scholarly journals Competence to epithelialise coincides with competence to differentiate in pluripotent cells

2019 ◽  
Author(s):  
Chia-Yi Lin ◽  
Tulin Tatar ◽  
Guillaume Blin ◽  
Mattias Malaguti ◽  
Rosa Portero Migueles ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Quantitative Imaging ◽  
Laminin Receptor ◽  
Pluripotent Cells ◽  
Integrin Alpha3

SummaryPluripotent cells reorganise themselves into an epithelium before they initiate differentiation, but it is not clear how these two events are mechanistically linked. Here we use quantitative imaging approaches to measure cellular rearrangements that accompany exit from naive pluripotency. We show that competence to epithelialise, like competence to differentiate, is a regulated process. The pro-differentiation transcription factor Tcf15 prospectively identifies cells that are competent to epithelialise. We identify early upregulation of the laminin receptor integrin alpha3 prior to differentiation and show that Tcf15 helps to regulate this change. Finally, we show that Tcf15 identifies and is required for efficient differentiation of a primed subpopulation of pluripotent cells. We conclude that competence to epithelialise is actively regulated and linked to differentiation-competence through the transcription factor Tcf15.

scholarly journals The BTB transcription factors ZBTB11 and ZFP131 maintain pluripotency by pausing POL II at pro-differentiation genes

2020 ◽  
Author(s):  
Görkem Garipler ◽  
Congyi Lu ◽  
Alexis Morrissey ◽  
Lorena S. Lopez-Zepeda ◽  
Simon E. Vidal ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Stem Cell ◽  
Transcription Factors ◽  
Embryonic Stem ◽  
Loss Of Function ◽  
Pluripotent Cells ◽  
Pol Ii ◽  
Crispr Screen ◽  
Rapid Activation ◽  
Factor Release

AbstractIn pluripotent cells, a delicate activation-repression balance maintains pro-differentiation genes ready for rapid activation. The identity of transcription factors (TFs) that specifically repress pro-differentiation genes remains obscure. By targeting ~1,700 TFs with CRISPR loss-of-function screen, we found that ZBTB11 and ZFP131 are required for embryonic stem cell (ESC) pluripotency. ZBTB11 and ZFP131 maintain promoter-proximally paused Polymerase II at pro-differentiation genes in ESCs. ZBTB11 or ZFP131 loss leads to NELF pausing factor release, an increase in H3K4me3, and transcriptional upregulation of genes associated with all three germ layers. Together, our results suggest that ZBTB11 and ZFP131 maintain pluripotency by preventing premature expression of pro-differentiation genes and present a generalizable framework to maintain cellular potency.One-sentence summaryA Transcription Factor-wide CRISPR screen identifies ZBTB11 and ZFP131 maintaining pluripotency by pausing POL II at pro-differentiation genes

scholarly journals miR-203 imposes an intrinsic barrier during cellular reprogramming by targeting NFATC2

2020 ◽  
Author(s):  
María Salazar-Roa ◽  
Sara Martínez-Martínez ◽  
Osvaldo Graña-Castro ◽  
Mónica Álvarez-Fernández ◽  
Marianna Trakala ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Cellular Reprogramming ◽  
Pluripotent Cells ◽  
Multiple Functions ◽  
Genetic Ablation ◽  
Cellular Models ◽  
Reprogramming Factors ◽  
Early Phases

AbstractCellular reprogramming from somatic to pluripotent cells is the basis for multiple applications aimed to replace damaged tissues in regenerative medicine. However, this process is limited by intrinsic barriers that are induced in response to reprogramming factors. In this manuscript we report that miR-203, a microRNA with multiple functions in differentiation and tumor suppression, acts as an endogenous barrier to reprogramming. Genetic ablation of miR-203 results in enhanced reprogramming whereas its expression prevents the formation of pluripotent cells both in vitro and in vivo. Mechanistically, this effect correlates with the direct repression of NFATC2, a transcription factor involved in the early phases of reprogramming. Inhibition of NFATC2 mimics miR-203 effects whereas NFATC2 overexpression rescues inducible cell pluripotency in miR-203-overexpressing cultures. These data suggest that miR-203 repression may favor the efficiency of reprogramming in a variety of cellular models.

