scholarly journals TUNAR lncRNA Encodes a Microprotein that Regulates Neural Differentiation and Neurite Formation by Modulating Calcium Dynamics

2021 ◽  
Vol 9 ◽  
Author(s):  
Elena Senís ◽  
Miriam Esgleas ◽  
Sonia Najas ◽  
Verónica Jiménez-Sábado ◽  
Camilla Bertani ◽  
...  
Keyword(s):  
Neural Differentiation ◽  
Transmembrane Protein ◽  
Embryonic Stem ◽  
Model Systems ◽  
General Point ◽  
Differentiation Potential ◽  
Neural Lineage ◽  
Small Proteins ◽  
Neurite Formation

Long noncoding RNAs (lncRNAs) are regulatory molecules which have been traditionally considered as “non-coding”. Strikingly, recent evidence has demonstrated that many non-coding regions, including lncRNAs, do in fact contain small-open reading frames that code for small proteins that have been called microproteins. Only a few of them have been characterized so far, but they display key functions in a wide variety of cellular processes. Here, we show that TUNAR lncRNA encodes an evolutionarily conserved microprotein expressed in the nervous system that we have named pTUNAR. pTUNAR deficiency in mouse embryonic stem cells improves their differentiation potential towards neural lineage both in vitro and in vivo. Conversely, pTUNAR overexpression impairs neuronal differentiation by reduced neurite formation in different model systems. At the subcellular level, pTUNAR is a transmembrane protein that localizes in the endoplasmic reticulum and interacts with the calcium transporter SERCA2. pTUNAR overexpression reduces cytoplasmatic calcium, consistent with a possible role of pTUNAR as an activator of SERCA2. Altogether, our results suggest that our newly discovered microprotein has an important role in neural differentiation and neurite formation through the regulation of intracellular calcium. From a more general point of view, our results provide a proof of concept of the role of lncRNAs-encoded microproteins in neural differentiation.

scholarly journals Promotion of Neurite and Filopodium Formation by CD47: Roles of Integrins, Rac, and Cdc42

2004 ◽  
Vol 15 (8) ◽  
pp. 3950-3963 ◽  
Author(s):  
Motoaki Miyashita ◽  
Hiroshi Ohnishi ◽  
Hideki Okazawa ◽  
Hiroyasu Tomonaga ◽  
Akiko Hayashi ◽  
...  
Keyword(s):  
Transmembrane Protein ◽  
Neuroblastoma Cells ◽  
Axon Extension ◽  
Entire Structure ◽  
Signaling Mechanisms ◽  
Extracellular Region ◽  
Fc Fusion Protein ◽  
Neurite Formation ◽  
Filopodium Formation

Axon extension during development is guided by many factors, but the signaling mechanisms responsible for its regulation remain largely unknown. We have now investigated the role of the transmembrane protein CD47 in this process in N1E-115 neuroblastoma cells. Forced expression of CD47 induced the formation of neurites and filopodia. Furthermore, an Fc fusion protein containing the extracellular region of the CD47 ligand SHPS-1 induced filopodium formation, and this effect was enhanced by CD47 overexpression. SHPS-1–Fc also promoted neurite and filopodium formation triggered by serum deprivation. Inhibition of Rac or Cdc42 preferentially blocked CD47-induced formation of neurites and filopodia, respectively. Overexpression of CD47 resulted in the activation of both Rac and Cdc42. The extracellular region of CD47 was sufficient for the induction of neurite formation by forced expression, but the entire structure of CD47 was required for enhancement of filopodium formation by SHPS-1–Fc. Neurite formation induced by CD47 was also inhibited by a mAb to the integrin β3 subunit. These results indicate that the interaction of SHPS-1 with CD47 promotes neurite and filopodium formation through the activation of Rac and Cdc42, and that integrins containing the β3 subunit participate in the effect of CD47 on neurite formation.

