Project description:Comparison of mRNA expression profiles of LT-HSCs with or without mutations in JAK2 and Ezh2 by RNA sequencing. LT-HSC mRNA was extracted from six different transgenic mice (SclCre, SclCre;Ezh2+/-, SclCre;Ezh2-/-, SclCre; JAK2V617F, SclCre; JAK2V617F;Ezh2+/-, SclCre; JAK2V617F;Ezh2-/-) 10 weeks after tamoxifen injection. Our study represents the first detailed analysis of mRNA expression profile of LT-HSC with or without mutations in JAK2 and Ezh2 , with biologic replicates, generated by RNA-seq technology. Our results revealed that mRNA expression profile of LT-HSC with different genotype showed specific gene expression patterns, which allows to do biological comprehensive and quantitative analysis for hematopoiesis. LT-HSCs mRNA profiles six different transgenic mice (SclCre, SclCre;Ezh2+/-, SclCre;Ezh2-/-, SclCre; JAK2V617F, SclCre; JAK2V617F;Ezh2+/-, SclCre; JAK2V617F;Ezh2-/-) were generated by deep sequencing.
Project description:Comparison of mRNA expression profiles of LT-HSCs with or without mutations in JAK2 and Ezh2 by RNA sequencing. LT-HSC mRNA was extracted from six different transgenic mice (SclCre, SclCre;Ezh2+/-, SclCre;Ezh2-/-, SclCre; JAK2V617F, SclCre; JAK2V617F;Ezh2+/-, SclCre; JAK2V617F;Ezh2-/-) 10 weeks after tamoxifen injection. Our study represents the first detailed analysis of mRNA expression profile of LT-HSC with or without mutations in JAK2 and Ezh2 , with biologic replicates, generated by RNA-seq technology. Our results revealed that mRNA expression profile of LT-HSC with different genotype showed specific gene expression patterns, which allows to do biological comprehensive and quantitative analysis for hematopoiesis.
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:The fate options of hematopoietic stem cells (HSCs) include self-renewal, differentiation, migration and apoptosis, but the interaction between intracellular Ca2+ and cytoplasmic chaperon protein in regulating fate options of long term-HSCs (LT-HSC) is unknown. We created a S100A6 conditional knockout mouse model in the hematopoietic system and our studies showed that in S100A6KO, the number of LT-HSCs was significantly reduced and HSCs engrafted poorly. After 5FU challenge, the frequency of S100A6KO HSCs remained significantly low. Our data showed that S100A6 failed to self-renew through Akt pathway in an intracellular calcium (Cai2+)-dependent manner. Expression profiling of S100A6KO obtained from gene signatures revealed that cytosolic calcium level and proteins translocation to mitochondria were decreased. Mitochondrial oxidative phosphorylation was impaired in S100A6KO. Proteomic data indicated Hsp90 protein and chaperonin family were reduced. Our findings demonstrated that S100A6 regulates fate options of HSCs self-renewal through integrating Akt signaling, specifically governing mitochondria metabolic function and protein quality.
Project description:Analysis of highly purified long-term hematopoietic stem cells (LT-HSCs) 2 hours after irradiation at 0Gy, 0.02Gy and 2.5Gy. Results provide insight into the molecular mechanisms underlying LT-HSCs immediate response to low doses of γ-irradiation compared to high doses.
Project description:Comparison of mRNA expression profiles of MEPs with or without mutations in JAK2 and Ezh2 by RNA sequencing. MEPs mRNA was extracted from six different transgenic mice (SclCre, SclCre;Ezh2+/-, SclCre;Ezh2-/-, SclCre; JAK2V617F, SclCre; JAK2V617F;Ezh2+/-, SclCre; JAK2V617F;Ezh2-/-) 10 weeks after tamoxifen injection. Our study represents the first detailed analysis of mRNA expression profile of MEP with or without mutations in JAK2 and Ezh2 , with biologic replicates, generated by RNA-seq technology. Our results revealed that mRNA expression profile of MEP with different genotype showed specific gene expression patterns, which allows to do biological comprehensive and quantitative analysis for hematopoiesis. MEPs mRNA profiles six different transgenic mice (SclCre, SclCre;Ezh2+/-, SclCre;Ezh2-/-, SclCre; JAK2V617F, SclCre; JAK2V617F;Ezh2+/-, SclCre; JAK2V617F;Ezh2-/-) were generated by deep sequencing.
Project description:Analysis of highly purified long-term hematopoietic stem cells (LT-HSCs) 2 hours after irradiation at 0Gy, 0.02Gy and 2.5Gy. Results provide insight into the molecular mechanisms underlying LT-HSCs immediate response to low doses of γ-irradiation compared to high doses. Three samples were analyzed and correlated with the control group (0Gy).
Project description:Analysis of highly purified long-term hematopoietic stem cells (LT-HSCs) irradiated at 0Gy, 0.02Gy, 0.1Gy and 0.5Gy six months after transplantation. Results provide insight into the molecular mechanisms underlying multiple aspects of LT-HSCs premature ageing after low doses of γ-irradiation (0.02Gy).
Project description:Analysis of highly purified long-term hematopoietic stem cells (LT-HSCs) irradiated at 0Gy, 0.02Gy, 0.1Gy and 0.5Gy six months after transplantation. Results provide insight into the molecular mechanisms underlying multiple aspects of LT-HSCs premature ageing after low doses of γ-irradiation (0.02Gy). Four samples were analyzed and correlated with the control group (0Gy).
Project description:Regulation of quiescence is critical for the maintenance of adult hematopoietic stem cells (HSCs). Previous studies by gene disruption during mouse embryonic development have shown that transcription factor gene Prdm16 is important for the generation/maintenance of fetal liver HSCs; however, the underlying mechanisms and the function of Prdm16 in adult HSCs remain unclear. To investigate the role of Prdm16 in adult HSCs, we generated a novel conditional knockout mouse model and deleted Prdm16 in adult mouse hematopoietic system using the interferon inducible Mx1-Cre. Our results show that deletion of Prdm16 leads to a gradual decline of adult HSC numbers and a concomitant increase in the multipotent progenitor (MPP) compartment. Prdm16 deletion in the hematopoietic system following transplantation produced the same phenotype indicating that the defect is intrinsic to the HSCs. This HSC loss was also exacerbated by stress induced by 5-FU injections. Annexin V staining showed no difference in apoptosis between wild type and knockout HSCs. In contrast, BrdU analysis revealed that loss of Prdm16 significantly increases cycling of long-term HSCs (LT-HSCs) with majority of the cells found in the S to G2/M phase. Consistently, RNA-seq analysis of mouse LT- HSCs with and without Prdm16 deletion showed that Prdm16 loss induced a significant decrease in the expression of several known cell cycle regulators of HSCs, among which Cdkn1a and Egr1 were further identified as direct targets of Prdm16. Our results suggest that Prdm16 preserves the function of adult LT-HSCs by promoting their quiescence.