Project description:Imatinib therapy is first-line treatment for chronic myeloid leukemia (CML), and its failure to target CML progenitor/stem cells may lead to an increased risk of relapse. We report here that fenretinide, a well-tolerated vitamin A derivative, is capable of eradicating primitive CML progenitor/stem cells and significantly enhances the efficacy of imatinib at physiologically achievable concentrations. As tested by colony forming cell assays, formation of various colonies derived primitive CML CD34+ cells was significantly suppressed by fenretinide, particularly with respect to the formation of colonies derived from erythroid progenitors and more primitive CML progenitor/stem cells. Also, fenretinide significantly enhanced the ability of imatinib to suppress the formation of the colonies. Moreover, fenretinide was able to induce apoptosis in primitive CML CD34+ cells while sparing the normal counterparts. In particular, primitive CML CD34+CD38- cells appeared to be most sensitive to fenretinide induced apoptosis. Through transcriptome analysis and molecular validation, we further showed that fenretinide induced apoptosis in CML CD34+ cells was probably mediated by a series of stress responsive events which were likely triggered by elevated levels of intracellular reactive oxygen species. Accordingly, the combination of fenretinide and imatinib may provide a potential solution for overcoming relapse and resistance in CML. Experiment Overall Design: Transcriptome profiles of CML CD34+ cells with and without fenretinide treatment were analyzed using whole genome expression arrays (Affymetrix HG-U133 Plus 2.0) in four CML patients (CML32, CML33, CML34 and CML35, see Table 1). To minimize potential data biases, both treated and untreated cell samples were maintained in culture for 48 hours before hybridization.
Project description:Monocytes can give rise to multiple highly specialized cell types to perform a wide array of functions, ranging from pathogen phagocytosis to bone resorption. This differentiation is induced by the binding of cytokines to dedicated receptors on the surface of monocytes, which results in the initiation of genetic programs that enable cells to perform their specialized functions. Given their common background, it is not surprising that monocyte-derived cells share abilities and cellular markers, yet their specialized functions require a dedicated set of proteins. In order to dissect the monocyte differentiation process and to define cell type-specific marker proteins, we differentiated circulating monocytes into dendritic cells, M1 and M2 macrophages, and osteoclasts, and assessed their proteomes by quantitative mass spectrometry throughout the differentiation process. Statistical analysis indicated that monocyte differentiation is a linear process characterized by a common core of proteins that is similarly affected among the distinct differentiation paths. Throughout the specialization process a cluster of RNA-binding and processing proteins was downregulated whereas proteins associated to metabolic processes were increased. Analysis of the specialized cells after 10 days of differentiation uncovered existing and putative novel dendritic cell markers. Combined, we here present a comprehensive proteomic analysis of monocyte differentiation uncovering shared and distinct proteomic features of differentiating monocytes and monocyte-derived cells.
Project description:Hematopoietic stem and progenitor cells (HPCs) can be maintained in vitro, but the vast majority of their progeny loses M-bM-^@M-^\stemnessM-bM-^@M-^] during culture. We have analyzed DNA methylation (DNAm) profiles of freshly isolated CD34+ cells and upon expansion on either tissue culture plastic (TCP) or mesenchymal stromal cells (MSCs). Cultured HPCs acquired significant DNA-hypermethylation, particularly in up-stream promoter regions and shore-regions of CpG islands (CGIs). To analyze if these DNAm changes are relevant for differential gene expression we analyzed gene expression profiles of additional samples. As expected highly expressed genes (10% with highest signal intensity in gene expression arrays) were hardly methylated at promoter regions, CGIs and shore-regions. 9 samples were hybridized GeneChip Human Gene 1.0 ST Arrays (Affymetrix)
