Project description:Analysis of HSCs from control and c-myc N-myc deficient long-term hematopoietic stem cells. HSCs lacking both c-myc and N-myc display increased apoptosis rates. Data provide insight into the molecular changes occuring upon complete loss of Myc activity, clarifying the resulting apoptotic mechanism and the role of Myc family proteins in HSCs. LT-HSC (Lin-Sca1+CD150+CD48-) cells were sorted from the BM of MxCre c-myc flox2 N-myc flox2 (experimental) and c-myc flox2 N-myc flox2 (control) mice 3 days after the last pI-pC injection. Each condition was analysed in triplicates, with each replicate consisting of a pool of 3 dKO mice or 2 control mice.
Project description:Analysis of HSCs from control and c-myc N-myc deficient long-term hematopoietic stem cells. HSCs lacking both c-myc and N-myc display increased apoptosis rates. Data provide insight into the molecular changes occuring upon complete loss of Myc activity, clarifying the resulting apoptotic mechanism and the role of Myc family proteins in HSCs and commited progenitors.
Project description:Purpose: The goal of this study is to compare NGS-derived transcriptome profiling (RNA-seq) of Ltbr-deficient and -proficient LT/ST-HSCs isolated from chimeric mice. Methods: Transcriptomic profiles of Ltbr-/- and Ly5.1 LT/ST-HSCs isolated from chimeric mice 6 weeks after reconstitution were assessed in triplicate by deep sequencing, using Illumina NextSeq 500. qRT–PCR validation was performed using TaqMan and SYBR Green assays. Results: We mapped about 60 million sequence reads per sample to the mouse genome (GRCm38 - mm10) and identified expressed transcripts in Ltbr-/- and Ly5.1 LT/ST-HSCs isolated from chimeric mice. RNA-seq. data confirmed stable expression of known housekeeping genes. Differentially expressed genes between the Ltbr-/- and Ly5.1 LT/ST-HSCs were identified with a fold change ≥1.5 and FDR p-value <0.05. Conclusions: Our study represents the first detailed transcriptome analysis of Ltbr-deficient and -proficient LT/ST-HSCs, with biologic replicates, generated by RNA-seq. technology. Our results show that Ltbr signaling regulates HSC proliferation and differentiation. Evaluation of mRNA content in Ltbr-/- LT/ST-HSCs revealed that Ltbr-deficiency enhances HSC proliferation, differentiation, cell cycle and reduces the activity of canonical NFkB signaling.
Project description:Self-renewal is a defining characteristic of stem cells, however the molecular pathways underlying its regulation are poorly understood. Here we demonstrate that conditional inactivation of the Pbx1 proto-oncogene in the hematopoietic compartment results in a progressive loss of long-term hematopoietic stem cells (LT-HSCs) that is associated with concomitant reduction in their quiescence, leading to a defect in the maintenance of self-renewal as assessed by serial transplantation. Transcriptional profiling revealed that multiple stem cell maintenance factors are perturbed in Pbx1-deficient LT-HSCs, which prematurely express a large subset of genes, including cell cycle regulators, normally expressed in non-self-renewing multipotent progenitors. A significant proportion of Pbx1-dependent genes are associated with the Tgf-b pathway, which serves a major role in maintaining HSC quiescence. Pbx1-deficient LT-HSCs are unable to up-regulate the cyclin dependent kinase inhibitor p57 in response to Tgf-b, providing a mechanism through which Pbx1 maintenance of stem cell self-renewal is achieved. Experiment Overall Design: Highly efficient Pbx1 deletion was induced with poly(I:C) in 3 young MxCre+.Pbx1f/f mutant or 2 MxCre-.Pbx1f/f control mice. LT-HSC (Lin-cKit+Sca1+CD34-CD135-) cells were prospectively sorted from bone marrow of individual mice harvested 4 weeks after the last injection of poly(I:C).
Project description:Self-renewal is a defining characteristic of stem cells, however the molecular pathways underlying its regulation are poorly understood. Here we demonstrate that conditional inactivation of the Pbx1 proto-oncogene in the hematopoietic compartment results in a progressive loss of long-term hematopoietic stem cells (LT-HSCs) that is associated with concomitant reduction in their quiescence, leading to a defect in the maintenance of self-renewal as assessed by serial transplantation. Transcriptional profiling revealed that multiple stem cell maintenance factors are perturbed in Pbx1-deficient LT-HSCs, which prematurely express a large subset of genes, including cell cycle regulators, normally expressed in non-self-renewing multipotent progenitors. Experiment Overall Design: LT-HSC (Lin-cKit+Sca1+CD34-CD135-) and ST-HSC (Lin-cKit+Sca1+CD34+CD135-) cells were prospectively sorted from the BM of MxCre-.Pbx1f/f control mice harvested 4 weeks after the last injection of poly(I:C).
Project description:Self-renewal is a defining characteristic of stem cells, however the molecular pathways underlying its regulation are poorly understood. Here we demonstrate that conditional inactivation of the Pbx1 proto-oncogene in the hematopoietic compartment results in a progressive loss of long-term hematopoietic stem cells (LT-HSCs) that is associated with concomitant reduction in their quiescence, leading to a defect in the maintenance of self-renewal as assessed by serial transplantation. Transcriptional profiling revealed that multiple stem cell maintenance factors are perturbed in Pbx1-deficient LT-HSCs, which prematurely express a large subset of genes, including cell cycle regulators, normally expressed in non-self-renewing multipotent progenitors. A significant proportion of Pbx1-dependent genes are associated with the Tgf-b pathway, which serves a major role in maintaining HSC quiescence. Pbx1-deficient LT-HSCs are unable to up-regulate the cyclin dependent kinase inhibitor p57 in response to Tgf-b, providing a mechanism through which Pbx1 maintenance of stem cell self-renewal is achieved. Keywords: genetic modification