scholarly journals Poly(ADP-ribosyl)ating pathway regulates development from stem cell niche to longevity control

2021 ◽  
Vol 5 (3) ◽  
pp. e202101071
Author(s):  
Guillaume Bordet ◽  
Elena Kotova ◽  
Alexei V Tulin
Keyword(s):  
Posttranslational Modification ◽  
Stem Cell Niche ◽  
Egg Production ◽  
Phosphorylation Sites ◽  
Germline Stem Cells ◽  
Protein Activity ◽  
Cell Niche ◽  
Sufficient Food ◽  
Embryonic And Larval Development

The regulation of poly(ADP-ribose) polymerase, the enzyme responsible for the synthesis of homopolymer ADP-ribose chains on nuclear proteins, has been extensively studied over the last decades for its involvement in tumorigenesis processes. However, the regulation of poly(ADP-ribose) glycohydrolase (PARG), the enzyme responsible for removing this posttranslational modification, has attracted little attention. Here we identified that PARG activity is partly regulated by two phosphorylation sites, ph1 and ph2, in Drosophila. We showed that the disruption of these sites affects the germline stem-cells maintenance/differentiation balance as well as embryonic and larval development, but also the synchronization of egg production with the availability of a calorically sufficient food source. Moreover, these PARG phosphorylation sites play an essential role in the control of fly survivability from larvae to adults. We also showed that PARG is phosphorylated by casein kinase 2 and that this phosphorylation seems to protect PARG protein against degradation in vivo. Taken together, these results suggest that the regulation of PARG protein activity plays a crucial role in the control of several developmental processes.

MESENCHYMAL TNFR1 EXPRESSION PRESERVES THE COLONIC EPITHELIAL STEM CELL NICHE

2021 ◽  
Vol 27 (Supplement_1) ◽  
pp. S7-S8
Author(s):  
Safina Gadeock ◽  
Cambrian Liu ◽  
Brent Polk
Keyword(s):  
Stem Cell ◽  
Stem Cell Niche ◽  
Mesenchymal Cells ◽  
Epithelial Stem Cells ◽  
Epithelial Stem Cell ◽  
Long Term Treatment ◽  
Lgr5 Expression ◽  
Cell Niche

Abstract Tumor necrosis factor (TNF) is a highly expressed cytokine in inflammatory bowel disease (IBD). Although TNF can induce colonic epithelial dysfunction and apoptosis, recent studies suggest that TNF signalling promotes epithelial wound repair and stem cell function. Here we investigated the role of TNF receptor 1 (TNFR1) in mediating TNF’s effects on colonic epithelial stem cells, integral to mucosal healing in colitis. We demonstrate that Tnfr1-/- mice exhibit loss in Lgr5 expression (-52%, p<0.02; N=6) compared to wildtype (WT) controls. However, the opposite result was found in vitro, wherein murine Tnfr1-/- colonoids demonstrated a significant increase in Lgr5 expression (66%, p<0.007; N=6) compared to WT colonoids. Similarly, human colonoids treated with an anti-TNFR1 antibody also demonstrated an increase in Lgr5 expression, relative to IgG controls. To resolve the contradiction in the in vivo versus in vitro environment, we hypothesized that mesenchymal TNFR1 expression regulates the epithelial stem cell niche. To determine the relationships between these cell types, we co-cultured WT or Tnfr1-/- colonoids with WT or Tnfr1-/- colonic myofibroblasts (CMFs). We found that epithelial Lgr5 expression was significantly higher (by 52%, p<0.05; N=3) when co-cultured with WT compared to TNFR1-/- myofibroblasts. The loss of TNFR1 expression in vivo increases the number of αSMA+ mesenchymal cells by nearly 56% (N=6) but considerably reduces the pericryptal PDGFRα+ cells, suggesting modifications in mesenchymal populations that contribute to the epithelial stem cell niche. Functionally, primary Tnfr1-/--CMFs displayed PI3k (p<0.001; N=3) and MAPK (p<0.01; N=3)-dependent increases in migration, proliferation, and differentiation, but RNA profiling demonstrated by diminished levels of stem cell niche factors, Rspo3 (-80%, p<0.0001; N=6) and Wnt2b (-63%, p<0.008; N=6) compared to WT-CMFs. Supplementation with 50ng recombinant Rspo3 for 5 d to Lgr5-GFP organoids co-cultured with TNFR1-/--CMFs restored Lgr5 expression to wildtype levels. Therefore, TNFR1-mediated TNF signalling in mesenchymal cells promotes their ability to support an epithelial stem cell niche. These results should motivate future studies of the stem cell niche in the context of long-term treatment with anti-TNF therapies.

