Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P10145 (IL-8)
 23,849 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Biological effects of human natural tumor necrosis factor-alpha (TNF) on glioblastoma cells in vitro and on glioma patients were investigated. TNF treatment on glioblastoma cells, even at a high dose (256 U/ml), exhibited no remarkable cytocidal activity in MTT assay, but at lower doses significantly inhibited colony forming and DNA synthesis. TNF at a low dose (10 U/ml) stimulated production of prostaglandin E2, Mn-superoxide dismutase, interleukin (IL)-6 and IL-8 by glioblastoma cells. These results indicated that the direct effect of TNF on human glioblastoma cells is rather antiproliferative than cytotoxic and is to modulate their metabolic pathways. In an early Phase I clinical trial, TNF was administered intracranially to six patients bearing glioblastoma. In this trial, the author studied in vivo immunological responses in the cerebrospinal fluid and regional fluid after the regional TNF injections. TNF in these body fluids were detected with a half life of several hours. There occurred a substantial number of leukocyte migration after the TNF administration. Neutrophils appeared first peaking at 8 to 12 hours, and then CD4+CD8-T cells and CD11b+CD13+CD14+ monocytes followed. IL-8 activity in the cerebrospinal fluid simultaneously corresponded to peak of the neutrophil migration. Increases in IL-6, IL-1 beta and prostaglandin E2 levels in the cerebrospinal fluid, regional fluid or both occurred peaking at 8 to 12 hours after TNA infection. Neither IL-2 nor interferons was detected. In conclusion, TNF may act as an antineoplastic agent by its direct cytostatic effects and indirectly through immune modulatory effects.
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PMID:[In vitro and in vivo immunobiological responses of glioblastoma to human natural tumor necrosis factor-alpha]. 142 94

We have previously hypothesized that the pro-inflammatory cytokine TNF alpha has a pivotal role in the pathogenesis of rheumatoid arthritis (RA). It mediates its effects by cross-linking surface p55 TNF receptors (TNF-R), which can be proteolytically cleaved to yield soluble fragments. Upon binding TNF alpha soluble TNF-R (sTNF-R) can inhibit its function. We investigated the enzymatic nature of the proteases involved in TNF-R cleavage, and found that this process is blocked by a synthetic inhibitor of matrix metallo-proteinase activity (MMP), BB-2275. Inhibition of TNF-R cleavage was observed in a number of different cell types, as detected by retention of surface bound TNF receptor and by less sTNF-R released into the cell supernatant. The augmentation of surface TNF-R expression was of biological relevance as TNF alpha-mediated necrosis of human KYM.1D4 rhabdosarcoma cells was enhanced approximately 15-fold in the presence of BB-2275. The addition of BB-2275 to rheumatoid synovial membrane cell cultures totally inhibited MMP activity and also significantly reduced the levels of soluble TNF alpha (P < 0.006), p55 sTNF-R (P < 0.006), and p75 sTNF-R (P < 0.004). Paradoxically, despite the reduction in soluble TNF alpha levels, the production of IL-1 beta, IL-6, and IL-8, cytokines whose production was previously demonstrated to be inhibited by the addition of neutralizing anti-TNF alpha antibody were not down-regulated by BB-2275. These results raise the interesting possibility that a close relationship exits between the enzyme(s) which process membrane-bound TNF alpha, and those involved in surface TNF-R cleavage. Furthermore our observations suggest that hydroxamate inhibitors of MMP activity which block TNF alpha secretion and TNF-R cleavage may not modulate down-stream effects of TNA alpha, and as such suggest that the precise specificity of these compounds will be highly relevant to their clinical efficacy in inflammatory diseases.
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PMID:Paradoxical effects of a synthetic metalloproteinase inhibitor that blocks both p55 and p75 TNF receptor shedding and TNF alpha processing in RA synovial membrane cell cultures. 867 95

Knowledge of the aetiology and pathogenesis of the inflammation in ulcerative colitis and Crohn's disease is still insufficient. It is thought that some antigen is the trigger which induces a chain of immune reactions but the origin of this antigen has not so far been elucidated. In theory, an antigen-presenting cell forms a complex with endotoxin-derived peptides as antigen. T-helper lymphocytes recognize this complex, are activated and start to produce cytokines. For inflammatory bowel diseases (IBD) the most important cytokines identified are interleukin 1 (IL-1), interleukin 2 (IL-2), interleukin 6 (IL-6), interleukin 8 (IL-8), gamma-interferon (G-IFN), and tumor necrosis factor-alpha (TNF-alpha). Inhibition of these cytokines can be achieved by administration of cyclosporine, which inhibits the function of T-helper lymphocytes. Orally, intravenously, and locally administered cyclosporine is able to improve the disease activity in ulcerative colitis and Crohn's disease, but its use is limited because of side-effects. The novel immunosuppressant FK506 has comparable actions to cyclosporine in regulating cytokine production and may even be more effective than cyclosporine. The receptor antagonist of IL-1 (IL-1ra) competitively binds to the IL-1 receptor located on several lymphocytes. Treatment of animals with IL-1ra has been successful and clinical trials using recombinant IL-1ra are underway in IBD. Antibodies against alphaIL-2r have also been used successfully in animal studies. No experience with this substance has been obtained in man. The use of alpha-interferon seems to be effective in some patients with Crohn's disease. CD4 and CD8 molecules on lymphocytes are needed to form the interaction between antigen, antigen-presenting cell, and lymphocytes. Specific monoclonal antibodies against CD4 are successfully used in patients with active ulcerative colitis and Crohn's disease. TNF-alpha shares many of the proinflammatory activities of IL-1. In preliminary studies, especially in patients with Crohn's disease, the effects of the administration of antibodies to TNA-alpha were excellent.
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PMID:Selective immunomodulation in patients with inflammatory bowel disease--future therapy or reality? 881 2