Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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 this study, self-organizing map (SOM) gene cluster techniques are applied to the analysis of cDNA microarray analysis of gene expression changes occurring in the early stages of genitourinary inflammation. We determined the time course of lipopolysaccharide (LPS)-induced gene expression in experimental cystitis. Mice were euthanized 0.5, 1, 4, and 24 h after LPS instillation into the urinary bladder, and gene expression was determined using four replicate Atlas mouse cDNA expression arrays containing 588 known genes at each time point. SOM gene cluster analysis, performed without preconditions, identified functionally significant gene clusters based on the kinetics of change in gene expression. Genes were classified as follows: 1) expressed at time 0; 2) early genes (peak expression between 0.5 and 1 h); and 3) late genes (peak expression between 4 and 24 h). One gene cluster maintained a constant level of expression during the entire time period studied. In contrast, LPS treatment downregulated the expression of some genes expressed at time 0, in a cluster including transcription factors, protooncogenes, apoptosis-related proteins (cysteine protease), intracellular kinases, and growth factors. Gene upregulation in response to LPS was observed as early as 0.5 h in a cluster including the interleukin-6 (IL-6) receptor, alpha- and beta-nerve growth factor (alpha- and beta-NGF), vascular endothelial growth factor receptor-1 (VEGF R1), C-C chemokine receptor, and P-selectin. Another tight cluster of genes with marked expression at 1 h after LPS and insignificant expression at all other time points studied included the protooncogenes c-Fos, Fos-B, Fra-2, Jun-B, Jun-D, and Egr-1. Almost all interleukin genes were upregulated as early as 1 h after stimulation with LPS. Nuclear factor-kappaB (NF-kappaB) pathway genes collected in a single cluster with a peak expression 4 h after LPS stimulation. In contrast, most of the interleukin receptors and chemokine receptors presented a late peak of expression 24 h after LPS coinciding with the peak of neutrophil infiltration into the bladder wall. Selected cDNA microarray observations were confirmed by RNase protection assay. In conclusion, the cDNA array experimental approach provided a global profile of gene expression changes in bladder tissue after stimulation with LPS. SOM techniques identified functionally significant gene clusters, providing a powerful technical basis for future analysis of mechanisms of bladder inflammation.
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PMID:Time course of LPS-induced gene expression in a mouse model of genitourinary inflammation. 1128 68

Calprotectin, a heterodimer of MRP8 and MRP14 with antimicrobial properties, is found in the cytosol of neutrophils, monocytes, and human gingival keratinocytes. During inflammation of the oral mucosa, the expression of immunoreactive calprotectin appears upregulated. Given the possible cell sources, we sought to learn if epithelial cells upregulate calprotectin in response to proinflammmatory agents. First, human gingival keratinocytes were maintained in primary culture until senescence. At each passage, cells were harvested and analyzed for quantitative expression of MRP8 and MRP14 subunit mRNA by RNase protection assays and calprotectin complex by enzyme-linked immunosorbent assay. Calprotectin expression was constitutive in the primary gingival keratinocytes, but calprotectin-specific mRNA and protein tended to increase as the cells neared senescence. To test whether calprotectin expression was inducible, immortalized gingival keratinocyte cultures were treated for 2 to 4 h with lipopolysaccharide (LPS) or interleukin-1 beta (IL-1 beta). As a positive control for inducible expression, immortalized keratinocytes were incubated with phorbol myristate acetate (PMA) (50 ng/ml) for 24 h. Incubation with PMA stimulated increased expression of MRP8 and MRP14 mRNA within 2 h, peaking within 5 h. MRP8- and MRP14-specific mRNA expression by immortalized keratinocytes appeared to be unaffected by LPS or IL-1 beta. In contrast, LPS, IL-1 beta, and PMA each upregulated IL-8. These data show that calprotectin mRNA is expressed constitutively in cultured keratinocytes, while expression by immortalized cells appears to be independent of the exogenous proinflammatory agents LPS and IL-1 beta.
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PMID:Calprotectin expression by gingival epithelial cells. 1129 47

