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)

A proinflammatory cytokine cascade, including IL-1 alpha, IL-1 beta, TNF-alpha, IL-6, and IL-8, is activated in response to infection or immunologic insult. Besides their immunologic effects, several of these mediators stimulate bone resorption and inhibit bone formation. Osteocalcin, the most abundant noncollagenous protein present in bone, is an osteoblast-specific product whose production closely correlates with bone formation, and which has also been implicated in control of bone resorption. IL-1 and TNF have previously been shown to down-regulate osteocalcin production in vitro and in vivo, although the mechanism of this inhibition is unknown. In the present studies, IL-1 beta and TNF-alpha both inhibited 1,25-dihydroxyvitamin D3-stimulated production of osteocalcin protein and mRNA by ROS 17/2.8 osteosarcoma cells, whereas IL-6 had no effect on protein and only weakly inhibited mRNA. To determine if down-regulation was exerted at the transcriptional level, an osteocalcin promoter-chloramphenicol acetyltransferase (CAT) fusion gene was constructed (PHOC-CAT). After transient transfection of PHOC-CAT into ROS 17/2.8 osteosarcoma cells, reporter CAT activity was up-regulated by vitamin D at concentrations above 10(-12) M. In screening studies, TNF-alpha (-57%) and IL-6 (-37%) inhibited vitamin D-stimulated osteocalcin transcription, whereas IL-1 alpha, IL-1 beta, and IL-8 had no effect. Other immune cytokines and growth factors, including IL-2, IL-3, IL-7, and M-CSF, also failed to regulate osteocalcin transcription. Despite their lack of promoter regulation, IL-1 alpha and IL-1 beta also stimulated PGE2 production by ROS 17/2.8, further confirming the ability of the host cell to respond to these mediators. In dose-response experiments, down-regulation by TNF-alpha was significant at concentrations as low as 0.14 pM (0.1 U/ml), whereas approximately 10(4)-fold higher concentration of IL-6 was required to exert a similar effect. TNF-alpha-mediated down-regulation was unaffected by indomethacin. These data demonstrate that of these cytokines, TNF-alpha alone potently down-regulates osteocalcin promoter function, whereas IL-1 acts post-transcriptionally, possibly by reducing mRNA stability. Heterogeneity therefore exists among the proinflammatory cytokines with respect to the level at which control of osteocalcin expression is exerted.
 ...
PMID:Proinflammatory cytokines tumor necrosis factor-alpha and IL-6, but not IL-1, down-regulate the osteocalcin gene promoter. 130 41

Recent evidence has implicated cytokines and growth factors in the initiation of parturition in women. In the present study, the amnion-derived cell line WISH was used to determine whether proinflammatory cytokines (interleukins 1 beta, 6, and 8, tumor necrosis factor-alpha, and granulocyte/macrophage colony stimulating factor) could amplify epidermal growth factor-induced prostaglandin E2 production. WISH cells were preincubated with cytokines (0.0001-10 ng/ml) for 60 min and then challenged with EGF (10 ng/ml) for 4 hrs after which PGE2 production was measured by radioimmunoassay. EGF, IL-1 beta and TNF-alpha alone caused a dose-dependent increase in PGE2 production, while IL-6, IL-8 and GM-CSF were ineffective over the dose range tested. When cells were preincubated with IL-1 beta or TNF-alpha, there was a dose-dependent potentiation of EGF-induced PGE2 production that was greater than the sum of EGF alone and IL-1 beta or TNF-alpha alone. In each case, the minimum dose of IL-1 beta or TNF-alpha which amplified EGF-induced PGE2 production was 0.1 ng/ml (p less than 0.05, Student's t-test). These data show that low concentrations of IL-1 beta or TNF-alpha may serve to amplify EGF-mediated PGE2 biosynthesis in amnion-derived cells and suggest that cytokines may modulate EGF function in responsive cells.
 ...
PMID:Proinflammatory cytokines interact synergistically with epidermal growth factor to stimulate PGE2 production in amnion-derived cells. 141 May 28

