scholarly journals CFIm25 regulates human stem cell function independently of its role in mRNA alternative polyadenylation

2021 ◽  
Author(s):  
Chengguo Yao ◽  
Yi Ran ◽  
Shanshan Huang ◽  
Junjie Shi ◽  
Qiumin Feng ◽  
...  
Keyword(s):  
Rna Polymerase Ii ◽  
Gene Editing ◽  
Target Genes ◽  
Cellular Proliferation ◽  
Cell Function ◽  
Embryonic Stem ◽  
Alternative Polyadenylation ◽  
The Body ◽  
Processing Factor ◽  
Differentiation Potential

It has recently been shown that CFIm25, a canonical mRNA 3’ processing factor, could play a variety of physiological roles through its molecular function in the regulation of mRNA alternative polyadenylation (APA). Here, we used CRISPR/Cas9-mediated gene editing approach in human embryonic stem cells (hESCs) for CFIm25, and obtained three gene knockdown/mutant cell lines. CFIm25 gene editing resulted in higher proliferation rate and impaired differentiation potential for hESCs, with these effects likely to be directly regulated by the target genes, including the pluripotency factor rex1. Mechanistically, we unexpected found that perturbation in CFIm25 gene expression did not significantly affect cellular mRNA 3’ processing efficiency and APA profile. Rather, we provided evidences that CFIm25 may impact RNA polymerase II (RNAPII) occupancy at the body of transcribed genes, and promote the expression level of a group of transcripts associated with cellular proliferation and/or differentiation. Further study indicated that CFIm25 association with LEO1, an RNAPII associated factor, might contribute to the effect. Taken together, these results reveal novel mechanisms underlying CFIm25’s modulation in determination of cell fate, and provide evidence that the process of mammalian gene transcription may be regulated by an mRNA 3’ processing factor.

scholarly journals MLL1 is required for PAX7 expression and satellite cell self-renewal in mice

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Gregory C. Addicks ◽  
Caroline E. Brun ◽  
Marie-Claude Sincennes ◽  
John Saber ◽  
Christopher J. Porter ◽  
...  
Keyword(s):  
Satellite Cell ◽  
Satellite Cells ◽  
Transcriptional Activation ◽  
Cell Activation ◽  
Target Genes ◽  
Cell Function ◽  
Skeletal Muscle Regeneration ◽  
Differentiation Potential ◽  
Self Renewal

Abstract PAX7 is a paired-homeobox transcription factor that specifies the myogenic identity of muscle stem cells and acts as a nodal factor by stimulating proliferation while inhibiting differentiation. We previously found that PAX7 recruits the H3K4 methyltransferases MLL1/2 to epigenetically activate target genes. Here we report that in the absence of Mll1, myoblasts exhibit reduced H3K4me3 at both Pax7 and Myf5 promoters and reduced Pax7 and Myf5 expression. Mll1-deficient myoblasts fail to proliferate but retain their differentiation potential, while deletion of Mll2 had no discernable effect. Re-expression of PAX7 in committed Mll1 cKO myoblasts restored H3K4me3 enrichment at the Myf5 promoter and Myf5 expression. Deletion of Mll1 in satellite cells reduced satellite cell proliferation and self-renewal, and significantly impaired skeletal muscle regeneration. Pax7 expression was unaffected in quiescent satellite cells but was markedly downregulated following satellite cell activation. Therefore, MLL1 is required for PAX7 expression and satellite cell function in vivo. Furthermore, PAX7, but not MLL1, is required for Myf5 transcriptional activation in committed myoblasts.

The putative nuclear receptor mediator TIF1alpha is tightly associated with euchromatin

1999 ◽  
Vol 112 (11) ◽  
pp. 1671-1683 ◽  
Author(s):  
E. Remboutsika ◽  
Y. Lutz ◽  
A. Gansmuller ◽  
J.L. Vonesch ◽  
R. Losson ◽  
...  
Keyword(s):  
Rna Polymerase Ii ◽  
Nuclear Receptors ◽  
Target Genes ◽  
Es Cells ◽  
Embryonic Stem ◽  
Chromosomal Protein ◽  
Metaphase Chromosomes ◽  
Interphase Nuclei ◽  
Ec Cells ◽  
Early Mouse

