scholarly journals Loss of Mob1a/b impairs the differentiation of mouse embryonic stem cells into the three germ layer lineages

2019 ◽  
Vol 51 (11) ◽  
pp. 1-12 ◽  
Author(s):  
June Sung Bae ◽  
Sun Mi Kim ◽  
Yoon Jeon ◽  
Juyeon Sim ◽  
Ji Yun Jang ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Hippo Pathway ◽  
Critical Role ◽  
Embryonic Stem ◽  
Mouse Escs ◽  
Germ Layers ◽  
Stem Cell Maintenance ◽  
The Hippo Pathway ◽  
Cell Maintenance

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.

scholarly journals Selective targeting of the BRG/PB1 bromodomains impairs embryonic and trophoblast stem cell maintenance

2015 ◽  
Vol 1 (10) ◽  
pp. e1500723 ◽  
Author(s):  
Oleg Fedorov ◽  
Josefina Castex ◽  
Cynthia Tallant ◽  
Dafydd R. Owen ◽  
Sarah Martin ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Protein Interaction ◽  
Embryonic Stem ◽  
High Specificity ◽  
Stem Cell Differentiation ◽  
Head Group ◽  
Stem Cell Maintenance ◽  
Trophoblast Stem ◽  
Cell Maintenance

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.

scholarly journals The Role of Ubiquitination in Regulating Embryonic Stem Cell Maintenance and Cancer Development

2019 ◽  
Vol 20 (11) ◽  
pp. 2667 ◽  
Author(s):  
Dian Wang ◽  
Fan Bu ◽  
Weiwei Zhang
Keyword(s):  
Stem Cell ◽  
Embryonic Stem Cell ◽  
Cancer Biology ◽  
Embryonic Stem ◽  
Developmental Defects ◽  
Stem Cell Maintenance ◽  
Substrate Protein ◽  
Cellular Events ◽  
Ubiquitin Conjugating Enzymes ◽  
Cell Maintenance

Ubiquitination regulates nearly every aspect of cellular events in eukaryotes. It modifies intracellular proteins with 76-amino acid polypeptide ubiquitin (Ub) and destines them for proteolysis or activity alteration. Ubiquitination is generally achieved by a tri-enzyme machinery involving ubiquitin activating enzymes (E1), ubiquitin conjugating enzymes (E2) and ubiquitin ligases (E3). E1 activates Ub and transfers it to the active cysteine site of E2 via a transesterification reaction. E3 coordinates with E2 to mediate isopeptide bond formation between Ub and substrate protein. The E1-E2-E3 cascade can create diverse types of Ub modifications, hence effecting distinct outcomes on the substrate proteins. Dysregulation of ubiquitination results in severe consequences and human diseases. There include cancers, developmental defects and immune disorders. In this review, we provide an overview of the ubiquitination machinery and discuss the recent progresses in the ubiquitination-mediated regulation of embryonic stem cell maintenance and cancer biology.

scholarly journals Maintenance of high levels of pluripotent hematopoietic stem cells in vitro: effect of stromal cells and c-kit

Blood ◽  
1993 ◽  
Vol 81 (2) ◽  
pp. 365-372 ◽  
Author(s):  
JP Wineman ◽  
S Nishikawa ◽  
CE Muller-Sieburg
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Line ◽  
Stromal Cells ◽  
Stromal Cell ◽  
Hematopoietic Stem ◽  
Stem Cell Maintenance ◽  
Stromal Cell Line ◽  
Cell Maintenance

We show here that mouse pluripotent hematopoietic stem cells can be maintained in vitro on stroma for at least 3 weeks at levels close to those found in bone marrow. The extent of stem cell maintenance is affected by the nature of the stromal cells. The stromal cell line S17 supported stem cells significantly better than heterogeneous, primary stromal layers or the stromal cell line Strofl-1. Stem cells cultured on S17 repopulated all hematopoietic lineages in marrow-ablated hosts for at least 10 months, indicating that this culture system maintained primitive stem cells with extensive proliferative capacity. Furthermore, we demonstrate that, while pluripotent stem cells express c-kit, this receptor appears to play only a minor role in stem cell maintenance in vitro. The addition of an antibody that blocks the interaction of c-kit with its ligand essentially abrogated myelopoiesis in cultures. However, the level of stem cells in antibody-treated cultures was similar to that found in untreated cultures. Thus, it seems likely that the maintenance of primitive stem cells in vitro depends on yet unidentified stromal cell-derived factor(s).

scholarly journals me31B regulates stem cell homeostasis by preventing excess dedifferentiation in the Drosophila male germline

2021 ◽  
Author(s):  
Lindy Jensen ◽  
Zsolt G. Venkei ◽  
George J. Watase ◽  
Bitarka Bisai ◽  
Scott Pletcher ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Critical Role ◽  
Stem Cell Population ◽  
Germline Stem Cells ◽  
Cell Identity ◽  
Stem Cell Maintenance ◽  
Differentiated Cells ◽  
Male Germline ◽  
Elevated Frequency

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.

scholarly journals Positively Correlated CD47 Activation and Autophagy in Umbilical Cord Blood-Derived Mesenchymal Stem Cells during Senescence

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Gee-Hye Kim ◽  
Yun Kyung Bae ◽  
Ji Hye Kwon ◽  
Miyeon Kim ◽  
Soo Jin Choi ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Stem Cell ◽  
Cell Growth ◽  
Cell Therapy ◽  
Critical Role ◽  
Therapeutic Effects ◽  
Stem Cell Maintenance ◽  
Selection Of

Autophagy plays a critical role in stem cell maintenance and is related to cell growth and cellular senescence. It is important to find a quality-control marker for predicting senescent cells. This study verified that CD47 could be a candidate to select efficient mesenchymal stem cells (MSCs) to enhance the therapeutic effects of stem cell therapy by analyzing the antibody surface array. CD47 expression was significantly decreased during the expansion of MSCs in vitro ( p < 0.01 ), with decreased CD47 expression correlated with accelerated senescence phenotype, which affected cell growth. UCB-MSCs transfected with CD47 siRNA significantly triggered the downregulation of pRB and upregulation of pp38, which are senescence-related markers. Additionally, autophagy-related markers, ATG5, ATG12, Beclin1, and LC3B, revealed significant downregulation with CD47 siRNA transfection. Furthermore, autophagy flux following treatment with an autophagy inducer, rapamycin, has shown that CD47 is a key player in autophagy and senescence to maintain and regulate the growth of MSCs, suggesting that CD47 may be a critical key marker for the selection of effective stem cells in cell therapy.

Abstract 2621: OLIG2 regulates stem cell maintenance and cell cycle in glioma stem cells

2019 ◽  
Author(s):  
Norihiko Saito ◽  
Nozomi Hirai ◽  
Kazuya Aoki ◽  
Satoshi Fujita ◽  
Haruo Nakayama ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Stem Cell ◽  
Glioma Stem Cells ◽  
Stem Cell Maintenance ◽  
Cell Maintenance
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