scholarly journals Differential regulation of lineage commitment in human and mouse primed pluripotent stem cells by NuRD

2020 ◽  
Author(s):  
Ramy Ragheb ◽  
Sarah Gharbi ◽  
Julie Cramard ◽  
Oluwaseun Ogundele ◽  
Susan Kloet ◽  
...  

AbstractDifferentiation of mammalian pluripotent cells involves large-scale changes in transcription and, among the molecules that orchestrate these changes, chromatin remodellers are essential to initiate, establish and maintain a new gene regulatory network. The NuRD complex is a highly conserved chromatin remodeller which fine-tunes gene expression in embryonic stem cells. While the function of NuRD in mouse pluripotent cells has been well defined, no study yet has defined NuRD function in human pluripotent cells. We investigated the structure and function of NuRD in human induced pluripotent stem cells (hiPSCs). Using immunoprecipitation followed by mass-spectrometry in hiPSCs and in naive or primed mouse pluripotent stem cells, we find that NuRD structure and biochemical interactors are generally conserved. Using RNA sequencing, we find that, whereas in mouse primed stem cells and in mouse naïve ES cells, NuRD is required for an appropriate level of transcriptional response to differentiation signals, hiPSCs require NuRD to initiate these responses. This difference indicates that mouse and human cells interpret and respond to induction of differentiation differently.Graphical AbstractNuRD acts like a conductor in an orchestra.A. In the presence of NuRD (pink blob figure, centre) differentiation occurs in an ordered fashion in both mouse (left) and human (right) ES cells. Gene expression changes in both cell types are tightly controlled with down-regulation of pluripotency genes and up-regulation of lineage appropriate genes. This is akin to a group of musicians producing musical notes in the right order and at the right amplitude to create a coherent piece of music. B. Loss of “the conductor” NuRD results in increased transcriptional noise in both systems, indicated here as a low-level blanket of sound in both systems. Consequences of MBD3/NuRD loss differs between human and mouse ES cells. In mouse ES cells, differentiation cues lead to some down-regulation of pluripotency genes and incomplete progression along a lineage appropriate pathway. This is like musicians who know that they should be making music but who lose their way without a conductor’s influence. In human iPS cells the background level of noise without NuRD results in a lack of order to gene expression changes in response to differentiation. The noise from these “musicians” would be truly awful.

2012 ◽  
Vol 24 (1) ◽  
pp. 286
Author(s):  
A. Dinnyes ◽  
M. K. Pirity ◽  
E. Gocza ◽  
P. Osteil ◽  
N. Daniel ◽  
...  

Pluripotent stem cells have the capacity to divide indefinitely and to differentiate to all the somatic tissues. They can be genetically manipulated in vitro by knocking in and out genes, therefore they serve as an excellent tool for gene-function studies and for the generation of models for human diseases. Since 1981, when the first mouse embryonic stem cell (ESC) line was generated, several attempts have been made to generate pluripotent stem cells from other species as it would help us to understand the differences and similarities of signaling pathways involved in pluripotency and differentiation, and would reveal whether the fundamental mechanism controlling self-renewal of pluripotent cells is conserved among different species. This review gives an overlook of embryonic and induced pluripotent stem cell (iPSCs) research in the rabbit which is one of the most relevant non-rodent species for animal models. To date, several lines of putative ESCs and iPSCs have been described in the rabbit. All expressed stem cell-associated markers and exhibited longevity and pluripotency in vitro, but none have been proven to exhibit full pluripotency in vivo. Moreover, similarly to several domestic species, markers used to characterize the putative ESCs are not fully adequate because studies in domestic species have revealed that they are not specific to the pluripotent inner cell mass. Future validation of rabbit pluripotent stem cells would benefit greatly from a reliable panel of molecular markers specific to pluripotent cells of the developing rabbit embryo. The status of isolation and characterization of the putative pluripotency genes in rabbit will be discussed. Using rabbit specific pluripotency genes we might be able to reprogram somatic cells and generate induced pluripotent stem cells more efficiently thus overcome some of the challenges towards harnessing the potential of this technology. This study was financed by EU FP7 (PartnErS, PIAP-GA-2008-218205; InduHeart, PEOPLE-IRG-2008-234390; InduVir, PEOPLE-IRG-2009-245808; RabPstem, PERG07-GA-2010-268422; PluriSys, HEALTH-2007-B-223485; AniStem, PIAP-GA-2011-286264), NKTH-OTKA-EU-7KP HUMAN-MB08-C-80-205; Plurabbit, OMFB-00130-00131/2010 ANR-NKTH/09-GENM-010-01.


eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Rosa María Marión ◽  
Juan J Montero ◽  
Isabel López de Silanes ◽  
Osvaldo Graña-Castro ◽  
Paula Martínez ◽  
...  

