scholarly journals Non-canonical function of FIP200 is required for neural stem cell maintenance and differentiation by limiting TBK1 activation and p62 aggregate formation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hang Liu ◽  
Chenran Wang ◽  
Fei Yi ◽  
Syn Yeo ◽  
Michael Haas ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Neural Stem Cell ◽  
Kinase Activity ◽  
Aggregate Formation ◽  
Canonical Function ◽  
Stem Cell Maintenance ◽  
Autophagy Gene ◽  
Cell Maintenance

AbstractFIP200 is an essential autophagy gene implicated in the regulation of postnatal neural progenitor/stem cells (NSCs). However, the contribution of FIP200’s canonical-autophagy function and its non-canonical functions to postnatal NSC maintenance remains unclear. Utilizing a recently generated Fip200-4A allele that specifically impairs FIP200’s canonical-autophagy function, we found that non-canonical functions of FIP200 was required for regulation of mouse NSC maintenance and neurogenesis in vivo. Ablating the non-canonical functions of FIP200, but not its autophagy function, increased TBK1 activation and p62 phosphorylation at S403 in NSCs. Phosphorylation of p62 was dependent on TBK1 kinase activity and increased the propensity of p62 aggregate formation specifically in FIP200-null NSCs. Accordingly, inhibition of TBK1 by amlexanox reduced p62 aggregates and restored NSC maintenance and differentiation in Fip200hGFAP cKO mice. These results reveal a mechanism for the non-canonical functions of FIP200 in NSC maintenance and differentiation by limiting TBK1 activation and subsequently, p62 aggregate formation.

scholarly journals Mi-2/NuRD complex protects stem cell progeny from mitogenic Notch signaling

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Evanthia Zacharioudaki ◽  
Julia Falo Sanjuan ◽  
Sarah Bray
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Notch Signaling ◽  
Neural Stem Cell ◽  
Target Gene ◽  
Notch Signalling ◽  
Nurd Complex ◽  
Stem Cell Maintenance ◽  
Cell Maintenance ◽  
Mitogenic Signal

To progress towards differentiation, progeny of stem cells need to extinguish expression of stem-cell maintenance genes. Failures in such mechanisms can drive tumorigenesis. In Drosophila neural stem cell (NSC) lineages, excessive Notch signalling results in supernumerary NSCs causing hyperplasia. However, onset of hyperplasia is considerably delayed implying there are mechanisms that resist the mitogenic signal. Monitoring the live expression of a Notch target gene, E(spl)mγ, revealed that normal attenuation is still initiated in the presence of excess Notch activity so that re-emergence of NSC properties occurs only in older progeny. Screening for factors responsible, we found that depletion of Mi-2/NuRD ATP remodeling complex dramatically enhanced Notch-induced hyperplasia. Under these conditions, E(spl)mγ was no longer extinguished in NSC progeny. We propose that Mi-2 is required for decommissioning stem-cell enhancers in their progeny, enabling the switch towards more differentiated fates and rendering them insensitive to mitogenic factors such as Notch.

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).

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

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 Human Cytomegalovirus IE2 Protein Disturbs Brain Development by the Dysregulation of Neural Stem Cell Maintenance and the Polarization of Migrating Neurons

2017 ◽  
Vol 91 (17) ◽  
Author(s):  
Dasol Han ◽  
Sung-Hyun Byun ◽  
Juwan Kim ◽  
Mookwang Kwon ◽  
Samuel J. Pleasure ◽  
...  
Keyword(s):  
Stem Cell ◽  
Brain Development ◽  
Progenitor Cells ◽  
Neural Stem Cell ◽  
Human Cytomegalovirus ◽  
Neural Progenitor Cells ◽  
Hcmv Infection ◽  
Stem Cell Maintenance ◽  
Cell Maintenance

