scholarly journals Neural Differentiation Is Inhibited through HIF1α/β-Catenin Signaling in Embryoid Bodies

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Josef Večeřa ◽  
Jana Kudová ◽  
Jan Kučera ◽  
Lukáš Kubala ◽  
Jiří Pacherník

Extensive research in the field of stem cells and developmental biology has revealed evidence of the role of hypoxia as an important factor regulating self-renewal and differentiation. However, comprehensive information about the exact hypoxia-mediated regulatory mechanism of stem cell fate during early embryonic development is still missing. Using a model of embryoid bodies (EBs) derived from murine embryonic stem cells (ESC), we here tried to encrypt the role of hypoxia-inducible factor 1α (HIF1α) in neural fate during spontaneous differentiation. EBs derived from ESC with the ablated gene for HIF1α had abnormally increased neuronal characteristics during differentiation. An increased neural phenotype in Hif1α−/− EBs was accompanied by the disruption of β-catenin signaling together with the increased cytoplasmic degradation of β-catenin. The knock-in of Hif1α, as well as β-catenin ectopic overexpression in Hif1α−/− EBs, induced a reduction in neural markers to the levels observed in wild-type EBs. Interestingly, direct interaction between HIF1α and β-catenin was demonstrated by immunoprecipitation analysis of the nuclear fraction of wild-type EBs. Together, these results emphasize the regulatory role of HIF1α in β-catenin stabilization during spontaneous differentiation, which seems to be a crucial mechanism for the natural inhibition of premature neural differentiation.

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Gergo Kovacs ◽  
Viktoria Szabo ◽  
Melinda K. Pirity

Rybp (Ring1 and Yy1 Binding Protein) is a transcriptional regulator and member of the noncanonical polycomb repressive complex 1 with essential role in early embryonic development. We have previously described that alteration of Rybp dosage in mouse models induced striking neural tube defects (NTDs), exencephaly, and disorganized neurocortex. In this study we further investigated the role of Rybp in neural differentiation by utilising wild type (rybp+/+) andrybp nullmutant (rybp-/-) embryonic stem cells (ESCs) and tried to uncover underlying molecular events that are responsible for the observed phenotypic changes. We found thatrybp nullmutant ESCs formed less matured neurons, astrocytes, and oligodendrocytes from existing progenitors than wild type cells. Furthermore, lack ofrybpcoincided with altered gene expression of key neural markers including Pax6 and Plagl1 pinpointing a possible transcriptional circuit among these genes.


2008 ◽  
Vol 20 (9) ◽  
pp. 111
Author(s):  
J. C. Young ◽  
Y. Miyamoto ◽  
A. Major ◽  
V. L. Dias ◽  
D. A. Jans ◽  
...  

The importin (IMP) family of proteins mediates transport into the nucleus for many proteins larger than 40 kD. Through differential cargo recognition, IMPs regulate cellular events by controlling nuclear access of transcription factors and chromatin remodelling agents. During spermatogenesis, many IMPs change expression and localisation in a manner concordant with specific stages of spermatogenic development. To assess the potential role of IMPs in the transition between the stem cell and subsequent differentiation, we undertook analysis of the expression and subcellular localisation of several key murine IMPs in both pluripotent embryonic stem cells (mESCs) and embryoid bodies (EBs). All of the IMPs analysed (IMPα2, 3, 4, IMPβ1 and IMP5) were detected in undifferentiated mESCs by immunofluorescence, and each exhibited distinctive nucleocytoplasmic distribution patterns. Subcellular localisation of most IMPs altered after 10 days of mESC differentiation as EBs. This was paralleled by changes in the mRNA levels of IMPα1–4, IMPα6, IMPβ1 and IMP5, concomitant with alterations in the expression level of the pluripotency marker, Oct3/4. Reducing IMP-dependent nuclear import through overexpression of specific dominant-negative IMP constructs led to alterations in import or production of Oct3/4 protein, depending on the specific IMP. These findings indicate that IMPs may play very specific but distinct roles in cell fate choice between maintenance of pluri/multipotency and commitment to differentiation in ESCs and potentially in spermatogenesis or other organs that contain stem cells.


2021 ◽  
Author(s):  
Candice Byers ◽  
Catrina Spruce ◽  
Haley J. Fortin ◽  
Anne Czechanski ◽  
Steven C. Munger ◽  
...  

AbstractGenetically diverse pluripotent stem cells (PSCs) display varied, heritable responses to differentiation cues in the culture environment. By harnessing these disparities through derivation of embryonic stem cells (ESCs) from the BXD mouse genetic reference panel, along with C57BL/6J (B6) and DBA/2J (D2) parental strains, we demonstrate genetically determined biases in lineage commitment and identify major regulators of the pluripotency epigenome. Upon transition to formative pluripotency using epiblast-like cells (EpiLCs), B6 quickly dissolves naïve networks adopting gene expression modules indicative of neuroectoderm lineages; whereas D2 retains aspects of naïve pluripotency with little bias in differentiation. Genetic mapping identifies 6 major trans-acting loci co-regulating chromatin accessibility and gene expression in ESCs and EpiLCs, indicating a common regulatory system impacting cell state transition. These loci distally modulate occupancy of pluripotency factors, including TRIM28, P300, and POU5F1, at hundreds of regulatory elements. One trans-acting locus on Chr 12 primarily impacts chromatin accessibility in ESCs; while in EpiLCs the same locus subsequently influences gene expression, suggesting early chromatin priming. Consequently, the distal gene targets of this locus are enriched for neurogenesis genes and were more highly expressed when cells carried B6 haplotypes at this Chr 12 locus, supporting genetic regulation of biases in cell fate. Spontaneous formation of embryoid bodies validated this with B6 showing a propensity towards neuroectoderm differentiation and D2 towards definitive endoderm, confirming the fundamental importance of genetic variation influencing cell fate decisions.


