Tumor Necrosis Factor receptor-II Research Articles

Genetic deletion of TNFRII gene enhances the Alzheimer-like pathology in an APP transgenic mouse model via reduction of phosphorylated IκBα.

Tumor necrosis factor receptor II (TNFRII) is one of the TNF receptor superfamily members and our recent pathological studies show that TNFRII is deficient in the brains of Alzheimer's disease (AD). However, the mechanisms of TNFRII in AD pathogenesis remain unclear. In the present study, by using the gene-targeting approach to delete TNFRII in AD transgenic mouse model, we found that, in the brain of APP23 mice with TNFRII deletion (APP23/TNFRII(-/-)), AD-like pathology, i.e. plaque formation and microglial activation, occurs as early as 6 months of age. To test whether the increased levels of Aβ plaques was due to elevated Aβ, we measured Aβ and found that Aβ levels indeed were significantly increased at this age. Because β-secretase, BACE1, is critical enzyme for Aβ production, we have examined BACE1 and found that BACE1 is increased in both protein levels and enzymatic activity as early as 6 months of age; Having shown that BACE1 promoter region contains NF-κB binding sites, we found that cytoplasmic NF-κB was elevated and SUMO1 binding to IκBα was decreased. To further verify these findings, we have overexpressed TNFRII and identified that overexpressing TNFRII can reverse the findings from APP23/TNFRII(-/-) mice. Altogether, our results demonstrate novel roles of TNFRII in the regulation of Aβ production, suggesting a potential therapeutic strategy for AD by up-regulating TNFRII levels and elevating phosphorylated IκBα by SUMOylation.

Tumor necrosis factor receptor-II nt587 polymorphism in Chinese Han patients with ankylosing spondylitis.

We aimed to explore the association between the onset of ankylosing spondylitis (AS) and nt587 polymorphisms of the tumor necrosis factor receptor II (TNFRII) gene in the Han population of Hunan Province, China. Correlation analysis was performed in a case-control study involving 100 AS cases and 100 healthy controls. The nt587 single nucleotide polymorphism of the TNFRII gene was examined by polymerase chain reaction-restriction fragment length polymorphism. The relationship between AS and the frequencies of genotypes and alleles in TNFRII nt587 were analyzed using the SPSS software. There were 43 cases with the TNFRII nt587 T/T genotype, 32 cases with the TNFRII nt587 T/G genotype, and 25 cases with the TNFRII nt587 G/G genotype. In the 100 healthy controls, 56 subjects had the TNFRII nt587 T/T genotype, 34 had the TNFRII nt587 T/G genotype, and 10 had the TNFRII nt587 G/G genotype. The G allele frequency of the AS group was significantly higher (χ(2) = 8.734, P = 0.003) than that in the control group (41.0 vs 27.0%). The odds ratio (OR) in AS cases with the TNFRII nt587 G/G genotype was 3.256, which was obviously higher than in those with T/G (OR = 1.226) and T/T (OR = 1.0) genotype. The polymorphism at position nt587 of the TNFRII gene was found to be associated with AS, and the TNFRII nt587 G allele may play an important role in AS susceptibility. The TNFRII nt587 G/G genotype may increase the risk of developing AS in the Hunan population.

Adipocytokine levels in women with anorexia nervosa. Relationship with weight restoration and disease duration

Starvation-induced depletion of fat stores in anorexia nervosa (AN) is known to be accompanied by alterations in some circulating adipocytokines. We analyzed a panel of circulating adipocytokines in women with AN compared with normal-weight controls and their relation with the disease duration and weight restoration. We analyzed circulating adipocytokine levels in 28 patients with AN and in 33 normal-weight controls who were eating healthily. We determined by enzyme-linked immunosorbent assay the circulating levels of total and high molecular weight (HMW) adiponectin, lipocalin-2 (LCN2), leptin, tumor necrosis factor receptor-II (TNFRII), interleukin-6 (IL6), adipocyte fatty acid binding protein-4 (FABP4), ghrelin, and resistin. The two circulating forms of adiponectin are higher in AN women compared with controls. Both total and HMW adiponectin related negatively to the duration of the disease (r = -0.372, p = 0.033; r = -0.450, p = 0.038, respectively). Furthermore, the lipid binding-proteins LCN2 and FABP4 are lower in AN compared to the control group. Finally, leptin levels are lower in AN against controls and correlated positively with disease duration (r = 0.537, p = 0.007). Resistin, ghrelin, TNFRII, and IL6 have similar values in both groups, although TNFRII and ghrelin related negatively to body mass index variation at the end of treatment (r = -0.456, p = 0.039; r = -0.536, p = 0.015, respectively). These results suggest there is a need to investigate if changes in adipocytokine levels could serve as weight restoration biomarkers. Further studies are warranted to elucidate the specific role of these molecules in the timing of weight restoration.

