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)

Plasma levels of antithrombin III, alpha 2-macroglobulin and inter-alpha-trypsin inhibitor, as well as those of various clotting, complement and other plasma factors, were significantly decreased in 18 patients suffering from hyperdynamic septic shock. A similar statistically significant reduction of the concentrations of several plasma factors (prothrombin and antithrombin III, plasminogen and alpha 2-plasmin inhibitor, complement factor C3 and clotting factor XIII) was observed in experimental endotoxaemia. In this model the reduction in the plasma levels of these factors was considerably diminished by the intravenous injection of a granulocytic elastase--cathepsin G inhibitor of lower molecular weight from soybeans. The results of both studies indicate that consumption of plasma factors in the course of Gram-negative sepsis proceeds not only via the classical routes (by activation of the clotting, fibrinolytic and complement cascades by system-specific proteinases such as thrombokinase or the plasminogen activator) but also to an appreciable degree of unspecific degradation of plasma factors by neutral proteinases such as elastase and cathepsin G. The endotoxin-induced release of both sorts of proteinases, the system-specific ones and the unspecific lysosomal proteinases from leucocytes and other cells, is likely to be mainly responsible for the consumption of antithrombin III and alpha-2-macroglobulin via complex formation (followed by elimination of the complexes) and the increased turnover of the inter-alpha-trypsin inhibitor as observed in the clinical study. The therapeutic use of an exogenous elastase--cathepsin G inhibitor in the experimental model was stimulated by the observation that human mucous secretions contain and acid-stable inhibitor of the neutral granulocytic proteinases, called HUSI-I or antileucoproteinase. This inhibitor protects mucous membranes and soluble proteins against proteolytic attack by leucocytic proteinases released in the course of a local inflammatory response. Preliminary results indicate that HUSI-I, which is produced by the epithelial cells of mucous membranes, does not belong to any known structural type of acid-stable proteinase inhibitor. The search for other candidates suitable for medication in humans led to the discovery of a potent elastase--cathepsin G inhibitor, called eglin, in the leech Hirudo medicinalis. This acid-stable inhibitor with a molecular weight close to 8100 has an unusual structural property in that the structure of the molecule is not stabilized by any disulphide bridge.
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PMID:Proteinase inhibitors in severe inflammatory processes (septic shock and experimental endotoxaemia): biochemical, pathophysiological and therapeutic aspects. 39 95

Leukocyte activation is a property of systemic infection. Animal experiments indicate interleukin-1 (IL-1) as a possible modulator, while contradictory results have been reported from in-vitro stimulation of isolated leukocytes. The purpose of the present study was to investigate the activation of isolated polymorphonuclear (PMN) leukocytes in vitro by preparations of recombinant human IL-1 beta and IL-1 receptor antagonist, which in earlier studies could elicit and abrogate, respectively, a sepsis-like syndrome in rabbits. They have also been shown to influence acute phase protein synthesis in mice and rats, and release of leukocyte cathepsin G in vivo. It was found that recombinant human IL-1 beta elicited a dose-dependent luminol-enhanced chemiluminescence response in isolated human PMN leukocytes in the dose range 8.8 x 10(-11)-8.8 x 10(-8) M. The effect could be blocked by prior treatment with the IL-1 receptor antagonist, indicating a direct effect on the specific IL-1 receptor. Preincubation by IL-1 beta enhanced the effect of a secondary challenge with phorbol 12-myristate 13-acetate or formyl-Met-Leu-Phe by 30-40%. The priming effect of rhIL-1 beta could also be blocked by the specific receptor antagonist. In this study, incubation of PMN leukocytes with rhIL-1 beta failed to induce degranulation of both azurophil (neutrophil proteinase 4/proteinase 3) and specific (lactoferrin) granules. rhIL-1 beta has been shown to induce degranulation in vivo, which is thus indicated as an indirect effect. We conclude that IL-1 beta is a direct and specific, but probably weak stimulator of the PMN leukocyte.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Stimulation of human polymorphonuclear leukocytes by recombinant human interleukin-1 beta. 162 64

