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Query: UNIPROT:P10145 (
IL-8
)
23,849
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The neuropeptide alpha-melanocyte stimulating hormone [alpha-MSH(1-13)] occurs in the pituitary, brain, skin and other tissues and receptors for this molecule are likewise widespread. In previous research, this tridecapeptide, which shares its amino acid sequence with ACTH(1-13), was shown to have both potent antipyretic activity and a role in the endogenous control of the febrile response. alpha-MSH(1-13) and its COOH-terminal tripeptide were subsequently found to inhibit inflammation induced by general stimuli such as topical application of an irritant. The aim in the present experiments was to determine if these peptides can inhibit acute inflammatory responses induced in mice by injection of individual cytokines, endogenous pyrogen (EP), a natural cytokine mixture, and other mediators of inflammation. Inflammation induced in the mouse ear by rIL-1 beta, rIL-6 or rTNF-alpha was inhibited by alpha-MSH and a D-valine-substituted analog of alpha-MSH(11-13) whereas substantial doses of alpha-MSH(1-13) did not alter inflammation induced by LTB4,
PAF
and
IL-8
. Both peptides inhibited edema caused in the mouse paw by local injection of EP. The results indicate that alpha-MSH molecules antagonize the actions of certain cytokine mediators of inflammation, consistent with previous observations of anti-cytokine activity of these peptides. Failure to inhibit edema caused by LTB4,
PAF
and
IL-8
suggests that, in inflammation induced by general stimuli, such as EP, the peptides act prior to the release of these mediators of the inflammatory response. Because of the anticytokine/anti-inflammatory actions of the alpha-MSH molecules they may be useful in understanding the cytokine network and for treatment of inflammatory diseases.
...
PMID:Alpha-MSH peptides inhibit acute inflammation induced in mice by rIL-1 beta, rIL-6, rTNF-alpha and endogenous pyrogen but not that caused by LTB4, PAF and rIL-8. 132 96
Neutrophils from patients suffering from severe congenital neutropenia (SCN), who were receiving recombinant human granulocyte colony-stimulating factor (rhG-CSF), were investigated in order to analyze the previously described decrease in chemotaxis. This study demonstrated the decreased chemotaxis to five well-known chemoattractants, FMLP, C5a,
IL-8
, LTB4 and
PAF
. To further investigate this impairment of patients' neutrophils, receptors and receptor turnover for chemoattractants were examined using flow cytometry. We found 1) increased FMLP receptor and decreased C5a receptor expression, 2) a normal expression of intracellular FMLP receptors after incubation with PMA, 3) increased loss and decreased re-expression of FMLP receptors after incubation with this peptide, 4) normal expression of adhesion glycoproteins CR3 (CD11b/CD18) and LFA1 (CD11a/CD18), 5) further signs of in vivo preactivation: high expression of Fc gamma-RI (CD64) and Fc gamma-RII (CD32), decreased expression of Fc gamma-RIII (CD16), increased expression of CD14, and low expression of HLA-DR. These data demonstrate that the decrease of chemotaxis of neutrophils from SCN patients is not due: a) to a decrease in the number of intra- or extracellular FMLP receptors; b) to a decrease of adhesion molecules. However, the decreased chemotaxis could result from an altered FMLP receptor turnover. The relevance of the altered Fc gamma-receptor pattern for the in vivo occurrence of side-effects, e.g. the necrotic vasculitis, of G-CSF treatment is discussed.
...
PMID:Altered function and surface marker expression of neutrophils induced by rhG-CSF treatment in severe congenital neutropenia. 137 Apr 19
We examined the production of
PAF
and LTB4 by PMN in response to NAP1/
IL-8
alone, or after preincubation with GM-CSF, which has been shown to enhance PMN responsiveness and to prime PMN for production of those bioactive lipids.
