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)

A monoclonal antibody (mAb), designated mNI-58A, was produced by immunizing mice with the lipopolysaccharide (LPS)-stimulated monocyte-like cell line, U937. The antigen defined by mNI-58A was widely expressed on various lymphoid cells and all cell lines examined except the erythroid cell line, K562. When the reactive patterns between mNI-58A and the mAbs to various human differentiation antigens (CD11a, CD11b, CD11c, CD14, CD16, CD18, CD23, CD28, CD29, CD31, CD43, CD44, CD45RA, CD50, CD54, CD58, CD80, CD102, CD106, HLA-class I and-class II antigen) were compared, that of mNI-58A was found to be similar to those of the leukocyte function-associated antigen-1 (LFA-1) mAbs. Using a competitive immunofluorescence binding assay it was found that the preincubation with one of the CD11a mAbs, 2F12 completely blocked the subsequent binding of mNI-58A. mNI-58A prevented the homotypic cell aggregation of the phorbol myristate acetate (PMA)-activated U937 cells (referred to as PMA-U937) and PMA-activated Epstein-Barr virus (EBV)-transformed B cell lines, B-85 and Mann. mNI-58A markedly induced the spread formation of the PMA-U937 cells following this blocking of the homotypic cell aggregation, whereas 2F12 did not under the same condition. The spread formation induced by mNI-58A was completely blocked by cytochalasin B (CyB), cytochalasin D (CyD), cycloheximide (CHX) or protein kinase C inhibitors, sphingosine and H-7. The U937 cells markedly adhered to the tumor necrosis factor-alpha (TNF-alpha)-stimulated human umbilical vein endothelial cells (HUVECs) and also to the extracellular matrix protein, fibronectin, but mNI-58A did not enhance or block these adhesion process. mNI-58A precipitated two glycoproteins with molecular weight 180 kDa and 95 kDa as determined by SDS-PAGE analysis, which were identical to the LFA-alpha (CD11a) and beta (CD18) chains of leukocyte integrin precipitated by the CD11a mAbs, respectively. Sequential immunoprecipitation studies using the CD11a mAb (2F12) also indicate that mNI-58A recognizes an epitope on the alpha-chain of the LFA-1 molecule. The ability of mNI-58A to block the PMA-U937 cells and to induce the spread formation of these cells suggests that mNI-58A is a novel mAb reacting with an epitope on the alpha-chain of LFA-1 different from those recognized with the existing CD11a mAbs.
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PMID:A novel monoclonal antibody mNI-58A against the alpha-chain of leukocyte function-associated antigen-1 (LFA-1) blocks the homotypic cell aggregation and actively regulates morphological changes in the phorbol myristate acetate (PMA)-activated human monocyte-like cell line, U937. 889 74

Collagen inhibits acute DNA strand breakage and apoptosis in sheep pulmonary artery endothelial cells (SPAEC) treated with lipopolysaccharide (LPS). Here we tested the ability of major basement membrane components, type IV collagen, laminin and fibronectin, and integrin ligands and anti-integrin antibodies to inhibit DNA breakage caused by LPS in SPAEC and BALB/c murine lung endothelial cells (MLEC). In situ labeling of DNA strand breaks with terminal deoxynucleotidyl transferase revealed similar DNA breakage in attached SPAEC and MLEC within 2 h after incubation with 1 microgram LPS/ml. Acute DNA strand breakage was reduced in cells plated on gelatin, type IV collagen, laminin, cellular fibronectin, or plasma fibronectin. DNA breakage was also suppressed by plating cells on surfaces coated with the integrin ligand hexapeptide, GRGDSP (40 micrograms/cm2), but not with GRADSP. LPS-induced DNA strand breakage was inhibited in MLEC plated on surfaces coated with antibodies to murine alpha 5-, beta 1, or beta 3-integrin subunits. Addition of anti-integrin antibodies, but not GRGDSP, to the medium above cell monolayers inhibited strand breakage. Despite similar acute DNA breakage, MLEC exhibited less detachment and apoptosis than SPAEC, consistent with a difference in the sensing or processing systems for apoptosis in these two cell types. These results demonstrate that extracellular matrices and integrin activation can inhibit the genotoxicity of LPS.
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PMID:Integrins inhibit LPS-induced DNA strand breakage in cultured lung endothelial cells. 892 30

