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

In rats, fever can be induced by injection of bacterial lipopolysaccharide (LPS) into a subcutaneous air pouch. This febrile response is in part dependent on the local action of interleukin-1beta within the pouch. In the present study, we tried to find out if this model of fever induction can be applied in guinea pigs and if the local LPS-induced formation of tumor necrosis factor-alpha (TNF-alpha) participates in the development of the febrile response. A dose of 100 microg/kg LPS was injected into a subcutaneous air pouch along with solvent (0.9% saline), or 100 mg/kg pentoxifylline, or 1 mg/animal soluble 55-kD TNF receptor (referred to as TNF-binding protein, TNF bp). The mean LPS-induced concentration of TNF in the lavage of the air pouch (measured 60 min after injection) was 17,765 pg/ml in animals injected with LPS and solvent. This value was reduced to 7,631 pg/ml if pentoxifylline was injected along with LPS into the pouch. If LPS was injected along with TNF bp, no bioactive TNF was detected in the lavage of the air pouch. Simultaneously, TNF was measured in blood plasma. Circulating concentrations of TNF were about 5-8% of the values detected in the lavage of the air pouch (mean values: 1,366 pg/ml in response to LPS plus solvent; 377 pg/ml in response to LPS plus pentoxifylline; no circulating TNF at all in response to LPS plus TNF bp). These data indicated a small spill-over of TNF from the air pouch into the circulation. Neither the reduction of local TNF formation in the air pouch by pentoxifylline nor the complete neutralization of TNF within the pouch by TNF bp resulted in a significant attenuation of the febrile response induced by injection of LPS into the subcutaneous air pouch. If there were an activation of cutaneous nerves to induce fever by a local formation of cytokines within the air pouch, TNF would not represent a likely candidate to be responsible for such a neural stimulation.
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PMID:The role of local induction of tumor necrosis factor by LPS within a subcutaneous air pouch in the development of a febrile response in guinea pigs. 1081 Feb 48

CD137 (ILA/4-1BB), a member of the TNF receptor family, regulates activation, survival and proliferation of primary human monocytes. Here we compare the activities of lipopolysaccharide (LPS), a classical and potent monocyte activator to that of CD137. LPS is a more potent activator of monocytes, as evidenced by a stronger induction of the proinflammatory cytokine IL-8. However, CD137 could further increase maximal cytokine induction by LPS, which points to separate signaling pathways for LPS and CD137. Also, expression of myc was only induced by the combination of CD137 and LPS. Expression of macrophage colony-stimulating factor is induced more potently by CD137, but an additive effect is obtained by the combination of CD137 and LPS. Monocyte/macrophage survival and proliferation is only induced by CD137. LPS counteracts both activities of CD137 via activation induced cell death. While LPS has a role in activation of monocytes in innate immunity, the CD137 receptor/ligand system seems to deliver an activating signal to monocyte in acquired immunity.
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PMID:Comparative analysis of CD137 and LPS effects on monocyte activation, survival, and proliferation. 1087 73

We and others recently reported tumor necrosis factor (TNF) and apoptosis ligand-related leukocyte-expressed ligand 1 (TALL-1) as a novel member of the TNF ligand family that is functionally involved in B cell proliferation. Transgenic mice overexpressing TALL-1 have severe B cell hyperplasia and lupus-like autoimmune disease. Here, we describe expression cloning of a cell surface receptor for TALL-1 from a human Burkitt's lymphoma RAJI cell library. The cloned receptor is identical to the previously reported TNF receptor (TNFR) homologue transmembrane activator and calcium modulator and cyclophilin ligand (CAML) interactor (TACI). Murine TACI was subsequently isolated from the mouse B lymphoma A20 cells. Human and murine TACI share 54% identity overall. Human TACI exhibits high binding affinities to both human and murine TALL-1. Soluble TACI extracellular domain protein specifically blocks TALL-1-mediated B cell proliferation without affecting CD40- or lipopolysaccharide-mediated B cell proliferation in vitro. In addition, when injected into mice, soluble TACI inhibits antibody production to both T cell-dependent and -independent antigens. By yeast two-hybrid screening of a B cell library with TACI intracellular domain, we identified that, like many other TNFR family members, TACI intracellular domain interacts with TNFR-associated factor (TRAF)2, 5, and 6. Correspondingly, TACI activation in a B cell line results in nuclear factor kappaB and c-Jun NH(2)-terminal kinase activation. The identification and characterization of the receptor for TALL-1 provides useful information for the development of a treatment for B cell-mediated autoimmune diseases such as systemic lupus erythematosus.
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PMID:TACI is a TRAF-interacting receptor for TALL-1, a tumor necrosis factor family member involved in B cell regulation. 1088 May 35

