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)

Pentamidine is an antiprotozoal drug with additional antiinflammatory activities that are not well understood. We now report that pentamidine inhibited the human whole blood production of the chemotactic cytokines (chemokines) interleukin (IL)-8, growth related gene alpha (GRO alpha) and monocyte chemotactic protein-1 (MCP-1). The title compound dose-dependently suppressed the lipopolysaccharide (LPS)- and phytohemagglutinin (PHA)-stimulated whole blood generation of these chemokines with IC50-values of 2.1 and 2.2 microM (IL-8), 2.4 and 1.8 microM (GRO alpha) and 2.8 and 2.4 microM (MCP-1). The inhibition was specific: when tested at 10 microM, pentamidine had no significant inhibitory effect on the PHA-induced generation of the non-chemotactic cytokines tumor necrosis factor-alpha (TNF-alpha), IL-1 beta, IL-2, IL-4, IL-5, IL-10 and interferon-gamma (IFN-gamma), except for a partial inhibition on IL-6. Time course experiments indicated that pentamidine (10 microM) retained its ability to inhibit PHA-stimulated IL-8 production even when its addition was delayed for up to 24h after mitogen stimulation. Furthermore, reverse transcription PCR studies showed that pentamidine had no effect on IL-8 mRNA expression. These findings indicate that pentamidine is a post-transcription acting inhibitor of human chemokine production. This activity may contribute to the anti-inflammatory action ascribed to the title compound.
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PMID:The inhibitory effect of pentamidine on the production of chemotactic cytokines by in vitro stimulated human blood cells. 884 38

Chemokines constitute a family of low-molecular-weight proteins that attract or activate a variety of cell types, including leukocytes, endothelial cells, and fibroblasts. An electronic search of the GenBank Expressed Sequence Tags database uncovered a partial cDNA sequence with homology to the chemokine monocyte chemotactic protein-1 (MCP-1). Isolation of the full-length clone revealed that it encodes the chemokine MCP-4, an eosinophil chemoattractant recently described by Uguccioni et al. [J. Exp. Med. 183, 2379-2384]. Recombinant MCP-4 was expressed in mammalian cells and purified by heparin-Sepharose chromatography. Sequencing the amino terminus of this protein corroborated the reported sequence of recombinant MCP-4 produced in insect cells. As shown by calcium flux assays, MCP-4 activated the cloned G protein-coupled receptor CCR-2, which also recognizes MCP-1 and MCP-3. Northern hybridization indicated that MCP-4 is constitutively expressed at high levels in the small intestine, colon, and lung. This expression profile is consistent with its role as a chemoattractant for eosinophils, which can be rapidly mobilized to the lung or intestine in response to invading pathogens. In marked contrast to MCP-1, MCP-4 was not induced in cell lines treated with pro-inflammatory stimuli such as lipopolysaccharide or tumor necrosis factor alpha.
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PMID:Monocyte chemotactic protein-4: tissue-specific expression and signaling through CC chemokine receptor-2. 906 Apr 59

The aim of this study was to determine the relative production of chemokines interleukin-8 (IL-8), regulated on activation, normal T-cell expressed and secreted (RANTES) and monocyte chemotactic protein-1 (MCP-1) by intrinsic and extrinsic asthmatics. Nine intrinsic asthmatics, 10 extrinsic asthmatics, five nonatopic and five atopic controls underwent bronchoalveolar lavage (BAL). Total BAL cells were cultured in the presence or absence of lipopolysaccharide. Chemokines were measured in BAL cell supernatants and in cell-free bronchoalveolar lavage fluid (BALF) by enzyme-linked immunoabsorbent assay (ELISA). BAL cell cytospins were stained immunohistochemically for chemokines. BAL cells from asthmatics produced more IL-8 than controls (statistically significant for extrinsic asthma). RANTES was elevated in the BAL cell supernatants of four out of nine intrinsic asthmatics as compared to nonatopic controls (not statistically significant). RANTES levels in the BAL cell supernatants of extrinsic asthmatics were all low. MCP-1 production by BAL cells was similar in all groups. Immunostaining of BAL cell cytospins showed the macrophage to be the predominant positive-staining cell type and correlated well with supernatant data. Measurement of chemokines in BALF showed significantly elevated IL-8 in intrinsic asthma compared to nonatopic controls, but no increase in extrinsic asthmatics relative to atopic control RANTES was elevated in three out of nine BALFs from intrinsic asthmatics compared with nonatopic controls (not statistically significant). MCP-1 was not elevated above control levels in BALF of either asthma group. These results suggest an up-regulation in the production of interleukin-8 and regulated on activation, normal T-cell expressed and secreted, but not monocyte chemotactic protein-1 (MCP-1), by macrophages in the bronchoalveolar lavage of asthmatic subjects. In addition, the data suggest that regulated on activation, normal T-cell, expressed and secreted, may be differentially produced by macrophages in atopic and nonatopic asthma.
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PMID:Production of interleukin-8, RANTES and MCP-1 in intrinsic and extrinsic asthmatics. 931 10