Tumor necrosis factor (TNF)-alpha plays a key role in the pathogenesis of septic shock syndrome, and myocardial TNF-alpha expression may contribute to this pathophysiology. We examined the myocardial expression of TNF-alpha-related cytokines and chemokines in mice exposed to lipopolysaccharide (LPS) and tested the effects of anti-TNF therapy on myocardial cytokine expression. Cytokine mRNA levels were measured by RNase protection assay, and protein levels in the plasma and myocardium were assessed by enzyme-linked immunosorbent assays. LPS (4 microg/g body wt ip) induced marked cytokine expression, including TNF-alpha, interleukin (IL)-1beta, IL-6, and monocyte chemotactic protein (MCP)-1, in both the plasma and myocardium. Pretreatment with adenovirus-mediated TNF receptor fusion protein (AdTNFR1; 10(9) plaque-forming units iv) decreased plasma cytokine levels. In contrast, whereas myocardial IL-1beta expression was also suppressed, expression of IL-6 and MCP-1 was not inhibited by AdTNFR1. In summary, anti-TNF treatment differentially altered the cytokine expression in the plasma and myocardium during endotoxemia. Inability to block myocardial expression of IL-6 and MCP-1 suggests a possible mechanism for the failure of anti-TNF therapies in the treatment of endotoxin shock.
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PMID:Effects of soluble TNF receptor treatment on lipopolysaccharide-induced myocardial cytokine expression. 1129 32

Interleukin-12 (IL-12) is a monocyte/macrophage-derived cytokine that plays a prominent role in the development of T helper type 1 (Th1) cell-mediated immune responses. Glycyrrhizin (GL), an aqueous extract of liquorice root, used as Chinese medicine, is known to have various immunomodulating activities. In this study, GL showed a dose-dependent priming effect on lipopolysaccharide (LPS)-induced IL-12 p40 and IL-12 p70 (heterodimer of p40 and p35) protein production by peritoneal macrophages (PM). The maximal effect was observed when GL was intraperitoneally administered 12 hr before the PM were harvested and stimulated in vitro with LPS. The increases in IL-12 p70 and p40 protein production were primarily due to up-regulated transcription of IL-12 p35 and p40 messenger RNAs (mRNAs), as demonstrated by RNase protection assay. The augmentation of IL-12 p40 mRNA expression induced by GL pretreatment was associated with increased NF-kappaB activation. Moreover, GL exhibited the same priming effect on IL-12 production in interferon-gamma knockout (IFN-gamma-/-) mice. The production of granulocyte-macrophage colony-stimulating factor (GM-CSF) was not induced at any time point after GL pretreatment. These findings demonstrated the ability of GL to enhance LPS-induced IL-12 production by peritoneal macrophages, and indicated that the priming effect of GL on IL-12 production was independent of both IFN-gamma and GM-CSF.
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PMID:Glycyrrhizin enhances interleukin-12 production in peritoneal macrophages. 1141 11

Macrophages form a crucial bridge between the innate and adaptive immune response. One of their most important functions is to recognize infectious microorganisms. Toll-like receptors (TLRs) are key elements in pathogen recognition, and among them, TLR2 and TLR4 are most discussed. However, expression patterns of TLRs during myeloid cell differentiation to macrophage are unknown. In this study, we examined differentiation in the model human myeloid cell line, HL-60, treated with phorbol 12-myristate 13-acetate (PMA) or VitD(3). Expression of TLR2, TLR4, and CD14 were measured by reverse transcription-PCR, RNase protection assay, and fluorescence-activated cell sorter assays. After treatment by PMA (1, 10, and 100 nM) for 12, 24, and 48 h, expression of TLR2 and CD14 mRNA was increased in a time- and dose-dependent manner. However, VitD(3) only induced expression of CD14 but not TLR2 in HL-60 cells. TLR4 was expressed constitutively before differentiation and increased slightly after that. Thus, PMA-mediated differentiation of HL-60 cells to macrophages is associated largely with TLR2 expression and, to a much lesser extent, with TLR4. Furthermore, up-regulation of TLR2 and CD14 mRNA expression by PMA was abrogated by a protein kinase C inhibitor, Calphostine C, suggesting the up-regulation of TLR2 and CD14 mRNA is dependent on the activation of protein kinase C. Coexpression of CD14/TLR2 and/or CD14/TLR4 may be essential but not sufficient for the production of tumor necrosis factor-alpha in response to lipopolysaccharide in our system.
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PMID:Expression of toll-like receptors 2 and 4 and CD14 during differentiation of HL-60 cells induced by phorbol 12-myristate 13-acetate and 1 alpha, 25-dihydroxy-vitamin D(3). 1180 29