Agents that can suppress the activation of nuclear factor-kappaB (NF-kappaB) and activator protein-1 (AP-1) may be able to block tumorigenesis and inflammation. Oleandrin, a polyphenolic cardiac glycoside derived from the leaves of Nerium oleander, is a candidate NF-kappaB and AP-1 modulator. We investigated the effect of oleandrin on NF-kappaB activation induced by inflammatory agents. Oleandrin blocked tumor necrosis factor (TNF)-induced activation of NF-kappaB in a concentration- and time-dependent manner. This effect was mediated through inhibition of phosphorylation and degradation of IkappaBalpha, an inhibitor of NF-kappaB. A proprietary hot water extract of oleander (Anvirzel) also blocked TNF-induced NF-kappaB activation; subsequent fractionation of the extract revealed that this activity was attributable to oleandrin. The effects of oleandrin were not cell type specific, because it blocked TNF-induced NF-kappaB activation in a variety of cells. NF-kappaB-dependent reporter gene transcription activated by TNF was also suppressed by oleandrin. The TNF-induced NF-kappaB activation cascade involving TNF receptor 1/TNF receptor-associated death domain/TNF receptor-associated factor 2/NF-kappaB-inducing kinase/IkappaBalpha kinase was interrupted at the TNF receptor-associated factor 2 and NF-kappaB-inducing kinase sites by oleandrin, thus suppressing NF-kappaB reporter gene expression. Oleandrin blocked NF-kappaB activation induced by phorbol ester and lipopolysaccharide. Oleandrin also blocked AP-1 activation induced by TNF and other agents and inhibited the TNF-induced activation of c-Jun NH2-terminal kinase. Overall, our results indicate that oleandrin inhibits activation of NF-kappaB and AP-1 and their associated kinases. This may provide a molecular basis for the ability of oleandrin to suppress inflammation and perhaps tumorigenesis.
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PMID:Oleandrin suppresses activation of nuclear transcription factor-kappaB, activator protein-1, and c-Jun NH2-terminal kinase. 1091 58

The possibility of maternal in utero modulation of the innate and/or adaptive immune responses of uninfected newborns from Trypanosoma cruzi-infected mothers was investigated by studying the capacity of their whole blood cells to produce cytokines in response to T. cruzi lysate or lipopolysaccharide-plus-phytohemagglutinin (LPS-PHA) stimulation. Cells of such newborns occasionally released gamma interferon (IFN-gamma) and no interleukin-2 (IL-2) and IL-4 upon specific stimulation, while their mothers responded by the production of IFN-gamma, IL-2, and IL-4. Infection in mothers was also associated with a hyperactivation of maternal cells and also, strikingly, of cells of their uninfected neonates, since their release of proinflammatory (IL-1beta, IL-6, and tumor necrosis factor alpha [TNF-alpha]) as well as of anti-inflammatory (IL-10 and soluble TNF receptor) cytokines or factors was upregulated in the presence of LPS-PHA and/or parasite lysate. These results show that T. cruzi infection in mothers induces profound perturbations in the cytokine response of their uninfected neonates. Such maternal influence on neonatal innate immunity might contribute to limit the occurrence and severity of congenital infection.
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PMID:Maternal Trypanosoma cruzi infection upregulates capacity of uninfected neonate cells To produce pro- and anti-inflammatory cytokines. 1094 77