The kinetics of IL-8, tumour necrosis factor-alpha (TNF-alpha) and IL-1 beta release by PMN adhered to fibronectin, laminin or plastic for 24 h in response to continuous stimulation with lipopolysaccharide (LPS; 50 ng/ml), N-formyl-Met-Leu-Phe (fMLP; 100 mM), or phorbol myristate acetate (PMA; 10 ng/ml), was investigated under altered oxygen tension conditions. Cell supernatants were sampled for cytokine content every 6 h and measured by ELISA. IL-8 was the most abundant cytokine, produced in a range of up to 5.4 ng/ml; TNF-alpha and IL-1 beta were produced in a range of up to 1 ng/ml. During normoxia, LPS was the most potent stimulus, inducing the release of each cytokine, while fMLP showed a less pronounced effect on IL-8 and IL-1 beta production and markedly inhibited TNF-alpha production. PMA markedly suppressed IL-8 and IL-1 beta release and failed to induce any release of TNF-alpha. Hypoxia had an overall inhibitory effect on cytokine release except for PMA-induced IL-1 beta release, and hypoxia/reoxygenation had a significant up-regulating effect except for a further inhibition of fMLP-induced release of TNF-alpha. Integrinmatrix protein ligation differentiated both spontaneous and externally induced cytokine release and its sensitivity to alteration in oxygen tension. Thus the process of PMN elaboration of inflammatory cytokines is controlled on multiple levels of signal transduction, differentiated by integrin-extracellular matrix interactions, and is sensitive to alterations in microenvironmental oxygen tension.
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PMID:Polymorphonuclear leucocyte (PMN)-derived inflammatory cytokines--regulation by oxygen tension and extracellular matrix. 897 28

Cell surface hydrophobicity of Campylobacter jejuni, C. coli, C. lari and C. upsaliensis was tested by hydrophobic interaction chromatography on octylsepharose CL-4B. The hydrophobicity was influenced by cultivation mode, presence or absence of intact lipopolysaccharide (LPS) and outer membrane protein structures. Species-specific differences of hydrophobic characteristics were not detected. Bacteria grown in fluid medium exhibited a high degree of hydrophobicity. Agar-grown bacteria showed hydrophobic interaction to a significant lower extent. By oxidation of LPS with sodium meta-periodate the hydrophobicity of agar-grown bacteria was slightly increased. Bacteria pretreated with proteinase K exhibited a marked decrease of hydrophobic interaction, whereas pretreatment with trypsin did not influence the hydrophobic interaction. Live bacteria were allowed to adhere to INT 407 cell membranes. With exception of one aflagellate strain, bacteria grown in fluid medium adhered better to the cellular substrate than agar-grown bacteria. This difference was not found when adhesion to fibronectin was tested. LPS-oxidized bacteria adhered significantly better to both cell membranes and fibronectin, whereas proteinase K treated bacteria exhibited a significant loss of adhesion capacity for both substrates.
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PMID:Hydrophobic characterization of thermophilic Campylobacter species and adhesion to INT 407 cell membranes and fibronectin. 907 18

We investigated the role of humoral factors in lipopolysaccharide (LPS) priming of polymorphonuclear leukocytes (PMN) using cells isolated from adults and from neonates. Plasma from newborn infants had decreased priming activity of adult plasma when mixed with LPS in studies measuring oxidative radical production of PMN after stimulation with a formyl bacterial oligopeptide (fMLP). This marked difference was not caused by LPS binding protein (LBP) because the LBP concentration in newborn and adult plasma were similar (138.4 +/- 12.9 U for adults, and 126.9 +/- 12.1 U for neonates, P = .53). Therefore, we attempted to identify other plasma factors that may contribute to LPS priming of PMN. We identified an LPS priming factor for PMN that is present in plasma, heat stable (56 degrees C for 30 minutes), enhanced by heparin, and concentrated in cold precipitates of plasma. Because these properties resemble those of plasma fibronectin, we assessed the role of fibronectin in LPS priming of PMN. Although fibronectin in phosphate-buffered saline (PBS) had little effect on LPS priming of PMN, fibronectin in combination with other plasma factors appeared to play a role in LPS priming of PMN because (1) removing fibronectin from adult plasma dramatically decreased LPS priming activity from plasma (P < .005), (2) addition of fibronectin to fibronectin-depleted plasma restored its LPS plasma priming activity (P < .05), and (3) neutralizing fibronectin with antibody decreased the LPS priming activity of plasma (60.3 +/- 1.3 v 30.2 +/- 2.2, P < .01). Thus, plasma fibronectin plays a role in LPS priming of PMN in the presence of other factors in plasma.
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PMID:Fibronectin enhances in vitro lipopolysaccharide priming of polymorphonuclear leukocytes. 916 62