During inflammatory and immunological responses, leukocytes respond to external stimuli by altering the stability of cytokine and cytokine receptor messages. Change in message stability is an effective mechanism for rapidly regulating steady state levels of mRNA. Cytokine messages containing A-U-rich elements located in the 3' untranslated region (ARE) are the best studied examples of this process. AREs have been shown to act as targeting motifs for degradation of cytokine and transcription factor messages. We have recently observed that the interleukin-8 (IL-8) receptor messages, IL-8RA and B (CXCR1 and CXCR2), also undergo changes in stability in response to the inflammatory stimulator lipopolysaccharide (LPS). To determine whether regulation of message stability is a common mechanism for modulation of chemokine receptor mRNA we explored whether the stability of the CC chemokine receptor message for CCR2 (monocyte chemotactic protein-1 receptor) is also regulated by LPS. We found that LPS induces a rapid loss of steady state levels of CCR2 message through message degradation. Furthermore, LPS stimulated the decay of Poly(A) CCR2 mRNA faster than total CCR2 RNA, indicating that deadenylation is the first step in LPS-induced CCR2 RNA degradation. We conclude from these experiments that LPS stimulates the rapid degradation of CCR2 messages through a two-step process, deadenylation followed by degradation of the message body. In contrast to the results obtained for CCR2 mRNA, macrophage inflammatory protein-1alpha messages, which contain an ARE motif, were stabilized by LPS stimulation, indicating that chemokine and chemokine receptor mRNA stability are regulated by different and opposing mechanisms.
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PMID:Regulation of CCR2 chemokine receptor mRNA stability. 936 20

PTX3 is a prototypic long pentraxin expressed by various cell types, most prominently monocytes and endothelial cells, in response to interleukin-1 (IL-1), tumor necrosis factor (TNF) and bacterial products. In the present report, we show that interferon-gamma (IFN-gamma) inhibits the expression of the PTX3 gene induced by exposure to IL-1, TNF or lipopolysaccharide in human monocytes. This effect is dose dependent and observable when IFN-gamma is added from 24 h before up to 3 h after the addition of IL-1. While the time course of the IL-1-induced PTX3 mRNA expression is not affected, IFN-gamma reduces the stability of the PTX3 mRNA as well as its transcription. The inhibition of PTX3 expression is restricted to monocytes in that no inhibition occurs in cytokine-stimulated fibroblasts and endothelial cells. Under the same conditions, as expected, IFN-gamma augmented monocyte chemotactic protein-1 expression in the same cell preparations. PTX3 protein secretion by activated monocytes is also suppressed by exposure to IFN-gamma. Altogether, these data identify a negative pathway of regulation mediated by IFN-gamma, which may occur under inflammatory conditions.
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PMID:Interferon-gamma inhibits expression of the long pentraxin PTX3 in human monocytes. 952 Oct 58

