Fig. 1: Overexpression of bHLH pioneer transcription factors upregulates Olig2 in astrocytes.
From: Olig2 acts as an inducible barrier to in vivo astrocyte-to-neuron conversion
a Experimental design for testing control and transcription factors (TFs) in adult mouse cortex. Created in BioRender.com. Hou, KY. (https://BioRender.com/b8j6fdr). b Confocal images displaying tdT co-staining with S100β, Sox10, Iba1 and NeuN (Nuclei: DAPI). Scale bar, 20 μm. c Quantified data indicating high astrocyte targeting rate by the AAV9 system; n = 5 mice per group, mean ± SD. d Olig2 staining in control vs TF groups; white dashed line indicates the AAV9 infection area. Scale bar, 100 μm. e Quantified data indicating a significant increase of Olig2 density with TF overexpression; n = 5 mice per group, one-way ANOVA followed by Bonferroni’s post hoc test, mean ± SD. f The schematic treatment of Sox10-CreERT2; Ai14 transgenic mice (Top). Created in BioRender.com. Hou, KY. (https://BioRender.com/0vi388m). Confocal images showing GFP, tdT, and Olig2 co-staining. Scale bars, left 50 μm, right 10 μm. g Quantification of Olig2+ cell density; n = 5 mice per group, unpaired two-sided Student’s t-test, mean ± SD. h The percentage of Olig2 distribution in tdT+ cells (Oligodendrocyte lineage cells) or GFP+ cells (AAV9-infected astrocytes) between the control and the Ngn2 group; n = 5 mice per group, unpaired two-sided Student’s t-test, mean ± SD. i Pie chart showing increased Olig2 in GFP+ astrocytes with Ngn2 overexpression. j Quantified data showing no significant change of tdT+ cell number between the two groups; n = 5 mice per group, unpaired two-sided Student’s t-test, mean ± SD. k Orthogonal images showing Olig2/GFAP co-expression (arrowhead). Olig2 presented only in Ngn2-transduced astrocytes (tdT+). Scale bars, 10 μm. l A significantly increased Olig2 expression in Ngn2-infected astrocytes labeled with different astrocytic markers; n = 5 mice per group, unpaired two-sided Student’s t-test, mean ± SD. m, Sustained Olig2 upregulation from 3 dpi to 60 dpi after AAV9-GFAP::Ngn2 injection. Arrowheads: Ngn2-infected astrocytes with Olig2 (tdT+), arrows: endogenous Olig2+ cells (tdT-). DAPI for nuclei. Scale bar, 20 μm. n Quantification of Olig2 expression in Ngn2-tdT+ cells over the different time points (gray dotted line showing expression level in the control group); n = 5 mice per group, mean ± SD.
