Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011570 (depression)
172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Escherichia coli bacteria expressing mannose-resistant fimbriae/haemagglutination induced the production of substantial amounts of tumour necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) from a peripheral human lymphocyte, monocyte, basophil (LMB) cell suspension. In this regard, E. coli bacteria with S-mannose-resistant fimbriae/haemagglutination were the most potent inducers of IL-6 and TNF-alpha secretion, followed by the E. coli strain with P-mannose-resistant fimbriae/haemagglutination. The E. coli alpha-haemolysin did not stimulate cytokine release from human LMB. In fact, this toxin, at non-toxic concentrations, depressed the spontaneous as well as the E. coli-induced production of TNF-alpha, IL-6, IL-1 beta. Our results indicate that two mechanisms may contribute to the severity of E. coli infection: (a) stimulation of cytokine release by type-specific fimbriae/haemagglutination properties and (b) depression of immune response by the E. coli alpha-haemolysin.
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PMID:Induction and suppression of cytokine release (tumour necrosis factor-alpha; interleukin-6, interleukin-1 beta) by Escherichia coli pathogenicity factors (adhesions, alpha-haemolysin). 849 69

Immunization with live measles virus vaccine produces transient depression of delayed-type hypersensitivity (DTH) skin test responses and mitogen-induced lymphoproliferation irrespective of the serostatus of the recipient of the vaccine. To investigate this immune suppression further we studied peripheral blood mononuclear cells (PBMC) from adults before (N = 17) and at various times after (N = 34) immunization with measles virus vaccine. PHA-induced lymphoproliferation was decreased after vaccine and this was partly reversed by supplementation with rIL-2. There was no change in the proportion of PBMC that were CD4+ T cells, CD8+ T cells, NK cells, or B cells as analyzed by flow cytometry. Supernatant fluids were collected from PBMC after 72 hr in culture. Analysis for cytokines after vaccination showed spontaneous production of high levels of IL-4 (vaccinees 99 +/- 23; controls 5.6 +/- 5.6 ng/ml, P = 0.031) and TNF alpha (vaccinees 140 +/- 45; controls 42 +/- 14 pg/ml, P = 0.072) accompanied by low levels of IFN-gamma (vaccinees 1.3 +/- 0.6; controls 14.3 +/- 10.1 U/ml), IL-1 alpha (vaccinees 111 +/- 22; controls 442 +/- 107 pg/ml, P = 0.0001), and PGE2 (vaccinees 75 +/- 39; controls 300 +/- 72 pg/ml, P = 0.048). Increased amounts of IL-4 were also produced after stimulation with PHA (vaccinees 140 +/- 25; controls 40 +/- 40 ng/ml, P = 0.013) while levels of IFN-gamma and soluble IL-2 receptor were similar to controls and levels of IL-1 alpha (vaccinees 443 +/- 67; controls 792 +/- 118 pg/ml, P = 0.026) remained low. Addition of rIL-2 had little effect on these cytokine levels. These data suggest that Th2 cells producing IL-4 are preferentially activated by measures vaccine and may contribute to the immunologic abnormalities associated with immunization for measles and possibly other viral infections.
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PMID:Changes in cytokine production after measles virus vaccination: predominant production of IL-4 suggests induction of a Th2 response. 851 92

Studies have shown that Kupffer cell and splenic macrophage, as well as peritoneal macrophage antigen presentation function, was significantly depressed following hemorrhage and remained so for at least 96 hours after resuscitation. Although macrophage antigen presentation was depressed, in all the cell populations studied, it was only the Kupffer cells which were upregulated to produce increased inflammatory cytokines. Furthermore, Kupffer cells from hemorrhaged animals exhibited enhanced, as opposed to reduced toxicity by peritoneal and splenic macrophages. This correlated well with increased cell-associated TNF on Kupffer cells. as well as increased capacity of Kupffer cells to release inflammatory cytokines after hemorrhage. It, therefore, could be postulated that while the enhanced Kupffer cell cytotoxicity may be beneficial in the destruction of pathogens seen in the liver due to bacterial translocation, this same activity may also contribute directly or indirectly to hepatocellular dysfunction and injury which is seen following hemorrhagic shock. Nonetheless, the depression in various immune functions after hemorrhage and resuscitation was comparable in both endotoxin-tolerant and -intolerant mice. Thus, it is debatable whether the alterations in immune function seen after hemorrhage are primarily due to the release of endotoxin into the blood stream during and/or following the hemorrhagic insult. Although translocation and/or endotoxemia occurs following severe hemorrhage, endotoxin may not be the sole or primary agent responsible for the induction of immunodepression after hemorrhage. The depressed Kupffer cell functions and increased inflammatory cytokine release by these cells can be significantly improved by post-treatment of animals with chloroquine, ibuprofen, diltiazem or ATP-MgCl2. Thus, these agents offer new therapeutic modalities in restoring the depressed Kupffer cell immune functions and in the treatment of generalized immunosuppression, as well as for decreasing the susceptibility to sepsis which is observed following severe blood loss.
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PMID:The role of bacterial translocation on Kupffer cell immune function following hemorrhage. 852 26

