Search results for "Cellular differentiation"
showing 10 items of 482 documents
Colony-stimulating factor-1-induced oscillations in phosphatidylinositol-3 kinase/AKT are required for caspase activation in monocytes undergoing dif…
2009
Abstract The differentiation of human peripheral blood monocytes into resident macrophages is driven by colony-stimulating factor-1 (CSF-1), which upon interaction with CSF-1 receptor (CSF-1R) induces within minutes the phosphorylation of its cytoplasmic tyrosine residues and the activation of multiple signaling complexes. Caspase-8 and -3 are activated at day 2 to 3 and contribute to macrophage differentiation, for example, through cleavage of nucleophosmin. Here, we show that the phosphatidylinositol-3 kinase and the downstream serine/threonine kinase AKT connect CSF-1R activation to caspase-8 cleavage. Most importantly, we demonstrate that successive waves of AKT activation with increasi…
Fine-tuning nucleophosmin in macrophage differentiation and activation
2011
Abstract M-CSF–driven differentiation of peripheral blood monocytes is one of the sources of tissue macrophages. In humans and mice, the differentiation process involves the activation of caspases that cleave a limited number of proteins. One of these proteins is nucleophosmin (NPM1), a multifunctional and ubiquitous protein. Here, we show that caspases activated in monocytes exposed to M-CSF cleave NPM1 at D213 to generate a 30-kDa N-terminal fragment. The protein is further cleaved into a 20-kDa fragment, which involves cathepsin B. NPM1 fragments contribute to the limited motility, migration, and phagocytosis capabilities of resting macrophages. Their activation with lipopolysaccharides …
Alpha-defensins secreted by dysplastic granulocytes inhibit the differentiation of monocytes in chronic myelomonocytic leukemia.
2010
Abstract Chronic myelomonocytic leukemia (CMML) is a clonal hematopoietic disorder that occurs in elderly patients. One of the main diagnostic criteria is the accumulation of heterogeneous monocytes in the peripheral blood. We further explored this cellular heterogeneity and observed that part of the leukemic clone in the peripheral blood was made of immature dysplastic granulocytes with a CD14−/CD24+ phenotype. The proteome profile of these cells is dramatically distinct from that of CD14+/CD24− monocytes from CMML patients or healthy donors. More specifically, CD14−/CD24+ CMML cells synthesize and secrete large amounts of alpha-defensin 1-3 (HNP1-3). Recombinant HNPs inhibit macrophage co…
Extra collagen overlay prolongs the differentiated phenotype in sandwich-cultured rat hepatocytes
2018
INTRODUCTION: Sandwich-cultured rat hepatocytes (SCRH) have become an invaluable in vitro model to study hepatic drug disposition. SCRH are maintained between two layers of extracellular matrix. In this configuration, culture periods of 4days are typically applicable. The aim of the present study was to modify conventional SCRH by applying an additional collagen overlay to prolong the hepatic phenotype in SCRH and thus to extend the applicability of the model. METHODS: The cultures receiving an extra top layer ('SCRH-plus' cultures) were compared with the conventional SCRH by testing the morphology, cell functionality, metabolic capacity and Mrp2-activity. RESULTS: In the SCRH-plus cultures…
Mesenchymal stem cells derived from inflamed dental pulpal and gingival tissue: a potential application for bone formation
2017
Background Chronic periodontal disease is an infectious disease consisting of prolonged inflammation of the supporting tooth tissue and resulting in bone loss. Guided bone regeneration procedures have become common and safe treatments in dentistry, and in this context dental stem cells would represent the ideal solution as autologous cells. In this study, we verified the ability of dental pulp mesenchymal stem cells (DPSCs) and gingival mesenchymal stem cells (GMSCs) harvested from periodontally affected teeth to produce new mineralized bone tissue in vitro, and compared this to cells from healthy teeth. Methods To characterize DPSCs and GMSCs, we assessed colony-forming assay, immunophenot…
Activated Thyroid Hormone Promotes Differentiation and Chemotherapeutic Sensitization of Colorectal Cancer Stem Cells by Regulating Wnt and BMP4 Sign…
2016
Abstract Thyroid hormone is a pleiotropic factor that controls many cellular processes in multiple cell types such as cancer stem cells (CSC). Thyroid hormone concentrations in the blood are stable, but the action of the deiodinases (D2–D3) provides cell-specific regulation of thyroid hormone activity. Deregulation of deiodinase function and thyroid hormone status has been implicated in tumorigenesis. Therefore, we investigated the role of thyroid hormone metabolism and signaling in colorectal CSCs (CR-CSC), where deiodinases control cell division and chemosensitivity. We found that increased intracellular thyroid hormone concentration through D3 depletion induced cell differentiation and s…
Transcription intermediary factor 1γ is a tumor suppressor in mouse and human chronic myelomonocytic leukemia.
