Project description:TNF (tumour necrosis factor alpha) induces tolerance towards itself in experimental liver injury. Tolerance induction has been shown to be dependent on TNFR1 (TNF receptor 1) signalling, but mechanisms and mediators of TNF-induced hepatic tolerance are unknown. We investigated the TNF-inducible gene-expression profile in livers of TNFR2-/- mice, using cDNA array technology. We found that, out of 793 investigated genes involved in inflammation, cell cycle and signal transduction, 282 were expressed in the mouse liver in response to TNF via TNFR1. Among those, expression of 78 genes was induced, while expression of 60 genes was reduced. We investigated further the cellular expression of the 27 most prominently induced genes, and found that 20 of these genes were up-regulated directly in parenchymal liver cells, representing potentially protective proteins and possible mediators of TNF tolerance. In vitro experiments revealed that overexpression of SOCS1 (silencer of cytokine signalling 1), a member of the SOCS family of proteins, as well as of HO-1 (haem oxygenase-1), but not of SOCS2 or SOCS3, protected isolated primary mouse hepatocytes from TNF-induced apoptosis. The identification of protective genes in hepatocytes is the prerequisite for future development of gene therapies for immune-mediated liver diseases.
Project description:Tumour necrosis factor receptor type 2 (TNFR2, TNFRSF1B) is an essential receptor for various host-defence functions of tumour necrosis factor alpha (TNF). As part of studies to determine the structure of TNFR2, the formation, crystallization and preliminary X-ray diffraction analysis of the TNF-TNFR2 complex are described. The TNF-TNFR2 complex, which comprises one TNF trimer and three TNFR2 monomers, was confirmed and purified by size-exclusion chromatography. Crystals of the TNF-TNFR2 complex were obtained using polyethylene glycol 3350 as a precipitant. The crystal belonged to space group P2(1)2(1)2(1), with unit-cell parameters a = 74.5, b = 117.4, c = 246.8 A. Assuming the presence of two TNF-TNFR2 complexes in the asymmetric unit, the Matthews coefficient V(M) was 2.49 A(3) Da(-1) and the solvent content of the crystal was 50.7%. The crystal diffracted to 2.95 A resolution.
Project description:The tumour necrosis factor-like weak inducer of apoptosis (TWEAK) is a member of the tumour necrosis factor ligand family and has been shown to be overexpressed in tumoral cells together with the fibroblast growth factor-inducible 14 (Fn14) receptor. TWEAK-Fn14 interaction triggers a set of intracellular pathways responsible for tumour cell invasion and migration, as well as proliferation and angiogenesis. Hence, modulation of the TWEAK-Fn14 interaction is an important therapeutic goal. The targeting of protein-protein interactions by external agents, e.g., drugs, remains a substantial challenge. Given their intrinsic features, as well as recent advances that improve their pharmacological profiles, peptides have arisen as promising agents in this regard. Here, we report, by in silico structural design validated by cell-based and in vitro assays, the discovery of four peptides able to target TWEAK. Our results show that, when added to TWEAK-dependent cellular cultures, peptides cause a down-regulation of genes that are part of TWEAK-Fn14 signalling pathway. The direct, physical interaction between the peptides and TWEAK was further elucidated in an in vitro assay which confirmed that the bioactivity shown in cell-based assays was due to the targeting of TWEAK. The results presented here are framed within early pre-clinical drug development and therefore these peptide hits represent a starting point for the development of novel therapeutic agents. Our approach exemplifies the powerful combination of in silico and experimental efforts to quickly identify peptides with desirable traits.
Project description:Members of the tumor necrosis factor (TNF)-receptor (R) family may be involved in the tissue remodeling that occurs in the primate corpus luteum (CL) during development and regression. As a first step towards addressing this issue, studies assessed TNF ligand-R expression and regulation in CL collected from monkeys during the early (ECL, Days 3-5), mid (MCL, Days 7-8), mid-late (MLCL, Days 10-11), late (LCL, Days 14-16), and very late (VLCL, menses) luteal phase of the menstrual cycle. CL were also collected after gonadotropin and/or steroid ablation and replacement (with hLH and the progestin R5020) for 3 days at mid-late luteal phase. TNF-alpha, -beta, FAS ligand (FASL), and TNF-R1 mRNA levels were two- to sixfold greater (P < 0.05) at the MLCL or LCL phase as compared to earlier (ECL, MCL). In contrast, TNF-R2 and FAS mRNA levels did not change during the luteal phase. Immunohistochemical staining for TNF-beta, TNF-R1, TNF-R2, FAS, and FASL was observed in luteal cells, whereas only TNF-beta staining was observed in endothelial cells. Several TNF-R components were influenced by LH and/or steroid ablation; notably, steroid ablation reduced (P < 0.05) luteal TNF-alpha, but not TNF-beta, mRNA levels, which was prevented by progestin treatment. In contrast, steroid ablation increased (P < 0.05) luteal cell immunostaining for FAS and FASL, which was reduced by progestin treatment. Thus, several members of the TNF R-ligand family are expressed in the primate CL in an LH- and/or progestin-dependent manner. Peak expression in the late luteal phase may signify a role for the TNF-R system in death receptor-mediated apoptosis during luteolysis.