Neutrophil-activating protein-2 (NAP-2), an NH2-terminally processed form of the platelet-release product beta thromboglobulin (beta TG), was purified to homogeneity from stimulated human blood leukocytes. In the presence of a vasodilator substance (PGE2, CGRP) picomolar (pmol/l) amounts of NAP-2 induced neutrophil accumulation and plasma leakage on intradermal injection in rabbit skin, whereas the longer forms, beta TG itself and connective tissue-activating peptide III (CTAP-III), had no such effect. NAP-2-induced increased in microvascular permeability was neutrophil dependent and fast in onset, with a half-life of 65 to 75 minutes, comparable to that previously reported for the structural-related neutrophil-activating protein-1/interleukin-8 (NAP-1/IL-8). However NAP-2 showed a lower potency in that more protein was needed to provoke skin reactivity. Nevertheless the finding that a platelet release product can elicit neutrophil-mediated inflammation further narrows the gap between thrombotic events and inflammatory disorders.
 ...
PMID:Increased microvascular permeability in vivo in response to intradermal injection of neutrophil-activating protein (NAP-2) in rabbit skin. 182 7

An in vivo experimental peritonitis model was investigated in the rabbit using zymosan as the inflammatory stimulus. After an i.p. injection of zymosan, exudate was removed at intervals and tested in the back skin of assay rabbits. Assay rabbits received i.v. injections of 125I-albumin and 111In-neutrophils, and the local accumulation of each label was measured in response to intradermal injections of exudate samples mixed with a potentiating dose of PGE2. When peritoneal exudate samples were tested in the presence of a specific anti-C5a antibody, virtually all the edema-inducing and neutrophil chemoattractant activity was abolished in samples taken up to 2 h after the zymosan injection. Later samples, however, contained increasing levels of a non-C5a component. In C5a-depleted 6-h exudate two peaks of inflammatory activity were separated using cation exchange HPLC. Evidence is presented that C5a itself is unable to stimulate the production of these activities. Both peaks of activity appear related to IL-8/NAP-1 as they inhibited the binding of 125I-IL-8/NAP-1 to human neutrophils.
 ...
PMID:The sequential generation of neutrophil chemoattractant proteins in acute inflammation in the rabbit in vivo. Relationship between C5a and proteins with the characteristics of IL-8/neutrophil-activating protein 1. 189 60

Glucocorticoids inhibit various components of the acute phase response, particularly the increase in body temperature (fever) induced by a variety of stimuli. In the present study these observations have been extended, and we have determined the effect of glucocorticoid treatment or surgical adrenalectomy on the cytokine and prostaglandin (PG) concentrations in plasma and cerebrospinal fluid (CSF) during the febrile response to endotoxin. Dexamethasone treatment, either before or after endotoxin injection, markedly inhibited fever and the increased plasma interleukin (IL)-6 and CSF IL-6, PGE2, and PGF2 alpha concentrations. Adrenalectomized (ADX) rats showed higher fevers and plasma and CSF IL-6, PGE2, and PGF2 alpha, concentrations compared with sham-operated animals and exhibited a lower plasma-to-CSF IL-6 ratio than sham-operated animals. Dexamethasone pretreatment also inhibited fever induced by centrally injected TNF-alpha, IL-1 beta, or IL-6. Pyrogenic response to IL-8 was not modified by indomethacin but was markedly inhibited by prior treatment with dexamethasone. These results support the hypothesis that endogenous glucocorticoids function as part of an inhibitory feedback system involved in the modulation of fever and that multiple mechanisms may be involved in their antipyretic effect.
 ...
PMID:Multiple mechanisms mediate antipyretic action of glucocorticoids. 757 52

