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Query: UNIPROT:P05231 (
interleukin-6
)
23,907
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Interleukin-6
(
IL-6
) and gamma interferon (IFN-gamma) induce a partially overlapping set of genes, including the genes for interferon regulatory factor 1 (IRF-1), intercellular adhesion molecule 1 (ICAM-1), and the acute-phase protein alpha 2-macroglobulin. We report here that the rat alpha 2-macroglobulin promoter is activated by IFN-gamma in human hepatoma (HepG2) cells and that the IFN-gamma response element maps to the same site previously defined as the acute-phase response element (APRE), which binds the
IL-6
-activated transcription factor APRF (acute-phase response factor). As was reported for fibroblasts, the IFN-gamma-regulated transcription factor GAF is phosphorylated at tyrosine after IFN-gamma treatment of HepG2 cells. IFN-gamma posttranslationally activates a protein which specifically binds to the alpha 2-macroglobulin APRE. This protein is shown to be identical or closely related to GAF. Although APRF and GAF are shown to represent different proteins, their binding sequence specificities are very similar. APRF and GAF bind equally well to the APRE sequences of various acute-phase protein genes as well as to the IFN-gamma response elements of the IRF-1, ICAM-1, and other IFN-gamma-inducible genes. Transient transfection analysis revealed that the IFN-gamma response elements of the IRF-1 and ICAM-1 promoters are able to confer responsiveness to both IFN-gamma and
IL-6
onto a heterologous promoter. Therefore, APRF and GAF are likely to be involved in the transcriptional induction of these immediate-early genes by
IL-6
and IFN-gamma, respectively. Taken together, these results demonstrate that two functionally distinct hormones,
IL-6
and IFN-gamma, act through common regulatory elements to which different transcription factors sharing almost the same sequence specificity bind.
Mol
Cell Biol 1994 Mar
PMID:The signalling pathways of interleukin-6 and gamma interferon converge by the activation of different transcription factors which bind to common responsive DNA elements. 750 45
The human glycoprotein hormone alpha-gene is transcriptionally activated by cAMP in placental cells. We have shown that the novel hypothalamic peptide, pituitary adenylate cyclase activating polypeptide, PACAP-38, significantly stimulates intracellular cAMP levels (12-fold increase; P < 0.001) in JEG-3 choriocarcinoma cells. Regulation of alpha-promoter activity was assessed using both the chloramphenicol acetyl transferase (CAT) and the luciferase (LUC) reporter gene systems. alpha-CAT activity was significantly stimulated by PACAP-38 (4-fold increase; P < 0.05) at 24 h with a similar stimulation being seen with a LUC expression vector. The kinetics of stimulation of the alpha-promoter by PACAP-38 were similar to those seen with 8-Br-cAMP and vasoactive intestinal polypeptide (VIP), a peptide which shares 68% homology with PACAP-38. PACAP-38 also stimulated the production of
IL-6
from JEG-3 cells with a time course of response similar to that of alpha-promoter transcription. We conclude that human placental choriocarcinoma cells possess functional receptors for PACAP-38, whose activation enhances cAMP formation, alpha-subunit gene transcription and
interleukin-6
(
IL-6
) production.
Mol
Cell Endocrinol 1994 Feb
PMID:PACAP-38 positively regulates glycoprotein hormone alpha-gene expression in placental cells. 751 49
We have studied transcription factors that are coupled to the activation of cytokine receptors in liver and in mammary epithelial cells.
Interleukin-6
(
IL-6
) causes the rapid activation of the acute-phase response factor (APRF) in the liver of animals during acute inflammation and in cultured human hepatoma cells (HepG2) and induces the transcription of the acute-phase protein genes, e.g. alpha 2-macroglobulin (alpha 2-M). In the mammary gland and in cultured HC11 mammary epithelial cells, milk protein genes, e.g. beta-casein, are induced by the lactogenic hormones, insulin, glucocorticoids, and PRL. The induction of the beta-casein gene promoter is preceded by the activation of the mammary gland factor (MGF). We have compared the DNA binding sequences of APRF and MGF, 5'-CTTCTT/GGGAATT-3', and have found that they coincide in 11 of 12 positions. Bandshift experiments and oligonucleotide competition experiments showed that both factors, MGF and APRF, are able to bind to the
IL-6
response element of the alpha 2-M gene promoter and to the lactogenic hormone response element of the beta-casein gene promoter with very similar specificities. Partial proteolytic digestion of APRF and MGF DNA complexes yielded similar clipping patterns. The UV cross-linked DNA complexes of both transcription factors were of the same apparent molecular mass.