Project description:ObjectivesThis case-controlled study aimed to identify the association of tumor necrosis factor (TNF)α-1031 and TNFβ+ 252 gene polymorphisms between chronic rhinosinusitis (CRS) and healthy controls. Another purpose of this study was to investigate the associations of these gene polymorphisms with factors related to CRS.MethodsAll deoxyribonucleic acid (DNA) samples were genotyped for TNFα-1031 and TNFβ+252 genes by mean of polymerase chain reaction (PCR) and restriction fragment length polymorphisms (RFLP). The statistical analysis were carried out using chi-square test or Fisher exact test to determine the associations of these gene polymorphisms in CRS. Multiple logistic regression was performed to evaluate the associations of these gene polymorphisms in CRS and its related risk factors.ResultsThe genotype and allele frequencies of TNFα-1031 and TNFβ+252 gene did not show any significant associations between CRS and healthy controls. However, a significantly statistical difference of TNFα-1031 was observed in CRS participants with atopy (P-value, 0.045; odds ratio, 3.66) but not in CRS with asthma or aspirin intolerance.ConclusionAlthough the presence of TNFα-1031 and TNFβ+252 gene polymorphisms did not render any significant associations between CRS and healthy control, this study suggests that TNFα-1031 gene polymorphisms in CRS patients with atopy may be associated with increase susceptibility towards CRS.
Project description:Tumour necrosis factor (TNF), an important proinflammatory cytokine, plays a role in the regulation of cell differentiation, proliferation and death, as well as in inflammation, innate and adaptive immune responses, and also implicated in a wide variety of human diseases. The presence of DNA sequence variations in regulatory region might interfere with transcription of TNF gene, influencing the circulating level of TNF and thus increases the susceptibility to human diseases (infectious, cancer, autoimmune, neurodegenerative and other diseases). In this review, we have comprehensively analysed various published case-control studies of different types of human diseases, in which TNF gene polymorphism played a role, and computationally predicted several single nucleotide polymorphisms (SNPs) lie in transcription factor-binding sites (TFBS) of transcription factors (TFs). It has been observed that TNF enhancer polymorphism is implicated in several diseases, and TNF rs1800629 and rs361525 SNPs are the most important in human disease susceptibility as these might influence the transcription of TNF gene. Thirty-two SNPs lies in TFBS of 20 TFs have been detected in the TNF upstream region. It has been found that TNF enhancer polymorphism influences the serum level of TNF in different human diseases and thus affects the susceptibility to diseases. The presence of DNA sequence variation in TNF gene causes the modification of transcriptional regulation and thus responsible for association of susceptibility/resistance with human diseases.
Project description:The purpose of this study is to assess the role of tumour necrosis factor (TNF) polymorphisms in the risk of developing bladder cancer and effect on tumour stage, grade and progression. In all, seven single-nucleotide polymorphisms in TNF were studied in 196 bladder cancer patients and 208 controls using a PCR-SSP genotyping technique. It was seen that there was a significant association of two polymorphisms in TNF with bladder cancer: the TNF+488A allele was found in 28.1% of patients compared with 14.9% of controls (P=0.0012). In addition, TNF-859T was found in 26.0% of patients compared with 14.4% of the controls (P=0.0036). The two loci were in tight linkage disequilibrium, that is, almost all the individuals having TNF+488A also had TNF-859T. Patients with the TNF+488A or TNF-859T were more likely to present with a moderately differentiated tumour than those patients without the uncommon allele. In all, 16.7% of patients with TNF+488A and 29.9% of patients without TNF+488A presented with a G1 tumour (P=0.015). A total of 14% of patients with TNF-859T and 30.5% of patients without TNF-859T presented with a G1 tumour (P=0.0043). There was no significant effect on time to first recurrence, stage progression or grade progression. In conclusion, a significant association between TNF polymorphisms TNF+488A and TNF-859T and risk of bladder cancer was detected in this study. Both these polymorphisms were associated with grade of tumour at presentation although there was no significant effect on subsequent tumour behaviour.