Acute ethanol administration temporarily decreases the sensitivity to endotoxin (lipopolysaccharide, LPS) in the liver. The purpose of this study was to investigate the changes of toll-like receptor (TLR)-4, a newly identified LPS receptor in macrophages, in the liver following acute ethanol administration. Male C57BL/6N mice were given a bolus intragastric administration of ethanol (5 mg/g BW) through a gastric canula, and liver samples were obtained 2-48 h later. RAW264.7 macrophages were cultured in the presence of ethanol (100 mM) or LPS (10 ng/ml) for up to 4 h. TLR-4 mRNA in the liver and RAW264.7 cells was detected by RNase protection assay. As expected, TLR-4 mRNA was clearly detected in the control liver; however, it was barely detectable in the liver 2-6 h after ethanol administration, followed by the gradual increase to the basal levels 48 h later. Interestingly, LPS (10 ng/ml), but not ethanol (100 mM), decreased TLR-4 mRNA in RAW264.7 macrophages in 4 h. Indeed, gut-sterilization by oral antibiotics pretreatment prevented the decrease in TLR-4 mRNA caused by acute ethanol administration, supporting the hypothesis that gut-derived endotoxin is involved in the mechanism. These findings clearly indicated that acute ethanol administration in vivo down-regulates TLR-4 expression in the liver. This phenomenon most likely explains the mechanism by which acute ethanol blunts the response of Kupffer cells to LPS transiently.
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PMID:Acute ethanol administration down-regulates toll-like receptor-4 in the murine liver. 1204 67

The tetraspanins are a family of integral membrane proteins with four transmembrane domains. These molecules form multimolecular networks on the surfaces of many different cell types. Gene-targeting studies have revealed a role for tetraspanins in B- and T-lymphocyte function. We have isolated and deleted a novel tetraspanin, Tssc6, which is expressed exclusively in hematopoietic and lymphoid organs. Using a gene-trapping strategy, we generated an embryonic stem (ES) cell line with an insertion in the Tssc6 locus. Mice were derived from these ES cells and, using RNase protection and reverse transcription-PCR, we demonstrated that the insertion resulted in a null mutation of the Tssc6 allele. Mice homozygous for the gene trap insertion (Tssc6(gt/gt) mice) were viable and fertile, with normal steady-state hematopoiesis. Furthermore, responses to hemolysis and granulocyte colony-stimulating factor-induced granulopoiesis were equivalent to those of wild-type mice. Lymphoid development was normal in Tssc6(gt/gt) mice. Whereas Tssc6(gt/gt) B cells responded normally to lipopolysaccharide, anti-CD40, and anti-immunoglobulin M stimulation, Tssc6(gt/gt) T cells showed enhanced responses to concanavalin A, anti-CD3, and anti-CD28. This increased proliferation by Tssc6-deleted T lymphocytes was due to increased interleukin 2 production following T-cell receptor stimulation. These results demonstrate that Tssc6 is not required for normal development of the hematopoietic system but may play a role in the negative regulation of peripheral T-lymphocyte proliferation.
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PMID:The absence of Tssc6, a member of the tetraspanin superfamily, does not affect lymphoid development but enhances in vitro T-cell proliferative responses. 1207 30

