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)

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

We investigated short-term alterations in plasma interleukin-6 (IL-6), interleukin-1beta (IL-1beta), and tumor necrosis factor alpha (TNF-alpha) levels induced by interferon alfa (IFN-alpha) injection in 18 patients with chronic hepatitis C. A single intramuscular injection of human recombinant IFN-alpha 2a (6 million units [MU]) significantly increased the plasma IL-6 level 6 hours after the injection (P < .05). On the other hand, the IFN-alpha injection did not affect the plasma TNF-alpha and IL-lbeta levels. Polymerase chain reaction (PCR) analysis showed accumulation of IL-6 gene transcripts in peripheral blood mononuclear cells (PBMC) after IFN-alpha injection, indicating that IFN-alpha enhances IL-6 production at the messenger RNA level. The induction of IL-6 by IFN-alpha was completely suppressed by the intravenous administration of gabexate mesilate (GM), a serine protease inhibitor. The mechanism whereby GM suppresses the elevation in circulating IL-6 levels seems to be the inhibition of IL-6 production at the messenger RNA level. Elevations of both serum C-reactive protein (CRP) levels and body temperature after GM-suppressed IFN-alpha injection suggest that the administration of GM by suppressing IL-6 production, may attenuate the IL-6-related responses induced by IFN-alpha injection. In conclusion, we found that IL-6 was induced by IFN-alpha in vivo, and that this induction was completely abrogated by the administration of GM. Our results indicate that serine protease inhibitors may be useful for inhibiting IL-6-relating responses.
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PMID:Induction of interleukin-6 by interferon alfa and its abrogation by a serine protease inhibitor in patients with chronic hepatitis C. 866 16

Human peripheral blood leukocytes (hPBL) are a rich source of natural leukocyte interferon (IFN-alpha) when treated with Sendai virus. Sendai virus treatment of hPBL will also result in significant production of several chemokines and cytokines such as macrophage inflammatory protein-1alpha (MIP-1alpha), MIP-1beta, RANTES, tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and IL-8, in a time-dependent way. A significant amount of MCP-1 is constitutively produced in overnight culture of leukocytes. The most abundant cytokine is IFN-alpha, which is induced to its maximum level approximately 11-15 h after addition of Sendai virus. The amount of IFN-alpha induced at 15 h after Sendai virus treatment is more than 16-fold higher than those of MIP-1alpha, MIP-1beta, and RANTES. IFN-alpha is also induced more than 60-fold higher than TNF-alpha and IL-8. The amount of IL-6 induced is approximately 400-fold less than IFN-alpha. Limited amounts of other cytokines such as IL-1alpha, IL-1beta, macrophage colony-stimulating factor, TNF-beta, and IFN-gamma are also induced in Sendai virus-treated hPBL. No measurable amount of granulocyte-macrophage colony-stimulating factor, granulocyte colony-stimulating factor, leukemia inhibitory factor, IL-2, IL-3, IL-4, IL-5, IL-7, IL-10, IL-11, or IL-12 was induced in the supernatant of Sendai virus-treated hPBL.
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PMID:Cytokines induced by Sendai virus in human peripheral blood leukocytes. 869 16

Induction of hepatic nitric oxide synthase (NOS) by tumor necrosis factor-alpha (TNF alpha), interleukin-1 beta (IL-1 beta), interferon-gamma (IFN gamma), interleukin-6 (IL-6), and lipopolysaccharide was assessed as activity and immunoreactive protein. Hepatic NOS activity was cytosolic and had cofactor requirements consistent with inducible nitric oxide synthase (NOS2). NOS induction by TNF alpha was dose dependent from concentrations of 0.06 to 60 nM and was increased 2-3-fold by IFN gamma. NOS induction was reflective of total TNF alpha binding to hepatocyte receptors. Hepatocyte TNF alpha binding fit a biphasic curve with high affinity (K(d) = 1.4 nM, Bmax = 3157 sites) and low affinity (K(d) = 157 nM, Bmax = 204,948 sites) elements. NOS2 activity was induced by lipopolysaccharide, IL-1 beta, TNF alpha, and IFN gamma but not by IL-6. All cytokine stimuli were inhibited by antioxidants. Oxygen radical generation was directly measured as dichlorofluoroscein fluorescence in isolated mitochondria. Mitochondria from TNF alpha-treated hepatocytes generated more oxygen radicals than did controls. Antioxidants reduced mitochondrial generation of oxygen radicals. Activation of the transcription factor nuclear factor-kappa B by TNF alpha, IFN gamma, and IL-1 beta was assessed by gel shift analysis. Cytokine treatment increased nuclear factor-kappa B binding, and the addition of antioxidants or rotenone inhibited cytokine activation. Taken together, these data suggest that oxygen radicals, possibly generated by mitochondria, play a major role in NOS2 induction by cytokines.
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PMID:Characterization of hepatic nitric oxide synthase: identification as the cytokine-inducible form primarily regulated by oxidants. 870 Jan 34