Orbital inflammation is common, but the mechanisms underlying leukocytic infiltration of orbital tissue are poorly understood. We studied resident human orbital fibroblasts (OF) interleukin-8 (IL-8), and monocyte chemotactic protein-1 (MCP-1) mRNA expression and protein secretion in response to lipopolysaccharide (LPS) or recombinant human cytokines that are present during inflammation. Third-passaged cultured human OF were left unstimulated or incubated with varying concentrations of LPS, recombinant interleukin-1-beta (rIL-1 beta), recombinant tumor necrosis factor-alpha (rTNF-alpha), or recombinant interferon-gamma (rIFN-gamma) for 2, 4, 8, or 24 h. Northern blot analysis and ELISA were performed to determine OFIL-8 and MCP-1 mRNA expression and protein secretion, respectively. Experiments were performed in triplicate and repeated four times on different cell lines. OF lacked constitutive IL-8 or MCP-1 gene expression, but produced substantial dose-dependent increases in steady-state IL-8 and MCP-1 mRNA expression by 2 h of LPS or cytokine stimulation (rIL-1 beta > fTNF-alpha > LPS > rIFN-gamma), maintained at 24 h ELISA for IL-8 and MCP-1 proteins showed significant time- and dose-dependent OF secretion after exposure to recombinant cytokine or LPS (rIL-1 beta > rTNF-alpha > LPS), measured after 4 h of exposure (p < 0.01). This increased in the media over the next 20 h. rIFN-gamma was a potent stimulant of OF MCP-1, significant by 2 h (p < 0.05), but only a weak stimulant of IL-8 at 24 h. OF secreted IL-8 and MCP-1 in response to LPS and proinflammatory cytokines, indicating that these resident cells within the orbit have the capacity to actively participate in the initiation and propagation of orbital inflammation. Strategies aimed at modulating local mediators may be helpful in the management of orbital inflammatory disease.
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PMID:Interleukin-8 and monocyte chemotactic protein-1 gene expression and protein production by human orbital fibroblasts. 955 69

The production of cytokines and chemokines, which are involved in cell activation and cell migration in native pieces of peritoneum, was measured to investigate immune regulatory reactions in the human peritoneum. The samples were obtained during abdominal surgery and cultured immediately afterwards. In order to test therapeutic options in vitro, the effect of IL-10 and IFN-gamma on the cytokine and chemokine production was also studied. The chemokine monocyte chemotactic protein-1 (MCP-1) was produced and released spontaneously. When lipopolysaccharide (LPS) was added, MCP-1 production increased. In addition, TNF-alpha production was induced by LPS. When IL-10 was added, LPS-stimulated TNF-alpha production was reduced towards baseline levels, LPS-induced MCP-1 production was reduced by 37%. IFN-gamma did not affect LPS-induced TNF-alpha and MCP-1 production, but increased baseline MCP-1 production. It can be concluded that short-time culture of native human peritoneum is a method to investigate peritoneal chemokine and cytokine production in patients undergoing abdominal surgery. Further studies are intended to detect cytokine patterns which identify patients at risk of developing peritonitis. In addition, the effects of medications may be tested in vitro in order to investigate options for preventive modulation of the peritoneal immune response in such patients.
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PMID:Culture of human peritoneum--a new method to measure the local cytokine response and the effect of immunomodulators. 979 4

Recent evidence has suggested that epithelial cells may contribute to the inflammatory response in the lung after exposure to crystalline silica through the production of and response to specific growth factors, chemokines, and cytokines. However, the exact cellular and molecular responses of epithelial cells to silica exposure remains unclear. Using a murine alveolar type II cell line [murine lung epithelial (MLE)-15 cell line], we measured the early changes in various cytokine and chemokine mRNA species after exposure of the cells to 4-35 microgram/cm2 of silica (cristobalite), interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, and lipopolysaccharide (LPS) alone or in combination. Total mRNA was isolated and assayed with an RNase protection assay after 6 and 24 h of exposure. Cristobalite exposure alone led to an increase in monocyte chemotactic protein (MCP)-1, macrophage inflammatory protein (MIP)-2, and regulated on activation normal T cells expressed and secreted (RANTES) mRNAs. Treatment with IFN-gamma alone increased MCP-1 mRNA levels. Treatment with TNF-alpha or LPS alone led to an increase in MCP-1 and MIP-2 mRNA. The combination of cristobalite plus TNF-alpha led to an additive increase in MCP-1 and MIP-2, whereas cristobalite plus IFN-gamma or LPS had a synergistic effect. We also found with a TNF-alpha-neutralizing antibody that TNF-alpha plays a major role in mediating the type II cell chemokine response to cristobalite exposure. The results indicate that the cristobalite-induced chemokine response in the lung epithelium is mediated in part by TNF-alpha and can be enhanced by macrophage- and lymphocyte-derived inflammatory mediators in an additive and synergistic fashion.
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PMID:Silica-induced chemokine expression in alveolar type II cells is mediated by TNF-alpha. 984 48

