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)

Leishmania are parasites that survive within macrophages by mechanism(s) not entirely known. Depression of cellular immunity and diminished production of interleukin 1 beta (IL-1 beta) and tumor necrosis factor alpha are potential ways by which the parasite survives within macrophages. We examined the mechanism(s) by which lipophosphoglycan (LPG), a major glycolipid of Leishmania, perturbs cytokine gene expression. LPG treatment of THP-1 monocytes suppressed endotoxin induction of IL-1 beta steady-state mRNA by greater than 90%, while having no effect on the expression of a control gene. The addition of LPG 2 h before or 2 h after endotoxin challenge significantly suppressed steady-state IL-1 beta mRNA by 90% and 70%, respectively. LPG also inhibited tumor necrosis factor alpha and Staphylococcus induction of IL-1 beta gene expression. The inhibitory effect of LPG is agonist-specific because LPG did not suppress the induction of IL-1 beta mRNA by phorbol 12-myristate 13-acetate. A unique DNA sequence located within the -310 to -57 nucleotide region of the IL-1 beta promoter was found to mediate LPG's inhibitory activity. The requirement for the -310 to -57 promoter gene sequence for LPG's effect is demonstrated by the abrogation of LPG's inhibitory activity by truncation or deletion of the -310 to -57 promoter gene sequence. Furthermore, the minimal IL-1 beta promoter (positions -310 to +15) mediated LPG's inhibitory activity with dose and kinetic profiles that were similar to LPG's suppression of steady-state IL-1 beta mRNA. These findings delineated a promoter gene sequence that responds to LPG to act as a "gene silencer", a function, to our knowledge, not previously described. LPG's inhibitory activity for several mediators of inflammation and the persistence of significant inhibitory activity 2 h after endotoxin challenge suggest that LPG has therapeutic potential and may be exploited for therapy of sepsis, acute respiratory distress syndrome, and autoimmune diseases.
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PMID:Lipophosphoglycan from Leishmania suppresses agonist-induced interleukin 1 beta gene expression in human monocytes via a unique promoter sequence. 896 19

Our previous studies have shown that rat pulmonary microvascular smooth muscle cells (RPMSMC) upregulate inducible nitric oxide synthase (iNOS) and produce nitric oxide (NO) when treated with interleukin-1 beta (IL-1 beta). We now report that an additional effect of IL-1 beta stimulation in RPMSMC is an increase in production of superoxide (O2-) that results in the formation of peroxynitrite (ONOO-). IL-1 beta produced a rapid (within 1 h) concentration-dependent increase in O2-, as detected by ferricytochrome c reduction and lucigenin-enhanced chemiluminescence. O2- production was sensitive to quinacrine and diphenyliodinium, suggesting that NADH and NADPH oxidoreductases were responsible. After induction of iNOS and production of iNOS-derived NO, ONOO- was detected by luminol-enhanced chemiluminescence and was found to cause lipid peroxidation and to form nitrotyrosine in the cytoskeleton, detected by immunostaining. Cell viability, however, appeared to be unaffected. IL-1 beta-mediated induction of RPMSMC-derived ONOO- may have significant effects on pulmonary vascular function in sepsis and inflammatory states.
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PMID:IL-1 beta stimulates superoxide and delayed peroxynitrite production by pulmonary vascular smooth muscle cells. 899 63

Patients with severe granulocytopenia are more susceptible to severe infections and sepsis. Proinflammatory cytokines such as tumor necrosis factor-alpha (TNF), interleukin-1 alpha (IL-1 alpha), and IL-1 beta play an important role in the pathophysiology of sepsis. The profile of these proinflammatory cytokines after lipopolysaccharide (LPS) challenge in cyclophosphamide-induced neutropenic mice was assessed, and possible mechanisms responsible for the modified cytokine production were studied. After LPS, both circulating concentrations of TNF and IL-1 alpha in neutropenic mice were 50% to 200% higher than those of controls, whereas IL-1 beta concentrations were not modified. The kinetics of cytokine production were similar in neutropenic and control animals. The susceptibility of neutropenic mice to an LPS challenge was increased. The observed overproduction of TNF and IL-1 alpha was not due to a direct effect of cyclophosphamide treatment. Because circulating concentrations of uric acid were increased in the neutropenic mice, the effect of hypouricemic treatment with allopurinol and sodium bicarbonate was investigated; such treatment in neutropenic mice challenged with LPS was followed by an improved survival and a reduced proinflammatory cytokine production towards the concentrations in control mice. Hyperuricemia induced by repeated administrations of uric acid in normal mice led to an increased TNF production after LPS. In conclusion, neutropenic mice respond with enhanced cytokine production and increased susceptibility to an LPS challenge, and hyperuricemia probably plays an important role in this phenomenon.
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PMID:The role of hyperuricemia in the increased cytokine production after lipopolysaccharide challenge in neutropenic mice. 900 61