2011
Transcription intermediary factor 1γ (TIF1γ) was suggested to play a role in erythropoiesis. However, how TIF1γ regulates the development of different blood cell lineages and whether TIF1γ is involved in human hematological malignancies remain to be determined. Here we have shown that TIF1γ was a tumor suppressor in mouse and human chronic myelomonocytic leukemia (CMML). Loss of Tif1g in mouse HSCs favored the expansion of the granulo-monocytic progenitor compartment. Furthermore, Tif1g deletion induced the age-dependent appearance of a cell-autonomous myeloproliferative disorder in mice that recapitulated essential characteristics of human CMML. TIF1γ was almost undetectable in leukemic ce…
Conserved role of Ras-GEFs in promoting aging: from yeast to mice
2011
RasGRF1 is a Ras-guanine nucleotide exchange factor implicated in a variety of physiological processes including learning and memory and glucose homeostasis. To determine the role of RASGRF1 in aging, lifespan and metabolic parameters were analyzed in aged RasGrf1(-/-) mice. We observed that mice deficient for RasGrf1(-/-) display an increase in average and most importantly, in maximal lifespan (20% higher than controls). This was not due to the role of Ras in cancer because tumor-free survival was also enhanced in these animals. Aged RasGrf1(-/-) displayed better motor coordination than control mice. Protection against oxidative stress was similarly preserved in old RasGrf1(-/-). IGF-I lev…
Effects of sodium butyrate on DNA content, glutathione S-transferase activities, cell morphology and growth characteristics of rat liver nonparenchym…
1993
The effects of sodium butyrate, which has been shown to act as a differentiation promoting agent in several different tumor cell lines, were studied in a rat liver nonparenchymal epithelial cell line. Exposure of these cells to 3.75 mM butyrate resulted in an inhibition of cell proliferation and, at the same time, an increase in cell diameter (2- to 6-fold) and size of the nuclei (approximately 2-fold) after 3 days in culture. Binucleated cells arose, comprising approximately 12% of the cells investigated, and the number of cells with an abnormal set of chromosomes was increased. Intercellular communication, measured by dye transfer of Lucifer Yellow, was unchanged. From the various xenobio…
RORC1 Regulates Tumor-Promoting "Emergency" Granulo-Monocytopoiesis
2015
Cancer-driven granulo-monocytopoiesis stimulates expansion of tumor promoting myeloid populations, mostly myeloid-derived suppressor cells (MDSCs) and tumor-associated macrophages (TAMs). We identified subsets of MDSCs and TAMs based on the expression of retinoic-acid-related orphan receptor (RORC1/RORγ) in human and mouse tumor bearers. RORC1 orchestrates myelopoiesis by suppressing negative (Socs3 and Bcl3) and promoting positive (C/EBPβ) regulators of granulopoiesis, as well as the key transcriptional mediators of myeloid progenitor commitment and differentiation to the monocytic/macrophage lineage (IRF8 and PU.1). RORC1 supported tumor-promoting innate immunity by protecting MDSCs from …