scholarly journals Neuromesodermal progenitors separate the axial stem zones while producing few single- and dual-fated descendants

2019 ◽  
Author(s):  
Timothy R. Wood ◽  
Anders Kyrsting ◽  
Johannes Stegmaier ◽  
Iwo Kucinski ◽  
Clemens F. Kaminski ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cell Fate ◽  
In Vivo Imaging ◽  
Small Region ◽  
Cell Populations ◽  
Molecular Identity ◽  
Multipotent Cells ◽  
Classical Boundary ◽  
Stem Cell Populations

AbstractMost embryos and regenerating tissues grow by the action of stem zones. Two epithelial stem zones drive axial elongation in amniotes: the mature organizer generates mesoderm, the neuralised ectoderm around it extends the neuraxis. Bipotential progenitors were also shown to exist. How are these stem cell populations organised and what controls the cell fate of bipotential progenitors? We use direct, in vivo imaging of these stem cells in the chick. We find that progenitors of single and dual fates are mingled in a small region between the specialised stem zones. Divergent tissue movements surround this region. When transplanted downstream of these flows, cells from the region of mixed fates adopt the molecular identity and behaviour of the target stem zone, irrespective of their normal fate. Thus, multipotent cells serve to separate the specialized stem zones, instead of a classical boundary. We propose their fate is determined extrinsically by morphogenetic shearing.

Stem Cells in Paediatric Leukaemia Are Resistant to Parthenolide.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1429-1429
Author(s):  
Charlotte Victoria Cox ◽  
Paraskevi Diamanti ◽  
Allison Blair
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Functional Capacity ◽  
Cell Populations ◽  
Minimal Effect ◽  
Childhood All ◽  
Stem Cell Populations

Abstract Abstract 1429 Poster Board I-452 The concept of cancer stem cells as developmentally early cells that are capable of continued growth and expansion in haematopoietic malignancies and solid tumours has been substantiated in recent years. Consequently these cells may be responsible for disease maintenance and relapse. Acute lymphoblastic leukaemia (ALL) is the most common paediatric cancer with survival rates around 80-85%. However, a significant proportion of patients relapse, often with disease that is highly refractory to further therapeutic intervention. Leukaemia stem cells have been described in childhood ALL that can proliferate to initiate and sustain the disease in vivo. In addition these leukaemia stem cells have also been shown to be refractory to commonly used clinical agents. Therefore it is important to investigate ALL stem cells to understand their biological properties and to identify the most appropriate agents that are capable of eradicating these cells. The sesquiterpene lactone Parthenolide (PTL) has been shown to induce apoptosis in malignant cells by inducing oxidative stress and inhibiting NF-κB activity. Importantly PTL has been shown to be effective against stem cell populations in acute myeloid leukaemia and in chronic lymphocytic leukaemia with minimal effect on normal haemopoietic cells. In this study we have attempted to assess the effects of PTL on stem cell populations in paediatric ALL. Primary cells from 20 childhood ALL cases from mixed prognostic subgroups were used in this investigation. Cells from B-ALL cases were sorted on the basis of expression of CD34/CD19, while CD34/CD7 antigens were used to sort cells from T-ALL cases. Sorted and unsorted populations were co-cultured with and without PTL at 7.5μM and 10μM for 18-24 hours. Subsequently cell viability and apoptosis were determined by flow cytometry using Annexin V and PI staining. Antibodies against phosphorylated IKKα and IKKβ were used to assess NF-κB activity in treated and untreated cells. The functional ability of the treated cells was assessed in some cases using long-term in vitro and in vivo assays. Both concentrations of PTL resulted in a significant reduction in viability in unsorted ALL cells (28±4% and 23±5% respectively). Similar results were observed with CD34+/CD19+, CD34+/CD7+ and CD34- subfractions, with viability reduced to 14-39%. In contrast the phenotypically primitive CD34+/CD19- (85±11% viable) and CD34+/CD7- (83±5% viable) populations were significantly more resistant to 10μM PTL than unsorted cells and other sorted populations (P≤0.002). FISH analyses were performed at the end of the time-course and confirmed that leukaemia cells were surviving PTL treatment. It was not possible to detect phosphorylated IKKα/β in the CD34+/CD19- and CD34+/CD7- populations, in cases examined to date, suggesting NF-kB may not be active in these subpopulations. Of note PTL treatment seemed to have minimal effect on the long-term proliferative ability of ALL cells. There were no significant differences in the absolute cell numbers generated in cultures of PTL treated CD34+/CD19- or CD34+/CD7- cells compared to untreated cells at all time points assayed up to the end of culture at week 6 (P≥0.23). Interestingly, similar results were observed with the unsorted cells and all other sorted populations. From week 3 of culture there was no difference in the absolute cell counts when growth from treated and untreated cells was compared (P>0.47), albeit they proliferated to a much lesser extent than the phenotypically primitive populations. In addition PTL treated cells were capable of engrafting NOD/SCID mice. The levels of leukaemia engraftment obtained using PTL treated unsorted (0.2-5% CD45+), CD34+/CD19- (2-10% CD45+) and CD34+/CD7- (1.5-9% CD45+) populations were similar to their respective untreated controls. These data demonstrate that while PTL showed promising effects on the bulk leukaemia cells, the effects on CD34+/CD19- B-ALL cells and CD34+/CD7- T-ALL cells were insignificant. This may be due in part to lack of NF-kB activity in leukaemia stem cells. However, the functional capacity of every ALL population evaluated in vitro was not significantly impaired by the short course of PTL treatment. These findings further highlight the importance of evaluating new therapeutic agents on leukaemia stem cell populations in addition to the bulk leukaemia and the significance of investigating the functional capacity of drug treated cells. Disclosures No relevant conflicts of interest to declare.

