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)

Lipopolysaccharide (LPS) and inflammatory cytokines cause activation of sphingomyelinases (SMases) and subsequent hydrolysis of sphingomyelin (SM) to produce a lipid messenger ceramide. The design of SMase inhibitors may offer new therapies for the treatment of LPS- and cytokine-related inflammatory bowel disease. We synthesized a series of difluoromethylene analogues of SM (SMAs). We report here the effects of the most potent SMase inhibitor, SMA-7, on the LPS-mediated release of tumour necrosis factor-alpha, interleukin-1beta and interleukin-6 from THP-1 macrophages and the pathology of dextran sulphate sodium (DSS)-induced colitis in mice. SMA-7 suppressed the LPS-induced cytokine release and nuclear factor-kappaB activation. LPS stimulation caused a four-fold increase in acid SMase activation, but little increase in neutral SMase activity. The presence of 10 microm SMA-7 caused acid SMase to remain at the control levels and reduced the formation of ceramide. HT-29 cells had significantly decreased cell viability when incubated with media from LPS-stimulated THP-1 macrophages. However, incubating the colon cells in media from both SMA-7 and LPS-treated macrophages caused little decrease in viability, suggesting that ceramide has a role in the LPS-stimulated signalling that releases cytotoxic factors against colon cells. Oral administration of SMA-7 to mice with 2% DSS in the drinking water, for 10 or 21 consecutive days, reduced significantly the cytokine levels in the colon and the severity of colonic injury. These findings suggest a central role for acid SMase/ceramide signalling in the pathology of DSS-induced colitis in mice, indicating a possible preventive or therapeutic role for SMase inhibitor in inflammatory bowel disease.
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PMID:Acid sphingomyelinase inhibition suppresses lipopolysaccharide-mediated release of inflammatory cytokines from macrophages and protects against disease pathology in dextran sulphate sodium-induced colitis in mice. 1745 62

Interleukin-6 (IL-6) is a pleiotropic cytokine with central roles in immune and inflammatory reactions. IL-6 first binds to the IL-6 receptor (IL-6R), this complex then associates with gp130, inducing dimerization and the initiation of signaling through signal transducer and activator of transcription-3 (STAT3). Notably, the combination of soluble IL-6 receptor (sIL-6R) and IL-6 stimulates cells that only express gp130 and not IL-6R, a process known as trans-signaling. In contrast, soluble gpl30 (sgp130) serves as a natural inhibitor of trans-signaling. Accumulated evidence strongly supports the hypothesis that the development and perpetuation of inflammatory bowel disease (IBD) relies on IL-6-mediated STAT3 activation on mucosal T-cells. This review looks at therapeutic strategies targeting the IL-6/STAT3 pathway in patients with IBD, including strategies involving the anti-IL-6 receptor antibody and soluble gp130Fc.
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PMID:Therapeutic strategies for targeting the IL-6/STAT3 cytokine signaling pathway in inflammatory bowel disease. 1797 38

Hepatic cytochrome P450 (P450) enzymes are down-regulated during inflammation. In this study, an animal model of inflammatory bowel disease was subjected to characterization of hepatic P450 expression under inflammatory conditions. Rats were treated intracolonically with 100 mg/kg trinitrobenzene sulfonic acid (TNBS) dissolved in 30% ethanol, and homogenates of colonic mucosa and hepatic microsomes of the rats were prepared. The colitis was accompanied by appearance of higher levels of portal endotoxin, interleukin-6, and nitric oxide metabolites and decreases in contents and activities for hepatic CYP3A2, CYP2C11, and, to a lesser extent, CYP1A2 and CYP2E1. Nimesulide, a preferential COX-2 inhibitor, protected rats with TNBS-induced colitis (TNBS-colitis) against the down-regulation of hepatic CYP3A2. Polymyxin B, which neutralizes endotoxin, curcumin, which has anti-inflammatory properties, and gadolinium chloride, which inactivates macrophages, attenuated the down-regulation of CYP3A2. Similar effects were observed in other P450s such as CYP2C11, but the agents were less effective in attenuating the down-regulation. Our data suggest that endogenous substances leaked from damaged colon in the rats with TNBS-colitis activate Kupffer cells, leading to down-regulation of hepatic P450s with differential susceptibility to the inflammatory stimuli. The colitis model, instead of exogenous administration of lipopolysaccharide or cytokines, could be applied to the study on mechanisms for altered hepatic P450 expression and other liver functions under mild inflammatory conditions.
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PMID:Down-regulation of hepatic cytochrome P450 enzymes in rats with trinitrobenzene sulfonic acid-induced colitis. 1807 64

