Ontology highlight
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PROVIDER: PRJNA450113 | ENA |
REPOSITORIES: ENA
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Project description:NFKB is a family of transcription factors (TF), which are master regulators of the innate immune system. It is activated downstream of pathogen recognition receptors after ligand binding and regulates the expression of antimicrobials, cytokines and chemokines, thus helping to fight infections as well as recruiting the adaptive immune system. Although NFKB responds to a wide variety of signals, the processes in which stimulus-specificity is attained are still unclear. Here, we characterized the response of one of the NFKB members, RELA, to five stimuli mimicking infection in nasopharyngeal epithelial cells. When comparing RELA genome-wide binding sites , we detected most of them to be overlapping among the different stimulations. Yet, we distinguished a minority of stimulus-specific RELA binding sites. Interestingly, some of these seemed to have a biological effect as they correlated with corresponding gene expression. Specifically, the response to Poly I:C mimicking viral dsRNA gave a distinct RELA profile binding the vicinity of antiviral genes. This group of binding sites was also enriched in Interferon Regulatory Factor motifs indicating that the interaction with more specialized TFs could contribute to stimulus-specific RELA activity. Furthermore, motif analysis revealed differences in the sequence of the NFKB motifs between certain stimulus-specific sets of peaks suggesting preferences for particular NFKB dimers in response to defined signals.
2018-01-30 | GSE91018 | GEO
Project description:NFKB is a family of transcription factors (TF), which are master regulators of the innate immune system. It is activated downstream of pathogen recognition receptors after ligand binding and regulates the expression of antimicrobials, cytokines and chemokines, thus helping to fight infections as well as recruiting the adaptive immune system. Although NFKB responds to a wide variety of signals, the processes in which stimulus-specificity is attained are still unclear. We characterized the response of one of the NFKB members, RELA, to five stimuli mimicking infection in nasopharyngeal epithelial cells. We wanted to investigate gene expression in response to these stimuli as well, in order to relate RELA binding to differences to expression regulation. Although most RELA binding sites where common among stimulation, we distinguished a minority of stimulus-specific RELA binding sites. Interestingly, some of these seemed to have a biological effect as they correlated with corresponding gene expression. Especially, the response to Poly I:C mimicking viral dsRNA gave a distinct RELA profile binding the vicinity of antiviral genes. Some of which were overexpressed under Poly I:C stimulation specifically.
2018-01-30 | GSE91019 | GEO
Project description:Epigenetic modifications play crucial roles on establishment of tissue-specific transcription profiles and cellular characteristics. Direct conversions of fibroblasts into differentiated tissue cells by over-expression of critical transcription factors have been reported, but the epigenetic mechanisms underlying these conversions are still not fully understood. In addition, conversion of somatic cells into germ cells has not yet been achieved. To understand epigenetic mechanisms that underlie germ cell characteristics, we attempted to use defined epigenetic factors to directly convert mouse embryonic fibroblasts (MEFs) into germ cells. Here, we successfully induced germ cell-specific genes by inhibiting repressive epigenetic modifications via RNAi or small-molecule compounds. Under these conditions, some tissue-specific genes and stimulus-inducible genes were also induced. Meanwhile, the treatments did not result in genome-wide transcriptional activation. These results suggested that a permissive epigenetic environment resulted in selective de-repression of stimulus- and differentiation-inducible genes including germ cell-specific genes in MEFs.
2016-09-09 | GSE86005 | GEO
Project description:We here identified that the trimeric spike protein of SARS-CoV-2 could bind to TLR4 directly and robustly activate downstream signaling in monocytes and neutrophils. Moreover, specific TLR4 or NFKB inhibitor, or knockout of MyD88 could significantly block IL-1B induction by spike protein. We thus reveal that spike protein of SARS-CoV-2 functions as a potent stimulus causing TLR4 activation and sepsis related abnormal responses.
