Project description:This SuperSeries is composed of the following subset Series: GSE22473: Murine postnatal subventricular zone (SVZ) neural stem cells (NSCs): Wild-type (WT) vs. Dnmt3a-null (KO) GSE22474: Genome-wide location analysis of Dnmt3a-mediated epigenetic regulation in murine postnatal subventricular zone (SVZ) neural stem cells (NSCs) [Agilent] GSE22475: Genome-wide location analysis of Dnmt3a-mediated epigenetic regulation in murine postnatal subventricular zone (SVZ) neural stem cells (NSCs) [NimbleGen] Refer to individual Series
Project description:Transcriptional profiling of mouse postnatal SVZ NSCs comparing WT NSCs with KO NSCs under proliferating/undifferentiated states as well as differentiating conditions. Goal was to determine Dnmt3a-dependent gene expression changes in postnatal SVZ NSCs Two-condition experiment with a dye-swap design, WT NSCs vs. KO NSCs. Biological replicates: 4 replicates under proliferating/undifferentiation conditions, 2 replicates under differentiating conditions.
Project description:Throughout postnatal life in mammals, neural stem cells (NSCs) are located in the subventricular zone (SVZ) of the lateral ventricles. The greatest diversity of neuronal and glial lineages they generate occurs during early postnatal life in a region-specific manner. In order to evaluate potential heterogeneity in the NSC pool, we microdissected the dorsal and lateral SVZ at different postnatal ages and isolated NSCs and their immediate progeny based on their expression of Hes5-EGFP/Prominin1 and Ascl1-EGFP, respectively. Whole genome comparative transcriptome analysis revealed transcriptional regulators as major hallmarks that sustain postnatal SVZ regionalization. Manipulation of single genes encoding for locally enriched transcription factors influenced NSC specification indicating that the fate of regionalized postnatal SVZ NSCs can be readily modified . These findings reveal functional heterogeneity of NSCs in the postnatal SVZ and provide targets to recruit region-specific lineages in regenerative contexts. Microarrays of neural stem cells, early progenitors and the tissue from subregions of the subventricular zone were compiled to screen for the full extent of heterogeneity in this region during postnatal life. Spatially distinct regions of the developing forebrain subventricular zone (SVZ) aged at P4, P8 and P11 were microdissected in RNAse free/sterile conditions. Mice expressing Ascl1-EGFP in the SVZ were used to aid accurate microdissection of the dorsal and lateral wall of each of the studied time points as per our previous publications characterizing this method. As well as at the whole microdomain level, additionally, NSCs (Hes5-EGFP+/Prom1+) and early progenitors (Ascl1-EGFP+) from each microdomain were further isolated by FAC sorting methods. This was to provide a comprehensive gene expression analysis at the tissue level and at the cellular level. Generally, 1 litter was used to yield 1 'n' number of replicates. A total of 23 affymetrix analysis were performed.
Project description:Throughout postnatal life in mammals, neural stem cells (NSCs) are located in the subventricular zone (SVZ) of the lateral ventricles. The greatest diversity of neuronal and glial lineages they generate occurs during early postnatal life in a region-specific manner. In order to evaluate potential heterogeneity in the NSC pool, we microdissected the dorsal and lateral SVZ at different postnatal ages and isolated NSCs and their immediate progeny based on their expression of Hes5-EGFP/Prominin1 and Ascl1-EGFP, respectively. Whole genome comparative transcriptome analysis revealed transcriptional regulators as major hallmarks that sustain postnatal SVZ regionalization. Manipulation of single genes encoding for locally enriched transcription factors influenced NSC specification indicating that the fate of regionalized postnatal SVZ NSCs can be readily modified . These findings reveal functional heterogeneity of NSCs in the postnatal SVZ and provide targets to recruit region-specific lineages in regenerative contexts. Microarrays of neural stem cells, early progenitors and the tissue from subregions of the subventricular zone were compiled to screen for the full extent of heterogeneity in this region during postnatal life.
