scholarly journals WNT signaling suppresses oligodendrogenesis via Ngn2-dependent direct inhibition of Olig2 expression

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Min Jiang ◽  
Dan Yu ◽  
Binghua Xie ◽  
Hao Huang ◽  
Wenwen Lu ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Motor Neurons ◽  
Promoter Activity ◽  
Neural Progenitor Cells ◽  
Luciferase Reporter ◽  
Oligodendrocyte Precursor Cells ◽  
Reporter Assay ◽  
Direct Inhibition ◽  
In Ovo ◽  
Oligodendrocyte Precursor

AbstractOlig2 transcription factor is essential for the maintenance of neural progenitor cells (NPCs) in the pMN domain and their sequential specification into motor neurons (MNs) and oligodendrocyte precursor cells (OPCs). The expression of Olig2 rapidly declines in newly generated MNs. However, Olig2 expression persists in later-born OPCs and antagonizes the expression of MN-related genes. The mechanism underlying the differential expression of Olig2 in MNs and oligodendrocytes remains unknown. Here, we report that activation of WNT/β-catenin signaling in pMN lineage cells abolished Olig2 expression coupled with a dramatic increase of Ngn2 expression. Luciferase reporter assay showed that Ngn2 inhibited Olig2 promoter activity. Overexpression of Ngn2-EnR transcription repressor blocked the expression of Olig2 in ovo. Our results suggest that down-regulation of WNT-Ngn2 signaling contributes to oligodendrogenesis from the pMN domain and the persistent Olig2 expression in OPCs.

scholarly journals Prdm8 regulates pMN progenitor specification for motor neuron and oligodendrocyte fates by modulating the Shh signaling response

Development ◽  
2020 ◽  
Vol 147 (16) ◽  
pp. dev191023 ◽  
Author(s):  
Kayt Scott ◽  
Rebecca O'Rourke ◽  
Austin Gillen ◽  
Bruce Appel
Keyword(s):  
Motor Neuron ◽  
Cell Fate ◽  
Motor Neurons ◽  
Oligodendrocyte Precursor Cells ◽  
Cell Fate Specification ◽  
Cell Fates ◽  
Shh Signaling ◽  
Fate Specification ◽  
The People ◽  
Oligodendrocyte Precursor

ABSTRACTSpinal cord pMN progenitors sequentially produce motor neurons and oligodendrocyte precursor cells (OPCs). Some OPCs differentiate rapidly as myelinating oligodendrocytes, whereas others remain into adulthood. How pMN progenitors switch from producing motor neurons to OPCs with distinct fates is poorly understood. pMN progenitors express prdm8, which encodes a transcriptional repressor, during motor neuron and OPC formation. To determine whether prdm8 controls pMN cell fate specification, we used zebrafish as a model system to investigate prdm8 function. Our analysis revealed that prdm8 mutant embryos have fewer motor neurons resulting from a premature switch from motor neuron to OPC production. Additionally, prdm8 mutant larvae have excess oligodendrocytes and a concomitant deficit of OPCs. Notably, pMN cells of mutant embryos have elevated Shh signaling, coincident with the motor neuron to OPC switch. Inhibition of Shh signaling restored the number of motor neurons to normal but did not rescue the proportion of oligodendrocytes. These data suggest that Prdm8 regulates the motor neuron-OPC switch by controlling the level of Shh activity in pMN progenitors, and also regulates the allocation of oligodendrocyte lineage cell fates.This article has an associated ‘The people behind the papers’ interview.

scholarly journals Sulfatase 2 Modulates Fate Change from Motor Neurons to Oligodendrocyte Precursor Cells through Coordinated Regulation of Shh Signaling with Sulfatase 1

2017 ◽  
Vol 39 (5) ◽  
pp. 361-374 ◽  
Author(s):  
Wen Jiang ◽  
Yugo Ishino ◽  
Hirokazu Hashimoto ◽  
Kazuko Keino-Masu ◽  
Masayuki Masu ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Expression Pattern ◽  
Motor Neurons ◽  
Expression Patterns ◽  
Precursor Cells ◽  
Oligodendrocyte Precursor Cells ◽  
Shh Signaling ◽  
Sulfatase Activity ◽  
Oligodendrocyte Precursor ◽  
Ventral Spinal Cord

