Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P43026 (lipopolysaccharide)
 62,215 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cultured bovine aortic endothelial cells (BAEs) synthesize and secrete type 1 plasminogen activator inhibitor (PAI-1), an Mr 50,000 glycoprotein which inhibits both urokinase and tissue-type plasminogen activators. The synthesis of PAI-1 in BAEs is positively regulated by a variety of agents. To elucidate the mechanisms which govern expression of the PAI-1 gene, total cytoplasmic RNA was prepared from BAEs and analyzed by Northern blotting using a 1.3-kilobase (kb) human PAI-1 cDNA probe. Hybridization under conditions of high stringency revealed two bovine PAI-1 RNA species, 3.0 and 1.6 kb in length. The ratio of the two species was approximately 4:1. The 3.0-kb mRNA was bound by oligo(dT)-cellulose, whereas the 1.6-kb form was not, suggesting that the latter form lacked a poly(A) terminus. Treatment of BAEs with transforming growth factor beta (TGF-beta), bacterial lipopolysaccharide (LPS), or tumor necrosis factor alpha (TNF-alpha) markedly enhanced the steady-state levels of both RNA species. In each case, increases were detectable within 1 h, and maximal effects (i.e. greater than 30-fold increase) were observed between 6 and 18 h of treatment, followed by a decline to near-basal levels by 48 h. The response to each of these agents was dose-dependent, with maximal induction observed at concentrations of 10 ng/ml TGF-beta, 10 ng/ml LPS, and 25 ng/ml TNF-alpha. Induction of PAI-1 mRNA by these agents was not blocked by the protein synthesis inhibitor cycloheximide, suggesting that de novo protein synthesis was not required. In fact, treatment with cycloheximide (2 micrograms/ml) alone also increased PAI-1 mRNA levels. Treatment with cycloheximide in combination with TGF-beta, LPS, or TNF-alpha further enhanced the accumulation of PAI-1 mRNA. Nuclear transcription run-on experiments indicated that these agents elevated the rate of PAI-1 gene transcription 20-30-fold and that gene template activity was temporally correlated with the accumulation of PAI-1 mRNA. These data are consistent with the conclusion that the observed increases in PAI-1 steady-state mRNA levels result from primary effects of these agents on the rate of PAI-1 gene transcription.
 ...
PMID:Regulation of type 1 plasminogen activator inhibitor gene expression in cultured bovine aortic endothelial cells. Induction by transforming growth factor-beta, lipopolysaccharide, and tumor necrosis factor-alpha. 249 79

We hypothesized that neutrophil adhesion and lung injury could occur independent of the surface receptor glycoprotein, Mo1 (C3bi receptor). We investigated whether preincubation of human neutrophil-derived cytoplasts (cell fragments that lack nuclei and granules and have a fixed number of surface Mo1 receptors) with plasma and lipopolysaccharide (LPS) would augment the cytoplasts' ability to cause lung injury when activated. We also investigated whether preincubating normal human neutrophils treated with anti-Mo1 antibody with plasma and LPS would increase the neutrophils' ability to adhere and cause lung injury. Human neutrophils infused into isolated salt-perfused rat lungs subsequently stimulated with phorbol 12-myristate 13-acetate (PMA) resulted in lung injury as assessed by the accumulation of 125I-bovine serum albumin in the lung parenchyma. The infusion of cytoplasts resulted in significantly less injury. Cytoplasts preincubated in 20% human plasma and LPS caused an increase in lung injury. Similarly, neutrophils treated with plasma, LPS, and anti-Mo1 antibody or neutrophils congenitally deficient in the Mo1 surface receptor and treated with plasma and LPS augmented lung injury. Plasma and LPS preincubation also increased anti-Mo1 antibody-treated neutrophil adhesion to endothelial cell monolayers after activation by PMA. Thus, plasma and LPS increase adhesion and lung injury caused by neutrophils or neutrophil fragments that share defects in Mo1 receptor expression.
 ...
PMID:Cytoplasts and Mo1-deficient neutrophils pretreated with plasma and LPS induce lung injury. 253 83

