Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0036690 (sepsis)
 59,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We tested the hypothesis that platelet-activating factor plays an important role in promoting endotoxin-induced lung injury by studying the effect of WEB 2086, a specific platelet-activating factor receptor antagonist, on lung vascular leak in endotoxin-treated rats. Intraperitoneal injection of Salmonella enteritidis endotoxin (2 mg/kg) increased the extravascular leakage of 125I-labeled albumin in perfused lungs at 30 min, 2 h, 6 h, and 48 h. Treatment with WEB 2086 (10 mg/kg ip) either 20 min before or 30 min after endotoxin injection significantly reduced lung injury at 2 h after endotoxin (leak index: control 0.74 +/- 0.03, endotoxin 1.79 +/- 0.14, endotoxin + pretreated WEB 1.23 +/- 0.09, endotoxin + posttreated WEB 1.21 +/- 0.13). In addition, posttreatment with WEB 2086 starting at 90 min after endotoxin injection markedly reduced lung leak at 6 h (control 0.74 +/- 0.03, endotoxin 1.29 +/- 0.14, endotoxin + WEB 0.71 +/- 0.06). The protective effect of WEB 2086 was not the result of cyclooxygenase blockade because the release of thromboxane B2 by endotoxin-treated lungs was not affected by WEB 2086. Furthermore, neither pretreatment nor posttreatment with WEB 2086 significantly reduced the endotoxin-induced increase in plasma glutathione disulfide, a marker of in vivo oxidative stress. In rats given a lethal dose of endotoxin (20 mg/kg ip), posttreatment with WEB 2086, starting at 2 h after endotoxin, significantly improved survival compared with vehicle treatment. We conclude that WEB 2086 ameliorated endotoxin-induced lung injury without reducing oxidative stress in the rat and suggest that blockade of platelet-activating factor receptor may be an important therapeutic consideration in sepsis-induced acute lung vascular injury.
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PMID:Beneficial effect of a platelet-activating factor antagonist, WEB 2086, on endotoxin-induced lung injury. 230 3

The transcription factor nuclear factor-kappaB (NF-kappaB) plays a key role in expression of many inflammatory genes responsible for the pathophysiology of sepsis-induced acute lung injury. We investigated whether the introduction of synthetic double-stranded oligodeoxynucleotides (ODNs) with consensus NF-kappaB sequence as transcription factor decoy can prevent acute lung injury with suppression of pulmonary expression of multiple genes involved in its pathological process in a cecal ligation and puncture septic mouse model. NF-kappaB decoy ODNs were introduced with the aid of the hemagglutinating virus of Japan-envelope vector method. Northern blot analysis indicated that transfection of NF-kappaB decoy ODN, but not of its scrambled form, resulted in a significant inhibition of sepsis-induced gene overexpression of inducible nitric-oxide synthase (iNOS), cyclooxygenase-2, histamine H(1)-receptor, platelet-activating factor receptor, and bradykinin B(1) and B(2) receptors in lung Histological damage in lungs tissues. (wall thickening, inflammatory infiltrate, and hemorrhage), increased pulmonary vascular permeability, and blood gas exchange impairment were clearly documented in mice after cecal ligation and puncture. These changes were strongly eliminated by the introduction of NF-kappaB decoy but not of scrambled ODN. The effects of the iNOS inhibitor FR260330 on these histological and functional derangements compared unfavorably with those of NF-kappaB decoy ODN transfection. Our results suggest that ODN decoy, acting as in vivo competitor for the transcription factor's ability to bind to cognate recognition sequence, may represent an effective strategy in the treatment of septic acute lung injury.
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PMID:Nuclear factor-kappaB decoy oligodeoxynucleotides prevent acute lung injury in mice with cecal ligation and puncture-induced sepsis. 1557 32

Newer immunosuppressive agents have dramatically reduced the rates of acute graft rejection over the last decade but may have exacerbated the problem of post-transplant infections. Causes of early mortality include graft dysfunction and sepsis. Late mortality occurs mainly due to sepsis. An excessive inflammatory response followed with a dramatic paralysis of cell-mediated immunity has been documented in septic patients. In transplanted individuals the pathophysiological changes of the immune response are further complicated by immunosuppressive agents. This article will focus on the effect of immunosuppressive agents and sepsis on cell-mediated immune responses. Moreover, potentially promising immunomodulatory approaches, i.e. human activated protein C, immunomodulatory diets containing L-arginine and fish oil, selective cytokine blockade, platelet-activating factor receptor antagonist, LPS receptor CD14 blockade and G-CSF, for the treatment of immunodysfunction in septic patients will be outlined in this review article. Most of them, however, have not been tested in the clinical arena in transplanted patients. Thus, the main part of the article, immunomodulation during sepsis in organ transplanted children is quite speculative and based on immunomodulatory strategies in other non-transplanted septic patients.
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PMID:Immunomodulation during sepsis in organ transplanted children. 1620 9