Differential control of Helios+/− Treg development by monocyte subsets through disparate inflammatory cytokines

AbstractFoxp3+ regulatory T cells (Tregs) play a pivotal role in control of autoimmunity and pathological immune responses. Helios, the Ikarus family transcription factor, binds to the Foxp3 promoter, stabilizing its expression, and is expressed in 70% of peripheral Tregs of healthy individuals. This frequency is altered during malignancy, infection, and autoimmunity, although the mechanisms that control proliferation and relative numbers of Helios+/− Tregs remain largely unknown. Using a T-cell–monocyte in vitro stimulation assay, we now show that proliferation of Helios+ Tregs is inhibited by CD16+ monocyte subset. Antibody blocking with anti–interleukin (IL)-12 reversed this inhibition, whereas addition of IL-12 suppressed Helios+ Treg expansion, indicating that CD16+ monocyte control of Helios+ Treg numbers is mediated through IL-12. In contrast, proliferation of Helios− Tregs, which express higher levels of tumor necrosis factor receptor II (TNFRII), was suppressed by TNF-α, whereas anti–TNF-α and anti-TNFRII reversed the inhibition. CD16− monocyte subset was mainly responsible for TNF-α–mediated control of Helios− Treg expansion. Altogether, these data suggest a differential role for monocyte subsets in control of Helios+/− Treg development that is mediated by distinct inflammatory cytokines. These data may have important implications for understanding the pathogenesis as well as control of chronic inflammatory and autoimmune diseases.

Clinical correlates of change in inflammatory biomarkers: The Framingham Heart Study

ObjectivesTraditional clinical risk factors are associated with inflammation cross-sectionally, but associations of longitudinal variation in inflammatory biomarkers with corresponding changes in clinical risk factors are incompletely described. We sought to analyze clinical factors associated with change in inflammation in the community. MethodsWe studied 3013 Framingham Offspring (n = 2735) and Omni Cohort (n = 278) participants (mean age 59 years, 55% women, 9% ethnic/racial minority) who attended two consecutive examination cycles (mean 6.7 years apart). We selected ten inflammatory biomarkers representing distinctive biological functions: C-reactive protein (CRP), intercellular adhesion molecule-1, interleukin-6, isoprostanes, lipoprotein-associated phospholipase-2 (Lp-PLA2) activity, Lp-PLA2-mass, monocyte chemoattractant protein-1, osteoprotegerin, P-selectin, and tumor necrosis factor receptor II (TNFRII). We constructed multivariable-adjusted regression models to assess the relations of baseline, follow-up and change in clinical risk factors with change in biomarker concentrations over time. ResultsBaseline, follow-up and change in clinical risk factors explain a moderate amount of the variation in biomarker concentrations across 2 consecutive examinations (ranging from r2 = 0.28 [TNFRII] up to 0.52 [Lp-PLA2-mass]). In multivariable models, increasing body-mass index, smoking initiation, worsening lipid profile, and increasing waist size were associated with increasing concentrations of several biomarkers. Conversely, hypercholesterolemia therapy and hormone replacement cessation were associated with decreasing concentrations of biomarkers such as CRP, Lp-PLA2-mass and activity. ConclusionCardiovascular risk factors have different patterns of association with longitudinal change in inflammatory biomarkers and explain modest amounts of variability in biomarker concentrations. Nevertheless, a substantial proportion of longitudinal change in inflammatory markers is not explained by traditional risk factors.

