scholarly journals Inflammatory Cytokines Regulate Glycoprotein Subunit β5 of Thyrostimulin through Nuclear Factor-κB

Endocrinology ◽  
2008 ◽  
Vol 150 (5) ◽  
pp. 2237-2243 ◽  
Author(s):  
Chizuko Suzuki ◽  
Hiroshi Nagasaki ◽  
Yoshiki Okajima ◽  
Hidetaka Suga ◽  
Nobuaki Ozaki ◽  
...  

Thyrostimulin is a heterodimeric hormone comprised of two glycoprotein hormone subunits, namely glycoprotein hormone subunit α2 and glycoprotein hormone subunit β5 (GPB5). Immunological studies have revealed that both subunits colocalize in human pituitary corticotroph cells. Although recombinant thyrostimulin protein selectively activates the TSH receptor and has thyrotropic activity in rats, its biological functions have not been clarified. To explore the physiological regulators for the GPB5, the 5′-flanking region of the GPB5 coding sequence up to 3-kb upstream was analyzed by luciferase reporter assays. We found that nuclear factor-κB (NF-κB) markedly activated GPB5 transcription. Disruption of the putative NF-κB-binding motifs in the GPB5 5′-flanking region silenced the GPB5 activation by p65. Chromatin immunoprecipitation assays revealed that recombinant p65 bound to the predicted NF-κB-binding sites. Because NF-κB is known to associate with acute phase inflammatory cytokines, we examined whether TNFα or IL-1β could regulate GPB5. Both these cytokines activated GPB5 transcription by 2- to 3-fold, and their effects were abolished by the addition of MG132, a NF-κB inhibitor. Our results suggest that inflammatory cytokines positively regulate thyrostimulin through NF-κB activation.

2012 ◽  
Vol 32 (6) ◽  
pp. 531-537 ◽  
Author(s):  
Albert Braeuning ◽  
Silvia Vetter

Photinus pyralis (firefly) luciferase is widely used as a reporter system to monitor alterations in gene promoter and/or signalling pathway activities in vitro. The enzyme catalyses the formation of oxyluciferin from D-luciferin in an ATP-consuming reaction involving photon emission. The purpose of the present study was to characterize the luciferase-inhibiting potential of (E)-2-fluoro-4′-methoxystilbene, which is known as a potent inhibitor of the NF-κB (nuclear factor κB) signalling pathway that is used to modulate the NF-κB signalling pathway in vitro. Results show that (E)-2-fluoro-4′-methoxystilbene effectively inhibits firefly luciferase activity in cell lysates and living cells in a non-competitive manner with respect to the luciferase substrates D-luciferin and ATP. By contrast, the compound has no effect on Renilla and Gaussia luciferases. The mechanism of firefly luciferase inhibition by (E)-2-fluoro-4′-methoxystilbene, as well as its potency is comparable to its structure analogue resveratrol. The in vitro use of trans-stilbenes such as (E)-2-fluoro-4′-methoxystilbene or resveratrol compromises firefly luciferase reporter assays as well as ATP/luciferase-based cell viability assays.


2018 ◽  
Vol 17 (4) ◽  
pp. 1285-1296
Author(s):  
Jae-Woo Park ◽  
Jayoung Oh ◽  
Seok-Jae Ko ◽  
Mun Seog Chang ◽  
Jinsung Kim

In most cancer patients, chemotherapy-induced oral mucositis (OM) is a frequent side effect, leading to low quality of life and delay in therapy. The aim of this study was to evaluate the effects of Onchung-eum, a well-known herbal prescription in traditional medicine comprising 8 herbs that has long been used for skin diseases, on 5-fluorouracil (5-FU)–induced OM in human pharyngeal cells and golden Syrian hamsters. DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, and reactive oxygen species production were measured in vitro. The effects of Onchung-eum on OM of hamster cheek pouches induced by 5-FU were evaluated histologically and using TUNEL assay. In addition, the expression of nuclear factor-κB, caspase-3, and pro-inflammatory cytokines were measured by immunoblotting and immunohistochemistry. Significantly increased cell viability was observed in the Onchung-eum–treated groups compared with the 5-FU–treated control group. In 500 and 1000 mg/kg Onchung-eum–treated groups, the damaged epithelial layers in the cheek pouches of hamsters were significantly recovered. Moreover, at all concentrations, cell death in the cheek pouches of hamsters in the Onchung-eum–treated groups significantly decreased. The expression of pro-inflammatory cytokines, nuclear factor-κB, and caspase-3 also significantly decreased in Onchung-eum–treated groups at 500 and 1000 mg/kg. In conclusion, this study revealed that Onchung-eum can be used to treat chemotherapy-induced OM. However, further studies are required to understand the underlying mechanisms.


