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)

Extensive studies in the past 10 years have suggested that heat shock protein 60 (Hsp60) and Hsp70 may be potent activators of the innate immune system capable of inducing pro-inflammatory cytokine production by macrophages. However, we have recently demonstrated that the reported pro-inflammatory cytokine-inducing effect of Hsp60 and Hsp70 was due to contaminating lipopolysaccharide (LPS) and LPS-associated molecules. In the current study, we determined whether highly purified, essentially LPS-free recombinant human Hsp60 (rhHsp60) and rhHsp70 had any cytokine-inducing effect. Using gene expression array, we demonstrated that at 2 and 4h after treatment, while LPS (1 ng/ml) markedly enhanced the expression of a number of cytokine genes, rhHsp60 and rhHsp70 (5 microg/ml) had no effect on any of the 96 common cytokine genes. Reverse transcriptase-polymerase chain reaction analysis and enzyme-linked immunosorbent assay of tumor necrosis factor-alpha (TNFalpha) and interleukin-1beta (IL-1beta) supported the above observation. These data suggest that rhHsp60 and rhHsp70 do not activate cytokine genes in murine macrophages.
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PMID:Induction of cytokines by heat shock proteins and endotoxin in murine macrophages. 1509 89

Extrahepatic cholestasis often evokes liver injury with hepatocyte apoptosis, aberrant cytokine production, and-most importantly-postoperative septic complications. To clarify the involvement of aberrant cytokine production and hepatocyte apoptosis in impaired resistance to bacterial infection in obstructive cholestasis, C57BL/6 mice or Fas-mutated lpr mice were inoculated intraperitoneally with 10(7) colony-forming units of Escherichia coli 5 days after bile duct ligation (BDL) or sham celiotomy. Cytokine levels in sera, liver, and immune cells were assessed via enzyme-linked immunosorbent assay or real-time reverse-transcriptase polymerase chain reaction. BDL mice showed delayed clearance of E. coli in peritoneal cavity, liver, and spleen. Significantly higher levels of serum interleukin (IL) 10 with lower levels of IL-12p40 were observed in BDL mice following E. coli infection. Interferon gamma production from liver lymphocytes in BDL mice was not increased after E. coli infection either at the transcriptional or protein level. Kupffer cells from BDL mice produced low levels of IL-12p40 and high levels of IL-10 in vitro in response to lipopolysaccharide derived from E. coli. In vivo administration of anti-IL-10 monoclonal antibody ameliorated the course of E. coli infection in BDL mice. Furthermore, BDL-lpr mice did not exhibit impairment in E. coli killing in association with little hepatic injury and a small amount of IL-10 production. In conclusion, increased IL-10 and reciprocally suppressed IL-12 production by Kupffer cells are responsible for deteriorated resistance to bacterial infection in BDL mice. Fas-mediated hepatocyte apoptosis in cholestasis may be involved in the predominant IL-10 production by Kupffer cells.
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PMID:Kupffer cell-derived interleukin 10 is responsible for impaired bacterial clearance in bile duct-ligated mice. 1536 46

The purpose of this study was to evaluate the kinetic changes and the localization of high-mobility group box 1 protein (HMGB1) and to observe the effect of heat shock response (HSR) on the expression and release of HMGB1 in lipopolysaccharide (LPS)-activated murine macrophage-like RAW 264.7 cells. Reverse transcriptase (RT)-PCR and Western blot were used to examine HMGB1 expression after LPS treatment. The intracellular localization of HMGB1 in normal or LPS-activated cells was investigated by immunocytochemical analysis and HMGB1 released from cultured macrophages by Western blot. HSR was performed by incubating RAW 264.7 cells at 42.5 degrees C for 1 h then recovery at 37 degrees C for 12 h. The effect of HSR on expression and release of HMGB1 was observed. The results showed that a decrease of HMGB1 mRNA expression was observed at 18 h after LPS (500 ng/mL) treatment, although the total intracellular HMGB1 protein levels were not affected. A visible translocation of HMGB1 from the nuclear to the cytoplasm was observed at 20 h after stimulation with LPS (500 ng/mL). Furthermore, HMGB1 was released into the medium by LPS-activated RAW 264.7 cells in a time- and dose-dependent manner. Heat shock pretreatment significantly inhibited LPS-induced release of HMGB1 and the translocation of HMGB1 from the nucleus to the cytoplasm in RAW 264.7 cells. These findings suggest that the release of HMGB1 by LPS-activated macrophages is a late event in the pathogenesis of sepsis and that HSR could inhibit the release and translocation of HMGB1 induced by LPS.
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PMID:Heat shock response inhibits release of high mobility group box 1 protein induced by endotoxin in murine macrophages. 1583 9