scholarly journals Lymphatic vessels interact dynamically with the hair follicle stem cell niche during skin regeneration in vivo

2019 ◽  
Vol 38 (19) ◽  
Author(s):  
Daniel Peña‐Jimenez ◽  
Silvia Fontenete ◽  
Diego Megias ◽  
Coral Fustero‐Torre ◽  
Osvaldo Graña‐Castro ◽  
...  
Keyword(s):  
Stem Cell ◽  
Hair Follicle ◽  
Stem Cell Niche ◽  
Lymphatic Vessels ◽  
Skin Regeneration ◽  
Hair Follicle Stem Cell ◽  
Cell Niche

scholarly journals The bone metastasis niche in breast cancer: potential overlap with the haematopoietic stem cell niche in vivo

2019 ◽  
Vol 17 ◽  
pp. 100244 ◽  
Author(s):  
Gloria Allocca ◽  
Russell Hughes ◽  
Ning Wang ◽  
Hannah K Brown ◽  
Penelope D Ottewell ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Stem Cell ◽  
Bone Metastasis ◽  
Stem Cell Niche ◽  
Haematopoietic Stem Cell ◽  
Cell Niche

scholarly journals Birth and delineation of the intestinal stem cell niche

2021 ◽  
Author(s):  
Neil McCarthy ◽  
Guodong Tie ◽  
Shariq Madha ◽  
Adrianna Maglieri ◽  
Judith Kraiczy ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Critical Period ◽  
Stem Cell Niche ◽  
De Novo ◽  
Cell Types ◽  
Muscle Layer ◽  
Intestinal Stem Cells ◽  
Morphogenetic Protein ◽  
Cell Niche

Wnt and Rspondin (RSPO) signaling triggers proliferation, and bone morphogenetic protein inhibitors (BMPi) impede differentiation, of intestinal stem cells (ISCs). Here we report that the functional ISC niche is a complex, multi-layered mesenchymal structure that includes distinct smooth muscle populations and describe how that niche organizes early in mouse life. Diverse sub-cryptal cells provide redundant supportive factors, with distinct BMPi and the most potent Wnt agonist, RSPO2, restricted to single cell types. Two functionally opposing elements arise in tandem during a critical period of crypt morphogenesis: a prominent shelf of BMP+ sub-epithelial myofibroblasts that promote epithelial differentiation and the muscularis mucosae, a specialized muscle layer generated de novo to supplement other RSPO and BMPi sources. In vivo ablation of smooth muscle, while preserving trophocytes, raises crypt BMP activity and potently limits crypt expansion. Thus, distinct and progressively refined mesenchymal components together create the milieu necessary to propagate crypts during rapid organ growth and to sustain ISCs in the adult niche.

scholarly journals Quantitative proteomics reveals extensive lysine ubiquitination in the Arabidopsis root proteome and uncovers novel transcription factor stability states

2021 ◽  
Author(s):  
Gaoyuan Song ◽  
Damilola Olatunji ◽  
Christian Montes ◽  
Natalie M Clark ◽  
Yunting Pu ◽  
...  
Keyword(s):  
Posttranslational Modification ◽  
Site Directed Mutagenesis ◽  
Biological Processes ◽  
Protein Activity ◽  
Helix Loop Helix ◽  
Primary Roots ◽  
Lysine Residues ◽  
Ubiquitin Proteasome ◽  
The Stability

