scholarly journals High Dose IFN-β Activates GAF to Enhance Expression of ISGF3 Target Genes in MLE12 Epithelial Cells

2021 ◽  
Vol 12 ◽  
Author(s):  
Kensei Kishimoto ◽  
Catera L. Wilder ◽  
Justin Buchanan ◽  
Minh Nguyen ◽  
Chidera Okeke ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Epithelial Cells ◽  
Target Genes ◽  
Lung Epithelial Cells ◽  
High Dose ◽  
Sequence Motifs ◽  
Host Immune Responses ◽  
Interferon Stimulated Genes ◽  
Transcription Factor Complex

Interferon β (IFN-β) signaling activates the transcription factor complex ISGF3 to induce gene expression programs critical for antiviral defense and host immune responses. It has also been observed that IFN-β activates a second transcription factor complex, γ-activated factor (GAF), but the significance of this coordinated activation is unclear. We report that in murine lung epithelial cells (MLE12) high doses of IFN-β indeed activate both ISGF3 and GAF, which bind to distinct genomic locations defined by their respective DNA sequence motifs. In contrast, low doses of IFN-β preferentially activate ISGF3 but not GAF. Surprisingly, in MLE12 cells GAF binding does not induce nearby gene expression even when strongly bound to the promoter. Yet expression of interferon stimulated genes is enhanced when GAF and ISGF3 are both active compared to ISGF3 alone. We propose that GAF may function as a dose-sensitive amplifier of ISG expression to enhance antiviral immunity and establish pro-inflammatory states.

scholarly journals High dose IFN-β activates GAF to enhance expression of ISGF3 target genes in epithelial cells

2020 ◽  
Author(s):  
Kensei Kishimoto ◽  
Catera Wilder ◽  
Justin Buchanan ◽  
Minh Nguyen ◽  
Chidera Okeke ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Epithelial Cells ◽  
Target Genes ◽  
High Dose ◽  
Sequence Motifs ◽  
Respiratory Epithelial Cells ◽  
Host Immune Responses ◽  
Interferon Stimulated Genes ◽  
Respiratory Epithelial

AbstractInterferon β (IFN-β) signaling activates the transcription factor complex ISGF3 to induce gene expression programs critical for antiviral defense and host immune responses. It has also been observed that IFN-β activates a second transcription factor, γ-activated factor (GAF), but the significance of this coordinated activation is unclear. We report that in respiratory epithelial cells high doses of IFN-β indeed activate both ISGF3 and GAF, which bind to distinct genomic locations defined by their respective DNA sequence motifs. In contrast, low doses of IFN-β preferentially activate ISGF3 but not GAF. Surprisingly, in epithelial cells GAF binding does not induce nearby gene expression even when strongly bound to the promoter. Yet expression of interferon stimulated genes is enhanced when GAF and ISGF3 are both active compared to ISGF3 alone. Our data suggest that GAF enhances ISGF3 target gene expression by co-localizing with ISGF3 at some promoters and facilitating chromosome looping between distal enhancers and other promoters. We propose that GAF may function as a dose-sensitive amplifier of ISG expression to enhance antiviral immunity and establish pro-inflammatory states in respiratory epithelial cells.One sentence summaryGAF is transcriptionally inactive in epithelial cells but enhances expression of ISGF3 target genes, thus functioning as a dose-sensitive amplifier of the IFN-β response.

scholarly journals Effector ExoU from the Type III Secretion System Is an Important Modulator of Gene Expression in Lung Epithelial Cells in Response to Pseudomonas aeruginosa Infection

2003 ◽  
Vol 71 (10) ◽  
pp. 6035-6044 ◽  
Author(s):  
B. McMorran ◽  
L. Town ◽  
E. Costelloe ◽  
J. Palmer ◽  
J. Engel ◽  
...  
Keyword(s):  
Gene Expression ◽  
Pseudomonas Aeruginosa ◽  
Transcription Factor ◽  
Epithelial Cells ◽  
Type Iii Secretion ◽  
Lung Epithelial Cells ◽  
Type Iii ◽  
Lung Epithelial ◽  
Factor C ◽  
Host Genes

