scholarly journals Intestinal progenitor P-bodies maintain stem cell identity by suppressing pro-differentiation factors

2020 ◽  
Author(s):  
Kasun Buddika ◽  
Yi-Ting Huang ◽  
Alex Butrum-Griffith ◽  
Sam A. Norrell ◽  
Alex M. O’Connor ◽  
...  
Keyword(s):  
Stem Cell ◽  
Cell Fate ◽  
Transcriptional Control ◽  
Adult Stem Cell ◽  
Loss Of Function ◽  
P Bodies ◽  
Stem Cell Maintenance ◽  
Differentiated Cells ◽  
Stem Cell Populations

AbstractPost-transcriptional gene regulatory mechanisms allow cells to quickly respond to environmental variation without relying on nascent transcription. However, the role of these mechanisms in cell fate transitions in adult stem cell populations remain poorly understood. We address this question here by investigating the role of Processing bodies (P-bodies), a key site of post-transcriptional control, in adult Drosophila intestinal stem cells. We report that this cell type, but not surrounding differentiated cells, harbor P-bodies that contain Drosophila orthologs of mammalian P-body components DDX6, EDC3, EDC4 and LSM14A/B and are ultrastructurally organized in a “core-shell” structure. A targeted RNAi screen identified 100+ genes that affect normal P-body morphology including patr-1, which is required for mature P-body assembly. Using both verified patr-1 RNAi strains and newly generated patr-1 loss-of-function alleles, we show that P-body assembly defects correlate with loss of intestinal progenitors. RNA-seq analysis found that patr-1 mutant progenitors inappropriately express enterocyte (EC)-specific genes, leading to precocious EC differentiation. We further demonstrate that this process is independent of well-known transcriptional repressor escargot, indicating P-body-dependent post-transcriptional regulation of pro-differentiation genes. Taken together, this work delineates the importance of post-transcriptional mechanisms in adult stem cell maintenance.

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
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Fate ◽  
Embryonic Stem ◽  
Isocitrate Dehydrogenase 1 ◽  
Advisory Committees ◽  
Metabolic Intermediates ◽  
Stem Cell Maintenance ◽  
Differentiated Cells ◽  
Methylation Of Dna

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.

scholarly journals The RNA binding protein Swm is critical for Drosophila melanogaster intestinal progenitor cell maintenance

2022 ◽  
Author(s):  
Ishara S Ariyapala ◽  
Kasun Buddika ◽  
Heather A Hundley ◽  
Brian Calvi ◽  
Nicholas Sokol
Keyword(s):  
Stem Cell ◽  
Progenitor Cells ◽  
Progenitor Cell ◽  
Transcriptional Control ◽  
Rna Binding ◽  
Rna Binding Protein ◽  
Adult Stem Cell ◽  
Stem Cell Maintenance ◽  
And Function ◽  
Cell Maintenance

The regulation of stem cell survival, self-renewal, and differentiation is critical for the maintenance of tissue homeostasis. Although the involvement of signaling pathways and transcriptional control mechanisms in stem cell regulation have been extensively investigated, the role of post-transcriptional control is still poorly understood. Here we show that the nuclear activity of the RNA-binding protein Second Mitotic Wave Missing (Swm) is critical for Drosophila intestinal stem cells (ISCs) and their daughter cells, enteroblasts (EBs), to maintain their identity and function. Loss of swm in these intestinal progenitor cells leads ISCs and EBs to lose defined cell identities, fail to proliferate, and detach from the basement membrane, resulting in severe progenitor cell loss. swm loss further causes nuclear accumulation of poly(A)+ RNA in progenitor cells. Swm associates with transcripts involved in epithelial cell maintenance and adhesion, and the loss of swm, while not generally affecting the levels of these Swm-bound mRNAs, leads to elevated expression of proteins encoded by some of them, including the fly orthologs of Filamin and Talin. Taken together, this study indicates a role for Swm in adult stem cell maintenance, and raises the possibility that nuclear post-transcriptional gene regulation plays vital roles in controlling adult stem cell maintenance and function.

scholarly journals Celsr1a is essential for tissue homeostasis and onset of aging phenotypes in the zebrafish

2019 ◽  
Author(s):  
Chunmei Li ◽  
Carrie Barton ◽  
Katrin Henke ◽  
Jake Daane ◽  
Joana Caetano-Lopes ◽  
...  
Keyword(s):  
Stem Cell ◽  
Cell Fate ◽  
Progenitor Cell ◽  
Genetic Basis ◽  
Premature Aging ◽  
Vertebrate Development ◽  
Loss Of Function ◽  
Mutagenesis Screen ◽  
Stem Cell Maintenance ◽  
Type Receptor

