Suppression of the PI3K subunit p85α delays embryoid body development and inhibits cell adhesion

2011 ◽  
Vol 112 (12) ◽  
pp. 3573-3581 ◽  
Author(s):  
Susan M.R. Gurney ◽  
Peter Forster ◽  
Ursula Just ◽  
Ralf Schwanbeck
Keyword(s):  
Cell Adhesion ◽  
Embryoid Body ◽  
Body Development

Altered Regulation of β like Globin Genes by a Redesigned Erythroid Transcription Factor.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1212-1212
Author(s):  
Deepa Manwani ◽  
Mariann Galdass ◽  
James J. Bieker
Keyword(s):  
Transcription Factor ◽  
Transcription Factors ◽  
Zinc Finger ◽  
Embryoid Body ◽  
Globin Gene ◽  
Beta Globin ◽  
Erythroid Cells ◽  
Beta Globin Gene ◽  
Body Development ◽  
Globin Promoter

Abstract The well characterized switch during ontogeny of globin gene expression from embryonic/ fetal to adult type is a result of a complex interplay between cis and trans acting regulatory elements at the beta globin locus. Trans acting elements include tissue specific transcription factors that bind specific motifs within the beta globin gene cluster with high specificity. Erythroid Kruppel like factor (EKLF) is one such erythroid specific, zinc finger transcription factor that is critical for the activation of the beta globin promoter and for consolidating the switch from gamma to beta globin during development. The ability to willfully regulate the expression of endogenous genes using redesigned zinc finger transcription factors is an emerging field. There is tremendous appeal in utilizing the understanding of transcriptional control pathways to design tools that will elucidate molecular mechanisms and provide potential therapeutic tools. To this end we redesigned Erythroid Kruppel Like Factor (EKLF) as a transcriptional repressor. The zinc finger DNA binding domain was linked to the repressor domain from the Drosophila Engrailed protein with the prediction that this construct (ENG/ZNF) would bind the beta globin promoter and repress it. It was hypothesized that embryonic/fetal globin activation would result by a competitive mechanism. When introduced transiently into cells these transcription factors are effective in repressing the adult beta globin promoter CACCC element, the natural target for EKLF. In stable MEL clones, repression of the adult beta globin gene is accompanied by a reactivation of the endogenous embryonic globin gene. In order to study this effect in the context of a whole animal we generated transgenic mice expressing ENG/ZNF. A 271 bp region 5′of the ANK-1 gene was chosen to drive expression in transgenic mice as it provides erythroid specific expression with copy number dependence and minimal position dependence. D13.5 fetal livers were subject to RT-PCR analysis in the linear range to quantitate the ratios of BH1 to alpha globin transcripts. The 9 ENG/ZNF transgenic embryos express BH1 mRNa in a range of values that is statistically higher than in 9 control littermates (Mann Whitney U test, p value 0.02) and beta major globin mRNA at lower levels. We further studied ENG/ZNF in the developmentally plastic environment of differentiating murine embryonic stem cells. The construct was stably integrated into a targeting site upstream of the HPRT locus under the control of a tetracycline inducible promoter. The Doxycycline induction of ENG/ZNF transgene expression results in a 4 fold activation of embryonic globin at day 6 of embryoid body development; however there is no evidence of beta globin repression. Since at this stage of embryoid body development, primitive erythroid cells are 100–500 fold more abundant than definitive erythroid cells, this may reflect a differential effect of EKLF in primitive erythroid cells. To evaluate this further, we are currently performing analyses in primitive versus definitive erythroid colonies. In conclusion, our studies support the competitive model of globin switching and may contribute to the delineation of a stage specific role of EKLF. In addition, transcriptional reagents that augment gamma globin expression hold promise as novel therapeutic agents for sickle cell disease and other hemoglobinopathies.

Tyrosine phosphatase SHP-1 acts at different stages of development to regulate hematopoiesis

Blood ◽  
2005 ◽  
Vol 105 (11) ◽  
pp. 4290-4297 ◽  
Author(s):  
Nicholas R. D. Paling ◽  
Melanie J. Welham
Keyword(s):  
Embryoid Body ◽  
Es Cells ◽  
Tyrosine Phosphatase ◽  
Embryonic Stem ◽  
Embryoid Bodies ◽  
Dominant Negative ◽  
Body Development ◽  
Undifferentiated Cells ◽  
Hematopoietic Precursor ◽  
Multiple Stages