The etiology of inflammatory bowel disease (IBD) is not completely understood, thus current therapies have been empirical and directed at treating symptoms rather than addressing the cause. In IBD, the overexpression of proinflammatory cytokines, such as tumor necrosis factor-alpha, interleukin-1beta, interleukin-6, leads to a persistent intestinal inflammatory response that damages the intestinal mucosa. Recent advances in pharmacologic therapies that target specific cytokines, chemokines, and adhesion molecules have proved successful in alleviating symptoms for some patients. There are 2 selective adsorption apheresis devices that remove leukocytes from whole blood, which are currently available in Japan and Europe-the Cellsorba leukocytapheresis column and the Adacolumn adsorptive extracorporeal granulocyte/monocyte apheresis device. The purported mechanisms of action of these devices have been extensively reviewed and are believed to exert an immunomodulatory and/or anti-inflammatory effect on patients with systemic inflammatory disease. The clinical trials presented here indicate that selective leukocyte apheresis effectively removes activated granulocytes and monocytes/macrophages from peripheral blood while maintaining an excellent safety profile. Despite these findings, large controlled trials of selective leukocyte apheresis in the treatment of IBD are needed to determine the true efficacy of this approach.
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PMID:Selective leukocyte apheresis for the treatment of inflammatory bowel disease. 1809 Jan 55

Apart from genetic and environmental factors, the mucosal immune system of the gut plays a central role in the pathogenesis of inflammatory bowel disease (IBD). In the healthy gut, the mucosal immune system ensures the balance between pro- and anti-inflammatory mediators and thereby allows an effective defence against luminal pathogens but at the same time prevents an overwhelming immune reaction directed against the huge amount of harmless luminal antigens (for example, components of food or nonpathological bacteria). In both entities of IBD (Crohn's disease and ulcerative colitis) this immunological balance is severely impaired and shifted towards the pro-inflammatory side. The chronic mucosal inflammation in IBD is caused by hyperactivation of effector immune cells, which produce high levels of pro-inflammatory cytokines like tumour necrosis factor-alpha, interleukin-6 and interferon-gamma, resulting in colonic tissue damage. The nuclear transcription factor kappaB (NF-kappaB) was identified as one of the key regulators in this immunological setting. Its activation is markedly induced in IBD patients and through its ability to promote the expression of various pro-inflammatory genes, NF-kappaB strongly influences the course of mucosal inflammation. Considering the different cell-type specific effects which are mediated by NF-kappaB, this review aims at describing the complex role of NF-kappaB in IBD and discusses existing pharmacological attempts to block the activation of NF-kappaB to develop new therapeutic strategies in IBD.
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PMID:NF-kappaB in inflammatory bowel disease. 1847 58

