Search results for "Haematopoiesi"
showing 10 items of 183 documents
CD146+ bone marrow osteoprogenitors increase in the advanced stages of primary myelofibrosis
2008
Abstract CD146+ bone marrow stromal cells have been recently recognized as clonogenic osteoprogenitors able to organize a complete hematopoietic microenvironment. In this study we used immunohistochemical analysis to investigate the contribution of CD146+ bone marrow osteoprogenitors to the stromal remodeling occurring in the different stages of primary myelofibrosis. We found that CD146+ cells sited at the abluminal side of the bone marrow vessels and branching among hematopoietic cells significantly increased in the advanced stages of primary myelofibrosis (p<0.001), paralleling the extent of fibrosis (r=0.916, p<0.0001) and the microvascular density (r=0.883, p<0.0001). Coherently with a…
A novel role of the CX3CR1/CX3CL1 system in the cross-talk between chronic lymphocytic leukemia cells and tumor microenvironment
2011
Several chemokines/chemokine receptors such as CCR7, CXCR4 and CXCR5 attract chronic lymphocytic leukemia (CLL) cells to specific microenvironments. Here we have investigated whether the CX(3)CR1/CX(3)CL1 axis is involved in the interaction of CLL with their microenvironment. CLL cells from 52 patients expressed surface CX(3)CR1 and CX(3)CL1 and released constitutively soluble CX(3)CL1. One third of these were attracted in vitro by soluble CX(3)CL1. CX(3)CL1-induced phosphorylation of PI3K, Erk1/2, p38, Akt and Src was involved in induction of CLL chemotaxis. Leukemic B cells upregulated CXCR4 upon incubation with CX(3)CL1 and this was paralleled by increased chemotaxis to CXCL12. Akt phosp…
Competition between clonal plasma cells and normal cells for potentially overlapping bone marrow niches is associated with a progressively altered ce…
2011
Disappearance of normal bone marrow (BM) plasma cells (PC) predicts malignant transformation of monoclonal gammopathy of undetermined significance (MGUS) and smoldering myeloma (SMM) into symptomatic multiple myeloma (MM). The homing, behavior and survival of normal PC, but also CD34 hematopoietic stem cells (HSC), B-cell precursors, and clonal PC largely depends on their interaction with stromal cell-derived factor-1 (SDF-1) expressing, potentially overlapping BM stromal cell niches. Here, we investigate the distribution, phenotypic characteristics and competitive migration capacity of these cell populations in patients with MGUS, SMM and MM vs healthy adults (HA) aged 60 years. Our result…
Improved multilineage response of hematopoiesis in patients with myelodysplastic syndromes to a combination therapy with all-trans-retinoic acid, gra…
1996
Differentiation induction therapy is being tested in myelodysplastic syndromes to ameliorate maturation defects and to restore normal hematopoietic function. To this end, 17 patients (eight with refractory anemia, two with refractory anemia and ring sideroblasts, and seven with refractory anemia and excess of blast cells) were treated with a combination of all-trans-retinoic acid (ATRA), granulocyte colony-stimulating factor (G-CSF), erythropoietin (EPO), and alpha-tocopherol for durations of 8-16 weeks. Absolute neutrophil counts increased in all patients; platelet counts increased in five patients with discontinuation of transfusion needs in two of four transfusion-dependent patients. Sti…
Hemopoietic and angiogenetic progenitors in healthy athletes: different responses to endurance and maximal exercise
2010
J Appl Physiol. 2010 Jul;109(1):60-7. Epub 2010 May 6. Hemopoietic and angiogenetic progenitors in healthy athletes: different responses to endurance and maximal exercise. Bonsignore MR, Morici G, Riccioni R, Huertas A, Petrucci E, Veca M, Mariani G, Bonanno A, Chimenti L, Gioia M, Palange P, Testa U. SourceBiomedical Department, Internal and Specialistic Medicine (DIBIMIS), Section of Pneumology, University of Palermo, Via Trabucco, 180, 90146 Palermo, Italy. marisa@ibim.cnr.it Abstract The effects of endurance or maximal exercise on mobilization of bone marrow-derived hemopoietic and angiogenetic progenitors in healthy subjects are poorly defined. In 10 healthy amateur runners, we collect…
Regulation of immunomodulatory functions by granulocyte-macrophage colony-stimulating factor and granulocyte colony-stimulating factor in vivo
1996
The present study was designed to investigate in vivo immunomodulatory properties of hematopoietic growth factors. The influence on the activation of cytokine synthesis and on the expression of surface antigens associated with cellular activation of G-CSF or GM-CSF was investigated in cancer patients receiving these factors. One single dose of growth factor was administered to patients with bladder cancer (G-CSF group) or small cell lung cancer (GM-CSF group) before chemotherapy. After cytoreductive chemotherapy patients received supportive therapy with G-CSF or GM-CSF. Peripheral blood mononuclear cells and plasma samples were obtained for flow cytometry, Northern blot analysis, and assess…
Tif1γ regulates the TGF-β1 receptor and promotes physiological aging of hematopoietic stem cells.
