Navegando por Palavras-chave "Hematopoiesis"
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- ItemSomente MetadadadosAvaliação dos mecanismos intracelulares da diferenciação mielóide por receptores P2(Universidade Federal de São Paulo (UNIFESP), 2019-06-27) Araujo Junior, Roberto Theodoro De [UNIFESP]; Gamero, Edgar Julian Paredes [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Hematopoiesis is the process by which the organism forms all the bloodlines that occurs throughout the life of the individual. The capacity for self-renewal, quiescence and differentiation in multiple steps presented by hematopoietic stem cells (HTCs) are essential characteristics for the maintenance of homeostasis of hematopoietic tissue. In addition to cytokines, other signaling agents such as ATP, secreted by endothelial cells and osteoblasts, can modulate hematopoiesis by the activation of extracellular receptors. Several works have shown the capacity of ATP and analogues, in activating P2 receptors, and in modulating the activity of mature hematopoietic cells and in CTHs. Our group demonstrated that extracellular ATP promotes differentiation of HTCs through the increase of intracellular calcium promoted by P2 receptors. Although the modulation of hematopoiesis by ATP and analogs through the activation of P2 receptors has been observed, the receptor subtypes involved and the intracellular pathways that depend on these effects have not been fully elucidated. This work aims to elucidate the intracellular pathways related to the induction of myeloid differentiation promoted by P2 receptors. It was demonstrated in the present study that CTHs undergo differentiation through the activation of P2 receptors, ATP-treated HTCs increase Ki67 cell proliferation marker expression, thus indicating that these cells have lost the characteristic quiescence of HTCs. In addition, the Pi3K / AKT pathways were activated, and AKT was phosphorylated at both activation sites, thus demonstrating that both the PDK-1 enzyme and the mTOR protein complex are involved in signaling this process. CaMKII and PKC enzymes of the calcium dependent pathways were also activated, but without activation of CaMKIV. Among the pathways activated by P2Y receptors are those of PLCβ3 which, among other actions, is capable of inducing an increase in cytosolic calcium. Some transcription factors such as Stats 3 and 5 were also evaluated, both of which were activated by Janus kinase-independent pathways, as well as the best known Bcl-2 oncoprotein due to its participation in the apoptotic control process, but which has a role in the process of cell differentiation. Finally, the ERK was activated in a sustained manner for up to 24 hours, the process of activation of the ERK pathway is strongly linked to differentiation processes, and to corroborate this result a specific inhibitor for MEK was able to reverse the induced differentiation process by ATP. xviii These data together suggest that P2 receptors lead hematopoietic stem cells to differentiate themselves by signaling many pathways and that the role of MAPK ERK is of fundamental importance for this process.
- ItemAcesso aberto (Open Access)CD34-positive cells and their subpopulations characterized by flow cytometry analyses on the bone marrow of healthy allogenic donors(Associação Paulista de Medicina - APM, 2009-01-01) Carvalho, Jerusa Martins [UNIFESP]; Souza, Marlon Knabben de [UNIFESP]; Buccheri, Valéria; Rubens, Cláudia Viviane; Kerbauy, José [UNIFESP]; Oliveira, José Salvador Rodrigues de [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Universidade de São Paulo (USP); Fundação Maria Cecília Couto Vidigal Head of Laboratory of Cell Biology; Fundação Maria Cecília Couto Vidigal Biochemistry researcher in the Cell Biology LaboratoryCONTEXT AND OBJECTIVE: Counting and separating hematopoietic stem cells from different sources has importance for research and clinical assays. Our aims here were to characterize and quantify hematopoietic cell populations in marrow donors and to evaluate CD34 expression and relate this to engraftment. DESIGN AND SETTING: Cross-sectional study on hematopoietic stem cell assays, using flow cytometry on donor bone marrow samples, for allogenic transplantation patients at two hospitals in São Paulo. METHODS: Immunophenotyping of marrow cells was performed in accordance with positive findings of CD34FITC, CD117PE, CD38PE, CD7FITC, CD33PE, CD10FITC, CD19PE, CD14FITC, CD13PE, CD11cPE, CD15FITIC, CD22PE, CD61FITC and CD56PE monoclonal antibodies in CD45PerCP+ cells, searching for differentiation and maturation regions. CD34+ sorting cells were analyzed for CD38 and CD117. Rh-123 retention was done before and after sorting. Antigen expression and CD34+ cells were correlated with engraftment. RESULTS: In region R1, 0.1% to 2.8% of cells were CD34+/CD45+ and 1.1%, CD34+/CD45-. The main coexpressions of CD45+ cells were CD38, CD22, CD19 and CD56 in R2 and CD33, CD11c, CD14, CD15 and CD61 in R3 and R4. After sorting, 2.2x10(6) CD34+ cells were equivalent to 4.9% of total cells. Coexpression of CD34+/CD38+ and CD34+/CD117+ occurred in 94.9% and 82% of events, respectively. There was a positive relationship between CD34+ cells and engraftment. More than 80% of marrow cells expressed high Rh-123. CD34+ cell sorting showed that cells in regions of more differentiated lineages retained Rh-123 more intensively than in primitive lineage regions. CONCLUSION: We advocate that true stem cells are CD34+/CD45-/CD38-/low-Rh-123 accumulations.
