Maintenance of Pluripotent Stem Cells is Influenced by Ser/Thr Metabolism

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. SCI-43-SCI-43
Author(s):  
Lewis C. Cantley

Abstract Recent studies have suggested not only that stem cells have different metabolic requirements than terminally differentiated cells, but also that metabolic intermediates may play a role in the maintenance of stem cells. It has long been clear that changes in acetylation and methylation of histones, as well as methylation of DNA play critical roles in deciding cell fate. The availability of critical intermediates in metabolism, especially S-adenosylmethionine (SAM), acetyl-CoA, nicotinamide adenine dinucleotide (NAD) and a-ketoglutarate play critical roles in modulating acetylation and methylation of histones and methylation of DNA. In the course of evaluating an unusual requirement of threonine (Thr) for the growth of murine embryonic stem cells, we found that metabolism of Thr to glycine (Gly) and the subsequent use of the methyl group of Gly for converting homocysteine to methionine is critical for maintaining high levels of SAM and low levels of S-adenosyl-homocysteine. Importantly, depletion of Thr from the media resulted in decreased tri-methylation of histone H3 lysine-4 (H3K4me3), leading to slowed growth and increased differentiation. Thus, abundance of SAM appears to influence H3K4me3, providing a possible mechanism by which modulation of a metabolic pathway might influence stem cell fate. Demethylation of histones and DNA can also be controlled by metabolic intermediates. Mutated forms of isocitrate dehydrogenase 1 (IDH1) and IDH2 that drive acute myeloid leukemia (AML) and other cancers, produce an oncometabolite (2-hydrogyglutarate) that can compete with the a-ketoglutarate requirement for enzymes involved in hydroxy-methylation and subsequent demethylation of DNA and histones. Recent studies indicate that 2-hydroxyglutarate plays a role in blocking differentiation of cancer cells. These and other observations linking intermediates in metabolism to stem cell maintenance will be discussed. Disclosures Cantley: Agios Pharmaceuticals: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties.

Author(s):  
Srivathsa S. Magadi ◽  
Chrysanthi Voutyraki ◽  
Gerasimos Anagnostopoulos ◽  
Evanthia Zacharioudaki ◽  
Ioanna K. Poutakidou ◽  
...  

ABSTRACTNeural stem cells divide during embryogenesis and post embryonic development to generate the entire complement of neurons and glia in the nervous system of vertebrates and invertebrates. Studies of the mechanisms controlling the fine balance between neural stem cells and more differentiated progenitors have shown that in every asymmetric cell division progenitors send a Delta-Notch signal back to their sibling stem cells. Here we show that excessive activation of Notch or overexpression of its direct targets of the Hes family causes stem-cell hyperplasias in the Drosophila larval central nervous system, which can progress to malignant tumours after allografting to adult hosts. We combined transcriptomic data from these hyperplasias with chromatin occupancy data for Dpn, a Hes transcription factor, to identify genes regulated by Hes factors in this process. We show that the Notch/Hes axis represses a cohort of transcription factor genes. These are excluded from the stem cells and promote early differentiation steps, most likely by preventing the reversion of immature progenitors to a stem-cell fate. Our results suggest that Notch signalling sets up a network of mutually repressing stemness and anti-stemness transcription factors, which include Hes proteins and Zfh1, respectively. This mutual repression ensures robust transition to neuronal and glial differentiation and its perturbation can lead to malignant transformation.


2021 ◽  
Author(s):  
Lindy Jensen ◽  
Zsolt G. Venkei ◽  
George J. Watase ◽  
Bitarka Bisai ◽  
Scott Pletcher ◽  
...  

Tissue-specific stem cells maintain tissue homeostasis by providing a continuous supply of differentiated cells throughout the life of organisms. Differentiated/differentiating cells can revert back to a stem cell identity via dedifferentiation to help maintain the stem cell pool beyond the lifetime of individual stem cells. Although dedifferentiation is important to maintain the stem cell population, it is speculated to underlie tumorigenesis. Therefore, this process must be tightly controlled. Here we show that a translational regulator me31B plays a critical role in preventing excess dedifferentiation in the Drosophila male germline: in the absence of me31B, spermatogonia (SGs) dedifferentiate into germline stem cells (GSCs) at a dramatically elevated frequency. Our results show that the excess dedifferentiation is likely due to misregulation of nos, a key regulator of germ cell identity and GSC maintenance. Taken together, our data reveal negative regulation of dedifferentiation to balance stem cell maintenance with differentiation.


2008 ◽  
Vol 20 (9) ◽  
pp. 111
Author(s):  
J. C. Young ◽  
Y. Miyamoto ◽  
A. Major ◽  
V. L. Dias ◽  
D. A. Jans ◽  
...  