Associations of Candidate Biomarkers of Vascular Disease with the Ankle-Brachial Index and Peripheral Arterial Disease

The use of multiple biomarkers representing various etiologic pathways of atherosclerosis may improve the prediction of interindividual variation in the ankle-brachial index (ABI). To this end, we investigated associations of 47 candidate biomarkers with the ABI and presence of peripheral arterial disease (PAD) in African-Americans (AAs) and non-Hispanic whites (NHWs). Study participants included 1,291 AAs (71.1% women, mean age, 63.4±9.3 years) and 1,152 NHWs (57.5% women, mean age 58.5±10.1 years) belonging to hypertensive sibships. Peripheral arterial disease was defined as an ABI ≤ 0.90. Circulating levels of 47 candidate biomarkers were log-transformed before analysis because of skewed distribution. Multivariate regression analyses were used to identify biomarkers associated with ABI or PAD independently of age, sex, conventional risk factors, and medication use. After adjustment for covariates, higher levels of nine biomarkers were associated with a lower ABI in AAs (all P ≤ 0.005); these biomarkers were C-reactive protein (CRP), interleukin-6, tumor necrosis factor receptor-II (TNF-R II), lipoprotein(a), N-terminal pro-brain natriuretic peptide (NT-proBNP), pro-atrial natriuretic peptide, C-terminal pro-arginine vasopressin, osteoprotegerin, and fibrinogen. Three biomarkers - myeloperoxidase, NT-proBNP, and D-dimer - were associated with ABI in NHWs (all P ≤ 0.01). C-reactive protein, interleukin-6, TNF-R II, lipoprotein(a), NT-proBNP, pro-atrial natriuretic peptide, D-dimer, and fibrinogen were associated with PAD (all P ≤ 0.005) in AAs after adjustment for covariates. None of the biomarkers were independently associated with PAD in NHWs. A multimarker approach improved the prediction of interindividual variation in the ABI in AAs and NHWs, and improved prediction of the presence of PAD in AAs.

Effects of Intense Exercise and Moderate Caloric Restriction on Cardiovascular Risk Factors and Inflammation

Background Obesity is associated with insulin resistance, inflammation, metabolic dysfunction, and atherosclerosis. This study investigates the effects of weight loss, intense exercise, and moderate caloric restriction on insulin resistance, lipids, inflammatory biomarkers, carotid artery distensibility index (CaDI), and carotid intima media thickness (CIMT). Methods Seventeen sedentary morbidly obese contestants in the “Biggest Loser” television program completed the 7-month intense-exercise and moderate-restricting calories program; 3 were excluded due to lack of follow-up CIMT. Serum insulin level, glucose, lipid profile, high-sensitivity C-reactive protein (CRP), hemoglobin A1c (HbA1c), resistin, adiponectin, plasminogen activator inhibitor-1 (PAI-1), tumor necrosis factor receptor-II (TNFRII), lipoprotein a (Lp[a]), sex hormone binding globulin (SHBG), blood pressure, body fat, weight, CaDI, and CIMT were measured at baseline and 7-month follow-up. CIMT was measured 5-10 mm below the common carotid bifurcation during mid-diastolic phase. CaDI was defined as: (End-systole – End-diastole common-carotid cross-sectional area)/(End-diastole common-carotid cross-sectional-area × systemic pulse pressure) × 1000. Insulin resistance was calculated by homeostatic model assessment (HOMA) index. Results At 7-month follow-up, major reductions in weight (−39%), body fat (−66%), serum insulin level (−52%), glucose (−21%), high-sensitivity CRP (−81%), HbA1c (−11%), PAI-1 (−49%), TNFRII (−12%), and CIMT (−25%), and increases in CaDI (132%), resistin (344%), adiponectin (94%), Lp(a) (73%), and SHBG (94%) were observed. The improvement in CaDI was positively correlated with increases in adiponectin, Lp(a), SBHG, and resistin ( r 2 = 0.86, P = .009), but inversely with PAI-1, TNFRII, CRP, and IR ( r 2 = −0.64, P = .01). Strong inverse correlation was noted between decreases in CIMT and increases in CaDI ( r 2 = 0.65, P = .001). Conclusion In morbidly obese individuals, intense exercise with moderate caloric restriction over 7 months is associated with a dramatic improvement in carotid vascular function and atherosclerosis risk factors, as well as a reduction in inflammatory biomarkers, lipids, insulin resistance, and CIMT.

