Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P05231 (interleukin-6)
 23,907 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have previously shown that the synthetic tetraacyl precursor Ia (compound 406, LA-14-PP, or lipid IVa) was not able to induce the production of tumor necrosis factor, interleukin-1, and interleukin-6 in human monocytes but strongly antagonized lipopolysaccharide (LPS)-induced formation of these monokines. This inhibition was detectable at the level of mRNA production. To achieve a better understanding of molecular basis of this inhibition, we investigated whether lipid A precursor Ia (LA-14-PP), Escherichia coli-type lipid A (LA-15-PP), Chromobacterium violaceum-type lipid A (LA-22-PP), and synthetic lipid A partial structures and analogs (LA-23-PP, LA-24-PP, and PE-4) were able to influence the binding of 125I-LPS to human monocytes and compared this inhibitory activity with the agonistic and antagonistic action in the induction of monokines in human monocytes. 125I-LPS (20 ng per well) was added to human monocytes in the presence or absence of unlabeled rough Re mutant-derived LPS (Re-LPS) or lipid A compounds, and specific LPS binding was determined after 7 h. This binding was found to be dependent on CD14 as shown by the use of an anti-CD14 monoclonal antibody. Compound LA-14-PP was found to inhibit the binding of 125I-LPS to the cells in a similar dose-response to that of unlabeled LPS. This shows that the inhibitory capacity on LPS binding does not correlate with the monokine-inducing capacity because Re-LPS is active in inducing tumor necrosis factor, interleukin-1, and interleukin-6, while LA-14-PP is not. The strong capacity of LA-14-PP to inhibit 125I-LPS binding, however, correlates with the strong inhibitory capacity of this compound on LPS-induced monokine production. Compounds LA-15-PP, LA-23-PP, and LA-24-PP were active in the inhibition of 125I-LPS binding but were 5- to 10-fold weaker than Re-LPS and LA-14-PP. Of all lipid A structures tested, compound LA-22-PP expressed the weakest inhibitory capacity on LPS binding. These compounds showed again that the activity of binding inhibition does not correlate with the monokine-inducing capacity. We assume that the inhibitory effects of lipid A partial structures on LPS-induced monokine production have their origin in a competitive inhibition between LPS and the lipid A partial structures for the same binding site on the cell membrane.
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PMID:Modulation of endotoxin-induced monokine release in human monocytes by lipid A partial structures that inhibit binding of 125I-lipopolysaccharide. 128 Jun 25

Endotoxin (lipopolysaccharide, LPS) has the property of inducing tolerance to its own biological effects. This phenomenon has been extensively studied in animal models but only few studies exist on the regulation in humans. Here we describe experiments designed to determine the cytokine regulation and cellular changes in humans during induction of LPS tolerance after repeated LPS injections. Intravenous administration of purified LPS Salmonella abortus equi to cancer patients induces high amounts of circulating tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), interleukin-8 (IL-8), granulocyte colony-stimulating factor (G-CSF), and macrophage colony-stimulating factor (M-CSF). Repeated injections of LPS at daily intervals resulted in a marked downregulation of the cytokine response and in the case of TNF-alpha, IL-8, G-CSF, and M-CSF the cytokine response was reduced to baseline levels. In contrast, significant increases in serum IL-6 were detected up to day 5 of repeated LPS injections. Hematological changes included transient decreases in WBCs affecting granulocytes, monocytes, and lymphocytes, followed by a marked granulocytosis. The drop in WBCs remained unaltered throughout the 5 day course of repeated LPS injections whereas the granulocyte overshoot recovery diminished gradually. When PBMCs of the cancer patients were restimulated ex vivo a marked enhancement of the capacity to produce TNF-alpha, IL-113, and IL-6 occurred, which is in contrast to the decreasing TNF-alpha serum levels obtained in vivo. In parallel, a shift in monocyte subpopulations from CD14+/CD16- to CD14+/CD16+ cells was observed. The data provide evidence that different mechanisms are implicated in the cytokine downregulation following repeated LPS injections to cancer patients. Furthermore, PBMCs from LPS tolerant patients do not demonstrate a reduction in their capacity to produce cytokines.
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PMID:Endotoxin tolerance: regulation of cytokine production and cellular changes in response to endotoxin application in cancer patients. 128 77

There is, at present, considerable interest in the possible role for the proinflammatory cytokines, tumor necrosis factor-alpha, interleukin-1, interleukin-6, and interferon-gamma in the pathogenesis of cancer cachexia. Indirect evidence for such a role is based on the observation that chronic administration of many of these cytokines, either alone or in combination, can reproduce the myriad of host responses seen in experimental and human cancer cachexia. Elevated plasma levels of tumor necrosis factor-alpha, interleukin-2, and interferon-gamma have rarely been detected in patients or experimental animals with cancer, although interleukin-6 levels appear to correlate with tumor progression in animal models. The strongest evidence for a causal role for cytokines has come from rodent studies in which tumor-bearing animals have been passively immunized with antibodies directed against individual cytokines. Several groups have shown modest but significant improvements in food intake and lean tissue retention with antibodies directed against tumor necrosis factor-alpha, interleukin-1, interleukin-6, and interferon-gamma. However, there has been no consistent finding that one cytokine is universally involved in cancer cachexia in histologically distinct tumor models. One ominous finding in several tumor models has been that the endogenous production of cytokines appears to support tumor growth. Such findings raise the intriguing possibility that these cytokines, although contributors to tissue wasting and anorexia, may also serve the tumor as either direct or indirect cell growth factors.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The role of cytokines in cancer cachexia. 128 23

