The genetic programs that promote retention of self-renewing leukemia stem cells (LSCs) at the apex of cellular hierarchies in acute myeloid leukemia (AML) are not known. In a mouse model of human AML, LSCs exhibit variable frequencies that correlate with the initiating MLL oncogene and are maintained in a self-renewing state by a transcriptional sub-program more akin to that of embryonic stem cells (ESCs) than adult stem cells. The transcription/chromatin regulatory factors Myb, Hmgb3 and Cbx5 are critical components of the program and suffice for Hoxa/Meis-independent immortalization of myeloid progenitors when co-expressed, establishing the cooperative and essential role of an ESC-like LSC maintenance program ancillary to the leukemia initiating MLL/Hox/Meis program. Enriched expression of LSC maintenance and ESC-like program genes in normal myeloid progenitors and poor prognosis human malignancies links the frequency of aberrantly self-renewing progenitor-like cancer stem cells to prognosis in human cancer.
Hierarchical maintenance of MLL myeloid leukemia stem cells employs a transcriptional program shared with embryonic rather than adult stem cells.
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View SamplesNormal myeloid lineage cell populations (C57BL/6 mice, aged 4-10 weeks, male or female) with three distinct immunophenotypes were prospectively isolated and characterized. In preparation for FACS sorting, bone marrow cells were separated into c-kit+ and c-kit- fractions using an AutoMACS device. C-kit+ cells were further fractionated based on Gr1 and Mac1 expression, and absence of lineage antigen expression (B220, TER119, CD3, CD4, CD8 and IL7R), by cell sorting. C-kit+ Gr1+ Mac1lo/- and c-kit+ Gr1+ Mac1+ displayed cytologic features of undifferentiated hematopoietic cells or myeloblasts, whereas c-kit- Gr1+ Mac1+ cells were mature neutrophils.
Hierarchical maintenance of MLL myeloid leukemia stem cells employs a transcriptional program shared with embryonic rather than adult stem cells.
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View SamplesLeukemia cells from mice with MLL-AF10 AML were fractionated into separate sub-populations on the basis of c-kit expression, which correlates with MLL LSC frequency (Somervaille and Cleary, 2006). The sorted AML sub-populations exhibited substantial differences in their frequencies of AML CFCs/LSCs (mean 14-fold) and morphologic features, consistent with a leukemia cell hierarchy with maturation through to terminally differentiated neutrophils.
Hierarchical maintenance of MLL myeloid leukemia stem cells employs a transcriptional program shared with embryonic rather than adult stem cells.
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View SamplesIKK kinase is essential for the B cell maturation and secondary lymphoid organ development. In the current study, we evaluated the role of IKK in the marginal zone and follicular B lymphocyte development by genetically deleting IKK from the B cell lineage using CD19-Cre mice. The loss of IKK did not affect the normal development of early B cell progenitors. However, a significant decline was observed in the percentage of immature B lymphocytes, mature marginal zone and follicular B cells along with a severe disruption of splenic marginal and follicular B cell zones. A gene expression analysis performed on the RNA extracted from the newly formed B cells (B220+IgMhi) revealed that IKK deficiency produces significant changes in the expression of genes involved in MZ and FO B lymphocyte survival, homing and migration. And several among those genes identified belong to G protein family. Specifically, we validated the upregulated expression of regulator of G protein signaling 13 (RGS13), which is a GTPase activating protein (GAP) that negatively regulates G protein signaling and impede B cell migration. Likewise, promigratory B lymphocyte receptor, the sphingosine-1-phosphate receptor 3 (SIPR3) that couple to Gi showed significantly reduced expression. In addition, an in silico analysis of gene product interactions revealed NF-B signaling pathways to be a major gene regulating networks perturbed with IKK deletion. Taken together, this study reveals IKKNF-B and G protein signaling axis to be central for the MZ and FO B cells survival, maintenance, homing and migration.
IKKα deficiency disrupts the development of marginal zone and follicular B cells.
Specimen part
View SamplesTranscriptional profiling of the zebrafish embryonic host response to a systemic bacterial infection with Salmonella typhimurium (strain SL1027); comparison between traf6 knock-down and control morpholino treated embryos. Overall design: All infection experiments were performed using mixed egg clutches of ABxTL strain zebrafish. Embryos injected with traf6 morpholino or a 5bp mismatch control morpholino were staged at 27 hours post fertilization (hpf) by morphological criteria and approximately 250 cfu of DsRed expressing Salmonella bacteria were injected into the caudal vein close to the urogenital opening. As a control an equal volume of PBS was likewise injected. Pools of 20-40 infected and control embryos were collected 8 hours post infection (hpi). The whole procedure was preformed in triplicate on separate days. Total RNA of the biological triplicates was pooled using equal amounts of RNA prior to RNAseq library preparation.
Transcriptome analysis of Traf6 function in the innate immune response of zebrafish embryos.
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View SamplesThis SuperSeries is composed of the SubSeries listed below.