Project description:The epigenetic mechanisms that enable specialized astrocytes to retain neurogenic competence throughout adult life are still poorly understood. Here we show that astrocytes that serve as neural stem cells (NSCs) in the adult mouse subventricular zone (SVZ) express the histone methyltransferase EZH2. This Polycomb repressive factor is required for neurogenesis independent of its role in SVZ NSC proliferation, as Ink4a/Arf-deficiency in Ezh2-deleted SVZ NSCs rescues cell proliferation, but neurogenesis remains defective. Olig2 is a direct target of EZH2, and repression of this bHLH transcription factor is critical for neuronal differentiation. Furthermore, Ezh2 prevents the inappropriate activation of genes that specify non-SVZ neuronal subtypes. In the human brain, SVZ cells including local astroglia also express EZH2, correlating with postnatal neurogenesis. Thus, EZH2 is an epigenetic regulator that distinguishes neurogenic SVZ astrocytes, orchestrating distinct and separable aspects of adult stem cell biology, which has important implications for regenerative medicine and oncogenesis. Examination of histone modifications (H3K27me3 and H3K4me3) in subventricular zone neural stem cells
Project description:DNA methylation at proximal promoters facilitates lineage restriction by silencing cell-type specific genes. However, euchromatic DNA methylation frequently occurs in regions outside promoters. The functions of such non-proximal promoter DNA methylation are unclear. Here we show that the de novo DNA methyltransferase Dnmt3a is expressed in postnatal neural stem cells (NSCs) and is required for neurogenesis. Genome-wide analysis of postnatal NSCs indicates that Dnmt3a occupies and methylates intergenic regions and gene bodies flanking proximal promoters of a large cohort of transcriptionally permissive genes, many of which encode regulators of neurogenesis. Surprisingly, Dnmt3a-dependent non-proximal promoter methylation promotes expression of these neurogenic genes by functionally antagonizing Polycomb repression. Thus, non-promoter DNA methylation by Dnmt3a may be utilized for maintaining active chromatin states of genes critical for development. Chromatin extracted from wild-type (WT) or Dnmt3a-null (KO) SVZ NSCs was immunoprecipitated with indicated antibodies and analyzed by NimbleGen 2.1M mouse whole genome tiling microarrays (a 4-array set covering the entired non-repetitive portion of mouse genome). Whole cell extract (WCE) was used as input controls for IP/WCe experiments. For IP/IP experiments, immunoprecipitated DNA from WT and KO NSCs was directly compared on the same microarrays. For identifying Dnmt3a-dependent DNA methylation at a genome-wide scale, a dye-swap design was employed for comparing DNA methylation levels between WT and KO SVZ NSCs.
Project description:Previous work had established that Ezh2-deleted neural stem cells (NSCs) from the postnatal mouse subventricular zone (SVZ) had a deficit in both proliferation and neuronal differentiation both in vivo and in vitro. Ezh2-deleted NSCs in an Ink4a/Arf-deleted background proliferated normally but still displayed a neurogenesis defect, suggesting that Ezh2 is necessary for the proper expression of genes responsible for neuronal differentiation. Our results identify genes that are differentially regulated between control and Ezh2-deleted SVZ NSCs during differentiation. Total RNA obtained from SVZ NSCs 0, 1, 2, 4, and 7 days after switching from proliferation to differentiation media.
Project description:Transcriptional profiling of mouse postnatal SVZ NSCs comparing WT NSCs with KO NSCs under proliferating/undifferentiated states as well as differentiating conditions. Goal was to determine Dnmt3a-dependent gene expression changes in postnatal SVZ NSCs
Project description:Previous work had established that Ezh2-deleted neural stem cells (NSCs) from the postnatal mouse subventricular zone (SVZ) had a deficit in both proliferation and neuronal differentiation both in vivo and in vitro. Ezh2-deleted NSCs in an Ink4a/Arf-deleted background proliferated normally but still displayed a neurogenesis defect, suggesting that Ezh2 is necessary for the proper expression of genes responsible for neuronal differentiation. Our results identify genes that are differentially regulated between control and Ezh2-deleted SVZ NSCs during differentiation.
Project description:Distinct neural stem cells reside in different regions of the subventricular zone and generate multiple olfactory bulb interneuron subtypes in the adult mouse brain. This study shows that the basic helix-loop-helix type transcription factor Olig2 defines a ventrally enriched subset of NSCs in the early postnatal and adult SVZ and plays an important role in the subtype specification of olfactory bulb interneurons produced by adult NSCs.