Genome-wide mapping of Olig2 targets in primary oligodendrocytes
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ABSTRACT:
ORGANISM(S): Rattus norvegicus
PROVIDER: GSE40506 | GEO | 2012/08/31
SECONDARY ACCESSION(S): PRJNA174195
REPOSITORIES: GEO
Similar Datasets
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/?-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 ?-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.
2012-08-31 | E-GEOD-40506 | biostudies-arrayexpress
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. We carried out microarray profiling analysis in the Sip1 conditional KO (cKO) mouse spinal cord to detail the change of global gene expression. Sip1 c/c;Olig1-Cre mouse spinal cord was collected at P14 for RNA extraction and Affymetrix microarray analysis. Sip1 c/+;Olig1-Cre littermate spinal cord was used as the control.
2012-08-31 | E-GEOD-40510 | biostudies-arrayexpress
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.
2012-08-31 | GSE40510 | GEO
Project description:Transforming growth factor (TGF)-β plays crucial roles in embryonic development and adult tissue homeostasis by eliciting various cellular responses in target cells. TGF-β signaling is principally mediated through receptor-activated Smad proteins, which regulate expression of target genes in cooperation with other DNA-binding transcriptionfactors (Smad cofactors). In this study, we found that the basic helix-loop-helix transcription factor Olig1 is a Smad cofactor involved in TGF-b-induced cell motility. Knockdown of Olig1 attenuated TGF-β-induced cell motility in chamber migration and wound healing assays. In contrast, Olig1 knockdown had no effect on bone morphogenetic protein-induced cell motility, TGF-β-induced cytostasis or epithelial-mesenchymal transition. Furthermore, we observed that cooperation of Smad2/3 with Olig1 is regulated by a peptidyl-prolyl cis/trans isomerase, Pin1. TGF-b-induced cell motility, induction of Olig1-regulated genes, and physical interaction between Smad2/3 and Olig1 were all inhibited after knockdown of Pin1, indicating a novel mode of regulation of Smad signaling. We also found that Olig1 interacts with the L3 loop of Smad3. Using a synthetic peptide corresponding to the L3 loop of Smad3, we succeeded in selectively inhibiting TGF-b-induced cell motility. These findings may lead to a new strategy for selective regulation of TGF-b-induced cellular responses. NMuMG cells were transfected with siRNAs (siControl, siOlig1 or siPin1) and treated with or without TGF-b for 1h. We compared genes affected by knockdown of Olig1 and that of Pin1.
2013-07-01 | E-GEOD-46405 | biostudies-arrayexpress
Project description:Transforming growth factor (TGF)-β plays crucial roles in embryonic development and adult tissue homeostasis by eliciting various cellular responses in target cells. TGF-β signaling is principally mediated through receptor-activated Smad proteins, which regulate expression of target genes in cooperation with other DNA-binding transcriptionfactors (Smad cofactors). In this study, we found that the basic helix-loop-helix transcription factor Olig1 is a Smad cofactor involved in TGF-b-induced cell motility. Knockdown of Olig1 attenuated TGF-β-induced cell motility in chamber migration and wound healing assays. In contrast, Olig1 knockdown had no effect on bone morphogenetic protein-induced cell motility, TGF-β-induced cytostasis or epithelial-mesenchymal transition. Furthermore, we observed that cooperation of Smad2/3 with Olig1 is regulated by a peptidyl-prolyl cis/trans isomerase, Pin1. TGF-b-induced cell motility, induction of Olig1-regulated genes, and physical interaction between Smad2/3 and Olig1 were all inhibited after knockdown of Pin1, indicating a novel mode of regulation of Smad signaling. We also found that Olig1 interacts with the L3 loop of Smad3. Using a synthetic peptide corresponding to the L3 loop of Smad3, we succeeded in selectively inhibiting TGF-b-induced cell motility. These findings may lead to a new strategy for selective regulation of TGF-b-induced cellular responses.