Pneumocystis carinii pneumonia (PCP) may cause severe respiratory distress. This is believed to be partly caused by the accumulation of neutrophils in the lung. Interleukin-8 (IL-8) and leukotriene B4 (LTB4) are potent neutrophil chemo-attractants and activators. Eicosanoids [i.e. prostaglandins (PG) and leukotrienes (LT)] are pro-inflammatory mediators released from arachidonic acid by action of phospholipase A2 (PLA2) and have been implicated in the host response to micro-organisms. Bronchoalveolar lavage (BAL) was performed on patients with PCP as part of a randomized study of adjuvant corticosteroids vs. placebo, in addition to standard antimicrobial therapy. Re-bronchoscopy was offered at day 10. BAL fluid was available for 26 patients who had follow-up bronchoscopy performed. At diagnosis, IL-8 levels were elevated in patients with PCP, compared to healthy controls, and correlated with relative BAL neutrophilia and P(A-a)O2. LTB4 was also elevated in PCP, but failed to correlate with either BAL neutrophilia or P(A-a)O2. PLA2 activity in patients correlated with IL-8 levels and BAL neutrophilia, but not with P(A-a)O2. A trend towards a decrease in IL-8 levels in BAL fluid was detected in the corticosteroid-treated patients from days 0-10, whereas no change was detected in the placebo group. No change in levels of LTB4, LTC4, PGE2, PGF2a and PLA2 were detected cover time in either treatment group. This study establishes a correlation between IL-8, BAL neutrophilia and P(A-a)O2, and suggests a role of IL-8 as a mediator in the pathogenesis of PCP, whereas the role of eicosanoids seems less clear.
 ...
PMID:Interleukin-8 and eicosanoid production in the lung during moderate to severe Pneumocystis carinii pneumonia in AIDS: a role of interleukin-8 in the pathogenesis of P. carinii pneumonia. 759 68

The effect of (R)-1-(5-hydroxyhexyl)-3,7-dimethylxanthine (CT-1501R; the nonproprietary name for CT-1501R approved by the United States Name Council is lisofylline), an inhibitor of second messenger signaling through phosphatidic acid, on release of endogenous mediators important in the systemic inflammatory response syndrome (SIRS) was studied using the human whole blood ex vivo assay system. Human blood was stimulated with various endotoxin preparations, zymosan, or protein A, and the levels of secreted monokines were measured by enzyme-linked immunosorbent assay. CT-1501R inhibited tumor necrosis factor alpha (TNF-alpha), interleukin 1 beta (IL-1 beta), and IL-6 release in a dose-dependent manner and was active with all stimuli tested including Salmonella and Escherichia coli-derived endotoxin, endotoxin from both rough and smooth E. coli strains, as well as zymosan and protein A. CT-1501R inhibited monokine release by approximately 50% at 200 microM and 30% at 50 microM and was independent of the relative potency of stimulus. CT-1501R also inhibited IL-1 alpha or IL-1 beta induction of either TNF-alpha or IL-1 beta and inhibited the synergistic effects of stimulation with both human IL-1 beta and murine TNF-alpha on release of human TNF-alpha. Inhibition of monokine release following stimulation with monokine(s) was, in general, greater than that achieved with lipopolysaccharide (LPS) stimulation. Northern blot analysis showed decreased mRNA accumulation of TNF-alpha and IL-1 beta in CT-1501R-treated samples following LPS stimulation suggesting that CT-1501R acts at least in part, at the pretranslational level. In contrast, CT-1501R does not inhibit LPS-stimulated IL-8 or IL-1 receptor antagonist (IL-1ra) release in human whole blood or IL-1 alpha-induced release of PGE2 in human foreskin fibroblast cells. These data suggest that CT-1501R may be of use for clinical intervention in SIRS.
 ...
PMID:CT-1501R selectively inhibits induced inflammatory monokines in human whole blood ex vivo. 773 59

Prostaglandin E2 (PGE2) appears to regulate macrophage cytokine production through the stimulatory GTP-binding protein (Gs protein)-mediated cyclic AMP (cAMP)-dependent transmembrane signal transduction pathway. In this study, we used PGE2, cholera toxin (CT; a direct G alpha s protein stimulator) and 8-bromo-cAMP (a membrane permeable cAMP analogue) to stimulate this pathway, and investigated their influence on cytokine gene expression in lipopolysaccharide (LPS)-activated human macrophages. The mRNA expression for interleukin-1 alpha (IL-1 alpha), IL-1 beta, tumour necrosis factor-alpha (TNF-alpha), IL-6 and IL-8 were determined employing reverse transcription polymerase chain reaction (RT-PCR) using specific primers. We demonstrated that PGE2, CT and 8-bromo-cAMP inhibited the LPS-induced gene activation of TNF-alpha and IL-1 alpha, and had no effect on the gene activation of IL-1 beta and IL-8. Further, our data indicate that PGE2 suppressed the gene activation of IL-6 following LPS stimulation, but neither CT nor 8-bromo-cAMP had an effect. These data suggest that PGE2 alters LPS-stimulated gene activation of only some of the early macrophage cytokines, and does so either by a Gs transmembrane cAMP-dependent or an independent system.
 ...
PMID:Effects of prostaglandin E2, cholera toxin and 8-bromo-cyclic AMP on lipopolysaccharide-induced gene expression of cytokines in human macrophages. 775 Oct 29