Subclinical atherosclerosis is related to injury level but not to inflammatory parameters in spinal cord injury subjects

Cross-sectional. Individuals with spinal cord injury (SCI) exhibit increased carotid intima-media thickness (IMT) and are reported to be exposed to higher circulating levels of inflammatory mediators. This study evaluated the relationship between inflammatory markers and carotid surrogates of cardiovascular risk in subjects with SCI. São Paulo, Brazil. A total of 65 nondiabetic, nonhypertensive, sedentary, nonsmoker men (34 with SCI; 31 healthy subjects) were evaluated by medical history, anthropometry, routine laboratory tests, analysis of hemodynamic, inflammatory parameters and ultrasound examination of carotid arteries. Subjects with SCI (18 tetraplegic and 16 paraplegic) had lower systolic blood pressure (P = 0.009), higher serum C-reactive protein (P = 0.001), tumor necrosis factor (TNF) receptor-II (P = 0.02) and TNF receptor-I (P = 0.04) levels and increased in vitro production of interleukin-6 by mononuclear cells (P = 0.04), compared to able-bodied individuals. No differences in serum interleukin-6, e-selectin, intercellular adhesion molecule-1, vascular cell adhesion molecule-1 and transforming growth factor-β levels, or in vitro release of interleukin-10, interleukin-17 and interferon-γ by mononuclear cells, were detected between the studied groups. Common carotid IMT, but not internal carotid resistive index, was significantly higher in subjects with SCI (P<0.0001 adjusted for C-reactive protein and TNF receptor-II levels). In addition, tetraplegic subjects exhibited increased IMT (P = 0.002 adjusted for systolic blood pressure and body mass index), but similar levels of inflammatory mediators compared to paraplegic ones. Individuals with SCI exhibit a clustering of vascular and inflammatory surrogates of increased cardiovascular risk. Nevertheless, subclinical carotid atherosclerosis is related to injury level but not to increased inflammatory status in these subjects.

Serum levels of soluble Fas, soluble tumor necrosis factor-receptor II, interleukin-2 receptor and interleukin-8 as early predictors of hepatocellular carcinoma in Egyptian patients with hepatitis C virus genotype-4

BackgroundLiver disease progression from chronic hepatitis C virus (HCV) infection to hepatocellular carcinoma (HCC) is associated with an imbalance between T-helper 1 and T-helper 2 cytokines. Evaluation of cytokines as possible candidate biomarkers for prediction of HCC was performed using soluble Fas (sFas), soluble tumor necrosis factor receptor-II (sTNFR-II), interleukin-2 receptor (IL-2R) and interleukin-8 (IL-8).ResultsThe following patients were recruited: 79 with HCV infection, 30 with HCC, 32 with chronic liver disease associated with elevated liver enzyme levels (with or without cirrhosis) in addition to 17 with chronic HCV with persistent normal alanine aminotransferase levels (PNALT). Nine normal persons negative either for HCV or for hepatitis B virus were included as a control group. All persons were tested for sFas, sTNFR-II, IL-2R and IL-8 in their serum by quantitative ELISA. HCC patients had higher levels of liver enzymes but lower log-HCV titer when compared to the other groups. HCC patients had also significantly higher levels of sFas, sTNFR-II and IL-2R and significantly lower levels of IL-8 when compared to the other groups. Exclusion of HCC among patients having PNALT could be predicted with 90% sensitivity and 70.6% specificity when sTNFR-II is ≥ 389 pg/ml or IL-8 is < 290 pg/ml.ConclusionsSerum TNFR-II, IL-2Rα and IL-8, may be used as combined markers in HCV-infected cases for patients at high risk of developing HCC; further studies, however, are mandatory to check these findings before their application at the population level.

Parasite-Dependent Expansion of TNF Receptor II–Positive Regulatory T Cells with Enhanced Suppressive Activity in Adults with Severe Malaria