Infusion of 3 X 10(10) live E. coli cells into anesthetized piglets induced severe septicemia with characteristic alterations in systemic and pulmonary circulation, lung function and morphology, blood cell counts and plasma protein composition. The simultaneous infusion of the elastase-cathepsin G inhibitor, r-eglin c, in a doses of 3.85 mg/kg X h for 4 hrs, reduced mortality, plasma protein consumption, and accumulation of interstitial fluid in the lungs. These findings are in favour of the concept that during septicemia the balance between liberated lysosomal proteinases and their extracellular inhibitors is severely disturbed. It can be at least partially restored by administration of an exogenous elastase inhibitor.
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PMID:Influence of the lysosomal elastase inhibitor eglin on the development of interstitial lung edema in E. coli bacteremia in pigs. 244 2

Degradation of structural elements and excessive consumption of humoral factors, especially of plasma proteinase inhibitors, by proteolysis and/or oxidation is a major cause of multiple organ failure in sepsis or septic shock. Such pathobiochemical reactions seem to be induced primarily by extracellularly liberated lysosomal proteins from PMN granulocytes (e.g. elastase, cathepsin G, myeloperoxidase, lactoferrin) as well as oxygen radicals produced during extensive phagocytosis. In clinical studies on septicemia and septic shock the consumption of plasma proteins including proteinase inhibitors was inversely correlated to the liberation of lysosomal factors, especially the granulocytic elastase. Administration of relatively specific elastase-cathepsin G-inhibitors (Bowman-Birk inhibitor, eglin) in experimental septicemia proved to be a promising therapeutic approach to reduce consumption of plasma proteinase inhibitors and development of interstitial lung edema in severe inflammation.
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PMID:Pathobiochemistry of sepsis: role of proteinases, proteinase inhibitors and oxidizing agents. 352 75

Alpha-2-macroglobulin (alpha 2M) may function as a proteinase inhibitor in vivo. Levels of this protein are decreased in sepsis, but the reason these levels are low is unknown. Therefore, we analyzed the behavior of alpha 2M in a baboon model for sepsis. Upon challenge with a lethal (4 baboons) or a sublethal (10 baboons) dose of Escherichia coli, levels of inactivated alpha 2M (i alpha 2M) steadily increased, the changes being more pronounced in the animals that received the lethal dose. The rise in i alpha 2M significantly correlated with the increase of thrombin-antithrombin III, plasmin-alpha 2-antiplasmin, and, to a lesser extent, with that of elastase-alpha 1-antitrypsin complexes, raising the question of involvement of fibrinolytic, clotting, and neutrophilic proteinases in the inactivation of alpha 2M. Experiments with chromogenic substrates confirmed that thrombin, plasmin, elastase, and cathepsin G indeed had formed complexes with alpha 2M. Changes in alpha 2M similar to those observed in the animals that received E. coli occurred in baboons challenged with Staphylococcus aureus, indicating that alpha 2M formed complexes with the proteinases just mentioned in gram-positive sepsis as well. We conclude that alpha 2M in this baboon model for sepsis is inactivated by formation of complexes with proteinases, derived from activated neutrophils and from fibrinolytic and coagulation cascades. We suggest that similar mechanisms may account for the decreased alpha 2M levels in clinical sepsis.
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PMID:Alpha-2-macroglobulin functions as an inhibitor of fibrinolytic, clotting, and neutrophilic proteinases in sepsis: studies using a baboon model. 769 93

