scholarly journals Interferon-γ-dependent stimulation of human involucrin gene expression: STAT1 (signal transduction and activators of transcription 1) protein activates involucrin promoter activity

1999 ◽  
Vol 344 (3) ◽  
pp. 797-802 ◽  
Author(s):  
Hidetoshi TAKAHASHI ◽  
Kazuhiro ASANO ◽  
Satoshi NAKAMURA ◽  
Akemi ISHIDA-YAMAMOTO ◽  
Hajime IIZUKA
Keyword(s):  
Gene Expression ◽  
Signal Transduction ◽  
Promoter Activity ◽  
Expression Vector ◽  
Human Keratinocytes ◽  
Interferon Γ ◽  
Luciferase Reporter ◽  
Potent Inducer ◽  
Ifn Γ ◽  
Involucrin Promoter

Involucrin is one of the precursor proteins of the cornified cell envelope of keratinocytes, and is expressed during the later stages of keratinocyte differentiation. Interferon-γ (IFN-γ), a pleiotropic cytokine with anti-proliferative and immunomodulatory activities, is also a potent inducer of squamous differentiation. Using cultured normal human keratinocytes (NHK cells) and simian virus 40-transformed human keratinocytes (SVHK cells), we investigated the effects of IFN-γ on involucrin gene expression. Expression of involucrin was increased by about 3-fold after treating NHK cells with IFN-γ (100 units/ml). Northern blot analyses revealed that IFN-γ increased the expression of involucrin mRNA. The fragment +42 to -2463 in the 5ʹ-flanking region of the human involucrin gene was subcloned into a luciferase reporter vector and the construct (p2463Luc) was transfected into SVHK cells. p2463Luc produced a 3-fold increase in luciferase activity after IFN-γ treatment. Sequence analysis detected two putative IFN-γ-responsive regions [G1 (positions -883 to -874) and G2 (-784 to -775)]. Deletion analyses of the p2463Luc vector revealed that the G1 region is critical for the IFN-γ-dependent up-regulation of the involucrin gene. Gel-shift analyses revealed that STAT1 (signal transduction and activators of transcription 1) protein bound to the G1 region and that involucrin promoter activity was augmented by transfection of a STAT1 expression vector in the presence of IFN-γ. In contrast, transfection of a STAT1 dominant-negative expression vector suppressed the IFN-γ-dependent up-regulation of involucrin promoter activity. These results indicate that IFN-γ stimulates expression of the human involucrin gene via the G1 (-883 to -874) region of the involucrin gene promoter.

scholarly journals IκBζ augments IL-12– and IL-18–mediated IFN-γ production in human NK cells

Blood ◽  
2011 ◽  
Vol 117 (10) ◽  
pp. 2855-2863 ◽  
Author(s):  
Yashaswini Kannan ◽  
Jianhua Yu ◽  
Raquel M. Raices ◽  
Sudarshan Seshadri ◽  
Min Wei ◽  
...  
Keyword(s):  
Nk Cells ◽  
Promoter Activity ◽  
Human Peripheral Blood ◽  
Interleukin 1 ◽  
Interferon Γ ◽  
Peripheral Blood Lymphocytes ◽  
Lymphocyte Subpopulation ◽  
Luciferase Reporter ◽  
Cytotoxic Lymphocytes ◽  
Ifn Γ

Abstract Interferon-γ (IFN-γ) production by natural killer (NK) cells and cytotoxic lymphocytes is a key component of innate and adaptive immune responses. Because inhibitor of κB-ζ (IκBζ), a Toll-like receptor (TLR)/interleukin-1 receptor (IL-1R) inducible transcription factor, regulates IFN-γ production in KG-1 cells, we tested IκBζ's role in the classic lymphocyte pathway of IL-12/IL-18–induced IFN-γ. Upon stimulation with IL-12/IL-18, monocyte-depleted human peripheral blood lymphocytes expressed the 79-kDa form of IκBζ and released IFN-γ. CD56+ NK cells were shown to be the IκBζ-producing lymphocyte subpopulation, which also released abundant IFN-γ in response to IL-12/IL-18. Importantly, IκBζ was undetectable in CD56− lymphocytes where IFN-γ release was 10-fold lower. In addition, small interfering RNA knockdown of IκBζ suppressed IFN-γ expression in CD56+ cells. The association of IκBζ with the IFN-γ promoter was documented by chromatin immunoprecipitation. IFN-γ promoter activity from IκBζ overexpression was confirmed by luciferase reporter assay. Finally, IκBζ coprecipitated with p65 and p50 NF-κB in NK cells in response to IL-12/IL-18, suggesting that IκBζ's effects on IFN-γ promoter activity are coregulated by NF-κB. These results suggest that IκBζ functions as an important regulator of IFN-γ in human NK cells, further expanding the class of IκBζ-modulated genes.

