The aim of this study is to explore the spatial association of critical genomic elements in the effect of TNF-α on matrix metalloproteinase-9 (MMP-9) expression in human leukemia U937 cells. TNF-α up-regulated MMP-9 protein expression and mRNA level in U937 cells, and Akt-mediated-NFκB/p65 activation and JNK-mediated c-Jun activation were proven to be involved in TNF-α-induced MMP-9 up-regulation. Promoter luciferase activity assay revealed that NFκB (nt-600) and AP-1 (nt-79) binding sites were crucial for TNF-α-induced transcription of MMP-9 gene. The results of a chromatin immunoprecipitation assay indicated that TNF-α reduced histone deacetylase-1 (HDAC-1) recruitment but increased p300 (a histone acetyltransferase) recruitment to MMP-9 promoter regions surrounding NFκB and AP-1 binding sites. Consistently, TNF-α increased enrichment of the acetylated histone H3 mark on MMP-9 promoter regions. DNA affinity purification assay revealed that p300 and HDAC1 could bind oligonucleotides containing AP-1/c-Jun and NFκB/p65 binding sites. Chromosome conformation capture assay showed that TNF-α stimulated chromosomal loops in the MMP-9 promoter via NFκB/p65 and AP-1/c-Jun. The p300-associated acetyltransferase activity was crucial for p65/c-Jun-mediated DNA looping, and inhibition of HDAC activity increased the level of DNA looping. Reduction in the level of DNA looping eliminated all TNF-α-stimulated MMP-9 up-regulation. Taken together, our data suggest that p65/c-Jun-mediated DNA looping is involved in TNF-α-induced MMP-9 up-regulation and that the recruitment of p300 or HDAC1 to NFκB and AP-1 binding sites modifies the level of DNA looping.Read more
Benzo[a]pyrene (B[a]P) is a carcinogen in cigarette smoke. We found that B[a]P induced SIRT1 in human bronchial epithelial BEAS-2B cell. SIRT1 was overexpressed in the lung of B[a]P-exposed mice and in human lung cancer biopsies. SIRT1 up-regulated TNF-α and β-catenin and down-regulated the membrane fraction of E-cadherin. In addition, SIRT1 promoted invasion, migration and tumorigenesis of BEAS-2B cells in nude mice upon B[a]P exposure. Thus, SIRT1 is involved in B[a]P-induced transformation associated with activation of the TNF-α/β-catenin axis and is as a potential therapeutic target for lung cancer.Read more
TNFα receptors are constitutively overexpressed in tumor cells, correlating to sustain elevated NFκB and monocyte chemotactic protein-1 (MCP-1/CCL2) expression. The elevation of CCL2 evokes aggressive forms of malignant tumors marked by tumor associated macrophage (TAM) recruitment, cell proliferation, invasion and angiogenesis. Previously, we have shown that the organo-sulfur compound diallyl disulfide (DADS) found in garlic (Allium sativum) attenuates TNFα induced CCL2 production in MDA-MB-231 cells. In the current study, we explored the signaling pathways responsible for DADS suppressive effect on TNFα mediated CCL2 release using PCR Arrays, RT-PCR and western blots. The data in this study show that TNFα initiates a rise in NFκB mRNA, which is not reversed by DADS. However, TNFα induced heightened expression of IKKε and phosphorylated ERK. The expression of these proteins corresponds to increased CCL2 release that can be attenuated by DADS. CCL2 induction by TNFα was also lessened by inhibitors of p38 (SB202190) and MEK (U0126) but not JNK (SP 600125), all of which were suppressed by DADS. In conclusion, the obtained results indicate that DADS down regulates TNFα invoked CCL2 production primarily through reduction of IKKε and phosphorylated-ERK, thereby impairing MAPK/ERK, and NFκB pathway signaling. Future research will be required to evaluate the effects of DADS on the function and expression of TNFα surface receptors.Read more
Chronic alcohol exposure exerts numerous adverse effects, although the specific mechanisms underlying these negative effects on different tissues are not completely understood. Alcohol also affects core properties of the circadian clock system, and it has been shown that disruption of circadian rhythms confers vulnerability to alcohol-induced pathology of the gastrointestinal barrier and liver. Despite these findings, little is known of the molecular interactions between alcohol and the circadian clock system, especially regarding implications for tissue-specific susceptibility to alcohol pathologies. The aim of this study was to identify changes in expression of genes relevant to alcohol pathologies and circadian clock function in different tissues in response to chronic alcohol intake.