scholarly journals Dichotomous role of Shp2 for naïve and primed pluripotency maintenance in embryonic stem cells

2021 ◽  
Author(s):  
Seong Min Kim ◽  
Eun-Ji Kwon ◽  
Yun-Jeong Kim ◽  
Young-Hyun Go ◽  
Ji-Young Oh ◽  
...  
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Embryonic Stem ◽  
Erk Signaling ◽  
Differentiation Potential ◽  
Stat3 Signaling ◽  
Stat3 Phosphorylation ◽  
Pluripotency Maintenance

Abstract The requirement of the Mek1 inhibitor (iMek1) during naïve pluripotency maintenance results from the activation of the Mek1-Erk1/2 (Mek/Erk) signaling pathway upon leukemia inhibitory factor (LIF) stimulation. Through a meta-analysis of previous genome-wide screening for negative regulators of naïve pluripotency, Ptpn11 (encoding the Shp2 protein, which serves both as a tyrosine phosphatase and putative adapter), was predicted as one of the key factors for the negative modulation of naïve pluripotency through LIF-dependent Jak/Stat3 signaling. Using an isogenic pair of naïve and primed mouse embryonic stem cells (mESCs), we demonstrated the differential role of Shp2 in naïve and primed pluripotency. Loss of Shp2 increased naive pluripotency by promoting Jak/Stat3 signaling and disturbed in vivo differentiation potential. In sharp contrast, Shp2 depletion significantly impeded the self-renewal of ESCs under primed culture conditions, which was concurrent with a reduction in Mek/Erk signaling. Similarly, upon treatment with an allosteric Shp2 inhibitor (iShp2), the cells sustained Stat3 phosphorylation and decoupled Mek/Erk signaling, thus replacing the use of iMek1 not only for maintenance but also for the establishment of naïve ESCs through reprogramming. Taken together, our findings highlight the differential roles of Shp2 in naïve and primed pluripotency and propose the usage of iShp2 instead of iMek1 for the efficient maintenance and establishment of naïve pluripotency.

scholarly journals EOMES is responsible for WNT memory and can substitute for WNT in mesendoderm specification

2021 ◽  
Author(s):  
Anna Yoney ◽  
Lu Bai ◽  
Ali H. Brivanlou ◽  
Eric D Siggia
Keyword(s):  
Target Genes ◽  
Embryonic Stem ◽  
Model Systems ◽  
Mechanistic Basis ◽  
Vitro Model ◽  
Transcriptional Output ◽  
Accessible Chromatin ◽  
Pluripotency Maintenance

Embryogenesis is guided by a limited set of signaling pathways that are reused at different times and places throughout development. How a context dependent signaling response is generated has been a central question of developmental biology, which can now be addressed with in vitro model systems. Our previous work in human embryonic stem cells (hESCs) established that pre-exposure of cells to WNT/β-catenin signaling is sufficient to switch the output of ACTIVIN/SMAD2 signaling from pluripotency maintenance to mesendoderm (ME) differentiation. A body of previous literature has established the role of both pathways in ME differentiation. However, our work demonstrated that the two signals do not need to be present simultaneously and that hESCs have a means to record WNT signals. Here we demonstrate that hESCs have accessible chromatin at SMAD2 binding sites near pluripotency and ME-associated target genes and that WNT priming does not alter SMAD2 binding. Rather our results indicate that stable transcriptional output at ME genes results from WNT-dependent production of an additional SMAD2 co-factor, EOMES. We show that expression of EOMES can replace WNT signaling in ME differentiation, providing a mechanistic basis for WNT-priming and memory in early development.

