Homo sapiens
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ABSTRACT:
PROVIDER: PRJNA277954 | ENA |
REPOSITORIES: ENA
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Project description:Ambient O2 pressure induces NF-kB1/RelA related inflammatory response in human lung epithelial cells in vitro
| PRJNA282543 | ENA
Project description:Purpose: Oxygen (O2) levels in cell culture conditions is typically 2-5 fold higher than the physiological O2 levels that most tissues experience in vivo. The ambient atmospheric O2 (21%) is known to induce cell proliferation defects and cellular senescence in stem cell and primary cell cultures. Therefore, culturing these cells under lower O2 levels (2-9%) is currently a standard practice. However, the non-cancerous immortalized cells and cancer cells, which evade cellular senescence are normally cultured under 21% O2 levels and the effects of higher O2 levels on these cells are not fully understood. Methods: Gene expression (RNA seq transcriptomics) analysis of immortalized human bronchial epithelial (BEAS-2B) cells cultured at ambient 21% O2 and lower 10% O2 levels for 3 days and 3 weeks. Further the beneficial effects of cuturing cells under lower oxygen tension is evalulated Results: Our results show NF-κB/RelA mediated activation of pro-inflammatory cytokines as a major outcome of cells being cultured 21% O2. Moreover, we demonstrate increased RelA binding at the NF-κB1/RelA target gene promoters at 21% O2. Interestingly, contrary to cells cultutred at 21% O2, external stress induced by H2O2 exposure did not induce inflammatory response in cells grown at 10% O2, suggesting increased ability to handle external stress in cells cultured at lower O2 levels.
2016-01-26 | GSE68378 | 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:TNFα has an evolutionary conserved role in mediating inflammation via activation of the transcription factor NF-κB. The functions of individual NF-κB binding sites are not well understood. To identify conserved and functionally important NF-κB binding sites in mammals, we performed ChIP-seq to map the genome-wide binding of RELA and select histone modifications in primary vascular endothelial cells (ECs) isolated from the aortas of human (HAEC), mouse (MAEC) and cow (BAEC), before and after TNFα. The conserved RELA binding sites show strong epigenetic changes in response to TNFα and enrich near genes controlling vascular development and pro-inflammatory responses. Our method identifies novel modes of RELA-chromatin interactions that are conserved in mammals and shared between multiple cell-types. Particularly, genomic regions bound by RELA prior to stimulation are important responders during TNFα stimulation. We use CRISPR/Cas9 genome editing to validate the roles of the conserved RELA pre-bound sites near pro-inflammatory genes such as CCL2 and PLK2. Our evolutionary approach describes new aspects of mammalian NF-κB biology including its role within super-enhancers and relevance in inflammatory disorders.
2020-10-03 | E-MTAB-7889 | biostudies-arrayexpress
Project description:The central nervous system normally functions at O2 levels which would be regarded as hypoxic by most other tissues. However, most in vitro studies of neurons and astrocytes are conducted under hyperoxic conditions without consideration of O2-dependent cellular adaptation. We analyzed the reactivity of astrocytes to 1, 4 and 9% O2 tensions compared to the cell culture standard of 20% O2, to investigate their ability to sense and translate this O2 information to transcriptional activity. Variance of ambient O2 tension for rat astrocytes resulted in profound changes in ribosomal activity, cytoskeletal and energy-regulatory mechanisms and cytokine-related signaling. Clustering of transcriptional regulation patterns revealed four distinct response pattern groups that directionally pivoted around the 4% O2 tension, or demonstrated coherent ascending/decreasing gene expression patterns in response to diverse oxygen tensions. Immune response and cell cycle/cancer-related signaling pathway transcriptomic subsets were significantly activated with increasing hypoxia, whilst hemostatic and cardiovascular signaling mechanisms were attenuated with increasing hypoxia. Our data indicate that variant O2 tensions induce specific and physiologically-focused transcript regulation patterns that may underpin important physiological mechanisms that connect higher neurological activity to astrocytic function and ambient oxygen environments. These strongly defined patterns demonstrate a strong bias for physiological transcript programs to pivot around the 4% O2 tension, while uni-modal programs that do not, appear more related to pathological actions. The functional interaction of these transcriptional ‘programs’ may serve to regulate the dynamic vascular responsivity of the central nervous system during periods of stress or heightened activity.
2012-09-20 | GSE29296 | GEO
Project description:Proteasome-mediated degradation of chromatin-bound NF-κB is critical in terminating the transcription of pro-inflammatory genes and can be triggered by Set9-mediated lysine methylation of RelA subunit. However, the E3 ligase targeting methylated RelA remains unknown. Here, we identified two structurally similar WD-40 repeat (WDR) proteins, WSB1 and WSB2, as the E3s that recognize chromatin-bound methylated RelA for polyubiquitination and proteasomal degradation. WSB1/2 specifically recognized methylated lysines (K) 314 and 315 of RelA via their WDR domains. Deletion of WRD in WSB1/2 or mutation of K314/315 of RelA to arginines abolished the interaction between WSB1/2 and RelA. RNA-sequencing of TNF--stimulated WSB1/2 knockdown cells revealed that WSB1/2 negatively regulated a subset of NF-B target genes with reduced polyubiquitination of chromatin-bound RelA. TNF- stimulated the methylation of RelA and the subsequent recruitment of WSB1/2 to the promoters of these NF-B target genes to terminate the transcription. Computational modeling demonstrated that a highly conserved Asp within repeat 3 of WDR domains of WSB1/2 coordinated its interaction with K314/K315 of RelA, with a higher pKa when either of the lysines is methylated. Together, these findings identify novel E3 ligases that target chromatin-bound methylated RelA for proteolysis to prevent sustained NF-κB activation, providing new targets for therapeutic intervention of NF-κB-mediated inflammatory diseases.
