scholarly journals When the Search for Stemness Genes Meets the Skin Substitute Bioengineering Field: KLF4 Transcription Factor under the Light

Cells ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 2188
Author(s):  
Nicolas O. Fortunel ◽  
Michèle T. Martin
Keyword(s):  
Stem Cells ◽  
Transcription Factor ◽  
Cell Biology ◽  
Ex Vivo ◽  
Embryonic Stem ◽  
Human Keratinocytes ◽  
Keratinocyte Differentiation ◽  
Skin Substitute ◽  
Large Set ◽  
Tgf Β1

The transcription factor “Kruppel-like factor 4” (KLF4) is a central player in the field of pluripotent stem cell biology. In particular, it was put under the spotlight as one of the four factors of the cocktail originally described for reprogramming into induced pluripotent stem cells (iPSCs). In contrast, its possible functions in native tissue stem cells remain largely unexplored. We recently published that KLF4 is a regulator of “stemness” in human keratinocytes. We show that reducing the level of expression of this transcription factor by RNA interference or pharmacological repression promotes the ex vivo amplification and regenerative capacity of two types of cells of interest for cutaneous cell therapy: native keratinocyte stem and progenitor cells from adult epidermis, which have been used for more than three decades in skin graft bioengineering, and keratinocytes generated by the lineage-oriented differentiation of embryonic stem cells (ESCs), which have potential for the development of skin bio-bandages. At the mechanistic level, KLF4 repression alters the expression of a large set of genes involved in TGF-β1 and WNT signaling pathways. Major regulators of TGF-β bioavailability and different TGF-β receptors were targeted, notably modulating the ALK1/Smad1/5/9 axis. At a functional level, KLF4 repression produced an antagonist effect on TGF-β1-induced keratinocyte differentiation.

315 MELATONIN EFFECTS ON THE PROLIFERATION AND DIFFERENTIATION OF MOUSE EMBRYONIC STEM CELLS

2011 ◽  
Vol 23 (1) ◽  
pp. 254
Author(s):  
Y.-M. Yoo ◽  
E.-B. Jeung
Keyword(s):  
Stem Cells ◽  
Transcription Factor ◽  
Zinc Finger ◽  
Cellular Proliferation ◽  
Ex Vivo ◽  
Es Cells ◽  
Embryonic Stem ◽  
Melatonin Treatment ◽  
Proliferation And Differentiation

Mouse embryonic stem (ES) cells constitute a versatile biological system that can facilitate major advances in the fields of cell and developmental biology. Several studies have been performed to determine whether melatonin can affect ex vivo and in vitro proliferation and differentiation of stem cells (mesenchymal and neural stem cells derived human, rats, and mice), but its effect on ES cells is largely unknown. Thus, we further examined in this study the effects of melatonin at biological or pharmacological concentrations (100 or 200 μM) on the proliferation and differentiation of ES cells (ES-E14TG2a cells) using an in vitro culture system (n = 3) by Western blot analysis and real-time PCR. We found that melatonin at 100 and 200 μM resulted in cellular proliferation and phosphorylation of ERK and Akt, respectively. Melatonin treatment also increased Bcl-2 expression and suppressed Bax gene expression and increased phosphorylation of GSK α/β. The transcription factor Oct-4, which contains the POU (N-terminal to homeobox) domain, and the transcription factor Sox2, the zinc finger transcription factor Zfp206, and the zinc finger gene REX-1 (Znf42), which contain the high mobility group domain, are all important for cellular pluripotency and preimplantation development. In this study, melatonin (100 μM) treatment induced Oct-4 and REX-1 expression at day 1 but not at days 2 and 3. In addition, Sox2 and Zfp206 expressions were not altered following melatonin treatment. Taken together, these results suggest that melatonin may affect Akt phosphorylation and stem cell proliferation at biological or pharmacological concentrations.

scholarly journals Formative pluripotent stem cells show features of epiblast cells poised for gastrulation

Cell Research ◽  
2021 ◽  
Author(s):  
Xiaoxiao Wang ◽  
Yunlong Xiang ◽  
Yang Yu ◽  
Ran Wang ◽  
Yu Zhang ◽  
...  
Keyword(s):  
Stem Cells ◽  
Germ Cells ◽  
Pluripotent Stem Cells ◽  
Primordial Germ Cells ◽  
Embryonic Stem ◽  
Large Set ◽  
Mouse Escs ◽  
Epiblast Stem Cells ◽  
Early Gastrula

