Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P05231 (interleukin-6)
 23,907 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Prostaglandins are involved in mediating several important processes in mammalian reproduction, including the initiation of parturition. In the present study, we examined the expression in the rat uterus of two-rate limiting enzymes involved in prostaglandin production, cyclooxygenase (COX) 1 and 2. Expression of the COX-2 gene in the pregnant rat uterus gave rise to a single mRNA transcript of approximately 4.4 kb. COX-2 mRNA levels increased 3.5 fold between day 7 of pregnancy and the onset of parturition on day 22. In contrast, COX-1 mRNA levels remained constant during the same period. To investigate factors involved in mediating the regulation of COX-1 and COX-2 gene expression, rat endometrial stromal and epithelial cell lines, were used. In the stroma-derived cell line, CUS-V2, COX-2 gene expression was demonstrated by reverse transcriptase/polymerase chain reaction (RT-PCR) and by immunocytochemistry. In these cells, COX-2 gene expression was inducible by the cytokines interleukin-1 beta and tumor necrosis factor alpha, but not by interleukin-6. The two former cytokines also induced prostaglandin F2 alpha production. In contrast, COX-1 gene expression was constitutive in this cell line. In the endometrial epithelium-derived cell line, CUE-P both COX-1 and COX-2 genes were expressed in a constitutive fashion. In conclusion, the present in vivo and in vitro data indicate that decidual COX-2, but not COX-1, gene expression is regulated during pregnancy and implicate specific cytokines as possible inducers within the decidua.
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PMID:Regulation of COX-2 gene expression in rat uterus in vivo and in vitro. 897 7

It has been suggested that microgravity alters bone metabolism. Evidence for this phenomenon includes the negative calcium balance and decreased bone density in astronauts, as well as, inhibition of bone formation in rats flown for 2 to 3 weeks. However, the specific mechanisms that modulate these changes in microgravity are unknown. The purpose of this study was to clarify the mechanism of microgravity-induced bone demineralization using normal rat osteoblasts obtained from femur marrow cultures. The osteoblasts were cultured for 5 days during a Shuttle-Spacelab flight (STS-65). After collection of the culture medium, the cellular DNA and RNA were fixed on board. Enzyme-immunoassay of the culture medium for prostaglandin E2 (PGE2) indicated that microgravity induced a 4.5- to 136-fold increase in flight samples as compared to the ground control cultures. This increase of PGE2 production was consistent with a 3.3- to 9.5-fold elevation of inducible prostaglandin G/H synthase-2 (PGHS-2) mRNA, quantitated by reverse transcription-polymerase chain reaction (RT-PCR). The mRNA induction for the constitutive isozyme PGHS-1 was less than that for PGHS-2. The interleukin-6 (IL-6) mRNA was also increased (6.4- to 9.3-fold) in microgravity as compared to the ground controls. Since PGE2 and IL-6 are both known to play a role in osteoclast formation and bone resorption, these data provide molecular mechanisms that contribute to our understanding of microgravity-induced alterations in the bone resorption process.
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PMID:Microgravity induces prostaglandin E2 and interleukin-6 production in normal rat osteoblasts: role in bone demineralization. 898 71

Interleukin-6 (IL-6) induces osteoclast-like cell (osteoclast) formation in a dose-dependent fashion in cocultures of mouse bone marrow cells and osteoblastic cells when soluble IL-6 receptor (sIL-6R) is present. Simultaneous treatment with submaximal doses of IL-1alpha and IL-6 with sIL-6R caused marked induction of osteoclast formation and PGE2 synthesis. These effects were suppressed by adding neutralizing antibodies against IL-1alpha or IL-6R and were totally abolished by adding nonsteroidal antiinflammatory drugs, such as indomethacin and a selective cyclooxygenase-2 (COX-2) inhibitor (NS398). In mouse osteoblastic cells, both IL-1alpha and IL-6 with sIL-6R markedly induced messenger RNA expression of COX-2, but not COX-1, as determined by Northern blot analysis, and luciferase activity in cells stably transfected with a COX-2 promoter-luciferase fusion construct. IL-6 and sIL-6R, when added separately, did not stimulate COX-2 messenger RNA expression. Simultaneous addition of IL-1alpha and IL-6 with sIL-6R to osteoblast cultures cooperatively induced transcription of COX-2, which was associated with a marked increase in COX activity measured by the conversion of arachidonic acid into PGE2. The increased PGE2 synthesis by osteoblasts may play an important role in osteoclastogenesis induced by submaximal doses of IL-1 and IL-6.
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PMID:Transcriptional induction of cyclooxygenase-2 in osteoblasts is involved in interleukin-6-induced osteoclast formation. 916 25