scholarly journals Quiescent, Slow-Cycling Stem Cell Populations in Cancer: A Review of the Evidence and Discussion of Significance

2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Nathan Moore ◽  
Stephen Lyle
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Stem Cell ◽  
Cancer Stem Cells ◽  
Adult Stem Cells ◽  
Cell Populations ◽  
Proliferative Potential ◽  
Cell Cycle Regulators ◽  
Slow Cycling ◽  
Stem Cell Populations

Long-lived cancer stem cells (CSCs) with indefinite proliferative potential have been identified in multiple epithelial cancer types. These cells are likely derived from transformed adult stem cells and are thought to share many characteristics with their parental population, including a quiescent slow-cycling phenotype. Various label-retaining techniques have been used to identify normal slow cycling adult stem cell populations and offer a unique methodology to functionally identify and isolate cancer stem cells. The quiescent nature of CSCs represents an inherent mechanism that at least partially explains chemotherapy resistance and recurrence in posttherapy cancer patients. Isolating and understanding the cell cycle regulatory mechanisms of quiescent cancer cells will be a key component to creation of future therapies that better target CSCs and totally eradicate tumors. Here we review the evidence for quiescent CSC populations and explore potential cell cycle regulators that may serve as future targets for elimination of these cells.

scholarly journals Cellular and molecular characterization of the role of the flk-2/flt-3 receptor tyrosine kinase in hematopoietic stem cells

Blood ◽  
1994 ◽  
Vol 84 (8) ◽  
pp. 2422-2430 ◽  
Author(s):  
FC Zeigler ◽  
BD Bennett ◽  
CT Jordan ◽  
SD Spencer ◽  
S Baumhueter ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Tyrosine Kinase ◽  
Hematopoietic Stem Cell ◽  
Receptor Tyrosine Kinase ◽  
Lymphoid Cells ◽  
Stem Cell Population ◽  
Cell Populations ◽  
Hematopoietic Stem ◽  
Stem Cell Populations

The flk-2/flt-3 receptor tyrosine kinase was cloned from a hematopoietic stem cell population and is considered to play a potential role in the developmental fate of the stem cell. Using antibodies derived against the extracellular domain of the receptor, we show that stem cells from both murine fetal liver and bone marrow can express flk-2/flt-3. However, in both these tissues, there are stem cell populations that do not express the receptor. Cell cycle analysis shows that stem cells that do not express the receptor have a greater percentage of the population in G0 when compared with the flk-2/flt-3- positive population. Development of agonist antibodies to the receptor shows a proliferative role for the receptor in stem cell populations. Stimulation with an agonist antibody gives rise to an expansion of both myeloid and lymphoid cells and this effect is enhanced by the addition of kit ligand. These studies serve to further illustrate the importance of the flk-2/flt-3 receptor in the regulation of the hematopoietic stem cell.

