968 resultados para recombinant tumor necrosis factor alpha
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Tumor necrosis factor receptor 1 (TNFR1) and Toll-like receptors (TLRs) regulate immune and inflammatory responses. Here we show that the TNFR1-associated death domain protein (TRADD) is critical in TNFR1, TLR3 and TLR4 signaling. TRADD deficiency abrogated TNF-induced apoptosis, prevented recruitment of the ubiquitin ligase TRAF2 and ubiquitination of the adaptor RIP1 in the TNFR1 signaling complex, and considerably inhibited but did not completely abolish activation of the transcription factor NF-kappaB and mitogen-activated protein kinases 'downstream' of TNFR1. TRIF-dependent cytokine production induced by the synthetic double-stranded RNA poly(I:C) and lipopolysaccharide was lower in TRADD-deficient mice than in wild-type mice. Moreover, TRADD deficiency inhibited poly(I:C)-mediated RIP1 ubiquitination and activation of NF-kappaB and mitogen-activated protein kinase signaling in fibroblasts but not in bone marrow macrophages. Thus, TRADD is an essential component of TNFR1 signaling and has a critical but apparently cell type-specific function in TRIF-dependent TLR responses.
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The pro-inflammatory cytokine TNF-α and the female hormone estrogen have been implicated in the pathophysiology of two common gynecological diseases, endometriosis and endometrial adenocarcinoma. Here we describe a novel capacity of TNF-α to activate ER signaling in endometrial epithelial cells. TNF-α induced luciferase expression in the absence and presence of estradiol and also augmented expression of the estrogen-regulated genes c-fos, GREB1, and progesterone receptor. Furthermore, TNF-α mediated ER transcriptional activity is dependent on the Extracellular Regulated Kinase (ERK) 1/2 pathway. Co-treatment with a pure ER antagonist resulted in an inhibition of this TNF-α-induced ERE luciferase activity and gene expression, demonstrating that this cytokine signals through ERs. Additional investigations confirmed that TNF-α acts specifically via ERα. Taken together, these data provide a rationale for the potential use of inhibitors of TNF-α and estrogen production/activity in combination for the treatment of endometrial pathologies.
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Background: Symptom relief is the traditional treatment goal in Crohn's disease (CD). New goals including mucosal healing and bowel preservation are now achievable with tumor necrosis factor (TNF) antagonists. Infliximab and adalimumab are approved as second-line treatments for severe, active CD. Certolizumab pegol is approved only in the U.S. and Switzerland as second-line treatment for moderate-to-severe, active CD. Data from trials of infliximab suggest that high-risk patients and patients with active inflammation (CRP elevation and/or ileocolonic ulcers) may benefit from earlier use of this drug.
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BACKGROUND: Recombinant tumor necrosis factor-alpha (TNF-alpha) combined to melphalan is clinically administered through isolated limb perfusion (ILP) for regionally advanced soft tissue sarcomas of the limbs. In preclinical studies, wild-type p53 gene is involved in the regulation of cytotoxic action of TNF-alpha and loss of p53 function contributes to the resistance of tumour cells to TNF-alpha. The relationship between p53 status and response to TNF-alpha and melphalan in patients undergoing ILP is unknown. PATIENTS AND METHODS: We studied 110 cases of unresectable limbs sarcomas treated by ILP. Immunohistochemistry was carried out using DO7mAb, which reacts with an antigenic determinant from the N-terminal region of both the wild-type and mutant forms of the p53 protein, and PAb1620mAb, which reacts with the 1620 epitope characteristic of the wild-type native conformation of the p53 protein. The immunohistochemistry data were then correlated with various clinical parameters. RESULTS: P53DO7 was found expressed at high levels in 28 patients, whereas PAb1620 was negative in 20. The tumours with poor histological response to ILP with TNF-alpha and melphalan showed significantly higher levels of p53-mutated protein. CONCLUSIONS: Our results might be a clue to a role of p53 protein status in TNF-alpha and melphalan response in clinical use.