NAP-1
/
IL-8
does not induce the synthesis of
PAF
and LTB4 from endogenous phospholipid precursors, even after preincubation with GM-CSF. In addition and again in contrast to fMLP and C5a,
NAP-1
/
IL-8
fails to induce an enhanced oxidative burst in GM-CSF primed PMN. Exogenously added
PAF
or LTB4 can mimic the priming effect of GM-CSF for an enhanced oxidative burst in response to all examined chemotactic peptides including NAP1/
IL-8
. Our data reveal a possible autocrine role of
PAF
and LTB4 in the enhanced responsiveness of GM-CSF primed PMN towards fMLP or C5a, but not
NAP-1
/
IL-8
.
...
PMID:Receptor-operated activation of polymorphonuclear leukocytes: different effects of NAP-1/IL-8 and fMet-Leu-Phe or C5a. 164 49
LPS and mitogen-stimulated mononuclear cells secrete a cytokine, which is able to activate the PMNL-arachidonate-5-lipoxygenase. This cytokine has been proven to be identical with the recently characterized novel neutrophil-activating peptide NAP/
IL-8
. NAP/
IL-8
is able to activate human PMNL for release of LTB4, omega-oxidized LTB4, and 5-HETE in the presence of exogenous AA. Half-maximal concentration of NAP/
IL-8
for release of LTB4 has been found to be near 4 x 10(-8) mol/liter. Time course studies revealed rapid activation of PMNL, with maximal release of LTB4 within the first 10 min with a decline up to 40 min. High amounts of omega-oxidized LTB4 were detected up to that time. Significant amounts of AA-5-LO-products can be detected only when PMNL were stimulated with NAP/
IL-8
in the presence of exogenous AA. The concentration of AA necessary for half-maximal LTB4 release has been found to be 3 x 10(-6) mol/liter. In the presence of 8 x 10(-9) mol/liter [3H]AA, NAP/
IL-8
(10(-9) to 10(-7) mol/liter) did not induce the production of LTB4, omega-oxidized LTB4, or 5-HETE. In addition, PMNL prelabeled with [3H]AA did not release either [3H]AA or 5-lipoxygenase metabolites when stimulated with NAP/
IL-8
(10(-9) to 10(-7) mol/liter), indicating that NAP/
IL-8
apparently does not activate cellular phospholipases/diacylglycerol-lipases. Apart from FMLP, C5a, and
PAF
NAP/
IL-8
is the fourth clearly characterized neutrophil chemotaxin able to activate the PMNL-5-lipoxygenase. The detection of large amounts of NAP/
IL-8
, arachidonic acid, as well as LTB4-like material, in lesional material of patients with psoriasis points towards a possibly important role of NAP/
IL-8
in amplifying inflammatory processes by induction of LTB4-production.
...
PMID:The monocyte-derived neutrophil activating peptide (NAP/interleukin 8) stimulates human neutrophil arachidonate-5-lipoxygenase, but not the release of cellular arachidonate. 254 66
The aims of the study were to determine whether the platelet-activating factor antagonist Lexipafant could alter the clinical course and suppress the inflammatory response of human acute pancreatitis. In a double-blind, placebo-controlled study 83 patients were randomized to receive Lexipafant 60 mg intravenously for 3 days, or placebo. Clinical progression was assessed by daily Acute Physiology And Chronic Health Evaluation (APACHE) II score and organ failure score (OFS). The magnitude of the inflammatory response on days 1-5 was assessed by serial measurement of interleukin (IL) 8, IL-6, E-selectin, polymorphonuclear elastase-alpha1-antitrypsin (PMNE-alpha 1-AT), and C-reactive protein (CRP). At entry, patients receiving Lexipafant (n = 42) or placebo (n = 41) were matched for age and sex, aetiology, APACHE II score and OFS. The disease was classified as severe in 29 patients (APACHE II score eight or more). There was a significant reduction in the incidence of organ failure (P = 0.041) and in total OFS (P = 0.048) at the end of medication (72 h). During this time seven of 12 patients with severe acute pancreatitis who had Lexipafant recovered from an organ failure; only two of 11 with severe acute pancreatitis who had placebo recovered from an organ failure and two others developed new organ failure. Lexipafant treatment significantly reduced serum
IL-8
(P = 0.038), and IL-6 declined on day 1. Plasma PMNE-alpha 1-AT complexes peaked on day 1; the gradual fall to baseline over 5 days observed in controls did not occur in patients given Lexipafant. No effect was observed on serum CRP. This study provides a rationale for further clinical trials with the potent
PAF
antagonist Lexipafant in human acute pancreatitis.