2024-05-29 | GSE233286 | GEO
Project description:Background: Ozone (O3) is the predominant oxidant air pollutant associated with respiratory inflammation, lung dysfunction, and worsening preexisting airway diseases. We previously determined that lack of NF-kB signlaing pathway suppressed lung injury and inflammation caused by O3 in mice. The current study was to determine transcriptome mechanisms orchestrated by NF-kB during the development of pulmonary O3 injury. Methods: To investigate the role of NF-kB1 pathway in lung gene expression changes, Nfkb1-deficient (Nfkb1-/-) and wild-type (Nfkb1+/+) mice were exposed to air or 0.3-ppm O3. Total RNAs were isolated from lung homogenates and cDNA microarray analyses were performed to elucidate NF-kB1-directed transcriptomics in basal lungs (air-exposed) as well as in the lung exposed to O3 (48 hr). Results: In air-exposed Nfkb1-/- lungs, leukocyte extravasation/adhesion and antigen presentation genes were overexpressed while immunity genes were suppressed, supporting the dual role of Nf-kB1 homodimer as a transcriptional repressor as well as transcriptional activator and the phenotype of Nfkb1-/- mice (defective response to infection and specific antibody production). After O3 exposure. Nfkb1-/- mice showed suppressed expression of lung cell cycle genes and enhanced expression of DNA damage checkpoint regulation pathway genes, compared to Nfkb1+/+ mice. Conclusion: Overall, deficiency of NF-kB1 in mouse lungs altered transcriptomes to protect lungs from O3-induced inflammation, cell proliferation, and DNA damages.
2021-09-29 | GSE166398 | GEO
Project description:Preclinical studies of primary cancer cells are always done after tumors are removed from patients or animals at ambient atmospheric oxygen (O2, ~21%). However, O2 concentrations in organs are in the ~3-10% range, with most tumors in an hypoxic or 1-2% O2 environment in vivo. Although effects of O2 tension on tumor cell characteristics in vitro have been studied, these studies are done only after tumors are first collected and processed in ambient air. Similarly, sensitivity of primary cancer cells to anti-cancer agents is routinely examined at ambient O2. Here, using both mouse models and human cancers, we demonstrate that tumors collected, processed and propagated at physiologic (physioxia) O2 compared to ambient air display very distinct differences in key signaling networks including Lgr5/Wnt, Yap, and Nrf2/Keap1, nuclear reactive oxygen species levels, alternative splicing, and sensitivity to several targeted therapies including PIK3CAalpha-specific and EGFR inhibitors. Significance: Extra-physiologic oxygen shock/stress (EPHOSS), as noted in cells collected/processed under ambient air, has been demonstrated to have significant impact on numbers and engrafting ability of hematopoietic stem cells. We report deleterious effects of EPHOSS on cancer cell behavior and EPHOSS-mediated effects on cancer cells give misleading information on signaling pathway activation that could severely impact the relevance of these findings. Cancer cells under EPHOSS show higher proliferation rate compared to cells under physioxia and thus are sensitive to anti-proliferative agents. Thus, drugs that show effectiveness on cancer cells collected in ambient air and subjected to EPHOSS may not be effective or as relevant in vivo, results that could partially explain the limited clinical translation of laboratory findings. Evaluating cell signaling and effects of drugs on cancer cells under physiologic O2 prior to in vivo studies could substantially reduce cost and aid in drug discovery relevant to the actual physioxia/pathological status of the tumor cells in vivo.
2022-02-16 | PXD023133 | Pride
Project description:Purpose: The numbers of Vg4+Vd4+gdT17 cells in skin-draining lymph nodes were significantly reduced in imiqimod-treated NF-kB1-/- mice compared to those in IMQ-treated WT mice. To address the mechanism of NF-kB1-mediated proliferation of Vg4+Vd4+gdT17 cells, we performed RNA-sequencing of Vg4+Vd4+gdT cells isolated from the draining lymph nodes. Method: Mice were treated daily with 50 mg of 5% imiquimod cream or sham cream on both ears for 4 days. Single cell suspensions were separated from cervical lymph nodes. Vg4+Vd4+gdT cells were isolated by a cell sorter. N=3 each. Results: Using an optimized data analysis workflow, 552 of the transcripts showed differential expression between the WT and NF-kB1 deficient mice after imiquiod treatment, with a fold change ≥2 and p value <0.05.
2021-06-25 | GSE178874 | GEO