Abstract P482: Elucidating And Characterizing The Molecular Mechanistic Role Of Phospholamban L39 Stop In The Pathophysiology Of Cardiomyopathy Using Patient-derived Human Induced Pluripotent Stem Cells And Humanized Knock-in Mouse Model Systems

2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
Anichavezhi Devendran ◽  
Rasheed Bailey ◽  
Sumanta Kar ◽  
Francesca Stillitano ◽  
Irene Turnbull ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mouse Model ◽  
Mononuclear Cells ◽  
Embryonic Stem ◽  
Model Systems ◽  
Patient Specific ◽  
Induced Pluripotent

Background: Heart failure (HF) is a complex clinical condition associated with substantial morbidity and mortality worldwide. The contractile dysfunction and arrhythmogenesis related to HF has been linked to the remodelling of calcium (Ca ++ ) handling. Phospholamban (PLN) has emerged as a key regulator of intracellular Ca ++ concentration. Of the PLN mutations, L39X is intriguing as it has not been fully characterized. This mutation is believed to be functionally equivalent to PLN null (KO) but contrary to PLN KO mice, L39X carriers develop a lethal cardiomyopathy (CMP). Our study aims at using induced pluripotent stem cell (iPSC)-derived cardiomyocytes (CMs) from homozygous L39X carriers to elucidate the role of L39X in human pathophysiology. Our plan also involves the characterization of humanized L39X knock-in mice (KM), which we hypothesize will develop a CMP from mis-localization of PLN and disruption of Ca ++ signalling. Methodology and Results: Mononuclear cells from Hom L39X carriers were obtained to generate 11 integration-free patient-specific iPSC clones. The iPSC-CMs were derived using established protocols. Compared to the WT iPSC-CMs, the Hom L39X derived-CMs PLN had an abnormal cytoplasmic distribution and formed intracellular aggregates, with the loss of perinuclear localization. There was also a 70% and 50% reduction of mRNA and protein expression of PLN respectively in L39X compared to WT iPSC-CMs. These findings indicated that L39X PLN is both under-expressed and mis-localized within the cell. To validate this observation in-vivo, we genetically modified FVB mice to harbour the human L39X. Following electroporation, positively transfected mouse embryonic stem cells were injected into host blastocysts to make humanized KM that were subsequently used to generate either a protamine-Cre (endogenous PLN driven expression) or a cardiac TNT mouse (i.e., CMP specific). Conclusion: Our data confirm an abnormal intracellular distribution of PLN, with the loss of perinuclear accumulation and mis-localization, suggestive of ineffective targeting to or retention of L39X. The mouse model will be critically important to validate the in-vitro observations and provides an ideal platform for future studies centred on the development of novel therapeutic strategies including virally delivered CRISPR/Cas9 for in-vivo gene editing and testing of biochemical signalling pathways.

Alteration of gene expression profile in mouse embryonic stem cells and neural differentiation deficits by ethephon

2020 ◽  
Vol 39 (11) ◽  
pp. 1518-1527
Author(s):  
S Mohammadi Nejad ◽  
M Hodjat ◽  
SA Mousavi ◽  
M Baeeri ◽  
MA Rezvanfar ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Cycle ◽  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Gene Expression Profile ◽  
Expression Profile ◽  
Neural Differentiation ◽  
Embryonic Stem ◽  
Mouse Embryonic Stem Cells ◽  
Differentiation Potential

Ethephon, a member of the organophosphorus compounds, is one of the most widely used plant growth regulators for artificial ripening. Although million pounds of this chemical is being used annually, the knowledge regarding its molecular toxicity is yet not sufficient. The purpose of this study was to evaluate the potential developmental toxicity of ethephon using embryonic stem cell model. The mouse embryonic stem cells (mESCs) were exposed to various concentrations of ethephon and the viability, cell cycle alteration and changes in the gene expression profile were evaluated using high-throughput RNA sequencing. Further, the effect of ethephon on neural differentiation potential was examined. The results showed that ethephon at noncytotoxic doses induced cell cycle arrest in mESCs. Gene ontology enrichment analysis showed that terms related to cell fate and organismal development, including neuron fate commitment, embryo development and cardiac cell differentiation, were markedly enriched in ethephon-treated cells. Neural induction of mESCs in the presence of ethephon was inhibited and the expression of neural genes was decreased in differentiated cells. Results obtained from this work clearly demonstrate that ethephon affects the gene expression profile of undifferentiated mESCs and prevents neural differentiation. Therefore, more caution against the frequent application of ethephon is advised.