Leukocytes contain an enzyme that detoxifies bacterial lipopolysaccharides (also called endotoxins) by removing fatty acyl chains that are attached in acyloxy acyl linkage to the glucosamine backbone of lipid A. We describe the purification of an enzyme that carries out this activity, termed acyloxyacyl hydrolysis, from the HL-60 human promyelocyte cell line. The enzyme is a glycoprotein of apparent Mr = 52,000-60,000 that is found in low abundance (less than 0.001% of the cell lysate protein), principally in the granule fraction of the cells. The protein has two disulfide-linked subunits of apparent Mr = 50,000 and 14,000-20,000, each of which contains N-linked oligosaccharides. This is the first lipopolysaccharide-degrading enzyme that has been purified from animal cells.
 ...
PMID:Purification of acyloxyacyl hydrolase, a leukocyte enzyme that removes secondary acyl chains from bacterial lipopolysaccharides. 254 69

RU 41740 is a glycoprotein extract from Klebsiella pneumoniae described as a macromolecular aggregation of a lipopolysaccharide (LPS)-associated protein (F1 fraction) and a glycoproteic complex (P1 fraction). The human polymorphonuclear (PMN) response was studied after incubation of the cells in the presence of RU 41740, F1 and P1 fractions, or F1-P1 complex. Oxidative metabolism was assessed by chemiluminescence, O2 consumption, O2- generation, and degranulation by beta-glucuronidase release. Results were compared to data obtained with a homologous LPS. RU 41740, F1 fraction, and F1-P1 complex increased the respiratory burst of PMNs stimulated by opsonized zymosan (OZ). N-formylmethionylleucylphenylalanine (fMLP), phorbol myristate acetate, or the calcium ionophore A23187. The beta-glucuronidase release was stimulated by the same compounds when OZ or fMLP were used as stimuli. These effects were dose-dependent. In contrast, P1 fraction was inactive. Addition of polymyxin B resulted in a profound inhibition of both the F1 fraction and LPS activities but only in a partial inhibition of RU 41740 effects. These results strengthen the hypothesis that different biochemical pathways are involved in the enhancement of stimulated neutrophil functions by RU 41740.
 ...
PMID:Comparative effects of F1 and P1 fractions obtained from a Klebsiella pneumoniae glycoproteic extract (RU 41740) on polymorphonuclear leukocytes. 255 90

Adherence of circulating neutrophils to the microvascular endothelium is the initial step in diapedesis, the process by which leukocytes migrate through blood vessels to accumulate at sites of cutaneous disease or injury. The mechanisms underlying neutrophil-endothelial cell interactions are currently under intense investigation. It has now been clearly shown that human neutrophil adherence in vitro to cultured human endothelial cell monolayers can be enhanced by a variety of mediators of inflammation, that both the neutrophil and the endothelial cell may actively contribute to the adhesive interaction depending on the stimuli involved, and that the Mac-1, LFA-1, p150,95 glycoprotein family (CD11/CD18) plays a critical role. Chemotactic peptides (FMLP, C5a) and lipid mediators (LTB4, PAF) act primarily on the neutrophil to enhance its adherence to endothelium. The effect occurs quickly (maximal response within 2 min), can be rapidly modulated, and is dependent on the expression of CD11/CD18 on the neutrophil surface. In contrast, the cytokines, interleukin-1 (IL-1) and tumor necrosis factor (TNF), as well as bacterial lipopolysaccharide (LPS), induce cultured human endothelial cells to increase their adhesivity for human neutrophils by a process that is time-dependent, requiring 4 to 6 h for maximal response, and involves de novo RNA and protein synthesis. Two adhesion molecules are induced on the surface of endothelium in response to cytokine activation: endothelial-leukocyte adhesion molecule-1 (ELAM-1) and intercellular adhesion molecule-1 (ICAM-1). ICAM-1 is a ligand for LFA-1 (CD11a/CD18). Thus, CD11/CD18 plays a central role in neutrophil adherence to endothelium stimulated by chemotactic factors or cytokines. However, much still remains to be explored to further understanding of the fascinating but complex interaction of circulating neutrophils and the microvascular endothelium during acute inflammatory reactions in the skin.
 ...
PMID:Neutrophil-endothelial cell interactions: mechanisms of neutrophil adherence to vascular endothelium. 266 23

