scholarly journals Aneuploidy promotes intestinal dysplasia in Drosophila

2018 ◽  
Author(s):  
Luís Pedro Resende ◽  
Augusta Monteiro ◽  
Rita Brás ◽  
Tatiana Lopes ◽  
Claudio E. Sunkel

AbstractAneuploidy is associated with different human diseases, particularly cancer, but how different cell types within tissues respond to aneuploidy is not fully understood. In some studies, aneuploidy has been shown to have a deleterious effect and lead to cell death, however it has also been shown to be a causal event of tumorigenesis in other contexts.Here, we show that Drosophila intestinal stem cells have a particular tolerance to aneuploidy and do not activate apoptosis in response to chromosome misegregation like other non-stem cells. Instead, we observe the development of tissue dysplasia characterized by an accumulation of progenitor cells, increased stem cell proliferation rate, and an excess of cells of the enteroendocrine lineage. Our findings highlight the importance of mechanisms acting to prevent aneuploidy within tissue stem cells and provide an in vivo model of how these cells can act as reservoirs for genomic alterations that can lead to dysplasia.

2017 ◽  
Vol 216 (8) ◽  
pp. 2231-2231
Author(s):  
Ben Short

Mitochondrial turnover regulates stem cell proliferation and tissue homeostasis in Drosophila intestines.


2021 ◽  
Author(s):  
Anna Kim ◽  
Amanda Nguyen ◽  
Marco Marchetti ◽  
Denise Montell ◽  
Beth Pruitt ◽  
...  

Cytosolic calcium is a highly dynamic, tightly regulated, and broadly conserved cellular signal. Calcium dynamics have been studied widely in cellular monocultures, yet in vivo most organs comprise heterogeneous populations of stem and differentiated cells. We examined calcium dynamics in each cell type of the adult Drosophila intestine, a self-renewing epithelial organ where multipotent stem cells give rise to mature absorptive enterocytes and secretory enteroendocrine cells. Here we perform live imaging of whole organs ex vivo, and we employ orthogonal expression of red and green calcium sensors to determine whether calcium oscillations between different cell types are coupled. We show that stem cell daughters adopt strikingly distinct patterns of calcium oscillations when they acquire their terminal fates: enteroendocrine cells exhibit single-cell calcium oscillations, while long-range calcium waves propagate rhythmically across large fields of enterocytes. These multicellular waves do not propagate through progenitor cells (stem cells and undifferentiated enterocyte precursors), whose oscillation frequency is approximately half that of enteroendocrine cells. Organ-scale inhibition of gap junctions eliminates calcium oscillations in all three cell types, even, intriguingly, in progenitor and enteroendocrine cells that are surrounded only by enterocytes. Our findings establish that cells adopt fate-specific modes of calcium dynamics as they terminally differentiate and reveal that the oscillatory dynamics of different cell types in the same epithelium are paced independently.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Smitha Rao ◽  
Chienwen Huang ◽  
Uday Tata ◽  
Peter Wu ◽  
Nikhil Arora ◽  
...  

Nanoparticles (NPs) have been introduced as a suitable alternative in manyin vivobioapplications. The risks of utilizing nanoparticles continue to be an ongoing research. Furthermore, the various chemicals used in their synthesis influence the cytotoxic effects of nanoparticles. We have investigated the cytotoxicity of Porous Hollow Au Nanoparticles (PHAuNPs) on cancer cell lines PC-3, PC-3ML, and MDA-MB-231 and the normal cell line PNT1A. Cell proliferation for the different cells in the presence of different concentrations of the PHAuNPs was assessed after 24 hours and 72 hours of incubation using MTT assay. The study also included the cytotoxic evaluation of pegylated PHAuNPs. Identical cell seeding densities, particle concentrations, and incubation times were employed for these two types of Au nanoparticles. Our results indicated that (1) impact on cell proliferation was concentration dependent and was different for the different cell types without cellular necrosis and (b) cellular proliferation might be impacted more based on the cell line.


2018 ◽  
Vol 217 (11) ◽  
pp. 3930-3946 ◽  
Author(s):  
Luís Pedro Resende ◽  
Augusta Monteiro ◽  
Rita Brás ◽  
Tatiana Lopes ◽  
Claudio E. Sunkel

Aneuploidy is associated with different human diseases including cancer. However, different cell types appear to respond differently to aneuploidy, either by promoting tumorigenesis or causing cell death. We set out to study the behavior of adult Drosophila melanogaster intestinal stem cells (ISCs) after induction of chromosome missegregation either by abrogation of the spindle assembly checkpoint or through kinetochore disruption or centrosome amplification. These conditions induce moderate levels of aneuploidy in ISCs, and we find no evidence of apoptosis. Instead, we observe a significant accumulation of ISCs associated with increased stem cell proliferation and an excess of enteroendocrine cells. Moreover, aneuploidy causes up-regulation of the JNK pathway throughout the posterior midgut, and specific inhibition of JNK signaling in ISCs is sufficient to prevent dysplasia. Our findings highlight the importance of understanding the behavior of different stem cell populations to aneuploidy and how these can act as reservoirs for genomic alterations that can lead to tissue pathologies.