Severe Plasmodium falciparum malaria is a major cause of global mortality, yet the immunological factors underlying progression to severe disease remain unclear. CD4+CD25+ regulatory T cells (Treg cells) are associated with impaired T cell control of Plasmodium spp infection. We investigated the relationship between Treg cells, parasite biomass, and P. falciparum malaria disease severity in adults living in a malaria-endemic region of Indonesia. CD4+CD25+Foxp3+CD127lo Treg cells were significantly elevated in patients with uncomplicated (UM; n = 17) and severe malaria (SM; n = 16) relative to exposed asymptomatic controls (AC; n = 10). In patients with SM, Treg cell frequency correlated positively with parasitemia (r = 0.79, p = 0.0003) and total parasite biomass (r = 0.87, p<0.001), both major determinants for the development of severe and fatal malaria, and Treg cells were significantly increased in hyperparasitemia. There was a further significant correlation between Treg cell frequency and plasma concentrations of soluble tumor necrosis factor receptor II (TNFRII) in SM. A subset of TNFRII+ Treg cells with high expression of Foxp3 was increased in severe relative to uncomplicated malaria. In vitro, P. falciparum–infected red blood cells dose dependently induced TNFRII+Foxp3hi Treg cells in PBMC from malaria-unexposed donors which showed greater suppressive activity than TNFRII− Treg cells. The selective enrichment of the Treg cell compartment for a maximally suppressive TNFRII+Foxp3hi Treg subset in severe malaria provides a potential link between immune suppression, increased parasite biomass, and malaria disease severity. The findings caution against the induction of TNFRII+Foxp3hi Treg cells when developing effective malaria vaccines.

Relations of Inflammatory Biomarkers and Common Genetic Variants With Arterial Stiffness and Wave Reflection

Inflammation causes vascular dysfunction and perpetuates proatherosclerotic processes. We hypothesized that a broad panel of inflammatory biomarkers and single nucleotide polymorphisms in inflammatory genes is associated with vascular stiffness. We assessed 12 circulating inflammatory biomarkers (C-reactive protein, fibrinogen, interleukin-6, intercellular adhesion molecule-1, lipoprotein-associated phospholipase-A2 [mass and activity], monocyte chemoattractant protein-1, myeloperoxidase, CD40 ligand, osteoprotegerin, P-selectin, and tumor necrosis factor receptor-II) in relation to tonometry variables (central pulse pressure, mean arterial pressure, forward pressure wave, reflected pressure wave, carotid-femoral pulse wave velocity, and augmentation index) measured in 2409 Framingham Heart Study participants (mean age: 60 years; 55% women; 13% ethnic/racial minorities). Single nucleotide polymorphisms (n=2195) in 240 inflammatory candidate genes were related to tonometry measures in 1036 white individuals. In multivariable analyses, biomarkers explained <1% of any tonometry measure variance. Applying backward elimination, markers related to tonometry (P<0.01) were as follows: tumor necrosis factor receptor-II (inversely) with mean arterial pressure; C-reactive protein (positively) and lipoprotein-associated phospholipase-A2 (inversely) with reflected pressure wave; and interleukin-6 and osteoprotegerin (positively) with carotid-femoral pulse wave velocity. In genetic association analyses, lowest P values (false discovery rate <0.50) were observed for rs10509561 (FAS), P=6.6x10(-5) for central pulse pressure and rs11559271 (ITGB2), P=1.1x10(-4) for mean arterial pressure. These data demonstrate that, in a community-based sample, circulating inflammatory markers tumor necrosis factor receptor-II (mean arterial pressure), C-reactive protein, lipoprotein-associated phospholipase-A2 activity (reflected pressure wave), interleukin-6, and osteoprotegerin (carotid-femoral pulse wave velocity) were significantly but modestly associated with measures of arterial stiffness and wave reflection. Additional studies are needed to determine whether variation in inflammatory marker genes is associated with tonometry measures.

Increased activation-induced cell death of high IFN-γ–producing T H1 cells as a mechanism of T H2 predominance in atopic diseases

A dysregulated and T(H)2-biased immune response appears to be a key pathogenetic factor in atopic diseases. Increased activation and massive infiltration of T cells in the dermis without any evidence for the expansion of their numbers in peripheral blood characterize atopic dermatitis. To investigate differences and mechanisms of T(H)1 and T(H)2 cell activation-induced cell death (AICD) in atopic disease. Naive (CD4(+)CD45(+)RA) and memory (CD4(+)CD45(+)RO) T cells were isolated from healthy and atopic individuals. T(H)1 and T(H)2 subsets were in vitro differentiated. High IFN-gamma-producing T cells and CXCR3(+) T cells were purified, and AICD of isolated cells was determined in addition to expression of apoptosis receptors and caspase activation. T(H)1 cells, particularly their high IFN-gamma-producing fraction, and CXCR3(+) T cells showed significantly increased apoptosis in atopic individuals. During their in vitro differentiation, both T(H)1 and T(H)2 cells of atopic individuals showed increased apoptosis compared with the healthy control group, with a significantly high apoptosis in T(H)1 cells. Increased expression of Fas, Fas-ligand, tumor necrosis factor receptor-II, and caspase activation was detected on T(H)1 cells that underwent apoptosis. Neutralization experiments demonstrated a dominant role of IFN-gamma and Fas-Fas-ligand interaction-mediated suicide in T(H)1 cell AICD. Predominant T(H)2 profile in atopic diseases might be a result of the increased tendency to activation and apoptosis of high IFN-gamma-producing T(H)1 cells.