Project description:Cord blood hematopoietic stem cells (CB-HSCs) are an outstanding source for transplantation approaches. However, the amount of cells per donor is limited and culture expansion of CB-HSCs is accompanied by a loss of engraftment potential. In order to analyze the molecular mechanisms leading to this impaired potential we profiled global and local epigenotypes during the expansion of human CB hematopoietic stem and progenitor cells (HPSCs). Human CB-derived CD34+ cells were cultured in serum-free medium together with SCF, TPO, FGF, with or without Igfbp2 and Angptl5 (STF/STFIA cocktails). As compared to the STF cocktail, the STFIA cocktail maintains in vivo repopulation capacity of cultured CD34+ cells. Upon expansion, CD34+ cells genome-wide remodel their epigenotype and depending on the cytokine cocktail, cells show different H3K4me3 and H3K27me3 levels. Expanding cells without Igfbp2 and Angptl5 leads to higher global H3K27me3 levels. ChIPseq analyses reveal a cytokine cocktail-dependent redistribution of H3K27me3 profiles. Inhibition of the PRC2 component EZH2 counteracts the culture-associated loss of NOD scid gamma (NSG) engraftment potential. Collectively, our data reveal chromatin dynamics that underlie the culture-associated loss of engraftment potential. We identify PRC2 component EZH2 as being involved in the loss of engraftment potential during the in vitro expansion of HPSCs. 6 samples were hybridized GeneChip Human Gene 1.0 ST Arrays (Affymetrix)
Project description:The derivation of functional, transplantable HSCs from an pluripotent stem cells in vitro holds great promise for clinical therapies, but is unachieved. In order to achieve full functionality of HSCs, it is vital to determine the extent to which PSCs can currently be differentiated to the HSC program in vitro and identify the remaining dysregulated genetic pathways. Microarrays were used to compare the transcritomes of ESC-derived immunophenotypic HSPCs to endogenous HSPCs from various stages of development to determine the programs important for human HSC development and function, and which programs were lacking in ESC-derived hematopoietic cells. CD34+CD38-CD43+CD90+ HSPCs were sorted from human placenta and embryoid bodies, and CD34+CD38-CD45+CD90+ HSPCs sorted from fetal liver and embryoid bodies co-cultured on OP9-M2 stroma, the RNA was extracted, library created and hybridized to the Affymetrix microarray
Project description:Hematopoietic stem and progenitor cells (HPCs) can be maintained in vitro, but the vast majority of their progeny loses M-bM-^@M-^\stemnessM-bM-^@M-^] during culture. In this study, we have analyzed DNA methylation (DNAm) profiles of freshly isolated CD34+ cells and upon expansion on either tissue culture plastic (TCP) or mesenchymal stromal cells (MSCs). DNAm profiles of expanded CD34+ versus CD34- subsets reflected hematopoietic differentiation, whereas culture on TCP or MSCs had little impact. Notably, all cultured HPCs - even those which remained CD34 positive - acquired significant DNA-hypermethylation, particularly in up-stream promoter regions, shore-regions of CpG islands, and binding sides for PU.1 and RUNX1. Our results point to a coordinated epigenetic process which needs to be controlled to enhance self-renewal of HPCs in vitro. 12 samples were hybridised to the Illumina Infinium 450k Human Methylation Beadchip
Project description:We derived B-lineage cells by in vitro culture of neonatal cord blood CD34+ cells on MS-5 stromal cells with recombinant IL-7. These cultures yielded CD19+CD127+ and CD19+CD127- cell populations. We performed gene expression profiling on these populations and compared these with each other and with published expression profiles of freshly isolated BM precursor B-cell subsets (E-MEXP-384). These analyses yielded new insights into their different functionality and developmental stage.<br><br>A file containing statistical analysis of the normalized data is included in the file named E-MEXP-2878.additional.zip on the FTP site for this experiment.
Project description:In the young field of single-cell proteomics (scMS), there is a great need for improved global proteome characterization, both in terms of proteins quantified per cell and quantitative performance thereof. The recently introduced real-time search (RTS) on the Orbitrap Eclipse Tribrid mass spectrometer in combination with SPS-MS3 acquisition has been shown to be beneficial for the measurement of samples that are multiplexed using isobaric tags. Multiplexed single-cell proteomics requires high ion injection times and high-resolution spectra to quantify the single-cell signal, however the carrier channel facilitates peptide identification and thus offers the opportunity for fast on-the-fly precursor filtering before committing to the time intensive quantification scan. Here, we compared classical MS2 acquisition against RTS-SPS-MS3, both using the Orbitrap Eclipse Tribrid MS with the FAIMS Pro ion mobility interface and we present a new acquisition strategy termed RETICLE (RTS Enhanced Quant of Single Cell Spectra) that makes use of fast real-time searched linear ion trap scans to preselect MS1 peptide precursors for quantitative MS2 Orbitrap acquisition. Here we show that classical MS2 acquisition is outperformed by both RTS-SPS-MS3 through increased quantitative accuracy at similar proteome coverage, and RETICLE through higher proteome coverage, with the latter enabling the quantification of over 1000 proteins per cell at a MS2 injection time of 750ms using a 2h gradient.