Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P43026 (lipopolysaccharide)
 62,215 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The interleukin-1 (IL-1) receptor antagonist (IL-1ra) is an endogenous antagonist that blocks the effects of the proinflammatory cytokines IL-1alpha and IL-1beta by occupying the type I IL-1 receptor. Here we describe transgenic mice with astrocyte-directed overexpression of the human secreted IL-1ra (hsIL-1ra) under the control of the murine glial fibrillary acidic protein (GFAP) promoter. Two GFAP-hsIL-1ra strains have been generated and characterized further: GILRA2 and GILRA4. These strains show a brain-specific expression of the hsIL-1ra at the mRNA and protein levels. The hsIL-1ra protein was approximated to approximately 50 ng/brain in cytosolic fractions of whole brain homogenates, with no differences between male and female mice or between the two strains. Furthermore, the protein is secreted, inasmuch as the concentration of hsIL-1ra in the cerebrospinal fluid was 13 (GILRA2) to 28 (GILRA4) times higher in the transgenic mice than in the control animals. To characterize the transgenic phenotype, GILRA mice and nontransgenic controls were injected with recombinant human IL-1beta (central injection) or lipopolysaccharide (LPS, peripheral injection). The febrile response elicited by IL-1beta (50 ng/mouse icv) was abolished in hsIL-1ra-overexpressing animals, suggesting that the central IL-1 receptors were occupied by antagonist. The peripheral LPS injection (25 micrograms/kg ip) triggered a fever in overexpressing and control animals. Moreover, no differences were found in LPS-induced (100 and 1,000 micrograms/kg ip; 1 and 6 h after injection) IL-1beta and IL-6 serum levels between GILRA and wild-type mice. On the basis of these results, we suggest that binding of central IL-1 to central IL-1 receptors is not important in LPS-induced fever or LPS-induced IL-1beta and IL-6 plasma levels.
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PMID:Acute-phase responses in transgenic mice with CNS overexpression of IL-1 receptor antagonist. 1007 Jan 23

IL-10 is a well-known immunosuppressive and/or anti-inflammatory cytokine. However, we report in vitro experimental studies in which IL-10 primed leukocytes and led to an enhanced production of tumor necrosis factor (TNF) upon further stimulation by lipopolysaccharide (LPS). Monocytes and peripheral blood mononuclear cells (PBMC) prepared from whole blood maintained for 20 h at 37 degrees C in the presence of recombinant human IL-10 had an enhanced capacity to produce TNF in response to LPS. In addition to TNF, LPS-induced IL-6 and spontaneous IL-1ra production were also enhanced. When isolated PBMC were first cultured for 20 h in the presence of IL-10 on Teflon to prevent adherence, washed to remove IL-10 and then further cultured in plastic dishes for an additional 20 h in the presence of LPS or IL-1beta, an enhanced release of TNF was observed. This was not the case when PBMC were pre-cultured in plastic multidishes in the presence of IL-10. TNF mRNA expression induced by LPS was decreased when the pre-treatment of PBMC with IL-10 was performed on plastic, whereas this was not the case when cells were pre-cultured with IL-10 on Teflon. Furthermore, NFkappaB translocation following LPS activation was higher after IL-10 pre-treatment on Teflon than on plastic. Interestingly, an enhanced frequency of CD16 and CD68(+) cells among the CD14(+) cells was observed in the presence of IL-10, independently of the pre-culture conditions of the PBMC. Altogether, these results indicate that the IL-10-induced up-regulation of cytokine production depends on the prevention of monocyte adherence by red cells in the whole blood assays or by cultures of PBMC on Teflon. In contrast, the adherence parameter has no effect on the IL-10-induced modulation of some monocyte surface markers.
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PMID:Paradoxical priming effects of IL-10 on cytokine production. 1033 Feb 74

Interleukin-1 is a potent mediator of inflammation, involved in regulating a wide variety of physiological and cellular events. We have identified and characterized a novel member of the human interleukin-1 gene family (IL1HY1). The encoded protein demonstrates significant amino acid homology to the receptor antagonist (IL-1ra) at 52%. The gene was mapped to the long arm of chromosome 2, in close proximity to the IL-1 locus. IL1HY1 message is tightly regulated being most predominantly expressed in the skin, but also detected in the spleen, brain leukocyte, and macrophage cell types. Furthermore, the message can be induced in THP-1 cells by phorbol ester (PMA) and lipopolysaccharide (LPS) treatment.
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PMID:IL1HY1: A novel interleukin-1 receptor antagonist gene. 1051 43