...
PMID:Randomized, double-blind phase II trial of Lexipafant, a platelet-activating factor antagonist, in human acute pancreatitis. 748 82
It is generally accepted that the beta 2-integrin is restricted to mononuclear leukocytes. The objective of this study was to determine whether neutrophils can also express beta 1-integrin (specifically alpha 4 beta 1) and whether this can support neutrophil adhesion to endothelial cells and to extracellular matrix. We stimulated neutrophils with dihydrocytochalasin B (DHCB) and various chemotactic stimuli and observed that chemotactic stimuli induced neutrophil adhesion via beta 2-integrin (CD18), whereas DHCB and either fMLP,
PAF
, or
IL-8
induced adhesion to endothelium or protein-coated plastic that was not inhibitable by anti-CD18 antibody. beta 2-integrin-deficient cells, which did not respond to chemotactic stimuli alone, also adhered avidly in the presence of chemotactic stimuli and DHCB. The induced neutrophil adhesion was inhibited by antibody to beta 1- or alpha 4-integrin chains, but only if an anti-beta 2-integrin antibody was also present. Flow cytometry revealed increased expression of both beta 1 and alpha 4 in the presence of fMLP plus DHCB. Transendothelial migration of neutrophils induced by chemotactic stimuli alone also increased expression of beta 1 and alpha 4. Transmigration across deendothelialized membranes induced a similar beta 1 expression on neutrophils suggesting that events other than an endothelial signal elicited beta 1-integrin expression. Transmigration-induced beta 1-dependent expression translated into only modest adhesion to protein-coated plastic. These data suggest that both a pharmacological (DHCB) and a physiological (transmigration) stimulus can invoke expression of alpha 4 and beta 1 on human neutrophils to mediate adhesion.
...
PMID:A novel beta 1-dependent adhesion pathway on neutrophils: a mechanism invoked by dihydrocytochalasin B or endothelial transmigration. 754 10
CP-105696, (+)-1-(3S,4R)-[3-(4-phenyl-benzyl)-4-hydroxy-chroman-7-yl] cyclopentane carboxylic acid, is a structurally novel, selective and potent leukotriene B4 (LTB4) receptor antagonist. In vitro, CP-105696 inhibited [3H]LTB4 (0.3 nM) binding to high-affinity LTB4 receptors on human neutrophils with an IC50 value of 8.42 +/- 0.26 nM. Scatchard analyses of [3H]LTB4 binding to these high-affinity receptors indicated that CP-105696 acted as a noncompetitive antagonist. CP-105696 inhibited human neutrophil chemotaxis mediated by LTB4 (5 nM) in a noncompetitive manner with an IC50 value of 5.0 +/- 2.0 nM. Scatchard analyses of [3H]LTB4 binding to low-affinity receptors on neutrophils indicated that CP-105696 acted as a competitive antagonist at this receptor, and inhibition of LTB4-mediated CD11b upregulation on human neutrophils was competitively inhibited by CP-105696 (pA2 = 8.03 +/- 0.19). CP-105696 at 10 microM did not inhibit either human neutrophil chemotaxis or CD11b upregulation mediated through alternate (i.e., C5a,
IL-8
,
PAF
) G-protein coupled chemotactic factor receptors. In isolated human monocytes, LTB4 (5 nM)-mediated Ca++ mobilization was inhibited by CP-105696 with an IC50 value of 940 +/- 70 nM. In vivo, after oral administration, CP-105696 blocked neutrophil and eosinophil infiltration in cavine dermis mediated by either LTB4 or arachidonic acid with ED50 values of 0.3 +/- 0.1 mg/kg. 12(R)-Hydroxyeicosatetraenoic acid-mediated neutrophil infiltration was blocked by 76.4 +/- 14.8% at 3 mg/kg.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:The in vitro and in vivo pharmacologic activity of the potent and selective leukotriene B4 receptor antagonist CP-105696. 771 64