Innate immunity is a widespread and important defence against microbial attack, which in insects is thought to originate mainly in the fat body. Here we demonstrate that the fluid-transporting Malpighian (renal) tubule of Drosophila melanogaster constitutes an autonomous immune-sensing tissue utilising the nitric oxide (NO) signalling pathway. Reverse transcriptase PCR (RT-PCR) shows that tubules express those genes encoding components of the Imd pathway. Furthermore, isolated tubules bind and respond to lipopolysaccharide (LPS), by upregulating anti-microbial peptide (diptericin) gene expression and increased bacterial killing. Excised, LPS-challenged tubules, as well as tubules from LPS-infected flies, display increased NO synthase (NOS) activity upon immune challenge. Targetted expression of a Drosophila NOS (dNOS) transgene to only principal cells of the tubule main segment using the GAL4/UAS system increases diptericin expression. In live flies, such targetted over-expression of dNOS to tubule principal cells confers increased survival of the whole animal upon E. coli challenge. Thus, we describe a novel role of Malpighian tubules in immune sensing and insect survival.
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PMID:Insect renal tubules constitute a cell-autonomous immune system that protects the organism against bacterial infection. 1589 91

Intestinal macrophage responses to luminal bacteria and their constituents are important in mucosal inflammatory responses. We investigated the responses of intestinal macrophages to free lipopolysaccharide (LPS) and Escherichia coli. Macrophages were isolated from normal terminal ileum and colon by allowing them to migrate out of the lamina propria of mucosal samples denuded of epithelial cells. Following exposure to free LPS or fluorescein-labelled E. coli, responsiveness was studied by intracellular expression of tumour necrosis factor-alpha (TNF-alpha). CD14, CD33, CD68, TLR2 and TLR4 expression was studied by fluorescence-activated cell sorter (FACS). TLR and NOD2 expression was confirmed by reverse-transcriptase polymerase chain reaction (RT-PCR). CD14 was expressed by 36.5 +/- 4.0% of the macrophages obtained following migration out of the lamina propria. These cells also expressed TLR2, TLR4 and NOD2. Of cells exposed to free LPS or those that had taken up E. coli, a greater proportion of CD14(+) than CD14(-) macrophages expressed intracellular TNF-alpha. Moreover, a greater proportion of macrophages (CD14(+) and CD14(-)) demonstrated responses to E. coli than free LPS. In conclusion, a proportion of macrophages obtained following migration out of the lamina propria of normal terminal ileal and colonic mucosal samples express CD14, TLR2 and TLR4. These cells respond to free LPS and E. coli, as demonstrated by the expression of TNF-alpha.
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PMID:Responses to free lipopolysaccharide and Escherichia coli by normal human intestinal macrophages, following their migration out of the lamina propria. 1596 53

As macrophages are often called to function at times of elevated ambient temperature (e.g., during local inflammation or systemic fever), it is possible that their production of critical effector molecules, such as nitric oxide (NO) or inducible NO synthase (iNOS), is sensitive to physiological changes in temperature. To test this possibility, the threshold requirements for production of NO and iNOS in murine peritoneal macrophages maintained under normothermic conditions (37 degrees C) or following mild (fever-range) hyperthermia (39.5 degrees C) were compared. We found that hyperthermia alone had no observable effect on basal NO production or iNOS protein or message. However, although interferon (IFN)-gamma and lipopolysaccharide (LPS) were needed to induce NO at 37 degrees C, we observed that addition of only LPS was sufficient for production of NO if there were a pretreatment at 39.5 degrees C. Further, if IFN-gamma and LPS were given after thermal exposure, a substantial increase in NO and iNOS was observed over that seen using cells kept at normothermic conditions. Macrophages isolated from mice lacking heat shock factor-1 did not attenuate the ability of mild thermal stress to modulate NO production. Reverse transcriptase-polymerase chain reaction data revealed that thermal regulation of iNOS expression is not entirely at the transcriptional level, suggesting possible points of post-transcriptional thermal sensitivity. These data support the concept that altering the thermal microenvironment is an important means by which the host can manipulate macrophage responses. Increases in temperature (e.g., during fever) may function to lower the activation threshold needed for production of effector molecules in times of infection.
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PMID:Nitric oxide production is regulated by fever-range thermal stimulation of murine macrophages. 1600 Mar 92

