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 ◽  
...  
2020 ◽  
Author(s):  
Barbara Mojsa ◽  
Michael H. Tatham ◽  
Lindsay Davidson ◽  
Magda Liczmanska ◽  
Jane E. Wright ◽  
...  

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.


2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Sharif Moradi ◽  
Hamid Mahdizadeh ◽  
Tomo Šarić ◽  
Johnny Kim ◽  
Javad Harati ◽  
...  

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.


PLoS ONE ◽  
2012 ◽  
Vol 7 (1) ◽  
pp. e30234 ◽  
Author(s):  
Luca Orlando ◽  
Yolanda Sanchez-Ripoll ◽  
James Foster ◽  
Heather Bone ◽  
Claudia Giachino ◽  
...  

2013 ◽  
Vol 33 (22) ◽  
pp. 4434-4447 ◽  
Author(s):  
Takashi Yugawa ◽  
Koichiro Nishino ◽  
Shin-ichi Ohno ◽  
Tomomi Nakahara ◽  
Masatoshi Fujita ◽  
...  

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.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Rui Liu ◽  
Dong Li ◽  
Fangxu Sun ◽  
Antonio Rampoldi ◽  
Joshua T. Maxwell ◽  
...  

Abstract Background Treatment-induced cardiotoxicity is a leading noncancer-related cause of acute and late onset morbidity and mortality in cancer patients on antineoplastic drugs such as melphalan—increasing clinical case reports have documented that it could induce cardiotoxicity including severe arrhythmias and heart failure. As the mechanism by which melphalan impairs cardiac cells remains poorly understood, here, we aimed to use cardiomyocytes derived from human induced pluripotent stem cells (hiPSC-CMs) to investigate the cellular and molecular mechanisms of melphalan-induced cardiotoxicity. Methods hiPSC-CMs were generated and treated with clinically relevant doses of melphalan. To characterize melphalan-induced cardiotoxicity, cell viability and apoptosis were quantified at various treatment durations. Ca2+ transient and contractility analyses were used to examine the alterations of hiPSC-CM function. Proteomic analysis, reactive oxygen species detection, and RNA-Sequencing were conducted to investigate underlying mechanisms. Results Melphalan treatment of hiPSC-CMs induced oxidative stress, caused Ca2+ handling defects and dysfunctional contractility, altered global transcriptomic and proteomic profiles, and resulted in apoptosis and cell death. The antioxidant N-acetyl-l-cysteine attenuated these genomic, cellular, and functional alterations. In addition, several other signaling pathways including the p53 and transforming growth factor-β signaling pathways were also implicated in melphalan-induced cardiotoxicity according to the proteomic and transcriptomic analyses. Conclusions Melphalan induces cardiotoxicity through the oxidative stress pathway. This study provides a unique resource of the global transcriptomic and proteomic datasets for melphalan-induced cardiotoxicity and can potentially open up new clinical mechanism-based targets to prevent and treat melphalan-induced cardiotoxicity.


2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Anett Illing ◽  
Marianne Stockmann ◽  
Narasimha Swamy Telugu ◽  
Leonhard Linta ◽  
Ronan Russell ◽  
...  

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.


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