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)

NF-kappaB/Rel transcription factors have been implicated in the differentiation of monocytes to either dendritic cells (DCs) or macrophages, as well as in the maturation of DCs from antigen-processing to antigen-presenting cells. Recent studies of the expression pattern of Rel proteins and their inhibitors (IkappaBs) suggest that their regulation during this differentiation process is transcriptional. To investigate differential gene expression between macrophages and DCs, we used commercially available gene microarrays (GEArray KIT), which included four of the NF-kappaB/Rel family genes (p50/p105, p52/p100, RelB, and c-rel) and 32 additional genes either in the NF-kappaB signal transduction pathway or under transcriptional control of NF-kappaB/Rel factors. To generate macrophages and DCs, human adherent peripheral blood monocytes were cultured with M-CSF or GM-CSF + IL-4 respectively for up to 8 days. DCs (and in some experiments, macrophages) were treated with lipopolysaccharide (LPS) for the last 48 h of culture to induce maturation. Cells were harvested after 7 days, cDNA was prepared and radiolabeled with alpha-(32)P-dCTP, then hybridized to gene arrays containing specific gene probes. beta-actin and GAPDH or PUC18 oligonucleotides served as positive or negative controls, respectively. The expression of all four NF-kappaB/Rel family genes examined was significantly upregulated in maturing DCs compared to macrophages. The strongest difference was observed for c-rel. RT-PCR determinations of c-rel, RelB, and p105 mRNAs confirmed these observations. Among the 32 NF-kappaB/Rel pathway genes, 14 were upregulated in mature DCs compared to macrophages. These genes were IkappaBalpha, IKK-beta, NIK, ICAM-1, P-selectin, E-selectin, TNF-alpha, TNFR2, TNFAIP3, IL-1alpha, IL-1R1, IL-1R2, IRAK, and TANK. By contrast, only mcp-1 (monocyte chemotactic protein 1) was upregulated in macrophages compared to DCs. NF-kappaB pathway genes upregulated in DCs compared to macrophages were constitutively expressed in monocytes then selectively downregulated during macrophage but not DC differentiation. LPS did not induce expression of most of these genes in macrophages but LPS did induce upregulation of IL-8 in mature macrophages. We conclude that NF-kappaB/Rel family genes, especially c-rel, are selectively expressed during differentiation of monocytes towards DCs. Moreover, this differential expression is associated both with activation of different NF-kappaB signal transduction pathways in DCs and macrophages and with expression of a unique subset of genes in DCs that are transcriptionally targeted by NF-kappaB/Rel factors. The results illustrate the ability of the NF-kappaB pathway to respond to differentiation stimuli by activating in a cell-specific manner unique signalling pathways and subsets of NF-kappaB target genes.
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PMID:Expression of different NF-kappaB pathway genes in dendritic cells (DCs) or macrophages assessed by gene expression profiling. 1157 45

Murine Nramp1 encodes a divalent cation transporter that is expressed in late endosomes/lysosomes of macrophages, and the transported cations facilitate intracellular pathogen growth control. The Nramp1 promoter is TATA box-deficient, has two initiator elements, and is repressed by c-Myc, in accordance with the notion that genes that deplete the iron content of the cell cytosol antagonize cell growth. Repression via c-Myc occurs at the initiator elements, whereas a c-Myc-interacting protein (Miz-1) stimulates transcription. Here we demonstrate that a non-canonical E box (CAACTG) inhibits basal promoter activity and activation by Miz-1. A consensus Sp1-binding site or GC box is also necessary for Miz-1-dependent transactivation, but not repression. Repression occurs by c-Myc competing with p300/CBP for binding Miz-1. Our results show that an Sp1 site mutant inhibits coactivation by p300 and that the murine Nramp1 promoter is preferentially expressed within macrophages (relative to a beta-actin control) compared with non-macrophage cells. The effect of the Sp1 site mutation on promoter function shows cell-type specificity: stimulation in COS-1 and inhibition in RAW264.7 cells. Miz-1-directed RNA interference confirms a stimulatory role for Miz-1 in Nramp1 promoter function. c-Myc, Miz-1, and Sp1 were identified as binding to the Nramp1 core promoter in control cells and following acute stimulation with interferon-gamma and lipopolysaccharide. These results provide a description of sites that modulate the activity of the initiator-binding protein Miz-1 and indicate a stimulatory role for GC box-binding factors in macrophages and a inhibitory role for E box elements in proliferating cells.
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PMID:Characterization of the murine Nramp1 promoter: requirements for transactivation by Miz-1. 1284 21