Analysis of gene expression in a mouse model of unilateral ureteral obstruction (UUO) revealed significant induction of CD14 mRNA in kidneys with obstructed ureters. Immunocytochemical analysis indicated that CD14 was upregulated in tubular epithelial cells and this upregulation was not attributable to infiltration of the kidneys by mononuclear cells. This induction of CD14 mRNA was found to occur in BALB/C, C57BL/6, C3H/HeN, and C3H/HeJ mice during UUO. Ischemia/reperfusion of kidneys also induced CD14 mRNA. Mice lacking either of the tumor necrosis factor-alpha receptor (TNFR) genes were also studied; the induction of CD14 was blunted in TNFR 1-knockout mice but not in TNFR2-knockout mice. Apoptosis of tubular cells in lipopolysaccharide-resistant CH3/HeJ mice was significantly (P: < 0. 05) less than that in lipopolysaccharide-responsive CH3/HeN mice during UUO. These results suggest that CD14 is acutely induced in tubular epithelial cells in two mouse models of renal injury. This induction is regulated by tumor necrosis factor-alpha, through TNFR1. CD14 may participate in the apoptosis of tubular epithelial cells on a more chronic basis by activating a pathway that is absent or deficient in C3H/HeJ mice.
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PMID:Induction of CD14 in tubular epithelial cells during kidney disease. 1096 93

Intraperitoneal lipopolysaccharide (LPS) produces somatic hyperalgesia, releases interleukin (IL)-1beta and tumor necrosis factor-alpha (TNF-alpha), and activates vagal afferents. The aim of this study was to evaluate the effect of peripheral LPS on rectal sensitivity and to specify the mechanisms involved. Abdominal muscle contractions were recorded in conscious rats equipped with intramuscular electrodes. Rectal distension (RD) was performed at various times after LPS or experimental treatments. In controls, RD significantly increased the number of abdominal contractions from a threshold volume of distension of 0.8 ml. At the lowest volume (0.4 ml), this number was increased after administration of LPS (3, 9, and 12 h later), recombinant human IL-1beta (from 3 to 9 h), recombinant bovine TNF-alpha (from 6 to 9 h), and BrX-537A (from 6 to 12 h), a mast cell degranulator. The effect of LPS was reduced by doxantrazole, Lys-D-Pro-Thr, and soluble recombinant TNF receptor. Vagotomy selectively amplified the response to LPS. We conclude that, in vivo, intraperitoneal LPS lowers visceral pain threshold (allodynia) through a mechanism involving mast cell degranulation and IL-1beta and TNF-alpha release and that the vagus nerve may exert a tonic protective role against LPS-induced rectal allodynia.
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PMID:Systemic lipopolysaccharide influences rectal sensitivity in rats: role of mast cells, cytokines, and vagus nerve. 1100 66

Endothelial cell damage of glomeruli and kidney arterioles seems to play a pivotal role in several pathologic situations, such as Gram-negative sepsis, glomerulonephritis, and acute renal failure. Bacterial lipopolysaccharide (LPS) and tumor necrosis factor-alpha (TNF-alpha) have been identified as potent inducers of apoptotic cell death in bovine glomerular endothelial cells. Both agents elicited apoptotic DNA laddering within 12 to 24 h. Basic fibroblast growth factor (bFGF) was generally described as a protective factor for endothelial cells against radiation-, TNF-alpha-, and UV-light-induced programmed cell death. Therefore, whether bFGF also affects apoptosis of microvascular endothelial cells was questioned. Surprising was that simultaneous treatment of glomerular endothelial cells with bFGF and either LPS or TNF-alpha left LPS-induced death unaffected, whereas TNF-alpha-induced death induction was potentiated, amounting to 48.9+/-6.3% versus 22.4+/-4.3% DNA degradation with TNF-alpha alone. Comparably, acidic FGF also selectively potentiated TNF-alpha-induced apoptosis. In mechanistic terms, bFGF synergistically increased TNF-alpha-induced mitochondrial permeability transition, the release of cytochrome c from mitochondria to the cytosol, and upregulation of the proapoptotic protein Bak and significantly enhanced activation of caspase-8 protease activity. In contrast, stress-activated protein kinase and nuclear factor kappaB activation, which represent primary signals of TNF/TNF receptor interaction, downregulation of the antiapoptotic protein Bcl-x(L), and caspase-3-like protease activation, were unaffected. As bFGF did not affect LPS-induced apoptotic cell death, bFGF also left LPS-induced Bak upregulation and Bcl-x(L) downregulation unaffected. The results point to a selective bFGF-mediated enhancement of distinct proapoptotic pathways induced by TNF-alpha in glomerular endothelial cells.
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PMID:Basic fibroblast growth factor selectively enhances TNF-alpha-induced apoptotic cell death in glomerular endothelial cells: effects on apoptotic signaling pathways. 1109 43

