scholarly journals Differential effects of commensal bacteria on progenitor cell adhesion, division symmetry and tumorigenesis in the Drosophila intestine

2019 ◽  
Author(s):  
Meghan Ferguson ◽  
Kristina Petkau ◽  
Minjeong Shin ◽  
Anthony Galenza ◽  
David Fast ◽  
...  
Keyword(s):  
Stem Cell ◽  
Cell Growth ◽  
Progenitor Cell ◽  
Lactobacillus Brevis ◽  
Commensal Bacteria ◽  
Rapid Expansion ◽  
Regulatory Pathways ◽  
Stem Cell Divisions ◽  
Stem Cell Populations ◽  
The Impact

ABSTRACTMicrobial factors influence homeostatic and oncogenic growth in the intestinal epithelium. However, we know little about immediate effects of commensal bacteria on stem cell division programs. In this study, we examined effects of commensal Lactobacillus species on homeostatic, and tumorigenic stem cell growth in the Drosophila intestine. We identified Lactobacillus brevis as a potent stimulator of stem cell growth. In a wildtype midgut, Lactobacillus brevis activates growth regulatory pathways that drive stem cell divisions. In a Notch-deficient background, Lactobacillus brevis-mediated growth causes rapid expansion of mutant progenitors, leading to accumulation of large, multi-layered tumors throughout the midgut. Mechanistically, we showed that Lactobacillus brevis disrupts expression and subcellular distribution of progenitor cell integrins, supporting symmetric divisions that expand intestinal stem cell populations. Collectively, our data emphasize the impact of commensal microbes on growth and maintenance of the intestinal progenitor compartment.

scholarly journals Differential effects of commensal bacteria on progenitor cell adhesion, division symmetry and tumorigenesis in the Drosophila intestine

Development ◽  
2021 ◽  
Vol 148 (5) ◽  
Author(s):  
Meghan Ferguson ◽  
Kristina Petkau ◽  
Minjeong Shin ◽  
Anthony Galenza ◽  
David Fast ◽  
...  
Keyword(s):  
Stem Cell ◽  
Progenitor Cell ◽  
Lactobacillus Brevis ◽  
Commensal Bacteria ◽  
Rapid Expansion ◽  
Lactobacillus Species ◽  
Regulatory Pathways ◽  
Cell Divisions ◽  
Stem Cell Divisions ◽  
The Impact

ABSTRACT Microbial factors influence homeostatic and oncogenic growth in the intestinal epithelium. However, we know little about immediate effects of commensal bacteria on stem cell division programs. In this study, we examined the effects of commensal Lactobacillus species on homeostatic and tumorigenic stem cell proliferation in the female Drosophila intestine. We identified Lactobacillus brevis as a potent stimulator of stem cell divisions. In a wild-type midgut, L.brevis activates growth regulatory pathways that drive stem cell divisions. In a Notch-deficient background, L.brevis-mediated proliferation causes rapid expansion of mutant progenitors, leading to accumulation of large, multi-layered tumors throughout the midgut. Mechanistically, we showed that L.brevis disrupts expression and subcellular distribution of progenitor cell integrins, supporting symmetric divisions that expand intestinal stem cell populations. Collectively, our data emphasize the impact of commensal microbes on division and maintenance of the intestinal progenitor compartment.

Effect of stem cell factor on leukemic progenitor cell growth and sensitivity to cytosine-arabinoside

1996 ◽  
Vol 20 (11-12) ◽  
pp. 915-923 ◽  
Author(s):  
Jean-François Viallard ◽  
Christophe Grosset ◽  
Francis Lacombe ◽  
Selva David ◽  
François-Xavier Mahon ◽  
...  
Keyword(s):  
Stem Cell ◽  
Cell Growth ◽  
Cytosine Arabinoside ◽  
Stem Cell Factor ◽  
Progenitor Cell

Oxygen Availability and Stem Cells: Impact On Development and Disease

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. SCI-37-SCI-37
Author(s):  
M. Celeste Simon
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Progenitor Cells ◽  
Conflicts Of Interest ◽  
Hypoxia Inducible Factor ◽  
Stem And Progenitor Cells ◽  
Adult Hippocampus ◽  
Underlying Mechanisms ◽  
Stem Cell Populations ◽  
The Impact

Abstract Abstract SCI-37 Stem and progenitor cells reside in specialized microenvironments that regulate their function. While some stem/progenitor cells are perivascular, others clearly occupy hypoxic niches and may be regulated by O2 gradients. We are currently evaluating underlying mechanisms for the impact of O2 levels on stem and progenitor cells within distinct microenvironments. We have previously shown that neural stem cells within the adult hippocampus are closely associated with low O2 regions and that hypoxia-inducible factor 1α (HIF-1α), a principle mediator of hypoxic adaptations, modulates Wnt-β catenin signaling to maintain stem cell proliferation, differentiation, and neuronal maturation. We have extended these findings to other stem cell populations, such as those of adult muscle and bone marrow. Our findings will be presented at this meeting. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Healthy ageing and spermatogenesis