scholarly journals Sequence of the 5′-flanking region and promoter activity of the human mucin gene MUC5B in different phenotypes of colon cancer cells

2000 ◽  
Vol 348 (3) ◽  
pp. 675-686 ◽  
Author(s):  
Isabelle VAN SEUNINGEN ◽  
Michaël PERRAIS ◽  
Pascal PIGNY ◽  
Nicole PORCHET ◽  
Jean-Pierre AUBERT
Keyword(s):  
Gene Expression ◽  
Transcription Start Site ◽  
Promoter Activity ◽  
Luciferase Reporter ◽  
Nuclear Factor ◽  
Start Site ◽  
Transcription Start ◽  
Mucin Gene ◽  
Intron 1 ◽  
Flanking Region

Control of gene expression in intestinal cells is poorly understood. Molecular mechanisms that regulate transcription of cellular genes are the foundation for understanding developmental and differentiation events. Mucin gene expression has been shown to be altered in many intestinal diseases and especially cancers of the gastrointestinal tract. Towards understanding the transcriptional regulation of a member of the 11p15.5 human mucin gene cluster, we have characterized 3.55 kb of the 5ʹ-flanking region of the human mucin gene MUC5B, including the promoter, the first two exons and the first intron. We report here the promoter activity of successively 5ʹ-truncated sections of 956 bases of this region by fusing it to the coding region of a luciferase reporter gene. The transcription start site was determined by primer-extension analysis. The region upstream of the transcription start site is characterized by the presence of a TATA box at bases -32/-26, DNA-binding elements for transcription factors c-Myc, N-Myc, Sp1 and nuclear factor ĸB as well as putative activator protein (AP)-1-, cAMP-response-element-binding protein (CREB)-, hepatocyte nuclear factor (HNF)-1-, HNF-3-, TGT3-, gut-enriched Krüppel factor (GKLF)-, thyroid transcription factor (TTF)-1- and glucocorticoid receptor element (GRE)-binding sites. Intron 1 of MUC5B was also characterized, it is 2511 nucleotides long and contains a DNA segment of 259 bp in which are clustered eight tandemly repeated GA boxes and a CACCC box that bind Sp1. AP-2α and GATA-1 nuclear factors were also shown to bind to their respective cognate elements in intron 1. In transfection studies the MUC5B promoter showed a cell-specific activity as it is very active in mucus-secreting LS174T cells, whereas it is inactive in Caco-2 enterocytes and HT-29 STD (standard) undifferentiated cells. Within the promoter, maximal transcription activity was found in a segment covering the first 223 bp upstream of the transcription start site. Finally, in co-transfection experiments a transactivating effect of Sp1 on to MUC5B promoter was seen in LS174T and Caco-2 cells.

scholarly journals Progesterone Alters Kynurenine Pathway Activation in IFN-γ-Activated Macrophages – Relevance for Neuroinflammatory Diseases

2016 ◽  
Vol 9 ◽  
pp. IJTR.S40332 ◽  
Author(s):  
J. de Bie ◽  
C. K. Lim ◽  
G. J. Guillemin
Keyword(s):  
Inflammatory Marker ◽  
Interferon Γ ◽  
Gender Disparity ◽  
Kynurenine Pathway ◽  
Gonadal Hormones ◽  
Potent Inducer ◽  
Sexual Dimorphisms ◽  
Pathway Activation ◽  
Ifn Γ ◽  
Shed Light

We have previously demonstrated that the kynurenine pathway (KP), the major biochemical pathway for tryptophan metabolism, is dysregulated in many inflammatory disorders that are often associated with sexual dimorphisms. We aimed to identify a potential functional interaction between the KP and gonadal hormones. We have treated primary human macrophages with progesterone in the presence and absence of inflammatory cytokine interferongamma (interferon-γ) that is known to be a potent inducer of regulating the KP enzyme. We found that progesterone attenuates interferon-γ-induced KP activity, decreases the levels of the excitotoxin quinolinic acid, and increases the neuroprotective kynurenic acid levels. We also showed that progesterone was able to reduce the inflammatory marker neopterin. These results may shed light on the gender disparity in response to inflammation.