Abstract Mice lacking SHP-1 exhibit a plethora of perturbations in their hematopoietic and immune systems. To reveal the primary effects resulting from SHP-1 deficiency, we used embryonic stem (ES) cells to study the role of SHP-1 in developmental hematopoiesis. We expressed wild-type (WT) and dominant-negative (R459M) forms of SHP-1 in ES cells and used ES/OP-9 coculture and embryoid body development followed by hematopoietic colony assays to demonstrate that SHP-1 acts at multiple stages of hematopoietic differentiation to alter lineage balance. Expression of WT SHP-1 reduced myeloid colony numbers while increasing the numbers of secondary embryoid bodies and mixed hematopoietic colonies obtained. Conversely, expression of R459M SHP-1 resulted in a significant increase in the numbers and sizes of myeloid colonies observed while reducing the numbers of colonies derived from undifferentiated cells or hematopoietic precursor cells. Confining the expression of WT or R459M SHP-1 to the early phases of differentiation decreased and increased progenitor cell numbers, respectively, and influenced colony formation. Overall, our results are consistent with SHP-1 acting during multiple stages of hematopoietic development, and they suggest that the increases in granulocytes and macrophages observed in motheaten mice arise as the result of a cell autonomous effect early during development.

scholarly journals Modelling human embryoid body cell adhesion to a combinatorial library of polymer surfaces

2012 ◽  
Vol 22 (39) ◽  
pp. 20902 ◽  
Author(s):  
V. Chandana Epa ◽  
Jing Yang ◽  
Ying Mei ◽  
Andrew L. Hook ◽  
Robert Langer ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Combinatorial Library ◽  
Embryoid Body ◽  
Polymer Surfaces ◽  
Body Cell

A common precursor for hematopoietic and endothelial cells

Development ◽  
1998 ◽  
Vol 125 (4) ◽  
pp. 725-732 ◽  
Author(s):  
K. Choi ◽  
M. Kennedy ◽  
A. Kazarov ◽  
J.C. Papadimitriou ◽  
G. Keller
Keyword(s):  
Embryoid Body ◽  
Embryonic Stem ◽  
Embryoid Bodies ◽  
Vascular Endothelial ◽  
Body Development ◽  
Common Precursor ◽  
Colony Forming Cell ◽  
Semi Solid ◽  
Endothelial Growth Factor ◽  
Endothelial Precursors

Embryonic stem cell-derived embryoid bodies contain a unique precursor population which, in response to vascular endothelial growth factor, gives rise to blast colonies in semi-solid medium. Upon transfer to liquid culture with appropriate cytokines, these blast colonies generate both hematopoietic and adherent, stromal-type cells. Cells within the adherent population display characteristics of endothelial lineage including the expression of CD31, flk-1, flt-1, tie-2, the capacity to take up acetylated LDL and the presence of cytoplasmic Weibel-Palade bodies. Mixing studies demonstrated that the hematopoietic and endothelial precursors within the blast colonies develop from the same cell, the blast colony-forming cell. Kinetic analysis showed that the blast colony-forming cell represents a transient cell population that develops early and is lost quickly during embryoid body development. These findings provide strong evidence that the blast colony-forming cell represents the long-hypothesized hemangioblast, the common precursor of the hematopoietic and endothelial lineages.

scholarly journals High resolution temporal transcriptomics of mouse embryoid body development reveals complex expression dynamics of coding and noncoding loci

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Brian S. Gloss ◽  
Bethany Signal ◽  
Seth W. Cheetham ◽  
Franziska Gruhl ◽  
Dominik C. Kaczorowski ◽  
...  
Keyword(s):  
High Resolution ◽  
Embryoid Body ◽  
Body Development ◽  
Complex Expression

scholarly journals Effect of endoglin overexpression during embryoid body development

2012 ◽  
Vol 40 (10) ◽  
pp. 837-846 ◽  
Author(s):  
June Baik ◽  
Luciene Borges ◽  
Alessandro Magli ◽  
Tayaramma Thatava ◽  
Rita C.R. Perlingeiro
Keyword(s):  
Embryoid Body ◽  
Body Development

scholarly journals Loss of heme oxygenase-1 accelerates mesodermal gene expressions during embryoid body development from mouse embryonic stem cells

Redox Biology ◽  
2018 ◽  
Vol 15 ◽  
pp. 51-61 ◽  
Author(s):  
Yan-Liang Lai ◽  
Chen-Yu Lin ◽  
Wei-Cheng Jiang ◽  
Yen-Chun Ho ◽  
Chung-Huang Chen ◽  
...  
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Heme Oxygenase ◽  
Embryoid Body ◽  
Embryonic Stem ◽  
Mouse Embryonic Stem Cells ◽  
Heme Oxygenase 1 ◽  
Gene Expressions ◽  
Body Development
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