2013-07-01 | GSE46405 | GEO
Project description:Background & Aims: Although hepcidin expression was shown to be induced by the BMP signaling pathway, it is not yet known how iron regulates hepcidin and which of the BMP molecules is the endogenous regulator of iron homeostasis in vivo. We therefore assessed liver transcription profiles of mice fed an iron-deficient or an iron-enriched diet and looked for genes that were regulated similarly to hepcidin in that context. Methods: Genome-wide liver expression profiles of mice of the B6 and D2 genetic backgrounds subjected to iron-deficient, -balanced, or -enriched diets were obtained using Agilent Whole Genome microarrays. Real-time quantitative-PCR and western-blots were used to confirm microarray results and compare gene expression variations induced by secondary iron deficiency or iron overload with those consecutive to Smad4 or Hamp1-deficiency. Results: Among 1419 transcripts significantly modulated by the dietary iron content, four were regulated similarly to the hepcidin genes Hamp1 and Hamp2. They are coding for Bmp6, the regulator of Bmp/Smad signal transduction Smad7, the negative regulator of basic helix-loop-helix (bHLH) proteins Id1, and a protein with a bHLH domain, Atoh8. The iron overload developed by Smad4 and Hamp1-deficient mice also increased Bmp6 transcription. Body iron stores influence Smad1/5/8 phosphorylation and, as shown by analysis of mice with liver-specific disruption of Smad4, the binding partner for the receptor-activated Smads is necessary for activation of Smad7, Id1, and Atoh8 transcription by iron. Conclusions: Liver expression of Bmp6, Smad7, Id1, and Atoh8 is regulated by body iron stores and may participate in hepcidin regulation through the Bmp/Smad pathway. Keywords: response to dietary iron content
2008-07-07 | GSE10421 | GEO
Project description:The progressive loss of CNS myelin in patients with multiple sclerosis (MS) has been proposed to result from the combined effects of damage to oligodendrocytes and failure of remyelination. A common feature of demyelinated lesions is the presence of oligodendrocyte precursors (OLPs) blocked at a premyelinating stage. However, the mechanistic basis for inhibition of myelin repair is incompletely understood. To identify novel regulators of OLP differentiation, potentially dysregulated during repair, we performed a genome-wide screen of 1040 transcription factor-encoding genes expressed in remyelinating rodent lesions. We report that M-bM-^HM-<50 transcription factor-encoding genes show dynamic expression during repair and that expression of the Wnt pathway mediator Tcf4 (aka Tcf7l2) within OLPs is specific to lesionedM-bM-^@M-^Tbut not normalM-bM-^@M-^Tadult white matter. We report that M-NM-2-catenin signaling is active during oligodendrocyte development and remyelination in vivo. Moreover, we observed similar regulation of Tcf4 in the developing human CNS and lesions of MS. Data mining revealed elevated levels of Wnt pathway mRNA transcripts and proteins within MS lesions, indicating activation of the pathway in this pathological context. We show that dysregulation of WntM-bM-^@M-^SM-NM-2-catenin signaling in OLPs results in profound delay of both developmental myelination and remyelination, based on (1) conditional activation of M-NM-2-catenin in the oligodendrocyte lineage in vivo and (2) findings from APCMin mice, which lack one functional copy of the endogenous Wnt pathway inhibitor APC. Together, our findings indicate that dysregulated WntM-bM-^@M-^SM-NM-2-catenin signaling inhibits myelination/remyelination in the mammalian CNS. Evidence of Wnt pathway activity in human MS lesions suggests that its dysregulation might contribute to inefficient myelin repair in human neurological disorders. 12 samples total. Two variables in the experiment: genotype (wild type or Olig2cre/DA-Cat) and Developmental stage (Day 4 or Day 15). 4 phenotypes in total with 3 biological replicates for each phenotype.
2009-12-10 | E-GEOD-19403 | biostudies-arrayexpress
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.
2016-02-19 | E-GEOD-65119 | biostudies-arrayexpress
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.
2022-10-19 | GSE178136 | GEO
Project description:Wnt signaling plays an essential role in developmental and regenerative myelination in the CNS. The Wnt signaling pathway is comprised of multiple regulatory layers; thus, how these processes are coordinated to orchestrate oligodendrocyte development remains unclear. Here we show CK2α, a Wnt/β-catenin signaling Ser/Thr kinase, phosphorylates Daam2, inhibiting its function and Wnt-activity during oligodendrocyte development. Intriguingly, we found Daam2 phosphorylation differentially impacts distinct stages of oligodendrocyte development, accelerating early differentiation followed by decelerating maturation and myelination. Application towards white matter injury revealed CK2α-mediated Daam2 phosphorylation plays a protective role for developmental and behavioral recovery after neonatal hypoxia, while promoting myelin repair following adult demyelination. Together, our findings identify a novel regulatory node in the Wnt pathway that regulates oligodendrocyte development via protein phosphorylation-induced signaling complex instability and highlights a new biological mechanism for myelin restoration.
2023-07-13 | GSE236976 | GEO