Sulfatases (Sulfs) are a group of endosulfatases consisting of Sulf1 and Sulf2, which specifically remove sulfate from heparan sulfate proteoglycans. Although several studies have shown that Sulf1 acts as a regulator of sonic hedgehog (Shh) signaling during embryonic ventral spinal cord development, the detailed expression pattern and function of Sulf2 in the spinal cord remains to be determined. In this study, we found that Sulf2 also modulates the cell fate change from motor neurons (MNs) to oligodendrocyte precursor cells (OPCs) by regulating Shh signaling in the mouse ventral spinal cord in coordination with Sulf1. In the mouse, Sulf mRNAs colocalize with Shh mRNA and gradually expand dorsally from embryonic day (E) 10.5 to E12.5, following strong Patched1 signals (a target gene of Shh signaling). This coordinated expression pattern led us to hypothesize that in the mouse, strong Shh signaling is induced when Shh is released by Sulf1/2, and this strong Shh signaling subsequently induces the dorsal expansion of Shh and Sulf1/2 expression. Consistent with this hypothesis, in the ventral spinal cord of Sulf1 knockout (KO) or Sulf2 KO mice, the expression patterns of Shh and Patched1 differed from that in wild-type mice. Moreover, the position of the pMN and p3 domains were shifted ventrally, MN generation was prolonged, and OPC generation was delayed at E12.5 in both Sulf1 KO and Sulf2 KO mice. These results demonstrated that in addition to Sulf1, Sulf2 also plays an important and overlapping role in the MN-to-OPC fate change by regulating Shh signaling in the ventral spinal cord. However, neither Sulf1 nor Sulf2 could compensate for the loss of the other in the developing mouse spinal cord. In vitro studies showed no evidence of an interaction between Sulf1 and Sulf2 that could increase sulfatase activity. Furthermore, Sulf1/2 double heterozygote and Sulf1/2 double KO mice exhibited phenotypes similar to the Sulf1 KO and Sulf2 KO mice. These results indicate that there is a threshold for sulfatase activity (which is likely reflected in the dose of Shh) required to induce the MN-to-OPC fate change, and Shh signaling requires the coordinated activity of Sulf1 and Sulf2 in order to reach that threshold in the mouse ventral spinal cord.

scholarly journals Specification and maintenance of oligodendrocyte precursor cells from neural progenitor cells: involvement of microRNA-7a

2012 ◽  
Vol 23 (15) ◽  
pp. 2867-2877 ◽  
Author(s):  
Xianghui Zhao ◽  
Jiang Wu ◽  
Minhua Zheng ◽  
Fang Gao ◽  
Gong Ju
Keyword(s):  
Progenitor Cells ◽  
Cell Fate ◽  
Neural Progenitor Cells ◽  
Neural Progenitor ◽  
Precursor Cells ◽  
Specific Gene ◽  
Oligodendrocyte Precursor Cells ◽  
Embryonic Mouse ◽  
New Strategy ◽  
Oligodendrocyte Precursor

The generation of myelinating cells from multipotential neural stem cells in the CNS requires the initiation of specific gene expression programs in oligodendrocytes (OLs). We reasoned that microRNAs (miRNAs) could play an important role in this process by regulating genes crucial for OL development. Here we identified miR-7a as one of the highly enriched miRNAs in oligodendrocyte precursor cells (OPCs), overexpression of which in either neural progenitor cells (NPCs) or embryonic mouse cortex promoted the generation of OL lineage cells. Blocking the function of miR-7a in differentiating NPCs led to a reduction in OL number and an expansion of neuronal populations simultaneously. We also found that overexpression of this miRNA in purified OPC cultures promoted cell proliferation and inhibited further maturation. In addition, miR-7a might exert the effects just mentioned partially by directly repressing proneuronal differentiation factors including Pax6 and NeuroD4, or proOL genes involved in oligodendrocyte maturation. These results suggest that miRNA pathway is essential in determining cell fate commitment for OLs and thus providing a new strategy for modulating this process in OL loss diseases.