Such phagocytic leukocytes as macrophages and neutrophils are the key cellular components of innate immunity. The actin cytoskeleton is essential for their recruitment and activation in infected tissues. We have previously identified p65/L-plastin with Ca(2+)-, calmodulin-, and beta-actin-binding domains in macrophages. In order to further investigate the p65/L-plastin-involved cellular functions, we cloned the cDNA for murine grancalcin, a possible binding partner of p65/L-plastin. According to the sequence, grancalcin is a member of the penta-EF-hand protein family. We prepared recombinant (r) grancalcin for functional studies and found that it exhibited Ca(2+)-dependent precipitation. High-titer antibodies against the protein enabled us to detect intracellular grancalcin. A flow cytometric analysis revealed grancalcin to be highly expressed in macrophages and neutrophils. The protein was particularly abundant in those cells recovered from bacteria-infected sites. Immunohistochemical studies clarified that grancalcin was translocated to the actin cytoskeleton in macrophages upon exposure to bacterial lipopolysaccharide. These findings suggest that grancalcin plays a key role in leukocyte-specific functions that are responsible for host defense.
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PMID:Characterization of murine grancalcin specifically expressed in leukocytes and its possible role in host defense against bacterial infection. 1511 20

An exaggerated pro-inflammatory response in endotoxemia may lead to multiple organ damage including acute lung injury. Heat stress prior to endotoxemia results in attenuation of inflammation possibly by decreasing cytokine production. Monocyte chemoattractant protein (MCP)-1, a pro-inflammatory cytokine, is responsible for monocyte recruitment into the lung in acute lung injury. The objective of this study is to determine if pretreatment with heat results in decreased MCP-1 production in the lungs of endotoxemic rats at a transcriptional or post-transcriptional level. Rats were assigned to one of four groups: control, heat alone, heat with or without endotoxin. Rats were made endotoxemic by injection of Escherichia coli lipopolysaccharide. MCP-1 was measured in lavage fluid and MCP-1 mRNA in the lung tissue. Endotoxemia resulted in production of MCP-1. Control and heat alone rats had 21+/-4 vs. 20+/-3 pg/ml, p=0.75. MCP-1 concentration was decreased in the lavage fluid of pre-heated when compared to non-heated endotoxemic rats (37+/-28 vs. 70+/-35 pg/ml, p <0.02 ). However, the MCP-1 mRNA was higher in the heated compared to non-heated endotoxemic rats (1.59+/-0.35 vs. 0.74+/-0.51, MCP-1/beta-actin mRNA, p <0.01). Control and heat alone rats had undetectable mRNA MCP-1 in the lungs. Heat stress prior to endotoxemia results in decreased production of MCP-1 by a post-transcriptional mechanism.
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PMID:Heat stress decreases pulmonary MCP-1 production in endotoxemia. 1518 41

Visual and quantitative monitoring of cell-to-cell variation in the expression of manganese superoxide dismutase (MnSOD) mRNA by using novel ratiometric imaging with molecular beacons (MB) reveals a distinct change in patterns following induction of human breast-carcinoma cells with lipopolysaccharide. Interestingly, the pattern of cell-to-cell variation in a cell line stably transfected with a plasmid bearing a cDNA clone of MnSOD and overproducing the enzyme is significantly different from the pattern associated with MnSOD induction. The levels and the patterns of cell-population heterogeneity for beta-actin mRNA expression do not show distinct changes either following induction or in stably transfected cells. These results are significant in light of the reported relationship between this enzyme and malignant phenotype of breast-carcinoma cells. Use of MBs in ratiometric image analyses for cytoplasmic mRNAs represents a novel means of directly examining the stochasticity of transcription of MnSOD and other genes implicated in cellular phenotype regulation.
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PMID:Stochasticity of manganese superoxide dismutase mRNA expression in breast carcinoma cells by molecular beacon imaging. 1620 27

Decreased connexin 43 (Cx43) expression as a result of application of lipopolysaccharide (LPS) may limit the diffusion of intercellular signaling molecules that is essential to the coordinated function of neighboring cells. Therefore, it may be related to a ciliary beating defect in nasal epithelial cells and result in accumulation of harmful substances.Gap junction intercellular communication (GJIC) is altered during inflammation in tracheal epithelial cells. Thus, we aimed to investigate whether LPS affects the expression of Cx43, the elementary protein composing the gap junction of nasal epithelial cells, in vitro.LPS (Pseudomonas aeruginosa serotype 10) was applied to epithelial cells obtained from nasal polyp for 24 h in vitro. As an inflammatory indicator, IL-8 secretion was measured using a commercially available ELISA kit. Cx43 protein was detected semi-quantitatively using Western blotting. The nasal epithelial cells constitutively secreted IL-8 at a concentration of 0.45+/-0.03 ng/microg protein. In the presence of 10(-2) mg/ml LPS, the concentration of IL-8 was significantly increased to 0.55+/-0.05 ng/microg protein (n=8). Expression of the Cx43:beta-actin ratio decreased in a time- and dose-dependent fashion (10(-3)-10(-1) mg/ml LPS).
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PMID:Lipopolysaccharide decreases connexin 43 expression on nasal epithelial cells in vitro. 1629 92