Protein activity, abundance, and stability can be regulated by posttranslational modification including ubiquitination. Ubiquitination is conserved among eukaryotes and plays a central role in modulating cellular function and yet we lack comprehensive catalogs of proteins that are modified by ubiquitin in plants. In this study, we describe an antibody-based approach to enrich peptides containing the di-glycine (diGly) remnant of ubiquitin and coupled that with isobaric labeling to enable quantification, from up to 16-multiplexed samples, for plant tissues. Collectively, we identified 7,130 diGly-modified lysine residues sites arising from 3,178 proteins in Arabidopsis primary roots. These data include ubiquitin proteasome dependent ubiquitination events as well as ubiquitination events associated with auxin treatment. Gene Ontology analysis indicated that ubiquitinated proteins are associated with numerous biological processes including hormone signaling, plant defense, protein homeostasis, and root morphogenesis. We determined the ubiquitinated lysine residues that directly regulate the stability of the transcription factors CRYPTOCHROME-INTERACTING BASIC-HELIX-LOOP-HELIX 1 (CIB1), CIB1 LIKE PROTEIN 2 (CIL2), and SENSITIVE TO PROTON RHIZOTOXICITY (STOP1) using site directed mutagenesis and in vivo degradation assays. These comprehensive site-level ubiquitinome profiles provide a wealth of data for future studies related to modulation of biological processes mediated by this posttranslational modification in plants.

Ectopic Human Mesenchymal Stem Cell-Coated Scaffolds Create An In Vivo Leukemia Niche in NOD/SCID Mice.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 559-559
Author(s):  
Sarah Rivkah Vaiselbuh ◽  
Morris Edelman ◽  
Jeffrey Michael Lipton ◽  
Johnson M. Liu
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Stem Cell ◽  
Stem Cell Niche ◽  
Scid Mice ◽  
Cxcr4 Antagonist ◽  
Cell Niche

Abstract Abstract 559 Introduction: Different cellular components of the normal hematopoietic niche have been identified. However, the niche for malignant hematopoiesis remains to be elucidated. Recent work of other groups has suggested that hematopoietic stem cells (HSC) within the bone marrow anchor themselves in place by attaching to osteoblasts and/or vascular sinusoid endothelial cells. We have recently identified mesenchymal stem cells (MSC) as niche-maker cells and found a crucial role of the SDF-1/CXCR4 axis in this process. Stromal Derived Factor-1 (SDF-1/CXCL12) regulates stem cell trafficking and the cell cycle via its receptor CXCR4. Methods: Polyurethane scaffolds, coated in vitro with human bone marrow MSC, were implanted subcutaneously in non-irradiated NOD/SCID mice. CD34+ HSC or primary AML cells (from a leukapheresis product) were injected either in situ or retro-orbitally in the mice and analyzed for engraftment. The mice were treated twice per week with in situ injections of SDF-1, AMD3100 (a CXCR4 antagonist) or PBS (control). After 2 to 4 weeks, the scaffolds were processed and evaluated for cell survival in the mesenchymal niche by immunohistochemistry. Results: We created in vitro MSC-coated scaffolds that retained inoculated AML cells in the presence of SDF-1, while AML cells seeded on empty scaffolds were not retained. In vivo in NOD/SCID mice, the MSC-coated scaffolds, in the presence of SDF-1 enabled homing of both in situ injected normal CD34+ HSC and retroorbital- or in situ injected primary human AML cells. The scaffolds were vascularized and showed osteoclasts and adipocytes present, suggestive of an ectopic human bone marrow microenvironment in the murine host. Finally, the SDF-1-treated scaffolds showed proliferation of the MSC stromal layer with multiple adherent AML cells, while in the AMD3100-treated scaffolds the stromal lining was thin and disrupted at several points, leaving AML cells free floating in proximity. The PBS-treated control-scaffold showed a thin single cell MSC stromal layer without disruption, with few AML cells attached. Conclusion: The preliminary data of this functional ectopic human microenvironment in NOD/SCID mice suggest that AMD3100 (a CXCR4 antagonist) can disrupt the stem cell niche by modulation of the mesenchymal stromal. Further studies are needed to define the role of mesenchymal stem cells in maintaining the hematopoietic/leukemic stem cell niche in vivo. In Vivo Leukemia Stem Cell Niche: (A) Empty polyurethane scaffold. (B)Vascularization in SQ implanted MSC-coated scaffold (s) niche in NOD/SCID mice. (C) DAB Peroxidase (brown) human CD45 positive nests of AML cells (arrows) 1 week after direct in situ AML injection. (D) Human CD45 positive myeloid cells adhere to MSC in vivo (arrows). Disclosures: No relevant conflicts of interest to declare.