scholarly journals Loss of the third C2H2 zinc finger of chicken KLF7 affects its transcriptional regulation activities in adipose tissue

2019 ◽  
Vol 52 (1) ◽  
pp. 84-90 ◽  
Author(s):  
Zhiwei Zhang ◽  
Chunyan Wu ◽  
Tao Lin ◽  
Yuechan Chen
Keyword(s):  
Transcriptional Regulation ◽  
Zinc Finger ◽  
Promoter Activity ◽  
Mammalian Species ◽  
Luciferase Reporter ◽  
Reporter Assay ◽  
Wild Type ◽  
C2h2 Zinc Finger ◽  
The Third ◽  
Significant Difference

Abstract KLF7, one of candidate genes in neurotherapy and metabolic syndrome, has been studied in adipogenesis of mammalian species and birds. However, the effect of the third C2H2 zinc finger of KLF7 for its transcriptional regulation in adipogenesis has not been well understood. Here, the wild-type chicken KLF7 (KLF7) overexpression plasmid, pCMV-myc-KLF7, and two plasmids of chicken KLF7 mutants, i.e. pCMV-myc-KLF7m1 with half of the third zinc finger (KLF7m1) and pCMV-myc-KLF7m2 without the third zinc finger (KLF7m2), were constructed. Luciferase reporter assay in DF1 cells showed that the effect of chicken KLF7 overexpression on the promoter activity of LPL was greater than those of KLF7m1 and KLF7m2 (P < 0.05). There was no significant difference among the overexpression of KLF7, KLF7m1 and KLF7m2 on the promoter activities of FASN, C/EBPα and FABP4 (P > 0.05). Additionally, the effects of KLF7, KLF7m1 and KLF7m2 overexpression on the promoter activity of PPARγ were different. KLF7 overexpression had no significant effect on the PPARγ promoter activity (P > 0.05), KLF7m1 overexpression suppressed PPARγ promoter activity (P < 0.05), while KLF7m2 overexpression facilitated the promoter activity of PPARγ (P < 0.05), consistent with the results of western blot analysis. Our results suggested that the third zinc finger of chicken KLF7 may play a role in its transcriptional regulation of LPL and PPARγ but has no effect on its regulation of C/EBPα, FASN and FABP4. The third zinc finger of KLF7 might be a target for the treatment of metabolic disorder in chicken.

Role of AP2 consensus sites in regulation of rat Npt2 (sodium-phosphate cotransporter) promoter

2000 ◽  
Vol 278 (3) ◽  
pp. F406-F416 ◽  
Author(s):  
C. Shachaf ◽  
K. L. Skorecki ◽  
M. Tzukerman
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Proximal Tubule ◽  
Cell Lines ◽  
Promoter Activity ◽  
Promoter Sequence ◽  
Luciferase Reporter ◽  
Inverted Repeats ◽  
Proximal Tubule Cell ◽  
Flanking Sequence

Expression of the Npt2 gene, encoding the type II sodium-dependent phosphate cotransporter, is restricted to renal proximal tubule epithelium. We have isolated a 4,740-bp fragment of the 5′-flanking sequence of the rat Npt2 gene, identified the transcription initiation site, and demonstrated that this 5′-flanking sequence drives luciferase-reporter gene expression, following transfection in the proximal tubule cell-derived opossum kidney (OK) cell line but not in unrelated cell lines. Analysis of the promoter sequence revealed the presence of 10 consensus binding motifs for the AP2 transcription factor. Transient transfection assays revealed an important effect of the number of tandemly repeated AP2 sites in enhancing promoter activity. The promoter sequence also revealed a pair of inverted repeats enclosing 1,324 bp of intervening sequence and containing 8 of the total 10 AP2 consensus sites in the promoter sequence. Deletion or reversal of orientation of the distal inverted repeat resulted in marked enhancement of promoter activity. Electrophoretic mobility shift analysis revealed a distinct pattern of transcription factor binding to oligonucleotides containing AP2 sites, using nuclear extracts from OK cells, compared with unrelated cell lines. Taken together, these results suggest an important role for AP2 consensus binding sites in regulating Npt2 gene expression and suggest a mechanism of regulation mediated by the interaction of inverted repeats enclosing these sites.

