Ontology highlight
ABSTRACT:
PROVIDER: PRJNA1041289 | ENA |
REPOSITORIES: ENA
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Project description:A member of the nuclear receptors, retinoic acid-related orphan receptor a (RORa) is an important transcription factor for various biological processes including circadian rhythm, metabolic regulation, immune cell development and cancer. Here we found that RORa is important for intestinal homeostasis by negatively regulating the transcriptional activity of NF-kB, a major inflammatory regulator in intestinal epithelial cells. Intestinal Rora-deficient mice found were highly susceptible to DSS-induced injury. Transcriptome analysis showed that intestine-specific Rora deletion causes regulatory impairment of NF-kB signaling leading to excessive inflammatory responses. RORa specifically binds to the NF-kB target promoter and inhibits transcriptional activity for transcriptional repression of NF-kB activity via histone deacetylase 3 (HDAC3). Taken together, RORa plays a pivotal role in the homeostatic regulation of intestinal epithelial cells in inflammatory conditions. Therefore, therapeutic strategies designed to modulate RORa activity may be beneficial in the treatment of chronic inflammatory diseases such as Inflammatory bowel disease (IBD).
2019-09-30 | GSE121977 | GEO
Project description:The canonical NF-kB module induces nuclear translocation of RelA heterodimers from the latent cytoplasmic complexes. RelA directs inflammatory immune responses against microbial entities. However, aberrant RelA activity also triggers destructive inflammation, including those associated with inflammatory bowel disease (IBD). What provokes this pathological RelA activity remains unclear. As such, the noncanonical NF-kB pathway activates RelB heterodimers and mediates immune organogenesis. Because NF-kB-activating pathways are interlinked, we asked if noncanonical NF-kB signaling exacerbated intestinal inflammation. Our investigation revealed recurrent engagement of the noncanonical pathway in human IBD. In a mouse model of chemical colitis, the noncanonical NF-kB signaling gene Nfkb2 aggravated inflammation by amplifying the RelA activity induced in intestinal epithelial cells. Our mechanistic studies clarified that noncanonical signaling augmented the abundance of latent RelA complexes leading to hyperactive canonical NF-kB response in the colitogenic gut. In sum, latent dimer homeostasis appears to link noncanonical NF-kB signaling to RelA-driven inflammatory pathologies.
2021-07-07 | GSE148577 | GEO
Project description:The nuclear factor-kB (NF-kB) family of transcription factors is important for hematopoietic function, including development, maintenance, and differentiation of different hematopoietic lineages in response to cytokines and infection. Although ligand-independent or basal NF-kB signaling is required for HSC homeostasis in the absence of inflammation, the upstream tonic mediators of NF-kB signaling are not known. Herein we describe TNF receptor associated factor 6 (TRAF6) as an essential regulator of HSC homeostasis by preserving self-renewal and quiescence through basal activation of NF-kB. Hematopoietic-specific deletion of Traf6 resulted in impaired HSC self-renewal and fitness. Gene expression, RNA splicing, and molecular analyses of Traf6-deficient HSPC revealed changes in adaptive immune signaling, innate immune signaling, and NF-kB signaling, indicating that signaling via TRAF6 in the absence of cytokine stimulation and/or infection occurs in HSPC and is required for HSC function. In addition, we established that loss of NF-kB signaling is responsible for the major hematopoietic defects observed in Traf6-deficient HSPC as deletion of IKKb similarly resulted in impaired HSC self-renewal and fitness. Taken together, our observations position TRAF6 as an essential regulator of HSC homeostasis by maintaining a minimal threshold level of IKKb/NF-kB signaling.
2018-01-31 | GSE109050 | GEO
Project description:<p>Nasopharyngeal carcinoma (NPC) is an aggressive head and neck cancer characterized by Epstein-Barr virus (EBV) infection and dense lymphocyte infiltration. The scarcity of NPC genomic data hinders the understanding of NPC biology, disease progression, and rational therapy design. Here, we performed whole-exome sequencing (WES) on 111 micro-dissected EBV-positive NPCs, with 15 cases subjected to further whole-genome sequencing (WGS), to determine its mutational landscape. We identified enrichment for genomic aberrations of multiple negative regulators of the NF-kB pathway in a total of 41% of cases including CYLD, TRAF3, NFKBIA and NLRC5. Functional analysis confirmed novel inactivating CYLD mutations as drivers for NPC cell growth. The EBV oncoprotein latent member protein 1 (LMP1) functions to constitutively activate NF-kB signaling, and we observed mutual exclusivity among somatic NF-kB pathway aberrations and LMP1-overexpression, suggesting that NF-kB activation is selected for by both somatic and viral events during NPC pathogenesis.</p>
| phs001244 | dbGaP
Project description:Human intestinal macrophages contribute to tissue homeostasis in noninflamed mucosa through profound down-regulation of pro-inflammatory cytokine release. Here, we show that this down-regulation extends to Toll-like receptor (TLR)-induced cytokine release, as intestinal macrophages expressed TLR3-TLR9 but did not release cytokines in response to TLR-specific ligands. Likely contributing to this unique functional profile, intestinal macrophages expressed markedly down-regulated adapter proteins MyD88 and Toll interleukin receptor 1 domain-containing adapter-inducing interferon beta, which together mediate all TLR MyD88-dependent and -independent NF-kappaB signaling, did not phosphorylate NF-kappaB p65 or Smad-induced IkappaBalpha, and did not translocate NF-kappaB into the nucleus. Importantly, transforming growth factor-beta released from intestinal extracellular matrix (stroma) induced identical down-regulation in the NF-kappaB signaling and function of blood monocytes, the exclusive source of intestinal macrophages. Our findings implicate stromal transforming growth factor-beta-induced dysregulation of NF-kappaB proteins and Smad signaling in the differentiation of pro-inflammatory blood monocytes into noninflammatory intestinal macrophages. Comparison of unstimulated monocytes and macrophages, and flagellin stimulated monocytes and macrophages.