The aim of this study was to investigate the influence of the acute-phase response and the proinflammatory cytokines on the transcription of the genes encoding the limiting enzymes for the production of prostaglandins, cyclooxygenase (COX)-1 and COX-2, in the rat brain. The bacterial endotoxin lipopolysaccharide (intravenous and intraperitoneal) and turpentine (intramuscular) were used as different models of inflammation in adult male rats. Animals were also killed at various times after intravenous administration of interleukin-1beta, tumor necrosis factor-alpha, and interleukin-6, and mRNAs encoding COX-1 and COX-2 were assayed by in situ hybridization histochemistry. A profound transcriptional activation of the gene encoding COX-2 was detected over blood vessels of the entire brain microvasculature, choroid plexus, and leptomeninges of lipopolysaccharide-challenged rats. Injection of the endotoxin intravenously also increased COX-2 gene expression within parvocellular division of the hypothalamic paraventricular nucleus. It is interesting that intramuscular turpentine injection stimulated transcription of COX-2 along endothelium of brain capillaries, and the signal of this transcript paralleled the inflammation of the left hind limb. A robust COX-2 mRNA signal was detected rapidly in the brain microvessels of interleukin-1beta-injected rats, whereas tumor necrosis factor-alpha administration caused a modest but significant induction of this transcript. In contrast, intravenous injection of interleukin-6 did not alter genetic expression of COX-2, and none of the above described models affected the synthesis of COX-1 gene in the rat brain. These results indicate that specific cell populations, in particular vascular- and/or perivascular-associated cells, are responsible for the central production of prostaglandins during systemic inflammation, and circulating interleukin-1beta is likely to be a potent mediator of this response.
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PMID:Effect of acute systemic inflammatory response and cytokines on the transcription of the genes encoding cyclooxygenase enzymes (COX-1 and COX-2) in the rat brain. 945 38

Cyclooxygenase (COX)-2 levels are elevated in several types of human cancer tissues. Nonselective nonsteroidal anti-inflammatory drugs (NSAIDs) inhibit both the COX-1 and COX-2 protein, the two enzymes that convert arachidonic acids to prostaglandins. Regular use of such NSAIDs significantly reduces the risk and spread of some cancers. The objective of this study was to elucidate the molecular pathology of neoplasms that overexpress COX-2. Epidemiological data and clinical studies were analyzed and compared with results of studies of human tumor tissues, animal models, and cultured tumor cells. COX-2, but not COX-1, is highly expressed in human colon carcinoma, squamous cell carcinoma of the esophagus, and skin cancer. COX-2 is inducible by oncogenes ras and scr, interleukin-1, hypoxia, benzo[a]pyrene, ultraviolet light, epidermal growth factor, transforming growth factor beta, and tumor necrosis factor alpha. Dexamethasone, antioxidants, and tumor-suppressor protein p53 suppress COX-2 expression. COX-2 synthesizes prostaglandin E2 (PGE2) which stimulates bcl-2 and inhibits apoptosis, and induces interleukin-6 (IL-6) which enhances haptoglobin synthesis. PGE2 is associated with tumor metastases, IL-6 with cancer cell invasion, and haptoglobin with implantation and angiogenesis. Drastic reduction in polyp number results from COX-2 gene knockout as well as from selective COX-2 inhibition in a mouse model of human familial adenomatous polyposis. Nonselective NSAIDs, for instance aspirin, and selective COX-2 inhibitors such as celecoxib (SC-58635) and NS-398 suppress azoxymethane-induced colon carcinogenesis in rats. Aspirin, indomethacin, and ibuprofen decrease cultured lung cancer cell proliferation. Selective inhibition of COX-2 is preferable to nonselective inhibition. It reduces cancer cell proliferation, induces cancer cell apoptosis, and spares COX-1-induced cytoprotection of the gastrointestinal tract.
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PMID:Molecular pathology of cyclooxygenase-2 in neoplasia. 1067 79