AbstractThe pluripotency of mammalian early and late epiblast could be recapitulated by naïve embryonic stem cells (ESCs) and primed epiblast stem cells (EpiSCs), respectively. However, these two states of pluripotency may not be sufficient to reflect the full complexity and developmental potency of the epiblast during mammalian early development. Here we report the establishment of self-renewing formative pluripotent stem cells (fPSCs) which manifest features of epiblast cells poised for gastrulation. fPSCs can be established from different mouse ESCs, pre-/early-gastrula epiblasts and induced PSCs. Similar to pre-/early-gastrula epiblasts, fPSCs show the transcriptomic features of formative pluripotency, which are distinct from naïve ESCs and primed EpiSCs. fPSCs show the unique epigenetic states of E6.5 epiblast, including the super-bivalency of a large set of developmental genes. Just like epiblast cells immediately before gastrulation, fPSCs can efficiently differentiate into three germ layers and primordial germ cells (PGCs) in vitro. Thus, fPSCs highlight the feasibility of using PSCs to explore the development of mammalian epiblast.

Positive regulators of the lineage-specific transcription factor GATA-1 in differentiating erythroid cells

1994 ◽  
Vol 14 (5) ◽  
pp. 3108-3114
Author(s):  
M H Baron ◽  
S M Farrington
Keyword(s):  
Gene Expression ◽  
Stem Cells ◽  
Transcription Factor ◽  
Embryonic Stem Cells ◽  
Cultured Cells ◽  
Globin Gene ◽  
Embryonic Stem ◽  
Targeted Mutagenesis ◽  
Erythroid Cell ◽  
Erythroid Cells

The zinc finger transcription factor GATA-1 is a major regulator of gene expression in erythroid, megakaryocyte, and mast cell lineages. GATA-1 binds to WGATAR consensus motifs in the regulatory regions of virtually all erythroid cell-specific genes. Analyses with cultured cells and cell-free systems have provided strong evidence that GATA-1 is involved in control of globin gene expression during erythroid differentiation. Targeted mutagenesis of the GATA-1 gene in embryonic stem cells has demonstrated its requirement in normal erythroid development. Efficient rescue of the defect requires an intact GATA element in the distal promoter, suggesting autoregulatory control of GATA-1 transcription. To examine whether GATA-1 expression involves additional regulatory factors or is maintained entirely by an autoregulatory loop, we have used a transient heterokaryon system to test the ability of erythroid factors to activate the GATA-1 gene in nonerythroid nuclei. We show here that proerythroblasts and mature erythroid cells contain a diffusible activity (TAG) capable of transcriptional activation of GATA-1 and that this activity decreases during the terminal differentiation of erythroid cells. Nuclei from GATA-1- mutant embryonic stem cells can still be reprogrammed to express their globin genes in erythroid heterokaryons, indicating that de novo induction of GATA-1 is not required for globin gene activation following cell fusion.

scholarly journals Lineage specification of early embryos and embryonic stem cells at the dawn of enabling technologies

2017 ◽  
Vol 4 (4) ◽  
pp. 533-542 ◽  
Author(s):  
Guangdun Peng ◽  
Patrick P. L. Tam ◽  
Naihe Jing
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Biology ◽  
Developmental Process ◽  
Embryonic Stem ◽  
Molecular Signaling ◽  
Lineage Specification ◽  
Genomic Technologies ◽  
Enabling Technologies ◽  
Stem Cell Pluripotency

Abstract Establishment of progenitor cell populations and lineage diversity during embryogenesis and the differentiation of pluripotent stem cells is a fascinating and intricate biological process. Conceptually, an understanding of this developmental process provides a framework to integrate stem-cell pluripotency, cell competence and differentiating potential with the activity of extrinsic and intrinsic molecular determinants. The recent advent of enabling technologies of high-resolution transcriptome analysis at the cellular, population and spatial levels proffers the capability of gaining deeper insights into the attributes of the gene regulatory network and molecular signaling in lineage specification and differentiation. In this review, we provide a snapshot of the emerging enabling genomic technologies that contribute to the study of development and stem-cell biology.

scholarly journals First person – Federico Pecori

2020 ◽  
Vol 133 (20) ◽  
pp. jcs255166
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Embryonic Stem Cells ◽  
Cell Biology ◽  
Embryonic Stem ◽  
Early Career ◽  
First Person ◽  
Receptor Endocytosis ◽  
Early Career Researchers ◽  
Selection Of