Neuroendocrine Modulation Induced by Selective Blockade of TNF‐α in Rheumatoid Arthritis

Tumor necrosis factor-alpha (TNFalpha) is a main actor in the pathogenesis of rheumatoid arthritis (RA), interacting with other molecules in complex mechanisms. The neuroendocrine system is known to be involved and Chromogranin A (CHGA) serum levels are elevated in patients with RA. We evaluated the effect of the selective blockade of TNF-alpha, induced by treatment with anti-TNF-alpha monoclonal antibodies (mAbs), on the serum levels of CHGA and on its correlation with TNF-alpha and TNF-alpha receptors (TNFRs) serum levels. Seven patients with RA have been treated with the anti-TNF-alpha mAb, infliximab. We measured the serum levels of TNF-alpha, its receptors (tumor necrosis factor receptor-I [TNFR-I] and tumor necrosis factor receptor-II [TNFR-II]), and CHGA before and during the treatment. We also measured, as a control, the serum levels of CHGA, TNF-alpha, and soluble TNFRs in 14 patients who were being treated with infliximab, adalimumab, or etanercept and in 20 matching negative controls. The serum levels of TNFR-I and TNFR-II, which are a sensitive marker for the TNF-alpha pathway, correlated with those of CHGA before treatment (Pearson's coefficient, respectively, 0.59 and 0.53). Treatment with anti-TNF-alpha mAb provided a significant clinical response in all patients and the correlation between CHGA and TNFR-I and TNFR-II was no more evident during treatment (respectively, -0.09 and -0.07). TNF-alpha blockade allows a clinical effect in patients with RA and modifies the correlation between CHGA and TNFRs, suggesting that TNF-alpha and CHGA reciprocally interfere in the pathogenesis of RA, through intermediate adaptors, whose identification warrants further studies.

Alleviation of hepatic steatosis accompanied by modulation of plasma and liver TNF-α levels by Trigonella foenum graecum (fenugreek) seeds in Zucker obese (fa/fa) rats

Oral supplements of fenugreek (Trigonella foenum graecum) seeds (Fen) have been shown to treat glucose and lipid homeostasis in several metabolic disorders; however, its ability to alleviate obesity-associated pathologies is not known. The main objective of this study was to evaluate the effect of Fen in Zucker obese rats (Ob), an animal model of obesity and related disorders, such as dyslipidemia and hepatic steatosis. Female Zucker (6-week-old) Ob and lean (Ln) rats were randomly grouped (n = 8 rats/group) to receive either basal or 5% Fen-supplemented AIN-93G diets for 8 weeks, and then were euthanized. Histopathology and biochemical parameters in the liver together with plasma biochemistry were assessed. Obese rats had significantly higher (P < 0.05) body and liver weight, as well as plasma insulin, lactate, cholesterol, triglyceride and tumor necrosis factor (TNF)-alpha compared to their Ln counterparts. Fen significantly reduced (P < 0.05) the liver-weight of Ob rats in comparison to Ob rats fed basal diet (Control), while no effect was observed in the Ln rats. Fen treatment resulted in a lower P-value (P < 0.05). In addition, Ob rats on Fen-supplemented diets had fasting plama cholesterol and TNF-alpha levels, and significantly higher (P < 0.05) triglycerides in comparison to the control rats. Hepatic triglyceride level was significantly lower (P < 0.05) in Ob rats fed Fen supplemented diets in comparison to control. The levels of bound and soluble liver TNF-alpha (26 and 17 kDa, respectively) and TNF receptor-II (TNFR-II, 75 kDa) proteins were significantly lower (P < 0.05) in Ob than in Ln rats. Fen significantly lowered (P < 0.05) both the soluble and bound forms of TNF-alpha protein while significantly elevating (P < 0.05) TNFR-II in the livers of Ob rats compared to Ob Controls. These results demonstrate unequivocally that in a short-term preclinical evaluation, dietary Fen supplementation reduced the triglyceride accumulation in the liver, a hallmark feature of hepatic steatosis without affecting the plasma insulin or glucose levels in Zucker obese rats and suggest that TNF-alpha may play an important role in this process.

