scholarly journals MOZ and BMI1 play opposing roles during Hox gene activation in ES cells and in body segment identity specification in vivo

2015 ◽  
Vol 112 (17) ◽  
pp. 5437-5442 ◽  
Author(s):  
Bilal N. Sheikh ◽  
Natalie L. Downer ◽  
Belinda Phipson ◽  
Hannah K. Vanyai ◽  
Andrew J. Kueh ◽  
...  
Keyword(s):  
Gene Expression ◽  
Es Cells ◽  
Gene Activation ◽  
Embryonic Stem ◽  
Mrna Levels ◽  
Body Segment ◽  
Initial Activation ◽  
Activation Phase

Hox genes underlie the specification of body segment identity in the anterior–posterior axis. They are activated during gastrulation and undergo a dynamic shift from a transcriptionally repressed to an active chromatin state in a sequence that reflects their chromosomal location. Nevertheless, the precise role of chromatin modifying complexes during the initial activation phase remains unclear. In the current study, we examined the role of chromatin regulators during Hox gene activation. Using embryonic stem cell lines lacking the transcriptional activator MOZ and the polycomb-family repressor BMI1, we showed that MOZ and BMI1, respectively, promoted and repressed Hox genes during the shift from the transcriptionally repressed to the active state. Strikingly however, MOZ but not BMI1 was required to regulate Hox mRNA levels after the initial activation phase. To determine the interaction of MOZ and BMI1 in vivo, we interrogated their role in regulating Hox genes and body segment identity using Moz;Bmi1 double deficient mice. We found that the homeotic transformations and shifts in Hox gene expression boundaries observed in single Moz and Bmi1 mutant mice were rescued to a wild type identity in Moz;Bmi1 double knockout animals. Together, our findings establish that MOZ and BMI1 play opposing roles during the onset of Hox gene expression in the ES cell model and during body segment identity specification in vivo. We propose that chromatin-modifying complexes have a previously unappreciated role during the initiation phase of Hox gene expression, which is critical for the correct specification of body segment identity.

scholarly journals Developmental regulation of yolk sac hematopoiesis by Krüppel-like factor 6

Blood ◽  
2006 ◽  
Vol 107 (4) ◽  
pp. 1357-1365 ◽  
Author(s):  
Nobuyuki Matsumoto ◽  
Atsushi Kubo ◽  
Huixian Liu ◽  
Kuniharu Akita ◽  
Friedrich Laub ◽  
...  
Keyword(s):  
Developmental Regulation ◽  
Es Cells ◽  
Embryonic Stem ◽  
Early Embryo ◽  
Yolk Sac ◽  
Homozygous Mutation ◽  
Mesoderm Induction ◽  
Mrna Levels ◽  
Mouse Development

Krüppel-like factor 6 (KLF6) is a member of a growing family of transcription factors that share a common 3 C2H2 zinc finger DNA binding domain and have broad activity in regulating proliferation and development. We have previously established that Klf6 is expressed in neuronal tissue, hindgut, heart, lung, kidney, and limb buds during midgestation. To explore the potential role of Klf6 in mouse development, we analyzed Klf6-/- mice and found that the homozygous mutation is embryonic lethal by embryonic day (E) 12.5 and associated with markedly reduced hematopoiesis and poorly organized yolk sac vascularization. Additionally, mRNA levels of Scl and Gata1 were reduced by approximately 80% in Klf6-/- yolk sacs. To further analyze this phenotype, we generated Klf6-/- embryonic stem (ES) cells by homologous recombination, and compared their capacity to differentiate into the hematopoietic lineage with that of either Klf6+/- or Klf6+/+ ES cells. Consistent with the phenotype in the early embryo, Klf6-/- ES cells displayed significant hematopoietic defects following differentiation into EBs. Prolongation of epiblast-like cells and delays in mesoderm induction were also observed in the Klf6-/- EBs, associated with delayed expression of Brachyury, Klf1, and Gata1. Forced expression of KLF6 using a tet-inducible system enhanced the hematopoietic potential of wild-type EBs. Collectively, these findings implicate Klf6 in ES-cell differentiation and hematopoiesis.

