Hdac3 Interaction with p300 Histone Acetyltransferase Regulates the Oligodendrocyte and Astrocyte Lineage Fate Switch (RNA-Seq)
ABSTRACT: 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. Gene expression profiling of optic nerve from P12 control and Hdac3 cKO mice
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:Tuberous sclerosis complex (TSC), an autosomal dominant disorder caused by mutations in either TSC1 or TSC2, exhibits white matter abnormalities including CNS myelin deficits. however, underlying mechanisms are not fully understood. Here we find that, unexpectedly, constitutive activation of mTOR signaling caused by Tsc1 deletion in the oligodendrocyte lineage results in severe myelination defects and oligodendrocyte cell death. Expression profiling analysis reveals that Tsc1 ablation induces prominent endoplasmic reticulum (ER) stress responses through the PERK‐eIF2α dependent signaling axis and activates Fas-JNK apoptotic pathways. Our studies suggest that TSC1-mTOR signaling acts as an important checkpoint for maintaining oligodendrocyte homeostasis. Gene expression profiling of optic nerve from P12 control and Tsc1cKO mice
Project description:Multiple sclerosis involves an aberrant autoimmune response and progressive failure of remyelination in the central nervous system. Prevention of neural degeneration and subsequent disability requires remyelination through the generation of new oligodendrocytes, but current treatments exclusively target the immune system. Oligodendrocyte progenitor cells are stem cells in the central nervous system and the principal source of myelinating oligodendrocytes. These cells are abundant in demyelinated regions of patients with multiple sclerosis, yet fail to differentiate, thereby representing a cellular target for pharmacological intervention. To discover therapeutic compounds for enhancing myelination from endogenous oligodendrocyte progenitor cells, we screened a library of bioactive small molecules on mouse pluripotent epiblast stem-cell-derived oligodendrocyte progenitor cells. Here we show seven drugs function at nanomolar doses selectively to enhance the generation of mature oligodendrocytes from progenitor cells in vitro. Two drugs, miconazole and clobetasol, are effective in promoting precocious myelination in organotypic cerebellar slice cultures, and in vivo in early postnatal mouse pups. Systemic delivery of each of the two drugs significantly increases the number of new oligodendrocytes and enhances remyelination in a lysolecithin-induced mouse model of focal demyelination. Administering each of the two drugs at the peak of disease in an experimental autoimmune encephalomyelitis mouse model of chronic progressive multiple sclerosis results in striking reversal of disease severity. Immune response assays show that miconazole functions directly as a remyelinating drug with no effect on the immune system, whereas clobetasol is a potent immunosuppressant as well as a remyelinating agent. Mechanistic studies show that miconazole and clobetasol function in oligodendrocyte progenitor cells through mitogen-activated protein kinase and glucocorticoid receptor signalling, respectively. Furthermore, both drugs enhance the generation of human oligodendrocytes from human oligodendrocyte progenitor cells in vitro. Collectively, our results provide a rationale for testing miconazole and clobetasol, or structurally modified derivatives, to enhance remyelination in patients. RNA sequencing of oligodendrocyte progenitor cells treated with vehicle, miconazole or clobetasol for 0, 2, 6, or 12 hours. Cells were plated 1.5 hours prior to addition of drug.
Project description:Expression profiling of distinct central nervous system (CNS) cell populations has been employed to facilitate disease classification and to provide insights into the molecular basis of brain pathology. One important cell type implicated in a wide variety of CNS disease states is the resident brain macrophage (microglia). In these studies, microglia are often isolated from dissociated brain tissue by flow sorting procedures [fluorescence-activated cell sorting (FACS)] or from postnatal glial cultures by mechanic isolation. Given the highly dynamic and state-dependent functions of these cells, the use of FACS or short-term culture methods may not accurately capture the biology of brain microglia. In the current study, we performed RNA-sequencing using Cx3cr1+/GFP labeled microglia isolated from the brainstem of 6-week-old mice to compare the transcriptomes of FACS-sorted versus laser capture microdissection (LCM). While both isolation techniques resulted in a large number of shared (common) transcripts, we identified transcripts unique to FACS-isolated and LCM-captured microglia. In particular, ∼50% of these LCM-isolated microglial transcripts represented genes typically associated with neurons and glia. While these transcripts clearly localized to microglia using complementary methods, they were not translated into protein. Following the induction of murine experimental autoimmune encephalomyelitis, increased oligodendrocyte and neuronal transcripts were detected in microglia, while only the myelin basic protein oligodendrocyte transcript was increased in microglia after traumatic brain injury. Collectively, these findings have implications for the design and interpretation of microglia transcriptome-based investigations. Wildtype and GFP expressing microglia from mouse brainstems were flow sorted or captured by laser microdissection. Differences between the two isolation methods were verified and further examined in neurodegenerative disease models.
