scholarly journals Disruption of RING and PHD Domains of TRIM28 Evokes Differentiation in Human iPSCs

Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1933
Author(s):  
Sylwia Mazurek ◽  
Urszula Oleksiewicz ◽  
Patrycja Czerwińska ◽  
Joanna Wróblewska ◽  
Marta Klimczak ◽  
...  

TRIM28, a multi-domain protein, is crucial in the development of mouse embryos and the maintenance of embryonic stem cells’ (ESC) self-renewal potential. As the epigenetic factor modulating chromatin structure, TRIM28 regulates the expression of numerous genes and is associated with progression and poor prognosis in many types of cancer. Because of many similarities between highly dedifferentiated cancer cells and normal pluripotent stem cells, we applied human induced pluripotent stem cells (hiPSC) as a model for stemness studies. For the first time in hiPSC, we analyzed the function of individual TRIM28 domains. Here we demonstrate the essential role of a really interesting new gene (RING) domain and plant homeodomain (PHD) in regulating pluripotency maintenance and self-renewal capacity of hiPSC. Our data indicate that mutation within the RING or PHD domain leads to the loss of stem cell phenotypes and downregulation of the FGF signaling. Moreover, impairment of RING or PHD domain results in decreased proliferation and impedes embryoid body formation. In opposition to previous data indicating the impact of phosphorylation on TRIM28 function, our data suggest that TRIM28 phosphorylation does not significantly affect the pluripotency and self-renewal maintenance of hiPSC. Of note, iPSC with disrupted RING and PHD functions display downregulation of genes associated with tumor metastasis, which are considered important targets in cancer treatment. Our data suggest the potential use of RING and PHD domains of TRIM28 as targets in cancer therapy.

2013 ◽  
Vol 25 (1) ◽  
pp. 301
Author(s):  
A. R. Fan ◽  
K. Y. Ma ◽  
T. C. Zhao ◽  
P. P. An ◽  
B. Tang ◽  
...  

It was recently found that the ten-eleven-translocation (TET) family of Fe(II) and 2-oxoglutarate-dependent enzymes (Tet1/2/3) can oxidize 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), and thus promotes active demethylation of genomes. Tet1 is highly expressed in mouse embryonic stem cells (mESC) and has been demonstrated to involve in mESC maintenance. Here we used small interference RNA (siRNA) to transiently knockdown expression of Tet1 in porcine induced pluripotent stem cells (iPSC) in order to identify its functions. The fetal fibroblasts were isolated from a 30-day-old porcine fetus and induced into iPSC with defined transcription factors, namely Oct-4, Sox-2, Klf-4, and C-myc. The colonies appeared on Day 12 and were picked up on Day 14. These colonies had normal ES-like morphology and alkaline phosphatase activity. Specifically, they were positively stained for pluripotency-specific markers, including Oct4, Sox2, Nanog, Rex1, and SSEA1. When cultured in vitro, the cells formed embryoid bodies (EB), and all 3 germ layer markers (endoderm: AFP, alphaAT; mesoderm: BMP4, Enolase; ectoderm: GFAP, Neurod) were detected positively in EB. For siRNA transfections, iPSC from the colonies were transfected with 40 pmol of siRNA and 2 µL of Lipofectamine 2000 in 1 well of a 24-well plate. After transfection, iPSC were subjected to fluorescence-activated cell sorting to determine the fraction of FAM-positive cells in order to confirm transfection efficiency; the percentage of positive cells reached 48 ± 4.96. We observed obvious knockdown of Tet1 after short-term transfection of siRNA, and the knockdown efficiency was confirmed using qRT-PCR and immunofluorescence staining. Notably, knockdown of Tet1 resulted in morphological abnormality and loss of undifferentiated state of porcine iPSC. However, no obvious morphological changes were observed in the negative control (transfected with nonsense-siRNA), positive control (transfected with GAPDH-siRNA), or mock control (transfected with DEPC-treated water). To gain insight into the molecular mechanism underlying the self-renewal defect, we analysed the effects of Tet1 knockdown on the expression of key stem cell factors and differentiation markers of different embryonic layers using qRT-PCR. We found that knockdown of Tet1 resulted in downregulated expression of pluripotency-related genes, such as Lefty-2, Klf-2, and Sox-2 (the expression ratios of post-transfection to pre-transfection were 0.31 ± 0.21, 0.48 ± 0.072, and 0.65 ± 0.046, respectively), and upregulated expression of differentiation-related genes, including Pitx-2, Hand-1, Gata-6, and Lef-1 (the expression ratios of post-transfection to pre-transfection were 4.35 ± 1.36, 2.56 ± 0.68, 2.91 ± 1.47, and 2.33 ± 1.11, respectively). However, Oct-4, C-myc, Klf-4, and Nanog were not downregulated (the expression ratios of post-transfection to pre-transfection were 0.91 ± 0.15, 1.12 ± 0.26, 1.15 ± 0.21, and 1.08 ± 0.08, respectively). Taken together, Tet1 plays important roles in porcine iPSC self-renewal and characterization maintenance. This study was financed by National Basic Research Program of China (NO.2009CB941001).


