Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P10145 (IL-8)
 23,849 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Reactive oxygen intermediates (ROI), reactive nitrogen intermediates (RNI), and cytokines are frequent companions at sites of acute inflammation. Previous work has established a clear link between the production of cytokines and the subsequent generation of ROI and RNI. However, more recent data indicates that ROI and RNI not only serve as end-stage effector molecules of pathogen destruction and tissue injury, but also as initiators of acute inflammation. Specifically, ROI and RNI will upregulate cytokine gene expression since antioxidants inhibit interleukin 8 (IL-8) production and do not decrease production of other cytokines. Treatment with hydroxyl radical scavengers such as dimethyl sulfoxide (DMSO) will decrease the production of IL-8 in stimulated human whole blood, fibroblasts, type II epithelial cells, and hepatoma cells, but not other cytokines. Addition of exogenous ROI will increase IL-8 production in these same cells. Inhibition of nitric oxide synthase will decrease production of IL-8, whereas addition of nitric oxide (NO)-generating compounds will increase production of IL-8. The hydroxyl radical appears to be the final common pathway of cell activation for IL-8 synthesis, since DMSO will inhibit the NO-driven production of IL-8. Our data indicate that ROI and RNI can serve as intracellular second messengers to induce IL-8 gene expression.
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PMID:Regulation of cytokine gene expression by reactive oxygen and reactive nitrogen intermediates. 861 91

Alpha-Melanocyte-stimulating hormone (MSH) is a potent anti-inflammatory agent in many models of inflammation, suggesting that it inhibits a critical step common to different forms of inflammation. We showed previously that alpha-MSH inhibits nitric oxide (NO) production in cultured macro-phages. To determine how alpha-MSH acts in vivo, we induced acute hepatic inflammation by administering endotoxin (LPS) to mice pretreated with Corynebacterium parvum, alpha-MSH prevented liver inflammation even when given 30 min after LPS administration. To determine the mechanisms of action of alpha-MSH, we tested its influence on NO, infiltrating inflammatory cells, cytokines, and chemokines. Alpha-MSH inhibited systemic NO production, hepatic neutrophil infiltration, and increased hepatic mRNA abundance for TNF alpha, and the neutrophil and monocyte chemokines (KC/IL-8 and MCP-1). We conclude that alpha-MSH prevents LPS-induced hepatic inflammation by inhibiting production of chemoattractant chemokines which then modulate infiltration of inflammatory cells. Thus, alpha-MSH has an effect very early in the inflammatory cascade.
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PMID:Alpha-melanocyte-stimulating hormone reduces endotoxin-induced liver inflammation. 862 92

It was recently demonstrated that nitric oxide (NO) inhalation improves arterial oxygenation in patients with the adult respiratory distress syndrome (ARDS). However, the potential adverse reaction of NO on inflammatory cells and mediators in the lung has not yet been investigated. In this study, we evaluated the impact of NO inhalation on lung polymorphonuclear neutrophil (PMN) activation and proinflammatory cytokine release, both of which are involved in the pathophysiology of ARDS. Two groups of patients with ARDS of similar etiologies were compared; one received NO (n=9) and the other did not (n=5). After 4 d of NO inhalation (18 ppm), PMN form bronchoalveolar lavage (BAL) showed a reduction in both spontaneous H2O2 production (p<0.05) and beta 2 integrin CD11b/CD18 expression (p<0.05). Moreover, the high levels of IL8 and IL-6 decreased in BAL fluid supernatants after NO inhalation (p<0.05). In the NO-untreated group of patients with ARDS, neither PMN activation nor levels of IL-8 and IL-6 in BAL fluid changed significantly on Day 4. These results suggest that NO inhalation might reduce lung inflammation in ARDS, as reflected by PMN activation status and IL-8/IL-6 release.
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PMID:Alveolar neutrophil functions and cytokine levels in patients with the adult respiratory distress syndrome during nitric oxide inhalation. 863 May 84

Nitric oxide synthase (NOS) isoenzymes generate nitric oxide (NO), a sensitive multifunctional intercellular signal molecule. High NO levels are produced by an inducible NOS (iNOS) in activated macrophages in response to proinflammatory agents, many of which also regulate local bone metabolism. NO is a potent inhibitor of osteoclast bone resorption, whereas inhibitors of NOS promote bone resorption both in vitro and in vivo. The possibility that osteoclasts, like macrophages, express a regulated iNOS and produce NO as a potential autocrine signal following inflammatory stimulation was investigated in well-characterized avian marrow-derived osteoclast-like cells. NO production (reflected by medium nitrite levels) was markedly elevated in these cells by the proinflammatory agents lipopolysaccharide (LPS) and the synergistic action of IL-1 alpha, TNF alpha, and IFN gama. inhibitors of NOS activity (aminoguanidine, L-NAME) or iNOS induction (dexamethasone, TGF beta) reduced LPS-stimulated nitrite production. LPS also increased the NOS-associated diaphorase activity of these cells and their reactivity with anti-iNOS antibodies. RT-PCR cloning, using avian osteoclast-like cell RNA and human iNOS primers, yielded a novel 900 bp cDNA with high sequence homology (76%) to human, rat, and mouse iNOS genes. In probing osteoclast-like cell RNA with the PCR-derived iNOS cDNA, a 4.8 kb mRNA species was detected whose levels were greatly increased by LPS. Induction of iNOS mRNA by LPS, or by proinflammatory cytokines, occurred prior to the rise of medium nitrite in time course studies and was diminished by dexamethasone. Moreover, osteoclast-like cells demonstrated an upregulation of NO production and iNOS mRNA by IL-8 and IL-10, regulatory mechanism's not previously described. It is concluded that osteoclast-like cells express a novel iNOS that is upregulated by inflammatory mediators, leading to NO production. Therefore, NO may serve as both a paracrine and autocrine signal for modulating osteoclast bone resorption.
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PMID:Proinflammatory agents, IL-8 and IL-10, upregulate inducible nitric oxide synthase expression and nitric oxide production in avian osteoclast-like cells. 870 87