To evaluate the biocompatibility of a newly developed degradable class of polyesterurethanes and their possible use as biomaterials, we investigated the cell and tissue interactions with these polymers using a small number of chemical base entities. The polymers were prepared by chain extension with diisocyanates of PHB/HV-diol and either PCL-diol or Diorez, another aliphatic polyester-diol. Regardless of the chemical composition of the four tested polyesterurethanes used as substrates, no morphological difference was observed either in the macrophages (macrophage cell line J774) or in the fibroblasts (fibroblast cell line 3T3) cultured on the polymers. In contrast, however, cell adhesion and growth of macrophages and fibroblasts were affected by the polymer properties. Compared to macrophages cultured on tissue culture polystyrene (TCPS), cells cultured on the test polymers exhibited levels of cell adhesion that varied from 65-100% of TCPS, and the doubling time was 25-43% higher on the polymers than on TCPS. Likewise, fibroblasts adhered to the polymers at lower rates (50-85% of TCPS) and grew at higher doubling times (125-140% of TCPS). Furthermore, cells cultured on the test polymers preserved their phenotypes: fibroblasts produced high amounts (up to 280% of control cells) of collagens Type I and Type IV and fibronectin; and macrophages produced nitric oxide (NO) and tumor necrosis factor alpha (TNF-alpha) in the same concentrations as control cells and responded to lipopolysaccharide treatment by the elevation of the production of NO and TNF-alpha, indicating that the cell-to-polymer interactions allow fibroblasts and macrophages to maintain their phenotypes. In vivo investigations showed that all four test polymers exhibit favorable tissue compatibility. The formed capsule was 60-250 microns thick. In addition, the polymers are degradable. After one year's subcutaneous implantation in rats, the molecular weight of the test polymers were reduced to about 50%, depending on the composition. Taken collectively, the present data demonstrate that the newly developed polyesterurethanes are cell and tissue compatible and biodegradable.
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PMID:Development of degradable polyesterurethanes for medical applications: in vitro and in vivo evaluations. 921 90

The S-layers of the Aeromonas spp. studied to date are composed of identical protein subunits which are translocated across the cytoplasmic membrane, periplasm and outer membrane to the cell surface, where they are assembled and tethered to the cell via an interaction with the O-polysaccharide side chains of the lipopolysaccharide. Aeromonas S-layers have the ability to bind a number of host factors such as fibronectin, laminin and vitronectin as well as providing resistance to serum killing and protease digestion. Aeromonas mutants unable to produce an S-layer are altered in their ability to cause disease. In the case of Aeromonas salmonicida, the loss of ability to produce an S-layer effectively abolishes virulence. However, in the case of A. hydrophila, the reduction in virulence caused by the loss of the S-layer is less significant.
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PMID:The synthesis, secretion and role in virulence of the paracrystalline surface protein layers of Aeromonas salmonicida and A. hydrophila. 929 15