We previously reported that intracolonic administration of enprostil, a prostaglandin-E(2) (PGE(2)) analogue, had therapeutic effects on acute colitis induced in rodents by dextran sulfate sodium (DSS). In addition, production of growth-regulated gene product/cytokine-induced neutrophil chemoattractant-1 [GRO/CINC-1; an interleukin(IL)-8 like cytokine] was suppressed in the inflamed tissues. In the present study we used a human colon cancer cell line (HT-29) to investigate enprostil effects on the IL-8 production of intestinal epithelial cells stimulated by various stimulants. In a MTT assay, concentrations of enprostil >10(-5)M had cytotoxitic effects on HT-29 cells. Furthermore, 10(-6) M enprostil suppressed IL-8 production in HT-29 cells, SW620 and CaCo2 stimulated with interleukin-1 beta (IL-1 beta) or lipopolysaccharide (LPS), but did not suppress this response when cells were stimulated with tumour necrosis factor (TNF)-alpha. These results suggest that enprostil affects a point in the pathway between the IL-1 receptor or LPS receptor and nuclear factor-kappa B(NF-kappa B), without affecting the pathway between the TNF receptor and NF-kappa B, with the latter factor being required for the IL-8 gene transcription. The therapeutic effect of exogenous enprostil on DSS colitis may involve the inhibition of IL-8 production in colonic epithelial cells stimulated by IL-1 beta or LPS.
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PMID:Enprostil, a prostaglandin-E(2) analogue, inhibits interleukin-8 production of human colonic epithelial cell lines. 1111 62

Interleukin-1 (IL-1) mediates symptoms of sickness during the host response to infection. IL-1 exerts its effects via several subtypes of receptors. To assess the role of IL-1 receptor type I (IL-1RI) in the sickness-inducing effects of IL-1, IL-1beta and the cytokine inducer lipopolysaccharide were administered to IL-1RI-deficient mice (IL-1RI-/-). Sickness was assessed by depression of social exploration, anorexia, immobility and body weight loss. IL-1RI-/- mice were resistant to the sickness-inducing effects of IL-1beta administered intraperitoneally (2 microg/mouse) and intracerebroventricularly (2 ng/mouse), but still fully responsive to lipopolysaccharide administered intraperitoneally (2.5 microg/mouse) and intracerebroventricularly (3 ng/mouse). The sensitivity of IL-1RI-/- mice to lipopolysaccharide was not due to a higher brain expression of proinflammatory cytokines other than IL-1, since lipopolysaccharide-induced expression of brain IL-1 beta, tumour necrosis factor-alpha (TNF-alpha) and IL-6 transcripts were identical in IL-1RI-/- and control mice when measured by semiquantitative reverse-transcriptase polymerase chain reaction 1 h after treatment. Blockade of TNF-alpha action in the brain by intracerebroventricular administration of a fragment of the soluble TNF receptor, TNF binding protein (3.6 microg/mouse), attenuated the depressive effects of intraperitoneal injection of lipopolysaccharide (1 microg/mouse) on behaviour in IL-1RI-/- but not in control mice. Since IL-1RI-/- mice were not more sensitive to intracerebroventricularly TNF-alpha (50 ng) than control mice, these results indicate that IL-1RI mediates the sickness effect of IL-1 and that TNF-alpha simply replaces IL-1 when this last cytokine is deficient.
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PMID:Role of interleukin-1beta and tumour necrosis factor-alpha in lipopolysaccharide-induced sickness behaviour: a study with interleukin-1 type I receptor-deficient mice. 1112 55


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