Transcriptional regulation of neural stem cell expansion in the adult hippocampus

  1. Nannan Guo
  2. Kelsey D McDermott
  3. Yu-Tzu Shih
  4. Haley Zanga
  5. Debolina Ghosh
  6. Charlotte Herber
  7. William R Meara
  8. James Coleman
  9. Alexia Zagouras
  10. Lai Ping Wong
  11. Ruslan Sadreyev
  12. J Tiago Gonçalves
  13. Amar Sahay  Is a corresponding author
  1. Center for Regenerative Medicine, Massachusetts General Hospital, United States
  2. Harvard Stem Cell Institute, United States
  3. Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, United States
  4. BROAD Institute of Harvard and MIT, United States
  5. Ruth L. and David S. Gottesman Institute for Stem Cell Biology and Regenerative Medicine; Dominick Purpura Department of Neuroscience, Albert Einstein College of Medicine, United States
  6. Department of Molecular Biology, Massachusetts General Hospital, Harvard Medical School, United States
7 figures and 5 additional files

Figures

Figure 1 with 3 supplements
Klf9 is elevated in nondividing radial-glial neural stem cells (RGLs) and loss of Kruppel-like factor 9 (Klf9) promotes RGL activation.

(A, B) Klf9 expression inferred from LacZ expression intensity in quiescent RGLs, qRGL (GFP+ MCM2 with radial process, arrows), activated RGL, aRGL (GFP+ MCM2+ with radial process, arrowheads) and …

Figure 1—figure supplement 1
Generation and characterization of Kruppel-like factor 9 (Klf9) conditional mutant mouse line.

(A) Schematic of wild-type and modified Klf9 alleles. (B) PCR on tail DNA showing expected bands conveying wild-type and conditional alleles. (C) Left: Klf9 in situ hybridization on hippocampal …

Figure 1—figure supplement 2
Estimation of Kruppel-like factor 9 (Klf9) recombination frequency in Gli1-positive tdTomato-labeled radial-glial neural stem cells (RGLs).

(A) Representative low magnification images of Klf9 FISH signal (Klf9 transcripts) in dentate gyrus sections obtained from Gli1CreERT2:Klf9+/+:Ai14 and Gli1CreERT2:Klf9f/f:Ai14 mice following …

Figure 1—figure supplement 3
Inducible overexpression of Kruppel-like factor 9 (Klf9) in activated neural stem and progenitors promotes quiescence.

(A, B) Two cohorts of adult Sox1tTA: tetO Klf9 mice were used. Klf9 induction in neural stem and progenitors following 3 weeks off Dox significantly reduced the fraction of activated radial-glial …

Figure 2 with 9 supplements
Kruppel-like factor 9 (Klf9) deletion in radial-glial neural stem cells (RGLs) produces supernumerary RGL clones.

(A–D) Clonal analysis of sparsely labeled Gli1+ RGLs in adult Gli1CreERT2:Klf9+/+or f/f:Ai14 mice at 7 dpi. (A, C) Representative images of labeled RGL clones and descendants. For example, A top: …

Figure 2—figure supplement 1
Analysis of clonal composition in Figure 2C.

Representative images of labeled radial-glial neural stem cell (RGL) clones and descendants. Identification was based on tdTomato+ morphology and GFAP immunohistochemistry. Z-series of confocal …

Figure 2—video 1
Three-dimensional (3D) images of representative radial-glial neural stem cell (RGL) clonal compositions depicted in Figure 2C 1 RGL.
Figure 2—video 2
Three-dimensional (3D) images of representative radial-glial neural stem cell (RGL) clonal compositions depicted in Figure 2C 1 RGL.
Figure 2—video 3
Three-dimensional (3D) images of representative radial-glial neural stem cell (RGL) clonal compositions depicted in Figure 2C 1 RGL+ P + A.
Figure 2—video 4
Three-dimensional (3D) images of representative radial-glial neural stem cell (RGL) clonal compositions depicted in Figure 2C 1 RGL+ A.
Figure 2—video 5
Three-dimensional (3D) images of representative radial-glial neural stem cell (RGL) clonal compositions depicted in Figure 2C 1 RGL+ P.
Figure 2—video 6
Three-dimensional (3D) images of representative radial-glial neural stem cell (RGL) clonal compositions depicted in Figure 2C 2 RGLs.
Figure 2—video 7
Three-dimensional (3D) images of representative radial-glial neural stem cell (RGL) clonal compositions depicted in Figure 2C 2 RGLs+ P + A.
Figure 2—video 8
Three-dimensional (3D) images of representative radial-glial neural stem cell (RGL) clonal compositions depicted in Figure 2C 2 RGLs+ P.
Figure 3 with 5 supplements
Kruppel-like factor 9 (Klf9) functions as a brake on symmetric self-renewal of radial-glial neural stem cells (RGLs).

(A) Diagram of experimental design for in vivo two-photon imaging experiments. Inset is a high magnification image of a sparsely labeled single RGL in an adult Gli1CreERT2:Klf9+/+:Ai14 mouse. (B) …

Figure 3—figure supplement 1
Representative images of radial-glial neural stem cell (RGL) divisions captured using two-photon imaging in vivo.