Activation of immune cells by pathogens induces the release of a variety of proinflammatory cytokines, including IL-1 beta and TNF-alpha. Previous studies using IL-1 beta have demonstrated that this cytokine can alter brain function, resulting in a variety of 'illness responses' including increased sleep, decreased food intake, fever, etc. We have recently demonstrated that i.p. IL-1 beta also produces hyperalgesia and that this hyperalgesia (as well as most illness responses) is mediated via activation of subdiaphragmatic vagal afferents. The present series of studies were designed to provide an initial examination of the generality of proinflammatory cytokine-induced hyperalgesia by examining the effects of i.p. TNF-alpha on pain responsivity. These studies demonstrate that: (a) i.p. TNF-alpha produces dose-dependent hyperalgesia as measured by the tailflick test, (b) this hyperalgesia is mediated via the induced release of IL-1 beta, (c) hyperalgesia is mediated via activation of subdiaphragmatic vagal afferents, and (d) the effects of subdiaphragmatic vagotomy cannot be explained by a generalized depression of neural excitability.
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PMID:Mechanisms of tumor necrosis factor-alpha (TNF-alpha) hyperalgesia. 854 10

Chronic exposure of humans to benzene causes severe bone marrow cell depression leading to aplastic anemia. Marrow stromal macrophage dysfunction and deficient interleukin-1 production has been reported for patients with severe aplastic anemia. The stromal macrophage, a target of benzene toxicity, is involved in hematopoietic regulation through the synthesis of several cytokines including interleukin-1, which is required for production by stromal fibroblasts of a number of cytokines required for the survival of hematopoietic progenitor cells. We have previously demonstrated that hydroquinone, a major toxic metabolite of benzene in marrow, prevents the proteolytic conversion of 31 kDa pre-interleukin-1 alpha to the 17 kDa cytokine by calpain in purified murine stromal macrophages. Furthermore, stromal macrophages from benzene-treated mice produce the 31 kDa pre-interleukin-1 alpha when stimulated in culture with endotoxin, but cannot convert the precursor to interleukin-1 alpha. In this report, we show that 1,4-benzoquinone, the oxidation product of hydroquinone in the cell, causes a concentration-dependent inhibition of highly purified human platelet calpain with an IC50 of 3 microM. Hydroquinone also inhibits the processing of pre-interleukin-1 beta by interleukin-1 beta convertase. The addition of 2 microM hydroquinone to B1 cells that undergo autocrine stimulation by interleukin-1 beta resulted in the cessation of autocrine cell growth and interleukin-1 beta secretion into the culture medium, as determined by Western immunoblots of the culture supernatants. Purified converting enzyme treated with 3 microM benzoquinone was incapable of converting 31 kDa recombinant pre-interleukin-1 beta to the 17 kDa mature cytokine as analyzed by polyacrylamide gel electrophoresis and Western immunoblotting. These findings support our observations in a mouse model that benzene-induced bone marrow cell depression results from a lack of interleukin-1 alpha subsequent to an inhibition by benzoquinone of calpain, the protease required for converting pre-interleukin-1 alpha to active cytokine. The results may provide a basis for studying benzene-induced aplastic anemia in a mouse model.
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PMID:Inhibition of the conversion of pre-interleukins-1 alpha and 1 beta to mature cytokines by p-benzoquinone, a metabolite of benzene. 854 60

