ABSTRACT: Comprehensive Identification of Long Non-coding RNAs in Purified Cell Types from the Brain Reveals Functional LncRNA in OPC Fate Determination (OLIG2 Chromatin immunoprecipitation sequencing (ChIP-Seq) in mouse neural stem cells)
Project description:Comprehensive Identification of Long Non-coding RNAs in Purified Cell Types from the Brain Reveals Functional LncRNA in OPC Fate Determination
Project description:Comprehensive Identification of Long Non-coding RNAs in Purified Cell Types from the Brain Reveals Functional LncRNA in OPC Fate Determination (RNA-Seq of differentiated NSC after lnc-OPC knockdown)
Project description:Comprehensive Identification of Long Non-coding RNAs in Purified Cell Types from the Brain Reveals Functional LncRNA in OPC Fate Determination (RNA-Seq of mouse neural stem cells)
Project description:We performed an integrated study of genome-wide OLIG2 binding and the epigenetic modification status of both coding and non-coding genes during three stages of oligodendrocyte differentiation in vivo: Neural Stem Cells (NSC), Oligodendrocyte Progenitor Cells (OPC), and Newly Formed Oligodendrocytes (NFO). We found that 613 lncRNAs have OLIG2-binding sites and are expressed in at least one cell type, which can potentially be activated or repressed by OLIG2. 48 of them have increased expression in oligodendrocyte lineage cells. Predicting lncRNA functions by using a “guilt-by-association” approach revealed that the functions of these 48 lncRNAs were enriched in ‘oligodendrocyte development and differentiation’. Additionally, bivalent genes are known to play essential roles during embryonic stem cell differentiation. We identified bivalent genes in NSC, OPC, and NFO, and found that some bivalent genes bound by OLIG2 are dynamically regulated during oligodendrocyte development. Importantly, we have identified AU-rich elements (AREs) in the 3’-UTRs of Olig2 mRNAs. We unveiled a previously unknown mechanism that, in addition to transcriptional regulation via DNA binding, OLIG2 could post-transcriptionally self-regulate expression through interaction with the 3’-UTR of its own mRNA.
Project description:The pMN domain is a restricted domain in the ventral spinal cords, defined by the expression of olig2 gene. The fate determination of pMN progenitors is highly temporally and spatially regulated, with motor neurons and oligodendrocyte progenitor cells (OPCs) developing sequentially. Insight into the heterogeneity and molecular programs of pMN progenitors is currently lacking. With the zebrafish model, we identified multiple states of neural progenitors using single-cell sequencing: proliferating progenitors, common progenitors for both motor neurons and OPCs, and restricted precursors for either motor neurons or OPCs. We found specific molecular programs for neural progenitor fate transition, and manipulations of representative genes in the motor neuron or OPC lineage confirmed their critical role in cell fate determination. Deciphering progenitor heterogeneity and molecular mechanisms for these transitions will elucidate the formation of complex neuron-glia networks in the central nervous system during development, and understand the basis of neurodevelopmental disorders.
Project description:The mature CNS contains PDGFRA+ ‘oligodendrocyte progenitor cells’ (OPC) which may remain quiescent, proliferate, or differentiate into oligodendrocytes. In human gliomas, rapidly proliferating Olig2+ cells resembling OPCs are frequently observed. We sought to identify, in vivo, candidate pathways uniquely required for OPC differentiation or quiescence. Using the bacTRAP methodology, we generated and analyzed mouse lines for translational profiling the major cells types (including OPCs), in the normal mouse brain. We then profiled oligodendoglial (Olig2+) cells from a mouse model of Pdgf-driven glioma. This analysis confirmed that Olig2+ tumor cells are most similar to OPCs, yet, it identified differences in key progenitor genes - candidates for promotion of differentiation or quiescence.
Project description:We show that a synthetic modified messenger RNA (smRNA)-based reprogramming method that leads to the generation of transgene-free OLs has been developed. An smRNA encoding a modified form of OLIG2, a key TF in OL development, in which the serine 147 phosphorylation site is replaced with alanine, OLIG2S147A, is designed to reprogram hiPSCs into OLs. We demonstrate that repeated administration of the smRNA encoding OLIG2 S147A lead to higher and more stable protein expression. Using the single-mutant OLIG2 smRNA morphogen, we establish a 6-day smRNA transfection protocol, and glial induction lead to rapid NG2+ OL progenitor cell (OPC) generation (> 70% purity) from hiPSC-derived neural progenitor cells (NPCs). The smRNA-induced NG2+ OPCs can mature into functional OLs in vitro and promote remyelination in vivo. Proteomic analysis of OLIG2-binding proteins indicates that OLIG2 is bound by the heat shock protein 70 (HSP70) complex. The HSP70 complex is bound more strongly to OLIG2 with the modified phosphorylation site than to wild-type OLIG2.
Project description:The mature CNS contains PDGFRA+ ‘oligodendrocyte progenitor cells’ (OPC) which may remain quiescent, proliferate, or differentiate into oligodendrocytes. In human gliomas, rapidly proliferating Olig2+ cells resembling OPCs are frequently observed. We sought to identify, in vivo, candidate pathways uniquely required for OPC differentiation or quiescence. Using the bacTRAP methodology, we generated and analyzed mouse lines for translational profiling the major cells types (including OPCs), in the normal mouse brain. We then profiled oligodendoglial (Olig2+) cells from a mouse model of Pdgf-driven glioma. This analysis confirmed that Olig2+ tumor cells are most similar to OPCs, yet, it identified differences in key progenitor genes - candidates for promotion of differentiation or quiescence. There are two datasets here. One characterizes the normal translational profiles of neurons, astrocytes, mature and immature oligodendrocytes. Each cell type was profiled in triplicate, from pools of at least two mice, and total RNA controls were collected in parallel. The second dataset includes translational profiles of Olig2 positive cells from tumors form several variations of a murine model of glioma. Each variation was collected at least in triplicate, and total RNA controls were analyzed in parallel. All translational profiles were generated using the Translating Ribosome Affinity Purification protocol.
Project description:The transforming growth factor beta (TGF-β) superfamily proteins are potent regulators of cellular development and differentiation. Long non-coding RNAs (lncRNAs) play widespread roles in spatial-temporal regulation of early development. However, the roles of lncRNAs regulated by nodal/TGF-β signaling is still elusive. Here, we showed a nodal-driven Smad induced lncRNA in mouse embryonic stem cells (mESCs), lncRNA-Smad7, which is divergently transcribed to Smad7, regulates cell fate determination through repressing Bmp2. Depletion of lncRNA-Smad7 dramatically impairs cardiomyocyte differentiation in mESCs. Moreover, LncRNA-Smad7 represses Bmp2 expression and binds at the promoter region of Bmp2. Importantly, knock-down Bmp2 rescues the defect of cardiomyocyte differentiation. Hence, we showed that lncRNA-Smad7 is antagonistic to BMP signaling in mESCs. Furthermore, lncRNA-Smad7 regulates cell fate determination between osteocytes and myocytes formation in C2C12 cells by repressing Bmp2. Thus, we provide new insights regarding the antagonistic effects between nodal/TGF-β and BMP signaling via lncRNA-Smad7.
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