Ligand-dependent transcriptional regulation by nuclear receptors is believed to be mediated by intermediary factors (TIFs) acting on remodelling of the chromatin structure and/or the activity of the transcriptional machinery. The putative transcriptional mediator TIF1alpha is a nuclear protein kinase that has been identified via its interaction with liganded nuclear receptors, including retinoic acid (RAR), retinoid X (RXR) and estrogen (ER) receptors. Here, we demonstrate that TIF1alpha is a non-histone chromosomal protein tightly associated with highly accessible euchromatic regions of the genome. Immunofluorescence confocal microscopy reveals that TIF1alpha exhibits a finely granular distribution in euchromatin of interphase nuclei, while it is mostly excluded from condensed chromatin and metaphase chromosomes. Immunoelectron microscopy shows that, in contrast to the heterochromatin protein HP1alpha, most of TIF1alpha is associated with euchromatin, where it is preferentially localised on regions known to be sites for RNA polymerase II (perichromatin fibrils and borders between euchromatin and heterochromatin). Early mouse embryos as well as embryonal carcinoma (EC) and embryonic stem (ES) cells express high levels of TIF1alpha. These levels dramatically decrease during organogenesis and upon differentiation of P19 EC cells, indicating that TIF1alpha is preferentially expressed in undifferentiated pluripotent cells in the course of development. Therefore, TIF1alpha could belong to a novel class of chromatin-associated TIFs that facilitate the access of transregulators (e.g. liganded nuclear receptors) to their cognate sites in target genes, thereby participitating in the epigenetic control of transcription during embryonic development and cell differentiation.

scholarly journals CREB Promotes Beta Cell Gene Expression by Targeting Its Coactivators to Tissue-Specific Enhancers

2019 ◽  
Vol 39 (17) ◽  
Author(s):  
Sam Van de Velde ◽  
Ezra Wiater ◽  
Melissa Tran ◽  
Yousang Hwang ◽  
Philip A. Cole ◽  
...  
Keyword(s):  
Gene Expression ◽  
Beta Cell ◽  
Rna Polymerase Ii ◽  
Target Genes ◽  
Cell Function ◽  
Pancreatic Beta Cell ◽  
Specific Gene ◽  
Distal Enhancer ◽  
Determining Factors ◽  
Cell Gene Expression

ABSTRACT CREB mediates effects of cyclic AMP on cellular gene expression. Ubiquitous CREB target genes are induced following recruitment of CREB and its coactivators to promoter proximal binding sites. We found that CREB stimulates the expression of pancreatic beta cell-specific genes by targeting CBP/p300 to promoter-distal enhancer regions. Subsequent increases in histone acetylation facilitate recruitment of the coactivators CRTC2 and BRD4, leading to release of RNA polymerase II over the target gene body. Indeed, CREB-induced hyperacetylation of chromatin over superenhancers promoted beta cell-restricted gene expression, which is sensitive to inhibitors of CBP/p300 and BRD4 activity. Neurod1 appears critical in establishing nucleosome-free regions for recruitment of CREB to beta cell-specific enhancers. Deletion of a CREB-Neurod1-bound enhancer within the Lrrc10b-Syt7 superenhancer disrupted the expression of both genes and decreased beta cell function. Our results demonstrate how cross talk between signal-dependent and lineage-determining factors promotes the expression of cell-type-specific gene programs in response to extracellular cues.

scholarly journals CDK12 is Necessary to Promote Epidermal Differentiation through Transcription Elongation

2021 ◽  
Author(s):  
George Sen ◽  
Jingting Li ◽  
Manisha Tiwari ◽  
Yifang Chen
Keyword(s):  
Transcription Factors ◽  
Rna Polymerase Ii ◽  
Cell Fate ◽  
Target Genes ◽  
Skin Diseases ◽  
Transcription Elongation ◽  
The Body ◽  
Epidermal Differentiation ◽  
Transcription Control ◽  
Cell Fate Decisions

Proper differentiation of the epidermis is essential to prevent water loss and to protect the body from the outside environment. Perturbations in this process can lead to a variety of skin diseases that impacts 1 in 5 people. While transcription factors that control epidermal differentiation have been well characterized, other aspects of transcription control such as elongation are poorly understood. Here we show that of the two cyclin dependent kinases (CDK12 and CDK13), that are known to regulate transcription elongation, only CDK12 is necessary for epidermal differentiation. Depletion of CDK12 led to loss of differentiation gene expression and absence of skin barrier formation in regenerated human epidermis. CDK12 binds to genes that code for differentiation promoting transcription factors (GRHL3, KLF4, and OVOL1) and is necessary for their elongation. CDK12 is necessary for elongation by promoting Ser2 phosphorylation on the C-terminal domain of RNA polymerase II and the binding of the elongation factor SPT6 to target genes. Our results suggest that control of transcription elongation by CDK12 plays a prominent role in adult cell fate decisions.

scholarly journals An RNA degradation complex required for silencing of Polycomb target genes