Serum amyloid A (SAA) gene expression and AA amyloid fibril formation were studied in A/J and SJL/J mice, two strains which have been reported to possess defects in AA fibril formation. Four types of inflammatory stimulation were employed: acute inflammation stimulated with lipopolysaccharide (LPS), chronic inflammation with casein in complete Freund's adjuvant, amyloidosis with injection of amyloid enhancing factor (AEF) together with casein in complete Freund's adjuvant, and non-amyloidogenic inflammation in the presence of AEF with injection of AEF together with LPS. Both A/J and SJL/J mice developed splenic amyloidosis 1 day after initiation of chronic inflammation in the presence of AEF. No amyloid deposits were detected during any of the other types of inflammation. Amyloidotic mice exhibited decreased amounts of SAA mRNA in liver and spleen concomitant with decreased amounts of SAA in serum. Alpha-I-acid glycoprotein mRNA was present in liver throughout the course of AEF accelerated amyloidosis, indicating that decreased SAA gene expression and AA fibril formation is not part of a general inhibitory effect of AEF on protein synthesis.
 ...
PMID:Serum amyloid A gene expression and AA amyloid formation in A/J and SJL/J mice. 276 89

Thy-1, a cell-surface glycoprotein of undetermined function, is expressed in relatively large amounts on mouse thymocytes, peripheral T cells, and neurons. It is widely used as a marker to distinguish peripheral T cells from B cells in mice. We show here that, in five distinct mouse strains, recombinant interleukin 4 (IL-4/B-cell stimulatory factor 1) strikingly induces membrane expression of Thy-1 on the vast majority of lipopolysaccharide (LPS)-stimulated normal murine B cells. Thy-1+ B cells are precursors for immunoglobulin-secreting cells. RNA blot analysis indicates that B cells express a Thy-1 mRNA of 1.8 kilobases, the same size as that found in T cells. Cell mixing experiments show that only cells derived from Thy-1.2+ donors express Thy-1.2, indicating that B cells expressing Thy-1 have not passively absorbed the glycoprotein from another cell source. Recombinant interferon-gamma inhibits Thy-1 induction by B cells stimulated with LPS and IL-4. Thy-1 is also induced on B cells that have been stimulated as a result of the specific activation of an IL-4-producing T-helper clone. Anti-IL-4 monoclonal antibody inhibits the induction of B-cell Thy-1 in this T-cell-B-cell interaction.
 ...
PMID:Interleukin 4 induces membrane Thy-1 expression on normal murine B cells. 290 Oct 96

We have used radioiodinated photoreactive bovine insulin as antigen to examine the molecular nature of immunogenic complexes that form on antigen-presenting cells. The probe was allowed to bind to either insulin-presenting B-hybridoma cells, lipopolysaccharide-stimulated blasts, or bovine insulin-specific helper-T-hybridoma cells in the dark. Samples were then exposed to light to induce crosslinkage, solubilized, and analyzed by gel electrophoresis. Two protein bands at about 36 kDa and 27 kDa were specifically labeled on antigen-presenting cells but not on helper T cells. Treatment of these bands with dithiothreitol or endo-beta-N-acetylglucosaminidase F showed that each is composed of a single glycoprotein. These proteins are immunoprecipitable with haplotype-specific but not control anti-Ia antibodies. This identifies the labeled bands as the alpha and beta subunits of class II major histocompatibility antigens. We conclude that a molecular complex may form between Ia and antigen on antigen-presenting cells and that formation of this complex does not require the presence of a helper-T-cell antigen receptor.
 ...
PMID:Photoaffinity labeling demonstrates binding between Ia molecules and nominal antigen on antigen-presenting cells. 294 39

