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)

Development of Kaposi's sarcoma (KS) after glucocorticoid therapy has been observed in a variety of clinical states including human immunodeficiency virus-1 infection and recent in vitro studies provided evidence for a direct stimulation effect of glucocorticoid hormones on KS cell proliferation. The importance of glucocorticoids in KS pathogenesis is further highlighted by the finding that glucocorticoids synergize with cytokines to promote acquired immune deficiency syndrome (AIDS)-associated KS (AIDS-KS) growth. Furthermore, cytokine effects were abrogated by the glucocorticoid antagonist RU-486. As glucocorticoid action is mediated through activation of their intracellular cognate receptors, we hypothesized that enhanced responsiveness of AIDS-KS cells to glucocorticoids may be due to elevated glucocorticoid receptor (GR) content. Indeed, high expression of GRs in AIDS-KS tumor biopsies was detected both at the level of mRNA and protein. Quantitative measurements of GRs in these specimens by a sensitive immunoassay showed that GR content was significantly elevated in the tumor tissue (4663 fmol/mg protein) compared with the uninvolved skin of the same patients (2777 fmol/mg protein), both of which were markedly above the normal skin of healthy donors (893 fmol/mg protein). Immunocytochemical analysis confirmed the presence of GRs in the cytoplasm and the nucleus of KS cells. Interestingly, four major KS cytokines, namely interleukin-1beta, interleukin-6, tumor necrosis factor-alpha, and oncostatin M, all of which are known autocrine growth factors for AIDS-KS cells, significantly increased the expression of functional GRs in cultured AIDS-KS cells. The latter result may explain, at least in part, the synergistic effect of glucocorticoid and oncostatin M on AIDS-KS cell proliferation. Thus, the high levels of GR expression in AIDS-KS and the up-regulation of GRs by KS-growth-promoting factors may confer enhanced and sustained sensitivity to the stimulatory effects of glucocorticoids. The data presented also provide molecular bases for therapeutic interventions targeting GRs in this disease.
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PMID:Expression and cytokine regulation of glucocorticoid receptors in Kaposi's sarcoma. 866 84

Cancer-induced cachexia is a common manifestation observed in patients with malignancies. Elevated levels of circulating glucocorticoids and interleukin-6 (IL-6) have been observed in cancer patients with cachexia and are implicated as major mediators in this process. The purpose of this study was to investigate the role of circulating glucocorticoid levels as primary mediators in cancer-induced cachexia. We evaluated whether inhibition of glucocorticoids with the receptor antagonist RU-486 could abrogate the detrimental wasting of muscle and adipose tissues seen in a well-characterized murine tumor-induced cachexia model. Mice (12/group) were randomized to control, tumor-bearing, control + vehicle, or tumor-bearing + glucocorticoid receptor antagonist groups. Circulating serum glucocorticoid and IL-6 levels were measured in addition to multiple body composition parameters, such as total body weight, lean body mass, and adipose content. The results of this study indicate a significant physiological alteration in the tumor-bearing host that causes severe and detrimental changes in body composition parameters. Regression analysis demonstrated a significant correlation between increased circulating glucocorticoid levels and alterations in body composition parameters. These observed defects were not abrogated with the administration of a glucocorticoid receptor antagonist. We therefore conclude that the untoward effects of tumor-induced cachexia are not mediated primarily by the peripheral effects of high circulating glucocorticoid levels but may involve a complex interaction with IL-6.
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PMID:Glucocorticoid blockade does not abrogate tumor-induced cachexia. 1069 76

Metallothionein I (MT-I) and MT-II have been implicated in the protection of cells against reactive oxygen species (ROS), heavy metals, and a variety of pathological and environmental stressors. Here, we show a robust increase in MT-I/MT-II mRNA level and MT proteins in the livers and lungs of C57BL/6 mice exposed to the influenza A/PR8 virus that infects the upper respiratory tract and lungs. Interleukin-6 (IL-6) had a pronounced effect on the induction of these genes in the liver but not the lung. Treatment of the animals with RU-486, a glucocorticoid receptor antagonist, inhibited induction of MT-I/MT-II in both liver and lung, revealing a direct role of glucocorticoid that is increased upon infection in this induction process. In vivo genomic footprinting (IVGF) analysis demonstrated involvement of almost all metal response elements, major late transcription factor/antioxidant response element (MLTF/ARE), the STAT3 binding site on the MT-I upstream promoter, and the glucocorticoid responsive element (GRE1), located upstream of the MT-II gene, in the induction process in the liver and lung. In the lung, inducible footprinting was also identified at a unique gamma interferon (IFN-gamma) response element (gamma-IRE) and at Sp1 sites. The mobility shift analysis showed activation of STAT3 and the glucocorticoid receptor in the liver and lung nuclear extracts, which was consistent with the IVGF data. Analysis of the newly synthesized mRNA for cytokines in the infected lung by real-time PCR showed a robust increase in the levels of IL-10 and IFN-gamma mRNA that can activate STAT3 and STAT1, respectively. A STAT1-containing complex that binds to the gamma-IRE in vitro was activated in the infected lung. No major change in MLTF/ARE DNA binding activity in the liver and lung occurred after infection. These results have demonstrated that MT-I and MT-II can be induced robustly in the liver and lung following experimental influenza virus infection by overlapping but distinct molecular mechanisms.
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PMID:Influenza virus infection induces metallothionein gene expression in the mouse liver and lung by overlapping but distinct molecular mechanisms. 1171 67