In Vivo Imaging of Bone Marrow Stem Cells

2014 ◽  
pp. 143-162 ◽  
Author(s):  
Luke J. Mortensen ◽  
Walid Zaher ◽  
Cristina Lo Celso ◽  
Charles P. Lin
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
In Vivo Imaging ◽  
Bone Marrow Stem Cells

Leukemic stem cells hiding in plain sight

2019 ◽  
Vol 4 (38) ◽  
pp. eaay7253
Author(s):  
Gabriel K. Griffin
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Immune Surveillance ◽  
Cell Populations ◽  
Leukemic Stem Cell ◽  
Leukemic Stem Cells ◽  
Stem Cell Populations

Activation of NK-mediated immune surveillance clears leukemic stem cell populations.

scholarly journals The nutritional environment determines which and how intestinal stem cells contribute to homeostasis and tumorigenesis

2019 ◽  
Vol 40 (8) ◽  
pp. 937-946 ◽  
Author(s):  
Wenge Li ◽  
Samuel E Zimmerman ◽  
Karina Peregrina ◽  
Michele Houston ◽  
Joshua Mayoral ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Tumor Development ◽  
Intestinal Cell ◽  
Cell Populations ◽  
Dna Mismatch ◽  
Nutrient Environment ◽  
Mucosal Homeostasis ◽  
Human Mucosa ◽  
Stem Cell Populations

Abstract Sporadic colon cancer accounts for approximately 80% of colorectal cancer (CRC) with high incidence in Western societies strongly linked to long-term dietary patterns. A unique mouse model for sporadic CRC results from feeding a purified rodent Western-style diet (NWD1) recapitulating intake for the mouse of common nutrient risk factors each at its level consumed in higher risk Western populations. This causes sporadic large and small intestinal tumors in wild-type mice at an incidence and frequency similar to that in humans. NWD1 perturbs intestinal cell maturation and Wnt signaling throughout villi and colonic crypts and decreases mouse Lgr5hi intestinal stem cell contribution to homeostasis and tumor development. Here we establish that NWD1 transcriptionally reprograms Lgr5hi cells, and that nutrients are interactive in reprogramming. Furthermore, the DNA mismatch repair pathway is elevated in Lgr5hi cells by lower vitamin D3 and/or calcium in NWD1, paralleled by reduced accumulation of relevant somatic mutations detected by single-cell exome sequencing. In compensation, NWD1 also reprograms Bmi1+ cells to function and persist as stem-like cells in mucosal homeostasis and tumor development. The data establish the key role of the nutrient environment in defining the contribution of two different stem cell populations to both mucosal homeostasis and tumorigenesis. This raises important questions regarding impact of variable human diets on which and how stem cell populations function in the human mucosa and give rise to tumors. Moreover, major differences reported in turnover of human and mouse crypt base stem cells may be linked to their very different nutrient exposures.

scholarly journals Targeting Subsets of Mammalian Neurons

2020 ◽  
Vol 15 ◽  
pp. 263310552090853
Author(s):  
Boris V. Zemelman
Keyword(s):  
In Vivo Imaging ◽  
Inhibitory Neuron ◽  
Human Perception ◽  
Cell Populations ◽  
Inhibitory Interneurons ◽  
Transcriptome Data ◽  
Functional Studies ◽  
Cell Transcriptome ◽  
Single Cell Transcriptome

Functional dissection of mammalian neuronal circuits depends on accurate targeting of constituent cell classes. Transgenic mice offer precise and predictable access to genetically defined cell populations, but there is the pressing need to target neuronal assemblies in species less amenable to genomic manipulations, such as the primate, which is an important animal model for human perception, cognition, and action. We have developed several virus-based methods for accessing all forebrain inhibitory interneurons as well as the major excitatory and inhibitory neuron subclasses. These methods rely on the wealth of emerging single-cell transcriptome data and harness gene expression variations to refine neuron targeting. Our approach enables nuanced functional studies, including in vivo imaging and manipulation, of the diverse cell populations of the mammalian neocortex, and it represents a timely blueprint for transgenics-independent interrogation of functionally significant cell classes.

