Enforced Expression of NUP98-HOXA10hd Fusion Gene in Multipotent Progenitors Support Long-term Hematopoiesis in primary mice [MPP]
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ABSTRACT: Allogenic hematopoietic stem cell (HSC) transplantation is widely used for treatment of blood disorders to re-establish long-term multi-lineage hematopoiesis. Enhance self-renewal potential of progenitor population to support hematopoiesis offer an alternative and complementary approach to achieve similar or enhance therapeutic effects. Nup98-Hoxa10hd fusion gene (NA) has been shown to confer expansion, anti-stress response and engraftment competitiveness on HSC. However, whether the ectopic expression of NA in multipotent progenitors (MPPs) could enhance their self-renewal potential and confer long-term multi-lineage hematopoiesis remains unknown. In this study, we showed that ectopic expression in MPPs confer long-term multi-lineage hematopoiesis in recipient mice. We further showed that NA upregulated pathways of cell cycle regulation, epigenetic regulation and response to stress in MPPs. These molecular traits increased the self-renewal potential of NA MPPs, which resulting in production of lineage-maintaining committed progenitor cells. Transcriptome analysis of NA myeloid progenitors identified genes regulating hematopoiesis, homeostasis, phosphorylation. In summary, we show that ectopic expression of Nup98-Hoxa10hd fusion gene enhance self-renewal potential of MPPs thus confer long-term multi-lineage repopulating capacity on MPPs, offering promising means to involve MPPs to augment cell source in clinical transplantation settings.
Project description:Allogenic hematopoietic stem cell (HSC) transplantation is widely used for treatment of blood disorders to re-establish long-term multi-lineage hematopoiesis. Enhance self-renewal potential of progenitor population to support hematopoiesis offer an alternative and complementary approach to achieve similar therapeutic effects. Nup98-Hoxa10hd fusion gene (NA) has been shown to confer expansion, anti-stress response and engraftment competitiveness on HSC. However, whether the ectopic expression of NA in multipotent progenitors (MPPs) could enhance their self-renewal potential and confer long-term multi-lineage hematopoiesis remains unknown. In this study, we showed that ectopic expression in MPPs confer long-term multi-lineage hematopoiesis in recipient mice. We further showed that NA upregulated pathways of cell cycle regulation, epigenetic regulation and response to stress in MPPs. These molecular traits increased the self-renewal potential of NA MPPs, which resulting in production of lineage-maintaining committed progenitor cells. Transcriptome analysis of NA myeloid progenitors identified genes regulating hematopoiesis, homeostasis, phosphorylation. In summary, we show that ectopic expression of Nup98-Hoxa10hd fusion gene enhance self-renwal potential of MPPs thus confer long-term multilineage repopulating capacity on MPPs, offering promising means to involve MPPs to augment cell source in clinical transplantation settings.
Project description:Loss of Tet1 expression causes global 5mC and 5hmC changes in stem and progenitor cells in mice and enhanced pro-B cell self-renewal, increased DNA damage and B-lymphomageneis. In this study we performed whole transciptome analysis using RNA-sequencing in purified long-term HSCs and MPPs. These results revealed that genes regulated byTet1 included Histones, DNA repair enzymes and B-lineage specific factors.
Project description:Loss of Tet1 expression causes global 5mC and 5hmC changes in stem and progenitor cells in mice and enhanced pro-B cell self-renewal, increased DNA damage and B-lymphomageneis. In this study we performed whole transciptome analysis using RNA-sequencing in purified long-term HSCs and MPPs. These results revealed that genes regulated byTet1 included Histones, DNA repair enzymes and B-lineage specific factors. Purified long-term HSCs and MPPs from WT and Tet1 KO mice were used for RNA isolation. RNA was extracted using RNeasy kit (Qiagen) and PolyA selection using oligo-dT beads (Life Technologies) was performed according to the manufacturer’s instructions. Libraries were generated as described before, including end-repair, A-tailing, adapter (Illumina Truseq system) ligation and PCR amplification. RNA libraries were then sequenced on the Illumina HiSeq 2000 using 50bp paired-end reads. Transcriptome profiling of LT-HSC and MPP cells in WT and Tet1 KO mice
Project description:Umbilical cord blood (CB) is a non-invasive, convenient and broadly used source of hematopoietic stem cells (HSCs) for allogeneic stem cell transplantation. However, limiting numbers of HSCs remain a major constraint for its clinical application. One feasible option would be to expand HSCs to improve therapeutic outcome, however available protocols and the molecular mechanisms governing the self-renewal of HSC are unclear. Here we show that ectopic expression of a single miRNA, miR-125a, in purified murine and human multipotent progenitors (MPP) resulted in increased self-renewal and robust long-term multi-lineage repopulation in transplanted recipient mice. Using quantitative proteomics and Western blot analysis, we identified a restricted set of miR-125a targets which revealed the involvement of the MAP kinase signaling pathway in conferring long-term repopulating capacity to multipotent progenitors in human and mice. Our findings offer the innovative potential to use MPP with enhanced self-renewal activity to augment limited sources of HSC to improve clinical protocols.