The effects of methyl palmitate (MP), a known inhibitor of Kupffer cells, were studied in a model of polymicrobial sepsis induced in CD-1 mice by cecal ligation and puncture (CLP). The inhibition of Kupffer cells by pretreatment with MP was shown by the reduced phagocytosis, the production of tumor necrosis factor (TNF) and interleukin-6 (IL-6) after lipopolysaccharide (LPS) challenge. The reduced activation of Kupffer cells resulted in lower levels of inflammatory products after CLP. TNF and IL-6 were significantly reduced in serum 2 h and 24 h respectively after CLP, interleukin-1 beta (IL-1 beta) was reduced in liver 4 h after CLP, nitric oxide (NO) and serum amyloid A (SAA) were significantly reduced 8 and 24 h respectively after CLP. Liver toxicity was significantly reduced in MP-treated mice and survival was significantly prolonged at all intervals, reaching 45% after six to ten days compared with 3% in control mice. These findings suggest that Kupffer cells play an important role in liver damage and survival in sepsis.
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PMID:Effects of methyl palmitate on cytokine release, liver injury and survival in mice with sepsis. 901 Jun 79

Cytokines serve to initiate the acute inflammatory response and to integrate nonspecific and specific immunological responses to infections occurring in perioperative patients. Microbial substances induce macrophages to produce pivotal cytokines (TNF-alpha and IL-1 beta). This results in an activation of other cytokine productions including IL-2, IL-3, IL-4, IL-6, chemokines, and IL-10. Also, other host-originated humoral mediators are released from macrophages, neutrophils, platelets, and endothelial cells Various cytokines are also produced by helper-T (Th) cells, and the Th1/Th2 balance is regulated by cytokines and stress hormones. This nonspecific inflammatory response and specific immunological response which are mediated by cytokines are crucial for the host defense against invading pathogens. On the other hand, the blood levels of TNF-alpha, IL-6, IL-8, and MIP-1 alpha were correlated with the severity and mortality in patients with sepsis. Also we found that in patients with inhalation injury the high IL-8 levels in bronchoalveolar lavage fluid on admission predicted the development of respiratory insufficiency. In severe infection, a systemic release of various cytokines is not properly regulated, and the high blood levels of the proinflammatory cytokines cause an autodestructive systemic inflammatory response syndrome (SIRS). This condition is termed "Cytokine Storm" by the author. In cytokine storm, not only proinflamamtory cytokines, but also anti-inflammatory cytokines appear in circulating blood, leading to septic shock, multiple organ dysfunction, and immunosuppression. With further understanding of the roles of cytokines in sepsis, modulation of cytokine responses could be a new modality of the treatment.
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PMID:[Cytokine-mediated biological response to severe infections in surgical patients]. 903 81

Soluble type II interleukin 1 receptor (IL-1r II) and interleukin 1 receptor antagonist (IL-1ra) regulate inflammation by competitively inhibiting the binding of IL-1 beta to the signalling IL-1 receptor. In addition, glucocorticoids also regulate IL-1 beta by suppressing gene transcription. More recently, glucocorticoids have been shown to increase soluble IL-1r II concentrations, which may contribute to their anti-inflammatory properties. Interestingly, increased serum levels of soluble IL-1r II and IL-1ra have been measured in septic patients, although the mechanism is unclear. In this respect, the authors characterize new pathways in which IL-1r II and IL-1ra may be regulated in sepsis through combined stimulation with lipopolysaccharide (LPS) and dexamethasone of peripheral blood mononuclear cells (PBMC). This paper confirms that while dexamethasone induces release of IL-1r II, LPS augments dexamethasone-induced IL-1r II release 45-fold. Furthermore, LPS plus dexamethasone induces IL-1r II protein and mRNA, whereas LPS alone does not. Additionally, it was shown by flow cytometric analysis that the monocyte is the primary IL-1r II producer in response to LPS and dexamethasone administration. Therefore, LPS and dexamethasone synergism in IL-1r II induction may be important in controlling IL-1 beta effects. In contrast, LPS alone induces IL-1ra, while dexamethasone attenuates this LPS-induced response. Although IL-1r II and IL-1ra may work together to suppress IL-1 beta effects in sepsis, inflammatory cells differentially regulate these cytokines.
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PMID:The combination of endotoxin and dexamethasone induces type II interleukin 1 receptor (IL-1r II) in monocytes: a comparison to interleukin 1 beta (IL-1 beta) and interleukin 1 receptor antagonist (IL-1ra). 904 79

Lipopolysaccharides (LPS) of gram-negative bacteria and superantigens of gram-positive bacteria are among the main causes of sepsis and septic shock. Symptoms are initiated primarily by the release of endogenous mediators, especially cytokines. In the last few years, increasing evidence for the clinical relevance of mixed sepsis caused by coinfections with both types of bacteria has been found. Therefore, we developed an in vitro mixed sepsis model investigating the effect of different superantigen doses, in combination with different LPS concentrations, on cytokine production in human PBMCs using ELISA and RT-PCR. Low, in vivo relevant concentrations of the superantigen toxic shock syndrome toxin-1 (TSST-1) synergistically enhance LPS-induced production of interferon-gamma (IFN-gamma) interleukin-1 beta (IL-1 beta), IL-6, and IL-10, but low LPS has no comparable effect. Signal transduction studies with different inhibitors suggest that this one-way synergism is caused by an interaction between the cAMP and the PIP2 signaling pathway. Furthermore, our findings support the idea that this interaction is one important crossover point of signal transduction pathways by LPS and superantigens, which seems to be predominantly regulated by IFN-gamma and PGE-2. The identification of additional crossover points in the genesis of a mixed sepsis and their selective influence could lead to identical treatment of both gram-negative and gram-positive sepsis.
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PMID:One-way synergistic effect of low superantigen concentrations on lipopolysaccharide-induced cytokine production. 914 52