Wild-type and circadian Clock(Δ19) mutant mice were subjected to a 10-week chronic alcohol protocol, after which hippocampal, liver, and proximal colon tissues were harvested for gene expression analysis using a custom-designed multiplex magnetic bead hybridization assay that provided quantitative assessment of 80 mRNA targets of interest, including 5 housekeeping genes and a predetermined set of 75 genes relevant for alcohol pathology and circadian clock function.
Significant alterations in expression levels attributable to genotype, alcohol, and/or a genotype by alcohol interaction were observed in all 3 tissues, with distinct patterns of expression changes observed in each. Of particular interest was the finding that a high proportion of genes involved in inflammation and metabolism on the array was significantly affected by alcohol and the Clock(Δ19) mutation in the hippocampus, suggesting a suite of molecular changes that may contribute to pathological change.
These results reveal the tissue-specific nature of gene expression responses to chronic alcohol exposure and the Clock(Δ19) mutation and identify specific expression profiles that may contribute to tissue-specific vulnerability to alcohol-induced injury in the brain, colon, and liver.Read more
Many studies suggested that cytokines interleukin (IL)-29, IL-32, and tumor necrosis factor alpha (TNF-α) are implicated in the pathogenesis of malignancies. The purpose of this study was to determine the clinical significance of the serum levels of IL-29, IL-32, and TNF-α in gastric cancer (GC) patients. Fifty-eight GC patients and 20 age- and sex-matched healthy controls were enrolled into this study. The median age at diagnosis was 59.5 years (range 32-82 years). Tumor localization of the majority of the patients was antrum (n = 42, 72.4 %), and tumor histopathology of the majority of the patients was diffuse (n = 43, 74.1 %). The majority of the patients had stage IV disease (n = 41, 70.7 %). Thirty-six (62.1 %) patients had lymph node involvement. The median follow-up time was 66 months (range 1 to 97.2 months). The baseline serum IL-29 concentrations were not different between patients and controls (p = 0.627). The baseline serum IL-32 and TNF-α concentrations of the GC patients were significantly higher (for IL-32, p = 0.014; for TNF-α, p = 0.001). Gender, localization, histopathology, tumor, and lymph node involvement were not found to be correlated with serum IL-29, IL-32, and TNF-α concentrations (p > 0.05). Patients without metastasis (p = 0.01) and patients who responded to chemotherapy (p = 0.04) had higher serum IL-29 concentrations. Patients older than 60 years had higher serum IL-32 (p = 0.002). Serum IL-29, IL-32, and TNF-α levels were not associated with outcome (p = 0.30, p = 0.51, and p = 0.41, respectively). In conclusion, serum levels of IL-32 and TNF-α may be diagnostic markers, and serum IL-29 levels may be associated with good prognosis in patients with GC.Read more
We studied polymorphism of three positions of promoter region of TNF alpha gene in patients with ischemic heart disease (IHD), development of unstable angina (UA) and acute myocardial infarction (MI). Analysis of frequencies of genotypes in position A308 showed that heterozygotness in patients with cardiovascular diseases significantly decreased. Lowering of risk of development of MI in carriers of heterozygous variant of the gene in position A308 was shown. In the group of patients with Q wave MI frequency of A308 AA genotype rose.Read more
Polymorphisms in tumor necrosis factor alpha (TNF-α) gene are emerging as key determinants of gastric diseases. The TNF-α(-308) (G/A) and TNF-α(-238) (G/A) single-nucleotide polymorphisms SNPs are the most extensively studied. However, all these studies are conducted in Caucasian and Asian populations. Thus, for the first time in Africa, we sought to investigate whether polymorphisms in TNF-α gene were associated with the development of gastric pathology in Morocco. Two SNPs located in the promoter region (positions -308 and -238) in TNF-α gene were genotyped in 244 individuals (170 patients and 74 healthy controls). Odds ratios (ORs) and 95% confidence intervals (CI) were estimated using logistic regression analysis. The TNF-α(-238) (G/A) genotype was significantly associated with a high risk of gastritis and gastric cancer (GC) (P = 0.001 and P = 0.002, resp.). Furthermore, a new polymorphism located in the promoter region at position -193 in TNF-α gene was identified. The distribution of this SNP was markedly different in patients suffering from ulcers. The association between TNF-α(-193) (G/A) genotype and high risk of ulcer was significant (P = 0.03). These results suggest that the TNF-α(-193) (G/A) allele has a protective function against gastric cancer by developing ulcer.Read more
Several studies on the association of tumor necrosis factor alpha (TNF-α) polymorphisms with recurrent pregnancy loss (RPL) risk have reported conflicting results. The present meta-analysis was conducted to provide a more precise estimation of these relationships and to investigate the real association between TNF-α polymorphisms and RPL.