IL-6
activation of APRF in HepG2 cells can be observed within minutes. MGF induction by PRL in HC11 cells occurs with similar kinetics. The synergistic action of glucocorticoids and PRL is necessary for the induction of the beta-casein gene, but PRL is sufficient for MGF activation.(ABSTRACT TRUNCATED AT 250 WORDS)
Mol
Endocrinol 1994 Apr
PMID:Mammary gland factor activated by prolactin on mammary epithelial cells and acute-phase response factor activated by interleukin-6 in liver cells share DNA binding and transactivation potential. 751 23
Epidermal keratinocytes (EK) are exposed to multiple inflammatory stimuli and paracrine factors secreted by various dermal cells (lymphocytes, mast-cells, macrophages, fibroblasts) during wounding, cutaneous allergy and infections. We have previously demonstrated that following stimulation with interleukin-4 (IL-4) or interferon-gamma, human EK express the low affinity receptor for IgE (Fc epsilon RII/CD23) on their surface. In the present study, we showed that the ligation of CD23 by IgE/anti-IgE immune complexes or specific monoclonal antibody, induces a dose-dependent release of
interleukin-6
and tumor necrosis factor-alpha from EK. CD23-ligation activates the nitric oxide-dependent pathway, as demonstrated by the high levels of nitrites released in cell supernatants, and the accumulation of intracellular cyclic nucleotides in EK. These second messengers are required for IgE-dependent stimulation of cytokine production by these cells, as this is completely abolished by cAMP or NO synthase antagonists. Human epithelial keratinocytes may thus participate in IgE-mediated immune responses, through their ability to express functional CD23 antigen.
Cell
Mol
Biol (Noisy-le-grand) 1994 May
PMID:IgE-dependent activation of Fc epsilon RII/CD23+ normal human keratinocytes: the role of cAMP and nitric oxide. 924 2
Based on a suspected role of the immune system in the pathophysiology of Alzheimer's disease (AD) and the new discoveries of neuroimmune networks, the investigation of certain neuroimmune markers was performed in AD patients, healthy controls, and disease controls. In agreement with our previous immunological research on AD, the assessment of additional immune parameters revealed abnormalities of both cellular and humoral immunity in several AD patients. These include: 1. Enhanced production of cytokines, such as interleukin-1 (IL-1), interleukin-2 (IL-2), and
interleukin-6
(
IL-6
); 2. Increase plasma level of CD8-positive lymphocyte derived soluble CD8 (sCD8) antigen; and 3. Increased incidence of autoantibodies to brain myelin basic protein (MBP) and thymic cells. As analyzed by flow cytometry and enzyme immunoassay, the peripheral blood immunocytes from AD patients showed a significant increase in the expression of the brain-derived S-100 protein. In the cell proliferation assay, the blood immunocytes from healthy subjects responded to stimulation with beta-amyloid protein (beta AP), but this response was absent in AD patients. The initial results of our research suggest that the studies of specific markers of the neuroimmune axis may be potentially important for the new development of diagnostic and therapeutic strategies for AD.
Mol
Neurobiol
PMID:Studies of neuroimmune markers in Alzheimer's disease. 753 89
Human endometria were analysed for the synthesis and secretion of proteins following short term culture of human endometrial tissue in the presence of 35S-methionine. During the menstrual cycle secretory proteins of molecular weight (MW) 30, 35, 45, 50, 59, 74, 97 and 135 kDa showed increased synthesis during the proliferative phase. The synthesis of these proteins decreased in the secretory phase but the induction of a
26 kDa protein
in the early secretory phase and a 28 kDa protein in the late secretory phase was observed. The synthesis of the above secretory proteins of the human endometrium was also confirmed by two dimensional gel electrophoresis. Further, the results demonstrated that the secretory protein profile of human decidual endometria and endometria exhibiting irregular ripening was identical to that of normal secretory phase endometria. But, endometria exhibiting hyperplasia, cystic glandular hyperplasia and adenomatous glandular hyperplasia presented similar secretory protein profiles which were identical with the secretory protein profile of normal proliferative phase endometrium. The present study confirms that a number of proteins are synthesised by the human endometrium during the normal menstrual cycle and during pregnancy. It also provides data for the first time on the proteins secreted by the endometria exhibiting irregular ripening, hyperplasia, cystic glandular hyperplasia and adenomatous glandular hyperplasia.
Cell
Mol
Biol (Noisy-le-grand) 1995 Jun
PMID:Synthesis and secretion of proteins by the human proliferative, secretory, decidual and hyperplastic endometrium. 754 92
A state of severe bone loss is often observed in patients and animals suffering from phosphate (Pi) depletion. Conversely, Pi surfeit may have an anabolic effect on bone and may antagonize bone resorption. To study whether Pi has a direct effect on the production of the bone-resorbing
interleukin-6
(
IL-6
) by osteoblasts, we cultured MC3T3-E1, UMR-106, and isolated rat calvaria cells in media containing varying concentrations of Pi (0-3 mM) and measured the production of
IL-6
released into the media.