Analysis of the role of interleukin-1β (IL-1β)in vivo by gene targeting in embryonic stem (ES) cells

Cytokine ◽  
1994 ◽  
Vol 6 (5) ◽  
pp. 574
Author(s):  
L. Shornick ◽  
P. De Togni ◽  
S. Mariathasan ◽  
A. Fick ◽  
J. Goellner ◽  
...  
Keyword(s):  
Gene Targeting ◽  
Es Cells ◽  
Embryonic Stem ◽  
Interleukin 1Β

scholarly journals Foxa1 and Foxa2 Regulate α-Cell Differentiation, Glucagon Biosynthesis, and Secretion

Endocrinology ◽  
2014 ◽  
Vol 155 (10) ◽  
pp. 3781-3792 ◽  
Author(s):  
Mounia Heddad Masson ◽  
Caroline Poisson ◽  
Audrey Guérardel ◽  
Aline Mamin ◽  
Jacques Philippe ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Differentiation ◽  
Target Genes ◽  
Adult Mouse ◽  
Glucagon Secretion ◽  
Mrna Levels ◽  
Forkhead Box ◽  
Interfering Rna

Abstract The Forkhead box A transcription factors are major regulators of glucose homeostasis. They show both distinct and redundant roles during pancreas development and in adult mouse β-cells. In vivo ablation studies have revealed critical implications of Foxa1 on glucagon biosynthesis and requirement of Foxa2 in α-cell terminal differentiation. In order to examine the respective role of these factors in mature α-cells, we used small interfering RNA (siRNA) directed against Foxa1 and Foxa2 in rat primary pancreatic α-cells and rodent α-cell lines leading to marked decreases in Foxa1 and Foxa2 mRNA levels and proteins. Both Foxa1 and Foxa2 control glucagon gene expression specifically through the G2 element. Although we found that Foxa2 controls the expression of the glucagon, MafB, Pou3f4, Pcsk2, Nkx2.2, Kir6.2, and Sur1 genes, Foxa1 only regulates glucagon gene expression. Interestingly, the Isl1 and Gipr genes were not controlled by either Foxa1 or Foxa2 alone but by their combination. Foxa1 and Foxa2 directly activate and bind the promoter region the Nkx2.2, Kir6.2 and Sur1, Gipr, Isl1, and Pou3f4 genes. We also demonstrated that glucagon secretion is affected by the combined effects of Foxa1 and Foxa2 but not by either one alone. Our results indicate that Foxa1 and Foxa2 control glucagon biosynthesis and secretion as well as α-cell differentiation with both common and unique target genes.

TET2 Favors Mesoderm and Hematopoietic Differentiation in Human Embryonic Stem Cells

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2418-2418
Author(s):  
Barbara da Costa Reis Monte Mor ◽  
Thierry Langlois ◽  
Nathalie Droin ◽  
Elodie Pronier ◽  
Jean-Pierre Le Couédic ◽  
...  
Keyword(s):  
Gene Expression ◽  
Conflicts Of Interest ◽  
Es Cells ◽  
Embryonic Stem ◽  
Hematopoietic Differentiation ◽  
Hematopoietic Progenitors ◽  
Hematopoietic Development ◽  
Neuronal Genes ◽  
Hes Cells

Abstract Abstract 2418 TET2 belongs to the TET family proteins that catalyze 5-methylcytosine (5mc) to 5-hydroxymethylcytosine (hmc) and plays an important role in normal and malignant adult hematopoiesis. The role of TET2 in human hematopoietic development remains unknown. Here we show that TET2 is expressed at low level in human embryonic stem (hES) cell lines and that its expression increases during hematopoietic differentiation in three different hES. TET2 knockdown does not modify hmc level and pluripotent properties of ES cells. However TET2 depletion by two different shRNA skewed differentiation into neuroectoderm at the expense of endoderm and mesoderm. This was associated with a decrease or an increase in promoter methylation of neuroectoderm and meso/endoderm genes, respectively during hES specification. Subsequently, we observed a decrease in hematopoietic progenitors (CD34+CD43+) and their cloning capacities due to a marked increase in apoptosis. Alteration of hematopoietic differentiation was coupled with a profound alteration in gene expression with up and down regulated genes including the abnormal expression of neuronal genes in hematopoietic cells. Thus our results suggest that TET2 regulates embryonic development by inhibiting neuroectoderm specification and enabling hematopoietic differentiation in hES cells. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Ape1 regulates hematopoietic differentiation of embryonic stem cells through its redox functional domain

Blood ◽  
2006 ◽  
Vol 109 (5) ◽  
pp. 1917-1922 ◽  
Author(s):  
Gang-Ming Zou ◽  
Mei-Hua Luo ◽  
April Reed ◽  
Mark R. Kelley ◽  
Mervin C. Yoder
Keyword(s):  
Gene Expression ◽  
Dna Repair ◽  
Redox Regulation ◽  
Es Cells ◽  
Embryonic Stem ◽  
Redox Activity ◽  
Normal Embryo ◽  
Functional Domain ◽  
Regulation Of Transcription