The effect of supernatant from phorbol myristate acetate (PMA) stimulated human polymorphonuclear granulocytes (PMN) on human factor VII was studied in vitro. The supernatant caused a rapid loss in factor VII coagulant activity by the action of human leukocyte elastase (HLE) and cathepsin G in the supernatant, as demonstrated by the use of specific inhibitors of the two serine proteases, respectively. Preincubation of the supernatant with the elastase inhibitor and the cathepsin G inhibitor preserved 80% and 25% of the clotting activity, respectively. Calcium protected factor VII completely from the supernatant mediated inactivation. Cathepsin G and HLE purified from PMN each destroyed the coagulant activity of factor VII when added to a non-plasma system. There were, however, no effect on factor VII activity when cathepsin G was added to plasma. Polyacrylamide gel electrophoresis in the presence of SDS indicated that HLE and cathepsin G cleaved the zymogen in the same manner, producing (a) peptide(s) of low molecular mass and a single large product of 48 kDa. Preincubation of factor VII with calcium ions inhibited the proteolytic action of HLE and cathepsin G. It is suggested that HLE and cathepsin G from activated granulocytes may be partly responsible for the loss in factor VII activity that is observed during sepsis.
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PMID:Human leukocyte elastase and cathepsin G inactivate factor VII by limited proteolysis. 805 78

Upon stimulation, polymorphonuclear leucocytes (PMNs) release potent serine proteases, i.e. elastase, cathepsin G and proteinase 3, which contribute to the degradation of tissue and plasma components. Here, we describe the development of a plasma test to assess PMN-mediated fibrinogenolysis as a biochemical marker for actual PMN-derived proteolysis in vivo, useful for monitoring therapeutic efficacy, i.e. of elastase inhibitors. We generated a monoclonal antibody (MAb), designated 1-1/B3, with a high affinity for elastase-degraded fibrinogen (EDF). The epitope for 1-1/B3 becomes exposed in a time-dependent manner during digestion of fibrinogen with purified PMN-derived serine proteases and with isolated PMNs in vitro. However, 1-1/B3 does not react with plasma fibrinogen or with fibrin(ogen) degradation products generated by plasmin or by other active proteases that may occur locally, i.e. metalloproteases and lysosomal cathepsins. On the basis of MAb 1-1/B3, we developed a plasma test for the assessment of PMN-mediated fibrin(ogen) degradation products (PMN-FDP). In a panel of control plasmas, we observed concentrations of PMN-FDP of 8.2 +/- 0.9 ng mL-1 (n = 18). These values were increased twofold in patients with alpha 1-proteinase inhibitor deficiency (18.6 +/- 3.3 ng mL-1; n = 12; P < 0.0001) and even more in patients with sepsis (365.7 +/- 97.7 ng mL-1; n = 16; P < 0.0001). Furthermore, synovial tissue extracts from patients with rheumatoid arthritis contained increased levels of PMN-FDP, compared with synovial tissue extracts (P < 0.005) from patients with osteoarthritis.
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PMID:An enzyme immunoassay for polymorphonuclear leucocyte-mediated fibrinogenolysis. 906 9

Burkholderia cepacia is an opportunistic pathogen that has become a major threat to individuals with cystic fibrosis (CF). In approximately 20% of patients, pulmonary colonization with B. cepacia leads to cepacia syndrome, a fatal fulminating pneumonia sometimes associated with septicemia. It has been reported that culture filtrates of clinically derived strains of B. cepacia are hemolytic. In this study, we have characterized a factor which contributes to this hemolytic activity and is secreted from B. cepacia J2315, a representative of the virulent and highly transmissible strain belonging to the recently described genomovar III grouping. Biochemical data from the described purification method for this hemolysin allows us to hypothesize that the toxin is a lipopeptide. As demonstrated for other lipopeptide toxins, the hemolysin from B. cepacia was surface active and lowered the surface tension of high-pressure liquid chromatography-grade water from 72.96 to 29.8 mN m(-1). Similar to reports for other pore-forming cytotoxins, low concentrations of the hemolysin were able to induce nucleosomal degradation consistent with apoptosis in human neutrophils and the mouse-derived macrophage-type cell line J774.2. Exposure of human neutrophils to higher concentrations of toxin resulted in increased activities of the neutrophil degranulation markers cathepsin G and elastase. Based on the results obtained in this study, we suggest a role that allows B. cepacia to thwart the immune response and a model of the events that may contribute to the severe inflammatory response in the lungs of CF patients.
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PMID:Burkholderia cepacia produces a hemolysin that is capable of inducing apoptosis and degranulation of mammalian phagocytes. 957 86