Human monocyte leukemia cell line THP-1 was stimulated with lipopolysaccharide (LPS) to simulate the sepsis model and the expression of human glucocorticoid receptor-alpha (GR-alpha) mRNA in montocytes with endotoxin tolerance was investigated. THP-1 cells were cultured in serum-free medium, randomly divided into groups A, B, C, D and E, and stimulated with 0, 10, 10, 100, 0 ng/mL LPS for 24 h followed with 100, 100, 10, 100, 0 ng/mL LPS for another 24 h respectively. The expression of GR-alpha mRNA was detected by semi-quantitative reverse transcriptional polymerase chain reaction. Tumor necrosis factor-alpha (TNF-alpha) was determined by enzyme linked immunosorbent assay (ELISA). The results showed that the A values of GR-alpha/beta-actin in groups A, B, C, D and E was 0.607 +/- 0.006, 0.368 +/- 0.005, 0.484 +/- 0.008, 0.509 +/- 0.004 and 0.564 +/- 0.014 respectively with the difference being significant among the groups (P < 0.05). The GR-alpha mRNA expression was negatively correlated with the TNF-alpha expression (P < 0.01). It was concluded that the down-regulation of the expression of GR-alpha mRNA in endotoxin tolerance THP-1 cells might play an important role in the development of endotoxin tolerance in THP-1 cells.
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PMID:Correlation between endotoxin tolerance in human monocyte leukemia cell line THP-1 with glucocorticoid receptor-alpha. 1671 Oct

Two full-length cDNAs encoding glutathione S-transferase (GST) were cloned and sequenced from the hepatopancreas of planktivorous silver carp (Hypophthalmichthys molitrix) and bighead carp (Aristichthys nobilis). The silver carp and bighead carp GST cDNA were 920 and 978 bp in length, respectively, and both contained an open reading frame that encoding 223 amino acids. Partial GST cDNA sequences were also obtained from the liver of grass carp (Ctenopharyngodon idellus), crucian carp (Carassius auratu), mud carp (Cirrhinus molitorella), and tilapia (Oreochromis nilotica). All these GSTs could be classified as alpha-class GSTs on the basis of their amino acid sequence identity with other species. The three-dimensional structure of the silver carp GST was predicted using a computer program, and was found to fit the classical two-domain GST structure. Using the genome walker method, a 875-bp 5'-flanking region of the silver carp GST gene was obtained, and several lipopolysaccharide (LPS) response elements were identified in the promoter region of the phytoplanktivorous fish GST gene, indicating that the GST gene expression of this fish might be regulated by LPS, released from the toxic blue-green algae producing microcystins. To compare the constitutive expression level of the liver GST gene among the six freshwater fishes with completely different tolerance to microcystins, beta-actin was used as control and the ratio GST/beta-actin mRNA (%) was determined as 130.7 +/- 6.6 (grass carp), 103.1 +/- 8.9 (bighead carp), 92.6 +/- 15.0 (crucian carp), 72.3 +/- 7.8 (mud carp), 58.8 +/- 11.5 (silver carp), and 33.6 +/- 13.7 (tilapia). The constitutive expression level of the liver GST gene clearly shows that all the six freshwater fishes had a negative relationship with their tolerance to microcystins: high-resistant fishes (phytoplanktivorous silver carp and tilapia) had the lowest tolerance to microcystins and the high-sensitive fish (herbivorous grass carp) had the highest tolerance to microcystins. Taken together with the reciprocal relationship of constitutive and inducible liver GST expression level in some of the tested fish species to microcystin exposure, a molecular mechanism for different microcystin detoxification abilities of the warm freshwater fishes was discussed.
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PMID:Molecular cloning and characterization of alpha-class glutathione S-transferase gene from the liver of silver carp, bighead carp, and other major Chinese freshwater fishes. 1678 55

