Essential roles of the histone methyltransferase ESET in the epigenetic control of neural progenitor cells during development

Abstract

SUMMARYIn the developing brain, neural progenitor cells switch differentiation competency by changing gene expression profiles that are governed partly by epigenetic control, such as histone modification, although the precise mechanism is unknown. Here we found that ESET (Setdb1), a histone H3 Lys9 (H3K9) methyltransferase, is highly expressed at early stages of mouse brain development but downregulated over time, and that ablation of ESET leads to decreased H3K9 trimethylation and the misregulation of genes, resulting in severe brain defects and early lethality. In the mutant brain, endogenous retrotransposons were derepressed and nonneural gene expression was activated. Furthermore, early neurogenesis was severely impaired, whereas astrocyte formation was enhanced. We conclude that there is an epigenetic role of ESET in the temporal and tissue-specific gene expression that results in proper control of brain development. RESEARCH ARTICLE ESET in neural development MATERIALS AND METHODS Mouse linesESET flox (f) (Matsui et al., 2010), Emx2-Cre (Kimura et al., 2005) and Nes-Cre (Isaka et al., 1999) mice were described previously. Emx2-Cre;ESET(f/+) or Nes-Cre;ESET(f/+) male mice were crossed with ESET(f/f) female mice, and the day when a vaginal plug was observed was scored as embryonic day (E) 0.5. In situ hybridization, immunohistochemistry and antibodiesEmbryos were dissected, fixed in 4% paraformaldehyde (PFA)/PBS overnight and cryoprotected with 20% sucrose for at least 10 hours. On the following day, embryos were embedded in OCT compound (Tissue-Tek) and frozen at -80°C. Fixed samples were sectioned at 16 m with a cryostat and dried for 2 hours. In situ hybridization was then performed as previously described (Imayoshi et al., 2008). Primers used to produce in situ hybridization probes are listed in supplementary material Table S1. For immunohistochemistry, embryos at different ages were fixed in 4% PFA for 2 hours, equilibrated and sectioned as described above. Sections were blocked with 5% normal goat serum or donkey serum in 0.1% Triton X-100/PBS and incubated with primary antibodies at 4°C overnight. The following primary antibodies were used:

Oncogenic roles of the SETDB2 histone methyltransferase in gastric cancer

“…The H3K9 methyltransferase genes mediated global and promoter/enhancer region of H3K9 tri- di- and mono- methylation [29–32]. Knockdown of SETDB2 in MKN74 and MKN45 cells reduced global H3K9me3 (Figure 3A) but not H3K9me2 and H3K9me1 at the protein level, indicating that SETDB2 participates as an H3K9 tri-methyltransferase [10, 11].…”

PI3K/AKT/mTOR Signaling Mediates Valproic Acid-Induced Neuronal Differentiation of Neural Stem Cells through Epigenetic Modifications

“…The upregulation of H3K9 acetylation enhances neural differentiation and activates multiple neurodevelopmental genes (Qiao et al., 2015). However, decreased H3K9 trimethylation severely impairs early neurogenesis and enhances astrocyte formation (Tan et al., 2012). Pro-neural and terminal neuronal genes are poised in stem/progenitor cells by the balance between a repressor histone modification (H3K27me3) and an activator modification (H3K4me3) (McGann et al., 2014).…”

Chromosomal microarray analysis in clinical evaluation of neurodevelopmental disorders-reporting a novel deletion of SETDB1 and illustration of counseling challenge

“…On the other hand, deletion of SETDB1 , a histone methyltransferase, is particularly interesting. SETDB1 is a promising candidate gene for ASD/ID because of its role in epigenetic modification and brain function [26]. In mice, Setdb1 deficiency modifies the neuronal phenotypes caused by deficiency of the Rett syndrome protein MeCP 2 [27] and regulates the expression of NMDA receptor 2B[28], a gene implicated in cognitive function and epilepsy.…”