2014
The hematopoietic system declines with age. Myeloid-biased differentiation and increased incidence of myeloid malignancies feature aging of hematopoietic stem cells (HSCs), but the mechanisms involved remain uncertain. Here, we report that 4-mo-old mice deleted for transcription intermediary factor 1γ (Tif1γ) in HSCs developed an accelerated aging phenotype. To reinforce this result, we also show that Tif1γ is down-regulated in HSCs during aging in 20-mo-old wild-type mice. We established that Tif1γ controls TGF-β1 receptor (Tgfbr1) turnover. Compared with young HSCs, Tif1γ(-/-) and old HSCs are more sensitive to TGF-β signaling. Importantly, we identified two populations of HSCs specifical…
The erythropoietin and regenerative medicine: a lesson from fish
2009
Background Erythropoietin (EPO), the main haematopoietic growth factor for the proliferation and differentiation of erythroid progenitor cells, is also known for its angiogenic and regenerative properties. Materials and methods In this study, we aimed to test the regenerative effects of EPO administration in an experimental model of Sea bass (Dicentrarchus labrax) subjected to amputation of the caudal fin. Results Erythropoietin-treated fishes (3000 UI of human recombinant EPO-alpha immediately after cutting and after 15 days) showed an increased growth rate of their fins compared with those untreated (ANOVA variance: P :0 AE01 vs. P :0 AE04). By analysing fin length at established times (1…
A Neuroprotective Function for the Hematopoietic Protein Granulocyte-Macrophage Colony Stimulating Factor (GM-CSF)
2007
Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a hematopoietic cytokine responsible for the proliferation, differentiation, and maturation of cells of the myeloid lineage, which was cloned more than 20 years ago. Here we uncovered a novel function of GM-CSF in the central nervous system (CNS). We identified the GM-CSF α-receptor as an upregulated gene in a screen for ischemia-induced genes in the cortex. This receptor is broadly expressed on neurons throughout the brain together with its ligand and induced by ischemic insults. In primary cortical neurons and human neuroblastoma cells, GM-CSF counteracts programmed cell death and induces BCL-2 and BCL-Xl expression in a dose- a…
Hematopoietic Stem Cells Reversibly Switch from Dormancy to Self-Renewal during Homeostasis and Repair
2008
Bone marrow hematopoietic stem cells (HSCs) are crucial to maintain lifelong production of all blood cells. Although HSCs divide infrequently, it is thought that the entire HSC pool turns over every few weeks, suggesting that HSCs regularly enter and exit cell cycle. Here, we combine flow cytometry with label-retaining assays (BrdU and histone H2B-GFP) to identify a population of dormant mouse HSCs (d-HSCs) within the lin(-)Sca1(+)cKit(+)CD150(+)CD48(-)CD34(-) population. Computational modeling suggests that d-HSCs divide about every 145 days, or five times per lifetime. d-HSCs harbor the vast majority of multilineage long-term self-renewal activity. While they form a silent reservoir of th…