MED23, a subunit of the Mediator coactivator complex, is important for the expression of a subset of MAPK/ERK pathway-dependent target genes; however, the genes in this subset varies between cell types. MAPK/ERK pathway-dependent processes are essential for T-cell development and function, but whether MED23 has a role in this context is unknown. We generated Med23 conditional knockout mice and induced Med23 deletion in early T cell development using the lineage specific Lck-Cre transgene. While the total cell number and distribution of cell populations in the thymuses of Med23flox/flox;Lck-Cre mice were essentially normal, MED23 null T-cells failed to efficiently populate the peripheral lymphoid organs. MED23 null thymocytes displayed decreased expression of the MAPK/ERK-responsive genes Egr1, Egr2, as well as of the membrane glycoprotein Cd52 (CAMPATH-1). MED23 null CD4 single-positive thymocytes also showed decreased expression of KLF2 (LKLF), a T cell master regulatory transcription factor. Indeed, similarities between the phenotypes of mice lacking MED23 or KLF2 in T-cells suggest that KLF2 deficiency in MED23 null T-cells is one of their key defects. Mechanistic experiments using MED23 null MEFs further suggest that MED23 is required for full activity of the MAPK-responsive transcription factor MEF2, which has previously been shown to mediate Klf2 expression. In summary, our data indicate that MED23 has critical roles in enabling T-cells to populate the peripheral lymphoid organs, possibly by potentiating MEF2-dependent expression of the T-cell transcription factor KLF2.
T-cells null for the MED23 subunit of mediator express decreased levels of KLF2 and inefficiently populate the peripheral lymphoid organs.
Sex, Specimen part
View SamplesPurpose: The goals of this study are to understand ZIKV induced immune responses in the developing brain at genome-wide level. Methods: Total RNA was isolated from E17.5 mouse brains after viral infection at E14.5. After genomic DNA and ribosomal RNA removal, fractionated RNA were subjected to strand-specific library preparation using NEBNext Ultra RNA Library Prep Kit. Sequencing was performed on Nextseq500 (Illumina). The sequencing reads that passed quality filters were analyzed with TopHat followed by Cufflinks. Results: After performed Gene Ontology analyses with RNA-seq data, our results revealed a set of genes that are associated with the immune response and apoptosis pathways. Gene Set Enrichment Analysis (GSEA) further show significant enrichments on both the immune system response and apoptosis pathways. Some of these results were also verified with qRT-PCR. Conclusions: Our results suggest that ZIKV infection triggers an aggressive immune response, which has the potential to cause exacerbation of brain damage by enhancing neuronal death and generating vascular abnormalities. Our discovery of massive neuronal death, leaky blood-brain-barrier (BBB), and astrogliosis in ZIKV infected brains is the first study to suggest that ZIKA causes extensive brain damage. Overall design: RNA-seq of C56BL/6 mouse E17.5 brain with or without Zika virus infection.
Zika virus infection disrupts neurovascular development and results in postnatal microcephaly with brain damage.
Specimen part, Subject
View SamplesTF1a AML cell line was selected for in vitro modelling of dormancy in AML. TF1-a were subjected to AML-niche-mimicking in vitro conditioning by culture with TGFB1 and the mTOR inhibitor rapamycin. Also TF1a cells were in vitro cultured with prolonged sublethal doses of Etoposide.
A molecular signature of dormancy in CD34<sup>+</sup>CD38<sup>-</sup> acute myeloid leukaemia cells.
Specimen part
View SamplesThe mammalian liver, the largest solid organ in the body, accomplishes multiple critical roles necessary to preserve homeostasis. Human liver diseases are debilitating, costly and very often result in death. Uncovering developmental mechanisms that establish the complex architecture of the liver or generate the cellular diversity of this organ is necessary to develop more adequate methods to prevent, diagnose and cure liver diseases. This study investigated the role of the homeobox gene Prox1 during mouse hepatogenesis.
Prox1 ablation in hepatic progenitors causes defective hepatocyte specification and increases biliary cell commitment.
Specimen part
View SamplesT-regulatory (Treg) cells are important to immune homeostasis, and Treg cell deficiency or dysfunction leads to autoimmune disease. An histone/protein acetyltransferase (HAT), p300, was recently found important for Treg function and stability, but further insights into the mechanisms by which p300 or other HATs affect Treg biology are needed. Here we show that CBP, a p300 paralog, is also important in controlling Treg function and stability. Thus, while mice with Treg-specific deletion of CBP or p300 developed minimal autoimmune disease, the combined deletion of CBP and p300 led to fatal autoimmunity by 3-4 weeks of age. The effects of CBP and p300 deletion on Treg development are dose-dependent, and involve multiple mechanisms. CBP and p300 cooperate with several key Treg transcription factors that act on the Foxp3 promoter to promote Foxp3 production. CBP and p300 also act on the Foxp3 CNS2 region to maintain Treg stability in inflammatory environments by regulating pCREB function and GATA3 expression, respectively. Lastly, CBP and p300 regulate the epigenetic status and function of Foxp3. Our findings provide insights into how HATs orchestrate multiple aspects of Treg development and function, and identify overlapping but also discrete activities for p300 and CBP in control of Treg cells.
Two histone/protein acetyltransferases, CBP and p300, are indispensable for Foxp3+ T-regulatory cell development and function.