During inflammation, lower molecular weight fragments of hyaluronan accumulate, and this is known to be inflammatory and immune-stimulatory. In diseases such as inflammatory bowel disease, inflammatory cells bind to hyaluronan; however, the cellular response and molecular mechanism of hyaluronan-hyaluronan receptor interactions in mononuclear cells are not well understood. The expression of hyaluronan receptors in peripheral blood mononuclear cells (PBMC) was examined. PBMC were stimulated with lower and higher molecular weight hyaluronan (molecular weight 100-150 kDa and 2700 kDa) and the induction of proinflammatory cytokines (interleukin-6 (IL-6) and monocyte chemoattractant protein (MCP-1)) was compared by enzyme-linked immunoabsorbant assay (ELISA). Cells were coincubated with various signaling pathway inhibitors. In addition, neutralizing antibodies against CD44 and TLR4 were added and the effects on PBMC were investigated. Finally, mononuclear cells from CD44-null and toll-like receptor 4 (TLR4) mutant mice were both stimulated with lower molecular weight hyaluronan. Among the hyaluronan receptors, TLR4 and CD44 were markedly expressed on PBMC. Hyaluronan-stimulated PBMC enhanced the attachment to the extracellular matrix. Lower molecular weight hyaluronan induced IL-6 and MCP-1 production in PBMC, but high-molecular-weight hyaluronan did not induce IL-6 and MCP-1 production. An anti-CD44 antibody attenuated the induction of both IL-6 and MCP-1 in lower molecular weight hyaluronan-stimulated PBMC. In both TLR4 mutant and CD44-null mice, the induction of IL-6 by lower molecular weight hyaluronan stimulation was decreased. SB203580 completely abolished IL-6 production in both TLR4 mutant and CD44-null mononuclear cells, while PD98059 abolished IL-6 production in CD44-null mononuclear cells. Hyaluronan receptors, CD44 and TLR4, play distinct roles in cytokine induction in hyaluronan-stimulated mononuclear cells.
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PMID:Hyaluronan receptors involved in cytokine induction in monocytes. 1885 67

Hyaluronan (HA) occurs in the body as a large, hydrating, space-filling, carbohydrate polymer in the extracellular matrix; it has both anti-angiogenic and immunosuppressive properties. Cleavage of HA results in the generation of variably sized fragments that stimulate multiple angiogenic and inflammatory responses in a size-specific manner. In this study, we report that platelets, as well as their megakaryocyte precursors, are unusual among somatic cells in that they contain only hyaluronidase 2 (HYAL2) but not HYAL1. Platelet HYAL2 is sufficient to cleave HA into fragments that are specific for inflammatory and angiogenic signaling; this process occurs in the absence of HYAL1, which is necessary in all other tissues to perform further HA degradation. Platelets can bind to HA, some of which derives from the stressed microvessel endothelial cell surface. Platelet-derived HYAL2 cleaves HA into fragments that stimulate mononuclear leukocytes in the immediate microenvironment to produce proinflammatory cytokines, including interleukin-6 and interleukin-8. Platelets, thus, are not only involved in hemostasis, the earliest step in wound healing, but are also important in the signaling of subsequent inflammatory and angiogenic steps. We hypothesize that aberrations in these sequential steps can promote chronic inflammation, as found in inflammatory bowel disease. The platelet may thus provide an interface between acute and chronic inflammation, wound healing, and their subsequent fibrotic responses.
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PMID:Platelet-derived hyaluronidase 2 cleaves hyaluronan into fragments that trigger monocyte-mediated production of proinflammatory cytokines. 1943 89

Chronic inflammation severely increases the risk for cancer development as seen in patients with inflammatory bowel disease (IBD). Although the exact mechanisms of inflammation-associated tumor development remain to be shown, a role for the adaptive immune system has been implicated in colitis-associated cancer (CAC). In fact, CD4+ effector T cells, which promote chronic inflammation in IBD, create a tumor convenient environment, which can lead to cancer initiation, promotion, and progression. Thereby, the cytokines interleukin-6 and tumor necrosis factor-alpha constitute an important link between inflammation and tumor growth. Furthermore, cytotoxic CD8+ T cells, which usually are protective as part of the host antitumor immune response in sporadic cancer, can contribute to the aggravation of chronic inflammation and thereby support tumor development. In contrast, regulatory T cells, which have been shown to attenuate tumor immunosurveillance, act as potent suppressors of chronic inflammation and thus can have protective effects in CAC. This review discusses the role of the adaptive immune response and especially T cells in the pathogenesis CAC and possible implications for the therapeutic applications.
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PMID:Colitis-associated cancer: the role of T cells in tumor development. 1949 57

