Limits...
HDAC3 But not HDAC2 Mediates Visual Experience-Dependent Radial Glia Proliferation in the Developing Xenopus Tectum

View Article: PubMed Central - PubMed

ABSTRACT

Radial glial cells (RGs) are one of the important progenitor cells that can differentiate into neurons or glia to form functional neural circuits in the developing central nervous system (CNS). Histone deacetylases (HDACs) has been associated with visual activity dependent changes in BrdU-positive progenitor cells in the developing brain. We previously have shown that HDAC1 is involved in the experience-dependent proliferation of RGs. However, it is less clear whether two other members of class I HDACs, HDAC2 and HDAC3, are involved in the regulation of radial glia proliferation. Here, we reported that HDAC2 and HDAC3 expression were developmentally regulated in tectal cells, especially in the ventricular layer of the BLBP-positive RGs. Pharmacological blockade using an inhibitor of class I HDACs, MS-275, decreased the number of BrdU-positive dividing progenitor cells. Specific knockdown of HDAC3 but not HDAC2 decreased the number of BrdU- and BLBP-labeled cells, suggesting that the proliferation of radial glia was selectively mediated by HDAC3. Visual deprivation induced selective augmentation of histone H4 acetylation at lysine 16 in BLBP-positive cells. Furthermore, the visual deprivation-induced increase in BrdU-positive cells was partially blocked by HDAC3 downregulation but not by HDAC2 knockdown at stage 49 tadpoles. These data revealed a specific role of HDAC3 in experience-dependent radial glia proliferation during the development of Xenopus tectum.

No MeSH data available.


Related in: MedlinePlus

Visual deprivation-induced increase of proliferative cells is prevented by HDAC3 knockdown but not HDAC2 knockdown. (A) A cartoon showing that tadpoles at stage 46 were placed in a 12 h/12 h dark/light incubator for control, or a dark box for VD, or electroporated with HDAC2-MO/HDAC3-MO and placed in a dark box after 48 h for HDAC2-MO+VD/HDAC3-MO+VD. Tectal brains were labeled with BrdU at stage 49. (B) Representative fluorescent images showing BrdU- and BLBP-labeled cells in ctrl-MO (B1–B4), VD (B5–B8), HDAC2-MO (B9–B12), HDAC2-MO+VD (B13–B16), HDAC3-MO (B17–B20) and HDAC3-MO+VD (B21–B24) tadpoles. Scale: 50 μm. (C–D) Summary data showed that VD increased BrdU- and BLBP-labeled cells. HDAC3 but not HDAC2 knockdown partially blocked VD-induced increase of proliferative cells. (BrdU: Ctrl, 78.0 ± 8.3, N = 5, Ctrl-MO, 85.4 ± 7.1, N = 5, VD, 191.8 ± 16.4, N = 4, HDAC2-MO, 96.5 ± 8.5, N = 6, HDAC2-MO+VD, 168.2 ± 13.9, N = 4, HDAC3-MO, 54.2 ± 4.0, N = 4, HDAC3-MO+VD, 79.4 ± 4.1, N = 5; BLBP: Ctrl, 112.0 ± 5.6, N = 5, Ctrl-MO, 132.6 ± 9.7, N = 5, VD, 191.7 ± 9.9, N = 4, HDAC2-MO, 155.5 ± 7.8, N = 4, HDAC2-MO+VD, 211.5 ± 13.0, N = 5, HDAC3-MO, 86.0 ± 3.9, N = 4, HDAC3-MO+VD, 114.2 ± 6.0, N = 5; ***p < 0.001, **p < 0.01).
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC5037170&req=5

Figure 7: Visual deprivation-induced increase of proliferative cells is prevented by HDAC3 knockdown but not HDAC2 knockdown. (A) A cartoon showing that tadpoles at stage 46 were placed in a 12 h/12 h dark/light incubator for control, or a dark box for VD, or electroporated with HDAC2-MO/HDAC3-MO and placed in a dark box after 48 h for HDAC2-MO+VD/HDAC3-MO+VD. Tectal brains were labeled with BrdU at stage 49. (B) Representative fluorescent images showing BrdU- and BLBP-labeled cells in ctrl-MO (B1–B4), VD (B5–B8), HDAC2-MO (B9–B12), HDAC2-MO+VD (B13–B16), HDAC3-MO (B17–B20) and HDAC3-MO+VD (B21–B24) tadpoles. Scale: 50 μm. (C–D) Summary data showed that VD increased BrdU- and BLBP-labeled cells. HDAC3 but not HDAC2 knockdown partially blocked VD-induced increase of proliferative cells. (BrdU: Ctrl, 78.0 ± 8.3, N = 5, Ctrl-MO, 85.4 ± 7.1, N = 5, VD, 191.8 ± 16.4, N = 4, HDAC2-MO, 96.5 ± 8.5, N = 6, HDAC2-MO+VD, 168.2 ± 13.9, N = 4, HDAC3-MO, 54.2 ± 4.0, N = 4, HDAC3-MO+VD, 79.4 ± 4.1, N = 5; BLBP: Ctrl, 112.0 ± 5.6, N = 5, Ctrl-MO, 132.6 ± 9.7, N = 5, VD, 191.7 ± 9.9, N = 4, HDAC2-MO, 155.5 ± 7.8, N = 4, HDAC2-MO+VD, 211.5 ± 13.0, N = 5, HDAC3-MO, 86.0 ± 3.9, N = 4, HDAC3-MO+VD, 114.2 ± 6.0, N = 5; ***p < 0.001, **p < 0.01).