Abstract Ape1 is a molecule with dual functions in DNA repair and redox regulation of transcription factors. In Ape1-deficient mice, embryos do not survive beyond embryonic day 9, indicating that this molecule is required for normal embryo development. Currently, direct evidence of the role of Ape1 in regulating hematopoiesis is lacking. We used the embryonic stem (ES) cell differentiation system and an siRNA approach to knockdown Ape1 gene expression to test the role of Ape1 in hematopoiesis. Hemangioblast development from ES cells was reduced 2- to 3-fold when Ape1 gene expression was knocked down by Ape1-specific siRNA, as was primitive and definitive hematopoiesis. Impaired hematopoiesis was not associated with increased apoptosis in siRNA-treated cells. To begin to explore the mechanism whereby Ape1 regulates hematopoiesis, we found that inhibition of the redox activity of Ape1 with E3330, a specific Ape1 redox inhibitor, but not Ape1 DNA repair activity, which was blocked using the small molecule methoxyamine, affected cytokine-mediated hemangioblast development in vitro. In summary, these data indicate Ape1 is required in normal embryonic hematopoiesis and that the redox function, but not the repair endonuclease activity, of Ape1 is critical in normal embryonic hematopoietic development.

Targeted transgenesis at the HPRT locus: an efficient strategy to achieve tightly controlled in vivo conditional expression with the tet system

2009 ◽  
Vol 37 (2) ◽  
pp. 140-146 ◽  
Author(s):  
G. Palais ◽  
A. Nguyen Dinh Cat ◽  
H. Friedman ◽  
N. Panek-Huet ◽  
A. Millet ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transgene Expression ◽  
Germ Line ◽  
Es Cells ◽  
Embryonic Stem ◽  
Single Copy ◽  
Selection Strategy ◽  
Conditional Expression ◽  
Hprt Locus

The tet-inducible system has been widely used to achieve conditional gene expression in genetically modified mice. To alleviate the frequent difficulties associated with recovery of relevant transgenic founders, we tested whether a controlled strategy of transgenesis would support reliable cell-specific, doxycycline (Dox)-controlled transgene expression in vivo. Taking advantage of the potent hypoxanthine-aminopterin-thymidine selection strategy and an embryonic stem (ES) cell line supporting efficient germ-line transmission, we used hypoxanthine phosphoribosyltransferase ( HPRT) targeting to insert a single copy tet-inducible construct designed to allow both glucocorticoid receptor (GR) and β-galactosidase (β-Gal) expression. Conditional, Dox-dependent GR and β-Gal expression was evidenced in targeted ES cells. Breeding ES-derived single copy transgenic mice with mice bearing appropriate tet transactivators resulted in β-Gal expression both qualitatively and quantitatively similar to that observed in mice with random integration of the same construct. Interestingly, GR expression in mice was dependent on transgene orientation in the HPRT locus while embryonic stem cell expression was not. Thus, a conditional construct inserted in single copy and in predetermined orientation at the HPRT locus demonstrated a Dox-dependent gene expression phenotype in adult mice suggesting that controlled insertion of tet-inducible constructs at the HPRT locus can provide an efficient alternative strategy to reproducibly generate animal models with tetracycline-induced transgene expression.

scholarly journals Negative Regulation of BRCA1 Gene Expression by HMGA1 Proteins Accounts for the Reduced BRCA1 Protein Levels in Sporadic Breast Carcinoma

2003 ◽  
Vol 23 (7) ◽  
pp. 2225-2238 ◽  
Author(s):  
Gustavo Baldassarre ◽  
Sabrina Battista ◽  
Barbara Belletti ◽  
Sanjay Thakur ◽  
Francesca Pentimalli ◽  
...  
Keyword(s):  
Gene Expression ◽  
Breast Carcinoma ◽  
Es Cells ◽  
Embryonic Stem ◽  
Brca1 Gene ◽  
Brca1 Protein ◽  
Protein Levels ◽  
Sporadic Breast Carcinoma

ABSTRACT A drastic reduction in BRCA1 gene expression is a characteristic feature of aggressive sporadic breast carcinoma. However, the mechanisms underlying BRCA1 downregulation in breast cancer are not well understood. Here we report that both in vitro and in vivo HMGA1b protein binds to and inhibits the activity of both human and mouse BRCA1 promoters. Consistently, murine embryonic stem (ES) cells with the Hmga1 gene deleted display higher Brca1 mRNA and protein levels than do wild-type ES cells. Stable transfection of MCF-7 cells with the HMGA1b cDNA results in a decrease of BRCA1 gene expression and in a lack of BRCA1 induction after estrogen treatment. Finally, we found an inverse correlation between HMGA1 and BRCA1 mRNA and protein expression in human mammary carcinoma cell lines and tissues. These data indicate that HMGA1 proteins are involved in transcriptional regulation of the BRCA1 gene, and their overexpression may have a role in BRCA1 downregulation observed in aggressive mammary carcinomas.

scholarly journals Subnuclear localisation is associated with gene activation not repression or parental origin at the imprinted Dlk1-Dio3 locus