2010-07-07 | E-GEOD-22373 | biostudies-arrayexpress
Project description:T cell activation following antigen binding to the T cell receptor (TCR) involves the mobilization of intracellular calcium (Ca2+) to activate the key transcription factors NFAT and NF-κB. The mechanism of NFAT activation by Ca2+ has been determined; however, the role of Ca2+ in controlling NF-κB signaling is poorly understood and the source of Ca2+ required for NF-κB activation is unknown. We demonstrate that TCR- but not TNF- induced NF-κB signaling upstream of IκB kinase (IKK) activation absolutely requires the influx of extracellular Ca2+ via STIM1-dependent CRAC/Orai channels. We further show that Ca2+ influx controls phosphorylation of the NF-κB protein p65 on Ser536 and that this post- translational modification controls its nuclear localization and transcriptional activation. Notably our data reveal that this role for Ca2+ is entirely separate from its upstream control of IκBα degradation, thereby identifying a novel Ca2+- dependent distal step in TCR-induced NF-κB activation. Finally, we demonstrate that this control of distal signaling occurs via Ca2+-dependent PKCk-mediated phosphorylation of p65. Thus, we establish the source of Ca2+ required for TCR induced NF-kB activation and we define a new distal Ca2+-dependent checkpoint in TCR-induced NF-kB signaling that has broad implications for the control of immune cell development and T cell functional specificity. 3 treatments were analyzed, with biological replicates for each treatment. In addition, three timepoints (1 hour, 4 hour, and 8 hour) were examined for each treatment, as well as an untreated control. In total 19 samples were analyzed
2016-01-14 | E-GEOD-76804 | biostudies-arrayexpress
Project description:The IkB-Kinase (IKK)-NF-kB signaling pathway plays a multifaceted role in Inflammatory Bowel Disease: One the one hand it protects cells from apoptosis, but on the other, it activates transcription of numerous inflammatory cytokines and chemokines. To examine the role of constitutive NF-kB signaling in intestinal epithelium cells (IEC), we generated a mouse model with a tissue-specific knockout of the direct inhibitor of NF-kB, IkBα. We demonstrate that in IκBαIEC-KO mice, constitutive activation of NF-kB in epithelium leads to abnormal intestinal development, enlarged peyer’s patches, loss of Paneth cells, and spontaneous inflammation. We performed expression analysis of IκBαIEC-KO mice compared to wildtype by using the Affymetrix array Clariom S mouse.
2020-03-22 | GSE139251 | GEO
Project description:The ability of dying cells to activate antigen presenting cells (APCs) is carefully controlled to avoid unwarranted inflammatory responses. Here we show that engulfed cells only containing cytosolic dsDNA species (viral or synthetic) or cyclic di-nucleotides (CDNs) are able to stimulate APCs, via extrinsic STING-signaling. HEK293 cells containing double strand DNA robustly induced the production of cytokines in macrophages that was dependent on extrinsic STING signaling within the macrophage.
2018-09-04 | GSE110929 | GEO
Project description:T cell activation following antigen binding to the T cell receptor (TCR) involves the mobilization of intracellular calcium (Ca2+) to activate the key transcription factors NFAT and NF-κB. The mechanism of NFAT activation by Ca2+ has been determined; however, the role of Ca2+ in controlling NF-κB signaling is poorly understood and the source of Ca2+ required for NF-κB activation is unknown. We demonstrate that TCR- but not TNF- induced NF-κB signaling upstream of IκB kinase (IKK) activation absolutely requires the influx of extracellular Ca2+ via STIM1-dependent CRAC/Orai channels. We further show that Ca2+ influx controls phosphorylation of the NF-κB protein p65 on Ser536 and that this post- translational modification controls its nuclear localization and transcriptional activation. Notably our data reveal that this role for Ca2+ is entirely separate from its upstream control of IκBα degradation, thereby identifying a novel Ca2+- dependent distal step in TCR-induced NF-κB activation. Finally, we demonstrate that this control of distal signaling occurs via Ca2+-dependent PKCk-mediated phosphorylation of p65. Thus, we establish the source of Ca2+ required for TCR induced NF-kB activation and we define a new distal Ca2+-dependent checkpoint in TCR-induced NF-kB signaling that has broad implications for the control of immune cell development and T cell functional specificity.
2016-01-14 | GSE76804 | GEO
Project description:Chronic NF-kB activation in inflammation and cancer has long been linked to persistent activation of NF-kB–responsive gene promoters. However, NF-kB factors also massively bind to gene bodies. Here, we demonstrate that recruitment of the NF-kB factor RELA to intragenic regions regulates alternative splicing upon NF-kB activation by the viral oncogene Tax of HTLV-1. Integrative analyses of RNA splicing and chromatin occupancy, combined with chromatin tethering assays, demonstrate that DNA-bound RELA interacts with and recruits the splicing regulator DDX17, in an NF-kB activation–dependent manner. This leads to alternative splicing of target exons due to the RNA helicase activity of DDX17. Similar results were obtained upon Tax-independent NF-kB activation, indicating that Tax likely exacerbates a physiological process where RELA provides splice target specificity. Collectively, our results demonstrate a physical and direct involvement of NF-kB in alternative splicing regulation, which significantly revisits our knowledge of HTLV-1 pathogenesis and other NF-kB–related diseases.
2020-05-12 | GSE123752 | GEO