An extensive eligible literature search for relevant studies was conducted on PubMed, Embase, and The Cochrane Library from their inceptions to May 12, 2015. Specific inclusion criteria were used to evaluate articles. The odds ratio (OR) with 95% confidence intervals (CIs) were used to assess the strength of associations. Statistical analyses were performed by the STATA12.0 software.
10 case-control studies including 1430 RPL patients and 1727 healthy controls were identified. Meta-analysis indicated that TNF-α-308G/A (rs1800629) polymorphism in the TNF-α gene correlated with elevated RPL risk whereas no significant association was observed between TNF-α-238G/A (rs361625) and RPL.
The current meta-analysis demonstrates that TNF-α-308G/A polymorphism in the TNF-α gene is associated with susceptibility to RPL.Read more
To evaluate the outcome of anti-tumor necrosis factor alpha (anti-TNFα) therapy in outpatients with ulcerative colitis at a tertiary referral center.
All patients with a confirmed diagnosis of ulcerative colitis undergoing therapy with infliximab and/or adalimumab at the outpatient clinic for inflammatory bowel diseases at the University Hospital Heidelberg between January 2011 and February 2014 were retrospectively enrolled. Patients with a follow-up period of less than 6 mo from start of anti-TNFα therapy were excluded. Medical records of all eligible individuals were carefully reviewed. Steroid-free clinical remission of a duration of at least 3 mo, colectomy rate, duration of anti-TNFα therapy, need for anti-TNFα dose escalation, and the occurrence of adverse events were evaluated as the main outcome parameters.
Seventy-two patients were included (35 treated with infliximab, 17 with adalimumab, 20 with both consecutively). Median follow-up was 27 mo (range: 6-87 mo). Steroid-free clinical remission was achieved by 22.2% of the patients (median duration: 21 mo until end of follow-up; range: 3-66 mo). Patients attaining steroid-free clinical remission displayed lower hemoglobin and albumin blood levels at the start of treatment than those who did not achieve remission. The overall colectomy rate was 20.8%. Nearly 50% of the patients underwent anti-TNFα dose escalation during the follow-up period. For both the infliximab and the adalimumab treated patients, non-response to anti-TNFα therapy was the major reason for treatment discontinuation. 18.2% of the infliximab-treated patients and 13.5% of the adalimumab-treated patients had to discontinue their therapy due to adverse events.
Real-life remission rates of ulcerative colitis under anti-TNFα are overall low, but some patients have a clear long-term benefit.Read more
We have recently observed significantly elevated serum tumor necrosis factor-alpha (TNF-alpha) levels during human liver allograft rejection. Although increased TNF activity has been reported in rejecting rat cardiac and renal allografts, this represents the first report of an animal model utilizing immunotherapy directed against TNF. Intraabdominal heart transplants (Buffalo to Lewis) were performed. Cardiac rejection was defined as cessation of a palpable beat and confirmed at laparotomy. Control animals received no immunotherapy and experienced rejection on Postoperative Day 11 +/- 0.4 (mean +/- SEM). Experimental animals received immunotherapy either intraperitoneally (ip) or intravenously (iv) from Days 1 to 10. Intraperitoneally administered anti-TNF-alpha prolonged graft survival to 16 +/- 2.7 days (P less than 0.05 vs controls), iv administration prolonged survival to 15 +/- 1.4 days (P less than 0.004). Animals treated with ip anti-TNF-beta survived 17 +/- 1.7 days (P less than 0.002 vs controls). Conversely, administration of purified TNF-alpha to graft recipients decreased graft survival to 7 +/- 0.4 days (P less than 0.001 vs controls). Serum samples analyzed in an L929 bioassay showed increased cytotoxic activity in control animals, corresponding to an increase in circulating TNF. This activity was partially abrogated in animals receiving immunotherapy. These data demonstrate that circulating levels of TNF are increased during rejection. Immunotherapy with anti-TNF-alpha or anti-TNF-beta prolongs graft survival, suggesting that TNF may play a role in the pathogenesis of acute allograft rejection.Read more