The murine macrophage-like cell line J774.16 and peritoneal exudate cells elicited with thioglycollate or starch contain a major calmodulin (CaM)-binding protein (CaMBP) which is absent in trifluoperazine-resistant variants of J774, resident peritoneal macrophages and peritoneal macrophages elicited with concanavalin A, lipopolysaccharide, proteose peptone, or Bacillus Calmette-Guerin. Resident murine peritoneal cells maintained in tissue culture for 3 days begin to accumulate this protein, as do human peripheral blood monocytes after 7 days of culture. A specific competitive displacement radioimmunoassay was developed with the use of a rabbit antiserum raised to the partially purified CaM-binding protein and [125I]CaM covalently cross-linked to the principal CaM-binding protein in the preparation. The radioimmunoassay confirmed the unique cellular distribution of this protein, suggesting that it may be a marker for certain stages of macrophage differentiation. Monoclonal antibodies were prepared, and one of these was used to further purify the protein by immunoaffinity chromatography. A protein of Mr 50,000 to 60,000 was isolated. The protein could be selectively adsorbed to wheat germ agglutinin agarose and subsequently eluted with N-acetyl glucosamine. This property, plus the sensitivity of the protein to endoglycosidase F, led to the conclusion that it is a glycoprotein. The cellular distribution, subcellular localization, and evidence for glycosylation suggest that this protein may be a macrophage-specific receptor with a high affinity for Ca2+-CaM.
 ...
PMID:Purification and distribution of a novel macrophage-specific calmodulin-binding glycoprotein. 298 Oct 93

A monoclonal antibody (mAb) G-5-2 was isolated which binds to transformed as well as normal cells of the B lineage but not to cells of the T cell, myeloid lineages nor to fibroblasts. mAb G-5-2 reacts with pre-B and plasma cell-transformed lines, and it preferentially recognizes normal pre-B cells from fetal liver and bone marrow as well as plasma cells from spleen of mice. G-5-2+ fetal liver cells isolated by cell sorter express mRNA for mu heavy chain Ig gene and generate in vitro antibody-producing cells when co-cultured with lipopolysaccharide and rat thymocyte filler cells. During development the frequency and staining intensity of G-5-2+ cells in fetal liver from normal mice increases from 1% G-5-2+ cells at day 14 to approximately 7% positive cells at day 18 of gestation. Several strains or normal mice contain comparable numbers of G-5-2+ cells as well as B-220+ and BP-1+ B cell precursors in the fetal liver. Mice carrying the xid mutation have 3-4-fold less G-5-2+ as well as B-220+ and BP-1+ cells in the fetal liver, suggesting that the effects of the xid mutation may be manifested from early stages of B cell development. Fetal liver cells from mice carrying the scid mutation were found to contain normal numbers of G-5-2+ as well as B-220+ and BP-1+ pre-B cells. These results indicate that differentiation from progenitors to pre-B cells in scid mice may occur normally; the scid mutation would thus appear to affect the process of rearrangement and expression of the Ig genes in the developing pre-B cells. mAb G-5-2 precipitates a 76-kDa glycoprotein from surface-radiolabeled pre-B cells and plasma cells. Taken together, these results indicate that G-5-2 mAb recognizes a novel B cell lineage-specific surface molecule called PB76 which is preferentially expressed by pre-B cells and plasma cells.
 ...
PMID:PB76: a novel surface glycoprotein preferentially expressed on mouse pre-B cells and plasma cells detected by the monoclonal antibody G-5-2. 306 Mar 63


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>