scholarly journals SUMO maintains the chromatin environment of human induced pluripotent stem cells

2020 ◽  
Author(s):  
Barbara Mojsa ◽  
Michael H. Tatham ◽  
Lindsay Davidson ◽  
Magda Liczmanska ◽  
Jane E. Wright ◽  
...  
Keyword(s):  
Stem Cells ◽  
Induced Pluripotent Stem Cells ◽  
Cell Fate ◽  
Pluripotent Stem Cells ◽  
Transcriptional Start Site ◽  
Chromatin Accessibility ◽  
Covalent Attachment ◽  
Cell Fate Decisions ◽  
Sumo Modification ◽  
Induced Pluripotent

AbstractPluripotent stem cells represent a powerful system to identify the mechanisms governing cell fate decisions during early mammalian development. Covalent attachment of the Small Ubiquitin Like Modifier (SUMO) to proteins has emerged as an important factor in stem cell maintenance. Here we show that SUMO is required to maintain stem cells in their pluripotent state and identify many chromatin-associated proteins as bona fide SUMO substrates in human induced pluripotent stem cells (hiPSCs). Loss of SUMO increases chromatin accessibility and expression of long non-coding RNAs and human endogenous retroviral elements, indicating a role for the SUMO modification of SETDB1 and a large TRIM28 centric network of zinc finger proteins in silencing of these elements. While most protein coding genes are unaffected, the Preferentially Expressed Antigen of Melanoma (PRAME) gene locus becomes more accessible and transcription is dramatically increased after inhibition of SUMO modification. When PRAME is silent, a peak of SUMO over the transcriptional start site overlaps with ChIP-seq peaks for cohesin, RNA pol II, CTCF and ZNF143, with the latter two heavily modified by SUMO. These associations suggest that silencing of the PRAME gene is maintained by the influence of SUMO on higher order chromatin structure. Our data indicate that SUMO modification plays an important role in hiPSCs by repressing genes that disrupt pluripotency networks or drive differentiation.

Signaling Pathways Controlling Pluripotency and Early Cell Fate Decisions of Human Induced Pluripotent Stem Cells

Stem Cells ◽  
2009 ◽  
Vol 27 (11) ◽  
pp. 2655-2666 ◽  
Author(s):  
Ludovic Vallier ◽  
Thomas Touboul ◽  
Stephanie Brown ◽  
Candy Cho ◽  
Bilada Bilican ◽  
...  
Keyword(s):  
Stem Cells ◽  
Induced Pluripotent Stem Cells ◽  
Signaling Pathways ◽  
Cell Fate ◽  
Pluripotent Stem Cells ◽  
Cell Fate Decisions ◽  
Induced Pluripotent

scholarly journals Research and therapy with induced pluripotent stem cells (iPSCs): social, legal, and ethical considerations

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Sharif Moradi ◽  
Hamid Mahdizadeh ◽  
Tomo Šarić ◽  
Johnny Kim ◽  
Javad Harati ◽  
...  
Keyword(s):  
Stem Cells ◽  
Induced Pluripotent Stem Cells ◽  
Cell Fate ◽  
Pluripotent Stem Cells ◽  
Cell Types ◽  
Healthy Person ◽  
New Drugs ◽  
Full Potential ◽  
Cell Fate Decisions ◽  
Induced Pluripotent

AbstractInduced pluripotent stem cells (iPSCs) can self-renew indefinitely in culture and differentiate into all specialized cell types including gametes. iPSCs do not exist naturally and are instead generated (“induced” or “reprogrammed”) in culture from somatic cells through ectopic co-expression of defined pluripotency factors. Since they can be generated from any healthy person or patient, iPSCs are considered as a valuable resource for regenerative medicine to replace diseased or damaged tissues. In addition, reprogramming technology has provided a powerful tool to study mechanisms of cell fate decisions and to model human diseases, thereby substantially potentiating the possibility to (i) discover new drugs in screening formats and (ii) treat life-threatening diseases through cell therapy-based strategies. However, various legal and ethical barriers arise when aiming to exploit the full potential of iPSCs to minimize abuse or unauthorized utilization. In this review, we discuss bioethical, legal, and societal concerns associated with research and therapy using iPSCs. Furthermore, we present key questions and suggestions for stem cell scientists, legal authorities, and social activists investigating and working in this field.

scholarly journals Noncanonical NOTCH Signaling Limits Self-Renewal of Human Epithelial and Induced Pluripotent Stem Cells through ROCK Activation

2013 ◽  
Vol 33 (22) ◽  
pp. 4434-4447 ◽  
Author(s):  
Takashi Yugawa ◽  
Koichiro Nishino ◽  
Shin-ichi Ohno ◽  
Tomomi Nakahara ◽  
Masatoshi Fujita ◽  
...  
Keyword(s):  
Stem Cells ◽  
Induced Pluripotent Stem Cells ◽  
Cell Fate ◽  
Pluripotent Stem Cells ◽  
Human Keratinocytes ◽  
Small Gtpase ◽  
Keratinocyte Differentiation ◽  
Growth Defect ◽  
Self Renewal ◽  
Induced Pluripotent