Treatment with rapamycin (RPM) prevents accelerated rejection of (LEW x BN)F1 cardiac allografts in LEW rats presensitized with BN skin grafts. This study analyzed the influence of RPM on cytokine (IL-2, IL-4, IL-10, and IL-12) and alloantibody networks in this model. Accelerated (24-h) rejection was associated with strong expression of intragraft IL-2 and IL-12 (p40) mRNAs, which reached maximal levels 3 to 6 h post-transplantation. IL-4 and IL-10 mRNAs were readily detectable throughout the observation period. RPM therapy abrogated rejection at 24 h and prolonged cardiac allograft survival to about 50 days. This effect was correlated with a profound initial depression of IL-2 mRNA; delayed expression of IL-2 mRNA was detected in well functioning grafts at > 20 days. In RPM-treated hosts, expression of IL-12 (p40) mRNA was low at the early time points (6-24 h), but prominent in long term grafts. The expression of both IL-4 and IL-10 mRNAs was preserved in RPM-conditioned hosts. Immunohistologic analysis of long term allografts revealed an interstitial cellular infiltrate and areas of intimal proliferation within small arteries indicative of early transplant arteriosclerosis. Analysis of cytokine proteins showed dense labeling of mononuclear and some endothelial cells for IL-4 and IL-12 (p70), but not for IL-2 or IFN-gamma alloantibody in the early post-transplant period. However, an increase in circulating and intragraft IgM and, to a lesser extent, IgG, primarily of the IgG2b subclass, was evident in long term recipients. Thus, RPM treatment reduces, but does not completely inhibit, the expression of Th1-type and preserves the expression of Th2-type cytokines. The demonstration of IL-12 in long term allografts after RPM therapy may reflect late activation of macrophages that, coupled with the appearance of IgG2b, may contribute to the chronic rejection of cardiac allografts.
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PMID:Cytokine and alloantibody networks in long term cardiac allografts in rat recipients treated with rapamycin. 859 90

In paroxysmal nocturnal hemoglobinuria (PNH), little is known about the molecular events leading to the clinical manifestations except for the hemolysis. To unfold the complex pathophysiology, it is necessary to elucidate the nature of the PNH clone. PNH exhibits an acquired stem cell disorder, a clonal expansion of affected cells, concomitant depression of normal hematopoiesis in bone marrow (BM), and, although infrequently, the development of leukemia. The PNH clone is thus expected to exhibit some neoplastic features. We report here that CD34+ hematopoietic progenitor cells of PNH-BM yielded blood cells of three lineages with PNH phenotype alone when transplanted into sublethally irradiated severe combined immunedeficient mice. The hematopoiesis persisted for more than 10 months and did not always need human cytokines. In contrast, the hematopoiesis by control grafts obtained from healthy volunteers required an intense cytokine treatment. This in vivo model defines the preferential hematopoiesis of pluripotent PNH progenitor cells, indicating the intrinsic growth abnormality of PNH clone.
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PMID:Preferential hematopoiesis by paroxysmal nocturnal hemoglobinuria clone engrafted in SCID mice. 865 6

Proinflammatory cytokines play an important role in the depression of cytochrome P450 (CYP450)-dependent drug metabolism in mammals during inflammation and infection. Although much has been learned concerning the effects and mechanisms of cytokine-mediated suppression of CYP450, there is limited knowledge about how cytokines affect UDP glucuronosyl transferases (UDPGT). The aim of the present study was to investigate the effects and dose dependency of recombinant human proinflammatory cytokines on both CYP450- and UDPGT-dependent enzyme activities in primary cultures of pig hepatocytes. A possible role of nitric oxide in cytokine-induced suppression of enzyme activities was studied by incubating hepatocytes in the presence of N G-nitro-L-arginine (L-NAME), a competitive inhibitor of nitric oxide (NO) biosynthesis. Incubation of hepatocytes with interleukin-1alpha (IL-1alpha), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha) decreased both oxidation and glucuronidation activities dose dependently, in which the effects on glucuronidation activities were even more pronounced. IL-6 differed from IL-1alpha and TNF-alpha by inhibiting CYP450 and UDPFT more effectively after 24 hr of incubation, whereas the inhibition by IL-1alpha and TNF-alpha was more pronounced after 12 hr. Only at a concentration of 500 U/ml did interferon-gamma (IFN-ganna) inhibit CYP450 and UDPGT. The inhibition of CYP450 enzyme activities by cytokines was probably not due to the production of NO, because L-NAME totally blocked NO production but had no effect on the cytokine-induced suppression of CYP450 enzyme activities. However, there might be a role for NO in the decrease of glucuronidation by cytokines, as L-NAME slightly though significantly prevented the inhibition of glucuronidation.
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PMID:Suppression of cytochrome P450- and UDP glucuronosyl transferase-dependent enzyme activities by proinflammatory cytokines and possible role of nitric oxide in primary cultures of pig hepatocytes. 866 49

