scholarly journals Epigenetic Contribution of High-Mobility Group A Proteins to Stem Cell Properties

2018 ◽  
Vol 2018 ◽  
pp. 1-20 ◽  
Author(s):  
Vincenzo Giancotti ◽  
Natascha Bergamin ◽  
Palmina Cataldi ◽  
Claudio Rizzi

High-mobility group A (HMGA) proteins have been examined to understand their participation as structural epigenetic chromatin factors that confer stem-like properties to embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs), and cancer stem cells (CSCs). The function of HMGA was evaluated in conjunction with that of other epigenetic factors such as histones and microRNAs (miRs), taking into consideration the posttranscriptional modifications (PTMs) of histones (acetylation and methylation) and DNA methylation. HMGA proteins were coordinated or associated with histone and DNA modification and the expression of the factors related to pluripotency. CSCs showed remarkable differences compared with ESCs and iPSCs.

Reproduction ◽  
2013 ◽  
Vol 146 (6) ◽  
pp. 569-579 ◽  
Author(s):  
Anran Fan ◽  
Kuiying Ma ◽  
Xinglan An ◽  
Yu Ding ◽  
Peipei An ◽  
...  

TET1 is implicated in maintaining the pluripotency of embryonic stem cells. However, its precise effects on induced pluripotent stem cells (iPSCs), and particularly on porcine iPSCs (piPSCs), are not well defined. To investigate the role of TET1 in the pluripotency and differentiation of piPSCs, piPSCs were induced from porcine embryonic fibroblasts by overexpression ofPOU5F1(OCT4),SOX2,KLF4, andMYC(C-MYC). siRNAs targeting toTET1were used to transiently knockdown the expression ofTET1in piPSCs. Morphological abnormalities and loss of the undifferentiated state of piPSCs were observed in the piPSCs after the downregulation ofTET1. The effects ofTET1knockdown on the expression of key stem cell factors and differentiation markers were analyzed to gain insights into the molecular mechanisms underlying the phenomenon. The results revealed that knockdown ofTET1resulted in the downregulated expression of pluripotency-related genes, such asLEFTY2,KLF2, andSOX2, and the upregulated expression of differentiation-related genes includingPITX2,HAND1,GATA6, andLEF1. However,POU5F1,MYC,KLF4, andNANOGwere actually not downregulated. Further analysis showed that the methylation levels of the promoters forPOU5F1andMYCincreased significantly afterTET1downregulation, whereas there were no obvious changes in the promoters ofSOX2,KLF4, andNANOG. The methylation of the whole genome increased, while hydroxymethylation slightly declined. Taken together, these results suggest thatTET1may play important roles in the self-renewal of piPSCs and the maintenance of their characteristics by regulating the expression of genes and the DNA methylation.


2016 ◽  
Vol 113 (43) ◽  
pp. 12202-12207 ◽  
Author(s):  
Timothy Alexander Hore ◽  
Ferdinand von Meyenn ◽  
Mirunalini Ravichandran ◽  
Martin Bachman ◽  
Gabriella Ficz ◽  
...  

Epigenetic memory, in particular DNA methylation, is established during development in differentiating cells and must be erased to create naïve (induced) pluripotent stem cells. The ten-eleven translocation (TET) enzymes can catalyze the oxidation of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC) and further oxidized derivatives, thereby actively removing this memory. Nevertheless, the mechanism by which the TET enzymes are regulated, and the extent to which they can be manipulated, are poorly understood. Here we report that retinoic acid (RA) or retinol (vitamin A) and ascorbate (vitamin C) act as modulators of TET levels and activity. RA or retinol enhances 5hmC production in naïve embryonic stem cells by activation of TET2 and TET3 transcription, whereas ascorbate potentiates TET activity and 5hmC production through enhanced Fe2+ recycling, and not as a cofactor as reported previously. We find that both ascorbate and RA or retinol promote the derivation of induced pluripotent stem cells synergistically and enhance the erasure of epigenetic memory. This mechanistic insight has significance for the development of cell treatments for regenenerative medicine, and enhances our understanding of how intrinsic and extrinsic signals shape the epigenome.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Siti Razila Abdul Razak ◽  
Yukihiro Baba ◽  
Hiromitsu Nakauchi ◽  
Makoto Otsu ◽  
Sumiko Watanabe

MicroRNAs are differentially expressed in cells and regulate multiple biological processes. We have been analyzing comprehensive expression patterns of microRNA in human and mouse embryonic stem and induced pluripotent stem cells. We determined microRNAs specifically expressed in these pluripotent stem cells, and miR-142-3p is one of such microRNAs. miR-142-3p is expressed at higher levels in induced pluripotent stem cells relative to fibroblasts in mice. Level of expression of miR142-3p decreased during embryoid body formation from induced pluripotent stem cells. Loss-of-function analyses of miR-142-3p suggested that miR-142-3p plays roles in the proliferation and differentiation of induced pluripotent stem cells. CpG motifs were found in the 5′ genomic region of themiR-142-3p; they were highly methylated in fibroblasts, but not in undifferentiated induced pluripotent stem cells. Treating fibroblasts with 5-aza-2′-deoxycytidine increased the expression of miR-142-3p significantly and reduced methylation at the CpG sites, suggesting that the expression of miR-142-3p is suppressed by DNA methylation in fibroblasts. Luciferase analysis using various lengths of the 5′ genomic region of miR142-3p indicated that CpGs in the proximal enhancer region may play roles in suppressing the expression of miR-142-3p in fibroblasts.