NOTCH plays essential roles in cell fate specification during embryonic development and in adult tissue maintenance. In keratinocytes, it is a key inducer of differentiation. ROCK, an effector of the small GTPase Rho, is also implicated in keratinocyte differentiation, and its inhibition efficiently potentiates immortalization of human keratinocytes and greatly improves survival of dissociated human pluripotent stem cells. However, the molecular basis for ROCK activation is not fully established in these contexts. Here we provide evidence that intracellular forms of NOTCH1 trigger the immediate activation of ROCK1 independent of its transcriptional activity, promoting differentiation and resulting in decreased clonogenicity of normal human keratinocytes. Knockdown of NOTCH1 abrogated ROCK1 activation and conferred sustained clonogenicity upon differentiation stimuli. Treatment with a ROCK inhibitor, Y-27632, or ROCK1 silencing substantially rescued the growth defect induced by activated NOTCH1. Furthermore, we revealed that impaired self-renewal of human induced pluripotent stem cells upon dissociation is, at least in part, attributable to NOTCH-dependent ROCK activation. Thus, the present study unveils a novel NOTCH-ROCK pathway critical for cellular differentiation and loss of self-renewal capacity in a subset of immature cells.

scholarly journals Definitive Endoderm Formation from Plucked Human Hair-Derived Induced Pluripotent Stem Cells and SK Channel Regulation

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Anett Illing ◽  
Marianne Stockmann ◽  
Narasimha Swamy Telugu ◽  
Leonhard Linta ◽  
Ronan Russell ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Induced Pluripotent Stem Cells ◽  
Cell Fate ◽  
Pluripotent Stem Cells ◽  
Human Hair ◽  
Definitive Endoderm ◽  
Sk Channel ◽  
Induced Pluripotent

Pluripotent stem cells present an extraordinary powerful tool to investigate embryonic development in humans. Essentially, they provide a unique platform for dissecting the distinct mechanisms underlying pluripotency and subsequent lineage commitment. Modest information currently exists about the expression and the role of ion channels during human embryogenesis, organ development, and cell fate determination. Of note, small and intermediate conductance, calcium-activated potassium channels have been reported to modify stem cell behaviour and differentiation. These channels are broadly expressed throughout human tissues and are involved in various cellular processes, such as the after-hyperpolarization in excitable cells, and also in differentiation processes. To this end, human induced pluripotent stem cells (hiPSCs) generated from plucked human hair keratinocytes have been exploitedin vitroto recapitulate endoderm formation and, concomitantly, used to map the expression of the SK channel (SKCa) subtypes over time. Thus, we report the successful generation of definitive endoderm from hiPSCs of ectodermal origin using a highly reproducible and robust differentiation system. Furthermore, we provide the first evidence that SKCas subtypes are dynamically regulated in the transition from a pluripotent stem cell to a more lineage restricted, endodermal progeny.

scholarly journals Widespread conservation of chromatin accessibility patterns and transcription factor binding in human and chimpanzee induced pluripotent stem cells

2018 ◽  
Author(s):  
Irene Gallego Romero ◽  
Shyam Gopalakrishnan ◽  
Yoav Gilad
Keyword(s):  
Stem Cells ◽  
Transcription Factor ◽  
Induced Pluripotent Stem Cells ◽  
Pluripotent Stem Cells ◽  
Related Species ◽  
Transcription Factor Binding ◽  
Chromatin Accessibility ◽  
Closely Related Species ◽  
Factor Binding ◽  
Induced Pluripotent

AbstractChanges in gene regulation have been shown to contribute to phenotypic differences between closely related species, most notably in primates. It is likely that a subset of inter-species regulatory differences can be explained by changes in chromatin accessibility and transcription factor binding, yet there is a paucity of comparative data sets with which to investigate this. Using ATAC-seq, we profiled genome-wide chromatin accessibility in a matched set of 6 human and 6 chimpanzee (Pan troglodytes, our closest living relative) induced pluripotent stem cells from which we have previously collected gene expression data. We examined chromatin accessibility patterns near 20,745 orthologous transcriptions start sites and used a footprinting algorithm to predict transcription factor binding activity in each species. We found that the majority of chromatin accessibility patterns and transcription factor activity are conserved between these two closely related species. Interestingly, interspecies divergence in chromatin accessibility and transcription factor binding in pluripotent cells appear to contribute not to differences in the pluripotent state, but to downstream developmental processes. Put together, our findings suggest that the pluripotent state is extremely stable and potentially subject to stronger evolutionary constraint than other somatic tissues.

scholarly journals Derivation of trophoblast stem cells from naïve human pluripotent stem cells

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Chen Dong ◽  
Mariana Beltcheva ◽  
Paul Gontarz ◽  
Bo Zhang ◽  
Pooja Popli ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cell Fate ◽  
Pluripotent Stem Cells ◽  
Chromatin Accessibility ◽  
Human Pluripotent Stem Cells ◽  
Human Trophoblast ◽  
Trophoblast Stem Cells ◽  
Cell Fate Decisions ◽  
Trophoblast Stem ◽  
Normal Human

Naïve human pluripotent stem cells (hPSCs) provide a unique experimental platform of cell fate decisions during pre-implantation development, but their lineage potential remains incompletely characterized. As naïve hPSCs share transcriptional and epigenomic signatures with trophoblast cells, it has been proposed that the naïve state may have enhanced predisposition for differentiation along this extraembryonic lineage. Here we examined the trophoblast potential of isogenic naïve and primed hPSCs. We found that naïve hPSCs can directly give rise to human trophoblast stem cells (hTSCs) and undergo further differentiation into both extravillous and syncytiotrophoblast. In contrast, primed hPSCs do not support hTSC derivation, but give rise to non-self-renewing cytotrophoblasts in response to BMP4. Global transcriptome and chromatin accessibility analyses indicate that hTSCs derived from naïve hPSCs are similar to blastocyst-derived hTSCs and acquire features of post-implantation trophectoderm. The derivation of hTSCs from naïve hPSCs will enable elucidation of early mechanisms that govern normal human trophoblast development and associated pathologies.

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