SUMMARYThe use of experimental genetics has been invaluable in defining the complex mechanisms by which aging and longevity are regulated. Zebrafish, while a prominent model for understanding the genetic basis of vertebrate development, have not been used systematically to address questions of how and why we age. In a mutagenesis screen focusing on late developmental phenotypes, we identified a new mutant, fruehrentner, that displays typical signs of aging already at young adult stages. We find that the phenotype is due to loss-of-function in the non-classical cadherin EGF LAG seven-pass G-type receptor 1a (celsr1a). The premature aging phenotype is not associated with increased cellular senescence or decreased telomere length but is a result of a broad failure to maintain progenitor cell populations in tissues. Through the analysis of a knockin reporter line, we find that celsr1aGFP is expressed broadly in early development but becomes restricted during maturation. We show that celsr1a is essential for maintenance of stem cell progenitors and leads to shifts in cell fate determination. Although celsr1a has many signaling functions including establishment of polarity within tissues, we show that caloric restriction can ameliorate the effect of celsr1a on lifespan in part through compensatory upregulation of celsr1 paralogues. These data suggest that celsr1a function helps to mediate stem cell maintenance during maturation and homeostasis of tissues and thus regulates the onset or expressivity of aging phenotypes.

scholarly journals The Role of β-Arrestins in Regulating Stem Cell Phenotypes in Normal and Tumorigenic Cells

2020 ◽  
Vol 21 (23) ◽  
pp. 9310
Author(s):  
Georgios Kallifatidis ◽  
Kenza Mamouni ◽  
Bal L. Lokeshwar
Keyword(s):  
Stem Cell ◽  
G Protein ◽  
Cell Biology ◽  
Myeloproliferative Neoplasms ◽  
Stem Cell Maintenance ◽  
Health And Disease ◽  
Stem Cell Populations ◽  
Cell Phenotypes ◽  
Cell Maintenance

β-Arrestins (ARRBs) are ubiquitously expressed scaffold proteins that mediate inactivation of G-protein-coupled receptor signaling, and in certain circumstances, G-protein independent pathways. Intriguingly, the two known ARRBs, β-arrestin1 (ARRB1) and β-Arrestin2 (ARRB2), seem to have opposing functions in regulating signaling cascades in several models in health and disease. Recent evidence suggests that ARRBs are implicated in regulating stem cell maintenance; however, their role, although crucial, is complex, and there is no universal model for ARRB-mediated regulation of stem cell characteristics. For the first time, this review compiles information on the function of ARRBs in stem cell biology and will discuss the role of ARRBs in regulating cell signaling pathways implicated in stem cell maintenance in normal and malignant stem cell populations. Although promising targets for cancer therapy, the ubiquitous nature of ARRBs and the plethora of functions in normal cell biology brings challenges for treatment selectivity. However, recent studies show promising evidence for specifically targeting ARRBs in myeloproliferative neoplasms.

scholarly journals RUNX transcription factors at the interface of stem cells and cancer

2017 ◽  
Vol 474 (11) ◽  
pp. 1755-1768 ◽  
Author(s):  
Elitza Deltcheva ◽  
Rachael Nimmo
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Fate ◽  
Current Knowledge ◽  
Point Mutations ◽  
Causative Factor ◽  
Ovarian Tumour ◽  
Loss Of Function ◽  
Genetic Changes

The RUNX1 transcription factor is a critical regulator of normal haematopoiesis and its functional disruption by point mutations, deletions or translocations is a major causative factor leading to leukaemia. In the majority of cases, genetic changes in RUNX1 are linked to loss of function classifying it broadly as a tumour suppressor. Despite this, several recent studies have reported the need for a certain level of active RUNX1 for the maintenance and propagation of acute myeloid leukaemia and acute lymphoblastic leukaemia cells, suggesting an oncosupportive role of RUNX1. Furthermore, in solid cancers, RUNX1 is overexpressed compared with normal tissue, and RUNX factors have recently been discovered to promote growth of skin, oral, breast and ovarian tumour cells, amongst others. RUNX factors have key roles in stem cell fate regulation during homeostasis and regeneration of many tissues. Cancer cells appear to have corrupted these stem cell-associated functions of RUNX factors to promote oncogenesis. Here, we discuss current knowledge on the role of RUNX genes in stem cells and as oncosupportive factors in haematological malignancies and epithelial cancers.

scholarly journals TAp63 Prevents Premature Aging by Promoting Adult Stem Cell Maintenance

