Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2020 Nov 5;14:594170. doi: 10.3389/fncel.2020.594170

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

Copyright © 2020 Zhang, Lei, Guo, Pei, Chen, Zhang, Cai, Mok, Lee, Swaminathan, Wang, Bai and Chen.

This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

PMC Copyright notice

Rescue of neuron:astrocyte ratio through NeuroD1-mediated in vivo AtN conversion. (A) Astrocytes are not depleted in NeuroD1-converted areas. Control AAV-infected injury areas showed intensive GFAP signals (green) with hypertrophic morphology (top row, 7 dpi). In contrast, NeuroD1-infected injury areas showed significantly reduced GFAP expression, and astrocytic morphology was less reactive (bottom row, arrowhead). Astrocytes (green) persisted in the NeuroD1-converted area (red). Scale bar = 200 μm (low mag, left), and 20 μm (high mag, right). Quantitative analysis revealed a significant reduction of both GFAP intensity and GFAP-covered area in NeuroD1-infected injury areas (right bar graphs). Note that the GFAP signal in the NeuroD1 group was reduced to half of the control group but still higher than non-injured brains, indicating that astrocytes were not depleted after NeuroD1 conversion. n = 4–6 mice per group. Each dot represents one animal. **P < 0.01, ***P < 0.001, two-way ANOVA followed by Bonferroni post hoc test. (B) Increased proliferation of astrocytes after NeuroD1-mediated cell conversion. BrdU was applied daily in GFAP::GFP mice between 7–14 dpi, a time window of cell conversion, to assess cell proliferation. We detected many proliferating astrocytes that were co-labeled with BrdU (magenta) and GFP (green) in the vicinity of NeuroD1-converted neurons (red). Scale bar = 20 μm. Quantitative analysis revealed a significant increase in the number of proliferating astrocytes (BrdU⁺/GFP⁺) in NeuroD1-infected injury areas, compared to the control group. n = 3 mice. *P < 0.05, Student’s t-test. (C) Representative images illustrating astrocytes (S100β, green; GFAP, cyan) and neurons (NeuN, red) in non-injured brains (NI), and stab-injured brains with mCherry control virus infection (mCH) or NeuroD1 virus infection (ND1). Scale bar = 100 μm. (D) Bar graphs illustrating quantitative analyses of the number of NeuN⁺ neurons, and GFAP⁺/S100b⁺ astrocytes among non-injured, mCherry control, and NeuroD1 groups (14 dpi). (E) Rescue of neuron:astrocyte ratio after NeuroD1-mediated AtN conversion. Quantitation of neuron:astrocyte ratio among non-injured, mCherry control, and NeuroD1 groups at 3, 7, and 14 dpi. The neuron:astrocyte ratio was 4:1 in non-injured mouse motor cortex, but significantly decreased to 0.6:1 after stab injury, and then reversed back to 2.6:1 by NeuroD1-mediated AtN conversion. n = 3–6 mice per group. *P < 0.05, ***P < 0.001, two-way ANOVA plus post hoc Sidak’s test.