The importin (IMP) family of proteins mediates transport into the nucleus for many proteins larger than 40 kD. Through differential cargo recognition, IMPs regulate cellular events by controlling nuclear access of transcription factors and chromatin remodelling agents. During spermatogenesis, many IMPs change expression and localisation in a manner concordant with specific stages of spermatogenic development. To assess the potential role of IMPs in the transition between the stem cell and subsequent differentiation, we undertook analysis of the expression and subcellular localisation of several key murine IMPs in both pluripotent embryonic stem cells (mESCs) and embryoid bodies (EBs). All of the IMPs analysed (IMPα2, 3, 4, IMPβ1 and IMP5) were detected in undifferentiated mESCs by immunofluorescence, and each exhibited distinctive nucleocytoplasmic distribution patterns. Subcellular localisation of most IMPs altered after 10 days of mESC differentiation as EBs. This was paralleled by changes in the mRNA levels of IMPα1–4, IMPα6, IMPβ1 and IMP5, concomitant with alterations in the expression level of the pluripotency marker, Oct3/4. Reducing IMP-dependent nuclear import through overexpression of specific dominant-negative IMP constructs led to alterations in import or production of Oct3/4 protein, depending on the specific IMP. These findings indicate that IMPs may play very specific but distinct roles in cell fate choice between maintenance of pluri/multipotency and commitment to differentiation in ESCs and potentially in spermatogenesis or other organs that contain stem cells.


2019 ◽  
Vol 51 (11) ◽  
pp. 1-12 ◽  
Author(s):  
June Sung Bae ◽  
Sun Mi Kim ◽  
Yoon Jeon ◽  
Juyeon Sim ◽  
Ji Yun Jang ◽  
...  

AbstractThe Hippo pathway plays a crucial role in cell proliferation and apoptosis and can regulate stem cell maintenance and embryonic development. MOB kinase activators 1A and 1B (Mob1a/b) are key components of the Hippo pathway, whose homozygous deletion in mice causes early embryonic lethality at the preimplantation stage. To investigate the role of Mob1a/b in stem cell maintenance and differentiation, an embryonic stem cell (ESC) clone in which Mob1a/b could be conditionally depleted was generated and characterized. Although Mob1a/b depletion did not affect the stemness or proliferation of mouse ESCs, this depletion caused defects in differentiation into the three germ layers. Yap knockdown rescued the in vitro and in vivo defects in differentiation caused by Mob1a/b depletion, suggesting that differentiation defects caused by Mob1a/b depletion were Yap-dependent. In teratoma experiments, Yap knockdown in Mob1a/b-depleted ESCs partially restored defects in differentiation, indicating that hyperactivation of Taz, another effector of the Hippo pathway, inhibited differentiation into the three germ layers. Taken together, these results suggest that Mob1a/b or Hippo signaling plays a critical role in the differentiation of mouse ESCs into the three germ layers, which is dependent on Yap. These close relationship of the Hippo pathway with the differentiation of stem cells supports its potential as a therapeutic target in regenerative medicine.


eLife ◽  
2013 ◽  
Vol 2 ◽  
Author(s):  
Ricardo Antonio Rosselló ◽  
Chun-Chun Chen ◽  
Rui Dai ◽  
Jason T Howard ◽  
Ute Hochgeschwender ◽  
...  

Cells are fundamental units of life, but little is known about evolution of cell states. Induced pluripotent stem cells (iPSCs) are once differentiated cells that have been re-programmed to an embryonic stem cell-like state, providing a powerful platform for biology and medicine. However, they have been limited to a few mammalian species. Here we found that a set of four mammalian transcription factor genes used to generate iPSCs in mouse and humans can induce a partially reprogrammed pluripotent stem cell (PRPSCs) state in vertebrate and invertebrate model organisms, in mammals, birds, fish, and fly, which span 550 million years from a common ancestor. These findings are one of the first to show cross-lineage stem cell-like induction, and to generate pluripotent-like cells for several of these species with in vivo chimeras. We suggest that the stem-cell state may be highly conserved across a wide phylogenetic range.


2017 ◽  
Vol 37 (7) ◽  
pp. 647-660 ◽  
Author(s):  
Saradaprasan Muduli ◽  
Li-Hua Chen ◽  
Meng-Pei Li ◽  
Zhao-wen Heish ◽  
Cheng-Hui Liu ◽  
...  

Abstract The physical characteristics of cell culture materials, such as their elasticity, affect stem cell fate with respect to cell proliferation and differentiation. We systematically investigated the morphologies and characteristics of several stem cell types, including human amniotic-derived stem cells, human hematopoietic stem cells, human induced pluripotent stem (iPS) cells, and embryonic stem (ES) cells on poly(vinyl alcohol) (PVA) hydrogels immobilized with and without extracellular matrix-derived oligopeptide. Human ES cells did not adhere well to soft PVA hydrogels immobilized with oligovitronectin, whereas they did adhere well to PVA hydrogel dishes with elasticities greater than 15 kPa. These results indicate that biomaterials such as PVA hydrogels should be designed to possess minimum elasticity to facilitate human ES cell attachment. PVA hydrogels immobilized with and without extracellular matrix-derived oligopeptides are excellent candidates of cell culture biomaterials for investigations into how cell culture biomaterial elasticity affects stem cell culture and differentiation.


