Project description:Establishment and maintenance of CNS glial cell identity ensures proper brain development and function, yet the epigenetic mechanisms underlying glial fate control remain poorly understood. Here we show that the histone deacetylase Hdac3 controls oligodendrocyte-specification gene Olig2 expression, and functions as a molecular switch for oligodendrocyte and astrocyte lineage determination. Our data suggest that Hdac3 cooperates with p300 to prime and maintain oligodendrogenic programs while inhibiting Stat3-mediated astrogliogenesis, and thereby regulate phenotypic commitment at the point of oligodendrocyte-astrocytic fate decision. Examination of Hdac3 and p300 genomewide occupancy in differentiating oligodendrocytes
Project description:We performed genome-wide profiling of Tcf7l2 occupancy during oligodendrocyte differentiation and identified the key enzymes involved in cholesterol metabolism and essential for CNS myelination. Examination of Tcf7l2 chIP-seq in oligodendrocyte progenitor cell and 2 differentiation oligodendrocytes.
Project description:We investigate the role of Brg1 and Olig2 during oligodendrocyte differentiation by combining gene conditional knockout and next generation sequencing technology. We generate genome-wide maps of RNA polymerase II (RPolII), Brg1 (Smarca4), Olig2 and histone modifications in primary rat oligodendrocyte precursor cells (iOLs), differentiating oligodendrocytes and mature oligodendrocytes.We found that Brg1 is intensely regulated by RPolII at the initiation of oligodedrocyte differentiation. The genomic distribution of Brg1 in differentiating oligodendrocytes is pre-directed by Olig2 in iOLs. The dynamic interaction of Brg1 and chromatin is correlate with the distinct stages of gene expression during maturation. Finally, we show that Brg1 and Olig2 localization predict critical genes controling CNS myeliantion. Our study represents the first detailed analysis of genomic landscape during the oligodendrocyte development and provides a framework for further understanding of molecular mechanisms underlying oligodendrocyte lineage progression. Genomic distribution of Brg1, Olig2, RPolII and three different histone modifications in three oligodendrocyte developemtal stages were examined using primary cells by ChIP-sequencing. Spinal cord mRNA profiles of 14-day old control and Brg1c/c;Olig1-Cre mice were generated by RNA-sequencing.
Project description:Myelination by oligodendrocytes in the central nervous system (CNS) is essential for proper brain function, yet the molecular determinants that control this process remain poorly understood. The basic helix-loop-helix transcription factors Olig1 and Olig2 promote myelination, whereas bone morphogenetic protein (BMP) and Wnt/β-catenin signaling inhibit myelination. Here we show that these opposing regulators of myelination are functionally linked by the Olig1/2 common target Smad-interacting protein-1 (Sip1). We demonstrate that Sip1 is an essential modulator of CNS myelination. Sip1 represses differentiation inhibitory signals by antagonizing BMP receptor-activated Smad activity while activating crucial oligodendrocyte-promoting factors. Importantly, a key Sip1-activated target, Smad7, is required for oligodendrocyte differentiation and partially rescues differentiation defects caused by Sip1 loss. Smad7 promotes myelination by blocking the BMP- and β-catenin-negative regulatory pathways. Thus, our findings reveal that Sip1-mediated antagonism of inhibitory signaling is critical for promoting CNS myelination and point to new mediators for myelin repair. ChIP-seq was performed to identify Olig2 direct target genes in oligodendrocytes during oligodendrocyte differentiation.
Project description:This SuperSeries is composed of the following subset Series: GSE40506: Genome-wide mapping of Olig2 targets in primary oligodendrocytes GSE40510: Expression data from Sip1 cKO and control mice spinal cord Refer to individual Series
Project description:Primary mixed glial cultures were prepared from dissociated cerebral cortices of Sprague-Dawley rats at postnatal day 1 to 3 and glial populations were isolated by sequential rotary shaking procedures using well-established protocols. Cultured cells were exposed to 1 micromol dexamethasone for 24hours prior to RNA isolation. Control samples were exposed to equal volume of carrier. For each cell type, RNA samples from four cultures were dispatched to Source Bioscience UK Ltd. (Nottingham) for processing and hybridisation. RNA integrity was determined using the Bioanalyzer (Agilent) and the three RNA samples with the highest quality per condition were selected for microarray analysis. 750ng of processed cRNA was hybridised to Illumina RatRef-12 bead chips.
Project description:We examine the role of Klf6 in oligodendrocyte progenitor cells and determine that Klf6 acts in part through direct regulation of gp130 signaling and nuclear import via importin-α5 (Impα5), a key controller of nuclear trafficking. Examination of Klf6 DNA binding in two different stages of differentiation