Transcription profiling by array of purified CD34+ cell lines (Cord Blood CD34+) treated with ExtracellularVescicles (EVs) isolated from bone marrow mesenchymal stem cells (BM-MSC)
ABSTRACT: Transcription profiling analysis was performed on purified CD34+ cell lines (Cord Blood CD34+) treated with ExtracellularVescicles (EVs) isolated from bone marrow mesenchymal stem cells (BM-MSC).
Project description:Although it has been shown that HIF1 and 2 fulfill essential roles within the hematopoietic system and in the regulation of HSC fate, little is currently known about the specific mechanisms that are involved. We identified transcriptome changes induced by hypoxia, constitutively active HIF1(P402/564) and HIF2(P405/531) in human cord blood CD34+ cells. Thus, we were able to identify common hypoxia-HIF1-HIF2 gene signatures, but we also identified specific target genes that were exclusively regulated by HIF1, HIF2 or hypoxia. CB CD34+ cells were isolated by Miltenyi miniMACS column. Cells were prestimulated in HPGM with 100 ng/ml KITL, FLT3L and TPO for 3 days after which cells were placed either at normoxia or hypoxia (1% O2 for an additional 24 hrs). 5 independent CB CD34+ batches were used and isolated RNA was combined and used for Illumina beadhchip arrays HT12 v4
Project description:Although it has been shown that HIF1 and 2 fulfill essential roles within the hematopoietic system and in the regulation of HSC fate, little is currently known about the specific mechanisms that are involved. We identified transcriptome changes induced by hypoxia, constitutively active HIF1(P402/564) and HIF2(P405/531) in human cord blood CD34+ cells. Thus, we were able to identify common hypoxia-HIF1-HIF2 gene signatures, but we also identified specific target genes that were exclusively regulated by HIF1, HIF2 or hypoxia. CB CD34+ cells were isolated by Miltenyi miniMACS column. Cells were prestimulated in HPGM with 100 ng/ml KITL, FLT3L and TPO for 48 hrs. Cells were transduced with control pRRL-IRS2-EGFP lentiviral vectors or vectors expressing HIF1α(P402A,P564A) or HIF2α(P405A,P531A) in one or two rounds of 12 hrs each. 24 hrs later transduced cells were sorted after which RNA was isolated. 5 independent CB CD34+ batches were isolated, transduced and sorted, and isolated RNA was combined and used for Illumina beadhchip arrays HT12 v4
Project description:Bone marrow (BM) mesenchymal stromal cells (BM-MSC) upregulate their NF-κB signaling to protect leukemia cells from chemotherapy-induced apoptosis. To elucidate molecular mechanisms by which leukemia-stroma interactions within the BM microenvironment could confer chemoresistance to leukemia cells, we used genome-wide gene expression profiling (GEP) to examine human normal BM-MSC that had been co-cultured with the pre-B ALL REH cells and then separated by flow cytometry (FACS). GEP results for co-cultured cells of each type were compared to GEP results for cells of the corresponding type cultured alone, and taken through the same FACS purification procedure, to identify changes in gene expression profiles caused by co-culture.
Project description:Tyrosine kinase inhibitors (TKI) are highly effective in treatment of chronic myeloid leukemia (CML) but do not eliminate leukemia stem cells (LSC), which remain a potential source of relapse. TKI treatment effectively inhibits BCR-ABL kinase activity in CML LSC, suggesting that additional kinase-independent mechanisms contribute to LSC preservation. We investigated whether signals from the bone marrow (BM) microenvironment protect CML LSC from TKI treatment. Coculture with human BM mesenchymal stromal cells (MSC) significantly inhibited apoptosis and preserved CML stem/progenitor cells following TKI exposure, maintaining colony forming ability and engraftment potential in immunodeficient mice. We found that the N-Cadherin receptor plays an important role in MSC-mediated protection of CML progenitors from TKI. N-Cadherin-mediated adhesion to MSC was associated with increased cytoplasmic N-Cadherin-β-catenin complex formation, as well as enhanced β-catenin nuclear translocation and transcriptional activity. Increased exogenous Wnt-mediated β-catenin signaling played an important role in MSC-mediated protection of CML progenitors from TKI treatment. Our results reveal a close interplay between N-Cadherin and the Wnt-β-catenin pathway in protecting CML LSC during TKI treatment. Importantly, these results reveal novel mechanisms of resistance of CML LSC to TKI treatment, and suggest new targets for treatment designed to eradicate residual LSC in CML patients. RNA was obtained from CML CD34+ cells treated with or without IM (5μM) and MSC for 96 hours, amplified, labeled and hybridized to GeneChip 1.0 arrays (Affymetrix, Santa Clara, CA). Microarray data analysis was performed using R (version 2.9) with genomic analysis packages from Bioconductor (version 2.4). The 33297 probes represented on the microarray were filtered by cross-sample mean, and for standard deviation of greater than the 25% quantile, yielding 18624 probes representing 12553 genes. Linear regression was used to model the gene expression with the consideration of a 2x2 factorial design and matched samples. Differentially expressed genes were identified by calculating empirical Bayes moderated t-statistic, and p-values were adjusted by FDR using the “LIMMA” package. Gene Set Enrichment Analysis (GSEA) was performed using GSEA software version 2.04 to detect enrichment of predetermined gene sets using t-scores from all genes for 1263 gene sets in the C2 (curated gene sets) category from the Molecular Signature Database (MsigDB).
Project description:Comparison of gene expression profiling analysis of bone marrow isolated CD34+ cells from patients with MALT lymphoma vs. healthy individuals revealed a large number of differentially expressed genes that included NF-kB target genes, genes involved in inflamatory signalling and immunoglobulin genes, suggesting an early lymphoid B-cell priming. Chromosomal translocations involving MALT1 gene are hallmarks of mucosa-associated lymphoid tissue (MALT) lymphoma. However, targeting these translocations to mouse B-cells has failed to reproduce human disease. Here, we induced MALT1 expression in mouse Sca1+Lin- hematopoietic stem/progenitor cells (HS/PCs), leading to the development of tumors recapitulating the clinical, histopathological and molecular features of human MALT lymphomas. Ablation of the p53 gene induced transformation of MALT lymphoma to diffuse large-cell lymphoma of activated B-cell type (ABC-DLBCL). Human CD34+ cells isolated from MALT lymphoma patients displayed an abnormal transcriptional program that was shared by MALT lymphoma cells, transgenic mouse Sca1+Lin- cells and Sca1-MALT1-induced lymphomas. Our study shows that MALT lymphoma can be modeled in mice by targeting MALT1 oncogene to HS/PCs. 10 samples were analyzed of which 5 are CD34+ cells sorted from the bone marrow of MALT patients and are compared to the other 5 CD34+ cells sorted from the bone marrow of healthy donors.
Project description:Regenerative medicine in aims to restore structure and function to tissues or organs damaged by time, disease or injury. Stem cells have great potential for tissue repair and regeneration, why they are intensely investigated in equine clinical research. However, before any type of stem cell can be applied in practice, it is crucial that the isolated stem cells have been definitively characterised by a set of specific functional or phenotypic markers. This project includes a surface mapping of equine mesenchymal (MSC) stem cell surface proteome.