A new murine member of the interferon (IFN)-inducible guanylate-binding protein (GBP) family was cloned in a search for glucocorticoid-attenuated response genes induced in the lung during endotoxemia. The full-length MuGBP-5 cDNA encodes a 590 amino acid residue protein with GTP binding motifs identical to those in human GBP-1 (HuGBP-1) and a similar isoprenylation sequence at the C-terminus. An alternatively spliced form of MuGBP-5 that lacks the second GTP binding motif and differs at the C-terminus was also identified. The MuGBP-5 gene is located on chromosome 3, near MuGBP-3 and MuGBP-2, and has a genomic organization similar to other GBP genes. To facilitate the evaluation of GBP family message expression, we constructed RNase protection assay probes for MuGBP-1, MuGBP-2, MuGBP-3, MuGBP-4/Mag-2 (macrophage activation gene-2), and MuGBP-5 and validated their use in Swiss Webster, BALB/c, and C57BL/6 mice. In BALB/c mice, all five MuGBPs were induced in multiple organs during endotoxemia, and all had a similar pattern of expression in different tissues. With minor quantitative differences, the MuGBPs also had similar patterns of response to IFN-gamma, lipopolysaccharide (LPS), interleukin-1beta (IL-1beta), and tumor necrosis factor-alpha (TNF-alpha) in RAW 264.7 and Swiss 3T3 cells. The coordinate expression of the MuGBPs suggests that they share common mechanisms of regulation.
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PMID:Murine GBP-5, a new member of the murine guanylate-binding protein family, is coordinately regulated with other GBPs in vivo and in vitro. 1239 30

The aim of the present study was to evaluate the anti-inflammatory activity of pre-elafin, an elastase-specific inhibitor, in lipopolysaccharide (LPS)-induced acute lung inflammation. C57BL/6 mice were pre-treated intranasally with recombinant human pre-elafin or vehicle only. One hour later, they were instilled intranasally with LPS (2 microg/mouse). Animals were sacrificed 6 hours after LPS instillation and bronchoalveolar lavage (BAL) was performed with three 1-ml aliquots of saline. LPS induced a lung inflammation characterised by a 100-fold increase in BAL neutrophils compared to control animals (265.8 +/- 54.5 x 10(3) and 2.4 +/- 1.3 x 10(3) neutrophils/ml, respectively). Pre-elafin dose-dependently reduced the neutrophil influx in the lung alveolar spaces by up to 84%. No elastase activity was detectable in all BAL fluids tested. Pre-elafin also reduced significantly LPS-induced gelatinase activity, as shown by zymography, and BAL macrophage inflammatory protein-2 (MIP-2) and KC levels, two potent neutrophil attractants and activators. Moreover, pre-elafin also significantly reduced mRNA levels of the three members of the IL-1 ligand family, namely IL-1alpha, IL-1beta and IL-1 receptor antagonist (IL-1Ra), type II IL-1 receptor, and TNFalpha as assessed in whole lung tissue by RNase protection assay. Thus, pre-elafin may be considered as a potent anti-inflammatory mediator.
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PMID:Anti-inflammatory effect of pre-elafin in lipopolysaccharide-induced acute lung inflammation. 1243 12

Human herpesvirus 6 (HHV-6) is a potentially immunosuppressive agent that has been suggested to act as a cofactor in the progression of HIV disease. Exposure of human macrophages to HHV-6A or HHV-6B profoundly impaired their ability to produce interleukin 12 (IL-12) upon stimulation with interferon-gamma (IFN-gamma) and lipopolysaccharide (LPS). By contrast, the production of tumor necrosis factor-alpha (TNF-alpha); regulated on activation, normal T-cell expressed and secreted (RANTES); and macrophage inflammatory protein 1 beta (MIP-1 beta) was not negatively affected. To exclude the involvement of IL-12-suppressive cytokines, such as IL-10 and TNF-alpha, the viral stocks were fractionated by ultra-centrifugation. The bulk of the suppressive activity was recovered within the virion-rich pelleted fraction that was virtually devoid of such cytokines. IL-12 suppression was independent of viral replication, and the effect was not abrogated upon ultraviolet-light inactivation of the viral inoculum. The mechanism of HHV-6-mediated IL-12 suppression was investigated by RNase protection assays, which demonstrated unaltered levels of IL-12 p35 mRNA and only a modest reduction in p40 mRNA, which was insufficient to account for the near-complete loss of both extracellular and intracellular IL-12 protein. Moreover, both the IFN-gamma and the LPS signaling pathways were intact in HHV-6-treated cells. These data suggest that HHV-6 can dramatically affect the generation of effective cellular immune responses, providing a novel potential mechanism of HHV-6-mediated immunosuppression.
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PMID:Selective suppression of IL-12 production by human herpesvirus 6. 1282


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