scholarly journals REST corepressors RCOR1 and RCOR2 and the repressor INSM1 regulate the proliferation–differentiation balance in the developing brain

2017 ◽  
Vol 114 (3) ◽  
pp. E406-E415 ◽  
Author(s):  
Caitlin E. Monaghan ◽  
Tamilla Nechiporuk ◽  
Sophia Jeng ◽  
Shannon K. McWeeney ◽  
Jianxun Wang ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Neural Progenitors ◽  
Developing Brain ◽  
Oligodendrocyte Precursor Cells ◽  
Embryonic Mouse ◽  
Cycle Arrest ◽  
Proliferation And Differentiation ◽  
Number Of Genes ◽  
Morphological Processes ◽  
Oligodendrocyte Precursor

The transcriptional events that lead to the cessation of neural proliferation, and therefore enable the production of proper numbers of differentiated neurons and glia, are still largely uncharacterized. Here, we report that the transcription factor Insulinoma-associated 1 (INSM1) forms complexes with RE1 Silencing Transcription factor (REST) corepressors RCOR1 and RCOR2 in progenitors in embryonic mouse brain. Mice lacking both RCOR1 and RCOR2 in developing brain die perinatally and generate an abnormally high number of neural progenitors at the expense of differentiated neurons and oligodendrocyte precursor cells. In addition, Rcor1/2 deletion detrimentally affects complex morphological processes such as closure of the interganglionic sulcus. We find that INSM1, a transcription factor that induces cell-cycle arrest, is coexpressed with RCOR1/2 in a subset of neural progenitors and forms complexes with RCOR1/2 in embryonic brain. Further, the Insm1−/− mouse phenocopies predominant brain phenotypes of the Rcor1/2 knockout. A large number of genes are concordantly misregulated in both knockout genotypes, and a majority of the down-regulated genes are targets of REST. Rest transcripts are up-regulated in both knockouts, and reducing transcripts to control levels in the Rcor1/2 knockout partially rescues the defect in interganglionic sulcus closure. Our findings indicate that an INSM1/RCOR1/2 complex controls the balance of proliferation and differentiation during brain development.

scholarly journals Nuclear receptors RXRα:RARα are repressors for human MRP3 expression

2007 ◽  
Vol 292 (5) ◽  
pp. G1221-G1227 ◽  
Author(s):  
Wensheng Chen ◽  
Shi-Ying Cai ◽  
Shuhua Xu ◽  
Lee A. Denson ◽  
Carol J. Soroka ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Promoter Activity ◽  
Regulatory Elements ◽  
Luciferase Reporter ◽  
Dependent Manner ◽  
Site Mutation ◽  
Transcription Factor Sp1 ◽  
Gc Box ◽  
Rna Knockdown ◽  
Interfering Rna

Multidrug resistance-associated protein MRP3/Mrp3 (ABCC3) is upregulated in cholestasis, an adaptive response that may protect the liver from accumulation of toxic compounds, such as bile salts and bilirubin conjugates. However, the mechanism of this upregulation is poorly understood. We and others have previously reported that fetoprotein transcription factor/liver receptor homolog-1 is an activator of MRP3/Mrp3 expression. In searching for additional regulatory elements in the human MRP3 promoter, we have now identified nuclear receptor retinoic X receptor-α:retinoic acid receptor-α (RXRα:RARα) as a repressor of MRP3 activation by transcription factor Sp1. A luciferase reporter assay demonstrated that cotransfection of transcription factor Sp1 stimulates the MRP3 promoter activity and that additions of RXRα:RARα abrogated this activation in a dose-dependent manner. Site mutations and gel shift assays have identified a Sp1 binding GC box motif at −113 to −108 nts upstream from the MRP3 translation start site, where RXRα:RARα specifically reduced Sp1 binding to this site. Mutation of the GC box also reduced MRP3 promoter activity. The functional role of RXRα:RARα as a repressor of MRP3 expression was further confirmed by RARα small-interfering RNA knockdown in HepG2 cells, which upregulated endogenous MRP3 expression. In summary, our results indicate that activator Sp1 and repressor RXRα:RARα act in concert to regulate MRP3 expression. Since RXRα:RARα expression is diminished by cholestatic liver injury, loss of RXRα:RARα may lead to upregulation of MRP3/Mrp3 expression in these disorders.