Recent advances in pharmacogenomics have suggested the association of clinical outcome of glucocorticoid-based anti-inflammatory therapy with a single nucleotide polymorphism at position 3435 in exon 26 (C3435T) of the MDR1 gene. In the present study, the effects of the MDR1 C3435T genotype on the time-dependent profiles of gene expression and function of MDR1/P-glycoprotein were evaluated in peripheral blood mononuclear cells (PBMCs) under lipopolysaccharide (LPS)-induced experimental acute inflammation. LPS treatment resulted in the rapid elevation of IL-1beta and TNF-alpha mRNA levels relative to beta-actin mRNA at 1 h, with a subsequent slight decrease at 3 h after the treatment, while the down-regulation of the relative concentration of MDR1 mRNA was found at 3 h, not at 1 h, after LPS treatment. Here, the C3435T genotype-dependent down-regulations of MDR1 mRNA level were found for CC(3435) and CT(3435), but not for TT(3435), and were 64.1+/-10.1%, 71.4+/-5.9% and 100.0+/-22.5% (+/-S.D.), respectively, of their respective baseline levels, which were independent of C3435T (0.010+/-0.005, 0.011+/-0.013 and 0.009+/-0.006 (+/-S.D.), respectively). The C3435T genotype-dependent down-regulation was supported by the increase of the intracellular accumulation of calcein in PBMCs treated with LPS for 72 h, and the increase was more predominant for CC(3435) than TT(3435). These data suggested that glucocorticoid-based anti-inflammatory therapy might be more effective for C(3435)-allele carriers than non-carriers.
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PMID:Genotype-dependent down-regulation of gene expression and function of MDR1 in human peripheral blood mononuclear cells under acute inflammation. 1685 22

Liver genes related to phase I and phase II detoxification, as well as inhibition of reactive oxygen species (ROS) production, were cloned, and their response to microcystin-LR (MC-LR) and lipopolysaccharide (LPS) exposure via intraperitoneal injection, was determined in a phytoplanktivorous fish, Nile tilapia (Oreochromis niloticus). The cloned full-length cDNA of tilapia soluble glutathione S-transferase (sGST) was classified as alpha-class GST based on their amino acid sequence identity with other species. The tilapia sGST clone was 861 bp in length, and contained a 25 bp 5'-UTR, a 167 bp 3'-UTR and an open reading frame of 669 bp, encoding a polypeptide of 222 amino acids. Using genome walker method, a 366 bp 5'-flanking sequence of tilapia sGST gene was further obtained, and the possible regulatory elements were identified. Partial cDNA sequences of glutathione peroxidase (GPX) and uncoupling protein 2 (UCP2) were also obtained by PCR using degenerate primers from tilapia liver. To study the transcriptional response of liver genes to microcystin treatment, tilapia were respectively exposed to a single 50 microg kg(-1) body weight (bwt) dose of pure MC-LR, a single 2 mg kg(-1) bwt dose of LPS and a co-exposure MC-LR and LPS (50 microg kg(-1) bwt+2 mg kg(-1) bwt), and were then sacrificed at 24 h post-exposure. Using beta-actin as external control, a significant increase (about 80%) in sGST mRNA expression was found in response to the MC-LR exposure after 24 h (P < 0.05), indicating the importance of sGST in microcystin detoxification. A slight decrease of sGST mRNA expression was observed in the liver of tilapia, exposed to LPS and MC-LR+LPS. It seems that the LPS response element (LPSRE), identified in the promoter region of tilapia sGST gene, may be functional at a rather low level. In contrast, the levels of cytochrome P450 1A (CYP1A) mRNA expression were found to keep unchanged to either MC-LR, or LPS, or MC-LR+LPS treatment, indicating that unlike the phase II enzyme (sGST), the phase I enzyme (CYP1A) might not play an important role in the detoxification process of microcystins. Although not significant, the mRNA expression level of GPX tended to increase in the liver of tilapia exposed to both MC-LR and LPS (P > 0.05). In addition, a significant increase in UCP2 mRNA expression was observed in the liver of tilapia exposed to LPS (P < 0.05), as well as an obvious but not significant increase in MC-LR exposure group. We suggest that phase II detoxification enzyme, instead of phase I detoxification enzyme, might be responsible for the strong tolerance of the phytoplanktivorous fish to microcystins, and hepatocyte proteins coping with oxidative stress (GPX and UCP2), might also have some auxiliary effect. In addition, the rather low and insignificant response of tilapia sGST gene to the inhibitory effect of LPS exposure, might possibly be critical to the phytoplanktivorous fish to utilize toxic blue-green algae.
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PMID:Structural and functional characterization of microcystin detoxification-related liver genes in a phytoplanktivorous fish, Nile tilapia (Oreochromis niloticus). 1704 49


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