Two human skin recombinants, the epidermis reconstructed on the deepidermized dermis (RE-DED) or on fibroblast-populated collagen matrix (Living Skin Equivalent, LSE), were used to study the irritating effect of sodium lauryl sulfate (SLS). The extent of cytotoxicity induced after a 24-hour exposure period to increasing concentrations of SLS (0-5%) was evaluated on the basis of (1) morphological perturbations, (2) changes in the expression of differentiation-specific protein markers (keratin 1, 10, 6, 16, involucrin and transglutaminase), (3) cell membrane integrity (LDH leakage) and (4) release of proinflammatory mediators (PGE2, IL-1, IL-6 and IL-8). SLS induced significant changes in epidermal morphology and changes in the expression and localization of differentiation-specific protein markers when applied topically in concentrations higher than 1% on RE-DED and higher than 0.1% on LSE. The exposure of both human skin recombinants to SLS resulted in a dose-dependent release of LDH, PGE2 and IL-1 alpha and in an increase in keratinocyte intracellular IL-1 levels. Upon application of 5% SLS on RE-DED the total (intra- and extracellular) IL-1 levels remained high but due to cell damage the intracellular IL-1 level was markedly decreased and the extracellular IL-1 level increased. Similar observations have been made with LSE after application of 0.5% SLS. However, with LSE the extracellular IL-1 alpha levels were found to be about 100 times lower than those measured with RE-DED. Exposure of LSE to SLS induced a marked increase of IL-6 production in fibroblasts incorporated in the collagen matrix. Contrary to LSE, both intra- and extracellular levels of IL-6 were low in unexposed controls and were only marginally modulated by the exposure of the RE-DED to SLS. In addition, a dose-dependent increase in IL-8 release was observed upon application of SLS on RE-DED. The results of the present study indicate that concentrations of SLS required to induce epidermal irritancy in vitro approximate those inducing irritation in human skin in vivo. All parameters used in the present study for evaluation of toxicity can serve as useful endpoints for screening of contact skin irritancy in vitro. Compared to RE-DED, the LSE seems to be more susceptible to SLS. The differences in sensitivity between LSE and RE-DEd can be ascribed to reported differences in their stratum corneum barrier function.
 ...
PMID:Use of human skin recombinants as an in vitro model for testing the irritation potential of cutaneous irritants. 778 25

Major trauma and consecutively associated infectious complications have a major impact on the mechanisms of the specific immune response and the nonspecific inflammatory reaction. The trauma-induced host defense abnormalities become strikingly evident with the analysis of cytokine synthesis patterns. The dissociation of cell-mediated immune responses following trauma is based upon an overrepresentation of suppressor-active monocytes and inadequate T-cell help in parallel. Corresponding dysregulation of cytokine production appears within many facets. Complement, endotoxin and antigen antibody complexes cause a massive activation of monocytes with an abnormal release of essential mediators, like PGE2, IL-1, IL-6, IL-8, TGF-beta and TNF-alpha. The regulation of cytokine synthesis under stressful conditions is differentially regulated for the individual mediators, either on a transcriptional or a posttranscriptional level. In our opinion, the endogenous provisions of the organism for survival following major injury are inadequate and from this hypothesis we derive the necessity for a substantial exogenous therapeutic intervention. The primary target of modern immunotherapy must be to inhibit the conversion of a systemic inflammatory reaction in immunocompromised patients towards a status of bacterial sepsis. Different approaches appear to be feasible to avoid the development of late multiorgan failure. These interventions have to be utilized preventively in a controlled manner as early as possible after trauma has occurred, and they must effectively protect different cell systems (lymphocytes, monocytes, PMNs and endothelial cells).
 ...
PMID:[Immune mechanisms of post-traumatic hyperinflammation and sepsis]. 782 50


1 2 3 4 5 6 7 8 9 10 Next >>