Mouse embryonic stem (ES) cells remain pluripotent in vitro when grown in presence of Leukaemia Inhibitory Factor (LIF). LIF starvation leads to apoptosis of some of the ES-derived differentiated cells, together with p38a MAP kinase activation. Apoptosis, but not morphological cell differentiation, is blocked by a p38 inhibitor, PD 169316. To further understand the mechanism of action of this compound, we have identified its specific targets by microarray studies. We report on the global expression profiles of genes expressed at three days upon LIF withdrawal (d3) compared to pluripotent cells and of genes whose expression is modulated at d3 under anti-apoptotic conditions. We showed that at d3 without LIF cells express, earlier than anticipated, specialized cell markers and that when the apoptotic process was impaired, expression of differentiation markers was altered. In addition, functional tests revealed properties of anti-apoptotic proteins not to alter cell pluripotency and a novel role for metallothionein 1 gene which prevents apoptosis of early differentiated cells.
Apoptosis and differentiation commitment: novel insights revealed by gene profiling studies in mouse embryonic stem cells.
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View SamplesMice used were B6/129 F2's, 3-5 weeks of age, either wild type or with both copies of the autoimmune regulator gene (aire, GenBank #AF079536) disrupted. Thymi from five of these mice of both sexes were removed and pooled. After collagenase/dispase digestion, density gradient fractionation, and fluorescent antibody staining, cells with the phenotype CD45-, G8.8+, CDR1int and B7.1hi were FACS-sorted and total RNA was made from them. RNA was twice-amplified using a T7 polymerase-based method.
Projection of an immunological self shadow within the thymus by the aire protein.
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Post-transplant molecularly defined Burkitt lymphomas are frequently MYC-negative and characterized by the 11q-gain/loss pattern.
Sex, Age, Treatment
View SamplesWe performed genomic and transcriptomic analysis of seven cases of molecular Burkitt lymphoma (mBL) developed in immunosuppressed patients who underwent solid organ transplantation. Interestingly, three cases (43%) were MYC-translocation-negative and revealed the 11q-gain/loss aberration recently identified in 3% of mBL developed in immunocompetent hosts.1 Based on array CGH data, minimal gain and loss regions of 11q (MGR/~4Mb and MLR/~13.5Mb, respectively) were defined and integrative genomic and transcriptomic analysis identified 35 differentially expressed genes, when compared with classic BL. All 16 MGR-dysregulated genes were upregulated, including cancer related USP2, CBL and PAFAH1B2. As expected, all 19 MGL-dysregulated genes were downregulated and two of them, TBRG1 and EI24, are potential tumor suppressor genes. Interestingly, the vast majority of dysregulated 11q23-q25 genes are involved in the MYC and TP53 networks. We hypothesize that the 11q-gain/loss aberration represents a molecular variant of t(8q24/MYC) and affects the same pathological pathways as the MYC oncogene.
Post-transplant molecularly defined Burkitt lymphomas are frequently MYC-negative and characterized by the 11q-gain/loss pattern.
Sex, Age, Treatment
View SamplesCell-autonomous circadian oscillations strongly influence tissue physiology and pathophysiology of peripheral organs. Recent in vivo findings in the heart demonstrate that the circadian clock controls oscillatory gene expression programs in the adult myocardium. However, whether in vitro human embryonic stem (ES) cell-derived cardiomyocytes can establish circadian rhythmicity is unknown. Here we report that while undifferentiated human ES cells do not possess a functional clock, oscillatory expression of known core clock genes emerges during directed cardiac differentiation, with robust rhythms in day 30 cardiomyocytes. Our data reveal a stress related oscillatory network of genes that underlies a time-dependent response to doxorubicin, a frequently used anti-cancer drug with cardiotoxic side effects. These results provide a set of oscillatory genes that is relevant to functional cardiac studies and that can be deployed to uncover the potential contribution of the clock to other processes such as cardiac regeneration. Overall design: Human embryonic stem cells (ES cells) were differentiated via a directed differentiation protocol in vitro towards cardiomyocytes for a period of 30 days. Cardiomyocytes were synchronized with dexamethasone and triplicate samples for RNA extraction and sequencing were taken every 4 hours for 48 hours in total. RNA was then extracted using TRIzol, barcoded and amplified following the CEL-Seq protocol.
Circadian networks in human embryonic stem cell-derived cardiomyocytes.
Specimen part, Subject
View SamplesT-cell/histiocyte rich B cell lymphoma (THRBL) and nodular lymphocyte predominant Hodgkin's lymphoma (NLPHL) share some morphological characteristics, including a prominent stromal reaction, but display a markedly different prognosis. To investigate the difference between the stromal reactions of these lymphomas at the molecular level, we performed microarray expression profiling on a series of THRBL and NLPHL cases.
T-cell/histiocyte-rich large B-cell lymphoma shows transcriptional features suggestive of a tolerogenic host immune response.
Sex, Specimen part
View SamplesIn this study we focussed on malignant post-transplant lymphomas.
Gene expression profiling reveals clear differences between EBV-positive and EBV-negative posttransplant lymphoproliferative disorders.
Specimen part
View SamplesANGPTL4 regulates plasma lipids, making it an attractive target for correcting dyslipidemia. However, ANGPTL4 inactivation in mice fed a high fat diet causes chylous ascites, an acute-phase response, and mesenteric lymphadenopathy. Here, we studied the role of ANGPTL4 in lipid uptake in macrophages and in the above-mentioned pathologies using Angptl4-hypomorphic and Angptl4-/- mice. Angptl4 expression in peritoneal and bone marrow-derived macrophages was highly induced by lipids. Recombinant ANGPTL4 decreased lipid uptake in macrophages, whereas deficiency of ANGPTL4 increased lipid uptake, upregulated lipid-induced genes, and increased respiration. ANGPTL4 deficiency did not alter LPL protein levels in macrophages. Angptl4-hypomorphic mice with partial expression of a truncated N-terminal ANGPTL4 exhibited reduced fasting plasma triglyceride, cholesterol, and non-esterified fatty acid levels, strongly resembling Angptl4-/- mice. However, during high fat feeding, Angptl4-hypomorphic mice showed markedly delayed and attenuated elevation in plasma serum amyloid A and much milder chylous ascites than Angptl4-/- mice, despite similar abundance of lipid-laden giant cells in mesenteric lymph nodes. In conclusion, ANGPTL4 deficiency increases lipid uptake and respiration in macrophages without affecting LPL protein levels. Compared with the absence of ANGPTL4, low levels of N-terminal ANGPTL4 mitigate the development of chylous ascites and an acute-phase response in mice.
Characterization of ANGPTL4 function in macrophages and adipocytes using <i>Angptl4</i>-knockout and <i>Angptl4</i>-hypomorphic mice.
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View SamplesEvaluation of transcripts from soybean seed tissue during seed fill for a pair of near-isogenic lines contrasting in seed protein and oil and carrying an introgression at the linkage group I protein QTL region. ****[PLEXdb(http://www.plexdb.org) has submitted this series at GEO on behalf of the original contributor, Yung-Tsi Bolon. The equivalent experiment is GM11 at PLEXdb.]
Complementary genetic and genomic approaches help characterize the linkage group I seed protein QTL in soybean.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
HILPDA Uncouples Lipid Droplet Accumulation in Adipose Tissue Macrophages from Inflammation and Metabolic Dysregulation.
Specimen part, Treatment
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