Project description:Gene expression profiles from the aortic arch of Ldlr-/-Apob100/100 Mttpflox/flox Mx1-Cre mice at different stages of atherosclerosis development
Project description:Gene expression profiles from the aortic arch of Ldlr-/-Apob100/100 Mttpflox/flox Mx1-Cre mice at different stages of atherosclerosis development Total RNAs from the aortic arch were collected at different time points during atherosclerosis development (10, 20, 30, 40, 50, and 60 weeks of age), 4-7 mice per time point.
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: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:Analysis of the transcriptional signature of FACS-purified splenic DC subsets from Ldlr deficient mice transplanted with control or Cd11c-cre Atg16l1flox/flox bone marrow and subjected to an atherogenic diet for 8 weeks
Project description:In this study, mice with different genotypes and fed diets with different lipid content were enrolled, aiming to set up an atlas of miRNA expression levels in different organs with a relevant role in lipid/lipoprotein metabolism. Specifically, three genotypes were investigated: C57Bl/6 mice as controls, together with mice knock-out (KO) for LDLr (low-density lipoprotein receptor) and for PCSK9 (proprotein convertase subtilisin/kexin type 9). LDLr and PCSK9 are both involved in LDL turnover, the former mediating LDL clearance [PMID: 19299327], the latter causing the degradation of the LDLr protein [PMID: 17080197]. As a result, LDLrKO mice, because of their impaired LDL catabolism, are hypercholesterolemic and prone to atherosclerosis development, particularly when fed high-fat, cholesterol-containing diets [PMID: 8349823; PMID: 8182121]. On the contrary, PCSK9KO mice, characterized by an accelerated LDL catabolism, are hypocholesterolemic and atherosclerosis resistant [PMID: 15805190]. miRNA expression was investigated in liver, intestine, aorta, white adipose tissue and brain of mice on both standard and Western diet.
Project description:Quiescent hematopoietic stem cells (HSCs) are prone to mutagenesis, and accumulation of mutations can result in hematological malignancies. The mechanisms through which HSCs prevent such detrimental accumulation, however, are unclear. Here, we show that Aspp1 coordinates with p53 to maintain the genomic integrity of the HSC pool. Aspp1 is preferentially expressed in HSCs and restricts HSC pool size by attenuating self-renewal under steady state conditions. After genotoxic stress, Aspp1 promotes HSC cycling and induces p53-dependent apoptosis in cells with persistent DNA damage foci. Beyond these p53-dependent functions, Aspp1 attenuates HSC self-renewal and accumulation of DNA damage in p53-null HSCs. Consequently, concomitant loss of Aspp1 and p53 leads to the development of hematological malignancies, especially T-cell leukemia and lymphoma. Together, these data highlights coordination between Aspp1 and p53 in regulating HSC self-renewal and DNA damage tolerance, and suggest that HSCs possess specific mechanisms that prevent accumulation of mutations and malignant transformation. 8-week-old WT, Aspp1-/-, Mx1-Cre(+)p53flox/flox and Mx1-Cre(+)Aspp1-/-p53flox/flox mice were intraperitoneally administered with 400 μg pIpC five times every other day to obtain WT, Aspp1-/-, p53-/- and Aspp1-/-p53-/- bone marrow. 4 weeks after pIpC treatment, bone marrow lineage(-) Sca-1(+) cKit(+) cells were isolated. RNA was extracted and pooled from 3 independent mice per genotype. RNA samples were then amplified, labeled, and hybridized to independent arrays.
Project description:The MLL-PTD mutation is found in patients with MDS and AML, and not in other hematological malignancies. Previously, we showed that Mll-PTD knock-in heterozygous mice (MllPTD/WT mice) present with several MDS-associated features. However, these phenotypes are insufficient to constitute bona fide MDS. MllPTD/WT mice do not generate MDS or AML in primary or transplant recipient mice. This suggests that additional genetic and/or epigenetic defects are necessary for transformation to MDS or AML. In secondary AML and de novo AML, MLL-PTD mutation is significantly associated with mutations in RUNX1 and with the FLT3-ITD mutations. In fact, the combination of MLL-PTD with the FLT3-ITD allele leads to AML in mice. We combined the MLL-PTD with RUNX1 mutant proteins, in order to generate a new mouse model for MDS. We generated MllPTD/WT/Runx1Flox/Flox/Mx1-Cre mice to model loss-of-function RUNX1 mutations. To test the significance of HIF-1α in this model, we also generated MllPTD/WT/Runx1Flox/Flox/Hif-1αFlox/Flox/Mx1-Cre mice and genetically eliminated Hif-1α expression. We analyzed gene expression variations in the HSPCs comparing the MllPTD/WT/Runx1∆/∆ with or without HIF-1α abrogation.
Project description:The global change of the miRNA expression profile during atherosclerosis is due to the infiltration of different types of leukocytes into the arterial vessel wall in addition to disease-specific regulation in vascular cells. Monocyte-derived macrophage accumulation in the subintimal region is critical in the formation of atherosclerotic plaques. However, the role of Dicer, the key enzyme for miRNA biogenesis, during the development of atherosclerosis is currently unknown. To detect the effect of Dicer on miRNA expression in macrophages, the comparison of the miRNA expression profiles was performed in bone marrow-derived macrophages (BMDMs) from LysM-Cre/Dicerflox/flox/Apoe–/– and LysM-Cre/Dicerwt/wt/Apoe–/– mice. This screening combined with miRNA profiling in atherosclerotic aortas may help to identify the crucial miRNAs that play a role in the macrophage function during atherogenesis.