The mechanisms that regulate pluripotency are still largely unknown. Here, we show that Telomere Repeat Binding Factor 1 (TRF1), a component of the shelterin complex, regulates the genome-wide binding of polycomb and polycomb H3K27me3 repressive marks to pluripotency genes, thereby exerting vast epigenetic changes that contribute to the maintenance of mouse ES cells in a naïve state. We further show that TRF1 mediates these effects by regulating TERRA, the lncRNAs transcribed from telomeres. We find that TERRAs are enriched at polycomb and stem cell genes in pluripotent cells and that TRF1 abrogation results in increased TERRA levels and in higher TERRA binding to those genes, coincidental with the induction of cell-fate programs and the loss of the naïve state. These results are consistent with a model in which TRF1-dependent changes in TERRA levels modulate polycomb recruitment to pluripotency and differentiation genes. These unprecedented findings explain why TRF1 is essential for the induction and maintenance of pluripotency.


2019 ◽  
Vol 14 (3) ◽  
pp. 278-289 ◽  
Author(s):  
Maryam Farzaneh ◽  
Masoumeh Alishahi ◽  
Zahra Derakhshan ◽  
Neda H. Sarani ◽  
Farnoosh Attari ◽  
...  

The discovery of small non-coding RNAs began an interesting era in cellular and molecular biology. To date, miRNAs are the best recognized non-coding RNAs for maintenance and differentiation of pluripotent stem cells including embryonic stem cells (ES), induced pluripotent stem cells (iPSC), and cancer stem cells. ES cells are defined by their ability to self-renew, teratoma formation, and to produce numerous types of differentiated cells. Dual capacity of ES cells for self-renewal and differentiation is controlled by specific interaction with the neighboring cells and intrinsic signaling pathways from the level of transcription to translation. The ES cells have been the suitable model for evaluating the function of non-coding RNAs and in specific miRNAs. So far, the general function of the miRNAs in ES cells has been assessed in mammalian and non-mammalian stem cells. Nowadays, the evolution of sequencing technology led to the discovery of numerous miRNAs in human and mouse ES cells that their expression levels significantly changes during proliferation and differentiation. Several miRNAs have been identified in ectoderm, mesoderm, and endoderm cells, as well. This review would focus on recent knowledge about the expression and functional roles of miRNAs in embryonic and lineage-specific stem cells. It also describes that miRNAs might have essential roles in orchestrating the Waddington's landscape structure during development.


2017 ◽  
Author(s):  
Ralph Stadhouders ◽  
Enrique Vidal ◽  
François Serra ◽  
Bruno Di Stefano ◽  
François Le Dily ◽  
...  

ABSTRACTChromosomal architecture is known to influence gene expression, yet its role in controlling cell fate remains poorly understood. Reprogramming of somatic cells into pluripotent stem cells by the transcription factors (TFs) Oct4, Sox2, Klf4 and Myc offers an opportunity to address this question but is severely limited by the low proportion of responding cells. We recently developed a highly efficient reprogramming protocol that synchronously converts somatic into pluripotent stem cells. Here, we employ this system to integrate time-resolved changes in genome topology with gene expression, TF binding and chromatin state dynamics. This revealed that TFs drive topological genome reorganization at multiple architectural levels, which often precedes changes in gene expression. Removal of locus-specific topological barriers can explain why pluripotency genes are activated sequentially, instead of simultaneously, during reprogramming. Taken together, our study implicates genome topology as an instructive force for implementing transcriptional programs and cell fate in mammals.


2020 ◽  
Vol 46 (Supplement_1) ◽  
pp. S234-S234
Author(s):  
Lorna Farrelly ◽  
Shuangping Zhang ◽  
Erin Flaherty ◽  
Aaron Topol ◽  
Nadine Schrode ◽  
...  

Abstract Background Schizophrenia (SCZ) is a severe psychiatric disorder affecting ~1% of the world’s population. It is largely heritable with genetic risk reflected by a combination of common variants of small effect and highly penetrant rare mutations. Chromatin modifications are known to play critical roles in the mediation of many neurodevelopmental processes, and, when disturbed, may also contribute to the precipitation of psychiatric disorders, such as SCZ. While a handful of candidate-based studies have measured changes in promoter-bound histone modifications, few mechanistic studies have been carried out to explore how these modifications may affect chromatin to precipitate behavioral phenotypes associated with the disease. Methods We applied an unbiased proteomics approach to evaluate the epigenetic landscape of SCZ in human induced pluripotent stem cells (hiPSC), neural progenitor cells (NPCs) and neurons from SCZ patients vs. matched controls. We utilized proteomics-based, label free liquid chromatography mass spectrometry (LC-MS/MS) on purified histones from these cells and confirmed our results by western blotting in postmortem SCZ cortical brain tissues. Furthermore we validated our findings with the application of histone interaction assays and structural and biophysical assessments to identify and confirm novel chromatin ‘readers’. To relate our findings to a SCZ phenotype we used a SCZ rodent model of prepulse inhibition (PPI) to perform pharmacological manipulations and behavioral assessments. Results Using label free mass spectrometry we performed PTM screening of hiPSCs, NPCs and matured neurons derived from SCZ patients and matched controls. We identified, amongst others, altered patterns of hyperacetylation in SCZ neurons. Additionally we identified enhanced binding of particular acetylation ‘reader’ proteins. Pharmacological inhibition of such proteins in an animal model of amphetamine sensitization ameliorated PPI deficits further validating this epigenetic signature in SCZ. Discussion Recent evidence indicates that relevance and patterns of acetylation in epigenetics advances beyond its role in transcription and small molecule inhibitors of these aberrant interactions hold promise as useful therapeutics. This study identifies a role for modulating gene expression changes associated with a SCZ epigenetic signature and warrants further investigation in terms of how this early gene expression pattern perhaps determines susceptibility or severity of the SCZ disease trajectory.