scholarly journals Direct reprogramming of oligodendrocyte precursor cells into GABAergic inhibitory neurons by a single homeodomain transcription factor Dlx2

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Linda L. Boshans ◽  
Heun Soh ◽  
William M. Wood ◽  
Timothy M. Nolan ◽  
Ion I. Mandoiu ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Progenitor Cells ◽  
Inhibitory Neuron ◽  
Precursor Cells ◽  
Synaptic Proteins ◽  
Inhibitory Neurons ◽  
Oligodendrocyte Precursor Cells ◽  
Molecular Logic ◽  
Neuronal Fate ◽  
Oligodendrocyte Precursor

AbstractOligodendrocyte precursor cells (NG2 glia) are uniformly distributed proliferative cells in the mammalian central nervous system and generate myelinating oligodendrocytes throughout life. A subpopulation of OPCs in the neocortex arises from progenitor cells in the embryonic ganglionic eminences that also produce inhibitory neurons. The neuronal fate of some progenitor cells is sealed before birth as they become committed to the oligodendrocyte lineage, marked by sustained expression of the oligodendrocyte transcription factor Olig2, which represses the interneuron transcription factor Dlx2. Here we show that misexpression of Dlx2 alone in postnatal mouse OPCs caused them to switch their fate to GABAergic neurons within 2 days by downregulating Olig2 and upregulating a network of inhibitory neuron transcripts. After two weeks, some OPC-derived neurons generated trains of action potentials and formed clusters of GABAergic synaptic proteins. Our study revealed that the developmental molecular logic can be applied to promote neuronal reprogramming from OPCs.

The g.763G>C SNP of the bovine FASN gene affects its promoter activity via Sp-mediated regulation: implications for the bovine lactating mammary gland

2008 ◽  
Vol 34 (2) ◽  
pp. 144-148 ◽  
Author(s):  
Laura Ordovás ◽  
Rosa Roy ◽  
Sandra Pampín ◽  
Pilar Zaragoza ◽  
Rosario Osta ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Mammary Gland ◽  
Milk Fat ◽  
Promoter Activity ◽  
Transcription Factor Binding ◽  
Fat Content ◽  
Luciferase Reporter ◽  
Binding Ability ◽  
Factor Binding ◽  
Lactating Mammary Gland

Fatty acid synthase (FASN) is an enzyme that catalyzes de novo synthesis of fatty acids in cells. The bovine FASN gene maps to BTA 19, where several quantitative trait loci for fat-related traits have been described. Our group recently reported the identification of a single nucleotide polymorphism (SNP), g.763G>C, in the bovine FASN 5′ flanking region that was significantly associated with milk fat content in dairy cattle. The g.763G>C SNP was part of a GC-rich region that may constitute a cis element for members of the Sp transcription factor family. Thus the SNP could alter the transcription factor binding ability of the FASN promoter and consequently affect the promoter activity of the gene. However, the functional consequences of the SNP on FASN gene expression are unknown. The present study was therefore directed at elucidating the underlying molecular mechanism that could explain the association of the SNP with milk fat content. Three cellular lines (3T3L1, HepG2, and MCF-7) were used to test the promoter and the transcription factor binding activities by luciferase reporter assays and electrophoretic mobility shift assays, respectively. Band shift assays were also carried out with nuclear extracts from lactating mammary gland (LMG) to further investigate the role of the SNP in this tissue. Our results demonstrate that the SNP alters the bovine FASN promoter activity in vitro and the Sp1/Sp3 binding ability of the sequence. In bovine LMG, the specific binding of Sp3 may account for the association with milk fat content.

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