Gallbladder inflammation is an early feature of gallstone formation in animal models. The inflammatory response is associated with increases in myeloperoxidase and interleukin (IL)-1 activities in the gallbladder wall. The present studies were designed to determine whether inflammatory cytokines directly affect gallbladder epithelial cell absorptive function. Studies were performed using cultured human gallbladder epithelial cells derived from a well-differentiated gallbladder carcinoma. Confluent monolayers were exposed to interleukin-1 (IL-1alpha), IL-1alpha plus its specific receptor inhibitor IL-1ra, tumor necrosis factor (TNF-alpha), lipopolysaccharide, or prostaglandin E2. Unidirectional sodium and chloride fluxes were measured and used to calculate net ion fluxes. Compared to control monolayers, lipopolysaccharide, prostaglandin E2, IL-1alpha, and TNF-alpha decreased mucosal-to-serosal and net sodium and chloride fluxes and increased serosal-to-mucosal movement of sodium and unmeasured ions. The effects of IL-1alpha were completely inhibited by its specific receptor antagonist IL-1ra. Similar to the proinflammatory agents lipopolysaccharide and prostaglandin E2, the inflammatory cytokines IL-1alpha and TNF-alpha directly affected gallbladder epithelial cell absorptive function. Because normal gallbladder absorptive function is protective against gallstone formation, alterations in absorptive function due to inflammation in the gallbladder wall may play a role in gallstone pathogenesis.
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PMID:Inflammatory cytokines alter human gallbladder epithelial cell absorption/secretion. 1067 42

We examined leukocyte counts and ex vivo cytokine response of whole blood to lipopolysaccharide (LPS) or lipoteichoic acid (LTA) in patients under low-dose molgramostim therapy. Patients were injected subcutaneously daily for ten days with 1 microg/kg (n=9) or 2 microg/kg (n=14) molgramostim. Leukocytosis was observed in all patients, but only the eosinophil fraction was significantly increased in relation to other leukocyte populations. Ex vivo IFN-gamma release was decreased and IL-10 and IL-1ra secretion were increased in response to LPS or LTA. Thus, in non-neutropenic patients, leukocytosis can already be initiated by low doses of molgramostim. The ex vivo cytokine data suggest that these doses prime blood towards a systemic anti-inflammatory response.
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PMID:Blood cytokine response of low-dose molgramostim (rhGM-CSF)-treated patients. 1102 76

The potential anti-inflammatory role of alpha-melanocyte-stimulating hormone (alpha-MSH)-related tripeptide, lysine(11)-D-proline-valine(13) (KDPV), an analogue of interleukin (IL)-1beta(193-195) and an antagonist of IL-1beta/prostaglandin E(2), is not well characterized in the alveolar epithelium. In a model of foetal alveolar type II epithelial cells in vitro, we showed that lipopolysaccharide endotoxin (LPS) differentially, but selectively, induced the nuclear subunit composition of nuclear factor kappaB(1) (NF-kappaB(1)) (p50), RelA (p65) and c-Rel (p75), in parallel to up-regulating the DNA-binding activity (supershift indicating the presence of the p50-p65 complex). LPS accelerated the degradation of inhibitory kappaB-alpha (IkappaB-alpha), accompanied by enhancing its phosphorylation in the cytosolic compartment but not in the nucleus. KDPV suppressed, in a dose-dependent manner, the nuclear localization of p50, p65 and p75, an effect that led to the subsequent inhibition of NF-kappaB activation. Interleukin-1 receptor antagonist (IL-1ra) decreased the nuclear abundance of p50, p65 and p75, and subsequently depressed the DNA-binding activity induced by LPS. Analysis of the mechanism involved in the KDPV- and IL-1ra-mediated inhibition of NF-kappaB nuclear localization revealed a reversal in IkappaB-alpha phosphorylation and degradation, followed by cytosolic accumulation. LPS induced endogenous IL-1beta biosynthesis in a time-dependent manner; the administration of exogenous recombinant human interleukin 1 (rhIL-1) resulted in a dose-dependent activation of NF-kappaB. KDPV and IL-1ra abrogated the effect of rhIL-1. Pretreatment with the non-steroidal anti-inflammatory drug (NSAID) indomethacin, an inhibitor of cyclo-oxygenase, blocked the LPS-induced activation of NF-kappaB. These results indicate the involvement of prostanoid-dependent (NSAID-sensitive) and IL-1-dependent (IL-1ra-sensitive) mechanisms mediating LPS-induced NF-kappaB translocation and activation, a pathway that is regulated, in part, by a negative feedback mechanism transduced through IkappaB-alpha, the major cytosolic inhibitor of NF-kappaB.
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PMID:Alpha-melanocyte-related tripeptide, Lys-d-Pro-Val, ameliorates endotoxin-induced nuclear factor kappaB translocation and activation: evidence for involvement of an interleukin-1beta193-195 receptor antagonism in the alveolar epithelium. 1125 45

The endogenous interleukin-1 receptor antagonist is the natural inhibitor of the biological effects of interleukin-1 during inflammation. Interleukin-1 receptor antagonist refers to three isoforms: one secreted and two intracellular forms (types I and II). The objective of the present study was to investigate the expression of interleukin-1 receptor antagonist isoforms in the rat brain in vivo in response to an i.p. injection of lipopolysaccharide. The interleukin-1 receptor antagonist was studied at the messenger and protein levels by reverse transcription-polymerase chain reaction and western blot analysis, respectively. Interleukin-1 receptor antagonist messenger RNA was constitutively expressed in the brain and its expression increased in response to lipopolysaccharide. The three interleukin-1 receptor antagonist protein isoforms were up-regulated after lipopolysaccharide treatment in a time-dependent manner. Their relative expression differed according to the isoform and brain region studied. Double immunofluorescence staining revealed interleukin-1 receptor antagonist positive neurons and microglia in hippocampus 24h after lipopolysaccharide stimulation. These results demonstrate for the first time that brain cells are able to produce interleukin-1 receptor antagonist isoforms in response to a peripheral immune challenge with a predominance of the secreted over intracellular forms.
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PMID:Characterization of interleukin-1 receptor antagonist isoform expression in the brain of lipopolysaccharide-treated rats. 1131 97