2015 ◽  
Vol 47 (6) ◽  
pp. 232-239 ◽  
Author(s):  
Gustav Holmgren ◽  
Nidal Ghosheh ◽  
Xianmin Zeng ◽  
Yalda Bogestål ◽  
Peter Sartipy ◽  
...  

Reference genes, often referred to as housekeeping genes (HKGs), are frequently used to normalize gene expression data based on the assumption that they are expressed at a constant level in the cells. However, several studies have shown that there may be a large variability in the gene expression levels of HKGs in various cell types. In a previous study, employing human embryonic stem cells (hESCs) subjected to spontaneous differentiation, we observed that the expression of commonly used HKG varied to a degree that rendered them inappropriate to use as reference genes under those experimental settings. Here we present a substantially extended study of the HKG signature in human pluripotent stem cells (hPSC), including nine global gene expression datasets from both hESC and human induced pluripotent stem cells, obtained during directed differentiation toward endoderm-, mesoderm-, and ectoderm derivatives. Sets of stably expressed genes were compiled, and a handful of genes (e.g., EID2, ZNF324B, CAPN10, and RABEP2) were identified as generally applicable reference genes in hPSCs across all cell lines and experimental conditions. The stability in gene expression profiles was confirmed by reverse transcription quantitative PCR analysis. Taken together, the current results suggest that differentiating hPSCs have a distinct HKG signature, which in some aspects is different from somatic cell types, and underscore the necessity to validate the stability of reference genes under the actual experimental setup used. In addition, the novel putative HKGs identified in this study can preferentially be used for normalization of gene expression data obtained from differentiating hPSCs.


2020 ◽  
Author(s):  
A Andrianto ◽  
Adityo Basworo ◽  
Ivana Purnama Dewi ◽  
Budi Susetio Pikir

IntroductionIt is possible to induce pluripotent stem cells from somatic cells, offering an infinite cell resource with the potential for disease research and use in regenerative medicine. Due to ease of accessibility, minimum invasive treatment, and can be kept frozen, peripheral blood mononuclear cells (PBMC) were an attractive source cell. VC6TFZ, a small molecule compound, has been successfully reprogrammed from mouse fibroblast induced pluripotent stem cells (iPSCs). However, it has not been confirmed in humans.ObjectiveThe aim of this research is to determine whether the small molecule compound VC6TFZ can induced pluripotency of PBMC to generate iPSCs detected with expression of SSEA4 and TRA1-60.MethodsUsing the centrifugation gradient density process, mononuclear cells were separated from peripheral venous blood. Mononuclear cells were cultured for 6 days in the expansion medium. The cells were divided into four groups; group 1 (P1), which was not exposed to small molecules (control group) and groups 2-4 (P2-P4), the experimental groups, subjected to various dosages of the small molecule compound VC6TFZ (VPA, CHIR, Tranylcypromine, FSK, Dznep, and TTNPB). The induction of pluripotency using small molecule compound VC6TFZ was completed within 14 days, then for 7 days the medium shifted to 2i medium. iPSCs identification in based on colony morphology and pluripotent gene expression, SSEA4 and TRA1-60 marker, using immunocytochemistry.ResultsColonies appeared on reprogramming process in day 7th. These colonies had round, large, and cobble stone morphology like ESC. Gene expression of SSEA4 and TRA 1-60 increased statisticaly significant than control group (SSEA4 were P2 p=0.007; P3 p=0.001; P4 p=0.009 and TRA 1-60 were P2 p=0.002; P3 p=0.001; P4 p=0.001).ConclusionSmall molecule compound VC6TFZ could induced pluripotency of human PBMC to generate iPSCs. Pluripotxency marker gene expression, SSEA 4 and TRA 1-60, in the experimental group was statistically significantly higher than in the control group.


2000 ◽  
Vol 113 (1) ◽  
pp. 5-10 ◽  
Author(s):  
M.F. Pera ◽  
B. Reubinoff ◽  
A. Trounson

Embryonic stem (ES) cells are cells derived from the early embryo that can be propagated indefinitely in the primitive undifferentiated state while remaining pluripotent; they share these properties with embryonic germ (EG) cells. Candidate ES and EG cell lines from the human blastocyst and embryonic gonad can differentiate into multiple types of somatic cell. The phenotype of the blastocyst-derived cell lines is very similar to that of monkey ES cells and pluripotent human embryonal carcinoma cells, but differs from that of mouse ES cells or the human germ-cell-derived stem cells. Although our understanding of the control of growth and differentiation of human ES cells is quite limited, it is clear that the development of these cell lines will have a widespread impact on biomedical research.


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