2011 ◽  
Vol 434 (1) ◽  
pp. 25-35 ◽  
Author(s):  
Cheryl Dambrot ◽  
Robert Passier ◽  
Douwe Atsma ◽  
Christine L. Mummery

More than 10 years after their first isolation, human embryonic stem cells are finally ‘coming of age’ in research and biotechnology applications as protocols for their differentiation and undifferentiated expansion in culture become robust and scalable, and validated commercial reagents become available. Production of human cardiomyocytes is now feasible on a daily basis for many laboratories with tissue culture expertise. An additional recent surge of interest resulting from the first production of human iPSCs (induced pluripotent stem cells) from somatic cells of patients now makes these technologies of even greater importance since it is likely that (genetic) cardiac disease phenotypes can be captured in the cardiac derivatives of these cells. Although cell therapy based on replacing cardiomyocytes lost or dysfunctional owing to cardiac disease are probably as far away as ever, biotechnology and pharmaceutical applications in safety pharmacology and drug discovery will probably impact this clinical area in the very near future. In the present paper, we review the cutting edge of this exciting area of translational research.


2020 ◽  
Vol In Press (In Press) ◽  
Author(s):  
Alice Sabet ◽  
Negar Azarpira ◽  
Saeid Ghavami ◽  
Leila Kohan

Background: Autophagy is a vital cell survival mechanism that authorizes cells to assort to metabolic stress and is essential for the development and maintenance of cellular and tissue homeostasis, as well as the prevention of human disease. It has also been shown that autophagy plays a significant role in the development and differentiation of stem cells, as well as induced pluripotent stem cells (iPSCs). Objectives: The present study aimed to examine the mRNA expression of the ATG5 gene, one of the key markers of autophagy in human iPSCs (hiPSCs) during endoderm induction. Methods: In this study, we cultured the human iPSC line (R1-hiPSC1) on mitomycin-C, inactivated mouse embryonic fibroblasts (MEF) layer, and used hanging drop protocol to generate embryoid body (EB) and expose differentiation. The Real-time PCR method was used to examine the mRNA expression level of ATG5 in hiPSC during endoderm induction. Results: Our results demonstrated the high mRNA expression of ATG5 in the MEI stage, which shows the high rate of autophagy in MEI days rather than the other stages of differentiation. Conclusions: The modification of ATG5 gene expression within hiPSC during endoderm induction shows the importance of autophagy assessments in hiPSC differentiation. Therefore, subsequent studies are needed to clarify the details of autophagy effects on hiPSC differentiation.


2011 ◽  
Vol 268-270 ◽  
pp. 835-837
Author(s):  
De Wu Liu ◽  
Yong Tie Li ◽  
De Ming Liu ◽  
Pu Ning

Human induced pluripotent stem cells is promising for regenerative medicine and tissue engineering. In this chapter, we focus on the culture and characteristics of human induced pluripotent stem cells. The induced pluripotent stem cells were plated on murine embryonic fibroblast feeder cells and expanded in human embryonic stem cells media contained basic fibroblast growth factor. The cells were passaged by collagenase IV digestion method and observed under invert microscope. The expression of alkaline phosphatase was detected by immunocytochemistry. The cultured induced pluripotent stem cells grew well and stability with similar characteristics of human embryonic stem cells. These cells also expressed alkaline phosphatase. They formed embryoid body in feeder-free and suspension culture conditions. The results provide an experimental basis for improvement of induction study and further application to generate patient-specific induced pluripotent stem cells.


2010 ◽  
Vol 298 (3) ◽  
pp. C486-C495 ◽  
Author(s):  
Peng Jiang ◽  
Stephanie N. Rushing ◽  
Chi-wing Kong ◽  
Jidong Fu ◽  
Deborah Kuo-Ti Lieu ◽  
...  

Human embryonic stem cells (hESCs) can self-renew while maintaining their pluripotency. Direct reprogramming of adult somatic cells to induced pluripotent stem cells (iPSCs) has been reported. Although hESCs and human iPSCs have been shown to share a number of similarities, such basic properties as the electrophysiology of iPSCs have not been explored. Previously, we reported that several specialized ion channels are functionally expressed in hESCs. Using transcriptomic analyses as a guide, we observed tetraethylammonium (TEA)-sensitive (IC50 = 3.3 ± 2.7 mM) delayed rectifier K+ currents ( IKDR) in 105 of 110 single iPSCs (15.4 ± 0.9 pF). IKDR in iPSCs displayed a current density of 7.6 ± 3.8 pA/pF at +40 mV. The voltage for 50% activation ( V1/2) was −7.9 ± 2.0 mV, slope factor k = 9.1 ± 1.5. However, Ca2+-activated K+ current ( IKCa), hyperpolarization-activated pacemaker current ( If), and voltage-gated sodium channel (NaV) and voltage-gated calcium channel (CaV) currents could not be measured. TEA inhibited iPSC proliferation (EC50 = 7.8 ± 1.2 mM) and viability (EC50 = 5.5 ± 1.0 mM). By contrast, 4-aminopyridine (4-AP) inhibited viability (EC50 = 4.5 ± 0.5 mM) but had less effect on proliferation (EC50 = 0.9 ± 0.5 mM). Cell cycle analysis further revealed that K+ channel blockers inhibited proliferation primarily by arresting the mitotic phase. TEA and 4-AP had no effect on iPSC differentiation as gauged by ability to form embryoid bodies and expression of germ layer markers after induction of differentiation. Neither iberiotoxin nor apamin had any function effects, consistent with the lack of IKCa in iPSCs. Our results reveal further differences and similarities between human iPSCs and hESCs. A better understanding of the basic biology of iPSCs may facilitate their ultimate clinical application.