2019 ◽  
Author(s):  
Haining Zhou ◽  
Gergana Shipkovenska ◽  
Marian Kalocsay ◽  
Jiuchun Zhang ◽  
Zhenhua Luo ◽  
...  
Keyword(s):  
Ribosomal Rna ◽  
Rna Processing ◽  
Target Genes ◽  
Cellular Proliferation ◽  
Embryonic Stem ◽  
Rna Degradation ◽  
Chromatin Binding ◽  
Chromatin Compaction ◽  
Condensate Formation ◽  
Ribosomal Rna Processing

AbstractPolycomb Repressive Complex (PRC) 1 and 2 are histone-modifying and chromatin-binding complexes that are required for silencing of developmental regulatory genes and genes that control cellular proliferation. Their gene silencing functions are thought to involve chromatin compaction and condensate formation but whether other mechanisms contribute to silencing is unknown. Here we show that the rixosome, a conserved RNA degradation complex with roles in ribosomal RNA processing and heterochromatic RNA degradation in fission yeast, associates with human PRC complexes, is recruited to promoters of Polycomb target genes in differentiated cell lines and embryonic stem cells, and is required for efficient silencing of Polycomb target genes. These findings reveal an unanticipated role for RNA degradation in Polycomb-mediated silencing.

Transcriptional heterogeneity in mouse embryonic stem cells

2009 ◽  
Vol 21 (1) ◽  
pp. 67 ◽  
Author(s):  
Tetsuya S. Tanaka
Keyword(s):  
Cell Fate ◽  
Es Cells ◽  
Embryonic Stem ◽  
Cell Types ◽  
The Body ◽  
Cell Subpopulation ◽  
Es Cell ◽  
Differentiation Potential ◽  
Mouse Es Cells

The embryonic stem (ES) cell is a stem cell derived from early embryos that can indefinitely repeat self-renewing cell division cycles as an undifferentiated cell in vitro and give rise to all specialised cell types in the body. However, manipulating ES cell differentiation in vitro is a challenge due to, at least in part, heterogeneous gene induction. Recent experimental evidence has demonstrated that undifferentiated mouse ES cells maintained in culture exhibit heterogeneous expression of Dppa3, Nanog, Rex1, Pecam1 and Zscan4 as well as genes (Brachyury/T, Rhox6/9 and Twist2) normally expressed in specialised cell types. The Nanog-negative, Rex1-negative or T-positive ES cell subpopulation has a unique differentiation potential. Thus, studying the mechanism that generates ES cell subpopulations will improve manipulation of ES cell fate and help our understanding of the nature of embryonic development.

scholarly journals Acetylation of PAX7 controls muscle stem cell self-renewal and differentiation potential in mice

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Marie-Claude Sincennes ◽  
Caroline E. Brun ◽  
Alexander Y. T. Lin ◽  
Tabitha Rosembert ◽  
David Datzkiw ◽  
...  
Keyword(s):  
Stem Cell ◽  
Target Genes ◽  
Cell Function ◽  
Metabolic Adaptation ◽  
Acetyl Coa ◽  
Differentiation Potential ◽  
Muscle Stem Cell ◽  
Binding Motifs ◽  
Muscle Stem Cells ◽  
Stem Cell Divisions

AbstractMuscle stem cell function has been suggested to be regulated by Acetyl-CoA and NAD+ availability, but the mechanisms remain unclear. Here we report the identification of two acetylation sites on PAX7 that positively regulate its transcriptional activity. Lack of PAX7 acetylation reduces DNA binding, specifically to the homeobox motif. The acetyltransferase MYST1 stimulated by Acetyl-CoA, and the deacetylase SIRT2 stimulated by NAD +, are identified as direct regulators of PAX7 acetylation and asymmetric division in muscle stem cells. Abolishing PAX7 acetylation in mice using CRISPR/Cas9 mutagenesis leads to an expansion of the satellite stem cell pool, reduced numbers of asymmetric stem cell divisions, and increased numbers of oxidative IIA myofibers. Gene expression analysis confirms that lack of PAX7 acetylation preferentially affects the expression of target genes regulated by homeodomain binding motifs. Therefore, PAX7 acetylation status regulates muscle stem cell function and differentiation potential to facilitate metabolic adaptation of muscle tissue.

scholarly journals Evidence for Bone Marrow Adult Stem Cell Plasticity: Properties, Molecular Mechanisms, Negative Aspects, and Clinical Applications of Hematopoietic and Mesenchymal Stem Cells Transdifferentiation

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Ivana Catacchio ◽  
Simona Berardi ◽  
Antonia Reale ◽  
Annunziata De Luisi ◽  
Vito Racanelli ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Mesenchymal Stem Cells ◽  
Adult Stem Cells ◽  
Molecular Mechanisms ◽  
Embryonic Stem ◽  
Clinical Importance ◽  
The Body ◽  
Differentiation Potential ◽  
New Findings