A functional polymorphism of the tumor necrosis factor receptor-II gene associated with the survival and relapse prediction of breast carcinoma

Objective Recently, we showed the implication of the polymorphism in tumor necrosis factor-alpha (TNF-α) gene in the susceptibility and prognosis of breast carcinoma. TNF-α acts through its receptors: types I and II. The TNFRII, expressed on the haematopoietic cells, is the high affinity receptor involved in mediating the biological effects of TNF-α. We investigated the susceptibility and prognostic implications of the genetic variation in the TNFRII in breast carcinoma. Methods We used the polymerase chain reaction and restriction enzyme digestion to characterize the variation of the TNFRII gene in 300 unrelated Tunisian patients with breast carcinoma and 200 healthy control subjects. Associations of the genetic marker with the rates of the breast carcinoma-specific overall survival and the disease-free survival were assessed. Results A significant association was found between TNFRII-196 M/R heterozygous genotype and breast carcinoma (OR = 1.61; P = 0.02). This association was more significant in post-menopausal patients (OR = 2.41, P = 0.0001). The 196 R-TNFRII allele showed a significant association with increased overall survival and disease-free survival in breast carcinoma patients. Conclusion Genetic variation in TNFRII may predict the late onset of breast carcinoma, relapse and death for patients with breast carcinoma.

Relationship between the tumor necrosis factor receptor II ( TNF-RII) gene polymorphism and sTNF-RII plasma levels in healthy controls and in rheumatoid arthritis

To assess the relationship between tumor necrosis factor receptor II (TNF-RII) gene polymorphisms and sTNFRII plasma levels in healthy blood donors (HBDs) and in rheumatoid arthritis (RA) patients. 113 HBDs and 49 RA patients were genotyped for the T/G polymorphism in exon 6 of the TNF-RII gene. In the same cases, sTNF-RII plasma levels were determined by an enzyme-linked immunosorbent assay (ELISA) procedure. sTNF-RII levels were higher in RA patients than in HBDs (p < 0.0001). No difference in sTNF-RII levels arose between RA patients on low oral doses of glucocorticoids versus those not taking glucocorticoids. In healthy controls, we observed lower levels of the sTNF-RII in carriers of the TT genotype compared to TG/GG genotype (p = 0.04). In RA there was the same behaviour between TT and TG/GG carriers, even though the difference was not statistically significant. When analyzing the correlation between sTNF-RII plasma levels and disease activity parameters, significant correlations were seen with disease activity score (r = 0.40, p = 0.01), swollen joint count (r = 0.38, p = 0.01), and tender joint count (r = 0.42, p = 0.01), but not with erythrocyte sedimentation rate (r = 0.22, p = ns) nor with C-reactive protein (r = 0.14, p = NS). The correlation remained significant only in the RA subgroup carrying the TT genotype. Healthy donors carrying the TT genotype showed lower sTNF-RII plasma levels than carriers of the TG/GG genotypes, while in RA patients we observed only a trend.

Polymorphism of interleukin-10 promoter and tumor necrosis factor receptor II in Vietnamese patients with systemic lupus erythematosus

The polymorphism of the interleukin-10 (IL-10) promoter and tumor necrosis factor receptor II (TNFRII) in Vietnamese patients with systemic lupus erythematosus (SLE) was examined by using the polymerase chain reaction (PCR) method with genomic DNA and allele-specific primers. In the frequency of IL-10 promoter 1082 genotypes consisting of AA, A/G and GG, the allele frequency of G in the SLE patients was significantly higher than that in the healthy controls. On the other hand, there was no statistical difference in the frequency of TNF receptor (TNFR) II 196 genotypes between the SLE patients and healthy controls. It was therefore suggested that the polymorphism of the IL-10 promoter, but not TNFRII, might participate in the pathogenesis of SLE in Vietnamese.

Molecular study on chicken tumor necrosis factor receptor-II and tumor necrosis factor receptor-associated factor-5.

