FOXO6-Res and GFP expression plasmids and were analyzed as in A. FOXO6-Res significantly reversed the FOXO RNAi-induced neuronal polarity phenotype (P < 0.05; ANOVA, n = 3). Arrowheads and arrows point to the longest process and other processes, respectively. (H–J) Hippocampal neurons were transfected as in F and, 4 d later, were analyzed as in B–E. Enrichment of Tau1 and MAP2 was quantified in H and I, respectively. A significant proportion of FOXO knockdown neurons failed to acquire a polarized morphology (P < 0.05; ANOVA, n = 3), and displayed significantly reduced Tau1 enrichment (P < 0.0001; ANOVA, 51 neurons measured) and significantly increased MAP2 enrichment (P < 0.0001; ANOVA, 57 neurons measured) compared with control U6-transfected neurons. These phenotypes were significantly reversed by FOXO6-Res (P < 0.0001; ANOVA, 51 neurons measured; Tau1 and P < 0.0001; ANOVA, 57 neurons measured; MAP2). Representative images of MAP2 immunostaining are shown in J.

HHS Vulnerability Disclosure