Sickle cell disease (SCD) is characterized by intravascular hemolysis and inflammation coupled to a 400-fold greater incidence of invasive pneumococcal infection resulting in fulminant, lethal pneumococcal sepsis. Mechanistically, invasive infection is facilitated by a proinflammatory state that enhances receptor-mediated endocytosis of pneumococci into epithelial and endothelial cells. As statins reduce chronic inflammation, in addition to their serum cholesterol-lowering effects, we hypothesized that statin therapy might improve the outcome of pneumococcal infection in SCD. In this study, we tested this hypothesis in an experimental SCD mouse model and found that statin therapy prolonged survival following pneumococcal challenge. The protective effect resulted in part from decreased platelet-activating factor receptor expression on endothelia and epithelia, which led to reduced bacterial invasion. An additional protective effect resulted from inhibition of host cell lysis by pneumococcal cholesterol-dependent cytotoxins (CDCs), including pneumolysin. We conclude therefore that statins may be of prophylactic benefit against invasive pneumococcal disease in patients with SCD and, more broadly, in settings of bacterial pathogenesis driven by receptor-mediated endocytosis and the CDC class of toxins produced by Gram-positive invasive bacteria.
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PMID:Statins protect against fulminant pneumococcal infection and cytolysin toxicity in a mouse model of sickle cell disease. 2009 77

Protease-activated receptors (PARs) belong to the family of G protein-coupled receptors. Among the four members, PAR1 plays a major role in orchestrating the interactions between coagulation and inflammation. PAR1 has opposing functions during sepsis, and PAR1 blockade or activation may be alternatively beneficial at early or late stages of different sepsis models. Studying molecular mechanisms of the crosstalk between inflammation and coagulation may lead to the identification of new targets for therapies in sepsis. However, the time-dependent switch of PAR1 from an exacerbating proinflammatory receptor to a protective anti-inflammatory receptor needs to be investigated before clinical trials can be recommended. Finally, as PAR1 seems to play a singular role in Streptococcus pneumoniae-induced sepsis through a crosstalk between PAR1 and platelet-activating factor receptor, the exact role of PAR1 needs to be investigated in other models of sepsis.
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PMID:Protease-activated receptor-1: key player in the sepsis coagulation-inflammation crosstalk. 2327 May 94

A crucial event in the initiation of many bacterial infections is the adherence of the bacteria to host cells, and bacterial surface structures and their interactions with host cell receptors play an important role in this process. Erysipelothrix rhusiopathiae is the causative agent of swine erysipelas, which may cause acute septicemia or chronic endocarditis and polyarthritis. To study the pathogenic mechanism of the widespread vascular disease observed in the acute form of swine erysipelas, we investigated the role of phosphorylcholine (PCho), a component of the E. rhusiopathiae capsule, in bacterial adherence to porcine endothelial cells (PECs) in vitro. We found that adherence of E. rhusiopathiae strain Fujisawa to PECs was twice that of adherence to control COS-7 cells and that the adherence rates of PCho-defective mutants were approximately 30-50% lower than those of the Fujisawa strain. The adherence of the Fujisawa strain to COS-7 cells transfected with the porcine platelet-activating factor receptor (PAFR) gene, which encodes a G protein-coupled receptor that has been shown to directly bind to Streptococcus pneumoniae via PCho in the bacterial cell wall, was not enhanced. Treatment with a PAFR antagonist (WEB-2086) did not inhibit bacterial adherence to PECs. Incubation of the bacterial cells with an antibody against PCho or SpaA, a choline-binding protein anchored to PCho of the Fujisawa strain, reduced the adherence of the strain to PECs. This effect was not observed when PCho-defective mutants were used. These results suggest that E. rhusiopathiae adheres to PECs via PCho and SpaA and that the PCho-mediated adherence is independent of PAFR.
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PMID:Phosphorylcholine and SpaA, a choline-binding protein, are involved in the adherence of Erysipelothrix rhusiopathiae to porcine endothelial cells, but this adherence is not mediated by the PAF receptor. 2485 34

Streptococcus pneumoniae is the leading cause of community-acquired pneumonia and sepsis, with adult hospitalization linked to approximately 19% incidence of an adverse cardiac event (e.g., heart failure, arrhythmia, infarction). Herein, we review the specific host-pathogen interactions that contribute to cardiac dysfunction during invasive pneumococcal disease: (1) cell wall-mediated inhibition of cardiomyocyte contractility; (2) the new observation that S. pneumoniae is capable of translocation into the myocardium and within the heart, forming discrete, nonpurulent, microscopic lesions that are filled with pneumococci; and (3) the bacterial virulence determinants, pneumolysin and hydrogen peroxide, that are most likely responsible for cardiomyocyte cell death. Pneumococcal invasion of heart tissue is dependent on the bacterial adhesin choline-binding protein A that binds to laminin receptor on vascular endothelial cells and binding of phosphorylcholine residues on pneumococcal cell wall to platelet-activating factor receptor. These are the same interactions responsible for pneumococcal translocation across the blood-brain barrier during the development of meningitis. We discuss these interactions and how their neutralization, either with antibody or therapeutic agents that modulate platelet-activating factor receptor expression, may confer protection against cardiac damage and meningitis. Considerable collagen deposition was observed in hearts of mice that had recovered from invasive pneumococcal disease. We discuss the possibility that cardiac scar formation after severe pneumococcal infection may explain why individuals who are hospitalized for pneumonia are at greater risk for sudden death up to 1 year after infection.
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PMID:Cardiotoxicity during invasive pneumococcal disease. 2562 43