2015 ◽  
Vol 1 (10) ◽  
pp. e1500723 ◽  
Author(s):  
Oleg Fedorov ◽  
Josefina Castex ◽  
Cynthia Tallant ◽  
Dafydd R. Owen ◽  
Sarah Martin ◽  
...  

Mammalian SWI/SNF [also called Brg/Brahma-associated factors (BAFs)] are evolutionarily conserved chromatin-remodeling complexes regulating gene transcription programs during development and stem cell differentiation. BAF complexes contain an ATP (adenosine 5′-triphosphate)–driven remodeling enzyme (either BRG1 or BRM) and multiple protein interaction domains including bromodomains, an evolutionary conserved acetyl lysine–dependent protein interaction motif that recruits transcriptional regulators to acetylated chromatin. We report a potent and cell active protein interaction inhibitor, PFI-3, that selectively binds to essential BAF bromodomains. The high specificity of PFI-3 was achieved on the basis of a novel binding mode of a salicylic acid head group that led to the replacement of water molecules typically maintained in other bromodomain inhibitor complexes. We show that exposure of embryonic stem cells to PFI-3 led to deprivation of stemness and deregulated lineage specification. Furthermore, differentiation of trophoblast stem cells in the presence of PFI-3 was markedly enhanced. The data present a key function of BAF bromodomains in stem cell maintenance and differentiation, introducing a novel versatile chemical probe for studies on acetylation-dependent cellular processes controlled by BAF remodeling complexes.


2018 ◽  
Author(s):  
Naomi Moris ◽  
Shlomit Edri ◽  
Denis Seyres ◽  
Rashmi Kulkarni ◽  
Ana Filipa Domingues ◽  
...  

ABSTRACTCell fate transitions in mammalian stem cell systems have often been associated with transcriptional heterogeneity, however existing data have failed to establish a functional or mechanistic link between the two phenomena. Experiments in unicellular organisms support the notion that transcriptional heterogeneity can be used to facilitate adaptability to environmental changes and have identified conserved chromatin-associated factors that modulate levels of transcriptional noise. Herein, we show destabilisation of pluripotency-associated gene regulatory networks through increased transcriptional heterogeneity of mouse embryonic stem cells in which paradigmatic histone acetyl-transferase, and candidate noise modulator, Kat2a (yeast orthologue Gcn5) has been inhibited. Functionally, network destabilisation associates with reduced pluripotency and accelerated mesendodermal differentiation, with increased probability of transitions into lineage commitment. Thus, we functionally link transcriptional heterogeneity to cell fate transitions through manipulation of the histone acetylation landscape of mouse embryonic stem cells and establish a general paradigm that could be exploited in other normal and malignant stem cell fate transitions.


eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Kirsty ML Mackinlay ◽  
Bailey AT Weatherbee ◽  
Viviane Souza Rosa ◽  
Charlotte E Handford ◽  
George Hudson ◽  
...  

Human embryogenesis entails complex signalling interactions between embryonic and extra-embryonic cells. However, how extra-embryonic cells direct morphogenesis within the human embryo remains largely unknown due to a lack of relevant stem cell models. Here, we have established conditions to differentiate human pluripotent stem cells (hPSCs) into yolk sac-like cells (YSLCs) that resemble the post-implantation human hypoblast molecularly and functionally. YSLCs induce the expression of pluripotency and anterior ectoderm markers in human embryonic stem cells (hESCs) at the expense of mesoderm and endoderm markers. This activity is mediated by the release of BMP and WNT signalling pathway inhibitors, and, therefore, resembles the functioning of the anterior visceral endoderm signalling centre of the mouse embryo, which establishes the anterior-posterior axis. Our results implicate the yolk sac in epiblast cell fate specification in the human embryo and propose YSLCs as a tool for studying post-implantation human embryo development in vitro.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Yuanjie Ding ◽  
Yuanchun Yao ◽  
Xingmu Gong ◽  
Qi Zhuo ◽  
Jinhua Chen ◽  
...  

AbstractThe Jumonji domain-containing protein-3 (JMJD3) is a histone demethylase that regulates the trimethylation of histone H3 on lysine 27 (H3K27me3). H3K27me3 is an important epigenetic event associated with transcriptional silencing. JMJD3 has been studied extensively in immune diseases, cancer, and tumor development. There is a comprehensive epigenetic transformation during the transition of embryonic stem cells (ESCs) into specialized cells or the reprogramming of somatic cells to induced pluripotent stem cells (iPSCs). Recent studies have illustrated that JMJD3 plays a major role in cell fate determination of pluripotent and multipotent stem cells (MSCs). JMJD3 has been found to enhance self-renewal ability and reduce the differentiation capacity of ESCs and MSCs. In this review, we will focus on the recent advances of JMJD3 function in stem cell fate.


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