Project description:The balance of self-renewal and differentiation is crucial to ensure the homeostasis of the hematopoietic system, and is a key hallmark of hematopoietic stem cells (HSCs); however, the underlying molecular pathways are not completely understood, including the role of micro-RNAs. To assess micro-RNA contributions, we performed micro-RNA profiling of HSCs and their immediate downstream progeny multi-potent progenitors (MPPs) from wild type control and Pbx1-conditional knockout mice, whose HSCs display a profound self-renewal defect.
Project description:Estrogens are potential regulators of the hematopoietic stem cell (HSC) niche and have effects on mature hematopoietic cells; however, whether estrogen signaling directly regulates normal and malignant HSC remains unclear. We demonstrate differential expression and specific roles of estrogen receptors (ER) in hematopoietic progenitors. ERa activation in short-term HSC and multipotent progenitors induced apoptosis. In contrast, the selective ER modulator (SERM) tamoxifen induced proliferation of quiescent long-term HSC, altered their self-renewal signature and compromised hematopoietic reconstitution following myelotoxic stress. Treatment with tamoxifen alone abolished hematopoietic progenitor expansion induced by JAK2V617F by restoring normal levels of apoptosis, blocked JAK2V617F-induced myeloproliferative neoplasm in vivo, and sensitized MLL-AF9+ leukemias to chemotherapy. Tamoxifen showed selective effects on mutant cells compared to normal ones, and had only a minor impact on steady-state hematopoiesis in disease-free animals. These results uncover specific regulation of hematopoietic progenitors by estrogens and potential anti-leukemic properties of SERM LT-HSCs, ST-HSCs and MPPs sorted from the bone marrow of mice treated with tamoxifen or vehicle (3 biological replicates per group)
Project description:During adult bone marrow hematopoiesis, extremely rare and dormant hematopoietic stem cells (HSCs) harbor the highest self-renewal activity within all blood cells. They give rise to active HSCs, which generate multipotent progenitors (MPPs) which differentiate into lineage-committed progenitors and subsequently mature cells. While HSCs are characterized by long-term self-renewal capacity, quiescence and multipotency, MPPs show steadily decreasing self-renewal activity, are cycling but are thought to maintain multipotency. To establish a comprehensive genome-wide landscape of expressed transcripts, we performed a quantitative transcriptome analysis by next-generation sequencing (RNA-seq) of seven ex vivo FACS-sorted mouse HSC/progenitor populations. Eleven-fold coverage of the genome was achieved, revealing quantification of > 27,000 mRNA species of which 589 long non-coding RNAs (lncRNAs) were quantified. A profile of 79 differentially expressed lncRNAs in HSC-MPPs was identified suggesting a role for these RNA species in HSC/progenitor biology. Expression clusters of transcription factors and cell adhesion molecules are identified between the different cell populations. Dormant HSCs, as identified by label-retaining assays, showed a highly differential expression profile compared to active HSCs. In addition to >200 differentially expressed cell surface receptors and lncRNAs, processes including metabolism, development, immune response, signaling (TGFb, Kit, senescence/autophagy) are distinct between the two types of HSCs. In addition, using whole cell proteome analysis of FACS-sorted HSCs and MPP1, >6,000 proteins were identified by quantitative tandem mass spectrometry. Quantification of these proteins confirmed the close relationship between these cell types also seen in their transcript profile and revealed processes such as energy metabolism, immune response and cell cycle to be modulated along early lineage progression. While MPP1/2 still show multilineage potential in reconstitution experiments, a strong lineage bias and low self-renewal potential is observed in mice reconstituted with MPP3/4. These functional differences are accompanied by complex changes in their transcriptome and is also revealed by principal component analysis. In summary, the global mRNA, lncRNA and proteome signatures uncovered here and which are complemented by functional assays, provide a comprehensive and searchable resource of the molecular make-up of the entire HSC/progenitor population present in the bone marrow. These data will provide the basis for a global understanding of stem cell biology in the adult blood system. The uploaded dataset corresponds to the quantitative proteomic comparison of HSC and MPP1, which was done in three biological replicates. Data analysis: MS raw data files were processed with MaxQuant (version 1.3.0.5) (Cox and Mann 2008). Enzyme specificity was set to trypsin/P and a maximum of two missed cleavages were allowed. Cysteine carbamidomethylation and methionine oxidation were selected as fixed and variable modifications, respectively. The derived peak list was searched using the built-in Andromeda search engine (version 1.3.0.5) in MaxQuant against the Uniprot mouse database (2013.02.20) containing 75,721 proteins to which 247 frequently observed contaminants as well as reversed sequences of all entries had been added. Initial maximal allowed mass tolerance was set to 20 ppm for peptide masses, followed by 6 ppm in the main search, and 0.5 Dalton for fragment ion masses. The minimum peptide length was set to six amino acid residues and three labeled amino acid residues were allowed. A 1% false discovery rate (FDR) was required at both the protein level and the peptide level. In addition to the FDR threshold, proteins were considered identified if they had at least one unique peptide. The protein identification was reported as an indistinguishable “protein group” if no unique peptide sequence to a single database entry was identified. The ‘match between runs’ was enabled for consecutive peptide fractions with a 2 minutes time window. The iBAQ algorithm was used for estimation of the abundance of different proteins within a single sample (proteome) (Schwanhausser 2011). For evaluation of differential protein expression between HSC and MPP1, statistical analysis was performed for the proteins quantified in all three replicates using the Limma package in R/Bioconductor (Gentleman 2004, Smyth 2004). After fitting a linear model to the data, an empirical Bayes moderated t-test was used for the protein ratios, which were weighted on log10(summed peptide intensities) in order to capture the effect that the statistical spread of unregulated proteins is much more focused for highly abundant proteins than for low abundance ones (Cox 2008). P-values were then adjusted for multiple testing with Benjamini and Hochberg's method and proteins with an adjusted p-value lower than 0.1 were considered to be differentially expressed between HSC and MPP1. Associated transcriptomics data has been deposited at ArrayExpress with accession E-MTAB-2262.
