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.
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: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
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. Keywords: cell type comparison
Project description:LRF, which is encoded by the ZBTB7A gene and formerly known as POKEMON (POK erythroid myeloid ontogenic factor), was originally identified as a PLZF (promyelocytic leukemia zinc finger) homologue interacting with BCL6 (B-cell lymphoma 6). LRF is a transcription factor that is broadly expressed in hematopoietic lineage cells, but its expression is particularly high in erythroblasts and germinal center (GC) B-cells. The goal of this study is to assess the effect of LRF loss on the LT-HSC transcriptome. Nine days after injection of adult mice with polyinosinic polycytidylic acid (pIpc) to activate Cre, total RNAs were isolated from double-sorted LT-HSCs from LRF Flox/+ Mx1-Cre+ and LRF Flox/Flox Mx1-Cre+ mice and processed for microarray analysis.
Project description:LRF, which is encoded by the ZBTB7A gene and formerly known as POKEMON (POK erythroid myeloid ontogenic factor), was originally identified as a PLZF (promyelocytic leukemia zinc finger) homologue interacting with BCL6 (B-cell lymphoma 6). LRF is a transcription factor that is broadly expressed in hematopoietic lineage cells, but its expression is particularly high in erythroblasts and germinal center (GC) B-cells. The goal of this study is to assess the effect of LRF loss on the LT-HSC transcriptome. Nine days after injection of adult mice with polyinosinic polycytidylic acid (pIpc) to activate Cre, total RNAs were isolated from double-sorted LT-HSCs from LRF Flox/+ Mx1-Cre+ and LRF Flox/Flox Mx1-Cre+ mice and processed for microarray analysis. We performed gene expression microarray analysis of FACS-sorted LT-HSCs (LSK IL7Ra-Flt3-CD150+CD48-) to assess the effect of Lrf loss on the LT-HSC transcriptome. Zbtb7a Flox/+ Mx1-Cre+ mice were used as a control to normalize the potential effects of Cre recombinase. LT-HSCs were FACS-sorted from three Lrf knockout (Zbtb7a Flox/Flox Mx1-Cre+) and two control (Zbtb7a Flox/+ Mx1-Cre+) mice, nine days after the first pIpC injection.
Project description:All hematopoietic lineages are derived from a limited pool of hematopoietic stem cells (HSCs). Although the mechanisms underlying HSC self-renewal have been extensively studied, little is known about the role of protein glutamylation and deglutamylation in hematopoiesis. Here we show that carboxypeptidase CCP3 is most highly expressed in BM cells among CCP members. CCP3 deficiency impairs HSC self-renewal and hematopoiesis. Deubiquitinase BAP1 is a substrate for CCP3 in HSCs. BAP1 is glutamylated at Glu651 by TTLL5 and TTLL7, and BAP1-E651A mutation abrogates BAP1 glutamylation. BAP1 glutamylation accelerates its ubiquitination to trigger its degradation. CCP3 can remove glutamylation of BAP1 to promote its stability, which enhances Hoxa1 expression leading to HSC self-renewal. Bap1E651A mice produce higher numbers of LT-HSCs and peripheral blood cells. Moreover, TTLL5 and TTLL7 deficiencies sustain BAP1 stability to promote HSC self-renewal and hematopoiesis. Therefore, glutamylation and deglutamylation of BAP1 modulate HSC self-renewal and hematopoiesis.