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)

Six-week-old male Wistar rats were given a low fat diet containing 15% cod liver oil (FO; n = 30) or 15% safflower oil (SO; n = 30) for 6 weeks. In the polymorphonuclear leukocytes, arachidonic acid (AA) was significantly lower in the FO group than in the SO group (p < 0.001), and eicosapentaenoic acid (EPA) in the FO group was present in large amounts showing the EPA/AA ratio of 1.76. When lipopolysaccharide (LPS; 10mg/kg) was intraperitoneally injected, white blood cell counts in the blood significantly decreased in both groups (p < 0.001) compared to the controls 2 hours later, and at 4 hours, the counts in the SO group (2,033 +/- 151/mm3) were lower than in the FO group (3,189 +/- 624/mm3), (p < 0.01). In both groups, leukotriene B4 (LTB4) in the whole blood increased at 4 hours following LPS-administration compared to the controls (1,219 +/- 167.3pg/ml in the SO group and 600.0 +/- 109.0pg/ml in the FO group, p < 0.001). It should be noted that the level of LTB4 in the SO group was significantly higher than in the FO group (p < 0.001). Changes of the metabolites including decreased LTB4 production in the arachidonic cascade related to the increase of EPA may play a role in the inhibition of the decrease in white blood cell counts.
 ...
PMID:[Blood leukotriene B4 response to endotoxin in fish oil fed rats]. 133 37

Nitric oxide (NO), apart from its properties as a vasodilator, is a cytotoxic agent released from macrophages upon stimulation with immunomodulating agents such as interferon-gamma and endotoxin. In rat Kupffer cells endotoxin causes the release of NO as well as of tumor necrosis factor-alpha and prostaglandin E2 (PGE2). This eicosanoid and its second messenger, cyclic AMP, have been shown to increase nitric oxide formation in Kupffer cells treated with endotoxin (Gaillard et al. (1991) Pathobiology 59, 280-283). But not only added PGE2 but also the prostaglandin produced endogenously upon stimulation with endotoxin increases NO synthesis. Neither tumor necrosis factor-alpha nor interleukin-1 beta stimulate NO synthesis by themselves, but together with PGE2 they are as effective as lipopolysaccharide plus PGE2. To replace PGE2 in the combination with the cytokines, however, dibutyryl cAMP has to be present in higher concentrations than with LPS. Interleukin-6 alone or in combination with PGE2 or dibutyryl cAMP is without any effect. Anti-TNF-alpha as well as anti-PGE2 antibodies reduce the release of NO upon stimulation with LPS. Consequently, the effect of LPS on NO production seems to be in part due to the self-stimulating effect of PGE2 and some cytokines, both produced by Kupffer cells upon LPS stimulation.
 ...
PMID:Regulation by prostaglandin E2 of cytokine-elicited nitric oxide synthesis in rat liver macrophages. 133 72

The effect of interleukin-1 (IL-1) and bacterial endotoxin (lipopolysaccharide, LPS) on the activation of phosphoinositidase C (PIC) and on prostaglandin E2 release was studied in monocytes (M phi). Both IL-1 alpha and IL-1 beta increased the release of PGE2 in a concentration-dependent manner, with EC50s of 0.48 nM and 0.12 nM, respectively. Intact M phi were prelabelled with [3H]inositol and the formation of inositol phosphates (IPs) was estimated by ion exchange chromatography. PIC activity was estimated directly by measuring the conversion of [3H]phosphatidylinositol-4,5-bisphosphate to aqueous soluble radioactivity by M phi homogenates. IL-1 alpha (5.8 nM) increased the accumulation of IPs within 1-4 minutes and increases in IP3 and IP4 occurred before the increase in IP1+2 whereas LPS only increased the IPs level after at least 30 min. IL-1 alpha increased PIC activity in M phi homogenates within 15 min with an EC50 of 0.58 nM and IL-1 beta (0.1 nM) also increased activity. Neither IL-1 alpha nor IL-1 beta affected the PIC activity of membrane or cytosolic fractions. LPS decreased activity in all fractions. These data indicate that IL-1, but not LPS, can directly lead to an increased activity of PIC which may be involved in eicosanoid formation in M phi.
 ...
PMID:The role of inositol lipids in the activation of monocytes by interleukin-1 and bacterial endotoxin. 133 80