Cell Calcium ◽  
2016 ◽  
Vol 59 (2-3) ◽  
pp. 67-74 ◽  
Author(s):  
Baixia Hao ◽  
Sarah E. Webb ◽  
Andrew L. Miller ◽  
Jianbo Yue

2001 ◽  
Vol 114 (5) ◽  
pp. 931-939 ◽  
Author(s):  
P. Murray ◽  
D. Edgar

Both the extracellular matrix and parathyroid hormone-related peptide (PTHrP) have been implicated in the differentiation and migration of extra-embryonic endodermal cells in the pre-implantation mammalian blastocyst. In order to define the individual roles and interactions between these factors in endodermal differentiation, we have used embryoid bodies derived from Lamc1(-/-) embryonic stem cells that lack basement membranes. The results show that in the absence of basement membranes, increased numbers of both visceral and parietal endodermal cells differentiate, but they fail to form organised epithelia. Furthermore, although parietal endodermal cells only migrate away from control embryoid bodies in the presence of PTHrP, they readily migrate from Lamc1(-/-) embryoid bodies in the absence of PTHrP, and this migration is unaffected by PTHrP. Thus, the basement membrane between epiblast and extra-embryonic endoderm is required for the proper organisation of visceral and parietal endodermal cells and also restricts their differentiation to maintain the population of primitive endodermal stem cells. Moreover, this basement membrane inhibits migration of parietal endodermal cells, the role of PTHrP being to stimulate delamination of parietal endodermal cells from the basement membrane rather than promoting migration per se.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Weiwei Sun ◽  
Bin Zhang ◽  
Qingli Bie ◽  
Na Ma ◽  
Na Liu ◽  
...  

The biological role of RNA methylation in stem cells has attracted increasing attention. Recent studies have demonstrated that RNA methylation plays a crucial role in self-renewal, differentiation, and tumorigenicity of stem cells. In this review, we focus on the biological role of RNA methylation modifications including N6-methyladenosine, 5-methylcytosine, and uridylation in embryonic stem cells, adult stem cells, induced pluripotent stem cells, and cancer stem cells, so as to provide new insights into the potential innovative treatments of cancer or other complex diseases.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 4157-4157
Author(s):  
Anand S. Srivastava ◽  
Rangrath Mishra ◽  
Ewa Carrier

Abstract Recently, it was demonstrated that TPO enhances hematopoietic differentiation of primate ES cells, but its role in differentiating human ES cells is unknown. We sought to investigate the regulatory mechanism of TPO induced signals mediated by the c-mpl cytoplasmic domain during human embryonic stem (hES) cells hematopoietic commitment. We hypothesize that in human embryonic stem cells, binding of TPO to its c-mpl receptor causes three-dimensional alterations which bring the c-mpl cytoplasmic domain and Janus Kinase into close-proximity and thus induces the phosphorylation and dimerization of STAT5 molecule. Dimerized STAT5 molecules detach from the receptors and migrate to the nucleus where they bind GAS site and induce transcription of a set of target, hematopoiesis-related genes. NIH human ES cell lines (WI01) were used in this experiment. In brief, to induce EB formation, cells were incubated in differentiation medium, which consisted of knockout DMEM medium (GIBCO/BRL, Carlsbad, USA), supplemented with 20% non-heat-inactivated fetal bovine serum (FBS, Hyclone, USA), 1% nonessential amino acids, 1 mM L-glutamine, and 0.1 mM β-mercaptoethanol. Subsequently, DMEM was replaced by IMDM (GIBCO/BRL, USA) with the same supplements and additional two cytokines (100 ng/mL SCF and 100 ng/mL Flt-3 ligand (Flt-3L)) (control group). To investigate the role of TPO and VEGF, cells were additionally treated with 100 ng/mL TPO alone or in combination with 100 ng/mL rhVEGF. All cytokines were from the R&D systems (USA). Significant increase in the numbers of embryoid bodies (EBs) formation in TPO (125/105), TPO/VEGF (150/105 cells) when compared to controls (10/105 planted ES cells) was documented. This corresponded with the increase in CFU-C and the number of CD31/CD34 positive and CD34-positive progenitors. Analysis of gene expression during hematopoietic development demonstrated that TPO/VEGF combination increased mRNA expression of the TPO receptor (TPO-R) and VEGF (VEGF-R) receptors in hematopoietic progenitors obtained from human ES cells. We are in the process of determining the role of JAK/STAT pathway in this process; functional studies involve blocking of TPO/c-mpl using TPO-R-specific antibodies and determining its impact on human ES-derived hematopoiesis.


EMBO Reports ◽  
2014 ◽  
Vol 16 (1) ◽  
pp. 63-70 ◽  
Author(s):  
Luigi Aloia ◽  
Arantxa Gutierrez ◽  
Juan Martin Caballero ◽  
Luciano Di Croce

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