Tumor necrosis factor (TNF) receptor-associated factors (TRAFs) were identified as signal transducers for the tumor necrosis factor receptor (TNFR) superfamily. In this study, we cloned and characterized two genes that encode chicken TNFR-II and TRAF5. The initial cDNA fragments were obtained by suppressive subtractive hybridization (SSH) of chicken spleen cells with or without lipopolysaccharide stimulation (Salmonella typhimurium SL1181 (RE-mutant)). The results showed that chicken TNFR-II is 1518 bp in length with an open reading frame (ORF) of 1386 bp having 31% homology with human TNFR-II. Expression analysis of chicken TNFR-II revealed that it is highly expressed in the spleen and bursa of Fabricius. The chicken cell lines IN24, MSB1 and 1104B express TNFR-II abundantly. The time course analysis of expression in spleen, bursa of Fabricius and IN24 cell line showed that TNFR-II is maximally expressed at 6 h after stimulation in bursa of Fabricius and after 8 h stimulation in the IN24 cell line. With regard to TRAF5, the complete sequence was 1936 bp in length with an ORF of 1671 bp that showed 71.3% homology with human TRAF5. Expression analysis showed that, among the tissues examined, TRAF5 was strongly expressed in spleen and bursa of Fabricius, while among the cell lines examined, it was maximally expressed in IN24. Thus, both genes were expressed in the same tissues and cell line among examined materials. These results suggest that chicken TNFR-II may interact with TRAF5 adaptor protein to complete its signal transduction pathway.

Regulation of TCR-mediated T cell activation by TNF-RII.

In the present study, we investigated the role of tumor necrosis factor receptor II (TNF-RII) in human T cell activation induced via the T cell receptor (TCR) in an antigen-presenting cell-independent system. Our results confirm that interaction of TNF-alpha with TNF-RII but not TNF-RI is directly costimulatory to TCR-mediated T cell activation, thereby augmenting T cell proliferation, expression of T cell activation markers (CD25, human leukocyte antigen-DR, TNF-RII), and secretion of cytokines such as interferon-gamma and TNF-alpha. In contrast to the well-defined costimulatory molecule CD28, costimulation via TNF-RII showed significant differences in kinetics, requirement for cross-linking, redundancy of intracellular signaling pathways involved, and the capacity to induce interleukin (IL)-2, IL-10, and IL-13 secretion. In addition, cross-linking TNF-RII had the capacity to down-regulate TCR/CD28-induced Ca++ mobilization, IL-2 mRNA expression, and IL-2 and IL-10 secretion. Taken together, our findings demonstrate that TNF-RII plays a unique role among the T cell costimulatory molecules, as TNF-RII ligation can have positive and negative effects on TCR-dependent signaling. TNF-RII cross-linking has an inhibitory effect on early TCR signaling events proximal to induction of Ca++ flux, which ultimately leads to modulation of the T cell cytokine pattern expressed.

Plasma PAI-1 levels are more strongly related to liver steatosis than to adipose tissue accumulation.

Because obesity and insulin resistance (IR) are strongly associated with liver steatosis (LS), we investigated the relation between the degree of LS and plasminogen activator inhibitor-1 (PAI-1) in ob/ob mice, in C57/BL6 mice with alcoholic LS, and in severely obese humans. In both mouse models, plasma PAI-1 levels were associated with PAI-1 expression in the liver and with the degree of LS. Liver PAI-1 antigen was associated with the tumor necrosis factor receptor-II (TNFRII) antigen, whereas association with TNF antigen content was found in ob/ob mice only. No significant correlation between plasma PAI-1 and PAI-1 expression in adipose tissue of ob/ob mice was observed. Furthermore, the relation between plasma PAI-1 levels and body weight was positive in ob/ob mice but negative in C57/BL6 mice (both P<0.001). In humans, PAI-1 levels were correlated with the degree of LS, and 26% of plasma PAI-1 activity was independently explained by LS and serum insulin levels. Plasma PAI-1 levels are more closely related to fat accumulation and PAI-1 expression in the liver than in adipose tissue. In steatotic liver, PAI-1 antigen content is associated with those of TNF and TNFRII. Therefore, we suggest that TNF pathway dysregulation in LS could be involved in increased plasma PAI-1 in obesity with IR.