Both gram-negative infection and bacterial endotoxin (lipopolysaccharide, LPS) produce a marked neutropenia and increase glucose disposal by peripheral tissues. The purpose of the present study was to determine whether leukocyte depletion before these insults would diminish the commonly observed increases in tissue glucose uptake. Rats were depleted of circulating and marginated leukocytes with cyclophosphamide (CPA). Under basal postabsorptive conditions the subcutaneous injection of live Escherichia coli into control animals enhanced whole body glucose disposal that resulted in part from a stimulation of glucose uptake by the liver, spleen, intestine, and lung. These increases in tissue glucose uptake were not associated with an increase in neutrophil number, as assessed by myeloperoxidase (MPO) activity. CPA-induced leukopenia did not alter the sepsis-induced increase in glucose uptake by these tissues and whole body glucose use remained elevated. In contrast, skin and muscle proximal to the site of infection showed an increase in both glucose uptake and MPO activity. Furthermore, leukocyte depletion attenuated the elevated glucose uptake by skin and muscle near the inflammatory focus. The intravenous injection of LPS also increased whole body glucose disposal and enhanced glucose uptake by the lung, liver, spleen, intestine, and skin in saline-treated rats. Of these tissues the lung, liver, and spleen had a corresponding increase in neutrophil number. The LPS-induced increases in tissue glucose uptake in leukopenic rats were comparable, with the exception of liver and lung. In these tissues the incremental increase in glucose uptake after LPS was reduced 40-50% in leukopenic animals.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Sepsis- and endotoxin-induced increase in organ glucose uptake in leukocyte-depleted rats. 133 18

The relative avidity and titer of antibodies representing the 4 immunoglobulin G (IgG) subclasses (IgG1-4) reactive with Porphyromonas gingivalis, P. gingivalis-lipopolysaccharide (-LPS), streptokinase (SK) and tetanus toxoid (TT) in the sera of patients having adult periodontitis and of healthy controls were measured. Patient antibody titers to P. gingivalis and P. gingivalis-LPS were found to be significantly elevated for IgG, IgG1 (no P. gingivalis-LPS antibodies) and IgG2. The predominant antibody response to P. gingivalis and P. gingivalis-LPS occurred in the IgG2 subclass. When the relative avidity of the antibodies to P. gingivalis and P. gingivalis-LPS were examined, no significant differences between control and patient sera could be identified. However, anti-P. gingivalis and P. gingivalis-LPS antibodies were found to possess significantly lower relative avidity than either SK or TT antibodies. The IgG1 subclass antibodies to P. gingivalis, SK and TT all appeared to be of high relative avidity. In contrast, anti-P. gingivalis and P. gingivalis-LPS of the IgG2 subclass were of significantly lower relative avidity. Since the predominant humoral response to P. gingivalis occurs in the IgG2 subclass, the low relative avidity of these antibodies predominates in measurements of whole serum activity.
 ...
PMID:Avidity and titer of immunoglobulin G subclasses to Porphyromonas gingivalis in adult periodontitis patients. 133

The immune system and the hypothalamic-pituitary-adrenal (HPA) axis play important role in the overall inflammatory response. The mechanism through which lipopolysaccharide (LPS, endotoxin) stimulates the HPA axis is not well understood. In order to clarify the role of hypophysiotropic peptides of paraventricular origin in the effect of LPS on ACTH and corticosterone secretion, the effect of LPS was studied on rats with lesions of hypothalamic paraventricular nucleus (PVN). It was shown that 90 min after 2 mg/kg LPS i.p. the ACTH, but not the corticosterone response was effectively blunted in PVN-lesioned rats, as compared to sham operated animals. However, in PVN-lesioned rats 240 min after treatment with LPS a significantly higher plasma ACTH and corticosterone level was monitored. It is, therefore, suggested that in response to LPS activation of HPA both CRF(s)-dependent and CRF(s)-independent mechanisms are involved, even a direct effect of the adrenal cortex should be taken into account.
 ...
PMID:CRF-dependent and CRF-independent mechanisms involved in hypophysial-adrenal system activation by bacterial endotoxin. 134 88

The purpose of this investigation was to analyse the macrophage subpopulations involved in the uptake of endotoxin in the liver. The results show that in normal B10.D2 mice the liver macrophages constitute a heterogeneous population of cells which, depending on their state of differentiation, are distinguished by their differential distribution in the liver acinus and by their ability to phagocytose latex. Following the intravenous administration of endotoxin (lipopolysaccharide = LPS) from Salmonella abortus equi, endotoxin-carrying non-parenchymal cells of the liver (NPLC) were investigated immunohistochemically (in situ) and immunocytochemically (after isolation) between 1 h and 14 days after the injection. The endotoxin content of the blood and of isolated NPLC was also determined, using radioactivity labeled LPS. Following LPS injection, the total number of macrophages in the liver increased, reaching a maximum after 3 days. There was a striking increase in the ratio of mature to immature macrophages. After day 3, the number of macrophages decreased again, returning to the pre-injection values by day 14. 1 h after the administration of LPS, 41% of the isolated NPLC were already endotoxin-positive, a percentage which remained constant until the 3rd day. Thereafter, the number of LPS-bearing cells increased to a maximum of about 52% on the 5th day. This increase mostly involved macrophages which had taken up endotoxin. Concurrent with these changes there was a threefold increase in radioactivity-labeled LPS from the 7th h to the 5th day after injection.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:The role of macrophages in the uptake of endotoxin by the mouse liver. 134 96