scholarly journals CTCF is a barrier for 2C-like reprogramming

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Teresa Olbrich ◽  
Maria Vega-Sendino ◽  
Desiree Tillo ◽  
Wei Wu ◽  
Nicholas Zolnerowich ◽  
...  
Keyword(s):  
Dna Damage ◽  
Transcription Factor ◽  
Transcriptional Activation ◽  
Binding Sites ◽  
Neural Progenitor Cells ◽  
Ctcf Binding ◽  
Pluripotent Cells ◽  
Embryonic Tissues ◽  
Binding Factor ◽  
Molecular Determinants

AbstractTotipotent cells have the ability to generate embryonic and extra-embryonic tissues. Interestingly, a rare population of cells with totipotent-like potential, known as 2 cell (2C)-like cells, has been identified within ESC cultures. They arise from ESC and display similar features to those found in the 2C embryo. However, the molecular determinants of 2C-like conversion have not been completely elucidated. Here, we show that the CCCTC-binding factor (CTCF) is a barrier for 2C-like reprogramming. Indeed, forced conversion to a 2C-like state by the transcription factor DUX is associated with DNA damage at a subset of CTCF binding sites. Depletion of CTCF in ESC efficiently promotes spontaneous and asynchronous conversion to a 2C-like state and is reversible upon restoration of CTCF levels. This phenotypic reprogramming is specific to pluripotent cells as neural progenitor cells do not show 2C-like conversion upon CTCF-depletion. Furthermore, we show that transcriptional activation of the ZSCAN4 cluster is necessary for successful 2C-like reprogramming. In summary, we reveal an unexpected relationship between CTCF and 2C-like reprogramming.

scholarly journals The transcription factor E2A drives neural differentiation in pluripotent cells

Development ◽  
2020 ◽  
Vol 147 (12) ◽  
pp. dev184093
Author(s):  
Chandrika Rao ◽  
Mattias Malaguti ◽  
John O. Mason ◽  
Sally Lowell
Keyword(s):  
Transcription Factor ◽  
Neural Differentiation ◽  
Pluripotent Cells

scholarly journals Mutation of sequences flanking and separating transcription factor binding sites in a Drosophila enhancer significantly alter its output

2018 ◽  
Author(s):  
Xiao-Yong Li ◽  
Michael B. Eisen
Keyword(s):  
Transcription Factor ◽  
Binding Sites ◽  
Quantitative Imaging ◽  
Transcription Factor Binding Sites ◽  
Transcription Factor Binding ◽  
Enhancer Activity ◽  
Factor Binding ◽  
Pioneer Factor ◽  
The Relationship ◽  
Modest Effect

AbstractHere we explore how mutating different sequences in an enhancer that regulates patterned gene expression in Drosophila melanogaster embryos can affect its output. We used quantitative imaging to analyze the effects of a wide variety of mutations in the hunchback distal anterior enhancer. This enhancer has been shown to respond to the anterior morphogen Bicoid, but we found that mutations in only one of the five strong Bicoid sites in the enhancer has a significant effect on its binding. The pioneer factor Zelda, which binds to this enhancer and is the only other factor implicated in its activity besides Bicoid. However, we found that mutations of all its sites only has modest effect that is limited to reduction of its output in more posterior regions of the embryo, where Bicoid levels are low. In contrast to the modest effects of mutating known transcription factor binding sites, randomizing the sequences between Zelda and Bicoid sites significantly compromised enhancer activity. Finer mapping suggested that the sequences that determine activity are broadly distributed in the enhancer. Mutations in short sequences flanking Bicoid binding sites have stronger effects than mutations to Bicoid sites themselves, highlighting the complex and counterintuitive nature of the relationship between enhancer sequence and activity.

scholarly journals The transcription factor E2A drives neural differentiation in pluripotent cells

2019 ◽  
Author(s):  
Chandrika Rao ◽  
Mattias Malaguti ◽  
John O. Mason ◽  
Sally Lowell
Keyword(s):  
Transcription Factor ◽  
Neural Differentiation ◽  
Bhlh Transcription Factor ◽  
Pluripotent Cells ◽  
Neural Lineage ◽  
Binding Partner ◽  
Helix Loop Helix ◽  
Id Proteins ◽  
Mouse Cells ◽  
Extracellular Signalling