Reproduction ◽  
2021 ◽  
Vol 161 (4) ◽  
pp. R89-R101
Author(s):  
Eva Pohl ◽  
Jörg Gromoll ◽  
Joachim Wistuba ◽  
Sandra Laurentino
Keyword(s):  
Stem Cell ◽  
Germ Cells ◽  
Current Knowledge ◽  
Hormone Secretion ◽  
Healthy Ageing ◽  
Hormone Production ◽  
Male Germ Cells ◽  
Cell Niche ◽  
Stem Cell Populations ◽  
The Impact

Delayed family planning and increased parental age increase the risk for infertility and impaired offspring health. While the impact of ageing on oogenesis is well studied, this is less understood on spermatogenesis. Assessing ageing effects on the male germline presents a challenge in differentiating between the effects of ageing-associated morbidities, infertility and ‘pure’ ageing. However, understanding the impact of ageing on male germ cells requires the separation of age from other factors. In this review, we therefore discuss the current knowledge on healthy ageing and spermatogenesis. Male ageing has been previously associated with declining sperm parameters, disrupted hormone secretion and increased time-to-pregnancy, among others. However, recent data show that healthy ageing does not deteriorate testicular function in terms of hormone production and spermatogenic output. In addition, intrinsic, age-dependent, highly specific processes occur in ageing germ cells that are clearly distinct from somatic ageing. Changes in spermatogonial stem cell populations indicate compensation for stem cell exhaustion. Alterations in the stem cell niche and molecular ageing signatures in sperm can be observed in ageing fertile men. DNA fragmentation rates as well as changes in DNA methylation patterns and increased telomere length are hallmarks of ageing sperm. Taken together, we propose a putative link between the re-activation of quiescent Adark spermatogonia and molecular changes in aged sperm descending from these activated spermatogonia. We suggest a baseline of ‘pure' age effects in male germ cells which can be used for subsequent studies in which the impact of infertility or co-morbidities will be studied.

scholarly journals Stem cell factor and basic fibroblast growth factor are synergistic in augmenting committed myeloid progenitor cell growth

Blood ◽  
1994 ◽  
Vol 83 (4) ◽  
pp. 907-910 ◽  
Author(s):  
JL Gabrilove ◽  
K White ◽  
Z Rahman ◽  
EL Wilson
Keyword(s):  
Bone Marrow ◽  
Stem Cell ◽  
Growth Factor ◽  
Cell Growth ◽  
Fibroblast Growth Factor ◽  
Stromal Cells ◽  
Stem Cell Factor ◽  
Progenitor Cell ◽  
Fibroblast Growth ◽  
Gm Csf

Abstract Stem cell factor (SCF) and basic fibroblast growth factor (bFGF) are hematopoietic cytokines produced by bone marrow stromal cells. It is known that, although SCF and bFGF have limited clonogenic activity on their own, they can augment colony-stimulating factor (CSF)-mediated progenitor cell growth. Because these factors are both sequestered by stromal cells, we examined their interaction on progenitor cell growth in conjunction with granulocyte-macrophage-CSF (GM-CSF). In this study, we show that clonogenic growth derived from low-density bone marrow cells stimulated by GM-CSF is significantly augmented (P < .001) in the presence of maximal (100 ng/mL) concentrations of SCF in combination with 100 ng/mL of bFGF. When CD34+ cells are used, the synergistic effect of bFGF and SCF for GM-CSF-mediated progenitor cell growth is further increased, resulting in as much as a sevenfold increase in detectable colony-forming units granulocyte-macrophage (P < .001). These data suggest that the synergistic activity of bFGF and SCF is mediated directly on hematopoietic precursors. These observations suggest that bFGF and SCF, concentrated locally on stromal cell surfaces, might interact in concert with other hematopoietic cytokines to regulate stem cell proliferation and differentiation in hematopoietic niches in the bone marrow.

scholarly journals In vitro megakaryocytopoietic and thrombopoietic activity of c-mpl ligand (TPO) on purified murine hematopoietic stem cells

Blood ◽  
1994 ◽  
Vol 84 (12) ◽  
pp. 4045-4052 ◽  
Author(s):  
FC Zeigler ◽  
F de Sauvage ◽  
HR Widmer ◽  
GA Keller ◽  
C Donahue ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Hematopoietic Stem Cell ◽  
Progenitor Cell ◽  
Fetal Liver ◽  
Cell Suspension Cultures ◽  
Hematopoietic Stem ◽  
Kit Ligand ◽  
Stem Cell Populations