Tumour necrosis factor (TNF)-alpha-stimulated prostaglandin (PG) E(2)biosynthesis by amnion-derived AV3 cells is accompanied by increased prostaglandin H synthase (PGHS)-2 mRNA expression. PGHS-1 mRNA expression is unchanged. PGHS-2 promoter-reporter constructs (-891/+9 and 5' deletions thereof) were prepared. The regions containing concensus nuclear factor kappaB (NF-kappaB) elements (-447/-438 and -222/-213) did not enhance promoter activity. Elements associated with both basal and TNF-alpha-stimulated expression lie between bases -52 and -203. Site-directed mutagenesis of nuclear factor of interleukin-6 (NF-IL6) and cyclic AMP response elements (CREs) in this region reduced both basal and induced transcriptional activity of the -203/+9 construct by over 95 per cent. Electrophoretic mobility-shift assays using oligonucleotides derived from these sites demonstrated formation of specific DNA-protein complexes. Both NF-IL6 and CRE unlabelled oligonucleotides inhibited complex formation with the NF-IL6 oligonucleotide probe. Unlabelled CRE oligonucleotide also effectively inhibited formation of the complex with the CRE probe, but reduced effectiveness was observed when the NF-IL6 oligonucleotide was the competitor. Finally, unlabelled, consensus NF-kappaB oligonucleotide failed to compete for either probe. TNF-alpha treatment did not increase levels of these complexes. Thus NF-kappaB does not enhance basal or TNF-alpha-responsive PGHS-2 transcription in amnion-derived AV-3 cells. A permissive role for NF-IL6/CRE binding proteins in regulating PGHS-2 expression in these cells is indicated, but requires further clarification.
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PMID:Tumour necrosis factor-alpha regulation of prostaglandin H synthase-2 transcription is not through nuclear factor-kappaB in amnion-derived AV-3 cells. 1109 28

Bacterial lipopolysaccharide (LPS) is a risk factor for exacerbation of asthma and causes airway inflammation. The aim of this study was to examine the effects of disruption of prostaglandin (PG) H synthase (PGHS)-1 and PGHS-2 genes on pulmonary responses to inhaled LPS. PGHS-1(-/-), PGHS-2(-/-), and wild-type (WT) mice were exposed to 4 to 6 microg/m(3) LPS via aerosol. Enhanced pause (PenH), a measure of bronchoconstriction, was assessed using a whole-body plethysmograph before and immediately after a 4-h LPS exposure. Bronchoalveolar lavage (BAL) was performed after LPS exposure to assess inflammatory cells, cytokines/chemokines (tumor necrosis factor-alpha, interleukin-6, and macrophage inflammatory protein-2), and PGE(2). The degree of lung inflammation was scored on hematoxylin-and-eosin-stained sections. PGHS-1 and PGHS-2 protein levels were determined by immunoblotting. All mice exhibited increased PenH and methacholine responsiveness after LPS exposure; however, these changes were much more pronounced in PGHS-1(-/-) and PGHS-2(-/-) mice relative to WT mice (P < 0.05). There were no significant differences in inflammation as assessed by BAL fluid (BALF) cells or lung histology between the genotypes despite reduced BALF cytokines/chemokines and PGE(2) in PGHS-1(-/-) and PGHS-2(-/-) mice relative to WT mice (P < 0.05). PGHS-2 was upregulated more in PGHS-1(-/-) mice compared with WT mice after LPS exposure. We conclude that: (1) airway inflammation and hyperresponsiveness are dissociated in PGHS-1(-/-) and PGHS-2(-/-) mice exposed to LPS; (2) the balance of PGHS-1 and PGHS-2 is important in regulating the functional respiratory responses to inhaled LPS; and (3) neither PGHS-1 nor PGHS-2 is important in regulating basal lung function or the inflammatory responses of the lung to inhaled LPS.
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PMID:Airway inflammation and responsiveness in prostaglandin H synthase-deficient mice exposed to bacterial lipopolysaccharide. 1169 51