2020 ◽  
Author(s):  
G. Telliam ◽  
O. Féraud ◽  
S. Baykal-Köse ◽  
F. Griscelli ◽  
J. Imeri ◽  
...  

ABSTRACTHemangioblasts derived from mesodermal lineage are the earliest precursors of hematopoietic stem cells and endothelial cells. Embryonic stem cells (ESC) and induced pluripotent stem cells (iPSC) are the only experimental systems in which these cells can be assayed and quantified. We show here using CML-derived iPSC and blast-cell colony forming (Bl-CFC) assays that hemangioblasts are highly expanded in CML derived iPSC as compared to human H1-ESC-derived hemangioblasts. BCR-ABL signaling pathway is intact in these cells with evidence of CRK-L phosphorylation which is reduced by the use of Imatinib. Hematopoietic progenitor assays generated using blast-CFC demonstrates also a highly increased hematopoietic progenitor potential of these cells as compared to H1-ESC. The same results were also obtained using hematopoietic progenitor assays via embryoid body formation. In CML iPSC, we have also found a significant reduction of Aryl Hydrocarbon Receptor (AHR) expression which is involved in hematopoietic quiescence. Further inhibition of AHR using StemRegenin (SR1), an AHR antagonist, led to an increase of blast-cell colonies in CML iPSC whereas the use of an AHR agonist inhibited blast cell colonies. Thus, our results show for the first time, the possibility of establishment of a myeloproliferative phenotype using patient-derived iPSC and the presence of a major expansion hemangioblast compartment and derived hematopoietic progenitors in this context. They also suggest that the AHR signaling pathway could represent a novel druggable target in CML.


2020 ◽  
Vol 10 (24) ◽  
pp. 8861
Author(s):  
Worawalan Samruan ◽  
Nathalie Beaujean ◽  
Marielle Afanassieff

Pluripotent stem cells (PSCs) possess the following two main properties: self-renewal and pluripotency. Self-renewal is defined as the ability to proliferate in an undifferentiated state and pluripotency as the capacity to differentiate into cells of the three germ layers, i.e., ectoderm, mesoderm, and endoderm. PSCs are derived from early embryos as embryonic stem cells (ESCs) or are produced by reprogramming somatic cells into induced pluripotent stem cells (iPSCs). In mice, PSCs can be stabilized into two states of pluripotency, namely naive and primed. Naive and primed PSCs notably differ by their ability to colonize a host blastocyst to produce germline-competent chimeras; hence, naive PSCs are valuable for transgenesis, whereas primed PSCs are not. Thanks to its physiological and developmental peculiarities similar to those of primates, the rabbit is an interesting animal model for studying human diseases and early embryonic development. Both ESCs and iPSCs have been described in rabbits. They self-renew in the primed state of pluripotency and, therefore, cannot be used for transgenesis. This review presents the available data on the pluripotent state and the chimeric ability of these rabbit PSCs. It also examines the potential barriers that compromise their intended use as producers of germline-competent chimeras and proposes possible alternatives to exploit them for transgenesis.


2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Pengfei Ji ◽  
Sasicha Manupipatpong ◽  
Nina Xie ◽  
Yujing Li

Possessing the ability of self-renewal with immortalization and potential for differentiation into different cell types, stem cells, particularly embryonic stem cells (ESC), have attracted significant attention since their discovery. As ESC research has played an essential role in developing our understanding of the mechanisms underlying reproduction, development, and cell (de)differentiation, significant efforts have been made in the biomedical study of ESC in recent decades. However, such studies of ESC have been hampered by the ethical issues and technological challenges surrounding them, therefore dramatically inhibiting the potential applications of ESC in basic biomedical studies and clinical medicine. Induced pluripotent stem cells (iPSCs), generated from the reprogrammed somatic cells, share similar characteristics including but not limited to the morphology and growth of ESC, self-renewal, and potential differentiation into various cell types. The discovery of the iPSC, unhindered by the aforementioned limitations of ESC, introduces a viable alternative to ESC. More importantly, the applications of iPSC in the development of disease models such as neurodegenerative disorders greatly enhance our understanding of the pathogenesis of such diseases and also facilitate the development of clinical therapeutic strategies using iPSC generated from patient somatic cells to avoid an immune rejection. In this review, we highlight the advances in iPSCs generation methods as well as the mechanisms behind their reprogramming. We also discuss future perspectives for the development of iPSC generation methods with higher efficiency and safety.


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