TET proteins oxidize 5-methylcytosine to 5-hydroxymethylcytosine and further oxidation products in DNA. Here we report that simultaneous deletion of Tet2 and Tet3 in mouse double-positive thymocytes resulted in dysregulated development and proliferation of invariant natural killer T (iNKT) cells. Tet2-Tet3-double-deficient (DKO) iNKT cells displayed pronounced skewing towards the NKT17 lineage, with increased DNA methylation and impaired expression of genes encoding the key lineage-specifying factors T-bet and ThPOK. Transfer of purified Tet2-Tet3 DKO iNKT cells into immunocompetent recipient mice resulted in uncontrolled expansion dependent on the nonclassical MHC protein CD1d, which presents lipid antigens to iNKT cells. Our data indicate that TET proteins regulate iNKT cell fate by ensuring proper development and maturation and suppressing aberrant T cell antigen receptor (TCR)-mediated proliferation. Overall design: DKO vs. wild type
TET proteins regulate the lineage specification and TCR-mediated expansion of iNKT cells.
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View SamplesDioxygenases of the TET family impact genome functions by converting 5-methylcytosine in DNA to 5-hydroxymethylcytosine, but the individual contribution of the three family members to differentiation and function of myeloid cells is still incompletely understood. Using cells with a deletion in the Tet2 gene, we show that TET2 contributes to the regulation of mast cell differentiation, proliferation and effector functions. The differentiation defect observed in absence of TET2 could be however completely rescued or further exacerbated by modulating TET3 activity, and it was primarily linked to dysregulated expression of the C/EBP family of transcription factors. In contrast, hyper-proliferation induced by the lack of TET2 could not be modified by TET3. Together, our data indicate the existence of both overlapping and unique roles of individual TET proteins in regulating myeloid cell gene expression, proliferation and function. Overall design: Total mRNA of FACS-sorted Kit+ FceRIa+ populations of primary bone marrow-derived mast cells (BMMCs) from Tet2-/- and Tet2+/+ animals was extracted and subjected to multiparallel sequencing.
TET2 Regulates Mast Cell Differentiation and Proliferation through Catalytic and Non-catalytic Activities.
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View SamplesBromodomain-containing proteins bind acetylated lysine residues on histone tails and are involved in the recruitment of additional factors that mediate histone modifications and enable transcription. A compound, I-BET-762, that inhibits binding of an acetylated histone peptide to BRD4 and other proteins of the BET (bromodomain and extra-terminal domain) family, was previously shown to suppress the production of pro-inflammatory proteins by macrophages and block acute inflammation in mice. Here we investigate the effect of I-BET-762 on T cell function. We show that treatment of nave CD4+ T cells with I-BET-762 during early differentiation modulates subsequent cytokine production, and inhibits the ability of Th1-skewed cells to induce autoimmune pathogenesis in a model of experimental autoimmune encephalomyelitis (EAE) in vivo. The suppressive effects of I-BET-762 on T-cell mediated inflammation were not due to inhibition of expression of the pro-inflammatory cytokines, IFN-. or IL-17, but correlated with the ability to suppress GM-CSF production from CNS-infiltrating T cells, resulting in decreased recruitment of macrophages and granulocytes. The effects of I-BET-762 were distinct from those of the fumarate ester, dimethyl fumarate (DMF), a candidate drug for treatment of multiple sclerosis (MS). Our data suggest that I-BET and DMF could have complementary roles in the treatment of MS, and provide a strong rationale for inhibitors of BET-family proteins in the treatment of autoimmune diseases, based on their dual ability to suppress granulocyte and macrophage recruitment by T cells as well as production of pro-inflammatory proteins by macrophages.
Selective inhibition of CD4+ T-cell cytokine production and autoimmunity by BET protein and c-Myc inhibitors.
Specimen part
View SamplesIn the present study, we employed Affymetrix Staphylococcus aureus GeneChip arrays to investigate the dynamics of global gene expression profiles during the cellular response of Staphylococcus aureus to Ortho-Phenylphenol, which involved initial growth inhibition and metabolism.
Microarray analysis of toxicogenomic effects of ortho-phenylphenol in Staphylococcus aureus.
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View SamplesIn the present study, we employed Affymetrix Staphylococcus aureus GeneChip arrays to investigate the dynamics of global gene expression profiles during the cellular response of Staphylococcus aureus to triclosan, which involved initial growth inhibition and metabolism.