Previous studies indicate a profound suppression of tumour necrosis factor alpha (TNF-gamma), IL-1 beta and IL-6 release capacity by peritoneal macrophage (PM phi), splenic macrophage (SM phi) and Kupffer cells (KC) during late sepsis. Such a loss of functional capacity may reduce the animal's ability to ward off infection. Prolactin is known to enhance monocyte, T- and B-lymphocyte immune responses under normal conditions and has beneficial effects on cell-mediated immunity after haemorrhage. In the respect, the dopamine antagonist, metoclopramide, has been reported to increase circulating prolactin levels. Nonetheless, it remains unknown whether prolactin or metoclopramide have any salutary effect on macrophage (M phi) cytokine gene expression following sepsis. To study this, male C3H/HeN mice were subjected to sepsis and immediately thereafter were treated with prolactin (100 micrograms/25 g body weight, s.c.), metoclopramide (100 micrograms/100 g BW, s.c.) or given saline. PM phi, SM phi and KC (only SM phi and KC in metoclopramide-treated animals) were isolated at 24 h after sepsis. The monolayers were stimulated with or without LPS 10 micrograms/ml for 1 h in vitro. Total RNA was extracted and mRNA was detected by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). A significant depression of constitutive and inducible mRNA levels of IL-1 beta, IL-6 and TNF-alpha in all three M phi populations were observed, when compared with shams (with exception of KC IL-6 mRNA in unstimulated cells). Prolactin as well as metoclopramide treatment after the onset of sepsis caused significant elevation of constitutive and inducible cytokine gene expression in all macrophages examined. Thus, prolactin and metoclopramide enhance the depressed M phi gene expression and may be useful in improving cell-mediated immunity during sepsis.
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PMID:Effects of prolactin and metoclopramide on macrophage cytokine gene expression in late sepsis. 919 78

Interleukin(IL)-13, a cytokine produced by T helper 2 (Th2) cells, is a powerful inhibitor of macrophage functions, including surface expression of CD14 and production of IL-1 and tumor necrosis factor (TNF)-alpha. We tested the effects of recombinant mouse(m)IL-13 in a neonatal mouse model of endotoxin shock; this is a macrophage-dependent condition, which is a model of neonatal sepsis in humans. mIL-13 (0.5 microgram/mouse) dramatically reduced the lethal effects of lipopolysaccharide (LPS) if administered either 24 or 4 h prior to or concomitantly with LPS challenge. This action might be mediated by multiple modulatory activities of IL-13 on LPS-induced cytokine secretion since, relative to control animals, the mice treated with mIL-13 had eight times lower peak blood levels of TNF. The IL-1 beta levels were also decreased, whereas increased levels of IL-6 and IL-10 were observed at several time points after LPS challenge.
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PMID:Prevention of endotoxin-induced lethality in neonatal mice by interleukin-13. 920 14

Early release of macrophage-derived proinflammatory cytokines, such as tumor necrosis factor (TNF), interleukin (IL)-1, and IL-6, are important in the pathogenesis of septic shock and multisystem organ failure in various models of sepsis. IL-10 is a mediator that inhibits cytokine release from activated macrophages. The aim of this study was to determine if IL-10 would decrease serum cytokine elevation in a murine model of cecal ligation and puncture (CLP). CLP in animals is a model that closely mimics the physiologic changes seen in human sepsis. Four groups of 14 female Swiss-Webster mice were used. Group 1 underwent laparotomy alone, groups 2, 3, and 4 underwent laparotomy and CLP. Groups 1 and 2 received intraperitoneal (IP) saline injections to serve as control vehicle. Group 3 (prophylactic) received 10,000 U IP IL-10 1 hr prior to CLP and every 3 hr thereafter. Group 4 (therapeutic) received 10,000 U IP IL-10 1 hr following CLP and every 3 hr thereafter. Animals were sacrificed at 3 and 9 hr following CLP. Serum TNF-alpha, IL-1 beta, and IL-6 were determined by enzyme-linked immunosorbent assay (ELISA), CLP produced a significant rise in serum TNF,IL-6, and IL-1 in untreated controls. Prophylactic or therapeutic administration of IL-10 significantly attenuated this early rise in serum cytokines. These results support the hypothesis that (1) CLP produces an early systemic rise in macrophage-derived cytokines and (2) IL-10 given either before or after the onset of CLP-induced intraabdominal infection and sepsis is able to inhibit this early release of macrophage-derived systemic mediators. IL-10 has potential clinical benefits in the therapeutic management of intraabdominal infection and sepsis.
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PMID:Interleukin-10 prevents early cytokine release in severe intraabdominal infection and sepsis. 923 83


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