Toll-like receptors (TLRs) are involved in human monocyte activation by lipopolysaccharide (LPS) and Staphylococcus aureus Cowan (SAC), suggesting that gram-positive and gram-negative bacteria may trigger similar intracellular events. Treatment with specific kinase inhibitors prior to cell stimulation dramatically decreased LPS-induced cytokine production. Blocking of the p38 pathway prior to LPS stimulation decreased interleukin-1alpha (IL-1alpha), IL-1ra, and tumor necrosis factor alpha (TNF-alpha) production, whereas blocking of the ERK1/2 pathways inhibited IL-1alpha, IL-1beta, and IL-1ra but not TNF-alpha production. When cells were stimulated by SAC, inhibition of the p38 pathway did not affect cytokine production, whereas only IL-1alpha production was decreased in the presence of ERK kinase inhibitor. We also demonstrated that although LPS and SAC have been shown to bind to CD14 before transmitting signals to TLR4 and TLR2, respectively, internalization of CD14 occurred only in monocytes triggered by LPS. Pretreatment of the cells with SB203580, U0126, or a mixture of both inhibitors did not affect internalization of CD14. Altogether, these results suggest that TLR2 signaling does not involve p38 mitogen-activated protein kinase signaling pathways, indicating that divergent pathways are triggered by gram-positive and gram-negative bacteria, thereby inducing cytokine production.
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PMID:Gram-positive and gram-negative bacteria do not trigger monocytic cytokine production through similar intracellular pathways. 1140 3

CD14 is a pattern recognition receptor for the bacterial cell wall components from Gram-positive and Gram-negative bacteria as well as mycobacteria. Binding of lipopolysaccharide (LPS) or other cell wall constituents to CD14 initiates signal transduction through the Toll-like receptors resulting in the release of pro-inflammatory cytokines and the initiation of the systemic inflammatory response. In rabbits and non-human primates, CD14 specific antibodies were shown to attenuate responses to LPS or Escherichia coli challenge including pro-inflammatory cytokine release, acute lung injury, hypotension and changes in lung, liver, spleen and adrenal gland morphology. In healthy human subjects, single doses of a chimeric CD14 antibody (IC14) have been shown to be well tolerated and result in a dose-related degree of saturation of CD14 receptors on monocytes and granulocytes. Pretreatment of healthy subjects with IC14 2 h prior to LPS resulted in an attenuation of the LPS-induced fever, clinical symptoms, and leukocyte activation and degranulation. IC14 inhibited the release of TNF-alpha, IL-6, and IL-10 and delayed the release of sTNFR(I) and IL-1ra. Further studies are in progress to characterize the safety and clinical pharmacology of IC14 in patients with severe sepsis.
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PMID:IC14, a CD14 specific monoclonal antibody, is a potential treatment for patients with severe sepsis. 1171 88

Acute stressor exposure can facilitate innate immunity and suppress acquired immunity. The present study further characterized the potentiating effect of stress on innate immunity, interleukin-1beta (IL-1beta), and demonstrated that stress-induced potentiation of innate immunity may contribute to the stress-induced suppression of acquired immunity. The long-term effect of stress on IL-1beta was measured by using an ex vivo approach. Sprague-Dawley rats were challenged with lipopolysaccharide (LPS) in vivo, and the IL-1beta response was measured in vitro. Splenocytes, mesenteric lymphocytes, and peritoneal cavity cells had a dose- and time-dependent ex vivo IL-1beta response to LPS. Rats that were exposed to inescapable shock (IS, 100 1.6 mA, 5-s tail shocks, 60-s intertrial interval) and challenged with a submaximal dose of LPS 4 days later had elevated IL-1beta measured ex vivo. To test whether the acute stress-induced elevation in IL-1beta contributes to the long-term suppression in acquired immunity, IL-1beta receptors were blocked for 24 h after stress. Serum anti-keyhole limpet hemocyanin (KLH) immunoglobulin (Ig) was measured. In addition, the acute elevation (2 h post-IS) of splenic IL-1beta in the absence of antigen was verified. Interleukin-1 receptor antagonist prevented IS-induced suppression in anti-KLH Ig. These data support the hypothesis that stress-induced increases in innate immunity (i.e., IL-1beta) may contribute to stress-induced suppression in acquired immunity (i.e., anti-KLH Ig).
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PMID:Elevated IL-1beta contributes to antibody suppression produced by stress. 1207 Feb 7


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