Project description:BackgroundEntamoeba histolytica cell migration is essential for the development of human amoebiasis (an infectious disease characterized by tissue invasion and destruction). The tissue inflammation associated with tumour necrosis factor (TNF) secretion by host cells is a well-documented feature of amoebiasis. Tumour necrosis factor is a chemoattractant for E. histolytica, and the parasite may have a TNF receptor at its cell surface.Methodsconfocal microscopy, RNA Sequencing, bioinformatics, RNA antisense techniques and histological analysis of human colon explants were used to characterize the interplay between TNF and E. histolytica.Resultsan antibody against human TNF receptor 1 (TNFR1) stained the E. histolytica trophozoite surface and (on immunoblots) binds to a 150-kDa protein. Proteome screening with the TNFR1 sequence revealed a BspA family protein in E. histolytica that carries a TNFR signature domain and six leucine-rich repeats (named here as "cell surface protein", CSP, in view of its cellular location). Cell surface protein shares structural homologies with Toll-Like receptors, colocalizes with TNF and is internalized in TNF-containing vesicles. Reduction of cellular CSP levels abolished chemotaxis toward TNF and blocked parasite invasion of human colon.Conclusionsthere is a clear link between TNF chemotaxis, CSP and pathogenesis.
Project description:ObjectiveWe compared the effectiveness of abatacept (ABA) versus a subsequent anti-tumour necrosis factor inhibitor (anti-TNF) in rheumatoid arthritis (RA) patients with prior anti-TNF use.MethodsWe identified RA patients from a large observational US cohort (2/1/2000-8/7/2011) who had discontinued at least one anti-TNF and initiated either ABA or a subsequent anti-TNF. Using propensity score (PS) matching (n:1 match), effectiveness was measured at 6 and 12 months after initiation based on mean change in Clinical Disease Activity Index (CDAI), modified American College of Rheumatology (mACR) 20, 50 and 70 responses, modified Health Assessment Questionnaire (mHAQ) and CDAI remission in adjusted regression models.ResultsThe PS-matched groups included 431 ABA and 746 anti-TNF users at 6 months and 311 ABA and 493 anti-TNF users at 12 months. In adjusted analyses comparing response following treatment with ABA and anti-TNF, the difference in weighted mean change in CDAI (range 6-8) at 6 months (0.46, 95% CI -0.82 to 1.73) and 12 months was similar (-1.64, 95% CI -3.47 to 0.19). The mACR20 responses were similar at 6 (28-32%, p=0.73) and 12 months (35-37%, p=0.48) as were the mACR50 and mACR70 (12 months: 20-22%, p=0.25 and 10-12%, p=0.49, respectively). Meaningful change in mHAQ was similar at 6 and 12 months (30-33%, p=0.41 and 29-30%, p=0.39, respectively) as was CDAI remission rates (9-10%, p=0.42 and 12-13%, p=0.91, respectively).ConclusionsRA patients with prior anti-TNF exposures had similar outcomes if they switched to a new anti-TNF as compared with initiation of ABA.
Project description:Advances in our understanding of the key mediators of chronic inflammation and tissue damage characteristic of rheumatoid arthritis (RA) have resulted in the development of novel therapies primarily targeting pro-inflammatory cytokines. Inhibitors of tumour necrosis factor (TNF) are the most widely used of the biological therapies at present with five different agents currently available; four are based on monoclonal anti-TNF antibodies and a soluble TNF receptor-Fc fusion protein. Long-term use of these molecules has proven to be highly effective in the majority of patients; however, around one-third have a suboptimal response potentially leading to further cartilage and bone damage, furthermore these agents are expensive compared with conventional therapies such as methotrexate. Many recent studies have attempted to identify therapeutic response biomarkers of TNF inhibitors which could be used to improve therapeutic targeting. The presence of rheumatoid factor and anti-cyclic citullinated protein antibodies, present in around 65% of RA patients, are associated with a poorer response to anti-TNF agents. Poorer response is also associated with levels of C-reactive protein and cartilage degradation product at initiation of treatment. Intriguingly, genetic studies of variants of TNF and of genes encoding members of the Toll-like receptors, nuclear factor-kappa B and p38 mitogen-activated protein kinase signalling families have been associated with response to individual anti-TNF agents. Continued advances in technologies such as ultra high throughput sequencing and proteomics should facilitate the discovery of additional biomarkers of response to anti-TNF resulting in improved disease control and quality of life for RA patients and reduced costs for healthcare funders.