Cancer cachexia describes a syndrome that consists of weight loss, and abnormalities in carbohydrate, protein, and lipid metabolism, which result in a state of persistent net negative energy balance. Patients suffering from cancer cachexia have a significantly shortened survival after cancer treatment. Recent experimental studies have focused on the belief that the mechanisms of cancer cachexia involve the host's production of inflammatory cytokines, which through broad physiologic actions ultimately lead to a chronic state of wasting, malnourishment, and death. Cytokines that have been thought to play a role in the pathophysiology of cachexia include tumor necrosis factor, interleukin-1, interleukin-6, interferon-gamma and differentiation factor. It has become clear that these cytokines have overlapping physiologic activities, which makes it likely that no single substance is the sole cause of cachexia in most cancer patients. Only further investigation may make it possible to more clearly define the role of cytokines in the pathophysiology of cancer cachexia. Specific strategies to reverse the cachectic effects of these substances may then be developed to ultimately improve cancer treatment.
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PMID:Cytokines and their role in the pathophysiology of cancer cachexia. 128 24

In vitro plasma perfusion experiments were performed using small columns containing either resin or charcoal adsorbents to assess the removal of cytokines and endotoxin. 125I-labelled tumor necrosis factor-alpha (TNF-alpha; 500 pg/ml) and interleukin-6 (IL-6; 10 ng/ml) were added individually to human plasma. Over 4 hr of perfusion, Amberlite XAD-7 resin removed 32.5% +/- 3.3% (n = 5) of the initial amount of TNF-alpha and 71.4% +/- 3.8% (n = 5) of the initial amount of IL-6. DHP-1 polyhema-coated activated charcoal removed 17.2% +/- 6.2% (n = 5) of TNF-alpha and 48.5% +/- 7.4% (n = 5) of IL-6. Preliminary experiments were performed with lipopolysaccharide (LPS; 100 ng/ml) and interleukin-1 alpha (IL-1 alpha; 500 pg/ml), which showed that, over 4 hr, Amberlite XAD-7 removed 10.3% of the initial LPS and 29.1% of IL-1 alpha, whereas DHP-1 charcoal removed 23.2% of the initial LPS and 65.3% of IL-1 alpha. In vitro plasma ultrafiltration with either polysulfone or polyacrylonitrile membranes, as used clinically in haemodialysis, was performed with recirculation of plasma containing LPS or TNF-alpha. Neither of the substances was filtered to a significant degree. In conclusion, direct removal of these inflammatory mediators from the circulation of patients with multiorgan failure due to fulminant hepatic failure or sepsis would be possible by perfusion of plasma through adsorbents but not by haemodialysis.
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PMID:In vitro plasma perfusion through adsorbents and plasma ultrafiltration to remove endotoxin and cytokines. 129 81

Cytokines at an inflammatory site may be a better indicator of the clinical severity of an infectious disease than the serum levels of the cytokines. Concentrations of interleukin-1 beta (IL-1 beta) in paired samples of cerebrospinal fluid (CSF) from 10 rabbits with experimental bacterial meningitis caused by H. influenzae type b, were measured, and compared to the concentrations of four cytokines; IL-1 beta, interleukin-6 (IL-6), interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-alpha) in CSF samples from 45 children with or without meningitis. The IL-1 beta concentrations in the CSF from rabbits with experimental meningitis were significantly higher than the concentrations in control animals without meningitis (p < 0.001). The mean CSF concentrations of IL-8 from meningitic children were significantly higher than in the control group without meningitis (p < 0.005). TNF-alpha was only detected in septic meningitis. Assays of IL-6, however, were not significantly different in the septic meningitis group, the aseptic meningitis group and the non-meningitis group. These data indicate a possible role of IL-1 beta, IL-8 and TNF-alpha as mediators in the meningeal inflammatory process in patients with meningitis and TNF-alpha, in particular, may play a role in the pathogenesis of septic meningitis.
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PMID:Concentrations of interleukin-1 beta, interleukin-6, interleukin-8 and TNF-alpha in cerebrospinal fluid from children with septic or aseptic meningitis. 130 8