2021-02-25 | GSE167480 | GEO
Project description:According to current models, transcription factors (TFs) activated by extracellular stimuli operate in the context of a pre-established enhancer repertoire induced and maintained by lineage-specific TFs. Here, we uncovered the existence of latent enhancers, defined as regions of the genome that in terminally differentiated cells are poorly accessible and lack the histone marks characteristic of enhancers, but readily acquire these features in response to extracellular cues. Stimulation of resting macrophages caused simultaneous binding of stimulus-activated TFs and lineage-determining TFs to these regions, enabling deposition of enhancer-specific features. Once unveiled, these enhancers did not return to a latent state even when stimulation ceased; instead, they persisted and mediated a faster and stronger response upon restimulation. We suggest that stimulus-specific expansion of the available cis-regulatory repertoire provides an epigenomic memory of the exposure to environmental agents. Formaldehyde-Assisted Isolation Of Regulatory Elements (FAIRE) followed by multiparallel sequencing was performed in untreated murine bone marrow-derived macrophages.
2013-01-17 | E-GEOD-41677 | biostudies-arrayexpress
Project description:Reactive oxygen species (ROS) induced by ultraviolet B (UVB) cause DNA damage such as 8-oxoguanine (8-oxoG) in mouse skin, with long-term exposure leading skin tumor development. We previously reported that Ogg1 knockout mice, with defective repair enzyme for 8-oxoG oxidatively damaged DNA, showed greater up-regulation of inflammatory response genes and Versican, which encodes a large extracellular matrix proteoglycan, than their wild-type counterparts. Here, we focused on inflammatory response genes associated with Versican up-regulation after UVB exposure, using Ogg1 knockout mouse embryonic fibroblasts (MEFs). Gene profiling among inflammatory response-associated genes in MEFs treated with UVB showed that Cxcl1, a CXC chemokine, was most significantly up-regulated in Ogg1(-/-) MEFs, concomitant with the up-regulation of Versican. We found that Versican targeted siRNA directly regulated Cxcl1, and vice versa, in which the system of up-regulation for these two key genes were controlled by PI3kinase-NFkB activation signaling rather than conventional UV-induced p38 mitogen-activated protein kinase. Furthermore, for the initial process of differentiating inflammatory response between Ogg1(-/-) and Ogg1(+/+), we found that down-regulation of p53 along with anti-apoptotic signal was a key event in Ogg1(-/-).The results of the present study suggest suppression of skin tumor development involving UVB/ROS-induced 8-oxoG formation by targeting genes and signaling pathways.
2016-04-25 | GSE80362 | GEO
Project description:Developmental signals are known to modulate inflammation. How ever, the mechanistic insight that links developmental and inflammatory signaling remains elusive. In the current study, we identifya critical role of NF-kB system in mediating stimulus specific crosstalk that allows developmental LTbR signals to sustain inflammatory TLR4 induced RelA/NF-kB response and gene expression. LTbR activated non-canonical signaling targets canonical TLR4 induced, nfkb2 encoded p100 not only to deplete inhibitory IkBd/(p100)2, but also to supplement RelA:p52/NF-kB dimers. Robust crosstalk in the gut epithelial cells are important, as crosstalk-defective nfkb2-/- mice succumbed to gut infection by Citrobacter rodentium due to hypo-inflammatory responses. Finally, we present evidence for a crosstalk motif that integrates tissue microenvironment derived developmental cues to ameliorate the pathogen response. Total RNA from WT early passage MEFs stimulated with ligands LPS, LTbR and LPS+LTbR for 24hrs were analyzed for global gene expression levels
2015-05-01 | E-GEOD-62301 | biostudies-arrayexpress
Project description:The epigenome defines the cell type, but also possesses plasticity to tune gene expression in the context of extracellular cues. This tuning is evident in immune sentinel cells such as macrophages, which respond to pathogens and cytokines with phenotypic shifts driven by epigenomic reprogramming. Recent studies indicate that this reprogramming arises from the activity of transcription factors including nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB). NFκB binds not only to available enhancers but may also produce de novo enhancers in previously silent areas of the genome. Here, we show that NFκB reprograms the macrophage epigenome in a stimulus-specific manner, in response only to a subset of pathogen-derived stimuli. The basis for these surprising differences lies in the stimulus-specific temporal dynamics of NFκB activity. In response to different stimuli, NFκB enters the nucleus with variable speed, amplitude, and duration, and may oscillate between the nucleus and cytoplasm. These dynamical features combine to specify the identity and dose of a given stimulus. We demonstrate through live cell imaging, mathematical modeling, and genetic perturbations that NFκB promotes open chromatin and formation of de novo enhancers most strongly when its dynamics are non-oscillatory. These de novo enhancers result in the activation of additional response genes. We propose a mechanistic paradigm in which the temporal dynamics of transcription factors are a key determinant of their capacity to control epigenomic reprogramming, thus enabling the formation of stimulus-specific memory in innate immune sentinel cells.