Resumo:
BACKGROUND: Infliximab (IFX), adalimumab (ADA), and certolizumab pegol (CZP) have similar efficacy in induction and maintenance of clinical remission in Crohn's disease (CD). Given the comparable nature of these drugs, patient preferences may influence the choice of the product. We aimed to identify factors that may contribute to CD patients' decision in selecting one anti-tumor necrosis factor (TNF) agent over the others. METHODS: A prospective survey was performed among anti-TNF-naïve CD patients. Prior to completion of a questionnaire, patients were provided with a written description of the three anti-TNF agents, focusing on indications, mode of administration, side effects, and scientific evidence of efficacy and safety for each drug. RESULTS: One hundred patients (47 females, mean age 45 ± 16 years, range 19-81) with an ileal, colonic, or ileocolonic (33%, 40%, and 27%, respectively) disease location completed the questionnaire. Based on the information provided, 36% of patients preferred ADA, 28% CZP, and 25% IFX, whereas 11% were undecided. The patients' decision in selecting a specific anti-TNF drug was influenced by the following factors: ease of use (69%), time required for therapy (34%), time interval between application of the drug (31%), scientific evidence for efficacy (19%), and fear of syringes (10%). CONCLUSIONS: The majority of patients preferred anti-TNF medications that were administered by subcutaneous injection rather than by intravenous infusion. Ease of use and time required for therapy were two major factors influencing the patients' selection of a specific anti-TNF drug. Patients' individual preferences should be taken into account when prescribing anti-TNF drugs. (Inflamm Bowel Dis 2012).
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OBJECTIVE: Juvenile dermatomyositis (DM) is a systemic autoimmune disorder of unknown immunopathogenesis in which the immune system targets the microvasculature of skeletal muscles, skin, and other organs. The current mainstay of therapy is a steroid regimen in combination with other immunosuppressive treatments. To date, no validated markers for monitoring disease activity have been identified, which hampers personalized treatment. This study was undertaken to identify a panel of proteins specifically related to active disease in juvenile DM. METHODS: We performed a multiplex immunoassay for plasma levels of 45 proteins related to inflammation in 25 patients with juvenile DM in 4 clinically well-defined groups, as determined by clinical activity and treatment. We compared them to 14 age-matched healthy children and 8 age-matched children with nonautoimmune muscle disease. RESULTS: Cluster analysis of circulating proteins showed distinct profiles for juvenile DM patients and controls based on a group of 10 proteins. In addition to CXCL10, tumor necrosis factor receptor type II (TNFRII) and galectin 9 were significantly increased in active juvenile DM. The levels of these 3 proteins were tightly linked to active disease and correlated with clinical scores (as measured by the Childhood Myositis Assessment Scale and physician's global assessment of disease activity on a visual analog scale). CONCLUSION: Our findings indicate that CXCL10, TNFRII, and galectin 9 correspond to disease status in juvenile DM and thus could be helpful in monitoring disease activity and guiding treatment. Furthermore, they might provide new knowledge about the pathogenesis of this autoimmune disease.
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Glucocorticoid-induced tumor necrosis factor receptor (GITR) is a member of the tumor necrosis factor receptor superfamily, is expressed in T lymphocytes, and exerts an anti-apoptotic function in these cells. We reported that GITR is also highly expressed in the skin, specifically in keratinocytes, and that it is under negative transcriptional control of p21(Cip1/WAF1), independently from the cell cycle. Although GITR expression is higher in p21-deficient keratinocytes and skin, it is down-modulated with differentiation and in response to UVB. The combined analysis of keratinocytes with increased GITR expression versus normal keratinocytes and skin of mice with a disruption of the GITR gene indicates that this protein protects keratinocytes from UVB-induced apoptosis both in vitro and in vivo.
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Metadherin (MTDH), the newly discovered gene, is overexpressed in more than 40% of breast cancers. Recent studies have revealed that MTDH favors an oncogenic course and chemoresistance. With a number of breast cancer cell lines and breast tumor samples, we found that the relative expression of MTDH correlated with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) sensitivity in breast cancer. In this study, we found that knockdown of endogenous MTDH cells sensitized the MDA-MB-231 cells to TRAIL-induced apoptosis both in vitro and in vivo. Conversely, stable overexpression of MTDH in MCF-7 cells enhanced cell survival with TRAIL treatment. Mechanically, MTDH down-regulated caspase-8, decreased caspase-8 recruitment into the TRAIL death-inducing signaling complex, decreased caspase-3 and poly(ADP-ribose) polymerase-2 processing, increased Bcl-2 expression, and stimulated TRAIL-induced Akt phosphorylation, without altering death receptor status. In MDA-MB-231 breast cancer cells, sensitization to TRAIL upon MTDH down-regulation was inhibited by the caspase inhibitor Z-VAD-fmk (benzyloxycarbonyl-VAD-fluoromethyl ketone), suggesting that MTDH depletion stimulates activation of caspases. In MCF-7 breast cancer cells, resistance to TRAIL upon MTDH overexpression was abrogated by depletion of Bcl-2, suggesting that MTDH-induced Bcl-2 expression contributes to TRAIL resistance. We further confirmed that MTDH may control Bcl-2 expression partly by suppressing miR-16. Collectively, our results point to a protective function of MTDH against TRAIL-induced death, whereby it inhibits the intrinsic apoptosis pathway through miR-16-mediated Bcl-2 up-regulation and the extrinsic apoptosis pathway through caspase-8 down-regulation.