Factors such as genetic heterogeneity in the immune response contribute to respiratory syncytial virus (RSV) bronchiolitis severity. Such heterogeneity may manifest by an aberrant proliferation of phytohaemagglutinin (PHA)-stimulated peripheral blood mononuclear cells (PBMC) in response to lipopolysaccharide (LPS). The proliferation of PBMC was analysed in 52 infants: 21 ambulatory infants with mild RSV bronchiolitis (group I), 26 hospitalized infants with RSV bronchiolitis on ward (group II) and five intensive care unit (ICU) hospitalized infants (group III). Proliferation was analysed in response to negative control, PHA (LPS) and LPS/PHA. The TLR4 mutations were genotyped using reverse-transcriptase-polymerase chain reaction. The optical density (OD) post-LPS/PHA of group II (1.27 +/- 0.63) was significantly higher than group II (0.65 +/- 0.38, P = 0.005) or group I (0.63 +/- 0.33, P = 0.003), suggesting hyporesponsiveness to the LPS attenuation effect. None of the ICU hospitalized infants demonstrated OD readings post-LPS/PHA under the 0.75 threshold as opposed to group I (67% under 0.75) and group II (69%) (P < 0.05). The responses to negative-control, LPS and PHA stimulation alone were similar across groups. The presence of TLR4 mutations (Asp299Gly and Thr399Ile) were associated with severe RSV bronchiolitis and were significantly over-represented in groups II and III. These findings suggest that impairments of PBMC function manifested by hyporesponsiveness to LPS as well as the presence of TLR4 mutations are associated with an increased risk for more severe RSV bronchiolitis in previously healthy infants. A certain threshold of LPS hyporesponsiveness may have a very high negative predictive value for ICU hospitalization, even better than the determination of known TLR4 mutations for this purpose.
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PMID:Lipopolysaccharide hyporesponsiveness as a risk factor for intensive care unit hospitalization in infants with respiratory syncitial virus bronchiolitis. 1654 64

We investigated the effect of transforming growthfactor beta (TGFbeta1) short hairpin RNA (shRNA) mediated by pcDU6 plasmid on TGFbeta1 expression in human peritoneal mesothelial cells (HPMCs) and compared that effect with the effect of antisense TGFbeta1 RNA. We designed two pairs of oligonucleotides for two selectedfragments of coding sequence containing a 21-nucleotide (nt) TGFbeta1 sequence starting with GGCC. After annealing, double-stranded DNA was formed and separately ligated to plasmid pcDU6 [pcDNA3.1(-) with U6 promoter). The inverted motif contained six spacers and four Ts, which made it possible to form shRNA (TGFbgeta1 shRNA1 and TGFbeta1 shRNA2). We generated recombinant human TGFbeta1 antisense mammalian expression vector, and we isolated HPMCs from human greater omentum by pancreatin disaggregation to establish a stable cell-culture model. We used Lipofectamine 2000 to transfect third-passage HPMCs with plasmid pcDU6 mediating the expression of TGFbeta1 and plasmid pcDNA3.1(-) mediating the expression of antisense TGFbeta1 messenger RNA (mRNA). The resulting transfected cells were then stimulated with 4.25% D-glucose and 10 microg/mL lipopolysaccharide (GS+LPS). We used semi-quantitative reverse-transcriptase polymerase chain reaction to detect the expression of TGFbeta1, fibronectin (FN), collagen 1, and plasminogen activator inhibitor type 1 (PAI-1) mRNA by the stimulated cells. The TGFbeta1, FN, and PAI-1 protein levels in the culture supernatant were measured with a sandwich enzyme-linked immunosorbent assay. Expression of TGFbeta1 was significantly upregulated in HPMCs stimulated with GS+LPS (p < 0.01). As compared with control HPMCs in serum-free F12 medium, HPMCs transfected with TGFbeta1 antisense RNA showed inhibited expression of FN, collagen 1, and PAI-1 mRNA (17%, 26%, and 9.6% respectively after 24 hours). Forty-eight hours after transfection, the FN and PAI-I proteins were inhibited by 54.55% and 61.13% respectively (p < 0.05). In the pcDU6 plasmid vector-mediated TGFbeta1 shRNA groups, TGFbeta1 expression was obviously downregulated as compared with the GS+LPS group and the pcDU6 void vector group (p < 0.01). No significant difference was observed between the pcDU6 plasmid vector-mediated TGFbeta1 shRNA groups (p > 0.05). No significant difference was observed between the pcDNA3.1(-) vector-mediated antisense RNA group and the pcDU6 void vector group (p > 0.05). The expression of TGFbeta1 in pcDU6 plasmid vector-mediated TGFbeta1 shRNA groups was obviously downregulated as compared with the pcDNA3.1(-) plasmid vector-mediated antisense RNA group (p < 0.01). In HPMCs stimulated with GS+LPS, pcDU6 plasmid vector-mediated shRNA can significantly inhibit the induced expression of TGFbeta1. These results suggest the possible application of pcDU6 plasmid vector-mediated shRNA in preventing peritoneal fibrosis in patients receiving peritoneal dialysis.
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PMID:Inhibition of transforming growth factor beta (TGFbeta1) expression and extracellular matrix secretion in human peritoneal mesothelial cells by pcDU6 vector-mediated TGFbeta1 shRNA and by pcDNA3.1(-)-mediated antisense TGFbeta1 RNA. 1668 83

