Investigating cellular identity and manipulating cell fate using induced pluripotent stem cells

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.

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Corrigendum: Induced Pluripotent Stem Cells Derived From Two Idiopathic Azoospermia Patients Display Compromised Differentiation Potential for Primordial Germ Cell Fate

Frontiers in Cell and Developmental Biology ◽

10.3389/fcell.2020.00718 ◽

2020 ◽

Vol 8 ◽

Author(s):

Fang Fang ◽

Zili Li ◽

Qian Zhao ◽

Zhen Ye ◽

Xiuli Gu ◽

...

Keyword(s):

Stem Cells ◽

Germ Cell ◽

Induced Pluripotent Stem Cells ◽

Cell Fate ◽

Pluripotent Stem Cells ◽

Primordial Germ Cell ◽

Differentiation Potential ◽

Induced Pluripotent

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

Stem Cells International ◽

10.1155/2013/360573 ◽

2013 ◽

Vol 2013 ◽

pp. 1-13 ◽

Cited By ~ 12

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.

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Differentiation of Human Protein-Induced Pluripotent Stem Cells toward a Retinal Pigment Epithelial Cell Fate

PLoS ONE ◽

10.1371/journal.pone.0143272 ◽

2015 ◽

Vol 10 (11) ◽

pp. e0143272 ◽

Cited By ~ 11

Author(s):

Jie Gong ◽

Mark A. Fields ◽

Ernesto F. Moreira ◽

Hannah E. Bowrey ◽

Monika Gooz ◽

...

Keyword(s):

Stem Cells ◽

Epithelial Cell ◽

Induced Pluripotent Stem Cells ◽

Cell Fate ◽

Pluripotent Stem Cells ◽

Retinal Pigment Epithelial ◽

Retinal Pigment Epithelial Cell ◽

Retinal Pigment ◽

Pigment Epithelial ◽

Induced Pluripotent

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SUMO maintains the chromatin environment of human induced pluripotent stem cells

10.1101/2020.12.22.423944 ◽

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.

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

Stem Cells ◽

10.1002/stem.199 ◽

2009 ◽

Vol 27 (11) ◽

pp. 2655-2666 ◽

Cited By ~ 120

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

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Abstract 17442: Effects of Small Conductance Ca2+-activated K+ Channels on Cardiogenesis in Human Induced Pluripotent Stem Cells

Circulation ◽

10.1161/circ.132.suppl_3.17442 ◽

2015 ◽

Vol 132 (suppl_3) ◽

Author(s):

Imju Jeong ◽

Sergey Yechikov ◽

Jessica Gluck ◽

Deborah K Lieu

Keyword(s):

Stem Cells ◽

Induced Pluripotent Stem Cells ◽

Cell Fate ◽

Pluripotent Stem Cells ◽

Treatment Time ◽

Sk Channels ◽

Membrane Hyperpolarization ◽

K Channels ◽

Induced Pluripotent ◽

Small Conductance

Human induced pluripotent stem cells (hiPSCs) with the ability to form all somatic cells can generate pacemaking cardiomyocytes (CMs) for engineering of biological pacemakers. However, differentiation efficiency of hiPSCs into pacemaking cardiomyocytes is merely at 5% of the total CMs. Membrane potential of a cell can alter cell fate. Activation of small conductance Ca2+-activated K+ channels (SKs) has been shown to induce membrane hyperpolarization. In this study, we demonstrated that SKs are present and functional in hiPSCs and their differentiation progeny. Addition of SK activator (EBIO or CyPPA) hyperpolarized hiPSCs and differentiating hiPSCs 2 and 5 days post-differentiation by -2.5±0.97, -22.7±1.8 and -13.6±3.3 mV, respectively. The magnitude of hyperpolarization exhibited dose-dependency to SK activator in differentiating hiPSCs 2 days post-differentiation. Activation of SK channels by EBIO or CyPPA on day 2-3 from the onset of differentiation significantly upregulated the expression of Islet (Isl)1, a marker for a subset of cardiac progenitor cells that are known to form the sinoatrial node where the pacemaking cardiomyocyte reside. The number of Isl1-positive cells in differentiating hiPSCs with SK activation on day 2-3 has also increased relative to control. Our findings indicate that the activation of SK channels at an appropriate treatment time and length results in a facilitated increase in the differentiation of hiPSCs to pacemaking cardiomyocyte precursors.

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

Stem Cell Research & Therapy ◽

10.1186/s13287-019-1455-y ◽

2019 ◽

Vol 10 (1) ◽

Cited By ~ 12

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.

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