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)

PU.1 is a transcription factor found in macrophages, B cells, neutrophils, and hemopoietic stem cells. In macrophages PU.1 regulates a number of genes, including c-fms, CD11b, CD18, and FcgammaR1b. Previously, in primary macrophages PU.1 binding to the sequence GAGGAA was found to be induced by treatment with bacterial lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma). Here we investigated the role of protein kinase C (pKC) in the induction of PU.1 binding in macrophages. We report that pharmacological activation of pKC increases PU.1 binding, while inactivation of pKC inhibits the increases in PU.1 binding by agents which activate pKC in macrophages (LPS and tumor necrosis factor-alpha), but not by an agent which does not activate pKC (IFN-gamma). pKC activation may therefore be one pathway by which PU.1 binding may be increased in primary macrophages.
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PMID:Protein kinase C activation increases binding of transcription factor PU.1 in murine tissue macrophages. 992 Jul 60

The therapeutic effects of an intravenously injected carboxamide derivative (IS-741) on lung injury were studied in rats with cerulein-induced pancreatitis complicated by endotoxemia. Pancreatitis was induced by four intramuscular injections of cerulein (50 microg/kg at 1-hr intervals). Pancreatitis rats were injected intraperitoneally with 10 mg/kg of lipopolysaccharide (LPS) 6 hr following the first cerulein injection as a challenge of endotoxemia. Rats were divided into four groups: group I, pancreatitis with LPS; group II, pancreatitis with LPS treated with a continuous intravenous injection of IS-741 at 0.03 mg/kg/hr); group III, pancreatitis with LPS treated with a continuous intravenous injection of IS-741 at 0.3 mg/kg/hr); and group IV, pancreatitis with LPS treated with a continuous intravenous injection of IS-741 at 3 mg/kg/hr). IS-741 was administered 30 min before the endotoxemia challenge. Intense mononuclear cell infiltration and lung hemorrhage occurred in untreated pancreatitis rats with LPS (group I), but hemorrhage was not seen in group IV rats receiving a continuous injection of IS-741 shortly before the induction of endotoxemia. The IS-741-treated rats (groups II, III, and IV) had lower serum concentrations of cytokine-induced neutrophil chemoattractant (CINC), as well as fewer pulmonary infiltrates immunoreactive for CINC or Mac-1 (CD11b/CD18). The number of neutrophils infiltrating the lung in groups II, III, and IV was significantly lower than that of group I. Conversely, CINC production by bronchoalveolar macrophages in vitro were stimulated by LPS but were reduced by the presence of IS-741. The carboxamide derivative IS-741 effectively prevented pancreatitis-associated lung injury following the challenge of endotoxemia.
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PMID:Novel carboxamide derivative (IS-741) attenuates lung injury in rats with cerulein-induced pancreatitis complicated by endotoxemia. 1006 21

Cytokines play a pivotal role in the pathogenesis of septic shock. Proinflammatory cytokines such as tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) stimulate the progression of septic shock whereas the anti-inflammatory cytokine IL-10 has counterregulative potency. The amino acid glycine (GLY) has been shown to protect against endotoxin shock in the rat by inhibiting TNF-alpha production. In the current study we investigated the role of GLY on lipopolysaccharide (LPS) -induced cell surface marker expression, phagocytosis, and cytokine production on purified monocytes from healthy donors. GLY did not modulate the expression of HLA-DR and CD64 on monocytes, whereas CD11b/CD18 expression (P<0.05) and E. coli phagocytosis (P<0.05) decreased significantly. GLY decreased LPS-induced TNF-alpha production (P<0.01) and increased IL-10 expression of purified monocytes. Similarly, in a whole blood assay, GLY reduced TNF-alpha (P<0.0001) and IL-1beta (P<0.0001) synthesis and increased IL-10 expression (P<0.05) in a dose-dependent manner. The inhibitory effects of GLY were neutralized by strychnine, and the production of IL-10 and TNF-alpha was augmented by anti-IL-10 antibodies. Furthermore, GLY decreased the amount of IL-1beta and TNF-alpha-specific mRNA. Our data indicate that GLY has a potential to be used as an additional immunomodulatory tool in the early phase of sepsis and in different pathophysiological situations related to hypoxia and reperfusion.
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PMID:Immunomodulatory effects of glycine on LPS-treated monocytes: reduced TNF-alpha production and accelerated IL-10 expression. 1006 24