The effects of hormones and cytokines on angiotensinogen production were studied in primary cultured rat hepatocytes. The basal secretion of angiotensinogen decreased during culture. The addition of dexamethasone and (Bu)2cAMP completely prevented this decrease. Angiotensinogen secretion by freshly plated hepatocytes was slightly increased in response to dexamethasone, but after 24 h in culture, hepatocytes no longer responded to dexamethasone alone. When hepatocytes were treated with (Bu)2cAMP, glucagon, or forskolin, angiotensinogen secretion increased in response to dexamethasone in a concentration-dependent manner. 17 beta-Estradiol and T3 failed to stimulate angiotensinogen secretion in either the presence or absence of (Bu)2cAMP. Interleukin-6 (IL-6) exhibited a stimulatory activity on angiotensinogen secretion, which was dependent on the presence of dexamethasone, whereas IL-1 and tumor necrosis factor had no effect in either the presence or absence of dexamethasone and/or (Bu)2cAMP. Unlike primary cultured hepatocytes, angiotensinogen secretion by rat hepatoma H4IIEC3 cells increased in response to dexamethasone alone. This increase was not enhanced by (Bu)2cAMP, but was enhanced by IL-6. Thus, in primary cultures of rat hepatocytes, neither glucocorticoid, cAMP, nor IL-6 alone stimulated angiotensinogen production, but a combination of glucocorticoid and cAMP or of glucocorticoid and IL-6 exhibited a stimulatory activity on angiotensinogen production. These results suggest that angiotensinogen production in the liver is synergistically regulated by these factors, whereas the hepatoma cell line H4IIEC3 lacks the regulatory mechanism of cAMP on glucocorticoid-induced angiotensinogen production.
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PMID:Stimulation of angiotensinogen production in primary cultures of rat hepatocytes by glucocorticoid, cyclic adenosine 3',5'-monophosphate, and interleukin-6. 131 Dec 38

Several hormones and cytokines stimulate the cellular Na+/H+ antiporter and this stimulation may be a signal transduction mechanism to mediate gene expression. We find that tumor necrosis factor rapidly stimulates both the Na+/H+ antiporter and the accumulation of mRNA coding for granulocyte-macrophage colony-stimulating factor and interleukin-6 in fibroblasts. Further experiments show that these phenomena occur independent of each other.
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PMID:Tumor necrosis factor stimulates Na+/H+ antiporter in human fibroblasts: dissociation between intracellular alkalinization and cytokine mRNA accumulation. 131 73

Recent reports show that cytokines such as interleukin-1 (IL-1), tumor necrosis factor (TNF) and intravenously administered interleukin-6 (IL-6) stimulate adrenocorticotropic hormone (ACTH) release. Both IL-1 and TNF are known to be potent inducers of IL-6, a monokine produced by activated monocytes and folliculo-stellate cells of the pituitary gland and released from the hypothalamus. To determine the site(s) of action of IL-6 in the control of ACTH release, we injected human recombinant IL-6 into the third brain ventricle (3V) of freely moving, conscious male rats and measured ACTH by RIA. Both 0.05 pmole and 0.25 pmole doses of IL-6 were ineffective to change plasma ACTH in comparison to the values in controls. The maximal IL-6 dose tested of 1.25 pmole increased plasma ACTH within 15 min and the response lasted over 180 min. The effects of IL-6 on plasma ACTH were only partially paralleled by increased rectal temperature which suggests that hypothalamic temperature regulating centers were independent of these actions. To evaluate a possible direct effect on the pituitary, IL-6 was incubated in vitro with hemipituitaries under an atmosphere of 95% O2/5% CO2. After 1 hr of incubation IL-6 failed to cause any change in the secretion of ACTH throughout a concentration range of 10(-15) to 10(-9) M. Increased ACTH secretion into the incubation medium was found only with 10(-13) M IL-6 after a 2-hr incubation. The results support a possible role for IL-6 at both hypothalamic and/or pituitary levels to stimulate ACTH release.
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PMID:Induction of adrenocorticotropic hormone release by interleukin-6 in vivo and in vitro. 131 56

In order to determine the in vivo immune response in glioblastoma, monoclonal and polyclonal antibodies specific for inflammatory leukocytes and immunoregulatory products were utilized to stain tissue from four surgical specimens. The more activated the inflammatory cells, the more activated the tumors appeared to be. In the tumor with the largest infiltration (Case 3), inflammatory cells were stained for interferon-gamma, interleukin-2, interleukin-1 beta, lymphotoxin, tumor necrosis factor-alpha, and transforming growth factor-beta. The tumor cells also expressed interleukin-1 beta, interleukin-6, transforming growth factor-beta, tumor necrosis factor-alpha, and prostaglandin E. In contrast, in the tumor with the least inflammatory response (Case 1), the tumor cells did not express any cytokines. Expression of cytokines by glioma cells was modest in the two cases with modest inflammatory responses. Cellular inflammation, primarily consisting of T cells and macrophages with few or no B cells or natural killer cells, was two- to 15-fold greater outside the tumor than within. In contrast to leukocytes outside the tumor, which were activated and expressing class II major histocompatibility antigens, leukocytes within the tumor parenchyma or at the tumor's edge were negative for these antigens. In the four specimens studied here, the tumor cells themselves were also negative for class II major histocompatibility antigens. These findings, although preliminary, suggest that inflammatory cells within gliomas are inactivated and that glioma cells may increase the expression of immunosuppressive cytokines in response to an increased lymphocyte infiltrate. This observation, if corroborated by more extensive studies, may help to explain the failure of immune treatments in glioblastoma multiforme.
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PMID:Inflammatory leukocytes associated with increased immunosuppression by glioblastoma. 131 61


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