Author(s):  
Prithiv K R Kumar

Renal failure is a major health problem. The mortality rate remain high despite of several therapies. The most complex of the renal issues are solved through stem cells. In this review, different mechanism for cure of chronic kidney injury along with cell engraftment incorporated into renal structures will be analysed. Paracrine activities of embryonic or induced Pluripotent stem cells are explored on the basis of stem cell-induced kidney regeneration. Several experiments have been conducted to advance stem cells to ensure the restoration of renal functions. More vigour and organised protocols for delivering stem cells is a possibility for advancement in treatment of renal disease. Also there is a need for pressing therapies to replicate the tissue remodelling and cellular repair processes suitable for renal organs. Stem cells are the undifferentiated cells that have the ability to multiply into several cell types. In vivo experiments on animal’s stem cells have shown significant improvements in the renal regeneration and functions of organs. Nevertheless more studies show several improvements in the kidney repair due to stem cell regeneration.


Biomolecules ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1074
Author(s):  
Giuseppina Divisato ◽  
Silvia Piscitelli ◽  
Mariantonietta Elia ◽  
Emanuela Cascone ◽  
Silvia Parisi

Embryonic stem cells (ESCs) have the extraordinary properties to indefinitely proliferate and self-renew in culture to produce different cell progeny through differentiation. This latter process recapitulates embryonic development and requires rounds of the epithelial–mesenchymal transition (EMT). EMT is characterized by the loss of the epithelial features and the acquisition of the typical phenotype of the mesenchymal cells. In pathological conditions, EMT can confer stemness or stem-like phenotypes, playing a role in the tumorigenic process. Cancer stem cells (CSCs) represent a subpopulation, found in the tumor tissues, with stem-like properties such as uncontrolled proliferation, self-renewal, and ability to differentiate into different cell types. ESCs and CSCs share numerous features (pluripotency, self-renewal, expression of stemness genes, and acquisition of epithelial–mesenchymal features), and most of them are under the control of microRNAs (miRNAs). These small molecules have relevant roles during both embryogenesis and cancer development. The aim of this review was to recapitulate molecular mechanisms shared by ESCs and CSCs, with a special focus on the recently identified classes of microRNAs (noncanonical miRNAs, mirtrons, isomiRs, and competitive endogenous miRNAs) and their complex functions during embryogenesis and cancer development.


Author(s):  
Anja Trillhaase ◽  
Marlon Maertens ◽  
Zouhair Aherrahrou ◽  
Jeanette Erdmann

AbstractStem cell technology has been around for almost 30 years and in that time has grown into an enormous field. The stem cell technique progressed from the first successful isolation of mammalian embryonic stem cells (ESCs) in the 1990s, to the production of human induced-pluripotent stem cells (iPSCs) in the early 2000s, to finally culminate in the differentiation of pluripotent cells into highly specialized cell types, such as neurons, endothelial cells (ECs), cardiomyocytes, fibroblasts, and lung and intestinal cells, in the last decades. In recent times, we have attained a new height in stem cell research whereby we can produce 3D organoids derived from stem cells that more accurately mimic the in vivo environment. This review summarizes the development of stem cell research in the context of vascular research ranging from differentiation techniques of ECs and smooth muscle cells (SMCs) to the generation of vascularized 3D organoids. Furthermore, the different techniques are critically reviewed, and future applications of current 3D models are reported. Graphical abstract


Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3389
Author(s):  
Ishtiaq Ahmed ◽  
Saif Ur Rehman ◽  
Shiva Shahmohamadnejad ◽  
Muhammad Anjum Zia ◽  
Muhammad Ahmad ◽  
...  

In humans, various sites like cannabinoid receptors (CBR) having a binding affinity with cannabinoids are distributed on the surface of different cell types, where endocannabinoids (ECs) and derivatives of fatty acid can bind. The binding of these substance(s) triggers the activation of specific receptors required for various physiological functions, including pain sensation, memory, and appetite. The ECs and CBR perform multiple functions via the cannabinoid receptor 1 (CB1); cannabinoid receptor 2 (CB2), having a key effect in restraining neurotransmitters and the arrangement of cytokines. The role of cannabinoids in the immune system is illustrated because of their immunosuppressive characteristics. These characteristics include inhibition of leucocyte proliferation, T cells apoptosis, and induction of macrophages along with reduced pro-inflammatory cytokines secretion. The review seeks to discuss the functional relationship between the endocannabinoid system (ECS) and anti-tumor characteristics of cannabinoids in various cancers. The therapeutic potential of cannabinoids for cancer—both in vivo and in vitro clinical trials—has also been highlighted and reported to be effective in mice models in arthritis for the inflammation reduction, neuropathic pain, positive effect in multiple sclerosis and type-1 diabetes mellitus, and found beneficial for treating in various cancers. In human models, such studies are limited; thereby, further research is indispensable in this field to get a conclusive outcome. Therefore, in autoimmune disorders, therapeutic cannabinoids can serve as promising immunosuppressive and anti-fibrotic agents.


1992 ◽  
Vol 47 (9) ◽  
pp. 1324-1332 ◽  
Author(s):  
Jens Freund ◽  
Afroditi Kapurniotu ◽  
Tadeusz A. Holak ◽  
Maryse Lenfant ◽  
Wolfgang Voelter

The solid phase synthesis of the inhibitor of hematopoietic stem cell proliferation, Ac–Ser–Asp–Lys–Pro–OH, and its derivative Ac–Ala–Asp–Lys–Pro–OH is described. 1H and 13C NMR investigations demonstrate that both peptides show no prefered conformation in water solution. Both peptides exist in a Pro-cis-trans equilibrium ratio of 9 (trans) : 1 (cis). Thymosin β4 is believed to be the precursor molecule of the tetrapeptide Ac–SDKP. The attachement of the random coil tetrapeptide to a rigid helical fragment could facilitate its in vivo enzymatic cleavage.


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