(A) Representative two-photon images of RGL cells R1 and R2 in vivo and their respective post hoc fluorescence image. (B) Confocal immunofluorescence images of the same GFAP+/tdTomato+ cells at …

Figure 3—video 1
In vivo two-photon imaging of Gli1-postive radial-glial neural stem cells (RGLs).

Narrated example of longitudinal imaging of asymmetric neural stem cell (NSC) divisions. Two-photon imaging across days showing two examples of asymmetric division of NSCs (red arrows).

Figure 3—video 2
In vivo two-photon imaging of Gli1-postive radial-glial neural stem cells (RGLs).

Narrated example of longitudinal imaging of symmetric cell divisions. Two-photon imaging across days showing two examples of symmetric division of neural stem cells (NSCs; blue arrows).

Figure 3—video 3
In vivo two-photon imaging of Gli1-postive radial-glial neural stem cells (RGLs).

Three-dimensional reconstruction of RGL cells imaged in vivo before undergoing symmetric division. Field of view corresponds to second row of Figure 3B at 18 dpi.

Figure 3—video 4
In vivo two-photon imaging of Gli1-postive radial-glial neural stem cells (RGLs).

Three-dimensional reconstruction of RGL cells imaged in vivo after undergoing symmetric division. Field of view corresponds to second row of Figure 3B at 30 dpi.

Figure 4 with 1 supplement
Kruppel-like factor 9 (Klf9) regulates genetic programs underlying radial-glial neural stem cell (RGL) expansion.

(A) Schematic of experimental workflow to biochemically isolate and sequence translated mRNAs from Gli1+ RGLs (Gli1CreERT2:Rpl22HAf/+:Klf9f/f or +/+ mice). n = 3 mice, 6 dentate gyri/sample, 3 …

Figure 4—figure supplement 1
Annotation of upregulated and downregulated differentially expressed genes (DEGs) in Gli1+ radial-glial neural stem cells (RGLs) following Kruppel-like factor 9 (Klf9) deletion.

Gene ontology annotation (gGOSt, https://biit.cs.ut.ee/gprofiler/gost) of DEGs in Gli1+ RGLs following Klf9 deletion.

Summary schematic conveying Kruppel-like factor 9 (Klf9) functions in radial-glial neural stem cell (RGL) activation and self-renewal RGLs integrate extracellular, experiential signals to exit quiescence, the dominant state, and become activated.

Klf9 expression is elevated in quiescent RGLs. Low levels of Klf9 in RGLs are associated with increased activation. Once activated, RGLs lacking Klf9 are biased toward symmetric self-renewal and RGL …

Author response image 1
Inducible deletion of Klf9 in Ascl1+ RGLs in adult mice (Ascl1 CreERT2:Klf9+/+:Ai14 vs. Ascl1 CreERT2:Klf9f/f:Ai14) results in increased RGL activation (percentage of MCM2+tdTomato+Nestin+RGLs) n=4, 5 mice/group.

Data are represented as mean ± SEM. * p=0.02, Scale Bar 50 µm.

Author response image 2
A. Inducible deletion of Klf9 in Gli1+RGLs in adult mice (Gli1CreERT2:Klf9+/+:Ai14 vs. Gli1 CreERT2:Klf9f/f:Ai14) results in expansion of RGLs as assessed at 7dpi. Representative images (A-B) in and corresponding quantification (bottom) 7 dpi: n=4 and 5 mice/group. Data are represented as mean ± SEM. ** p<0.01. White arrowheads indicate RGLs. Note the dramatic expansion in RGL numbers throughout DG in B. Scale Bar is 20 µm.

Additional files

Supplementary file 1

Complete lists of differentially expressed genes (DEGs) in Gli1+ radial-glial neural stem cells (RGLs) following Kruppel-like factor 9 (Klf9) deletion.

DEGs were defined by at least 1.2-fold change with FDR < 0.05.

https://cdn.elifesciences.org/articles/72195/elife-72195-supp1-v2.xls
Supplementary file 2

Gene ontology annotation (gGOSt, https://biit.cs.ut.ee/gprofiler/gost) of differentially upregulated genes in Gli1+ radial-glial neural stem cells (RGLs) following Kruppel-like factor 9 (Klf9) deletion.

https://cdn.elifesciences.org/articles/72195/elife-72195-supp2-v2.xlsx
Supplementary file 3

Gene ontology annotation (gGOSt, https://biit.cs.ut.ee/gprofiler/gost) of differentially downregulated genes in Gli1+ radial-glial neural stem cells (RGLs) following Kruppel-like factor 9 (Klf9) deletion.

https://cdn.elifesciences.org/articles/72195/elife-72195-supp3-v2.xlsx
Supplementary file 4

Statistical Analysis.

https://cdn.elifesciences.org/articles/72195/elife-72195-supp4-v2.xlsx
Transparent reporting form
https://cdn.elifesciences.org/articles/72195/elife-72195-transrepform1-v2.pdf

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