ABSTRACT Despite the high incidence of severe defects in the central nervous system caused by human cytomegalovirus (HCMV) congenital infection, the mechanism of HCMV neuropathogenesis and the roles of individual viral genes have not yet been fully determined. In this study, we show that the immediate-early 2 (IE2) protein may play a key role in HCMV-caused neurodevelopmental disorders. IE2-transduced neural progenitor cells gave rise to neurospheres with a lower frequency and produced smaller neurospheres than control cells in vitro, indicating reduction of self-renewal and expansion of neural progenitors by IE2. At 2 days after in utero electroporation into the ventricle of the developing brain, a dramatically lower percentage of IE2-expressing cells was detected in the ventricular zone (VZ) and cortical plate (CP) compared to control cells, suggesting that IE2 concurrently dysregulates neural stem cell maintenance in the VZ and neuronal migration to the CP. In addition, most IE2+ cells in the lower intermediate zone either showed multipolar morphology with short neurites or possessed nonradially oriented processes, whereas control cells had long, radially oriented monopolar or bipolar neurites. IE2+ callosal axons also failed to cross the midline to form the corpus callosum. Furthermore, we provide molecular evidence that the cell cycle arrest and DNA binding activities of IE2 appear to be responsible for the increased neural stem cell exit from the VZ and cortical migrational defects, respectively. Collectively, our results demonstrate that IE2 disrupts the orderly process of brain development in a stepwise manner to further our understanding of neurodevelopmental HCMV pathogenesis. IMPORTANCE HCMV brain pathogenesis has been studied in limited experimental settings, such as in vitro HCMV infection of neural progenitor cells or in vivo murine CMV infection of the mouse brain. Here, we show that IE2 is a pivotal factor that contributes to HCMV-induced abnormalities in the context of the embryonic brain using an in utero gene transfer tool. Surprisingly, IE2, but not HCMV IE1 or murine CMV ie3, interferes pleiotropically with key neurodevelopmental processes, including neural stem cell regulation, proper positioning of migrating neurons, and the callosal axon projections important for communication between the hemispheres. Our data suggest that the wide spectrum of clinical outcomes, ranging from mental retardation to microcephaly, caused by congenital HCMV infection can be sufficiently explained in terms of IE2 action alone.

scholarly journals A systemic transcriptome analysis reveals the regulation of neural stem cell maintenance by an E2F1–miRNA feedback loop

2013 ◽  
Vol 41 (6) ◽  
pp. 3699-3712 ◽  
Author(s):  
Thomas Palm ◽  
Kathrin Hemmer ◽  
Julia Winter ◽  
Inga B. Fricke ◽  
Katsiaryna Tarbashevich ◽  
...  
Keyword(s):  
Stem Cell ◽  
Neural Stem Cell ◽  
Transcriptome Analysis ◽  
Feedback Loop ◽  
Stem Cell Maintenance ◽  
Cell Maintenance

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.

Multifunctional silica-coated iron oxide nanoparticles: a facile four-in-one system for in situ study of neural stem cell harvesting

2014 ◽  
Vol 175 ◽  
pp. 13-26 ◽  
Author(s):  
Yung-Kang Peng ◽  
Cathy N. P. Lui ◽  
Tsen-Hsuan Lin ◽  
Chen Chang ◽  
Pi-Tai Chou ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Iron Oxide ◽  
Magnetic Resonance ◽  
Neural Stem Cells ◽  
Neural Stem Cell ◽  
Cell Therapies ◽  
Bimodal Imaging

Neural stem cells (NSCs), which generate the main phenotypes of the nervous system, are multipotent cells and are able to differentiate into multiple cell types via external stimuli from the environment. The extraction, modification and re-application of NSCs have thus attracted much attention and raised hopes for novel neural stem cell therapies and regenerative medicine. However, few studies have successfully identified the distribution of NSCs in a live brain and monitored the corresponding extraction processes both in vitro and in vivo. To address those difficulties, in this study multi-functional uniform nanoparticles comprising an iron oxide core and a functionalized silica shell (Fe3O4@SiO2(FITC)-CD133, FITC: a green emissive dye, CD133: anti-CD133 antibody) have been strategically designed and synthesized for use as probe nanocomposites that provide four-in-one functionality, i.e., magnetic agitation, dual imaging (both magnetic resonance and optical) and specific targeting. It is shown that these newly synthesized Fe3O4@SiO2(FITC)-CD133 particles have clearly demonstrated their versatility in various applications. (1) The magnetic core enables magnetic cell collection and T2 magnetic resonance imaging. (2) The fluorescent FITC embedded in the silica framework enables optical imaging. (3) CD133 anchored on the outermost surface is demonstrated to be capable of targeting neural stem cells for cell collection and bimodal imaging.

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