The combined effects of hypoxia and interleukin 1, lipopolysaccharide, or tumor necrosis factor alpha on the expression of genes encoding endothelial constitutive and inducible nitric oxide synthases, endothelin 1, interleukin 6, and interleukin 8 were investigated in human primary pulmonary endothelial cells and whole pulmonary artery organoid cultures. Hypoxia decreased the expression of constitutive endothelial nitric oxide synthase (NOS-3) mRNA and NOS-3 protein as compared with normoxic conditions. The inhibition of expression of NOS-3 corresponded with a reduced production of NO. A combination of hypoxia with bacterial lipopolysaccharide, interleukin 1 beta, or tumor necrosis factor alpha augmented both effects. In contrast, the combination of hypoxia and the inflammatory mediators superinduced the expression of endothelin 1, interleukin 6, and interleukin 8. Here, we have shown that inflammatory mediators aggravate the effect of hypoxia on the down-regulation of NOS-3 and increase the expression of proinflammatory cytokines in human pulmonary endothelial cells and whole pulmonary artery organoid cultures.
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PMID:Lipopolysaccharide and interleukin 1 augment the effects of hypoxia and inflammation in human pulmonary arterial tissue. 890 7

We investigated the regulation of elastase activity in murine peritoneal macrophages by different cytokines and bacterial LPS. Thioglycolate-elicited mouse peritoneal exudate macrophages secrete a metalloproteinase that degrades elastin. Incubation of peritoneal exudate macrophages with LPS and IFN-gamma significantly inhibited the production of elastase by a mechanism independent of nitric oxide, superoxide, and hydrogen peroxide. The cytokines IL-1alpha, IL-1beta, IL-2, IL-4, IL-6, IL-8, IL-10, TNF, TGF-alpha and -beta, basic fibroblast growth factor, monocyte chemotactic factor-1, and granulocyte CSF (G-CSF) had no significant effect on the production of elastase by macrophages. In contrast, granulocyte-macrophage CSF (GM-CSF) increased the production of elastase in a dose-dependent manner, and with macrophage CSF (M-CSF) inhibited it. Elastin zymography demonstrated that the modulation of elastolytic activity in macrophages was associated with changes in the level of metalloelastase protein. The stimulation of elastase activity by GM-CSF and the inhibition of elastase activity by LPS, IFN-gamma, and M-CSF occurred at the level of transcription. LPS and M-CSF also augmented the expression level of tissue inhibitors of metalloproteinase mRNA. The increased mRNA steady state level of murine macrophage elastase induced by GM-CSF resulted from both increased transcription and enhanced stability. The modulation of metalloelastase activity in macrophages by IFN-gamma, M-CSF, and GM-CSF suggests that these molecules may control the degradation of elastin fibers in lungs or blood vessels.
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PMID:Differential regulation of metalloelastase activity in murine peritoneal macrophages by granulocyte-macrophage colony-stimulating factor and macrophage colony-stimulating factor. 894 20

The function of vascular endothelial cells is to adjust blood vessel tonus, which contributes to maintaining homeostasis within blood vessels. However, inflammatory cytokines are produced in response to invasion by stimulating vascular endothelial cells and sometimes lead to shock or multiple organ failure. In the present study, we assessed cytokines in sepsis and septic shock, and various factors that are said to have a damaging effect on vascular endothelium. Endotoxin was measured by endotoxin-specific methods. Tumor necrosis factor-alpha (TNF-alpha), interleukin 6 (IL-6), and interleukin 8 (IL-8) were measured by enzyme-linked immunosorbent assay (ELISA). Endothelin-I was measured by radioimmunoassay (RIA). Nitric oxide was measured as metabolites of nitrite and nitrate oxides (NOx) by a method based on the Griess method. Thromboxane B2 (TXB2) and 6-keto-prostaglandin F1 alpha (PGF 1 alpha) were both measured by RIA. All of the factors except endotoxin were significantly higher in the septic shock group than in the non-shock group and significantly higher in the non-survivor group than in the survivor group. Significant correlations were also found between endothelin-1 and NOx and between TXB2 and PG1 alpha. Significant correlations were also found between TNF-alpha and IL-6, endothelin-1, NOx and TXB2, but no significant correlations were detected between any of them and endotoxin. In serious diseases such as septic shock, the vascular endothelial constricting factors, endothelin and TXB2, and the blood vessel relaxing factors NOx and PGF1 alpha increase almost simultaneously. This suggests that the body's regulating mechanisms are disrupted in these serious conditions. The results of this study also suggest that inflammatory cytokines may be involved in stimulating the production of these factors.
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PMID:Functional modification of vascular endothelial cells by cytokines during septic shock. 894 12

