Pluripotency Associated Genes Are Reactivated by Chromatin‐Modifying Agents in Neurosphere Cells

@article{Ruau2008PluripotencyAG,
  title={Pluripotency Associated Genes Are Reactivated by Chromatin‐Modifying Agents in Neurosphere Cells},
  author={David Ruau and Roberto Ense{\~n}at-Waser and Timo C Dinger and Duttu S. Vallabhapurapu and Alexandra Rolletschek and Christine Hacker and Thomas Hieronymus and Anna M. Wobus and Albrecht M. Müller and Martin Zenke},
  journal={STEM CELLS},
  year={2008},
  volume={26}
}
Chromatin architecture in stem cells determines the pattern of gene expression and thereby cell identity and fate. The chromatin‐modifying agents trichostatin A (TSA) and 5‐Aza‐2′‐deoxycytidine (AzaC) affect histone acetylation and DNA methylation, respectively, and thereby influence chromatin structure and gene expression. In our previous work, we demonstrated that TSA/AzaC treatment of neurosphere cells induces hematopoietic activity in vivo that is long‐term, multilineage, and transplantable… 
Chromatin-modifying agents reactivate embryonic renal stem/progenitor genes in human adult kidney epithelial cells but abrogate dedifferentiation and stemness.
TLDR
VPA resulted in upregulation of E-CADHERIN and reduction in VIMENTIN, preventing the skewing of hKEpCs towards a more replicative mesenchymal state required for clonogenic expansion and acquisition of stem cell characters, altogether inducing cell senescence at early passages.
Inhibition of histone deacetylases by Trichostatin A leads to a HoxB4-independent increase of hematopoietic progenitor/stem cell frequencies as a result of selective survival.
TLDR
Chromatin-modifying agents may provide potential strategies for ex vivo expansion of HPSC and augmented histone acetylation achieved by transient Trichostatin A treatment increased the frequency of cells with H PSC immunophenotype and function in the heterogeneous pool of BM cells.
Epigenetic Modifiers Are Necessary but Not Sufficient for Reprogramming Non-Myelinating Cells into Myelin Gene-Expressing Cells
TLDR
The results suggest that reprogramming of fibroblasts into myelin gene-expressing cells not only requires transcriptional activation, but also chromatin manipulations that go beyond histone acetylation and DNA methylation.
Histone Deacetylase Inhibitors in Cell Pluripotency, Differentiation, and Reprogramming
TLDR
The molecular pathways that are involved in the functions of HDAC inhibitors on stem cell differentiation and reprogramming of somatic cells into pluripotency are reviewed.
The Polycomb Protein Ezh2 Impacts on Induced Pluripotent Stem Cell Generation
TLDR
Investigation of the impact of Ezh2, a core subunit of Polycomb repressive complex 2 (PRC2), on the generation of induced pluripotent stem (iPS) cells found that Ezh 2 expression is induced during iPS cell generation and iPS cells contain high levels of EzH2 mRNA and protein.
Epigenetic reprogramming modulates malignant properties of human liver cancer
TLDR
These results identify DNA methylation as a key epigenetic regulatory mechanism determining the pool of cancer stem cells in liver cancer and possibly other solid tumors.
The polycomb protein Ezh2 impacts on induced pluripotent stem cell generation.
TLDR
It is found that Ezh2 expression is induced during iPS cell generation and iPS cells contain high levels of Ezh1 mRNA and protein, whereas it is dispensable for maintaining the reprogrammed iPScell state.
Polycomb group protein Bmi1 promotes hematopoietic cell development from embryonic stem cells.
Bmi1 is a component of the Polycomb repressive complexes and essential for maintaining the pool of adult stem cells. Polycomb repressive complexes are key regulators for embryonic development by
Effect of dynamic DNA methylation and histone acetylation on cPouV expression in differentiation of chick embryonic germ cells.
TLDR
It is provided evidences that a critical role for cPouV activation/repression by DNA methylation and/or histone modifications is involved in the pluripotency maintenance and differentiation process of chick EG.
A Combined Epigenetic and Non-Genetic Approach for Reprogramming Human Somatic Cells
TLDR
Overall changes in methylation and acetylation levels of pretreated somatic cells suggests that epigenetic states of the cells have an effect on reprogramming efficiency induced by hESC extracts.
...
...

References

SHOWING 1-10 OF 47 REFERENCES
Polycomb complexes repress developmental regulators in murine embryonic stem cells
TLDR
It is shown that PcG proteins directly repress a large cohort of developmental regulators in murine ES cells, the expression of which would otherwise promote differentiation, and dynamic repression of developmental pathways by Polycomb complexes may be required for maintaining ES cell pluripotency and plasticity during embryonic development.
In vivo haematopoietic activity is induced in neurosphere cells by chromatin‐modifying agents
TLDR
The results indicate that altering the epigenotype of neurosphere cells followed by transplantation enables the generation of neuroSphere‐derived haematopoietic cells.
Modification of hematopoietic stem cell fate by 5aza 2'deoxycytidine and trichostatin A.
TLDR
5azaD and TSA can be used to alter the fate of primitive HSCs/HPCs during in vitro culture and retain the ability to repopulate immunodeficient mice, demonstrating that DNA methylation and histone deacetylation are components of an epigenetic program that regulates gene expression.
Synergy of demethylation and histone deacetylase inhibition in the re-expression of genes silenced in cancer
TLDR
Although DNA methylation and histone deacetylation appear to act as synergistic layers for the silencing of genes in cancer, dense CpG island methylation is dominant for the stable maintenance of a silent state at these loci.
The Oct4 and Nanog transcription network regulates pluripotency in mouse embryonic stem cells
TLDR
By integrating RNA interference–mediated depletion of Oct4 and Nanog with microarray expression profiling, it is demonstrated that these factors can activate or suppress transcription, and it is shown that common core downstream targets are important to keep ES cells from differentiating.
Aging Hematopoietic Stem Cells Decline in Function and Exhibit Epigenetic Dysregulation
TLDR
These studies show that hematopoietic stem cells are not protected from aging, and loss of epigenetic regulation at the chromatin level may drive both functional attenuation of cells, as well as other manifestations of aging, including the increased propensity for neoplastic transformation.
Hematopoietic competence is a rare property of neural stem cells that may depend on genetic and epigenetic alterations
TLDR
The results exclude hematopoietic competence as a consistent property of intravenously infused neural stem cells, but consistent changes that occurred during extended passaging are compatible with genetic or epigenetic alterations and suggest that rare transformation events may account for the neural-to-blood fate switch originally reported.
Changing potency by spontaneous fusion
TLDR
DNA contents per cell were determined by staining cells with propidium iodide and subsequent FACS analysis, and gene for the embryonic stem cell coactivator UTF1 carries a regulatory element which selectively interacts with a complex composed of Oct-3/4 and Sox-2.
Histone deacetylase inhibitors suppress IL-2-mediated gene expression prior to induction of apoptosis.
TLDR
Considering the biologic role played by IL-2-mediated gene expression in cell survival, these data suggest that its abrogation may contribute to the apoptotic process induced by HDAC inhibitors.
...
...