New Method for in Vivo Hematopoiesis Microenvironment Research: Tissue-Engineering-Bone Femur Repairing Model and Semi-Solid Decalcification

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 4732-4732
Author(s):  
Shan Jiang ◽  
Qianli Jiang ◽  
Liqiong Zhu ◽  
Feili Chen ◽  
Lezhong Yuan ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Stem Cell Niche ◽  
Conflicts Of Interest ◽  
Hematopoietic Cells ◽  
Marrow Cavity ◽  
Cell Matrix ◽  
Cell Niche ◽  
Semi Solid ◽  
The Relationship

Abstract Abstract 4732 Background: Bone defection repairing is a good model to study the hematopoiesis and its environment, during which there are reformations of niches and marrow cavity, different cells' migrations and evolutions, etc. Tissue-engineering-bone (TEB) is a kind of scaffold that degrades gradually during bone reformation. In order to observe different cells growing within the rigid, opaque, friable and porous TEB, we established a novel technique named semi-solid decalcification (SSD). Aim: With the TEB repairing model, we hope to address 3 questions: Firstly, could a functional bone with marrow cavity be reformed with the TEB? Secondly, what are the contributions of cells within and outside the TEB? Thirdly, how do the hematopoietic cells cross-talking with the microenvironment during bone reformation? Method: Results: Conclusion: This eGFP-to-mRFP transgenic mice femur repairing model was proved, at least in principle, to be efficient to mimic the reforming of bone marrow and stem cell niche. With the help of SSD, we can easily study the relationship and cross-talking of cell-cell and cell-matrix in a 3-D pattern, which is of the most important to understand the mechanism of hematopoiesis microenvironment. However, further researches are carrying on, to exclude the possible mixture of eGFP+ hematopoietic cells into mesenchymal cells before TEB-MC-GFP implantation and to better identify the subtypes of existing cells within the TEB. PS: Thanks to the support of NSFC (No.30901367, 31070866). Disclosures: No relevant conflicts of interest to declare.

scholarly journals The Drosophila ZO-1 protein Polychaetoid suppresses Deltex-regulated Notch activity to modulate germline stem cell niche formation

Open Biology ◽  
2017 ◽  
Vol 7 (4) ◽  
pp. 160322 ◽  
Author(s):  
Hideyuki Shimizu ◽  
Marian B. Wilkin ◽  
Simon A. Woodcock ◽  
Alessandro Bonfini ◽  
Yvonne Hung ◽  
...  
Keyword(s):  
Stem Cell ◽  
Cell Surface ◽  
Stem Cell Niche ◽  
Activation Mechanism ◽  
Germline Stem Cell ◽  
Ligand Interaction ◽  
Alternative Means ◽  
Cell Niche ◽  
Notch Activation

The developmental signalling protein Notch can be proteolytically activated following ligand-interaction at the cell surface, or can be activated independently of its ligands, following Deltex (Dx)-induced Notch endocytosis and trafficking to the lysosomal membrane. The means by which different pools of Notch are directed towards these alternative outcomes remains poorly understood. We found that the Drosophila ZO-1 protein Polychaetoid (Pyd) suppresses specifically the Dx-induced form of Notch activation both in vivo and in cell culture assays. In vivo we confirmed the physiological relevance and direction of the Pyd/Dx interaction by showing that the expanded ovary stem cell niche phenotypes of pyd mutants require the presence of functional Dx and other components that are specific to the Dx-induced Notch activation mechanism. In S2 cells we found that Pyd can form a complex with Dx and Notch at the cell surface and reduce Dx-induced Notch endocytosis. Similar to other known activities of ZO-1 family proteins, the action of Pyd on Dx-induced endocytosis and signalling was found to be cell density dependent. Thus, together, our results suggest an alternative means by which external cues can tune Notch signalling through Pyd regulation of Dx-induced Notch trafficking.

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