AbstractThe intrinsic mechanisms that link extracellular signalling to the onset of neural differentiation are not well understood. In pluripotent mouse cells, BMP blocks entry into the neural lineage via transcriptional upregulation of Inhibitor of Differentiation (Id) factors. We have previously identified that the major binding partner of Id proteins in pluripotent cells is the basic helix-loop-helix (bHLH) transcription factor (TF), E2A. Id1 can prevent E2A from forming heterodimers with bHLH TFs or from forming homodimers. Here, we show that overexpression of a forced E2A homodimer is sufficient to drive robust neural commitment in pluripotent cells, even under non-permissive conditions. Conversely, we find that E2A null cells display a defect in their neural differentiation capacity. E2A acts as an upstream activator of neural lineage genes, including Sox1 and Foxd4, and as a repressor of Nodal signalling. Our results suggest a crucial role for E2A in establishing neural lineage commitment in pluripotent cells.

Transcription factor/DNA interactions visualized by electron spectroscopic imaging

1992 ◽  
Vol 50 (1) ◽  
pp. 450-451
Author(s):  
David P. Bazett-Jones ◽  
Mark L. Brown
Keyword(s):  
Transcription Factor ◽  
Dna Sequences ◽  
Transcription Initiation ◽  
Molecular Mechanisms ◽  
Phosphorus Content ◽  
Spectroscopic Imaging ◽  
Electron Spectroscopic Imaging ◽  
Dna Backbone ◽  
Two Parameters ◽  
High Level

A multisubunit RNA polymerase enzyme is ultimately responsible for transcription initiation and elongation of RNA, but recognition of the proper start site by the enzyme is regulated by general, temporal and gene-specific trans-factors interacting at promoter and enhancer DNA sequences. To understand the molecular mechanisms which precisely regulate the transcription initiation event, it is crucial to elucidate the structure of the transcription factor/DNA complexes involved. Electron spectroscopic imaging (ESI) provides the opportunity to visualize individual DNA molecules. Enhancement of DNA contrast with ESI is accomplished by imaging with electrons that have interacted with inner shell electrons of phosphorus in the DNA backbone. Phosphorus detection at this intermediately high level of resolution (≈lnm) permits selective imaging of the DNA, to determine whether the protein factors compact, bend or wrap the DNA. Simultaneously, mass analysis and phosphorus content can be measured quantitatively, using adjacent DNA or tobacco mosaic virus (TMV) as mass and phosphorus standards. These two parameters provide stoichiometric information relating the ratios of protein:DNA content.

Fluorescent potentiometric dyes for membrane-potential imaging

1994 ◽  
Vol 52 ◽  
pp. 166-167
Author(s):  
Leslie M. Loew
Keyword(s):  
Membrane Potential ◽  
Single Cells ◽  
Quantitative Imaging ◽  
Optical Recording ◽  
Biological Processes ◽  
Major Focus ◽  
The Past ◽  
Excitable Systems ◽  
Major Application ◽  
The Impact

A major application of potentiometric dyes has been the multisite optical recording of electrical activity in excitable systems. After being championed by L.B. Cohen and his colleagues for the past 20 years, the impact of this technology is rapidly being felt and is spreading to an increasing number of neuroscience laboratories. A second class of experiments involves using dyes to image membrane potential distributions in single cells by digital imaging microscopy - a major focus of this lab. These studies usually do not require the temporal resolution of multisite optical recording, being primarily focussed on slow cell biological processes, and therefore can achieve much higher spatial resolution. We have developed 2 methods for quantitative imaging of membrane potential. One method uses dual wavelength imaging of membrane-staining dyes and the other uses quantitative 3D imaging of a fluorescent lipophilic cation; the dyes used in each case were synthesized for this purpose in this laboratory.

The role of transcription factor Egr‐1 in IL‐1 up‐regulation of tubular CD44 expression

Nephrology ◽  
2000 ◽  
Vol 5 (3) ◽  
pp. A92-A92
Author(s):  
Takazoe K ◽  
Foti R ◽  
Hurst La ◽  
Atkins Rc ◽  
Nikolic‐Paterson DJ.
Keyword(s):  
Transcription Factor ◽  
Cd44 Expression
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