IL-6
production was steady with time and was stimulated by parathyroid hormone, 1,25-dihydroxyvitamin D3, and interleukin-1 alpha. However,
IL-6
production did not change with varying Pi concentrations. We concluded that the
IL-6
production by osteoblastic cells is independent of the medium Pi.
Biochem
Mol
Med 1995 Aug
PMID:Production of interleukin-6 by osteoblastic cells is independent of medium inorganic phosphate. 758 75
Ozone (O3) is one of the major irritant oxidant gases in photochemical smog. In the present study, the in vitro effect of low concentrations of O3 (0.1 to 1 ppm) was evaluated on cell viability and cytokine secretion by alveolar macrophages (AM) from guinea pigs and healthy subjects. Cell injury was estimated immediately after O3 exposure by evaluation of ATP cell content (measured by bioluminescence) and lactic dehydrogenase (LDH) release in the culture medium. No cytotoxic effect was found: the ATP cell content of both guinea pig AM and human AM did not significantly change after O3 exposure and similarly the LDH release in the culture medium was unchanged. AM-derived cytokines (tumor necrosis factor alpha [TNF alpha], interleukin-1 beta [IL-1 beta],
interleukin-6
[IL-6], and interleukin-8 [IL-8]) were evaluated in AM supernatants. O3 exposure was associated with a significant increase in cytokine secretion, with a peak value at 0.4 ppm O3. The exposure of the guinea pig AM to 0.4 ppm O3 for 60 min increased the IL-6 activity by 252 +/- 60% and TNF activity by 202 +/- 35%. The increase in monokine production by the human AM was 443 +/- 208% for TNF alpha, 484 +/- 171% for IL-1 beta, 383 +/- 147% for IL-6, and 226 +/- 45% for IL-8 after a 60-min exposure to 0.4 ppm O3. Lowest O3 concentrations (0.1 and 0.2 ppm) only increased TNF alpha secretion.(ABSTRACT TRUNCATED AT 250 WORDS)
Am J Respir Cell
Mol
Biol 1995 Jul
PMID:Ozone stimulates synthesis of inflammatory cytokines by alveolar macrophages in vitro. 759 38
Interleukin-6
(
IL-6
) is known to be a major mediator of the acute-phase response in liver. We show here that
IL-6
triggers the rapid activation of a nuclear factor, termed acute-phase response factor (APRF), both in rat liver in vivo and in human hepatoma (HepG2) cells in vitro. APRF bound to
IL-6
response elements in the 5'-flanking regions of various acute-phase protein genes (e.g., the alpha 2-macroglobulin, fibrinogen, and alpha 1-acid glycoprotein genes). These elements contain a characteristic hexanucleotide motif, CTGGGA, known to be required for the
IL-6
responsiveness of these genes. Analysis of the binding specificity of APRF revealed that it is different from NF-IL6 and NF-kappa B, transcription factors known to be regulated by cytokines and involved in the transcriptional regulation of acute-phase protein genes. In HepG2 cells, activation of APRF was observed within minutes after stimulation with
IL-6
or leukemia-inhibitory factor and did not require ongoing protein synthesis. Therefore, a preexisting inactive form of APRF is activated by a posttranslational mechanism. We present evidence that this activation occurs in the cytoplasm and that a phosphorylation is involved. These results lead to the conclusions that APRF is an immediate target of the
IL-6
signalling cascade and is likely to play a central role in the transcriptional regulation of many
IL-6
-induced genes.
Mol
Cell Biol 1993 Jan
PMID:Acute-phase response factor, a nuclear factor binding to acute-phase response elements, is rapidly activated by interleukin-6 at the posttranslational level. 767 52
Using two different cell systems, we show that the cytoplasmic domain of the granulocyte-colony-stimulating factor receptor (G-CSFR) may be composed of at least two functional regions. The first, within the membrane-proximal 57 amino acids, is absolutely required to deliver a proliferative signal. This region contains two sequence motifs conserved between members of the hematopoietin receptor family. The second functional region resides between amino acids 57 and 96. This region is required for the induction of acute-phase plasma protein gene expression when the G-CSFR is transfected into human hepatoma cell lines. The G-CSFR-transfected hepatoma cells respond to G-CSF by increasing the production of the same set of plasma proteins as stimulated by
interleukin-6
, suggesting that the two cytokines share a common signal transduction pathway.
Mol
Cell Biol 1993 Apr
PMID:Distinct regions of the human granulocyte-colony-stimulating factor receptor cytoplasmic domain are required for proliferation and gene induction. 768 Nov 46
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