The complex pathogenesis of inflammatory bowel disease (IBD) and inflammation induced colon cancer involves a wide range of mediators including cytokines. Recent investigations underline the fundamental role of interleukin-6 (IL-6) signaling in the development and maintenance of IBD and for the progression of this inflammation to colon cancer. The molecular mechanisms of this pathway, the source of the cytokine and the identity of target cells in the intestine are incompletely understood. It is known that the circulating and intestinal levels of IL-6 as well as the soluble IL-6 receptor (sIL-6R) are increased in patients with IBD. Remarkably, mucosal T cells of IBD patients are extremely resistant to apoptosis and a large fraction of these cells express membrane-bound gp130 but not the IL-6R. Increasing evidence suggests that the development and perpetuation of IBD relies on IL-6 synthesized by T-cells and myeloid cells and on increased formation of IL-6/sIL-6R complexes interacting with membrane-bound gp130 on T-cells, a process called IL-6 trans-signaling. Recent investigations suggested a protective role of IL-6 mediated STAT3 signaling in intestinal epithelial cells. Here we review these pro- and anti-inflammatory properties of IL-6 in IBD and inflammation induced colon cancer and we will summarize the consequences of these new results for the prospects of IL-6 targeted therapeutic strategies for the treatment of chronic inflammatory diseases such as IBD.
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PMID:Interleukin-6 trans-signaling and colonic cancer associated with inflammatory bowel disease. 1951 47

Interleukin-6 (IL-6)/signal transducer and activator of transcription 3 (STAT3) signals play key roles in the pathogenesis of inflammatory bowel disease (IBD). We previously described that both intact cells and a cell wall-derived polysaccharide-peptidoglycan complex (PSPG) in a strain of lactobacillus [Lactobacillus casei Shirota (LcS)] inhibited IL-6 production in lipopolysaccharide (LPS)-stimulated lamina propria mononuclear cells (LPMCs) isolated from murine IBD. Diets with LcS improve murine IBD by suppression of IL-6 synthesis in LPMCs. Moreover, LcS supplementation with fermented milk ameliorates disease activity in patients with active ulcerative colitis. Here, we focused on the specific roles of PSPG in LcS concerning their anti-inflammatory actions. PSPG derived from LcS, and no other strain of lactobacilli, inhibited IL-6 production in LPS-stimulated murine IBD LPMCs. Purified PSPG-I from LcS inhibited IL-6 synthesis in LPS-stimulated murine IBD LPMCs through the inhibition of nuclear factor-kappaB. The anti-IL-6 action of LcS PSPG was abrogated by masking with monoclonal anti-PSPG-I. Furthermore, PSPG-I-negative L. casei strains (PSPG-I-negative mutant LcS: LC(DeltaPSPG-I), L. casei ATCC 334) did not inhibit IL-6 production. Finally, we confirmed the effects of PSPG-I on LcS in the models of both IBD and colitis-associated cancer (CAC). In the IBD model, ingestion of LcS improved ileitis and inhibited activation of IL-6/STAT3 signaling, while ingestion of the LC(DeltaPSPG-I) strain did not. In the CAC model, treatment with LcS, but not the LC(DeltaPSPG-I) strain, showed tumour-suppressive effects with an inhibition of IL-6 production in the colonic mucosa. These results suggested that a specific polysaccharide component in an L. casei strain plays a crucial role in its anti-inflammatory actions in chronic intestinal inflammatory disorders.
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PMID:A component of polysaccharide peptidoglycan complex on Lactobacillus induced an improvement of murine model of inflammatory bowel disease and colitis-associated cancer. 1974 Mar 6


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