Serum levels of cytokines and in vitro cytokine production by lymph node mononuclear cells (LNMC) were studied in four patients with angio-immunoblastic lymphadenopathy with dysproteinemia (AILD) or AILD-type T cell lymphoma. An increased level of serum interleukin-6 (IL-6) was detected on initial diagnosis in both of two patients examined. Spontaneous production of IL-6 by LNMC was detected in all four patients studied. Immunosuppressive therapy with cyclosporin A (CsA) was attempted in a 68-year-old man, who was refractory to intensive combination chemotherapy. The increased level of IL-6 in this patient decreased to normal within 3 weeks of CsA administration and the patient became symptom-free. One and a half months later, the IL-6 level gradually increased along with clinical exacerbation. We also measured serum levels of IL-1 alpha, IL-2, IL-4, IFN-alpha, gamma and TNF-alpha in parallel with IL-6, but these factors were only sporadically detected. IL-6 production by LNMC was stimulated by IL-2 but inhibited by CsA. These observations suggest that IL-6 is one of the important cytokines to be involved in the pathophysiology of AILD and CsA is a useful reagent for relieving symptoms.
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PMID:Increased levels of interleukin-6 (IL-6) in serum and spontaneous in vitro production of IL-6 by lymph node mononuclear cells of patients with angio-immunoblastic lymphadenopathy with dysproteinemia (AILD), and clinical effectiveness of cyclosporin A. 875 70

Keratin K17, the myoepithelial keratin, is expressed in psoriasis but is not present in healthy skin. Psoriasis is associated with production of gamma interferon (IFN gamma), which induces the expression of keratin K17 by activating transcription factor STAT1. Our hypothesis states that the induction of K17 is specific for the inflammatory reactions associated with high levels of IFN gamma and activation of STAT1. One of the corollaries of the hypothesis is that the STAT1-activating cytokines should induce the expression of keratin K17, whereas those cytokines that work through other mechanisms should not. Furthermore, because the STAT activation pathway is dependent upon protein phosphorylation events, phosphorylation inhibitors should attenuate the induction of keratin K17, whereas protein phosphatase inhibitors should augment it. To test this hypothesis, we analyzed lesional samples of inflammatory diseases using immunofluorescence, transfected keratinocytes with K17 gene promoter DNAs in the presence of various cytokines, and followed nuclear translocation of STAT1 in keratinocytes using specific antibodies. Confirming the hypothesis, we found that K17 is induced in psoriasis and dermatitis caused by delayed type hypersensitivity, which are associated with high levels of IFN gamma, but not in samples of atopic dermatitis, which is not. Two cytokines, interleukin-6 and leukemia inhibitory factor, which can induce phosphorylation of STAT1, can also induce K17 expression, whereas interleukin-3, interleukin-4, interleukin-10, and granulocyte macrophage colony stimulating factor have no effect on K17 expression. As expected, staurosporine and genistein inhibited, whereas okadaic acid augmented, the induction of K17 by IFN gamma. Our data indicate that in inflammatory skin diseases, lymphocytes, through the cytokines they produce, differently regulate not only each other, but also keratin gene expression in epidermis one of their target tissues.
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PMID:Regulation of epidermal expression of keratin K17 in inflammatory skin diseases. 882 63

The release of monokines such as Tumor Necrosis Factor a (TNF alpha), Interleukin-1 beta (IL-1 beta) and Interleukin-6 (IL-6) by activated monocytes/macrophages is an important step in the immune as well as in the inflammatory response. In this study the production of TNF alpha, IL-1 beta and IL-6 by human monocytes (HM) and peripheral blood mononuclear cells (PBMC) was evaluated after HHV-6 infection. Our results demonstrate that HHV-6 can selectively regulate monokine synthesis, in a time-dependent manner. Moreover, we observed a different response closely related to the cellular population (HM or PBMC) examined. The hypothesis we evaluated was that IFN gamma is an important factor triggering the activation of HHV-6 infected human monocytes, to release monokines.
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PMID:Role of IFN gamma on TNF alpha, IL-1 beta and IL-6 release during HHV-6 infection. 884 Oct 33