In contrast to the pluripotentembryonic stem cells(ESCs) which are able to give rise to all cell types of the body, mammalianadult stem cells(ASCs) appeared to be more limited in their differentiation potential and to be committed to their tissue of origin. Recently, surprising new findings have contradicted central dogmas of commitment of ASCs by showing their plasticity to differentiate across tissue lineage boundaries, irrespective of classical germ layer designations. The present paper supports the plasticity of thebone marrow stem cells(BMSCs), bringing the most striking and the latest evidences of the transdifferentiation properties of thebone marrow hematopoietic and mesenchymal stem cells(BMHSCs, and BMMSCs), the two BM populations of ASCs better characterized. In addition, we report the possible mechanisms that may explain these events, outlining the clinical importance of these phenomena and the relative problems.

Mesenchymal Stem Cells in Veterinary Regenerative Therapy: Basic Physiology to Clinical Applications

2021 ◽  
Vol 16 ◽  
Author(s):  
Vikash Chandra ◽  
Pratheesh Mankuzhy ◽  
Taru Sharma G.
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Adult Stem Cells ◽  
Es Cells ◽  
Embryonic Stem ◽  
The Body ◽  
Ligament Injury ◽  
Repair System ◽  
Regenerative Therapy ◽  
Differentiation Potential

Background: The consistent, self-renewal capability and wide-ranging differentiation potential during specific physiologic conditions mark stem cells as a novel candidate not only for biomedical research and regenerative therapy but also as an alternative source in research related to life sciences. This vital and distinct characteristic of stem cells, enable them to offer unprecedented hope in treating many diseases and disorders, which are otherwise difficult to treat. Several efforts are still being undertaken to enhance the efficiency of MSCs for better therapeutic applications. Objective: In recent past several studies have been conducted regarding isolation of stem cells from diverse sources and are being used clinically in veterinary regenerative therapy. But till date only a few systemic studies are available. This study provides a comprehensive analysis of the findings from basic and applied research conducted in stem cell therapeutics with particular emphasis on animals. Result: On the basis of their sources, stem cells can be classified as adult or embryonic stem (ES) cells. Physiologically, the ES cells have capability to differentiate into all body cells and develop into normal adult organism; whereas, adult stem cells serve as repair system by restoring damaged tissues of the body. The adult stem cells referred as Mesenchymal stem cells (MSCs) can be derived from various adult body organs whereas embryos give rise to embryonic stem cells. MSCs, passes unique property of proliferation, trans-differentiation and secretion of important biomolecules to create microenvironment; which is immunosuppressive and stimulate native MSCs of damaged tissue. MSCs being immunocompromised cells can be used in autologous as well as in allogenic mode. Conclusion: In Veterinary therapeutics, MSCs equipped with engineering and pharmaceutical modifications offer a potentially candidate in the treatment of wound healing, nerve injury, bone/ligament injury etc. and also bear a great hope in improvement of udder health and milk production in animals.

scholarly journals Dynamics of Telomere Length and Telomerase Activity in the Human Fetal Liver at 5–12 Weeks of Gestation

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Khrystyna Sorochynska ◽  
Nataliia Sych ◽  
Alla Duda ◽  
Kateryna Kulebyakina ◽  
Dmytro Krasnienkov ◽  
...  
Keyword(s):  
Stem Cells ◽  
Telomere Length ◽  
Cellular Proliferation ◽  
Fetal Liver ◽  
Embryonic Stem ◽  
Telomerase Activity ◽  
Small Sample ◽  
Proliferative Potential ◽  
Differentiation Potential ◽  
Human Fetal Liver

Fetal stem cell- (FSC-) based therapy is a promising treatment option for many diseases. The differentiation potential of FSCs is greater than that in adult stem cells, and they are more tissue-specific and have lower immunogenicity and better intrinsic homing than embryonic ones. Embryonic stem cells have higher proliferative potential than FSCs but can cause teratomas. Therefore, an evaluation of this potential represents an important biomedical challenge. Since regulation of telomere length (TL) is one mechanism governing cellular proliferation, TL is a useful surrogate marker for cell replicative potential. The prenatal dynamics of TL, however, has never been comprehensively studied. In the present study, dynamics of TL and telomerase activity in the human fetal liver during 5–12 weeks of gestation is examined. Both TL and telomerase activity were positively correlated with week of gestation. For both parameters studied, the trend to increase was evident up to 10th week of gestation. After that, they reached a plateau and remained stable. These findings indicate that telomerase activity remains high during the fetal stage, suggesting high replicative capacity of FSCs and their considerable potential for transplantation therapies. These findings, however, are preliminary only due to small sample size and require further evaluation.

Sign in / Sign up

Export Citation Format

Share Document