2000 ◽  
Vol 348 (3) ◽  
pp. 675-686 ◽  
Author(s):  
Isabelle VAN SEUNINGEN ◽  
Michaël PERRAIS ◽  
Pascal PIGNY ◽  
Nicole PORCHET ◽  
Jean-Pierre AUBERT

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.


2019 ◽  
Vol 20 (5) ◽  
pp. 1241 ◽  
Author(s):  
Bastian Welz ◽  
Rolf Bikker ◽  
Johannes Junemann ◽  
Martin Christmann ◽  
Konstantin Neumann ◽  
...  

To better understand the inflammation-associated mechanisms modulating and terminating tumor necrosis factor (TNF-)induced signal transduction and the development of TNF tolerance, we analyzed both the proteome and the phosphoproteome in TNF long term-incubated (i.e., 48 h) primary human monocytes using liquid chromatography-mass spectrometry. Our analyses revealed the presence of a defined set of proteins characterized by reproducible changes in expression and phosphorylation patterns in long term TNF-treated samples. In total, 148 proteins and 569 phosphopeptides were significantly regulated (103 proteins increased, 45 proteins decreased; 377 peptides with increased and 192 peptides with decreased phosphorylation). A variety of these proteins are associated with the non-canonical nuclear factor κB (NF-κB) pathway (nuclear factor κB (NFKB) 2, v-rel reticuloendotheliosis viral oncogene homolog (REL) B, indolamin-2,3-dioxygenase (IDO), kynureninase (KYNU)) or involved in the negative regulation of the canonical NF-κB system. Within the phosphopeptides, binding motifs for specific kinases were identified. Glycogen synthase kinase (GSK) 3 proved to be a promising candidate, since it targets NF-κB inhibiting factors, such as CCAAT/enhancer binding protein (C/EBP) β. Our experiments demonstrate that both proteome and phosphoproteome analysis can be effectively applied to study protein/phosphorylation patterns of primary monocytes. These results provide new regulatory candidates and evidence for a complex network of specific but synergistically acting/cooperating mechanisms enabling the affected cells to resist sustained TNF exposure and resulting in the resolution of inflammation.


2018 ◽  
Vol 48 (1) ◽  
pp. 339-347 ◽  
Author(s):  
Weiwei Wang ◽  
Lei Yang ◽  
Dan Zhang ◽  
Chao Gao ◽  
Jie Wu ◽  
...  

Background/Aims: Postmenopausal osteoporosis is a common disease associated with estrogen deficiency leading to bone loss and bone tissue changes. The resultant bone fragility and increased risk of fracture has serious adverse effects on health and quality of life of the elderly, making it an important health issue. MicroRNA-218 (miR-218) is closely related to the development of osteoporosis. In this study, we investigated the regulatory mechanisms of miR-218 in osteoclastogenesis. Methods: We investigated miR-218 levels on differentiation of RAW 264.7 cells into osteoclasts compared with normal cells. Next, RAW 264.7 cells were transfected with miR-218 mimics or inhibitors to study the role of miR-218 in osteoclastogenic differentiation. Tartrate-resistant acid phosphatase (TRAP) staining was performed to determine osteoclastogenic differentiation. Bioinformatics analysis and luciferase reporter assay were used to identify and validate miR-218 target genes. Results: miR-218 was downregulated following RAW 264.7 cell differentiation into osteoclasts. miR-218 overexpression attenuated osteoclast differentiation, whereas low miR-218 expression promoted it as demonstrated by increased expression of osteoclast-specific genes and TRAP staining. Bioinformatics analysis and the luciferase reporter assay showed that tumor necrosis factor receptor 1 (TNFR1), a cell membrane receptor of TNF (TNF is an activator of nuclear factor-κB [NF-κB]), is a direct target of miR-218. Conclusions: Our findings indicate that miR-218 regulates osteoclastogenic differentiation negatively by repressing NF-κB signaling by targeting TNFR1, suggesting that targeting miR-218 may be a therapeutic approach in postmenopausal osteoporosis.