2009 ◽  
Vol 5 (1) ◽  
pp. 64-75 ◽  
Author(s):  
Xiaohua Su ◽  
Maryline Paris ◽  
Young Jin Gi ◽  
Kenneth Y. Tsai ◽  
Min Soon Cho ◽  
...  
Keyword(s):  
Stem Cell ◽  
Adult Stem Cell ◽  
Premature Aging ◽  
Stem Cell Maintenance ◽  
Cell Maintenance

scholarly journals COUP-TFII Regulates Human Endometrial Stromal Genes Involved in Inflammation

2013 ◽  
Vol 27 (12) ◽  
pp. 2041-2054 ◽  
Author(s):  
Xilong Li ◽  
Michael J. Large ◽  
Chad J. Creighton ◽  
Rainer B. Lanz ◽  
Jae-Wook Jeong ◽  
...  
Keyword(s):  
Cell Fate ◽  
Cell Biology ◽  
Embryo Implantation ◽  
Orphan Nuclear Receptor ◽  
Loss Of Function ◽  
Mouse Uterus ◽  
Endometrial Stromal Cells ◽  
Endometrial Stroma ◽  
Stroma Cell

Chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII; NR2F2) is an orphan nuclear receptor involved in cell-fate specification, organogenesis, angiogenesis, and metabolism. Ablation of COUP-TFII in the mouse uterus causes infertility due to defects in embryo attachment and impaired uterine stromal cell decidualization. Although the function of COUP-TFII in uterine decidualization has been described in mice, its role in the human uterus remains unknown. We observed that, as in mice, COUP-TFII is robustly expressed in the endometrial stroma of healthy women, and its expression is reduced in the ectopic lesions of women with endometriosis. To interrogate the role of COUP-TFII in human endometrial function, we used a small interfering RNA-mediated loss of function approach in primary human endometrial stromal cells. Attenuation of COUP-TFII expression did not completely block decidualization; rather it had a selective effect on gene expression. To better elucidate the role of COUP-TFII in endometrial stroma cell biology, the COUP-TFII transcriptome was defined by pairing microarray comparison with chromatin immunoprecipitation followed by deep sequencing. Gene ontology analysis demonstrates that COUP-TFII regulates a subset of genes in endometrial stroma cell decidualization such as those involved in cell adhesion, angiogenesis, and inflammation. Importantly this analysis shows that COUP-TFII plays a role in controlling the expression of inflammatory cytokines. The determination that COUP-TFII plays a role in inflammation may add insight into the role of COUP-TFII in embryo implantation and in endometrial diseases such as endometriosis.

scholarly journals The dynamic role of bone morphogenetic proteins in neural stem cell fate and maturation

2012 ◽  
Vol 72 (7) ◽  
pp. 1068-1084 ◽  
Author(s):  
Allison M. Bond ◽  
Oneil G. Bhalala ◽  
John A. Kessler
Keyword(s):  
Stem Cell ◽  
Cell Fate ◽  
Neural Stem Cell ◽  
Bone Morphogenetic Proteins ◽  
Stem Cell Fate

PIN-FORMED 1 regulates cell fate at the periphery of the shoot apical meristem

Development ◽  
2000 ◽  
Vol 127 (23) ◽  
pp. 5157-5165 ◽  
Author(s):  
T. Vernoux ◽  
J. Kronenberger ◽  
O. Grandjean ◽  
P. Laufs ◽  
J. Traas
Keyword(s):  
Cell Fate ◽  
Apical Meristem ◽  
Transmembrane Protein ◽  
Loss Of Function ◽  
Hybrid Identity ◽  
Hormone Transport ◽  
Early Markers ◽  
Ideal Tool ◽  
And Function

The process of organ positioning has been addressed, using the pin-formed 1 (pin1) mutant as a tool. PIN1 is a transmembrane protein involved in auxin transport in Arabidopsis. Loss of function severely affects organ initiation, and pin1 mutants are characterised by an inflorescence meristem that does not initiate any flowers, resulting in the formation of a naked inflorescence stem. This phenotype, combined with the proposed role of PIN1 in hormone transport, makes the mutant an ideal tool to study organ formation and phyllotaxis, and here we present a detailed analysis of the molecular modifications at the shoot apex caused by the mutation. We show that meristem structure and function are not severely affected in the mutant. Major alterations, however, are observed at the periphery of the pin1 meristem, where organ initiation should occur. Although two very early markers of organ initiation, LEAFY and AINTEGUMENTA, are expressed at the periphery of the mutant meristem, the cells are not recruited into distinct primordia. Instead a ring-like domain expressing those primordium specific genes is observed around the meristem. This ring-like domain also expresses a boundary marker, CUP-SHAPED COTYLEDON 2, involved in organ separation, showing that the zone at the meristem periphery has a hybrid identity. This implies that PIN1 is not only involved in organ outgrowth, but that it is also necessary for organ separation and positioning. A model is presented in which PIN1 and the local distribution of auxin control phyllotaxis.

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