Hematopoietic stem cells (HSCs) are located in the bone marrow in a specific microenvironment referred as the hematopoietic stem cell niche, where HSCs interact with a variety of stromal cells. Though several components of the stem cell niche have been identified, the regulatory mechanisms through which such components regulate the stem cell fate are still unknown. In order to address this issue, we investigated how osteoblasts (OBs) can affect the molecular and functional phenotype of HSCs and vice versa. Our data showed that CD34+ cells cultured with OBs give rise to higher total cell numbers, produce more CFU and maintain a higher percentage of CD34+CD38- cells compared to control culture. Moreover, clonogenic assay and long-term culture results showed that OBs enhance HSC differentiation towards the mono/macrophage lineage at the expense of the granulocytic and erythroid ones. Finally, GEP analysis allowed us to identify several cytokine-receptor networks, such as WNT pathway, and transcription factors, as TWIST1 and FOXC1, that could be activated by co-culture with OBs and could be responsible for the biological effects reported above.
Co-culture of hematopoietic stem/progenitor cells with human osteblasts favours mono/macrophage differentiation at the expense of the erythroid lineage.
Specimen part, Time
View SamplesThe BM-derived CD45+/Sca1+ cells are haematopoietic stem/progenitor cells that have the ability to circulate and migrate and engraft to the muscle tissue, and therefore they are of particular interest. Notably, these cells retain their haematopoietic potential, as revealed both by in vitro and in vivo assays; but they also acquire myogenic potential, as shown by their ability to participate in muscle regeneration. Whether, this latter remarkable ability is the result of the reprogramming of the BM-CD45+/Sca1+ cells and the activation of a myogenic molecular program within these cells, remains controversial. This study aims to clarify this aspect of the process, investigating the role of the muscle microenviroment and key myogenic transcription factors.
Bone marrow-derived hematopoietic cells undergo myogenic differentiation following a Pax-7 independent pathway.
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View SamplesThe 6-hydroxydopamine (6OHDA) rat model of parkinsonism is among the first, and most commonly used, animal models of Parkinsons disease. It provides insight into the compensatory changes that occur in the brain after dopamine (DA) neuron degeneration. In order to better define the consequences of substantia nigra DA neuron loss on the neural and glial populations during and following nigrostriatal degeneration, tissue was collected and evaluated from the substantia nigra of 6OHDA or vehicle treated, or nave rats at 1, 2, 4, 6 & 16 weeks.
The longitudinal transcriptomic response of the substantia nigra to intrastriatal 6-hydroxydopamine reveals significant upregulation of regeneration-associated genes.
Sex, Specimen part
View SamplesExtracellular nucleotides are potent signaling molecules mediating cell-specific biological functions. We previously demonstrated that adenosine 5'-triphosphate (ATP) inhibits the proliferation while stimulating the migration, in vitro and in vivo, of human bone marrow-derived mesenchymal stem cells (BM-hMSC). Here, we investigated the effects of ATP on BM-hMSC differentiation capacity.
Extracellular purines promote the differentiation of human bone marrow-derived mesenchymal stem cells to the osteogenic and adipogenic lineages.
Specimen part, Treatment, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Role of CD34 antigen in myeloid differentiation of human hematopoietic progenitor cells.
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View SamplesIn order to investigate the role of CD34 antigen in haematopoietic commitment, we overexpressed the human CD34 cDNA in human CD34+ cells by retroviral gene transfer.
Role of CD34 antigen in myeloid differentiation of human hematopoietic progenitor cells.
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View SamplesIn order to investigate the role of CD34 antigen in haematopoietic commitment, we silenced the CD34 gene expression in CD34+ stem/progenitor cells using a siRNA approach.
Role of CD34 antigen in myeloid differentiation of human hematopoietic progenitor cells.
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View SamplesThe c-Myb transcription factor is highly expressed in immature hematopoietic cells and down-regulated during differentiation. To define the role of c-Myb in human hematopoietic lineage commitment, we studied the effects of its silencing during the commitment of human CD34+ Hematopoietic stem/progenitor cells. In CD34+ cells c-Myb silencing determined a cell cycle arrest in G0/G1 phase which strongly decreased the clonogenic efficiency, togheter with a reduction of erythroid colonies coupled with an increase of the macrophage and megakaryocyte ones. Moreover, morphological and flow cytometry data supported the preferential macrophage and megakaryocyte differentiation of c-Myb-silenced CD34+ cells. Taken together our data indicate that c-Myb is essential for the commitment along the erythroid and granulocyte lineages but not for the macrophage and megakaryocyte differentiation. Gene expression profiling of c-Myb-silenced CD34+ cells identified some potential c-Myb targets which can account for these effects, to study by Chromatin Immunoprecipitation and Luciferase Reporter Assay.
c-myb supports erythropoiesis through the transactivation of KLF1 and LMO2 expression.
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View SamplesThe c-Myb transcription factor is highly expressed in immature hematopoietic cells and down-regulated during differentiation. To define the role of c-Myb during the terminal differentiation of hematopoietic precursors, we studied the effects of its silencing in human primary CD14-myeloblasts, which maintain a granulo-monocyte differentiation bipotentiality. c-Myb-silenced myeloblasts were blocked in the G1 phase of the cell cycle at 24 hours post-nucleofection and subsequently were forced towards macrophage differentiation, as demonstrated by immunophenotypic and morphological analysis. Indeed, c-Myb-silenced CD14- cells differentiate to macrophage even after the treatment with ATRA 10-6 M, demonstrating that the c-Myb knockdown strongly impairs the ability of myeloblasts to differentiate to granulocytes. Gene expression profiling of c-Myb-silenced CD14- cells identified some potential c-Myb targets that can account for these effects.
c-myb supports erythropoiesis through the transactivation of KLF1 and LMO2 expression.
Specimen part, Time
View SamplesThe JAK2V617F mutation has been reported in about 40-60% of Essential Thrombocythemia (ET) patients. However, little is known about specific molecular abnormalities of the hematopoietic stem cell compartment of ET according to JAK2 mutation. Therefore, we compared the gene expression profiles of bone marrow (BM) CD34+ cells from 16 patients with and without the JAK2V617F mutation to identify differentially expressed genes.
Molecular profile of CD34+ stem/progenitor cells according to JAK2V617F mutation status in essential thrombocythemia.
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