A tissue-specific landscape of sense/antisense transcription in the mouse intestine.
Specimen part
View SamplesGenome wide expression profiling to determine the overlap of Affymetrix-signals with SOLID sequencing
A tissue-specific landscape of sense/antisense transcription in the mouse intestine.
Specimen part
View SamplesAims: We investigate sex differences and the role of oestrogen receptor beta (ERbeta) in a mouse model of pressure overload-induced myocardial hypertrophy. Methods and results: We performed transverse aortic constriction (TAC) or sham surgery in male and female wild-type (WT) and ERbeta knockout (ERbeta-/-) C57Bl6 mice. All mice were characterised by echocardiography and haemodynamic measurements and were sacrificed nine weeks after surgery. Left ventricular (LV) samples were analysed by microarray profiling, real-time RT-PCR and histology. After nine weeks, WT males showed more hypertrophy and heart failure signs than WT females. Notably, WT females developed a concentric form of hypertrophy, while males developed eccentric hypertrophy. These sex differences were abolished in ERbeta-/- mice. ERbeta deletion augmented the TAC-induced increase in cardiomyocyte diameter in both sexes. Gene expression profiling revealed that male WT hearts had a stronger induction of matrix-related genes and a stronger repression of mitochondrial genes than female hearts. ERbeta-/- mice exhibited a different transcriptome. Induction of pro-apoptotic genes after TAC occurred in ERbeta-/- mice of both sexes with a stronger expression in ERbeta-/- males. Histological analysis revealed, that cardiac fibrosis was more pronounced in male WT TAC than in female mice. This was abolished in ERbeta-/- mice. Apoptosis was significantly induced in both sexes of ERbeta-/- TAC mice, but it was most prominent in males. Conclusion: Female sex offers protection against ventricular chamber dilation in the TAC model. Both the female sex and ERbeta attenuate the development of fibrosis and apoptosis; thus slowing the progression to heart failure.
Female sex and estrogen receptor-beta attenuate cardiac remodeling and apoptosis in pressure overload.
Sex, Age, Specimen part
View SamplesGinkgo biloba leaf extract (GBE) has been used for centuries in traditional Chinese medicine and today is used as an herbal supplement for various indications such as improving neural function, anti-oxidant and anti-cancer effects. As part of the herbal supplement industry, these compounds are largely unregulated, and may be consumed in large concentrations over extended periods of time. This is of particular concern, because the long-term effects in terms of toxicity and carcinogenicity data is lacking for many herbal products, including GBE. The 2-year B6C3F1 mouse carcinogenicity bioassay indicated a marked dose-related increase in hepatocellular carcinoma (HCC) development associated with exposure to GBE. We have shown that the mechanism of this increase in tumorigenesis is related to a marked increase in the incidence of -catenin mutation, and report a novel mechanism of constitutive -catenin activation through post-translational modification leading to constitutive Wnt signaling and unregulated growth signaling and oncogenesis. Furthermore, using global gene expression profiling, we show that GBE-induced HCC exhibit overrepresentation of gene categories associated with human cancer and HCC signaling including upregulation of relevant oncogenes and suppression of critical tumor suppressor genes, as well as chronic oxidative stress, a known inducer of calpain-mediated degradation and promoter of hepatocarcinogenesis in humans. These data provide a molecular mechanism to GBE-induced HCC in B6C3F1 mice that is relevant to human cancer, and provides relevant molecular data that will provide the groundwork for further risk assessment of unregulated compounds, including herbal supplements.
Hepatocellular carcinomas in B6C3F1 mice treated with Ginkgo biloba extract for two years differ from spontaneous liver tumors in cancer gene mutations and genomic pathways.
Specimen part
View SamplesSTAT3 is a pleiotropic transcription factor with important functions in cytokine signalling in a variety of tissues. However, the role of STAT3 in the intestinal epithelium is not well understood. Here we demonstrate that development of colonic inflammation is associated with the induction of STAT3 activity in intestinal epithelial cells (IEC). Studies in genetically engineered mice showed that epithelial STAT3 activation in DSS colitis is dependent on IL-22 rather than IL-6. IL-22 was secreted by colonic CD11c+ cells in response to Toll-like receptor stimulation. Conditional knockout mice with an IEC specific deletion of STAT3 activity were highly susceptible to experimental colitis, indicating that epithelial STAT3 regulates gut homeostasis. STAT3IEC-KO mice, upon induction of colitis, showed a striking defect of epithelial restitution. Gene chip analysis indicated that STAT3 regulates the cellular stress response, apoptosis and pathways associated with wound healing in IEC. Consistently, both IL-22 and epithelial STAT3 were found to be important in wound-healing experiments in vivo. In summary, our data suggest that intestinal epithelial STAT3 activation regulates immune homeostasis in the gut by promoting IL-22-dependent mucosal wound healing.
STAT3 links IL-22 signaling in intestinal epithelial cells to mucosal wound healing.
Specimen part
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