TNF-a tumor necrosis factor

Tumor Necrosis Factor a TNF Receptor Superfamily Cytokines Inflammation... 

Inflammatory cytokines have been implicated in the pathophysiology of HF.9 Several proinflammatory (e.g., tumor necrosis factor-a [TNF-a], interleukin-1, interleukin-6, and interferon-y) and anti-inflammatory cytokines (e.g., interleukin-10) are overexpressed in the failing heart. The most is known about TNF-a, a pleiotrophic cytokine that acts as a negative inotrope, stimulates cardiac cell apoptosis, uncouples 3-adrenergic receptors from adenylyl cyclase, and is related to cardiac cachexia. The exact role of cytokines and inflammation in HF pathophysiology continues to be studied. 

Eosinophils may be increased in some patients, particularly during exacerbations. Activated inflammatory cells release a variety of mediators, most notably leukotriene B4, interleukin-8, and tumor necrosis factor-a (TNF-a). Various proteinases, such as elastase, cathepsin G, and proteinase-3, are secreted by activated neutrophils. These mediators and proteinases are capable of sustaining inflammation and damaging lung structures. 

Etanercept is a fully human dimeric fusion protein composed of human TNF-a p75 receptor fused to the Fc portion of human IgG 1.41 It acts as a tumor necrosis factor-a (TNF-a) inhibitor by binding to and inactivating TNF-a, thus preventing interactions with its cell surface receptors.41 This agent is useful for chronic moderate to severe plaque psoriasis and for psoriatic... 

Compounds 674-676 are potent orally bioavailable inhibitors of tumor necrosis factor-a (TNF-a) production <2004BML4267, 2004JME2724>. 

Once T cells are activated, they migrate from lymph nodes and the bloodstream into skin and secrete various cytokines (e.g., interferon % interleukin 2 [IL-2]) that induce the pathologic changes of psoriasis. Local keratinocytes and neutrophils are induced to produce other cytokines, such as tumor necrosis factor-a (TNF-a), IL-8, and others. 

The major types of drug therapy used in IBD include aminosalicylates, glucocorticoids, immunosuppressive agents (azathioprine, mercaptopu-rine, cyclosporine, and methotrexate), antimicrobials (metronidazole and ciprofloxacin), and agents to inhibit tumor necrosis factor-a (TNF-a) (anti-TNF-a antibodies). 

Sepsis involves a complex interaction of proinflammatory (e.g., tumor necrosis factor-a [TNF-a] interleukin [IL]-1, IL-6) and antiinflammatory mediators (e.g., IL-1 receptor antagonist, IL-4, and IL-10). IL-8, plateletactivating factor, and a variety of prostaglandins, leukotrienes, and thromboxanes are also important. 

Tumor necrosis factor a (TNF-a) is a multifunctional cytokine produced by activated monocytes-macrophages. TNF-a is one of the most potent osteoclastogenic cytokines produced in inflammation, and, in addition, TNF-a induces IL-1 synthesis. Like the other known stimulators of bone resorption, it acts through osteoblastic cells however, it has been demonstrated that TNF-a is able to induce osteoclast formation from stromal-depleted macrophages, with potency similar to that of RANKL (Kobayashi et al. 2000). TNF-a is able to induce bone resorption in vitro (Thomson et al. 1987) as well as in vivo (Koning et al. 1988). Osteoclasts induced by TNF-a have the capacity to form resorption pits on dentine slices only in the presence of IL-la. TNF-a, together with IL-1, plays an important role in bone resorption in inflammatory diseases (Kobayashi et al. 2000). Inhibition of TNF by TNF binding protein (TNFbp) completely prevents bone loss and osteoclast formation (Kimble et al. 1997). 

Tumor necrosis factor-a (TNF-a) is a critical mediator of inflammation in autoimmune diseases like Crohn s disease and rheumatoid arthritis. Infliximab binds TNF-a and prevents its binding to the TNF receptor for treatment of these diseases. 

Anti-arthritic effect. Oral administration of AJA, a cannabinoid acid devoid of psychoactivity, reduced joint tissue damage in rats with adjuvant arthritis. Peripheral blood monocytes (PBM) and synovial fluid monocytes (SFM) were isolated from healthy subjects and patients with inflammatory arthritis, respectively, treated with AJA (0-30 mM) in vitro, and then stimulated with lipopolysaccharide. Cells were harvested for messenger RNA (mRNA), and supernatants were collected for cytokine assay. Addition of AJA to PBM and SFM in vitro reduced both steady-state levels of interleukin-ly (IL-ly) mRNA and secretion of IL-ly in a concentration-dependent manner. Suppression was maximal (50.4%) at 10 mM AJA (p < 0.05 vs untreated controls, n = 7). AJA did not influence tumor necrosis factor-a (TNF-a) gene expression in or secretion from PBM . 

Extracts of leaves of Combretum quadrangulare showed promising hepatoprotective effect on D-GalN or tumor necrosis factor-a (TNF-a)-induced cell death in primary cultured mouse hepatocytes. The hepatoprotective effect of C-glycosylflavones from C. quadrangulare was determined by evaluation of the serum enzyme level in comparison with the o-GalN or TNF-a treated control. At the concentration of 200 pg/ml, orientin and isoscoparin possessed an inhibitory effect on TNF-a-induced cell death of about 20%, while vitexin at 100 pg/ml produces a 95%i inhibitory effect. 

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