No sample metadata fields
View SamplesInactivating mutations of the gene encoding for the CREBBP acetyltransferase are highly frequent in diffuse large B cell lymphoma (DLBCL, 30% of cases) and follicular lymphoma (FL, 60% of cases), the two most common cancers derived from thegerminal-center (GC). However, the role of CREBBP inactivation in lymphomagenesisremains unclear. Using functional epigenomics and mouse genetics, here we definethe program modulated by CREBBP in primary human GC B cells and show thatCREBBP regulates enhancer/super-enhancer networks, with specific roles in GC/post-GC cell fate decisions. Conditional GC-specific deletion of Crebbp in the mouseperturbs the expression of a limited set of genes involved in the regulation of signaltransduction (BCR, TLR and CD40), lineage specification (NF-B and BCL6) andterminal B cell differentiation (PRDM1, IRF4). Consistently, Crebbp-deficient B cellsexhibit proliferative advantage and show impaired plasma cell differentiation. WhileGC-specific loss of Crebbp was not sufficient to initiate malignant transformation,compound Crebbp-haploinsufficient/BCL2-transgenic mice, mimicking the genetics ofFL and DLBCL, display an increased incidence of clonal lymphoid malignanciesrecapitulating the features of the human diseases. These findings establish CREBBPas a haploinsufficient tumor suppressor gene in GC B cells and provide insights intothe mechanisms and targes by which loss of CREBBP contributes to lymphomagenesis.
The CREBBP Acetyltransferase Is a Haploinsufficient Tumor Suppressor in B-cell Lymphoma.
Sex, Specimen part
View SamplesFoxp3+ T-regulatory (Treg) cells maintain immune homeostasis and limit autoimmunity, but can also curtail host responses to cancers. Tregs are therefore promising targets to enhance anti-tumor immunity. Histone/protein acetyltransferases (HATs) promote chromatin accessibility, gene transcription and the function of multiple transcription factors and non-histone proteins. We found that conditional deletion or pharmacologic inhibition of one specific HAT, p300, in Foxp3+ Tregs, increased TCR-induced apoptosis in Tregs, impaired Treg suppressive function and iTreg peripheral conversion, and limited tumor growth in immunocompetent, but not in immunodeficient, hosts. Our data demonstrate that p300 is important for Foxp3+ Treg function and homeostasis in vivo and in vitro, and identify a novel mechanism to diminish Treg function without overtly impairing effector Tcell responses or inducing autoimmunity. Collectively, these data suggest a new approach for cancer immunotherapy.
Inhibition of p300 impairs Foxp3⁺ T regulatory cell function and promotes antitumor immunity.
Specimen part
View SamplesThe bifunctional enzyme 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase-4 (PFKFB4) controls metabolic flux through allosteric regulation of glycolysis. Here we show that p53 regulates the expression of PFKFB4 and that p53-deficient cancer cells are highly dependent on the function of this enzyme. We found that p53 down-regulates PFKFB4 expression by binding to its promoter and mediating transcriptional repression via histone deacetylases. Depletion of PFKFB4 from p53 deficient cancer cells increased levels of the allosteric regulator fructose 2,6-bisphophate, leading to increased glycolytic activity but decreased routing of metabolites through the oxidative arm of the pentose phosphate pathway. PFKFB4 was also required to support the synthesis and regeneration of nicotinamide adenine dinucleotide phosphate (NADPH) in p53 deficient cancer cells. Moreover, depletion of PFKFB4 attenuated cellular biosynthetic activity and resulted in the accumulation of reactive oxygen species and cell death in the absence of p53. Finally, silencing of PFKFB4 induced apoptosis in p53 deficient cancer cells in vivo and interfered with tumour growth. These results demonstrate that PFKFB4 is essential to support anabolic metabolism in p53-deficient cancer cells and suggest that inhibition of PFKFB4 could be an effective strategy for cancer treatment. Overall design: Gene expression changes in HCT116 p53+/+ and p53-/- xenograft tumours after PFKFB4 silencing
6-Phosphofructo-2-kinase/fructose-2,6-biphosphatase 4 is essential for p53-null cancer cells.
Specimen part, Cell line, Subject
View SamplesThe ADAR RNA editing enzymes deaminate adenosine bases to inosines in cellular RNAs, recoding open reading frames. Human ADAR1 mutations cause Aicardi-Goutieres Syndrome (AGS) and Adar1 mutant mice showing an aberrant interferon response and death by embryonic day E12.5 model the human disease. Searches have not identified key ADAR1 RNA editing sites recoding immune/haematopoietic proteins but editing is widespread in Alu sequences. We show that Adar1 embryonic lethality is rescued in Adar1; Mavs double mutant mice in which general antiviral responses to cytoplasmic dsRNA are prevented. We propose that inosine bases are epigenetic marks identifying cellular RNA as innate immune ÒselfÓ. Consistent with this idea we show that an editing-active cytoplasmic ADAR is required to prevent aberrant immune responses in Adar1 mutant mouse embryo fibroblasts. No dramatic increase in repetitive transcripts is observed. AGS mutations in ADAR1 affect editing by the interferon-inducible cytoplasmic ADAR1 isoform. Overall design: RNA-seq expression profiling in Adar1 and Adar1/Mavs knockout mice embryos.
The RNA-editing enzyme ADAR1 controls innate immune responses to RNA.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Nuclear ARRB1 induces pseudohypoxia and cellular metabolism reprogramming in prostate cancer.
Specimen part, Cell line
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