Mentions: Visual deprivation (VD) is known to increase the proliferation of radial glia in optic tectum (Sharma and Cline, 2010; Tao et al., 2015). For visual deprivation, we placed tadpoles at stage 48 in a dark box for 48 h. Control tadpoles transfected with Ctrl-MO at stage 46 were maintained under the normal 12 h light/dark cycle until for BrdU incorporation. Animals were incubated with BrdU for immunostaining of anti-BrdU and anti-BLBP at stage 49 (Figure 7A). The number of BrdU+ and BLBP+ cells in the control tectum was dramatically increased in VD tadpoles compared to control tadpoles (Figures 7B–D). To further test whether other HDACs are HDAC2 and HDAC3 play roles in the VD-dependent RGs proliferation, we transfected tectal brains with HDAC2-MO or HDAC3-MO at stage 46. Tadpoles were maintained in a 12 h/12 h dark/light box for 48 h and exposed to darkness for 48 h. We observed that VD-induced increase of BrdU+ or BLBP+ cells was notably decreased in HDAC3-MO transfected tadpoles compared to control or Ctrl-MO tadpoles (Figures 7B–D). However, tadpoles transfected with HDAC2-MO did not alter the numbers of BrdU labeling of progenitor cells or block VD-induced increase in BrdU+ cells (Figure 7C). The number of BrdU+ cells was significantly decreased in HDAC3-MO transfected tadpoles compared to Ctrl or Ctrl-MO tadpoles. We also found that the number of BrdU+ cells was dramatically decreased in VD exposed HDAC3-MO tadpoles compared to VD exposed tadpoles, suggesting that HDAC3 knockdown partially blocks VD-induced increase of BrdU+ cells. Taken together, HDAC3 knockdown decreases the number of BrdU+ and BLBP+ cells at stages 48 tadpoles. HDAC3 is involved in VD-induced increase of cell proliferation (Figures 7B–D). These data suggested that HDAC3 activity is required for RGs proliferation in the developing tectum.


HDAC3 But not HDAC2 Mediates Visual Experience-Dependent Radial Glia Proliferation in the Developing Xenopus Tectum
Visual deprivation-induced increase of proliferative cells is prevented by HDAC3 knockdown but not HDAC2 knockdown. (A) A cartoon showing that tadpoles at stage 46 were placed in a 12 h/12 h dark/light incubator for control, or a dark box for VD, or electroporated with HDAC2-MO/HDAC3-MO and placed in a dark box after 48 h for HDAC2-MO+VD/HDAC3-MO+VD. Tectal brains were labeled with BrdU at stage 49. (B) Representative fluorescent images showing BrdU- and BLBP-labeled cells in ctrl-MO (B1–B4), VD (B5–B8), HDAC2-MO (B9–B12), HDAC2-MO+VD (B13–B16), HDAC3-MO (B17–B20) and HDAC3-MO+VD (B21–B24) tadpoles. Scale: 50 μm. (C–D) Summary data showed that VD increased BrdU- and BLBP-labeled cells. HDAC3 but not HDAC2 knockdown partially blocked VD-induced increase of proliferative cells. (BrdU: Ctrl, 78.0 ± 8.3, N = 5, Ctrl-MO, 85.4 ± 7.1, N = 5, VD, 191.8 ± 16.4, N = 4, HDAC2-MO, 96.5 ± 8.5, N = 6, HDAC2-MO+VD, 168.2 ± 13.9, N = 4, HDAC3-MO, 54.2 ± 4.0, N = 4, HDAC3-MO+VD, 79.4 ± 4.1, N = 5; BLBP: Ctrl, 112.0 ± 5.6, N = 5, Ctrl-MO, 132.6 ± 9.7, N = 5, VD, 191.7 ± 9.9, N = 4, HDAC2-MO, 155.5 ± 7.8, N = 4, HDAC2-MO+VD, 211.5 ± 13.0, N = 5, HDAC3-MO, 86.0 ± 3.9, N = 4, HDAC3-MO+VD, 114.2 ± 6.0, N = 5; ***p < 0.001, **p < 0.01).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5037170&req=5