The effect of conditioned medium on the biosynthesis and glycosylation profile of acute phase proteins secreted by the human hepatoma cell line Hep G2 was studied. Conditioned medium was prepared from nonactivated [CM-LPS(-)] and ex vivo lipopolysaccharide activated [CM-LPS(+)] monocytes from eight patients with active rheumatoid arthritis (RA), five patients with active systemic lupus erythematosus (SLE), and seven healthy subjects. The biosynthesis of albumin, alpha 1-antichymotrypsin and alpha 1-proteinase inhibitor and the profile of glycosylation of proteinase inhibitor were analysed. CM-LPS(-) from patients with SLE had a similar effect to CM-LPS(-) from healthy subjects. In contrast, CM-LPS(-) from patients with RA had the same effect as CM-LPS(+) from healthy donors. A similar effect to that of CM-LPS(+) of healthy subjects was seen with CM-LPS(+) from patients with SLE and with CM-LPS(+) from patients with RA. The treatment of CM-LPS(+) with antibodies against interleukin 6 neutralised most of its ability to induce changes in the biosynthesis and glycosylation of acute phase proteins. Antibodies to interleukin 1 and tumour necrosis factor alpha had only a limited effect on the ability of CM-LPS(+) to induce changes of albumin and alpha 1-antichymotrypsin syntheses, whereas they had no effect on the biosynthesis and glycosylation of proteinase inhibitor. These results indicate that: (a) monocytes isolated from patients with active SLE and active RA have different capabilities of inducing alterations of acute phase proteins in vitro; (b) ex vivo activation of monocytes from patients with SLE leads to the full induction of its capabilities to change acute phase proteins, whereas the activation of monocytes from patients with RA has no additive effects; and (c) interleukin 6 seems to be a major cytokine involved in the regulation of the glycosylation pattern of acute phase proteins.
 ...
PMID:Different capabilities of monocytes from patients with systemic lupus erythematosus and rheumatoid arthritis to induce glycosylation alterations of acute phase proteins in vitro. 137 63

Previous research in this laboratory, using photoactivatable radioiodinated lipopolysaccharide derivatized with sulfosuccinimidyl-2-(p-azidosalicylamide)-1,3'-dithiopropionate (125I-ASD-LPS), has resulted in the identification of a specific LPS receptor with a molecular mass of approximately 73 kDa on murine lymphocytes and splenic macrophages. The experiments presented in this report investigated whether a similar LPS-binding protein was also expressed on human peripheral blood populations, including monocytes, lymphocytes, neutrophils, platelets, and erythrocytes. Each cell population was incubated with 125I-ASD-LPS, UV irradiated, washed, reduced, and solubilized, and the cell lysates were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by autoradiography. On all of the cell populations, except erythrocytes, a similar 73-kDa LPS-binding protein was present. In addition, each population also expressed lower-molecular-weight secondary LPS-binding proteins, some of which were conserved among the populations. Binding of the photoactivatable LPS probe was found to be both time and temperature dependent. These data support the concept that the 73-kDa LPS-binding protein is conserved on multiple cell types from a variety of species.
 ...
PMID:Identification and characterization of lipopolysaccharide-binding proteins on human peripheral blood cell populations. 137 70

The ability of Bdellovibrio bacteriovorus to relocalize the OmpF major outer membrane porins from its Escherichia coli prey to its own outer membranes is diminished in prey expressing smooth lipopolysaccharide (S-LPS). Since porins exist in the membrane complexed with LPS, we examined the LPS associated with relocalized porin to determine whether it had been acquired intact, mixed or replaced with Bdellovibrio LPS, or derivatized by the bdellovibrios. The relocalized trimers were found associated with the same LPS originally bound to them in the E. coli. The bulk-phase LPS from bdellovibrios grown on various chemotypes of rough prey was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to determine whether more than the trimer-bound LPS was acquired by the bdellovibrios. This analysis revealed bands of Bdellovibrio LPS matching the LPS chemotype of the prey. One or two other bands were identical in migration to the LPS of prey-independent mutants of B. bacteriovorus and represented bdellovibrio-synthesized LPS. The LPS of bdellovibrios grown on prey with radiolabeled lipid A showed radioactivity only in gel band positions identical with those of the prey's LPS. The amount of this prey-derived LPS was shown by enzyme-linked immunosorbent assay to reach a constant value during the purification of the bdellovibrios, and it represented approximately 25% of the total Bdellovibrio LPS. Immunoelectron microscopy confirmed the presence of prey-derived LPS on the cell surface of bdellovibrios, and no evidence could be found for bdellovibrio-induced modifications of the relocalized prey LPS.
 ...
PMID:Acquisition of apparently intact and unmodified lipopolysaccharides from Escherichia coli by Bdellovibrio bacteriovorus. 137 16


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