2002 ◽  
Vol 367 (3) ◽  
pp. 791-799 ◽  
Author(s):  
Sergio D. CATZ ◽  
Bernard M. BABIOR ◽  
Jennifer L. JOHNSON

The human promoter region of JFC1, a phosphatidylinositol 3,4,5-trisphosphate binding ATPase, was isolated by amplification of a 549bp region upstream of the jfc1 gene by the use of a double-PCR system. By primer extension analysis we mapped the transcription initiation site at nucleotide −321 relative to the translation start site. Putative regulatory elements were identified in the jfc1 TATA-less promoter, including three consensus sites for nuclear factor-κB (NF-κB). We analysed the three putative NF-κB binding sites by gel retardation and supershift assays. Each of the putative NF-κB sites interacted specifically with recombinant NF-κB p50, and the complexes co-migrated with those formed by the NF-κB consensus sequence and p50. An antibody to p50 generated a supershifted complex for these NF-κB sites. These sites formed specific complexes with nuclear proteins from tumour necrosis factor α (TNFα)-treated WEHI 231 cells, which were supershifted with antibodies against p50 and p65. The jfc1 promoter was transcriptionally active in various cell lines, as determined by luciferase reporter assays following transfection with a jfc1 promoter luciferase vector. Co-transfection with NF-κB expression vectors or stimulation with TNFα resulted in significant transactivation of the jfc1 promoter construct, although transactivation of a mutated jfc1 promoter was negligible. The expression of a dominant negative IκB (inhibitor κB) decreased basal jfc1 promoter activity. The cell lines PC-3, LNCaP and DU-145, but not Epstein—Barr virus-transformed lymphocytes, showed a dramatic increase in the expression of JFC1 after treatment with TNFα, suggesting that transcriptional activation of JFC1 by the TNFα/NF-κB pathway is significant in prostate carcinoma cell lines.


2002 ◽  
Vol 364 (2) ◽  
pp. 537-545 ◽  
Author(s):  
Deborah L. BAINES ◽  
Mandy JANES ◽  
David J. NEWMAN ◽  
Oliver G. BEST

Expression of the α-subunit of the amiloride-sensitive sodium channel (αENaC) is regulated by a number of factors in the lung, including oxygen partial pressure (Po2). As transcriptional activation is a mechanism for raising cellular mRNA levels, we investigated the effect of physiological changes in Po2 on the activity of the redox-sensitive transcription factor nuclear factor κB (NF-κB) and transcriptional activity of 5′-flanking regions of the human αENaC gene using luciferase reporter-gene vectors transiently transfected into human adult alveolar carcinoma A549 cells. By Western blotting we confirmed the presence of NF-κB p65 but not p50 in these cells. Transiently increasing Po2 from 23 to 42mmHg for 24h evoked a significant increase in NF-κB DNA-binding activity and transactivation of a NF-κB-driven luciferase construct (pGLNF-κBpro), which was blocked by the NF-κB activation inhibitor sulphasalazine (5mM). Transcriptional activity of αENaC-luciferase constructs containing 5′-flanking sequences (including the NF-κB consensus) were increased by raising Po2 from 23 to 142mm Hg if they contained transcriptional initiation sites (TIS) for exons 1A and 1B (pGL3E2.2) or the 3′ TIS of exon 1B alone (pGL3E0.8). Sulphasalazine had no significant effect on the activity of these constructs, suggesting that the Po2-evoked rise in activity was not a direct consequence of NF-κB activation. Conversely, the relative luciferase activity of a construct that lacked the 3′ TIS, a 3′ intron and splice site but still retained the 5′ TIS and NF-κB consensus sequence was suppressed significantly by raising Po2. This effect was reversed by sulphasalazine, suggesting that activation of NF-κB mediated Po2-evoked suppression of transcription from the exon 1A TIS of αENaC.