Phospholipase A 2 Metabolites Mediate Endothelin Stimulation of the Human Brain Natriuretic Peptide Promoter

Hypertension ◽  
2000 ◽  
Vol 36 (suppl_1) ◽  
pp. 721-721
Author(s):  
Quan He
Keyword(s):  
Gene Expression ◽  
Brain Natriuretic Peptide ◽  
Natriuretic Peptide ◽  
Promoter Activity ◽  
Luciferase Activity ◽  
Phospholipase A ◽  
Luciferase Reporter ◽  
Luciferase Reporter Gene ◽  
P450 Monooxygenase ◽  
Stimulation Of

P155 Brain natriuretic peptide (BNP) gene expression accompanies cardiac hypertrophy and heart failure. The vasoconstrictor endothelin-1 (ET)may be involved in the development of these diseases. ET has also been shown to activate phospholipase A 2 (PLA 2 ). Thus we studied whether ET and PLA 2 metabolites regulate BNP gene expression. The hBNP promoter (-1818 to + 100) coupled to a luciferase reporter gene was transferred into neonatal ventricular myocytes (NVM),and luciferase activity was measured as an index of promoter activity. ET (10 -7 M)induced BNP mRNA in NVM as assessed by Northern blot. It also stimulated the hBNP promoter 4-fold vs control, an effect completely inhibited by actinomycin D. To test the involvement of different PLA 2 isoforms, transfected cells were treated with the Ca ++ -independent PLA 2 (iPLA 2 )inhibitor bromoenol lactone (BEL), the cytosolic PLA 2 inhibitor methyl arachidonyl fluorophosphonate, or the secretory PLA 2 inhibitor ONO-RS-082 prior to stimulation with ET. Only the iPLA 2 inhibitor BEL prevented ET-stimulated hBNP promoter activity. The PLA 2 metabolite lysophosphatidic acid (LPA) also activated the hBNP promoter (2.2-fold; n = 3), but lysophosphatidylcholine did not. To test whether arachidonic acid metabolites are involved in ET’s effect, cells were pretreated with either a lipoxygenase (LO), cyclooxygenase, or p450 monooxygenase inhibitor. Only the LO inhibitor baicalein prevented ET stimulation of the hBNP promoter. Finally, we studied the involvement of cis elements in ET-stimulated hBNP promoter activity. Deletion of BNP promoter sequences from -1818 to -408 and from -408 to -40 reduced ET’s effect by 54% and 78%, respectively. Moreover, ET-stimulated luciferase activity was reduced by 53% when the GATA element (at position -85 relative to the start site of transcription) was mutated. These data suggest that: 1) ET activates the hBNP promoter through a transcriptional mechanism; 2) LPA, perhaps generated by a BEL-sensitive iPLA 2 , is involved in ET’s effect; 3) a LO pathway may also mediate ET signaling; and 4) ET regulation of the hBNP promoter targets both distal and proximal cis elements, including GATA.

scholarly journals Lipopolysaccharide-induced interleukin-8 gene expression in human granulocytes: transcriptional inhibition by interferon-γ

1995 ◽  
Vol 310 (3) ◽  
pp. 751-755 ◽  
Author(s):  
M A Cassatella ◽  
S Gasperini ◽  
F Calzetti ◽  
P P McDonald ◽  
G Trinchieri
Keyword(s):  
Gene Expression ◽  
Interferon Γ ◽  
Interleukin 8 ◽  
Polymorphonuclear Leucocytes ◽  
Mrna Accumulation ◽  
Ifn Gamma ◽  
Potent Inducer ◽  
Transcriptional Inhibition ◽  
Human Granulocytes ◽  
New Protein

We recently showed that lipopolysaccharide (LPS) is a potent inducer of interleukin-8 (IL-8) expression in human polymorphonuclear leucocytes (PMN), at the level of both mRNA and protein, and that interferon-gamma (IFN gamma) inhibits IL-8 mRNA accumulation in stimulated PMN. To further define the molecular basis of the regulation of IL-8 gene expression in PMN, we investigated the effects of LPS and IFN gamma at both the transcriptional and post-transcriptional levels. As determined by Northern blot analysis, new protein synthesis was not required for the induction of IL-8 mRNA expression by LPS. Neither did the half-life of IL-8 mRNA in LPS-treated PMN differ from that observed in untreated cells. However, nuclear run-on analysis revealed that LPS increased the transcription of the IL-8 and IL-1 beta genes and that, in LPS-activated cells, IFN gamma markedly inhibited the rate of IL-8 gene transcription, but not that of IL-1 beta. IFN gamma did not affect IL-8 mRNA stability in LPS-treated PMN, indicating that the cytokine does not regulate LPS-induced IL-8 gene expression through post-transcriptional events. These results provide the first evidence that human granulocytes can actively transcribe the IL-8 gene, and that transcriptional inhibition is the mechanism by which IFN gamma inhibits IL-8 gene expression in PMN.

scholarly journals Interferon-γ Inhibits STAT6 Signal Transduction and Gene Expression in Human Airway Epithelial Cells