While the regulation of nitric oxide (NO) by inflammatory cytokines or lipopolysaccharide (LPS) has received considerable attention, NO modulation of cytokine expression has yet to be fully explored. The NO synthase inhibitor, NG-nitro-L-arginine methyl ester (L-NAME), inhibited interleukin (IL)-8 and IL-6 production in LPS-stimulated human whole blood in a dose-dependent manner. In the presence of 1 microgram/mL LPS, L-NAME blocked IL-8 release (72 +/- 4% inhibition at 20 mM (mean +/- SEM, p < .05)) 24 h post-LPS without affecting cellular viability. IL-6 production was significantly inhibited only with the highest dose of L-NAME used. L-NAME inhibition of IL-8 production was also observed at the mRNA level. Conversely, direct exposure of whole blood to NO with the spontaneous NO liberator DETA NONOate caused a dose-dependent stimulation of IL-8, but had no effect on IL-6 release. IL-8 concentrations rose from 8.3 +/- 1.9 ng/mL at 24 h to 31.7 +/- 7.6 ng/mL at 72 h with a single stimulation of 10 mM DETA NONOate. The hydroxyl radical scavenger dimethyl sulfoxide (DMSO) prevented the DETA NONOate induction of IL-8, suggesting the participation of the hydroxyl radical in the NO-induced IL-8 production. These results provide important evidence substantiating a role for NO as a regulator of cytokine expression.
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PMID:Nitric oxide regulation of interleukin-8 gene expression. 898 33

The aim of the present study was to investigate the relationship between the levels of pro-inflammatory [interleukin 6 (IL-6), IL-8, tumour necrosis factor alpha (TNF-alpha)], anti-inflammatory cytokines [IL-10, soluble TNF receptor type I (TNFsrI), TNFsrII], and the production of nitric oxide (NO) during a 1-week period in 23 patients with severe sepsis. The highest levels of pro-inflammatory cytokines and nitrate, the stable metabolite of NO, were found during the first day after inclusion and gradually declined thereafter. Detectable levels of IL-10, TNFsrI and TNFsrII were present in all patients at study entry but did not significantly change during the study period [analysis of variance (MANOVA); P > 0.05]. Serum nitrate levels correlated significantly with both pro-inflammatory cytokines (IL-6, IL-8, TNF-alpha) as well as anti-inflammatory cytokines (IL-10, TNFsrI, TNFsrII). Serum nitrate levels over time were higher in patients with positive blood cultures (n = 4) (MANOVA; P < 0.005), as compared to patients without proven bacteraemia. These data support the concept of an acute phase of sepsis that is characterized by an excess of pro-inflammatory cytokines, while anti-inflammatory cytokines are predominantly present during the secondary phase. The present findings indicate that pro-inflammatory cytokines are related to the induction of excessive NO production during the first phase of sepsis and that reduction of NO production occurs during the secondary phase. This may suggest that anti-inflammatory cytokines are able to diminish the production of NO in patients with severe sepsis.
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PMID:Relation between pro- and anti-inflammatory cytokines and the production of nitric oxide (NO) in severe sepsis. 907 65

Interleukin-8 (IL-8) and nitric oxide (NO) may be important mediators in the pathogenesis of chronic idiopathic inflammatory bowel disease (CIIBD), but their roles in disease activity in ulcerative colitis (UC) and Crohn's disease (CD) are uncertain. The aim of this study was to measure mRNA for IL-8 and inducible NO synthase (iNOS) in small mucosal biopsies from untreated patients at first presentation and to relate these measurements to the histological levels of polymorph infiltration graded on a ten-point scale. For this purpose, a sensitive enzyme-linked oligonucleotide chemiluminescent assay (ELOCA) was developed to quantitate reverse transcription-polymerase chain reaction (RT-PCR) products amplified from RNA from paired biopsy samples. The levels of IL-8 and iNOS mRNAs were calculated as ratios of the RT-PCR products to glyceraldehyde-3-phosphate dehydrogenase (GAPDH) RT-PCR product. In UC patients, median values of IL-8/GAPDH and iNOS/GAPDH were significantly elevated compared with controls and CD. However, in both UC and CD, the IL-8/GAPDH and iNOS/GAPDH ratios correlated significantly with polymorph infiltration. ELOCA enabled quantitation of multiple mRNAs in small mucosal biopsies from untreated patients with CIIBD and supported a role for IL-8 and iNOS in acute inflammation in both UC and CD.
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PMID:Interleukin-8 and inducible nitric oxide synthase mRNA levels in inflammatory bowel disease at first presentation. 907 8


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