- ItemAcesso aberto (Open Access)Chlorella vulgaris restores bone marrow cellularity and cytokine production in lead-exposed mice(Elsevier B.V., 2011-11-01) Queiroz, Mary L. S.; Rocha, Michelle C. da; Torello, Cristiane O.; Queiroz, Julia de Souza; Bincoletto, Claudia [UNIFESP]; Morgano, Marcelo A.; Romano, Miriam R.; Paredes-Gamero, Edgar Julian [UNIFESP]; Barbosa, Christiano Marcello Vaz [UNIFESP]; Calgarotto, Andrana K.; Universidade Estadual de Campinas (UNICAMP); Universidade Federal de São Paulo (UNIFESP); ITALChlorella vulgaris (CV) was examined for its modulating effects on the reduction induced by lead (Pb) on the numbers of marrow hematopoietic stem cells (HSCs) (c-Kit(+)Lin(-)), granulocyte-macrophage progenitors (Gr1(+)Mac1(+)) and total bone marrow cellularity. in mice gavage-treated daily with 50 mg/kg dose of CV for 10 days, concomitant to a continuous offering of 1300 ppm lead acetate in drinking water, the treatment with the algae recovered the significantly reduced numbers of these cell populations to control values. As CV may have a myelostimulating effect through the induction of cytokines, we evaluated its modulating effects on the production of IL-1 alpha, TNF-alpha, IFN-gamma, IL-10 and IL-6. Our results demonstrated that lead significantly impairs the production of IFN-gamma, IL-1 alpha and TNF-alpha and increases the production of IL-10 and IL-6 and that these effects are successfully modulated by the CV treatment. the activity of NK cells, reduced in Pb-exposed animals, was raised to levels higher than those of controls in the exposed group treated with CV. Treatment with the algae also stimulated the production of IFN-gamma, IL-1 alpha, TNF-alpha and NK cells activity in normal mice. in addition, zinc bone concentrations, reduced in lead-exposed mice, were partially, but significantly, reversed by the treatment with CV. (C) 2011 Elsevier B.V. All rights reserved.
- ItemAcesso aberto (Open Access)Chlorella vulgaris treatment ameliorates the suppressive effects of single and repeated stressors on hematopoiesis(Elsevier B.V., 2013-03-01) Queiroz, Julia de Souza; Barbosa, Christiano Marcello Vaz [UNIFESP]; Rocha, Michelle C. da; Bincoletto, Claudia [UNIFESP]; Paredes-Gamero, Edgar Julian [UNIFESP]; Souza Queiroz, Mary Luci de Souza; Palermo Neto, João; Universidade Estadual de Campinas (UNICAMP); Universidade Federal de São Paulo (UNIFESP); Universidade de São Paulo (USP)The reports regarding the mutual influence between the central nervous system and the immune system constitute a vast and somewhat controversial body of literature. Stress is known to disturb homeostasis, impairing immunological functions. in this study, we investigated the hematopoietic response of Chlorella vulgaris (CV)-treated mice exposed to single (SST) and repeated stress (RST). We observed a reduction in the numbers of hematopoietic progenitors (HP) in the bone marrow and long-term bone marrow cultures (LTBMC) using flow cytometry and a coinciding decrease in the number of granulocyte-macrophage colonies (CFU-GM) after treatment with both stressors, but SST caused a more profound suppression. We observed a proportional increase in the colony-stimulating activity (CSA) of the serum of animals subjected to SST or RST. in the bone marrow, SST and RST induced a decrease in both mature myeloid and lymphoid populations but did not affect pluripotent hematopoietic progenitors (Lin(-)Sca-1(+)c-kit(+), LSK), and again, a more profound suppression was observed after SST. We further quantified the levels of interleukin-1 alpha (IL-1 alpha) and interleukin-6 (IL-6) and the number of myeloid cells in LTBMC. Both SST and RST reduced the levels of these cytokines to similar degrees. the myeloid population was also reduced in LTBMC, and SST induced a more intense suppression. Importantly, CV treatment prevented the changes produced by SST and RST in all of the parameters evaluated. Together, our results suggest that CV treatment is an effective tool for the prophylaxis of myelosuppression caused by single or repeated stressors. (c) 2012 Elsevier Inc. All rights reserved.