2004 ◽  
Vol 31 (5) ◽  
pp. 573-582 ◽  
Author(s):  
Nicola M. Heller ◽  
Satoshi Matsukura ◽  
Steve N. Georas ◽  
Mark R. Boothby ◽  
Paul B. Rothman ◽  
...  
Keyword(s):  
Gene Expression ◽  
Signal Transduction ◽  
Epithelial Cells ◽  
Interferon Γ ◽  
Airway Epithelial Cells ◽  
Airway Epithelial ◽  
Human Airway ◽  
Human Airway Epithelial Cells

scholarly journals Regulation of basal promoter activity of the human thiamine pyrophosphate transporter SLC44A4 in human intestinal epithelial cells

2015 ◽  
Vol 308 (9) ◽  
pp. C750-C757 ◽  
Author(s):  
Svetlana M. Nabokina ◽  
Mel Brendan Ramos ◽  
Judith E. Valle ◽  
Hamid M. Said
Keyword(s):  
Gene Expression ◽  
Transcription Factors ◽  
Epithelial Cells ◽  
Promoter Activity ◽  
Minimal Promoter ◽  
Thiamine Pyrophosphate ◽  
Luciferase Reporter ◽  
Uptake System ◽  
Colonic Epithelial Cells ◽  
Basal Promoter Activity

Microbiota of the large intestine synthesize considerable amount of vitamin B1 in the form of thiamine pyrophosphate (TPP). There is a specific high-affinity regulated carrier-mediated uptake system for TPP in human colonocytes (product of the SLC44A4 gene). The mechanisms of regulation of SLC44A4 gene expression are currently unknown. In this study, we characterized the SLC44A4 minimal promoter region and identified transcription factors important for basal promoter activity in colonic epithelial cells. The 5′-regulatory region of the SLC44A4 gene (1,022 bp) was cloned and showed promoter activity upon transient transfection into human colonic epithelial NCM460 cells. With the use of a series of 5′- and 3′-deletion luciferase reporter constructs, the minimal genomic region that required basal transcription of the SLC44A4 gene expression was mapped between nucleotides −178 and +88 (using the distal transcriptional start site as +1). Mutational analysis performed on putative cis-regulatory elements established the involvement of ETS/ELF3 [E26 transformation-specific sequence (ETS) proteins], cAMP-responsive element (CRE), and SP1/GC-box sequence motifs in basal SLC44A4 promoter activity. By means of EMSA, binding of ELF3 and CRE-binding protein-1 (CREB-1) transcription factors to the SLC44A4 minimal promoter was shown. Contribution of CREB into SLC44A4 promoter activity was confirmed using NCM460 cells overexpressing CREB. We also found high expression of ELF3 and CREB-1 in colonic (NCM460) compared with noncolonic (ARPE19) cells, suggesting their possible contribution to colon-specific pattern of SLC44A4 expression. This study represents the first characterization of the SLC44A4 promoter and reports the importance of both ELF3 and CREB-1 transcription factors in the maintenance of basal promoter activity in colonic epithelial cells.

scholarly journals Specific Inhibition of Interferon Signal Transduction Pathways by Adenoviral Infection

2001 ◽  
Vol 276 (50) ◽  
pp. 47136-47142 ◽  
Author(s):  
Theresa D. Joseph ◽  
Dwight C. Look
Keyword(s):  
Gene Expression ◽  
Signal Transduction ◽  
Transcription Factor ◽  
Epithelial Cells ◽  
Molecular Mechanisms ◽  
Airway Epithelial Cells ◽  
Signal Transducer ◽  
Airway Epithelial ◽  
Complex Assembly ◽  
Ifn Γ

Adenoviral evolution has generated strategies to resist host cell antiviral systems, but molecular mechanisms for evasion of interferon (IFN) effects by adenoviruses during late-phase infection are poorly defined. In this study, we examined adenovirus type 5 (AdV) effects on IFN-γ-dependent gene expression and Janus family kinase-signal transducer and activator of transcription signaling components in human tracheobronchial epithelial cells. We found that AdV infection specifically inhibited IFN-γ-dependent gene expression in airway epithelial cells without evidence of epithelial cell injury or generation of a soluble extracellular inhibitor. Furthermore, infection with AdV for 18–24 h blocked phosphorylation/activation of the Stat1 transcription factor that regulates IFN-γ-dependent genes. Although AdV also inhibited IFN-α-dependent phosphorylation of Stat1 and Stat2, interleukin-4-dependent phosphorylation of the related transcription factor Stat6 was not affected, indicating that the virus selectively affected specific signaling pathways. Our results indicate that AdV inhibition of the IFN-γ signal transduction cascade occurs through loss of ligand-induced receptor complex assembly and consequent component phosphorylation and suggest that lack of complex assembly is due to decreased expression of the IFN-γR2 chain of the IFN-γ receptor. IFN-γR2 is required at an early step in Janus family kinase-signal transducer and activator of transcription pathway activation and is expressed at low levels in airway epithelial cells, supporting the concept that adenoviral down-regulation of the level of this IFN-γ receptor component allows for persistent modulation of IFN-γ-dependent gene expression.

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