2021 ◽  
Author(s):  
Rahia Mashoodh ◽  
Lisa C Hulsmann ◽  
Frances L Dearden ◽  
Nozomi Takahashi ◽  
Anne C Ferguson-Smith
Keyword(s):  
Gene Expression ◽  
Transcriptional Repression ◽  
Es Cells ◽  
In Situ Hybridisation ◽  
Nuclear Periphery ◽  
Gene Activation ◽  
Three Dimensional ◽  
Embryonic Stem ◽  
Parental Origin ◽  
Fluorescence In Situ Hybridisation

At interphase, de-condensed chromosomes have a non-random three-dimensional architecture within the nucleus, however, little is known about the extent to which nuclear organisation might influence expression or vice versa. Here, using imprinting as a model, we use 3D RNA- and DNA-fluorescence-in-situ-hybridisation in normal and mutant mouse embryonic stem cells to assess the relationship between imprinting control, gene expression and allelic distance from the nuclear periphery. We compared the two parentally inherited imprinted domains at the Dlk1-Dio3 domain and find a small but reproducible trend for the maternally inherited domain to be further away from the periphery if the maternally expressed gene Gtl2/Meg3 is active compared to when it is silenced. Using Zfp57KO ES cells, which harbour a paternal to maternal epigenotype switch, we observe active alleles significantly further away from the nuclear periphery with the distance from the periphery being proportional to the number of alleles active within the cell. This distribution of alleles suggests an activating effect of the nuclear interior rather than a repressive association with the nuclear periphery. Although we see a trend for the paternally inherited copy of the locus to be closer to the nuclear periphery, this appears to be linked to stochastic gene expression differences rather than parental origin. Our results suggest that transcriptional activity, rather than transcriptional repression or parental origin, defines sub-nuclear localisation at an endogenous imprinted domain.

scholarly journals Dynamics of gene expression and chromatin marking during cell state transition

2020 ◽  
Author(s):  
Beatrice Borsari ◽  
Amaya Abad ◽  
Cecilia C. Klein ◽  
Ramil Nurtdinov ◽  
Alexandre Esteban ◽  
...  
Keyword(s):  
Gene Expression ◽  
Histone Modifications ◽  
State Transition ◽  
Strong Association ◽  
Gene Activation ◽  
Differentiation Process ◽  
Time Points ◽  
Initial Activation ◽  
Over Time

SummaryWe have monitored the transcriptomic and epigenomic status of cells at twelve time-points during the transdifferentiation of human pre-B cells into macrophages. Using this data, we have investigated some fundamental questions regarding the role of chromatin in gene expression. We have found that, over time, genes are characterized by a limited number of chromatin states (combinations of histone modifications), and that, consistently, chromatin changes over genes tend to occur in a coordinated manner. We have observed strong association between these changes and gene expression only at the time of initial gene activation. Activation is preceded by H3K4me1 and H3K4me2, and followed in a precise order by most other histone modifications. Further changes in gene expression, comparable or even stronger than those at initial activation, occur without associated changes in histone modifications. The data generated here constitutes, thus, a unique resource to investigate transcriptomic and epigenomic dynamics during a differentiation process.

scholarly journals Autoinduction of activin genes in early Xenopus embryos

1994 ◽  
Vol 298 (2) ◽  
pp. 275-280 ◽  
Author(s):  
A Suzuki ◽  
T Nagai ◽  
S I Nishimatsu ◽  
H Sugino ◽  
Y Eto ◽  
...  
Keyword(s):  
Gene Expression ◽  
Mrna Levels ◽  
Xenopus Embryos ◽  
Treatment Conditions ◽  
Dose Dependent Fashion ◽  
Polymerase Chain ◽  
Stage 1 ◽  
Dose Dependent

Activin exhibits a potent mesoderm inducing activity towards the ectodermal tissue (animal cap) of Xenopus laevis blastulae. Thus in order to investigate the role of activin in morphogenesis of early Xenopus embryos, activation of genes for activin beta A and beta B was examined by the reverse transcription polymerase chain reaction. In vivo, activin beta B mRNA appears to be present in embryonic stage 1 whereas beta A mRNA is undetectable prior to gastrulation. beta B and beta A mRNAs were noted to accumulate after stages 9 and 15 respectively. Activin gene expression in Xenopus animal caps was examined after treatment with various concentrations of activin A. Under these treatment conditions, both activin beta A and beta B mRNAs accumulated in a dose-dependent fashion after 24 h. The same effect was noted for treatment with similar concentrations of activin B. Accumulation of mRNAs was inhibited by the addition of cycloheximide to the culture medium, consistent with the proposition that activin gene expression requires certain protein factors. In total, therefore, these data suggest that an autoinduction mechanism is involved in the regulation of activin mRNA levels in normal Xenopus embryos and that this mechanism may play a pivotal role during early embryonic development.

Sign in / Sign up

Export Citation Format

Share Document