Simple methods for obtention of primary cultures of isolated astrocytes and microglia from adult simian brain have been developed. Characterization of these two glial cell populations were performed by morphological observations and by immunocytochemistry. The astroglial cultures were obtained by an indirect method. After L-leucine methyl-ester treatment and trypsinizations, more than 99% of cells expressed glial fibrillary acidic protein (GFAP), whereas no macrophages or microglia could be detected. Likely, the 1% remaining cells were immature astrocytes or cells that lost their GFAP expression. Cultured simian astrocytes expressed vimentin, laminin, and fibronectin. We also found a constitutively low expression of major histocompatibility complex (MHC) class II by cultured astrocytes which was significantly enhanced by lipopolysaccharide (LPS), interferon gamma (IFN-gamma), or tumor necrosis factor alpha (TNF-alpha) treatments. Microglial cultures were obtained by a direct method of isolation using Percoll gradient separations and compared to simian monocyte-derived macrophages or alveolar macrophages. Microglial cells differed from macrophages by their proliferation upon granulocyte-macrophage colony stimulating factor (GM-CSF) treatment and by their typical morphology when observed by scanning electron microscopy. As macrophages, they expressed in vitro CD68, CD64, CD14, CD11b, MHC class II, and fibronectin. However, contrary to macrophages, simian cultured microglia expressed laminin. This observation suggests that microglia represent a new potential source of this extracellular matrix protein in the brain.
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PMID:Obtention and characterization of primary astrocyte and microglial cultures from adult monkey brains. 930 79

CGP 42112, a high-affinity ligand for angiotensin II AT2 receptors, binds to rat macrophage/microglia lacking AT2 receptors. Here we report that CGP-42112 binds to human monocytes and exerts specific effects. Binding studies revealed a single site, highly specific for CGP-42112, not displaceable by angiotensin II, angiotensin fragments, tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-4, IL-10, transforming growth factor-beta, or lipopolysaccharide (LPS). Incubation of purified human monocytes in serum-free medium with CGP-42112 enhanced, in a dose-dependent manner, cell attachment to fibronectin and collagen-coated dishes as well as matrix metalloproteinase-9 secretion. CGP-42112 did not promote cytokine secretion. In contrast, when added in the presence of low doses of LPS, CGP-42112 reduced the LPS-stimulated secretion of TNF-alpha, IL-1 alpha, IL-1 beta, and IL-6 without affecting IL-10 and decreased the LPS-stimulated matrix metalloproteinase-9 activity. Additionally, CGP-42112 inhibited the increase in protein kinase A activity produced by LPS. Our results indicate that CGP-42112 may modulate monocyte activation through binding to a novel receptor.
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PMID:CGP-42112 partially activates human monocytes and reduces their stimulation by lipopolysaccharides. 931 2

Glomerulosclerosis is the final outcome of a number of different causes of glomerular injury, during which the structures of the glomerulus are obliterated by extracellular matrix. Accumulating evidence suggests that infiltrating macrophages play a pivotal role in the progression to glomerulosclerosis. The present study defines the role played by macrophages at both cellular and molecular levels in the initiation of the sclerotic process in cultured rat mesangial cells. Macrophage-conditioned medium (MPCM) generated from thioglycollate-elicited, lipopolysaccharide-stimulated macrophages upregulated mesangial cell fibronectin production in a dose- and time-dependent manner, independently of cell proliferation. Immunoprecipitation of metabolically labeled 35S-fibronectin confirmed that the matrix protein was synthesized de novo. The genes for fibronectin and the matrix proteins laminin and collagen IV were also found to be upregulated 2.86 +/- 0.24-, 4.94 +/- 0.17-, and 3.03 +/- 0.31-fold over controls, respectively (P < 0.001). Macrophage modulation of matrix turnover was suggested by an upregulation of both transin and tissue inhibitor of metalloproteinase-1 gene transcription. Transforming growth factor (TGF) beta1, platelet-derived growth factor, tumor necrosis factor (TNF) alpha, or interleukin (IL)-1beta could not be detected in the MPCM per se; however, TGFbeta1 and platelet-derived growth factor AB were found to be secreted into mesangial cell culture supernatants. Secretion was augmented 1.69 +/- 0.16- and 2.28 +/- 0.28-fold, respectively (both P < 0.001), in response to MPCM. Northern blot analysis demonstrated that protein secretion had been preceded by upregulation of the genes for these cytokines (2.2 +/- 0.4-fold [P < 0.001] and 5.7 +/- 1.2-fold [P < 0.004], respectively). Incubation of MPCM with either neutralizing antibody or the growth factor receptor antagonist suramin demonstrated that TGFbeta1 played a significant, although minor, role in MPCM-stimulated fibronectin production. In conclusion, this study provides compelling evidence for a direct role of macrophages in the progression to glomerulosclerosis.
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PMID:Macrophages promote prosclerotic responses in cultured rat mesangial cells: a mechanism for the initiation of glomerulosclerosis. 933 80


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