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Adherence to aMediterranean diet (MD) is associated with a reduced risk of coronary heart disease. However, themolecular mechanisms involved are not fully understood. The aim of this studywas to compare the effects of 2MD with those of a lowfat- diet (LFD) on circulating inflammatory biomarkers related to atherogenesis. A total of 516 participants included in the PreventionwithMediterraneanDiet Studywere randomized into 3 intervention groups [MD supplementedwith virgin olive oil (MD-VOO); MD supplemented with mixed nuts (MD-Nuts); and LFD]. At baseline and after 1 y, participants completed FFQ and adherence to MD questionnaires, and plasma concentrations of inflammatory markers including intercellular adhesion molecule-1(ICAM-1), IL-6, and 2 TNF receptors (TNFR60 and TNFR80) were measured by ELISA. At 1 y, the MD groups had lower plasma concentrations of IL-6, TNFR60, and TNFR80 (P , 0.05), whereas ICAM-1, TNFR60, and TNFR80 concentrations increased in the LFD group (P , 0.002). Due to between-group differences, participants in the 2 MD groups had lower plasma concentrations of ICAM-1, IL-6, TNFR60, and TNFR80 compared to those in the LFD group (P # 0.028). When participants were categorized in tertiles of 1-y changes in the consumption of selected foods, those in the highest tertile of virgin olive oil (VOO) and vegetable consumption had a lower plasma TNFR60 concentration compared with those in tertile 1 (P,0.02).Moreover, the only changes in consumption thatwere associated with 1-y changes in the geometricmean TNFR60 concentrations were those of VOO and vegetables (P = 0.01). This study suggests that a MD reduces TNFR concentrations in patients at high cardiovascular risk.
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Induction of apoptosis by tumor necrosis factor (TNF) is modulated by changes in the expression and activity of several cell cycle regulatory proteins. We examined the effects of TNF (1-100 ng/ml) and butyrolactone I (100 µM), a specific inhibitor of cyclin-dependent kinases (CDK) with high selectivity for CDK-1 and CDK-2, on three different cancer cell lines: WEHI, L929 and HeLa S3. Both compounds blocked cell growth, but only TNF induced the common events of apoptosis, i.e., chromatin condensation and ladder pattern of DNA fragmentation in these cell lines. The TNF-induced apoptosis events were increased in the presence of butyrolactone. In vitro phosphorylation assays for exogenous histone H1 and endogenous retinoblastoma protein (pRb) in the total cell lysates showed that treatment with both TNF and butyrolactone inhibited the histone H1 kinase (WEHI, L929 and HeLa) and pRb kinase (WEHI) activities of CDKs, as compared with the controls. The role of proteases in the TNF and butyrolactone-induced apoptosis was evaluated by comparing the number and expression of polypeptides in the cell lysates by gel electrophoresis. TNF and butyrolactone treatment caused the disappearance of several cellular protein bands in the region between 40-200 kDa, and the 110- 90- and 50-kDa proteins were identified as the major substrates, whose degradation was remarkably increased by the treatments. Interestingly, the loss of several cellular protein bands was associated with the marked accumulation of two proteins apparently of 60 and 70 kDa, which may be cleavage products of one or more proteins. These findings link the decrease of cyclin-dependent kinase activities to the increase of protease activities within the growth arrest and apoptosis pathways induced by TNF.
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We demonstrated that 4 mM butyrate induces apoptosis in murine peritoneal macrophages in a dose- and time-dependent manner as indicated by studies of cell viability, flow cytometric analysis of annexin-V binding, DNA ladder pattern and the determination of hypodiploid DNA content. The activity of caspase-3 was enhanced during macrophage apoptosis induced by butyrate and the caspase inhibitor z-VAD-FMK (100 µM) inhibited the butyrate effect, indicating the major role of the caspase cascade in the process. The levels of butyrate-induced apoptosis in macrophages were enhanced by co-treatment with 1 µg/ml bacterial lipopolysaccharide (LPS). However, our data indicate that apoptosis induced by butyrate and LPS involves different mechanisms. Thus, LPS-induced apoptosis was only observed when macrophages were primed with IFN-gamma and was partially dependent on iNOS, TNFR1 and IRF-1 functions as determined in experiments employing macrophages from various knockout mice. In contrast, butyrate-induced macrophage apoptosis was highly independent of IFN-gamma priming and of iNOS, TNFR1 and IRF-1 functions.