Fever is the most common manifestation of the innate immune response to invading pathogens. Animals prevented from developing fever have increased morbidity and mortality to infection. We now show that early life events can program this innate immune response, in that rats that have been challenged neonatally with the immune stimulant lipopolysaccharide (LPS) have both suppressed febrile responses to LPS as adults and significantly reduced nuclear factor (NF)-kappaB activation in peripheral immune organs. This was associated with reduced levels of proinflammatory cytokines tumor necrosis factor (TNF)-alpha, and interleukin-6 (IL-6) in the plasma after adult LPS challenge, compared with animals that have received saline neonatally. In contrast, adult LPS challenge elicited higher corticosterone levels in the animals that had been treated neonatally with LPS. When this increased corticosterone response was negated by adrenalectomy or by administration of the glucocorticoid receptor antagonist RU-486, both the cytokine and febrile responses were normalized. This study indicates that the innate immune response can be programmed by a neonatal LPS challenge, whereby an amplified hypothalamic-pituitary-adrenal response causes reduced cytokine synthesis and an attenuated febrile response to an adult immune challenge. In light of the importance of fever in the host defense response, these alterations may have deleterious consequences on an individual's ability to combat disease later in life.
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PMID:Early life immune challenge alters innate immune responses to lipopolysaccharide: implications for host defense as adults. 1597 2

Combined treatment with dexamethasone and oncostatin M (DEX/OSM) or interleukin-6 (DEX/IL-6) resulted in the appearance of numerous large vacuoles in human fetal liver (HFL) cells and showed synergistic effects on the formation of vacuoles. The number of vacuoles formed by DEX, DEX/OSM, or DEX/IL-6 was significantly suppressed by RU-486, a glucocorticoid receptor antagonist. On the other hand, the size of vacuoles formed by OSM, IL-6, DEX/OSM, or DEX/IL-6 was significantly decreased to about 65% by madindoline A (MDL-A), which is a non-peptide antagonist of gp130 and an inhibitor of cytokines, such as IL-6, mediated by gp130 homodimerization, while RU-486 did not affect the size of vacuoles. Expression of IL-6 mRNA in HFL cells was markedly induced by OSM. Expression of IL-6R mRNA was induced by DEX. These results indicate that DEX contributes to the formation of vacuoles through glucocorticoid receptors and that OSM and IL-6 contribute to enlargement of these vacuoles.
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PMID:Role of dexamethasone and oncostatin M on the formation of vacuoles in human fetal liver cells. 1918 77

11beta-Hydroxysteroid dehydrogenase 1 (11beta-HSD1) is primarily responsible for intracellular biosynthesis of active glucocorticoid, and its tissue-specific dysregulation has been implicated in the development of metabolic syndromes. We have developed a cell-based assay for measuring 11beta-HSD1 activities using murine skeletal muscle cell line C2C12. We found that the messenger RNA (mRNA) expression of 11beta-HSD1 increased on differentiation with enhanced enzyme activity as determined by homogeneous time-resolved fluorescence (HTRF) assay. Carbenoxolone, a well-known 11beta-HSD1 inhibitor, exhibited an IC(50) value similar to that in in vitro microsomal assay (IC(50) = 0.3 microM). Unlike in vitro microsomal assay, cosubstrate NADPH was not required in the cell-based assay, indicating that viable cells might provide a sufficient amount of endogenous NADPH to catalyze the enzymatic conversion of inactive cortisone to active cortisol. Treatment of C2C12 myotubes with cortisone concentration dependently transactivated and transrepressed glutamine synthase and interleukin-6, respectively, which were abrogated by carbenoxolone or RU-486 (mifepristone), a glucocorticoid receptor antagonist. Accordingly, a newly designed cell-based assay using differentiated skeletal muscle cells would be useful for high-throughput screening of 11beta-HSD1 inhibitors as well as for understanding the molecular mechanisms of glucocorticoid action.
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PMID:Cell-based assay for screening 11beta-hydroxysteroid dehydrogenase 1 inhibitors. 1949 89

Clinical studies have demonstrated an impairment of glucocorticoid receptor (GR)-mediated negative feedback on the hypothalamic-pituitary-adrenal (HPA) axis in patients with major depression (GR resistance), and its resolution by antidepressant treatment. Recently, we showed that this impairment is indeed due to a dysfunction of GR in depressed patients (Carvalho et al., 2009), and that the ability of the antidepressant clomipramine to decrease GR function in peripheral blood cells is impaired in patients with major depression who are clinically resistant to treatment (Carvalho et al. 2008). To further investigate the effect of antidepressants on GR function in humans, we have compared the effect of the antidepressants clomipramine, amytriptiline, sertraline, paroxetine and venlafaxine, and of the antipsychotics, haloperidol and risperidone, on GR function in peripheral blood cells from healthy volunteers (n=33). GR function was measured by glucocorticoid inhibition of lypopolysaccharide (LPS)-stimulated interleukin-6 (IL-6) levels. Compared to vehicle-treated cells, all antidepressants inhibited dexamethasone (DEX, 10-100nM) inhibition of LPS-stimulated IL-6 levels (p values ranging from 0.007 to 0.1). This effect was specific to antidepressants, as antipsychotics had no effect on DEX-inhibition of LPS-stimulated IL-6 levels. The phosphodiesterase (PDE) type 4 inhibitor, rolipram, potentiated the effect of antidepressants on GR function, while the GR antagonist, RU-486, inhibited the effect of antidepressants on GR function. These findings indicate that the effect of antidepressants on GR function are specific for this class of psychotropic drugs, and involve second messenger pathways relevant to GR function and inflammation. Furthermore, it also points towards a possible mechanism by which one maybe able to overcome treatment-resistant depression. Research in this field will lead to new insights into the pathophysiology and treatment of affective disorders.
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PMID:Antidepressants, but not antipsychotics, modulate GR function in human whole blood: an insight into molecular mechanisms. 2023 Oct 81