Project description:This experiment compared the expression of mRNAs and noncoding RNAs during neuronal-glial fate specification and oligodendrocyte lineage maturation. The primary aim of the experiment was to identify ncRNAs that were differentially expressed during this process.
Project description:We performed gene expression profilings of platelet-derived growth factor subunit B (PDGFB)-induced mouse glioma to compare the differential transcriptome profiles between Ctrl-T tumor cells and Olig2cKO tumor cells. Expression profiling of Ctrl-T and Olig2cKO brain tumor (glioma) cells, normal oligodendrocyte progenitor cells (OPCs), normal astrocytes, and normal brain cortex by high-throughput sequencing.
Project description:The mechanisms underlying the specification of oligodendrocyte fate from multipotent neural progenitor cells (NPCs) in developing human brain are unknown. In this study, we sought to identify antigens sufficient to distinguish NPCs free from oligodendrocyte progenitor cells (OPCs). We investigated the potential overlap of NPC and OPC antigens using multicolor fluorescence-activated cell sorting (FACS) for CD133/PROM1, A2B5, and CD140a/PDGFaR antigens. Surprisingly, we found that CD133, but not A2B5, was capable of enriching for OLIG2 expression, Sox10 enhancer activity, and oligodendrocyte potential. As a subpopulation of CD133- positive cells expressed CD140a, we asked whether CD133 enriched bone fide NPCs regardless of CD140a expression. We found that CD133+CD140a- cells were highly enriched for neurosphere initiating cells and were multipotent. Importantly, when analyzed immediately following isolation, CD133+CD140a- NPCs lacked the capacity to generate oligodendrocytes. In contrast, CD133+CD140a+ cells were OLIG2-expressing OPCs capable of oligodendrocyte differentiation, but formed neurospheres with lower efficiency and were largely restricted to glial fate. Gene expression analysis further confirmed the stem cell nature of CD133+CD140a- cells. As human CD133+ cells comprised both NPCs and OPCs, CD133 expression alone cannot be considered a specific marker of the stem cell phenotype, but rather comprises a heterogeneous mix of glial restricted as well as multipotent neural precursors. In contrast, CD133/CD140a-based FACS permits the separation of defined progenitor populations and the study of neural stem and oligodendrocyte fate specification in the human brain. 12 samples, 4 groups (FACS-sorted cell populations),3 replicates in each group, each replicate is from a separate patient sample
Project description:Through single cell transcriptome analysis, we uncovered molecular signatures of CD133+/GFAP- ependymal (E) cells, CD133+/GFAP+ neural stem (B) cells, Dlx2+ neuroblasts (A cells), and Sox10+ oligodendrocyte progenitors (O cells) in the adult mouse forebrain neurogenic zone. prominent hub genes of the gene network unique to ependymal CD133+/GFAP- quiescent cells are enriched for receptors of angiogenic factors and immune-responsive genes. Administration of VEGF activated CD133+ ependymal stem cells lining not only the lateral, but also the 4th ventricles, and together with bFGF, elicited subsequent neural lineage differentiation and migration. Examination of 28 single cells and 4 populations of 10 cells from adult mouse forebrain neurogenic zone.
Project description:Mutations in CHD7, encoding ATP-dependent chromodomain-helicase-DNA-binding protein 7, in CHARGE syndrome leads to multiple congenital anomalies including growth retardation, craniofacial malformations and neurological dysfunction. Currently, mechanisms underlying the CNS phenotypes remain poorly understood. Here, we show that Chd7 is a direct transcriptional target of oligodendrogenesis-promoting factors Olig2 and Brg1 and required for proper timing of CNS myelination and remyelination. Genome-occupancy analyses coupled with transcriptome profiling reveal that Chd7 cooperates with Sox10 to target the enhancers of key myelinogenic genes, and identify novel Chd7 target. 4 RNA-Seq samples from P8 spinal cords of Ctrl and Chd7 cKO mice (duplicatess, Ctrl and cKO)