Polymorphonuclear neutrophil (PMNL) activation enhances microbial clearance but also contributes to the vascular damage and multiorgan failure associated with severe meningococcal sepsis. By use of a whole blood model of meningococcal bacteremia, loss of PMNL L-selectin and up-regulation of CD11b was observed in response to Neisseria meningitidis serogroups B and C, which is followed by opsonophagocytosis. PMNL priming with either Escherichia coli lipopolysaccharide (LPS) or FMLP prior to meningococcal challenge resulted in enhancement of both PMNL L-selectin shedding (1.5- to 4-fold) and phagocytosis (2- to 3-fold). Blockade of meningococcal LPS lipid A with recombinant bactericidal/permeability-increasing protein (rBPI21) resulted in partial inhibition of the PMNL activation and phagocytosis response to N. meningitidis. The effect of rBPI21 was reversed by excess E. coli LPS or FMLP. It is proposed that PMNL priming by N. meningitidis results in an exaggerated activation and phagocytosis response to the organism.
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PMID:Neutrophil response to Neisseria meningitidis: inhibition of adhesion molecule expression and phagocytosis by recombinant bactericidal/permeability-increasing protein (rBPI21). 1019 Dec 39

Multiple sclerosis (MS) is a central nervous disease thought to be elicited by an autoimmune process. Many studies in recent years have concentrated on finding the alterations in the peripheral blood immune profile in MS patients that would reflect disease activity. In the present study, we investigated surface antigen expression on lymphocytes and granulocytes from MS patients and control subjects. We have studied 29 patients suffering from relapsing-remitting or relapsing-progressive forms of MS. The disease was diagnosed in all patients at least 12 months before inclusion into the study. All patients had no attack at the study entry date or within a previous month. The control group included 29 age-matched subjects. Phenotyping of peripheral blood leukocytes was carried out with different fluorescence-conjugated murine monoclonal antibodies. The analysis was performed with three-color flow cytometry. The following antigens were determined [cluster of definition (CD)]: leukocyte common antigen (LCA) (B220, T 200, Ly-5), CD45; LPS-R (lipopolysaccharide receptor), CD14; found on all T cells, CD3; LFA-2 (lymphocyte function associated antigen, T 11), CD2; coreceptor for MHC class II molecules, found on helper T cells, CD4; coreceptor for MHC class I molecules, found on suppressor/cytotoxic T cells, CD8; B4, found on all human B cells, CD19; NCAM (neural cell adhesion molecule), CD56; integrin beta2 subunit, associated with CD11a (CD11a/CD18, LFA-1, alphaLbeta2) and CD11b (CD11b/CD18, Mac-1,CR3, alphaMbeta2), CD18; alphaL, alpha subunit of integrin LFA-1 (alphaLbeta2, CD11a/CD18), CD11a; alphaM, alpha subunit of integrin Mac-1 (CR3, alphaMbeta2, CD11b/CD18), CD11b; ICAM-1 (intercellular adhesion molecule), CD54; H-CAM, Hermes antigen, Pgp-1, CD44; AIM (activation inducer molecule), early activation antigen, CD69; T-cell receptor gammadelta, TCR gammadelta. In the MS group, we have found a significant increased expression of CD54 and CD44 antigens on lymphocytes, and higher percentage CD54(+) and CD11a+CD54(+) lymphocytes out of all lymphocytes compared with the control group. We have also found a significant increased expression of CD11a, CD18 and CD54 antigens on granulocytes, and higher percentage CD11b+CD18(+) granulocytes out of all granulocytes in MS patients compared with control. Higher levels of expression of the adhesion molecules may reflect the activation state of leukocytes in MS patients.
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PMID:Phenotyping analysis of peripheral blood leukocytes in patients with multiple sclerosis. 1021 Sep 17