ABSTRACT Pseudomonas aeruginosa is an important pathogen in immunocompromised patients and secretes a diverse set of virulence factors that aid colonization and influence host cell defenses. An important early step in the establishment of infection is the production of type III-secreted effectors translocated into host cells by the bacteria. We used cDNA microarrays to compare the transcriptomic response of lung epithelial cells to P. aeruginosa mutants defective in type IV pili, the type III secretion apparatus, or in the production of specific type III-secreted effectors. Of the 18,000 cDNA clones analyzed, 55 were induced or repressed after 4 h of infection and could be classified into four different expression patterns. These include (i) host genes that are induced or repressed in a type III secretion-independent manner (32 clones), (ii) host genes induced specifically by ExoU (20 clones), and (iii) host genes induced in an ExoU-independent but type III secretion dependent manner (3 clones). In particular, ExoU was essential for the expression of immediate-early response genes, including the transcription factor c-Fos. ExoU-dependent gene expression was mediated in part by early and transient activation of the AP1 transcription factor complex. In conclusion, the present study provides a detailed insight into the response of epithelial cells to infection and indicates the significant role played by the type III virulence mechanism in the initial host response.

Nitric oxide increases IL-8 gene transcription and mRNA stability to enhance IL-8 gene expression in lung epithelial cells

2004 ◽  
Vol 287 (4) ◽  
pp. L764-L773 ◽  
Author(s):  
Loretta Sparkman ◽  
Vijayakumar Boggaram
Keyword(s):  
Gene Expression ◽  
Nitric Oxide ◽  
Protein Kinase ◽  
Epithelial Cells ◽  
Gene Transcription ◽  
Mrna Stability ◽  
Inflammatory Responses ◽  
Lung Epithelial Cells ◽  
Mrna Levels ◽  
Lung Epithelial

Interleukin (IL)-8, a C-X-C chemokine, is a potent chemoattractant and an activator for neutrophils, T cells, and other immune cells. The airway and respiratory epithelia play important roles in the initiation and modulation of inflammatory responses via production of cytokines and surfactant. The association between elevated levels of nitric oxide (NO) and IL-8 in acute lung injury associated with sepsis, acute respiratory distress syndrome, respiratory syncytial virus infection in infants, and other inflammatory diseases suggested that NO may play important roles in the control of IL-8 gene expression in the lung. We investigated the role of NO in the control of IL-8 gene expression in H441 lung epithelial cells. We found that a variety of NO donors significantly induced IL-8 mRNA levels, and the increase in IL-8 mRNA was associated with an increase in IL-8 protein. NO induction of IL-8 mRNA was due to increases in IL-8 gene transcription and mRNA stability. NO induction of IL-8 mRNA levels was not inhibited by 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one and KT-5823, inhibitors of soluble guanylate cyclase and protein kinase G, respectively, and 8-bromo-cGMP did not increase IL-8 mRNA levels. This indicated that NO induces IL-8 mRNA levels independently of changes in the intracellular cGMP levels. NO induction of IL-8 mRNA was significantly reduced by inhibitors of extracellular regulated kinase and protein kinase C. IL-8 induction by NO was also reduced by hydroxyl radical scavengers such as dimethyl sulfoxide and dimethylthiourea, indicating the involvement of hydroxyl radicals in the induction process. NO induction of IL-8 gene expression could be a significant contributing factor in the initiation and induction of inflammatory response in the respiratory epithelium.

scholarly journals Selective Up-regulation of Cytokine-induced RANTES Gene Expression in Lung Epithelial Cells by Overexpression of IκBR

1997 ◽  
Vol 272 (32) ◽  
pp. 20191-20197 ◽  
Author(s):  
Prabir Ray ◽  
Liyan Yang ◽  
Dong-Hong Zhang ◽  
Samir K. Ghosh ◽  
Anuradha Ray
Keyword(s):  
Gene Expression ◽  
Epithelial Cells ◽  
Lung Epithelial Cells ◽  
Lung Epithelial

scholarly journals Genome-Wide Analysis of Glucocorticoid-Responsive Transcripts in the Hypothalamic Paraventricular Region of Male Rats