2020 ◽  
Vol 15 (4) ◽  
pp. 301-307 ◽  
Author(s):  
Gaifang Wang ◽  
Maryam Farzaneh

Primary Ovarian Insufficiency (POI) is one of the main diseases causing female infertility that occurs in about 1% of women between 30-40 years of age. There are few effective methods for the treatment of women with POI. In the past few years, stem cell-based therapy as one of the most highly investigated new therapies has emerged as a promising strategy for the treatment of POI. Human pluripotent stem cells (hPSCs) can self-renew indefinitely and differentiate into any type of cell. Human Embryonic Stem Cells (hESCs) as a type of pluripotent stem cells are the most powerful candidate for the treatment of POI. Human-induced Pluripotent Stem Cells (hiPSCs) are derived from adult somatic cells by the treatment with exogenous defined factors to create an embryonic-like pluripotent state. Both hiPSCs and hESCs can proliferate and give rise to ectodermal, mesodermal, endodermal, and germ cell lineages. After ovarian stimulation, the number of available oocytes is limited and the yield of total oocytes with high quality is low. Therefore, a robust and reproducible in-vitro culture system that supports the differentiation of human oocytes from PSCs is necessary. Very few studies have focused on the derivation of oocyte-like cells from hiPSCs and the details of hPSCs differentiation into oocytes have not been fully investigated. Therefore, in this review, we focus on the differentiation potential of hPSCs into human oocyte-like cells.


2009 ◽  
Vol 1 (1) ◽  
pp. 76-82 ◽  
Author(s):  
Mark Denham ◽  
Jessie Leung ◽  
Cheryl Tay ◽  
Raymond C.B. Wong ◽  
Peter Donovan ◽  
...  

2021 ◽  
Vol 22 (9) ◽  
pp. 5011
Author(s):  
Daehwan Kim ◽  
Sangho Roh

Stem cell research is essential not only for the research and treatment of human diseases, but also for the genetic preservation and improvement of animals. Since embryonic stem cells (ESCs) were established in mice, substantial efforts have been made to establish true ESCs in many species. Although various culture conditions were used to establish ESCs in cattle, the capturing of true bovine ESCs (bESCs) has not been achieved. In this review, the difficulty of establishing bESCs with various culture conditions is described, and the characteristics of proprietary induced pluripotent stem cells and extended pluripotent stem cells are introduced. We conclude with a suggestion of a strategy for establishing true bESCs.


Author(s):  
Anja Trillhaase ◽  
Marlon Maertens ◽  
Zouhair Aherrahrou ◽  
Jeanette Erdmann

AbstractStem cell technology has been around for almost 30 years and in that time has grown into an enormous field. The stem cell technique progressed from the first successful isolation of mammalian embryonic stem cells (ESCs) in the 1990s, to the production of human induced-pluripotent stem cells (iPSCs) in the early 2000s, to finally culminate in the differentiation of pluripotent cells into highly specialized cell types, such as neurons, endothelial cells (ECs), cardiomyocytes, fibroblasts, and lung and intestinal cells, in the last decades. In recent times, we have attained a new height in stem cell research whereby we can produce 3D organoids derived from stem cells that more accurately mimic the in vivo environment. This review summarizes the development of stem cell research in the context of vascular research ranging from differentiation techniques of ECs and smooth muscle cells (SMCs) to the generation of vascularized 3D organoids. Furthermore, the different techniques are critically reviewed, and future applications of current 3D models are reported. Graphical abstract


2019 ◽  
Vol 8 (3) ◽  
pp. 288 ◽  
Author(s):  
Stephen Attwood ◽  
Michael Edel

The use of induced Pluripotent Stem Cells (iPSC) as a source of autologous tissues shows great promise in regenerative medicine. Nevertheless, several major challenges remain to be addressed before iPSC-derived cells can be used in therapy, and experience of their clinical use is extremely limited. In this review, the factors affecting the safe translation of iPSC to the clinic are considered, together with an account of efforts being made to overcome these issues. The review draws upon experiences with pluripotent stem-cell therapeutics, including clinical trials involving human embryonic stem cells and the widely transplanted mesenchymal stem cells. The discussion covers concerns relating to: (i) the reprogramming process; (ii) the detection and removal of incompletely differentiated and pluripotent cells from the resulting medicinal products; and (iii) genomic and epigenetic changes, and the evolutionary and selective processes occurring during culture expansion, associated with production of iPSC-therapeutics. In addition, (iv) methods for the practical culture-at-scale and standardization required for routine clinical use are considered. Finally, (v) the potential of iPSC in the treatment of human disease is evaluated in the light of what is known about the reprogramming process, the behavior of cells in culture, and the performance of iPSC in pre-clinical studies.


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