scholarly journals Alternative polyadenylation of Pax3 controls muscle stem cell fate and muscle function

Science ◽  
2019 ◽  
Vol 366 (6466) ◽  
pp. 734-738 ◽  
Author(s):  
Antoine de Morree ◽  
Julian D. D. Klein ◽  
Qiang Gan ◽  
Jean Farup ◽  
Andoni Urtasun ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Fate ◽  
Messenger Rna ◽  
Adult Stem Cells ◽  
Alternative Polyadenylation ◽  
Quiescent State ◽  
Stem Cell Fate ◽  
Activation Rate

Adult stem cells are essential for tissue homeostasis. In skeletal muscle, muscle stem cells (MuSCs) reside in a quiescent state, but little is known about the mechanisms that control homeostatic turnover. Here we show that, in mice, the variation in MuSC activation rate among different muscles (for example, limb versus diaphragm muscles) is determined by the levels of the transcription factor Pax3. We further show that Pax3 levels are controlled by alternative polyadenylation of its transcript, which is regulated by the small nucleolar RNA U1. Isoforms of the Pax3 messenger RNA that differ in their 3′ untranslated regions are differentially susceptible to regulation by microRNA miR206, which results in varying levels of the Pax3 protein in vivo. These findings highlight a previously unrecognized mechanism of the homeostatic regulation of stem cell fate by multiple RNA species.

scholarly journals Effect of the 3D Artificial Nichoid on the Morphology and Mechanobiological Response of Mesenchymal Stem Cells Cultured In Vitro

Cells ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1873 ◽  
Author(s):  
Andrea Remuzzi ◽  
Barbara Bonandrini ◽  
Matteo Tironi ◽  
Lorena Longaretti ◽  
Marina Figliuzzi ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Stem Cell ◽  
Cell Fate ◽  
Cultured Cells ◽  
Three Dimensions ◽  
Nuclear Pore ◽  
Cells Cultured

Stem cell fate and behavior are affected by the bidirectional communication of cells and their local microenvironment (the stem cell niche), which includes biochemical cues, as well as physical and mechanical factors. Stem cells are normally cultured in conventional two-dimensional monolayer, with a mechanical environment very different from the physiological one. Here, we compare culture of rat mesenchymal stem cells on flat culture supports and in the “Nichoid”, an innovative three-dimensional substrate micro-engineered to recapitulate the architecture of the physiological niche in vitro. Two versions of the culture substrates Nichoid (single-layered or “2D Nichoid” and multi-layered or “3D Nichoid”) were fabricated via two-photon laser polymerization in a biocompatible hybrid organic-inorganic photoresist (SZ2080). Mesenchymal stem cells, isolated from rat bone marrow, were seeded on flat substrates and on 2D and 3D Nichoid substrates and maintained in culture up to 2 weeks. During cell culture, we evaluated cell morphology, proliferation, cell motility and the expression of a panel of 89 mesenchymal stem cells’ specific genes, as well as intracellular structures organization. Our results show that mesenchymal stem cells adhered and grew in the 3D Nichoid with a comparable proliferation rate as compared to flat substrates. After seeding on flat substrates, cells displayed large and spread nucleus and cytoplasm, while cells cultured in the 3D Nichoid were spatially organized in three dimensions, with smaller and spherical nuclei. Gene expression analysis revealed the upregulation of genes related to stemness and to mesenchymal stem cells’ features in Nichoid-cultured cells, as compared to flat substrates. The observed changes in cytoskeletal organization of cells cultured on 3D Nichoids were also responsible for a different localization of the mechanotransducer transcription factor YAP, with an increase of the cytoplasmic retention in cells cultured in the 3D Nichoid. This difference could be explained by alterations in the import of transcription factors inside the nucleus due to the observed decrease of mean nuclear pore diameter, by transmission electron microscopy. Our data show that 3D distribution of cell volume has a profound effect on mesenchymal stem cells structure and on their mechanobiological response, and highlight the potential use of the 3D Nichoid substrate to strengthen the potential effects of MSC in vitro and in vivo.

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