2021-01-01 | GSE146068 | GEO
Project description:We explored the combinatorial interactions between p53, estrogen receptors and NFkB using the breast adenocarcinoma-derived MCF7 cells. Recently, we have established that p53 can modulate transcription also through non-canonical response elements (REs), consisting of half-sites and ¾ sites. In particular, we identified a half-site p53 response element in the promoter of FLT1/VEGFR-I gene that was required but not sufficient for the p53 responsiveness of the promoter. The transcriptional control required also estrogen receptor (ER) half-sites (EREs) located in close proximity to the p53 RE. Further studies led us to establish that p53-mediated transcription from the FLT1 half site RE is dependent on ER binding at the EREs and strongly influenced by the level of ER proteins, and the specific nature of the p53-inducing stress as well as ER ligand. In another study we found an enrichment of NFkB REs nearby p53 REs in p53 target genes, suggesting an additional mode of functional interactions between these two transcription factors. To identify at a genome scale the transcriptional network that selectively responds to the concomitant activation of p53, ER and/or NFkB, we measured gene expression upon treatment with specific chemotherapeutic agents combined with 17-β estradiol (E2) and/or the inflammatory cytokine TNFα. Firstly we measured using MCF7 cells growing in estrogen-depleted media the transcriptome changes induced by doxorubicin (doxo) and 5-fluorouracil (5FU), two different drugs both able to stabilize and activate the p53 protein. We next obtained the expression profiles in the presence of E2 with or without doxo or 5FU. We also measured transcriptome changes in response to TNFαalone or in combination with doxo and/or E2. All these analyses were conducted using the same batch of MCF7 cells (wild type for p53, ERα, ERβ -weakly-, and NFkB positive) that we had previously used to characterize the cis-mediated transcriptional cooperation between p53 and ER at the FLT1 gene. Keywords: transcription factor, transcriptional networks, p53, ER, NFkB, p53-ER-NFkB crosstalk, doxorubicin, 5-fluorouracil, 17-β estradiol, TNFα, combined genotoxic, estrogenic and inflammatory responses, composite DNA binding site signatures, MCF7. The cooperation at the transcriptional level among p53, ERs and NFkB was analyzed by transcriptome analysis in response to different stimuli (doxo or 5FU, E2, TNFα). To identify mRNA molecules that would be modulated by the coordinated activity of the three TFs, gene expression signals derived from the combinatorial treatment were compared by microarrays analyses to those obtained from each drug when individually administered. Total RNA was isolated from MCF7 cells grown in estrogen-depleted medium and treated so as to stimulate the activity of the three different transcription factors (p53, ERs and NFkB). Cells lysates were collected after 10 hours from the treatments. All experiments were run from triplicate to septuples.
2011-06-01 | E-GEOD-24065 | biostudies-arrayexpress