- ItemEmbargoEfeito do tratamento materno com dexametasona em fígado fetal de ratos: o papel de macrófagos no metabolismo do ferro e maturação de eritroblastos(Universidade Federal de São Paulo (UNIFESP), 2010-11-24) Neves, Flavia Macedo de Oliveira [UNIFESP]; Miraglia, Sandra Maria [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Macrophages (MƒÖs) have important roles during development as a phagocytosis of apoptotic cells, secretion of growth factors and cytokines as well as angiogenesis induction. In the fetal liver (FL), erythroblasts at various stages of differentiation associate with central MƒÖs to form erythroblastic islands (EI). During erythropoiesis, central MƒÖs regulate the proliferation and differentiation of erythroblasts by supplying of growth factors and nutrients as iron to heme synthesis. In addition, central MƒÖs have been shown to produce erythropoietin, the principal factor in the regulation of erythropoiesis. In addition, these cells recognize and uptake extruded erythroblast nuclei. Macrophage differentiation and erythropoiesis can be affected by glucocorticoids (GCs). During the pregnancy, GCs are frequently used to accelerate fetal lung maturation and other organs in the preterm delivery. Thus, in these work we examined changes in the central MƒÖs and erythroblasts of EI after maternal treatment with synthetic GCs. To investigate this, female Wistar rats were mated and treated between 13 to 16 dpc with dexamethasone 21-phosphate (100 ƒÝg/Kg BW/day) or vehicle (control - 0.9% NaCl). At 17 dpc, pregnant rats were euthanized and fetuses were collected to liver isolation. Fetal livers (FL) were processed to light and transmission electron microscopy. Sections (2 £gm) of FL embedded in glycol methacrylate were stained with PAS to determine the erythroid cell (proerythroblasts, basophilic, polychromatophilic and orthochromatic erythroblasts) frequencies. Total cell number from each EI was significant reduced in treated animals. To iron detection, tissue was embedded in paraffin, cut at 5 £gm and stained by Perls+DAB method. Iron accumulation was more evident in MƒÖs from FL of treated fetuses. To confirm this, areas staining positive for iron were converted to pixels and analyzed by software. Ultrastructural observations also showed electron dense granular material similar at iron deposits in cells from IE from treated fetuses. The same was not observed in the control. Iron deposits in central MƒÖs and erythroblasts were confirmed by staining sections with bismuth subnitrate. To test if GCs may induce changes in the cellular iron storage we used rat peritoneal macrophages treated with dexamethasone (10 nM) for 24 h. These cells were incubated with FeCl3 (100 £gM) for 4 h and stained by Prussian blue method. Dexamethasone treated-MƒÖs exhibited greatest amount of intracellular iron than untreated cells confirmed by blue granules quantification. Taken together, these results suggest that dexamethasone can interfere in iron uptake and/or release by macrophages and in the proliferation of erythroblasts affecting the fetal erythropoiesis in rats.