ABSTRACTFirst Person is a series of interviews with the first authors of a selection of papers published in Journal of Cell Science, helping early-career researchers promote themselves alongside their papers. Federico Pecori is first author on ‘Mucin-type O-glycosylation controls pluripotency in mouse embryonic stem cells via Wnt receptor endocytosis’, published in JCS. Federico is a PhD student in the lab of Shoko Nishihara at the Laboratory of Cell Biology, Department of Bioinformatics, Soka University, Tokyo, Japan, where he is interested in the mechanisms regulating stem cell identity.

scholarly journals MOV10 facilitates messenger RNA decay in an N6-methyladenosine (m6A) dependent manner to maintain the mouse embryonic stem cells state

2021 ◽  
Author(s):  
Majid Mehravar ◽  
Yogesh Kumar ◽  
Moshe Olshansky ◽  
Dhiru Bansal ◽  
Craig Dent ◽  
...  
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Cell Biology ◽  
Messenger Rna ◽  
Mrna Decay ◽  
Embryonic Stem ◽  
Mouse Embryonic Stem Cells ◽  
Beta Catenin ◽  
Dependent Manner ◽  
Leukaemia Virus

N6-methyladenosine (m6A) is the most predominant internal mRNA modification in eukaryotes, recognised by its reader proteins (so-called m6A-readers) for regulating subsequent mRNA fates, such as splicing, export, localisation, decay, stability, and translation to control several biological processes. Although a few m6A-readers have been identified, yet the list is incomplete. Here, we identify a new m6A-reader protein, Moloney leukaemia virus 10 homologue (MOV10), in mouse embryonic stem cells (mESCs). MOV10 recognises m6A-containing mRNAs with a conserved GGm6ACU motif. Mechanistic studies uncover that MOV10 facilitates mRNA decay of its bound m6A- containing mRNAs in an m6A-dependent manner within the cytoplasmic processing bodies (P-bodies). Furthermore, MOV10 decays the Gsk-3beta mRNA through m6A that stabilises the BETA-CATENIN expression of a WNT/BETA-CATENIN signalling pathway to regulate downstream NANOG expression for maintaining the mESC state. Thus, our findings reveal how a newly identified m6A-reader, MOV10 mediates mRNA decay via m6A that impact embryonic stem cell biology.

Establishment of human OCT4 as a putative HSP90 client protein : a case for HSP90 chaperoning pluripotency

2015 ◽  
Author(s):  
◽  
Jason Neville Sterrenberg
Keyword(s):  
Stem Cells ◽  
Transcription Factor ◽  
Stem Cell ◽  
Cell Biology ◽  
Therapeutic Potential ◽  
Stem Cell Biology ◽  
Client Protein ◽  
Hsp90 Inhibition ◽  
Regulated Gene Expression ◽  
Hsp90 Client Protein

The therapeutic potential of stem cells is already being harnessed in clinical trails. Of even greater therapeutic potential has been the discovery of mechanisms to reprogram differentiated cells into a pluripotent stem cell-like state known as induced pluripotent stem cells (iPSCs). Stem cell nature is governed and maintained by a hierarchy of transcription factors, the apex of which is OCT4. Although much research has elucidated the transcriptional regulation of OCT4, OCT4 regulated gene expression profiles and OCT4 transcriptional activation mechanisms in both stem cell biology and cellular reprogramming to iPSCs, the fundamental biochemistry surrounding the OCT4 transcription factor remains largely unknown. In order to analyze the biochemical relationship between HSP90 and human OCT4 we developed an exogenous active human OCT4 expression model with human OCT4 under transcriptional control of a constitutive promoter. We identified the direct interaction between HSP90 and human OCT4 despite the fact that the proteins predominantly display differential subcellular localizations. We show that HSP90 inhibition resulted in degradation of human OCT4 via the ubiquitin proteasome degradation pathway. As human OCT4 and HSP90 did not interact in the nucleus, we suggest that HSP90 functions in the cytoplasmic stabilization of human OCT4. Our analysis suggests HSP90 inhibition inhibits the transcriptional activity of human OCT4 dimers without affecting monomeric OCT4 activity. Additionally our data suggests that the HSP90 and human OCT4 complex is modulated by phosphorylation events either promoting or abrogating the interaction between HSP90 and human OCT4. Our data suggest that human OCT4 displays the characteristics describing HSP90 client proteins, therefore we identify human OCT4 as a putative HSP90 client protein. The regulation of the transcription factor OCT4 by HSP90 provides fundamental insights into the complex biochemistry of stem cell biology. This may also be suggestive that HSP90 not only regulates stem cell biology by maintaining routine cellular homeostasis but additionally through the direct regulation of pluripotency factors.