Recently, the ligand for c-mpl has been identified and cloned. Initial studies of this molecule indicate that it is the platelet regulatory factor, thrombopoietin (TPO). Previous work has indicated that c-mpl is expressed in very immature hematopoietic precursors and thus raised the possibility that TPO may act directly on the hematopoietic stem cell. Therefore, in these studies, we investigate the effects of TPO on hematopoietic stem cell populations isolated from the murine fetal liver and bone marrow. Cocultivation of stem cells with fetal liver stroma give rise to multilineage expansion of the stem cells but with little or no megakaryocytopoiesis. Addition of TPO to these cocultures gives significant megakaryocyte production. This production is enhanced in combination with Kit ligand or interleukin-3. The addition of TPO to stem cell suspension cultures produces a dynamic thrombopoietic system in which stem cells undergo differentiation to produce megakaryocytes and proplatelets. These experiments show that the megakaryocytopoietic and thrombopoietic activities of TPO are initiated at the level of an early progenitor cell or upon the hematopoietic stem cell.

scholarly journals Reoccurring neural stem cell divisions in the adult zebrafish telencephalon are sufficient for the emergence of aggregated spatiotemporal patterns

PLoS Biology ◽  
2020 ◽  
Vol 18 (12) ◽  
pp. e3000708
Author(s):  
Valerio Lupperger ◽  
Carsten Marr ◽  
Prisca Chapouton
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Stem Cell ◽  
Neural Stem Cell ◽  
Agent Based ◽  
Brain Hemispheres ◽  
Random Fashion ◽  
Dividing Cells ◽  
Stem Cell Divisions ◽  
Stem Cell Populations

Regulation of quiescence and cell cycle entry is pivotal for the maintenance of stem cell populations. Regulatory mechanisms, however, are poorly understood. In particular, it is unclear how the activity of single stem cells is coordinated within the population or if cells divide in a purely random fashion. We addressed this issue by analyzing division events in an adult neural stem cell (NSC) population of the zebrafish telencephalon. Spatial statistics and mathematical modeling of over 80,000 NSCs in 36 brain hemispheres revealed weakly aggregated, nonrandom division patterns in space and time. Analyzing divisions at 2 time points allowed us to infer cell cycle and S-phase lengths computationally. Interestingly, we observed rapid cell cycle reentries in roughly 15% of newly born NSCs. In agent-based simulations of NSC populations, this redividing activity sufficed to induce aggregated spatiotemporal division patterns that matched the ones observed experimentally. In contrast, omitting redivisions leads to a random spatiotemporal distribution of dividing cells. Spatiotemporal aggregation of dividing stem cells can thus emerge solely from the cells’ history.

Abstract 15440: Dynamics of Adipocyte and Endothelial Progenitor Cell Pools in Expanding Adipose Tissue

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Candice R Holden ◽  
Marcin Wysoczynski ◽  
Brian Sansbury ◽  
Jason Hellmann ◽  
Nagma Zafar ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Adipose Tissue ◽  
Stem Cell ◽  
Progenitor Cells ◽  
Progenitor Cell ◽  
Stromal Vascular Fraction ◽  
Cell Populations ◽  
Adipose Organ ◽  
The Impact

Objective: Obesity is a major risk factor for the development of several chronic diseases including type 2 diabetes and cardiovascular disease. Proper fat storage in white adipose tissue (WAT) is required to maintain insulin sensitivity and to preserve (cardio)vascular health. We hypothesize that endothelial and adipocyte progenitor cell populations (EPCs and APCs, respectively) must be appropriately balanced for physiological, as opposed to pathological, remodeling of WAT. Methods and Results: To determine the impact of nutrient excess on stem/progenitor cells in epididymal WAT, male C57BL/6J mice were placed on a high fat diet (HFD; 60% fat) for 12 weeks and changes in WAT stem cell populations were measured in the stromal vascular fraction by flow cytometry. Although the APC (CD24+/CD29+/Sca+/CD14-/CD45-) population, which has the capacity to differentiate into adipocytes both in vitro and in vivo , was not significantly changed with diet, Flk+/Sca+ EPCs were diminished, promoting a 4-fold decrease in the EPC/APC ratio (p <0.05, n = 6/group). To determine whether this deficit may be due to poor stem cell recruitment, mice were irradiated, and the bone marrow was repopulated with GFP+ donor marrow. The transplanted mice were then placed on a low fat diet (LFD; 10% fat) or HFD for 12 weeks, and WAT progenitor cells were again measured. Greater than 95% of the putative APCs in the WAT of HF-fed mice were GFP+ (p<0.0001, n=7-8/group), indicating a bone marrow-derived origin. Unexpectedly, less than 1% of the EPCs were GFP+ (p<0.001, n=7-8/group), which suggests that EPCs present in WAT are not derived from bone marrow in adult mice. Confocal analysis of WAT from HF-fed, bone marrow-transplanted mice showed little evidence of significant APC differentiation into triglyceride-laden adipocytes, suggesting that conditions associated with nutrient excess may impair the ability of the adipose organ to store fat properly. Conclusions: These results demonstrate that putative APCs, and not EPCs, in epididymal WAT are derived from bone marrow. Furthermore, our data suggest that conditions of nutrient excess promote an imbalance in EPCs and APCs, the stoichiometry of which may be critical for the development of new adipocytes and for proper storage of fat.

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