scholarly journals The role of Ca2+ signaling on the self-renewal and neural differentiation of embryonic stem cells (ESCs)

Cell Calcium ◽  
2016 ◽  
Vol 59 (2-3) ◽  
pp. 67-74 ◽  
Author(s):  
Baixia Hao ◽  
Sarah E. Webb ◽  
Andrew L. Miller ◽  
Jianbo Yue
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Neural Differentiation ◽  
Embryonic Stem ◽  
The Self ◽  
Self Renewal

scholarly journals Absence of Rybp Compromises Neural Differentiation of Embryonic Stem Cells

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Gergo Kovacs ◽  
Viktoria Szabo ◽  
Melinda K. Pirity
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Neural Differentiation ◽  
Embryonic Stem ◽  
Wild Type ◽  
Altered Gene Expression ◽  
Molecular Events ◽  
Altered Gene ◽  
Polycomb Repressive Complex 1

Rybp (Ring1 and Yy1 Binding Protein) is a transcriptional regulator and member of the noncanonical polycomb repressive complex 1 with essential role in early embryonic development. We have previously described that alteration of Rybp dosage in mouse models induced striking neural tube defects (NTDs), exencephaly, and disorganized neurocortex. In this study we further investigated the role of Rybp in neural differentiation by utilising wild type (rybp+/+) andrybp nullmutant (rybp-/-) embryonic stem cells (ESCs) and tried to uncover underlying molecular events that are responsible for the observed phenotypic changes. We found thatrybp nullmutant ESCs formed less matured neurons, astrocytes, and oligodendrocytes from existing progenitors than wild type cells. Furthermore, lack ofrybpcoincided with altered gene expression of key neural markers including Pax6 and Plagl1 pinpointing a possible transcriptional circuit among these genes.

scholarly journals Neural Differentiation Is Inhibited through HIF1α/β-Catenin Signaling in Embryoid Bodies

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Josef Večeřa ◽  
Jana Kudová ◽  
Jan Kučera ◽  
Lukáš Kubala ◽  
Jiří Pacherník
Keyword(s):  
Stem Cells ◽  
Cell Fate ◽  
Neural Differentiation ◽  
Embryonic Stem ◽  
Direct Interaction ◽  
Embryoid Bodies ◽  
Nuclear Fraction ◽  
Wild Type ◽  
Spontaneous Differentiation

Extensive research in the field of stem cells and developmental biology has revealed evidence of the role of hypoxia as an important factor regulating self-renewal and differentiation. However, comprehensive information about the exact hypoxia-mediated regulatory mechanism of stem cell fate during early embryonic development is still missing. Using a model of embryoid bodies (EBs) derived from murine embryonic stem cells (ESC), we here tried to encrypt the role of hypoxia-inducible factor 1α (HIF1α) in neural fate during spontaneous differentiation. EBs derived from ESC with the ablated gene for HIF1α had abnormally increased neuronal characteristics during differentiation. An increased neural phenotype in Hif1α−/− EBs was accompanied by the disruption of β-catenin signaling together with the increased cytoplasmic degradation of β-catenin. The knock-in of Hif1α, as well as β-catenin ectopic overexpression in Hif1α−/− EBs, induced a reduction in neural markers to the levels observed in wild-type EBs. Interestingly, direct interaction between HIF1α and β-catenin was demonstrated by immunoprecipitation analysis of the nuclear fraction of wild-type EBs. Together, these results emphasize the regulatory role of HIF1α in β-catenin stabilization during spontaneous differentiation, which seems to be a crucial mechanism for the natural inhibition of premature neural differentiation.

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