The influence of cytokines on intracellular calcium concentration ([Ca2+]i) and the production of prostacyclin (prostaglandin l2; PGI2) by cultured human umbilical vein endothelial cells (HUVEC) were examined. HUVEC were incubated for 24 h in media containing interleukin-1 beta (IL-1 beta), tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN gamma), or interleukin-6 (IL-6), and thrombin-stimulated increases in [Ca2+]i and PGI2 production were then examined. Thrombin-stimulated PGI2 production by HUVEC pretreated with 10 U/mL of IL-1 beta or 200 U/mL of TNF-alpha for 24 h was potentiated, while increases in [Ca2+]i were suppressed. In contrast, HUVEC pretreated with 5000 U/mL of IFN-gamma for 24 h had both enhanced PGI2 production and increases in [Ca2+]i. IL-6 affected neither PGI2 production nor [Ca2+]i in HUVEC stimulated with thrombin. The burst increase in thrombin-stimulated PGI2 production by HUVEC pretreated with cytokines did not correlate with the increase in [Ca2+]i. Cytokines have been reported to induce enzymes involved in the arachidonic acid cascade, such as phospholipase A2 (PLA2) and cyclooxygenase-2 (COX-2). Therefore, the increase in [Ca2+]i does not appear to be as important for thrombin-stimulated PGI2 production as does the induction of these enzymes by cytokines.
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PMID:Effect of cytokines on thrombin-stimulated increases in intracellular calcium and PGI2 production by cultured human umbilical vein endothelial cells. 884 24

Interferon-alpha combined with retinoid or PUVA is used for the treatment of cutaneous T-cell lymphoma. Anti-IFN-alpha antibodies (IFN ab) occur regularly during IFN-alpha treatment. We investigated the incidence of neutralizing and binding IFN ab and analysed their relationship with clinical and immunological parameters. A group of 17 CTCL patients were treated with IFN alpha-2a three times weekly subcutaneously at a dose of 3 Mill. I.U. combined either with retinoid (acitretin, Neotigason; 0.5 mg/kg bodyweight) daily or with 5-methoxypsoralen (1.2 mg/kg bodyweight) plus UVA radiation three times weekly. Prior to and during treatment we monitored stage, skin involvement by a tumour burden index, serum levels of beta 2-microglobulin, neopterin, binding and neutralizing IFN ab, Interleukin-6 (IL-6), soluble IL-2 receptors (sIL-2r) and the CD4/CD8 ratio of peripheral blood mononuclear cells. We observed two complete, two partial and six minor responses, four patients with stable disease and three patients with progressive disease. Of the 17 patients, 7 developed binding IFN ab, but only 2 had neutralizing IFN ab which were associated with high titres of binding IFN ab. IFN ab formation was more frequent in patients with normal CD4/CD8 ratios and a high tumour burden index and showed a trend to be more frequent in PUVA-cotreated patients than in retinoid-cotreated patients. Responses were more frequently seen in IFN ab-negative patients. IFN ab developed in patients treated with PUVA or retinoid combined with IFN. Binding as well as neutralizing IFN ab may have an impact on the treatment success in CTCL patients.
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PMID:Incidence and in-vivo relevance of anti-interferon antibodies during treatment of low-grade cutaneous T-cell lymphomas with interferon alpha-2a combined with acitretin or PUVA. 887 50

In vitro infection of freshly isolated human peripheral blood mononuclear cells (HPBMC) with Chlamydia pneumoniae was found to induce a production of tumour necrosis factor alpha (TNF-alpha), interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6) and interferon alpha (IFN-alpha). The secretion was dependent on the amount of infecting chlamydiae and most of it occurred during the first 12 to 24 h. Lipopolysaccharide (LPS) of Salmonella minnesota Rechemotype, used as a positive control for HPBMC activation, induced a release of TNF-alpha, IL-1 beta and IL-6, but not of IFN-alpha, similar to the effect of C. pneumoniae. Viable chlamydiae could not be recovered from HPBMCs infected immediately after their isolation, whereas HPBMCs which were cultured in vitro for 3 to 9 days before infection were able to maintain the growth of C. pneumoniae. Growth inside HPBMCs as well as induction of cytokine response may have a role in the pathogenesis of C. pneumoniae infection.
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PMID:Growth of Chlamydia pneumoniae in cultured human peripheral blood mononuclear cells and induction of a cytokine response. 887 18


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