Proinflammatory cytokines are important mediators during endotoxemia. In experimental models, injection of lipopolysaccharide (LPS) activates macrophages leading to excessive secretion of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1 beta and IL-6; infusion of high dose of these mediators results in organ failure and death. Natural infection may be different, because it persists over days or even weeks, with repeated endotoxin challenge to macrophages. Little is known about the capacity of peripheral blood mononuclear cells (PBMCs) to release proinflammatory cytokines under these conditions. Therefore, as an ex vivo model of sepsis, the expression of proinflammatory cytokines after stimulation of whole blood with LPS was studied. A high LPS dose (1 microgram/ml) maximally increased TNF-alpha, IL-1 beta and IL-6 secretion in controls, but a marked depression was observed in septic patients (p < 0.01; 15 patients with severe sepsis versus 20 control patients without infection). This reduction persisted for up to 10 days after diagnosis of sepsis. The release of TNF-alpha, IL-1 beta and IL-6 was markedly decreased in the septic group even when a lower and physiologically more relevant LPS concentration (1 ng/ml) was used. IL-1 beta mRNA was similar to controls, but a down-regulation was observed in TNF-alpha and IL-6 transcript levels in PBMCs from the blood of septic patients. This was at least in part due to a marked reduction in TNF and IL-6 mRNA half-life. These results indicate that different mechanisms down-regulate proinflammatory cytokine release in the whole blood of septic patients. Although excessive secretion is known to be deleterious, low concentrations of these cytokines are involved in regulating essential cellular and humoral immune functions. Thus, the reduced capacity to express and release adequate amounts of proinflammatory cytokines after exposure to endotoxin, as observed in whole-blood PBMCs from septic patients, may contribute to the development of immunodeficiency.
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PMID:Interleukin-1, -6 and tumor necrosis factor-alpha release is down-regulated in whole blood from septic patients. 867 54

The thymoma cell line EL4.IL-2 (EL-4) was used as a T-cell model to assess the immunotoxic effects of several mycotoxins produced by the Aspergillus-Penicillium and the Fusarium groups. EL-4 cells were stimulated with phorbol 12-myristate 12-acetate (PMA) in the presence of mycotoxins at various concentrations for 5 d and culture supernatants were analyzed for interleukins (IL) IL-2 and IL-5 by enzyme-linked immunosorbent assay (ELISA). The cytokine effects were further related to proliferation and cell viability using the MTT [3-(4,5-dimethylthiazol-2-yl) 2,5-diphenyltetrazolium bromide] assay with absorbance at 570 nm (A570) as the endpoint indicator. IL-2 and IL-5 levels were dramatically increased by cyclopiazonic acid at 50-1000 ng/ml, whereas IL-2 was significantly decreased at 10 microgram/ml. Proliferation was slightly increased at 100-1000 ng/ml cyclopiazonic acid but markedly depressed at 5 and 10 microgram/ml. When EL-4 cells were exposed to 5 and 10 microgram/ml of ochratoxin A, IL-2 production was markedly increased while IL-5 production was significantly decreased. The A570 was significantly decreased by ochratoxin A at 10 microgram/ml. IL-2 and Il-5 production was almost totally suppressed by patulin at concentrations > or = 500 ng/ml and by T-2 toxin at > or = 5 ng/ml. These effects occurred concurrently with marked depression of A570 in the MTT assay. Although A570 was unaffected by either zearalenone or alpha-zearalenol exposure, both IL-2 and IL-5 levels were significantly elevated by these toxins at 5 or 10 microgram/ml. IL-2 and IL-5 production were not affected in EL-4 cells cultured with either the Aspergillus-Penicillium toxins aflatoxin B1 and secalonic acid or the Fusarium toxins wortmannin, fumonisin B1, or fusaric acid at concentrations up to 10 microgram/ml. In total, the EL-4 culture studies indicated that cyclopiazonic acid, ochratoxin A, zearalenone, and alpha-zearalenol could stimulate cytokine production whereas patulin and T-2 toxin were inhibitory. Cytokine dysregulation was not always related directly to perturbations in proliferation. The results suggest that the EL-4 thymoma cell line could be a simple and effective in vitro model for evaluating immunotoxicity of various classes of environmental chemicals.
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PMID:Effects of mycotoxins on cytokine production and proliferation in EL-4 thymoma cells. 869 8


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