Neutrophil elastase (NE) is a potent serine proteinase whose expression is limited to a narrow window during myeloid development. In neutrophils, NE is stored in azurophil granules along with other serine proteinases (cathepsin G, proteinase 3 and azurocidin) at concentrations exceeding 5 mM. As a result of its capacity to efficiently degrade extracellular matrix, NE has been implicated in a variety of destructive diseases. Indeed, while much interest has focused on the pathologic effects of this enzyme, little is known regarding its normal physiologic function(s). Because previous in vitro data have shown that NE exhibits antibacterial activity, we investigated the role of NE in host defense against bacteria. Generating strains of mice deficient in NE (NE-/-) by targeted mutagenesis, we show that NE-/- mice are more susceptible than their normal littermates to sepsis and death following intraperitoneal infection with Gram negative (Klebsiella pneumoniae and Escherichia coli) but not Gram positive (Staphylococcus aureus) bacteria. Our data indicate that neutrophils migrate normally to sites of infection in the absence of NE, but that NE is required for maximal intracellular killing of Gram negative bacteria by neutrophils.
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PMID:Mice lacking neutrophil elastase reveal impaired host defense against gram negative bacterial sepsis. 958 38

The purpose of this review-hypothesis is to discuss the literature which had proposed the concept that the mechanisms by which infectious and inflammatory processes induce cell and tissue injury, in vivo, might paradoxically involve a deleterious synergistic 'cross-talk', among microbial- and host-derived pro-inflammatory agonists. This argument is based on studies of the mechanisms of tissue damage caused by catalase-negative group A hemolytic streptococci and also on a large body of evidence describing synergistic interactions among a multiplicity of agonists leading to cell and tissue damage in inflammatory and infectious processes. A very rapid cell damage (necrosis), accompanied by the release of large amounts of arachidonic acid and metabolites, could be induced when subtoxic amounts of oxidants (superoxide, oxidants generated by xanthine-xanthine oxidase, HOCl, NO), synergized with subtoxic amounts of a large series of membrane-perforating agents (streptococcal and other bacterial-derived hemolysins, phospholipases A2 and C, lysophosphatides, cationic proteins, fatty acids, xenobiotics, the attack complex of complement and certain cytokines). Subtoxic amounts of proteinases (elastase, cathepsin G, plasmin, trypsin) very dramatically further enhanced cell damage induced by combinations between oxidants and the membrane perforators. Thus, irrespective of the source of agonists, whether derived from microorganisms or from the hosts, a triad comprised of an oxidant, a membrane perforator, and a proteinase constitutes a potent cytolytic cocktail the activity of which may be further enhanced by certain cytokines. The role played by non-biodegradable microbial cell wall components (lipopolysaccharide, lipoteichoic acid, peptidoglycan) released following polycation- and antibiotic-induced bacteriolysis in the activation of macrophages to release oxidants, cytolytic cytokines and NO is also discussed in relation to the pathophysiology of granulomatous inflammation and sepsis. The recent failures to prevent septic shock by the administration of only single antagonists is disconcerting. It suggests, however, that since tissue damage in post-infectious syndromes is caused by synergistic interactions among a multiplicity of agents, only cocktails of appropriate antagonists, if administered at the early phase of infection and to patients at high risk, might prevent the development of post-infectious syndromes.
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PMID:Can we learn from the pathogenetic strategies of group A hemolytic streptococci how tissues are injured and organs fail in post-infectious and inflammatory sequelae? 1049 63


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