We have examined the biological activity of the CC chemokine myeloid progenitor inhibitory factor 1 (MPIF-1) on human dendritic cells. MPIF-1 has chemotactic activity on dendritic cells derived from either peripheral blood monocytes or cord blood CD34+ progenitors. However, chemokine treatment did not induce further cell activation or maturation. In addition, MPIF-1 is constitutively released by monocyte-derived dendritic cells but not macrophages or monocytes (resting or stimulated). The proinflammatory stimuli lipopolysaccharide and tumor necrosis factor alpha, which induced the release of monocyte chemotactic protein-1, macrophage inflammatory protein-1alpha (MIP-1alpha), MIP-1beta, and interleukin-8, did not affect MPIF-1 release. In contrast, CD40 ligation and interferon-gamma treatment, while stimulating the production of the other chemokines, caused a pronounced reduction of MPIF-1 transcript and protein release. Thus, in dendritic cells the regulation of the production and release of MPIF-1 is distinct in comparison to other CC and CXC chemokines.
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PMID:Dendritic cells and MPIF-1: chemotactic activity and inhibition of endogenous chemokine production by IFN-gamma and CD40 ligation. 1038 Sep 5

Selected phosphorothioate oligodeoxynucleotides containing CpG (CpG-ODN) activate immune responses, including immunoglobulin synthesis, B cell proliferation, and cytokine production by monocytes. We examined the effect of a CpG-ODN (#1760) on the adhesion of macrophages derived from human blood monocytes in vitro. CpG-ODN (6 microg/mL) completely inhibited the adherence of macrophages to plastic or glass during 7 or more days of culture. A non-CpG control ODN (#1814) was without effect. Two other CpG-ODNs (#1826 and #1842) also completely inhibited macrophage adherence. The specific inhibitor of CpG-ODN, quinacrine (0.1 micromol/L), blocked this action. CpG-ODN reduced the rate of senescence and cell death of monocytes in culture but did not influence their phagocytosis, procoagulant activity, or support of the mixed lymphocyte response. Four days of exposure of monocytes to CpG-ODN up-regulated the expression of the endotoxin receptor CD14 and down-regulated the mannose (scavenger) receptor, a result that is consistent with blocking the maturation of monocytes to macrophages. Incubation of peripheral blood monocytes (PBMCs) with CpG-ODN resulted in the generation of a heat labile factor that inhibited macrophage differentiation and accounts for the efficacy of the CpG-ODN. T cells selected from PBMCs by magnetic beads generated the majority of this factor. Cytokines (interleukin-3 (IL-3), IL-4, IL-6, IL-10, interferon-gamma, tumor necrosis factor-alpha, transforming growth factor-beta, granulocyte-macrophage colony-stimulating factor, monocyte chemotactic protein-1) did not inhibit macrophage adherence like CpG-ODN did. Antibodies to IL-6 or IL-10 did not block the activity of CpG-ODN. Dexamethasone inhibited macrophage adherence, and lipopolysaccharide had a minor effect. We conclude that immunostimulatory CpG-ODNs inhibit macrophage adherence by provoking the production of an unidentified heat-labile factor.
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PMID:Immunostimulatory CpG-oligodeoxynucleotides induce a factor that inhibits macrophage adhesion. 1056 Sep 44


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