Project description:While the core subunits of Polycomb group (PcG) complexes are well characterized, little is known about the dynamics of these protein complexes during cellular differentiation. We used quantitative interaction proteomics to study PcG proteins in mouse embryonic stem cells (mESCs) and neural progenitor cells (NPCs). We found the stoichiometry of PRC1 and PRC2 to be highly dynamic during neural differentiation.
Project description:Whole proteome profiling and quantification was performed on an isogenic Huntington disease (IsoHD) human embryonic stem cell (hESC) allelic panel. The IsoHD hESCs harbour 30, 45, 65 and 81 CAG repeats in the first exon of HTT. Whole proteome quantification was also performed on neural progenitor cells derived from the IsoHD hESC panel.
Project description:DNA methylation is known to regulate cell differentiation and neuronal function in vivo. Here we examined whether deficiency of a de novo DNA methyltransferase, Dnmt3a, affects in vitro differentiation of mouse embryonic stem cells (mESCs) to neuronal and glial cell lineages. We found that Dnmt3a-/- neural stem cells (NSCs) derived from mESCs have globally reduced methylcytosine levels and precociously differentiates into astrocytes and oligodendrocytes, consistent with our previous findings in the more severely hypomethylated Dnmt1-/- NSCs. Moreover, Dnmt3a-/- NSC proliferation rate was significantly increased when compared to control. Thus, our work revealed a novel role for Dnmt3a in regulating both timing of neural cell differentiation and cell proliferation in NSCs. Dnmt3a KO vs. WT neural stem cells; 3 biological replicates of each.
Project description:The Nucleosome Remodeling and Deacetylase (NuRD) complex plays an important role in gene expression regulation, stem cell self-renewal, and lineage commitment. Yet little is known about the dynamics of NuRD during cellular differentiation. Here, we study these dynamics using genome-wide profiling and quantitative interaction proteomics in mouse embryonic stem cells (ESCs) and neural progenitor cells (NPCs). The genomic targets of NuRD are highly dynamic during differentiation, with most binding occurring at cell-type specific promoters and enhancers. We identify ZFP296 as a novel, ESC-specific NuRD interactor that also interacts with the SIN3A complex. ChIP-sequencing in Zfp296 knockout (KO) ESCs reveals decreased NuRD binding both genome-wide and at ZFP296 binding sites, although this has little effect on the transcriptome. Nevertheless, Zfp296 KO ESCs exhibit delayed induction of lineage-specific markers upon differentiation to embryoid bodies. In summary, we identify an ESC-specific NuRD interacting protein which regulates genome-wide NuRD binding and cellular differentiation.
Project description:Comparison of genomic data from neural progenitor cells derived from mouse embryonic stem cells under different experimetnal conditions in vitro and invivo. We conducted genome-wide RNA sequencing of immunoprecipitated specific ribosome-associated mRNA using RiboTag methods from: (i) mouse embryonic stem cell (ESC), (ii) derived neural progenitor cells, (iii) differentiated neural progenitor cells (in vitro), (iv) grafted neural progenitor cells (recovered from different in vivo tissue enivornments - healthy spinal cord, spinal cord injury lesions) and (v) host astrocytes using GFAp-Cre RiboTag mice.
Project description:We report gene-expression profiling of different mouse embryonic stem cells (mESCs) mutant cell lines differentiating to neuronal lineages upon treatment with Retinoic Acid (RA) and Smoothened agonist (SAG). We generated genome-wide expression profiles of embryonic stem cells and neural progenitors at different differentiating time-points for different mutant cell lines and WT control mESCs. We find NKX2.2 and FOXA2 are key components of an intrinsic timer in neural stem cells founded on a negative feedback network that regulates the duration of motor neuron neurogenesis.
Project description:To identify genes that affect astrocyte differentiation from human embryonic stem cells, we have employed whole genome microarray expression profiling. We efficiently derived astrocytes through neural progenitor cells from human embryonic stem cells using our developed differentiation method. The cells on day 21 and 28 of astrocyte differentiation were compared with neural progenitor cells.
Project description:Fate and behaviour of neural progenitor cells is tightly regulated during mammalian brain development. Metabolic pathways, such as glycolysis and oxidative phosphorylation, that are required for supplying energy and providing molecular building blocks to generate cells, govern progenitor function. However, the role of de novo lipogenesis, which is the conversion of glucose into fatty acids through the multi-enzyme protein fatty acid synthase (FASN), for brain development remains unknown. Using Emx1Cre-mediated, tissue-specific deletion of Fasn in the mouse embryonic telencephalon, we show that loss of FASN causes severe microcephaly, largely due to altered polarity of apical, radial glia progenitors (APs) and reduced progenitor proliferation. Further, genetic deletion and pharmacological inhibition of FASN in human embryonic stem cell (ESC)-derived forebrain organoids identifies a conserved role of FASN-dependent lipogenesis for radial glia cell polarity and progenitor expansion in the developing human forebrain. Thus, our data establish a role of de novo lipogenesis for mouse and human brain development and identify a link between progenitor cell polarity and lipid metabolism.