We investigated the role of platelet-activating factor (PAF) as a priming signal for cytokine-induced neutrophil chemoattractant (CINC) expression by bronchoalveolar macrophages in acute pancreatitis. Pancreatitis was induced by four intramuscular injections of cerulein (50 micrograms/kg at 1-h intervals) in Wistar rats. The animals were injected intraperitoneally with 10 micrograms/kg of lipopolysaccharide (LPS) as a septic challenge. Pancreatitis rats were treated with a bolus intravenous injection of TCV-309 (3 or 30 micrograms/kg) 30 min before the septic challenge. Intense mononuclear cell infiltration and lung hemorrhage occurred in pancreatitis rats complicated with sepsis but were not seen in pancreatitis rats receiving a bolus TCV-309. Pancreatitis rats treated with TCV-309 had lower serum concentrations of CINC after septic challenge and lower levels of CINC messenger RNA (mRNA) in the lung, as well as fewer pulmonary infiltrates immunoreactive for CINC or Mac-1 (CD11b/CD18). In vitro CINC production in response to LPS by bronchoalveolar macrophages obtained from pancreatitis rats 6 h after the first cerulein injection, immediately before septic challenge, was enhanced but was significantly reduced in a TCV-309-sensitive manner. LPS-stimulated in vitro CINC production by naive bronchoalveolar macrophages was significantly enhanced by pretreatment with PAF. TMB-8 (an inhibitor of calcium release from endoplasmic reticulum) or W7 (calmodulin antagonist) completely abrogated the chemoattractant production by bronchoalveolar macrophages pretreated with PAF after LPS stimulation. Altered intracellular calcium, due to Ca2+ efflux from intracellular stores, may be involved in the "priming" of bronchoalveolar macrophages to release CINC after triggering with LPS during acute cerulein-induced pancreatitis. The PAF antagonist TCV-309 effectively prevented hyperactivity of bronchoalveolar macrophages and pancreatitis-associated lung injury after the septic challenge.
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PMID:Platelet-activating factor antagonist (TCV-309) attenuates the priming effects of bronchoalveolar macrophages in cerulein-induced pancreatitis rats. 1023 40

The Ob gene product, leptin, is an adipocyte-secreted hormone that centrally regulates weight control. However, leptin receptor is expressed not only in the central nervous system, but also in other systems such as reproductive and hematopoietic tissues. Human leptin has previously been shown to enhance cytokine production by murine peritoneal macrophages. In this paper we show that human leptin stimulates proliferation in a dose-dependent manner and functionally activates human circulating monocytes in vitro, by inducing the production of cytokines such as TNF-alpha and IL-6. Proliferation was assessed both by [3H]thymidine and bromodeoxyuridine incorporation at 48 h. We also checked the leptin stimulated monocyte expression of activation markers by flow cytometry: CD25, HLA-DR, CD38, CD71, CD11b, and CD11c expression increased after 72 h. Moreover, leptin increases the expression of the early activation marker CD69 in monocytes but not in lymphocytes. The stimulation produced by leptin is comparable to that produced by endotoxin [lipopolysaccharide (LPS)]. In addition, leptin can potentiate the stimulatory effect of LPS or PMA. Furthermore, we studied cytokine production (TNF-alpha and IL-6) simultaneously by flow cytometric detection of intracellular cytokines in the activated monocytes. Leptin produced a dose-dependent increase in the number of activated monocytes producing cytokines. These data indicate that leptin is a potent stimulatory hormone on human peripheral blood monocytes and suggest that it may have a role as a proinflammatory cytokine.
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PMID:Human leptin stimulates proliferation and activation of human circulating monocytes. 1035 75

Preterm infants have an increased incidence of infection, which is principally due to deficiencies in neonatal host defense mechanisms. Monocyte adherence is important in localizing cells at sites of infection and is associated with enhanced antimicrobial functions. We isolated cord blood monocytes from preterm and full-term infants to study their adhesion and immune functions, including superoxide (O2-) generation, degranulation, and cytokine secretion and their adhesion receptors. O2- production and degranulation were significantly diminished, by 28 and 37%, respectively, in adherent monocytes from preterm infants compared to full-term infants (P < 0. 05); however, these differences were not seen in freshly isolated cells. We also observed a significant decrease of 35% in tumor necrosis factor alpha secretion by lipopolysaccharide-stimulated adherent monocytes from preterm infants compared to full-term infants (P < 0.05); however, this difference was not observed in interleukin-1beta or interleukin-6 production by the monocytes. The cell surface expression of the CD11b/CD18 adhesion receptor subunits was significantly decreased (by 60 and 52%, respectively) in monocytes from preterm infants compared to full-term infants (P < 0. 01). The cascade of the immune response to infection involves monocyte upregulation and adherence via CD11b/CD18 receptors followed by cell activation and the release of cytokines and bactericidal products. We speculate that monocyte adherence factors may be important in the modulation of immune responses in preterm infants.
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PMID:Decreased superoxide production, degranulation, tumor necrosis factor alpha secretion, and CD11b/CD18 receptor expression by adherent monocytes from preterm infants. 1039 55