Microarray analysis of toxicogenomic effects of triclosan on Staphylococcus aureus.
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View SamplesIn the present study, we employed Affymetrix Pseudomonas aeruginosa GeneChip arrays to investigate the dynamics of global gene expression profiles during the cellular response of Pseudomonas aeruginosa to ortho-phenylphenol, which involved initial growth inhibition and metabolism.
Toxicogenomic response of Pseudomonas aeruginosa to ortho-phenylphenol.
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View SamplesIn the present study, we employed Affymetrix Pseudomonas aeruginosa GeneChip arrays to investigate the dynamics of global gene expression profiles during the cellular response of Pseudomonas aeruginosa to Chlorhexidine diacetate, which involved initial growth inhibition and metabolism.
Global transcriptomic response of Pseudomonas aeruginosa to chlorhexidine diacetate.
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View SamplesThe liver circadian clock is reprogrammed by nutritional challenge through the rewiring of specific transcriptional pathways. As the gut microbiota is tightly connected to host metabolism, whose coordination is governed by the circadian clock, we explored whether gut microbes influence circadian homeostasis and how they distally control the peripheral clock in the liver. Using fecal transplant procedures we reveal that, in response to high fat diet, the gut microbiota drives PPAR-mediated activation of newly oscillatory transcriptional programs in the liver. Moreover, antibiotics treatment prevents PPAR-driven transcription in the liver, underscoring the essential role of gut microbes in clock reprogramming and hepatic circadian homeostasis. Thus, a specific molecular signature characterizes the influence of the gut microbiome in the liver, leading to the transcriptional rewiring of hepatic metabolism.
Gut microbiota directs PPARγ-driven reprogramming of the liver circadian clock by nutritional challenge.
Specimen part
View SamplesThe goal of this study was to compare the transcriptional profile (RNA-seq) of imbibed Arabidopsis thaliana Columbia-0 ecotype seeds that were treated with a 20 min red or far red pulse. The red-light pulse induces germination. Overall design: Col-0 seeds were sown in clear plastic boxes, each containing 10 mL of 0.8 % (w/v) agar in demineralized water. To establish a minimum and equal photo-equilibrium, seeds were imbibed for 2 hours in darkness and then irradiated for 20 min with a saturated far-red pulse (FRp, calculated Pfr/P= 0.03, 42 µmol.m-2.s-1) in order to minimize the quantities of Pfr formed during their development in the mother plant. Seeds were then stratified at 5 °C in darkness for 3 days, prior to the 20 minutes with a saturated red pulse (Rp, calculated Pfr/P= 0.87, 0.05 µmol.m-2.s-1) or FRp. Three biological replicates of each condition were collected 12 hours after the corresponding R and FR light pulses.
Alternative Splicing Regulation During Light-Induced Germination of <i>Arabidopsis thaliana</i> Seeds.
Subject
View SamplesThe circadian clock orchestrates rhythms in physiology and behavior, allowing the organism to adapt to daily environmental changes. Recently, efforts have been made to unravel the connection between the circadian clock and metabolism and to understand how the peripheral clock in different organs coordinates circadian responses to maintain metabolic homeostasis. It is becoming clear that diet can influence diurnal rhythms, however, the molecular mechanisms responsible for alterations in daily oscillations and how tissue-specific clocks interpret a nutritional challenge are not well understood. Here, we reveal tissue-specific circadian plasticity in response to a ketogenic diet (KD) in both the liver and intestine and a remarkable deviation within these two tissues following subsequent carbohydrate supplementation. KD caused a dramatic change in the circadian transcriptome in both liver and intestine in a tissue-specific fashion. In particular, both the amplitude of clock genes as well as specific BMAL1 recruitment was profoundly altered by KD while the intestinal clock was devoid of such plasticity. While PPARG nuclear accumulation was circadian in both tissues, it showed substantial phase specificity as did downstream targets. Finally, the gut and liver clocks had distinct responses to carbohydrate supplementation to KD composition, suggesting a higher plasticity in the ileum whose gene expression was almost restored to control baseline. For the first time our results demonstrate how nutrients modulate clock function in a tissue-specific manner, suggesting that a food stress arouses unique circadian molecular signatures in distinct peripheral tissues.
Distinct Circadian Signatures in Liver and Gut Clocks Revealed by Ketogenic Diet.
Specimen part
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