Figure 7: Visual deprivation-induced increase of proliferative cells is prevented by HDAC3 knockdown but not HDAC2 knockdown. (A) A cartoon showing that tadpoles at stage 46 were placed in a 12 h/12 h dark/light incubator for control, or a dark box for VD, or electroporated with HDAC2-MO/HDAC3-MO and placed in a dark box after 48 h for HDAC2-MO+VD/HDAC3-MO+VD. Tectal brains were labeled with BrdU at stage 49. (B) Representative fluorescent images showing BrdU- and BLBP-labeled cells in ctrl-MO (B1–B4), VD (B5–B8), HDAC2-MO (B9–B12), HDAC2-MO+VD (B13–B16), HDAC3-MO (B17–B20) and HDAC3-MO+VD (B21–B24) tadpoles. Scale: 50 μm. (C–D) Summary data showed that VD increased BrdU- and BLBP-labeled cells. HDAC3 but not HDAC2 knockdown partially blocked VD-induced increase of proliferative cells. (BrdU: Ctrl, 78.0 ± 8.3, N = 5, Ctrl-MO, 85.4 ± 7.1, N = 5, VD, 191.8 ± 16.4, N = 4, HDAC2-MO, 96.5 ± 8.5, N = 6, HDAC2-MO+VD, 168.2 ± 13.9, N = 4, HDAC3-MO, 54.2 ± 4.0, N = 4, HDAC3-MO+VD, 79.4 ± 4.1, N = 5; BLBP: Ctrl, 112.0 ± 5.6, N = 5, Ctrl-MO, 132.6 ± 9.7, N = 5, VD, 191.7 ± 9.9, N = 4, HDAC2-MO, 155.5 ± 7.8, N = 4, HDAC2-MO+VD, 211.5 ± 13.0, N = 5, HDAC3-MO, 86.0 ± 3.9, N = 4, HDAC3-MO+VD, 114.2 ± 6.0, N = 5; ***p < 0.001, **p < 0.01).
Mentions: Visual deprivation (VD) is known to increase the proliferation of radial glia in optic tectum (Sharma and Cline, 2010; Tao et al., 2015). For visual deprivation, we placed tadpoles at stage 48 in a dark box for 48 h. Control tadpoles transfected with Ctrl-MO at stage 46 were maintained under the normal 12 h light/dark cycle until for BrdU incorporation. Animals were incubated with BrdU for immunostaining of anti-BrdU and anti-BLBP at stage 49 (Figure 7A). The number of BrdU+ and BLBP+ cells in the control tectum was dramatically increased in VD tadpoles compared to control tadpoles (Figures 7B–D). To further test whether other HDACs are HDAC2 and HDAC3 play roles in the VD-dependent RGs proliferation, we transfected tectal brains with HDAC2-MO or HDAC3-MO at stage 46. Tadpoles were maintained in a 12 h/12 h dark/light box for 48 h and exposed to darkness for 48 h. We observed that VD-induced increase of BrdU+ or BLBP+ cells was notably decreased in HDAC3-MO transfected tadpoles compared to control or Ctrl-MO tadpoles (Figures 7B–D). However, tadpoles transfected with HDAC2-MO did not alter the numbers of BrdU labeling of progenitor cells or block VD-induced increase in BrdU+ cells (Figure 7C). The number of BrdU+ cells was significantly decreased in HDAC3-MO transfected tadpoles compared to Ctrl or Ctrl-MO tadpoles. We also found that the number of BrdU+ cells was dramatically decreased in VD exposed HDAC3-MO tadpoles compared to VD exposed tadpoles, suggesting that HDAC3 knockdown partially blocks VD-induced increase of BrdU+ cells. Taken together, HDAC3 knockdown decreases the number of BrdU+ and BLBP+ cells at stages 48 tadpoles. HDAC3 is involved in VD-induced increase of cell proliferation (Figures 7B–D). These data suggested that HDAC3 activity is required for RGs proliferation in the developing tectum.

View Article: PubMed Central - PubMed

ABSTRACT

Radial glial cells (RGs) are one of the important progenitor cells that can differentiate into neurons or glia to form functional neural circuits in the developing central nervous system (CNS). Histone deacetylases (HDACs) has been associated with visual activity dependent changes in BrdU-positive progenitor cells in the developing brain. We previously have shown that HDAC1 is involved in the experience-dependent proliferation of RGs. However, it is less clear whether two other members of class I HDACs, HDAC2 and HDAC3, are involved in the regulation of radial glia proliferation. Here, we reported that HDAC2 and HDAC3 expression were developmentally regulated in tectal cells, especially in the ventricular layer of the BLBP-positive RGs. Pharmacological blockade using an inhibitor of class I HDACs, MS-275, decreased the number of BrdU-positive dividing progenitor cells. Specific knockdown of HDAC3 but not HDAC2 decreased the number of BrdU- and BLBP-labeled cells, suggesting that the proliferation of radial glia was selectively mediated by HDAC3. Visual deprivation induced selective augmentation of histone H4 acetylation at lysine 16 in BLBP-positive cells. Furthermore, the visual deprivation-induced increase in BrdU-positive cells was partially blocked by HDAC3 downregulation but not by HDAC2 knockdown at stage 49 tadpoles. These data revealed a specific role of HDAC3 in experience-dependent radial glia proliferation during the development of Xenopus tectum.

No MeSH data available.


Related in: MedlinePlus