Neuroinflammation is a central feature of Alzheimer disease (AD). It involves an innate immune reaction of sufficient intensity that self attack on neurons occurs. This phenomenon is best described as autotoxicity to distinguish it from classical autoimmunity which involves cloning of peripheral lymphocytes. Many compounds have been identified in AD brain which are known to promote and sustain inflammatory responses. They include beta-amyloid protein; the pentraxins C-reactive protein and amyloid P; complement proteins; the inflammatory cytokines interleukin-1, interleukin-6 and tumor necrosis factor-alpha; the protease inhibitors alpha-2-macroglobulin and alpha-1-antichymotrypsin; and the prostaglandin generating cyclooxygenases COX-1 and COX-2. Orally effective agents which can counteract the influence of these inflammatory stimulators should be effective in treating AD. Epidemiological evidence, coupled with results from pilot clinical trials, suggest there is great promise for traditional COX-1 inhibiting NSAIDs. Inhibitors of mediators closer to the core processes might offer even greater therapeutic promise. Some theoretical opportunities are suggested, based on intervention in the action of the above mentioned mediators.
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PMID:Inflammation, autotoxicity and Alzheimer disease. 1175 86

Anorexia and weight loss are frequent complications of acute and chronic infections and result from induction of cytokines, prostaglandins, and other inflammatory mediators that are critical for pathogen elimination. Selective attenuation of the hypophagic response to infection and maintenance of the production of factors essential for infection control would be a useful addition to antimicrobial therapy in the treatment of human disease. Here, we evaluate the relative contribution of cyclooxygenase (COX)-1- and COX-2-derived prostaglandins to anorexia and weight loss precipitated by systemic immune activation by lipopolysaccharide (LPS). Using COX isoform-selective pharmacological inhibitors and gene knockout mice, we found that COX-2 inhibition during LPS-induced inflammation results in preserved food intake and maintenance of body weight, whereas COX-1 inhibition results in augmented and prolonged weight loss. Regulation of neuropeptide Y, corticotropin-releasing hormone, leptin, and interleukin-6 does not change as a function of COX-2 inhibition after LPS administration. Our data implicate COX-2 inhibition as a therapeutic target to maintain nutritional status while still allowing a normal cytokine response during infection.
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PMID:COX-2 inhibition attenuates anorexia during systemic inflammation without impairing cytokine production. 1183 69

Salix extracts are in current use for the treatment of pain and inflammation. In order to obtain an insight into the mechanism(s) of action of the ethanolic Salix extract 1520L--which is essentially similar to an extract for which clinical studies have demonstrated analgesic effectiveness--its effects were evaluated in an established in vitro assay test system using primary human monocytes. The IC50-values obtained for the inhibition of lipopolysaccharide (LPS)-induced release of prostaglandin E2 (PGE2) reflecting cyclooxygenase (COX)-2-mediated PGE2 release were 47 microg/ml and 0.6 microg/ml, for the Salix extract 1520L and rofecoxib-like research compound L745337, respectively. There was no effect on COX-1 and COX-2 activity. The Salix extract inhibited the LPS-induced release of tumor necrosis factor-alpha, interleukin-1beta and interleukin-6 with IC50-values of 180.0, 33.0 and 86.0 microg/ml, respectively. Both, salicin and salicylate, had no effect in any of the parameters. Our results indicate that Salix extract 1520L inhibits COX-2-mediated PGE2 release through compounds other than salicin or salicylate. Our data further suggest that the proprietary Salix extract is a weak inhibitor of proinflammatory cytokines.
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PMID:Effects of an ethanolic salix extract on the release of selected inflammatory mediators in vitro. 1507 Jan 63


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