The aim of the present study was to investigate directly and characterize the ability of IL-1 beta in inducing eosinophil accumulation in vivo. For this purpose, we studied the recruitment of 111In-labeled eosinophils in rat skin in response to intradermally injected rat rIL-1 beta. Rat rIL-1 induced a dose-dependent accumulation of 111In-labeled eosinophils, with the maximal response being detected at 5 x 10(-13) mol/site. This response was slow in onset, progressively increasing over the 4-h period investigated. Rat rIL-1 also induced a small level of edema, as measured by the local accumulation of i.v. 125I-labeled albumin, which developed with a time course similar to that of 111In-labeled eosinophil accumulation. Co-administration of the cytokine with the IL-1R antagonist, IL-1ra, or actinomycin D, significantly inhibited the 111In-labeled eosinophil accumulation, and reduced the edema formation, induced by rat rIL-1. In addition, the 111In-labeled eosinophil accumulation was significantly suppressed in animals treated with the
PAF
antagonist UK-74,505 or an anti-human
IL-8
mAb DM/C7. These observations demonstrate for the first time that IL-1 beta is a potent inducer of eosinophil accumulation in vivo. Moreover, the results reveal that this activity of IL-1 beta is receptor mediated and dependent on the induction of proteins that may be involved in the local generation of secondary inflammatory mediators including
PAF
and an
IL-8
-like molecule. These findings are consistent with the view that endogenously generated IL-1 may play an important role in the recruitment of eosinophils at sites of allergic inflammation.
...
PMID:IL-1 is a potent inducer of eosinophil accumulation in rat skin. Inhibition of response by a platelet-activating factor antagonist and an anti-human IL-8 antibody. 782 3
It has been shown that histamine induces early changes on endothelial cells (EC), such as a transient expression of P-selectin and secretion and/or surface expression of early mediators (eg, prostacyclin [PG1(2)], platelet-activating factor [
PAF
], and leukotriene B4 [LTB4]). However, delayed effects of histamine on EC and particularly on cytokine production are undefined. In this study, the effect of histamine on interleukin (IL)-8 production by EC was evaluated using an enzyme-linked immunosorbent assay (ELISA) method and mRNA expression. The results showed that histamine increased the secretion and the mRNA expression of
IL-8
by EC. Histamine-induced
IL-8
production was (1) dose-dependent (at a dose > or = 10(-6) mol/L), (2) potentialized by costimulation with tumor necrosis factor (TNF)-alpha, (3) inhibited by H1 or H2 histamine receptor antagonists, and (4) significantly increased 4 hours after the initial stimulation. These data suggest that histamine may be involved in the control of the late inflammatory reaction associated to allergic disorders through
IL-8
secretion by EC.
...
PMID:Histamine induces interleukin-8 secretion by endothelial cells. 791 40
Platelet activating factor acetylhydrolase (PAF-AH) activity was measured in patients with sepsis, and its relationships with various cytokines and endotoxin were evaluated.
PAF
-AH activity was significantly higher (p = 0.0136) in 17 patients who died than 13 patients who survived.
PAF
-AH activity showed significant correlations with the plasma endotoxin, TNF-alpha, and
IL-8
levels. These findings suggest that
PAF
-AH activity reflects the severity of the pathological condition.
...
PMID:Platelet-activating factor (PAF) acetylhydrolase activity, type II phospholipase A2, and cytokine levels in patients with sepsis. 800 78
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