Project description:Endomucin (EMCN) currently represents the only hematopoietic stem cell (HSC) marker expressed by both murine and human HSCs. Here, we report that EMCN+ long-term repopulating HSCs (LT-HSCs; CD150+CD48−LSK) have a higher long-term multi-lineage repopulating capacity compared to EMCN− LT-HSCs. Cell cycle analyses and transcriptional profiling demonstrated that EMCN+ LT-HSCs were more quiescent compared to EMCN− LT-HSCs. Emcn−/− and Emcn+/+ mice displayed comparable steady-state hematopoiesis, as well as frequencies, transcriptional programs, and long-term multi-lineage repopulating capacity of their LT-HSCs. Complementary functional analyses further revealed increased cell cycle entry upon treatment with 5-fluorouracil and reduced granulocyte colony-stimulating factor (GCSF) mobilization of Emcn−/− LT-HSCs, demonstrating that EMCN expression by LT-HSCs associates with quiescence in response to hematopoietic stress and is indispensable for effective LT-HSC mobilization. Transplantation of wild-type bone marrow cells into Emcn−/− or Emcn+/+ recipients demonstrated that EMCN is essential for endothelial cell-dependent maintenance/self-renewal of the LT-HSC pool and sustained blood cell production post-transplant.
Project description:Endomucin (EMCN) currently represents the only hematopoietic stem cell (HSC) marker expressed by both murine and human HSCs. Here, we report that EMCN+ long-term repopulating HSCs (LT-HSCs; CD150+CD48−LSK) have a higher long-term multi-lineage repopulating capacity compared to EMCN− LT-HSCs. Cell cycle analyses and transcriptional profiling demonstrated that EMCN+ LT-HSCs were more quiescent compared to EMCN− LT-HSCs. Emcn−/− and Emcn+/+ mice displayed comparable steady-state hematopoiesis, as well as frequencies, transcriptional programs, and long-term multi-lineage repopulating capacity of their LT-HSCs. Complementary functional analyses further revealed increased cell cycle entry upon treatment with 5-fluorouracil and reduced granulocyte colony-stimulating factor (GCSF) mobilization of Emcn−/− LT-HSCs, demonstrating that EMCN expression by LT-HSCs associates with quiescence in response to hematopoietic stress and is indispensable for effective LT-HSC mobilization. Transplantation of wild-type bone marrow cells into Emcn−/− or Emcn+/+ recipients demonstrated that EMCN is essential for endothelial cell-dependent maintenance/self-renewal of the LT-HSC pool and sustained blood cell production post-transplant.
Project description:Endomucin (EMCN) currently represents the only hematopoietic stem cell (HSC) marker expressed by both murine and human HSCs. Here, we report that EMCN+ long-term repopulating HSCs (LT-HSCs; CD150+CD48−LSK) have a higher long-term multi-lineage repopulating capacity compared to EMCN− LT-HSCs. Cell cycle analyses and transcriptional profiling demonstrated that EMCN+ LT-HSCs were more quiescent compared to EMCN− LT-HSCs. Emcn−/− and Emcn+/+ mice displayed comparable steady-state hematopoiesis, as well as frequencies, transcriptional programs, and long-term multi-lineage repopulating capacity of their LT-HSCs. Complementary functional analyses further revealed increased cell cycle entry upon treatment with 5-fluorouracil and reduced granulocyte colony-stimulating factor (GCSF) mobilization of Emcn−/− LT-HSCs, demonstrating that EMCN expression by LT-HSCs associates with quiescence in response to hematopoietic stress and is indispensable for effective LT-HSC mobilization. Transplantation of wild-type bone marrow cells into Emcn−/− or Emcn+/+ recipients demonstrated that EMCN is essential for endothelial cell-dependent maintenance/self-renewal of the LT-HSC pool and sustained blood cell production post-transplant.