Proinflammatory phenotype of iPS cell-derived JAK2 V617F megakaryocytes induces fibrosis in 3D in vitro bone marrow niche
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ABSTRACT: In this dataset, we determine the global gene expression in human induced pluripotent stem (iPS) cell-derived CD61+ megakaryocytes carrying homozygous JAK2 V617F mutation or the JAK2 wildtype gene.
Project description:We performed bulk RNAseq of sorted megakaryocytes and subsequent Lin- cells to study the impact of the combination of Jak2 V617F mutations and Srsf2 P95H mutations
Project description:Pegylated interferon alpha (pegIFNα) can induce molecular remissions in JAK2-V617F-positive myeloproliferative neoplasms (MPN) patients by targeting long-term hematopoietic stem cells (LT-HSCs). Additional somatic mutations in genes regulating LT-HSC self-renewal, such as DNMT3A, have been reported to have poorer responses to pegIFNα. We investigated if DNMT3A loss leads to alterations in JAK2-V617F LT-HSCs functions conferring resistance to pegIFNα treatment in a mouse model of MPN and in hematopoietic progenitors from MPN patients. Long-term treatment with pegIFNα normalized blood parameters, reduced splenomegaly and JAK2-V617F-chimerism in single-mutant JAK2-V617F (VF) mice. However, pegIFNα in VF;Dnmt3aΔ/Δ (VF;DmΔ/Δ) mice worsened splenomegaly and failed to reduce JAK2-V617F-chimerism. Furthermore, LT-HSCs from VF;DmΔ/Δ mice compared to VF were less prone to accumulate DNA damage and exit dormancy upon pegIFNα treatment. RNA-sequencing showed that IFNα induced stronger upregulation of inflammatory pathways in LT-HSCs from VF;DmΔ/Δ compared to VF mice, indicating that the resistance of VF;DmΔ/Δ LT-HSC was not due to failure in IFNα signaling. Transplantations of bone marrow from pegIFNα treated VF;DmΔ/Δ mice gave rise to more aggressive disease in secondary and tertiary recipients. Liquid cultures of hematopoietic progenitors from MPN patients with JAK2-V617F and DNMT3A mutation showed increased percentages of JAK2-V617F-positive colonies upon IFNα exposure, whereas in patients with JAK2-V617F alone the percentages of JAK2-V617F-positive colonies decreased or remained unchanged. PegIFNα combined with 5-azacytidine only partially overcame resistance in VF;DmΔ/Δ mice. However, this combination strongly decreased the JAK2-mutant allele burden in mice carrying VF mutation only, showing potential to inflict substantial damage preferentially to the JAK2-mutant clone.
Project description:In this dataset, we compare the gene expression data of induced pluripotent stem (iPS) cell-derived CD61+ megakaryocytes carrying heterozygous or homozygous Calreticulin (CALR) ins5 mutations or the CALR wildtype gene.
Project description:We investigated if Dnmt3a loss leads to alterations in JAK2 V617F LT-HSCs heterogenity and expression profile using single-cell RNA sequencing.
Project description:The myeloproliferative disease polycythemia vera (PV) driven by the JAK2 V617F mutation can transform into myelofibrosis (post-PV-MF). It remains an open question how JAK2 V617F in hematopoietic stem cells induces MF. Megakaryocytes are major players in murine PV models but are difficult to study in the human setting. We generated induced pluripotent stem cells (iPSCs) from JAK2 V617F PV patients and differentiated them into megakaryocytes. In differentiation assays, JAK2 V617F iPSCs recapitulated the pathognomonic skewed megakaryocytic and erythroid differentiation. JAK2 V617F iPSCs had a TPO-independent and increased propensity to differentiate into megakaryocytes. RNA sequencing of JAK2 V617F iPSC-derived megakaryocytes reflected a proinflammatory, profibrotic phenotype and decreased ribosome biogenesis. In three-dimensional (3D) coculture, JAK2 V617F megakaryocytes induced a profibrotic phenotype through direct cell contact, which was reversed by the JAK2 inhibitor ruxolitinib. The 3D coculture system opens the perspective for further disease modeling and drug discovery.
Project description:The activation of PD-1 (Programmed Death receptor-1) on T cells can cause T cell exhaustion and immune tolerance. Some tumors up-regulate the expression of the ligand of PD-1, namely PD-L1 (Programmed Death Receptor-Ligand 1), thus preventing anti-tumor immune response and promoting immune-escape. Previous studies have shown that JAK2 (Janus Kinase 2) signaling can promote PD-L1 expression in Hodgkin Lymphoma. In Myeloproliferative Neoplasms (MPN), JAK2 is frequently characterized by the the presence of the point-mutation V617F, which leads to its constitutive activation and to uncontrolled cell proliferation and survival. Accordingly, tumor cell lines expressing JAK2 V617F express higher levels of PD-L1 as compared to tumor cell lines negative for such mutations. In this experiment, we transfected BaF3 cells with a vector (plasmid for Murine Stem Cell Virus) containing the gene for JAK2 with the point-mutation V617F. As control, we used BaF3 cells transfected with the same vector, but without the gene for JAK2 V617F (empty vector). Both the cell lines (with/without JAK2 V617F) were co-cultured with primary murine T cells. When co-cultured with BaF3 cells expressing JAK2 V617F, T cells upregulated genes connected to senescence pathways, showed increased apoptosis, less cytokine production, and displayed other forms of dysfunction which can be associated with the activation of PD-1.
Project description:Transcriptional profiling of transformed Ba/F3 cells by myeloproliferative neoplasm-associated JAK2 V617F mutant comparing control Ba/F3 cells expressing wild type JAK2. Two-condition experiment, WT cells vs. VF cells. One replicate per array.
Project description:We present cell line SET-2 as potential model system for DNA methylation analysis. This cell line was established from a patient with essential thrombocythemia at megakaryoblastic transformation and carries the JAK2 V617F mutation. Cell line SET-2 carries the DNMT3A R882H mutation, recurrent in cytogenetically normal AML.