Adult mesenchymal stem cells (MSCs) are promising tools for such applications as tissue engineering and cellular therapy. It is not clear how stem cells exposed to unfavorable conditions (e.g., hypoxia or inflammation) respond to signals of danger after in vivo transplantation. Toll-like receptors (TLRs) play a major role in the immune system, participating in the initial recognition of microbial pathogens and pathogen-associated components. This study was designated to determine the role of TLRs in human MSCs. Reverse transcriptase-polymerase chain reaction (RT-PCR) and flow cytometry analysis demonstrated that MSCs derived from human adipose tissue and bone marrow express TLR-1, TLR-2, TLR-3, TLR-4, TLR-5, TLR-6, and TLR-9. We investigated induction of the differentiation and proliferation of human adipose tissue stromal cells (hADSCs) by TLR agonists, including flagellin, peptidoglycans (PGN), lipopolysaccharide (LPS), the synthetic double-stranded RNA analog poly(I:C), and synthetic CpG oligodeoxydinucleotide (CpG-ODN). None of these agonists, except ODN, affected the proliferation of hADSCs. LPS and PGN increased osteogenic differentiation, but CpG-ODN decreased it. Poly(I:C) itself did not affect adipogenic or osteogenic differentiations, but exerted a synergistic effect on LPS- or PGN-induced osteogenic differentiation. RT-PCR analysis demonstrated that LPS and PGN induce osteogenic markers in hADSCs. TLR agonists affected the expression of chemokines and cytokines differentially. Furthermore, hADSCs affected the expression of specific TLRs in vitro under hypoxic conditions. These data provide evidence of a nonimmune role for TLR signaling on MSCs and may provide clues to the behavior of transplanted MSCs in vivo.
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PMID:Role of toll-like receptors on human adipose-derived stromal cells. 1690 95

Hyungbangjihwangtang (HJT), a prescription of Sasang Constitutional Medicine, has been commonly used to treat diarrhea and edema of Soyangin in Korea. This study investigated the effect of HJT on lipopolysaccharide (LPS)-induced inflammatory cytokine production using peripheral blood mononuclear cells from the Soyangin. The inhibitory effect of HJT on LPS-induced inflammatory cytokine production was investigated using the enzyme-linked immunosorbent assay. Reverse transcriptase-polymerase chain reaction was used to investigate the interleukin (IL)-1beta mRNA expression. The expression level of nuclear factor (NF)-kappaB was examined by Western blot. HJT significantly inhibited the IL-1beta, IL-4, and tumor necrosis factor (TNF)-alpha production. The maximal inhibition rate of IL-1beta, IL-4, IL-6, IL-8, and TNF-alpha production by HJT was 240.0 +/- 48.8%, 78.4 +/- 24.7%, 27.6 +/- 10.6%, 20.7 +/- 59.8%, and 113.0 +/- 5.2%, respectively. HJT decreased the IL-1beta mRNA expression. HJT also inhibited the activation of NF-kappaB. These results suggest a potential role of HJT as a source of anti-inflammatory agent for inflammatory diseases.
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PMID:LPS-induced inflammatory cytokine production was inhibited by HyungbangJihwangTang through blockade of NF-kappaB in peripheral blood mononuclear cells. 1765 94


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