Project description:Delineating key HSC regulators is of significant interest for informing the treatment of hematologic malignancy. While HSC activity is enhanced by overexpression of SKI, the transforming growth factor-beta (TGFβ) signaling antagonist corepressor, its requirement in HSC is unknown. Here we reveal a profound defect in Ski-/- HSC fitness but not specification. Transcriptionally, Ski-/- HSC exhibited striking upregulation of TGFb superfamily signaling and splicing alterations. As these are both common aspects of myelodysplastic-syndrome (MDS) pathobiology with prognostic value, we investigated the role of SKI in MDS. A SKI-correlated gene signature defines a subset of low-risk MDS patients with active TGFβ signaling and deregulated RNA splicing (e.g. CSF3R). The apparent paradox of Ski-/- HSC sharing molecular aspects of MDS with elevated SKI-mRNA is resolved by miR-21 targeting of SKI in MDS. We conclude that miR-21-mediated loss of SKI contributes to early stage MDS pathogenesis by activating TGFβ signaling and alternative splicing while hindering HSC fitness.
Project description:Myelodysplastic syndromes (MDS) are a group of incurable hematopoietic stem cell (HSC) neoplasms characterized by peripheral blood cytopenias and a high risk of progression to acute myeloid leukemia. MDS represent the final stage in a continuum of HSCs’ genetic and functional alterations and are preceded by a premalignant phase, clonal cytopenia of undetermined significance (CCUS). Dissecting the mechanisms of CCUS maintenance may uncover therapeutic targets to delay or prevent malignant transformation. Here, we demonstrate that DNMT3A and TET2 mutations, the most frequent mutations in CCUS, induce aberrant HSCs’ differentiation towards the myeloid lineage at the expense of erythropoiesis by upregulating IL-1b–mediated inflammatory signaling and that canakinumab rescues red blood cell transfusion dependence in early-stage MDS patients with driver mutations in DNMT3A and TET2. This study illuminates the biological landscape of CCUS and offers an unprecedented opportunity for MDS intervention during its initial phase, when expected survival is prolonged.
Project description:Analysis of musashi2 contribution towards maintaing myelodysplastic phenotype in stem cells. We find that musashi2 plays an integral role in maintaining the myelodysplastic phenotype
Project description:Analysis of Lin-c-Kit+Sca-1- haematopoietic stem cells (HSCs) expressing the Nup98-HoxD13 (NHD13) fusion gene. NHD13 induces myelodysplastic syndrome (MDS) in mice. Results provide insight into the molecular basis of the myelodysplastic phenotype WT mouse HSCs were compared to an NHD13 mutant sequenced in triplicate on a HiSeq 2000
Project description:Analysis of musashi2 contribution towards maintaing myelodysplastic phenotype in stem cells. We find that musashi2 plays an integral role in maintaining the myelodysplastic phenotype Control, NUP98-HOXD13; NHD13, NHD13/MSI2 bone marrow was transplated allowed to engraft into lethally irradiated congenic CD45.1 animals. Mice were then fed doxycycline to induce MSI2 overexpression. Mice were induced for 3 months and then CD45.2 Lineage lo Sca1+ and Kit+ cells were sorted and then assessed for gene expression.
Project description:Analysis of Lin-c-Kit+Sca-1- haematopoietic stem cells (HSCs) expressing the Nup98-HoxD13 (NHD13) fusion gene. NHD13 induces myelodysplastic syndrome (MDS) in mice. Results provide insight into the molecular basis of the myelodysplastic phenotype
Project description:Improved understanding of mechanisms regulating myelodysplastic syndrome (MDS) hematopoietic stem/progenitor cell (HSPC) growth and self-renewal is critical for developing MDS therapy. We revealed a novel regulatory axis that SIRT1-deficiency induced TET2 hyperacetylation promotes MDS HSPC functions, and provide an approach to target MDS HSPCs by activating SIRT1 deacetylase.
Project description:In this project we are investigating the mechanism of drought tolerance in rice at early vegetative stage by looking into expression profile of DEGs and uniquely expressed genes