Abstract 17986: Molecular Beacon-based Purification of Ventricular Cardiomyocytes From Differentiating Embryonic Stem Cells by Targeting Intracellular Mrna

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Kiwon Ban ◽  
Brian Wile ◽  
Kyu-Won Cho ◽  
Sangsung Kim ◽  
Jason Singerd ◽  
...  
Keyword(s):  
Stem Cells ◽  
Transcription Factor ◽  
Embryonic Stem Cells ◽  
Cell Sorting ◽  
Disease Modeling ◽  
Embryonic Stem ◽  
Target Cells ◽  
Fluorescence Signal ◽  
Ventricular Cardiomyocytes ◽  
Specificity And Sensitivity

Background: Ventricular cardiomyocytes (CMs) are an ideal cell type for cardiac cell therapy since they are the main cells generating cardiac forces. However, isolating them from differentiating pluripotent stem cells (PSCs) has been challenging due to the lack of specific surface markers. Here we show that ventricular CMs can be purified from differentiating mouse embryonic stem cells (mESCs) using molecular beacons (MBs) targeting specific intracellular mRNAs. MBs are dual-labeled oligonucleotide hairpin probes that emit a fluorescence signal when hybridized to target mRNAs, allowing isolation of specific target cells by fluorescence activated cell sorting (FACS) with high specificity and sensitivity. Methods and Results: We generated three different MBs (IRX4-1, -2, -3) designed to target specific regions of mRNAs of iroquois homeobox protein 4 (Irx4), a specific transcription factor for ventricular CMs. Among three IRX4 MBs, IRX4-2 MB demonstrated the highest sensitivity and specificity, thus IRX4-2 MB was selected to purify mESC-derived ventricular CMs. Subsequently, IRX4-2 MBs were delivered into cardiomyogenically differentiating mESC cultures and cells showing strong signals from IRX4-2 MBs were FACS-sorted. Flow cytometry demonstrated that 92~97% of IRX4-2 MB-positive cells expressed a marker for ventricular CMs myosin light chain 2 ventricular isoform (Myl2) as well as cardiac troponin 2 (Tnnt2). Importantly, higher than 98% of IRX4-2 MB-positive cells displayed ventricular CM-like action potentials during electrophysiological analyses. These IRX4-2 MB-based purified ventricular CMs continuously maintained their CM characteristics verified by synchronous beating, Ca2+ transient, and expression of ventricular CM-specific proteins. Conclusions: We established a novel MB-based cell sorting system targeting a transcription factor that is specific for ventricular CM to generate homogeneous and functional ventricular CMs. This is the first report to show the feasibility of isolating pure ventricular CMs without modifying host genes, and this platform will be useful for therapeutic applications, disease modeling, and drug discovery.

The hSkn-1a POU transcription factor enhances epidermal stratification by promoting keratinocyte proliferation

2001 ◽  
Vol 114 (10) ◽  
pp. 1913-1923 ◽  
Author(s):  
J. Hildesheim ◽  
U. Kuhn ◽  
C.L. Yee ◽  
R.A. Foster ◽  
K.B. Yancey ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Human Keratinocytes ◽  
Dominant Negative ◽  
Keratinocyte Differentiation ◽  
Transactivation Domain ◽  
Hacat Keratinocytes ◽  
Primary Human Keratinocytes ◽  
Keratinocyte Proliferation ◽  
Proliferation And Differentiation ◽  
Epidermal Homeostasis

Skn-1a is a POU transcription factor that is primarily expressed in the epidermis and is known to modulate the expression of several genes associated with keratinocyte differentiation. However, the formation of a stratified epidermis requires a carefully controlled balance between keratinocyte proliferation and differentiation, and a role for Skn-1a in this process has not been previously demonstrated. Here, our results show, surprisingly, that human Skn-1a contributes to epidermal stratification by primarily promoting keratinocyte proliferation and secondarily by enhancing the subsequent keratinocyte differentiation. In organotypic raft cultures of both primary human keratinocytes and immortalized HaCaT keratinocytes, human Skn-1a expression is associated with increased keratinocyte proliferation and re-epithelialization of the dermal substrates, resulting in increased numbers of keratinocytes available for the differentiation process. In these same raft cultures, human Skn-1a expression enhances the phenotypic changes of keratinocyte differentiation and the upregulated expression of keratinocyte differentiation genes. Conversely, expression of a dominant negative human Skn-1a transcription factor lacking the C-terminal transactivation domain blocks keratinocytes from proliferating and stratifying. Keratinocyte stratification is dependent on a precise balance between keratinocyte proliferation and differentiation, and our results suggest that human Skn-1a has an important role in maintaining epidermal homeostasis by promoting keratinocyte proliferation.

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