Endocrinology ◽  
2018 ◽  
Vol 160 (1) ◽  
pp. 38-54 ◽  
Author(s):  
Keiichi Itoi ◽  
Ikuko Motoike ◽  
Ying Liu ◽  
Sam Clokie ◽  
Yasumasa Iwasaki ◽  
...  
Keyword(s):  
Gene Expression ◽  
Target Genes ◽  
Receptor Gene ◽  
Male Rats ◽  
Regulatory Mechanisms ◽  
High Dose ◽  
Sequencing Analysis ◽  
Reverse Transcription Pcr ◽  
Genome Wide ◽  
A Genome

Abstract Glucocorticoids (GCs) are essential for stress adaptation, acting centrally and in the periphery. Corticotropin-releasing factor (CRF), a major regulator of adrenal GC synthesis, is produced in the paraventricular nucleus of the hypothalamus (PVH), which contains multiple neuroendocrine and preautonomic neurons. GCs may be involved in diverse regulatory mechanisms in the PVH, but the target genes of GCs are largely unexplored except for the CRF gene (Crh), a well-known target for GC negative feedback. Using a genome-wide RNA-sequencing analysis, we identified transcripts that changed in response to either high-dose corticosterone (Cort) exposure for 12 days (12-day high Cort), corticoid deprivation for 7 days (7-day ADX), or acute Cort administration. Among others, canonical GC target genes were upregulated prominently by 12-day high Cort. Crh was upregulated or downregulated most prominently by either 7-day ADX or 12-day high Cort, emphasizing the recognized feedback effects of GC on the hypothalamic-pituitary-adrenal (HPA) axis. Concomitant changes in vasopressin and apelin receptor gene expression are likely to contribute to HPA repression. In keeping with the pleotropic cellular actions of GCs, 7-day ADX downregulated numerous genes of a broad functional spectrum. The transcriptome response signature differed markedly between acute Cort injection and 12-day high Cort. Remarkably, six immediate early genes were upregulated 1 hour after Cort injection, which was confirmed by quantitative reverse transcription PCR and semiquantitative in situ hybridization. This study may provide a useful database for studying the regulatory mechanisms of GC-dependent gene expression and repression in the PVH.

scholarly journals Functional effects of variation in transcription factor binding highlight long-range gene regulation by epromoters

2019 ◽  
Author(s):  
Joanna Mitchelmore ◽  
Nastasiya Grinberg ◽  
Chris Wallace ◽  
Mikhail Spivakov
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Statistical Power ◽  
Target Genes ◽  
Allelic Variation ◽  
Regulatory Function ◽  
Regulatory Sequences ◽  
Distal Enhancer ◽  
Association Testing ◽  
Gene Regulatory

AbstractIdentifying DNA cis-regulatory modules (CRMs) that control the expression of specific genes is crucial for deciphering the logic of transcriptional control. Natural genetic variation can point to the possible gene regulatory function of specific sequences through their allelic associations with gene expression. However, comprehensive identification of causal regulatory sequences in brute-force association testing without incorporating prior knowledge is challenging due to limited statistical power and effects of linkage disequilibrium. Sequence variants affecting transcription factor (TF) binding at CRMs have a strong potential to influence gene regulatory function, which provides a motivation for prioritising such variants in association testing. Here, we generate an atlas of CRMs showing predicted allelic variation in TF binding affinity in human lymphoblastoid cell lines (LCLs) and test their association with the expression of their putative target genes inferred from Promoter Capture Hi-C and immediate linear proximity. We reveal over 1300 CRM TF-binding variants associated with target gene expression, the majority of them undetected with standard association testing. A large proportion of CRMs showing associations with the expression of genes they contact in 3D localise to the promoter regions of other genes, supporting the notion of ‘epromoters’: dual-action CRMs with promoter and distal enhancer activity.

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