- ItemSomente MetadadadosHematopoietic defects in response to reduced Arhgap21(Elsevier Science Bv, 2018) Xavier-Ferrucio, Juliana; Ricon, Lauremilia; Vieira, Karla; Longhini, Ana Leda; Lazarini, Mariana [UNIFESP]; Bigarella, Carolina Louzao; Franchi, Gilberto, Jr.; Krause, Diane S.; Saad, Sara T. O.Arhgap21 is a member of the Rho GTPase activating protein (RhoGAP) family, which function as negative regulators of Rho GTPases. Arhgap21 has been implicated in adhesion and migration of cancer cells. However, the role of Arhgap21 has never been investigated in hematopoietic cells. Herein, we evaluated functional aspects of hematopoietic stem and progenitor cells (HSPC) using a haploinsufficient (Arhgap21(+/-)) mouse. Our results show that Arhgap21(+/-) mice have an increased frequency of phenotypic HSC, impaired ability to form progenitor colonies in vitro and decreased hematopoietic engraftment in vivo, along with a decrease in LSK cell frequency during serial bone marrow transplantation. Arhgap21(+/-) hematopoietic progenitor cells have impaired adhesion and enhanced mobilization of immature LSK and myeloid progenitors. Arhgap21(+/-) mice also exhibit reduced erythroid commitment and differentiation, which was recapitulated in human primary cells, in which knockdown of ARHGAP21 in CMP and MEP resulted in decreased erythroid commitment. Finally, we observed enhanced RhoC activity in the bone marrow cells of Arhgap21(+/-) mice, indicating that Arhgap21 functions in hematopoiesis may be at least partially mediated by RhoC inactivation. (c) 2017 The Authors. Published by Elsevier B.V.
- ItemAcesso aberto (Open Access)High-fat diet increases STAT-3 and c-Myc expression and induces VEGF production in hone marrow mesenchymal stem cells in a rat model(Natl Inst Science Communication-Niscair, 2017) do Carmo, Luciana Simao; de Oliveira, Dalila Cunha; Cortez, Mayara; Nogueira-Pedro, Amanda [UNIFESP]; Paredes-Gamero, Edgar Julian [UNIFESP]; Borelli, Primavera; Rogero, Marcelo Macedo; Fock, Ricardo AmbrosioExcessive intake of a high-fat diet (HFD) results in overweight, obesity and the development of insulin resistance, adipose tissue macrophage infiltration and significant increases in inflammatory biomarkers. Bone marrow mesenchymal stem cells (MSCs) are directly involved in hematopoiesis and angiogenesis, and are currently receiving considerable attention due to their remarkable applications to cell therapy. In obese people, hematopoiesis and angiogenesis can be affected as a result of the unbalanced production of several kinds of mediators, such as VEGF. VEGF production is regulated by transcription factors such as Stat-3, which can also activate other transcription factor regulators such as c-Myc, which is closely correlated to cell proliferation. Two-month-old male Wistar rats were fed an HFD and bone marrow MSCs were isolated. The cell cycle, Stat-3 and c-Myc expression, and VEGF production were evaluated. HFD animals showed greater adipose tissue mass as well as higher blood cholesterol, leptin, and C-reactive protein levels. MSCs from the HFD group showed a higher percentage of cells in the S/G2/M phase, increased production of VEGF and higher expression of c-Myc and Stat-3. These data led us to infer that HFD induces alterations in bone marrow MSCs, which could modify their modulatory capability and affect their use in cell therapies.
- ItemAcesso aberto (Open Access)Matriz extracelular e enzimas degradatórias na hematopoese e doenças onco-hematológicas(Associação Brasileira de Hematologia e Hemoterapia e Terapia Celular, 2008-10-01) Dreyfuss, Juliana Luporini [UNIFESP]; Oliveira, José Salvador Rodrigues de [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)The extracellular matrix (ECM) is a complex structure composed of collagens, proteoglycans, glycosaminoglycans and adhesive glycoproteins. Interactions between the cells and the ECM are crucial to determine cell behavior, such as growth, death, differentiation and motility. Hematopoiesis is the system responsible for the production of blood cells. The control of proliferation and differentiation of these cells is attained through the interaction of the cells with the bone marrow microenvironment. The adhesion of hematopoietic progenitors to ECM molecules and the integrin activation are modulated by a variety of cytokines and growth factors, and this modulation seems to be the mechanism of regulation that influences proliferation of hematopoietic cells, transendothelial/transstromal migration and homing. Both in the migration and homing process, and in tumoral invasion the cells undergo the following steps: 1 - Degradation of the ECM by enzymes, including metalloproteinase, collagenase, plasmin, cathepsin, glycosidase and heparanase, secreted by the cells; 2 - Cell migration through the region previously degraded by enzymes; and 3 - Cell adhesion to specific receptors located on the cellular surface, that generally interact with ECM components. In onco-hematologic diseases, the interaction of neoplastic cells with the extracellular matrix also influences aggressiveness and prognosis of the disease.