Neutrophil-mediated organ damage is a common feature of many disease states. We previously demonstrated that resuscitation with hypertonic salt solutions prevented the endotoxin-induced leukosequestration and consequent lung injury, and this effect was partially attributed to an altered surface expression of adhesion molecules, CD11b and L-selectin. In this study we investigated the mechanisms whereby osmotic stress evokes L-selectin shedding. The metalloprotease inhibitor RO 31-9790 prevented the osmotic down-regulation of L-selectin, indicating that this process was catalyzed by the same "sheddase" responsible for L-selectin cleavage induced by diverse inflammatory stimuli. The trigger for hypertonic shedding was cell shrinkage and not increased osmolarity, ionic strength, or intracellular pH. Volume reduction caused robust tyrosine phosphorylation and its inhibition by genistein and erbstatin abrogated shedding. Shrinkage stimulated tyrosine kinases Hck, Syk, and Pyk2, but prevention of their activation by the Src-family inhibitor PP1 failed to affect the L-selectin response. Hypertonicity elicited the Src family-independent activation of p38, and the inhibition of this kinase by SB203580 strongly reduced shedding. p38 was also essential for the N-formyl-methionyl-leucyl-phenylalanine- and lipopolysaccharide-induced shedding but not the phorbol ester-induced shedding. Thus, cell volume regulates L-selectin surface expression in a p38-mediated, metalloprotease-dependent manner. Moreover, p38 has a central role in shedding induced by many inflammatory mediators.
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PMID:Cell volume-dependent regulation of L-selectin shedding in neutrophils. A role for p38 mitogen-activated protein kinase. 1041 35

1. The potent coronary vasoconstrictor, endothelin-1 (ET-1) may also regulate neutrophil traffic into tissues. The aim of the present study was to characterize the endothelin receptors responsible and to investigate the underlying mechanisms. 2. ET-1 (1 nM - 1 microM) markedly enhanced attachment of human neutrophils to lipopolysaccharide-, and to a lesser extent, to ET-1-activated human coronary artery endothelial cells (HCAEC). This can partially be blocked by monoclonal antibodies against E-selectin, L-selectin or CD18, whereas combination of the three antibodies inhibited adhesion by approximately 83%. Increases in neutrophil adhesion evoked by ET-1 were also blocked by the platelet-activating factor (PAF) antagonists, BN 52021 (50 microM) and WEB 2086 (10 microM). 3. ET-1 downregulated the expression of L-selectin and upregulated expression of CD11b/CD18 and CD45 on the neutrophil surface and induced gelatinase release with EC50 values of approximately 2 nM. These actions of ET-1 were almost completely prevented by the ET(A) receptor antagonist FR 139317 (1 microM) and the ET(A)/ET(B) receptor antagonist bosentan (10 microM), whereas the ET(B) receptor antagonist BQ 788 (1 microM) had no effect. ET-1 slightly increased the expression of E-selectin and ICAM-1 on HCAEC, that was prevented by BQ 788, but not by FR 139317. 4. Receptor binding studies indicated the presence of ET(B) receptors (KD: 40 pM) on phosphoramidon-treated HCAEC and the predominant expression of ET(A) receptors (KD: 38 pM) on neutrophils. 5. These results indicate that promotion by ET-1 of neutrophil adhesion to HCAEC is predominantly mediated through activation of ET(A) receptors on neutrophils and subsequent generation of PAF.
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PMID:Endothelin-1 enhances neutrophil adhesion to human coronary artery endothelial cells: role of ET(A) receptors and platelet-activating factor. 1043 5


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