The 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 SamplesHematopoietic 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 SamplesHistone deacetylase (HDAC) inhibitors are widely utilized in hematopoietic malignance therapy; nevertheless, little is currently known concerning their effects on normal myelopoiesis. In order to investigate a putative interference of HDAC inhibitors in myeloid commitment of hematopoietic stem/progenitor cells (HSPCs) we treated CD34+ cells with valproic acid (VPA). Moreover, we investigate changes in gene expression induced by VPA treatment on HSPCs, by means of microarray analysis in VPA treated and untreated (CTR) CD34+ cells.
Valproic acid triggers erythro/megakaryocyte lineage decision through induction of GFI1B and MLLT3 expression.
Specimen part, Treatment
View SamplesAs recently reported by our group, we performed miRNA and gene expression profiling of CD34+ hematopoietic stem/progenitor cells (HSPCs) isolated from 42 PMF patient samples compared with 31 healthy controls. Integrative analysis of these profiles by means of Ingenuity Pathway Analysis (IPA) allowed the identification of several aberrantly regulated miRNA-mRNA target pairs organized in interaction networks. In particular, our results highlighted the up-regulation of miR-494-3p in CD34+ cells from PMF patients (Norfo R et al, Blood, 2014). Interestingly, among the most upregulated miRNAs, miR-494-3p emerges as being associated to the highest number of downregulated target mRNAs. In order to understand the biological role of miR-494-3p during the hematopoietic commitment and differentiation, we overexpressed this miRNA in cord blood (CB) derived-CD34+ cells. Cells were electroporated with either miR-494-3p miRNA mimic (mimic miR-494) or a negative control mimic (mimic Neg CTR). qRT-PCR confirmed miR-494-3p overexpression 24h and 4 days after transfection (RQ SEM, 512.60 137.37, p<.01, and 20.63 3.03, p<.01, respectively).
miR-494-3p overexpression promotes megakaryocytopoiesis in primary myelofibrosis hematopoietic stem/progenitor cells by targeting SOCS6.
Specimen part, Treatment
View SamplesBackground. Differential gene expression in adipose tissue during diet-induced weight loss followed by a weight stability period is not well characterized. Markers of these processes may provide a deeper understanding of the underlying mechanisms. Objective. To identify differentially expressed genes in human adipose tissue during weight loss and weight maintenance after weight loss. Design. RNA from subcutaneous abdominal adipose tissue from nine obese subjects was obtained and analyzed at baseline, after weight reduction on a low calorie diet (LCD), and after a period of group therapy in order to maintain weight stability. Results. Subjects lost 18.8 + 5.4% of their body weight during the LCD and maintained this weight during group therapy. Insulin sensitivity (HOMA) improved after weight loss with no further improvement during weight maintenance. Cyclin-dependent kinase inhibitor 2B (CDKN2B) and JAZF zinc finger 1 (JAZF1), associated with type 2 diabetes, were downregulated. We could also confirm the downregulation of candidates for obesity and related traits, such as tenomodulin (TNMD) and matrix metallopeptidase 9 (MMP9), with weight loss. The expression of other candidates, such as cell death-inducing DFFA-like effector A (CIDEA) and stearoyl-CoA desaturase (SCD) were upregulated during weight loss but returned to baseline levels during weight maintenance. Conclusion. Genes in the adipose tissue are differentially expressed during weight loss and weight maintenance after weight loss. Genes that show sustained regulation may be of potential interest as markers of the beneficial effects of weight loss whereas others seem to be primarily involved in the process of weight loss itself.
Differential gene expression in adipose tissue from obese human subjects during weight loss and weight maintenance.
Sex, Age
View SamplesThe pathogenic mechanisms of common kidney glomerular diseases, including the vast majority of cases of proteinuria, remain unknown.
Glomerular transcriptome changes associated with lipopolysaccharide-induced proteinuria.
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View SamplesAt least 30 types of retinal ganglion cell (RGC) send distinct messages through the optic nerve to the brain. Strategies for promoting regeneration of RGC axons following injury act on only some of these types. Here we tested the hypothesis that over-expressing developmentally important transcription factors in adult RGCs could reprogram them to a “youthful” growth-competent state and promote regeneration of other types. From a screen of transcription factors expressed by developing RGCs, we found one, Sox11, that induced substantial axon regeneration. Transcriptome profiling confirmed that Sox11 activates genes involved in cytoskeletal remodeling and axon growth. Remarkably, alpha-RGCs, which preferentially regenerate following treatments such as PTEN deletion, were killed by Sox 11. Thus, Sox 11 promotes regeneration of non-alpha RGCs, which are refractory to PTEN. We conclude that Sox11 can reprogram adult RGCs to a growth-competent state and that different growth-promoting interventions act on distinct neuronal types. Overall design: We compared transcriptomes of retinal ganglion cells between AAV-Control retinas, and retinas treated with AAV-Sox11 overexpression. We then performed optic nerve crush, and 3 days later purified RGCs using FACS. RGCs were marked with Thy1-PE-Cy7 antibody and with live/dead cell staining. We performed sample preparations in full triplicate, and in each replicate we always performed Control and Sox11 on the same day, in alternating order.
Sox11 Expression Promotes Regeneration of Some Retinal Ganglion Cell Types but Kills Others.
Specimen part, Subject
View SamplesAtopic dermatitis (AD) is a common inflammatory skin disease with underlying defects in epidermal function and immune responses. The goal of this study was to investigate differences in gene expression in lesional skin from patients with mild extrinsic or intrinsic AD compared to skin from healthy controls and from lesional psoriasis skin. The aim was to identify differentially expressed genes involved in skin barrier formation and inflammation, and to compare our results with those reported for patients with moderate and severe AD.
Distinct molecular signatures of mild extrinsic and intrinsic atopic dermatitis.
Specimen part, Disease
View SamplesExamine global gene expression patterns in control and 35S:PAP1 Arabidopsis plants upon environmental perturbation (light and temperature) over the course of the experiments.
Environmental regulation of leaf colour in red 35S:PAP1 Arabidopsis thaliana.
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