2011 ◽  
Vol 92 (7) ◽  
pp. 1561-1570 ◽  
Author(s):  
Chang-Jun Guo ◽  
Wei-Jian Chen ◽  
Li-Qun Yuan ◽  
Li-Shi Yang ◽  
Shao-Ping Weng ◽  
...  

The ankyrin (ANK) repeat is one of the most common protein–protein interaction motifs, found predominantly in eukaryotes and bacteria, but the functions of the ANK repeat are rarely researched in animal viruses, with the exception of poxviruses. Infectious spleen and kidney necrosis virus (ISKNV) is a typical member of the genus Megalocytivirus in the family Iridoviridae and is a causative agent of epizootics in fish. The genome of ISKNV contains four putative viral ANK (vANK) repeat proteins and their functions remain largely unknown. In the present study, it was found that ORF124L, a vANK repeat protein in ISKNV, encodes a protein of 274 aa with three ANK repeats. Transcription of ORF124L was detected at 12 h post-infection (p.i.) and reached a peak at 40 h p.i. ORF124L was found to localize to both the nucleus and the cytoplasm in mandarin fish fry cells. ISKNV ORF124L interacted with the mandarin fish IκB kinase β protein (scIKKβ), and attenuated tumour necrosis factor alpha (TNF-α)- or phorbol myristate acetate (PMA)-induced activity of a nuclear factor κB (NF-κB)–luciferase reporter but did not interfere with the activity of an activator protein 1 (AP-1)–luciferase reporter. Phosphorylation of IκBα and nuclear translocation of NF-κB were also impaired by ISKNV ORF124L. In summary, ORF124L was identified as a vANK repeat protein and its role in inhibition of TNF-α-induced NF-κB signalling was investigated through interaction with the mandarin fish IKKβ. This work may help to improve our understanding of the function of fish iridovirus ANK repeat proteins.


Blood ◽  
2000 ◽  
Vol 95 (1) ◽  
pp. 256-262 ◽  
Author(s):  
D. J. Granville ◽  
C. M. Carthy ◽  
H. Jiang ◽  
J. G. Levy ◽  
B. M. McManus ◽  
...  

The nuclear factor-kappa B (NF-κB) gene transactivator serves in the formation of immune, inflammatory, and stress responses. In quiescent cells, NF-κB principally resides within the cytoplasm in association with inhibitory κ (IκB) proteins. The status of IκB and NF-κB proteins was evaluated for promyelocytic leukemia HL-60 cells treated at different intensities of photodynamic therapy (PDT). The action of the potent photosensitizer, benzoporphyrin derivative monoacid ring A (verteporfin), and visible light irradiation were assessed. At a verteporfin concentration that produced the death of a high proportion of cells after light irradiation, evidence of caspase-3 and caspase-9 processing and of poly(ADP-ribose) polymerase cleavage was present within whole cell lysates. The general caspase inhibitor Z-Val-Ala-Asp-fluoromethylketone (ZVAD.fmk) effectively blocked these apoptosis-related changes. Recent studies indicate that IκB proteins may be caspase substrates during apoptosis. However, the level of IκBβ was unchanged for HL-60 cells undergoing PDT-induced apoptosis. IκB levels decreased during PDT-induced apoptosis, though ZVAD.fmk did not affect this change. At a less intensive level of photosensitization, cellular IκB levels were transiently depressed after PDT. At these times, p50 and RelA NF-κB species were increased within nuclear extracts, as revealed by electrophoretic mobility supershift assays. HL-60 cells transiently transfected with a κB-luciferase reporter construct exhibited elevated luciferase activity after PDT or treatment with tumor necrosis factor-, a well-characterized NF-κB activator. Productive NF-κB activation and associated gene transcription may influence the phenotype and behavior of cells exposed to less intensive PDT regimens. However, IκB is not subject to caspase-mediated degradation as a component of PDT-induced apoptosis. (Blood. 2000;95:256-262)


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