Search results for "Progenitor cell"
showing 10 items of 307 documents
Cellular Response to Spinal Cord Injury in Regenerative and Non-Regenerative Stages in Xenopus Laevis
2020
Abstract Background The efficient regenerative abilities at larvae stages followed by a non-regenerative response after metamorphosis in froglets makes Xenopus an ideal model organism to understand the cellular responses leading to spinal cord regeneration. Methods We compared the cellular response to spinal cord injury between the regenerative and non-regenerative stages of Xenopus laevis. For this analysis, we used electron microscopy, immunofluorescence and histological staining of the extracellular matrix. We generated two transgenic lines: i) the reporter line with the zebrafish GFAP regulatory regions driving the expression of EGFP, and ii) a cell specific inducible ablation line with…
Inverse PAR1 Activity of Hematopoietic Stem Cells and BM Stromal Cells Mediates G-CSF-Induced Mobilization By Regulation of Nitric Oxide Generation
2016
Abstract Hematopoietic stem and progenitor cell (HSPC) egress from the bone marrow (BM) to the circulation is tightly regulated and is accelerated during stress conditions, a process utilized for BM harvest. Recently, we demonstrated that mouse long term repopulating hematopoietic stem cell (LT-HSC) BM retention and their rapid release to the blood circulation are governed by a switch in nitric oxide (NO) generation via distinct coagulation-related protease activated receptor 1 (PAR1) cascades (Gur-Cohen S. et al., NM, 2016). Herein we report that surface PAR1 expression can be exploited and serve as a positive predictive marker for the efficiency of human CD34+ HSPC mobilization among heal…
Telencephalic-olfactory bulb ventricle wall organization in Austrolebias charrua: Cytoarchitecture, proliferation dynamics, neurogenesis and migratio…
2016
Adult neurogenesis participates in fish olfaction sensitivity in response to environmental challenges. Therefore, we investigated if several populations of stem/progenitor cells that are retained in the olfactory bulbs (OB) may constitute different neurogenic niches that support growth and functional demands. By electron microscopy and combination cell proliferation and lineage markers, we found that the telencephalic ventricle wall (VW) at OB level of Austrolebias charrua fish presents three neurogenic niches (transitional 1, medial 2 and ventral 3). The main cellular types described in other vertebrate neurogenic niches were identified (transient amplifying cells, stem cells and migrating…
Effect of total sonicated Aggregatibacter actinomycetemcomitans fragments on gingival stem/progenitor cells
2018
Background Aggregatibacter-actinomycetemcomitans (A.actinomycetemcomitans) are strongly associated with localized-aggressive-periodontitis (LAgP). The study’s aim was to test for the first time the effect of total sonicated A.actinomycetemcomitans-bacterial-fragments on gingival mesenchymal stem/progenitor cells’ (G-MSCs) proliferation and regenerative gene expression in-vitro. Material and Methods G-MSCs were isolated, characterized, expanded and stimulated by total sonicated A.actinomycetemcomitans-bacterial-fragments (0 (negative-control), 15, 60, 120 and 240µg/ml; serovar-b; n=6/group). Cellular proliferation and NF-κβ (NFKB1), Alkaline Phosphatase (ALPL), Collagen-I (COL1A1), Collagen-…
11q Deletion or ALK Activity Curbs DLG2 Expression to Maintain an Undifferentiated State in Neuroblastoma
2020
High-risk 11q deleted neuroblastomas typically display undifferentiated/poorly differentiated morphology. Neuroblastoma is thought to develop from Schwann cell precursors and undifferentiated neural crest (NC) derived cells. It is therefore vital to understand mechanisms involved in the block of differentiation. We identify an important role for oncogenic ALK-ERK1/2-SP1 signaling in maintenance of undifferentiated NC-derived progenitors via repression of DLG2, a tumor suppressor in neuroblastoma. DLG2 is expressed in the ‘bridge signature’ that represents the transcriptional transition state when neural crest cells or Schwann Cell Precursors become chromaffin cells of the adrenal gland. We …
The HSP90 inhibitor, 17AAG, protects the intestinal stem cell niche and inhibits graft versus host disease development.
2016
IF 7.932; International audience; Graft versus host disease (GvHD), which is the primary complication of allogeneic bone marrow transplantation, can alter the intestinal barrier targeted by activated donor T-cells. Chemical inhibition of the stress protein HSP90 was demonstrated in vitro to inhibit T-cell activation and to modulate endoplasmic reticulum (ER) stress to which intestinal cells are highly susceptible. Since the HSP90 inhibitor 17-allylamino-demethoxygeldanamycin (17AAG) is developed in clinics, we explored here its ability to control intestinal acute GvHD in vivo in two mouse GvHD models (C57BL/6 -> BALB/c and FVB/N -> Lgr5-eGFP), ex vivo in intestine organoids and in vitro in …
The Ontogeny of Monocyte Subsets
2019
Classical and non-classical monocytes, and the macrophages and monocyte-derived dendritic cells they produce, play key roles in host defense against pathogens, immune regulation, tissue repair and many other processes throughout the body. Recent studies have revealed previously unappreciated heterogeneity among monocytes that may explain this functional diversity, but our understanding of mechanisms controlling the functional programming of distinct monocyte subsets remains incomplete. Resolving monocyte heterogeneity and understanding how their functional identity is determined holds great promise for therapeutic immune modulation. In this review, we examine how monocyte origins and develo…
2019
Background/aims Skeletal muscle injuries are the most common type of injury occurring in sports, and investigating skeletal muscle regeneration as well as understanding the related processes is an important aspect of the sports medicine field. The process of regeneration appears to be complex and precisely orchestrated, involving fibro-adipogenic progenitors (FAPs) which are a muscle-resident stem cell population that appears to play a major role in abnormal development of fibrotic tissue or intermuscular adipose tissue (IMAT). Our present study aims to investigate whether muscle resting or endurance exercise following muscle injury may change the behavior of FAPs and subsequently impact th…
PRR signaling during in vitro macrophage differentiation from progenitors modulates their subsequent response to inflammatory stimuli.
2017
Toll-like receptor (TLR) agonists drive hematopoietic stem and progenitor cells (HSPCs) to differentiate along the myeloid lineage in vitro and also in vivo following infection. In this study, we used an in vitro model of HSPC differentiation to investigate the functional consequences (cytokine production) that exposing HSPCs to various pathogen-associated molecular patterns (PAMPs) and Candida albicans cells have on the subsequently derived macrophages. Mouse HSPCs (Lin- cells) were cultured with GM-CSF to induce macrophage differentiation in the presence or absence of the following pattern recognition receptor (PRR) agonists: Pam3CSK4 (TLR2 ligand), LPS (TLR4 ligand), depleted zymosan (wh…
Leukemia-associated activating mutation of Flt3 expands dendritic cells and alters T cell responses
2016
Lau et al. show that the FLT3-ITD mutation directly affects dendritic cell development in preleukemic mice, indirectly modulating T cell homeostasis and supporting the expansion of regulatory T cells.