Elevated soluble death receptor 5 can predict poor prognosis in patients with acute respiratory distress syndrome.

BACKGROUND: The tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) and its receptor, death receptor 5 (DR5), participate in pulmonary cell apoptosis. This study aimed to investigate the clinical value of soluble DR5 and TRAIL for prognosis assessment in acute respiratory distress syndrome (ARDS). RESEARCH DESIGN AND METHODS: Serum and bronchoalveolar lavage fluid (BALF) samples were collected from ARDS patients and controls. Patients were followed-up until death or discharge. Soluble DR5, TRAIL, TNF-α, soluble receptor for advanced glycation end-products (sRAGE), and albumin levels were measured using the Magnetic Luminex or enzyme-linked immunosorbent assays. Data were analyzed according to their distributions and statistical purposes. RESULTS: Serum and BALF DR5 levels were elevated in patients with ARDS; TRAIL elevation and reduction was observed in BALF and serum, respectively. Serum DR5 was higher in non-survivors compared to survivors. Serum DR5 was positively correlated with serum TNF-α and critical illness scores and negatively correlated with serum TRAIL. Serum DR5 exhibited potential for predicting mortality in patients with ARDS. CONCLUSIONS: Serum soluble DR5 elevation, a valuable prognosis predictor in ARDS, may be associated with alveolar epithelial cell apoptosis. TRIAL REGISTRATION: http://www.chictr.org.cn/index.aspx.Uniqueidentifier:ChiCTR-DDD-17013370.

Use of proteomics to identify biomarkers associated with chronic kidney disease and long-term outcomes in patients with myocardial infarction.

BACKGROUND: Patients with chronic kidney disease (CKD) have poor outcomes following myocardial infarction (MI). We performed an untargeted examination of 175 biomarkers to identify those with the strongest association with CKD and to examine the association of those biomarkers with long-term outcomes. METHODS: A total of 175 different biomarkers from MI patients enrolled in the Swedish Web-System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies (SWEDEHEART) registry were analysed either by a multiple reaction monitoring mass spectrometry assay or by a multiplex assay (proximity extension assay). Random forests statistical models were used to assess the predictor importance of biomarkers, CKD and outcomes. RESULTS: A total of 1098 MI patients with a median estimated glomerular filtration rate of 85 mL min-1 /1.73 m2 were followed for a median of 3.2 years. The random forests analyses, without and with adjustment for differences in demography, comorbidities and severity of disease, identified six biomarkers (adrenomedullin, TNF receptor-1, adipocyte fatty acid-binding protein-4, TNF-related apoptosis-inducing ligand receptor 2, growth differentiation factor-15 and TNF receptor-2) to be strongly associated with CKD. All six biomarkers were also amongst the 15 strongest predictors for death, and four of them were amongst the strongest predictors of subsequent MI and heart failure hospitalization. CONCLUSION: In patients with MI, a proteomic approach could identify six biomarkers that best predicted CKD. These biomarkers were also amongst the most important predictors of long-term outcomes. Thus, these biomarkers indicate underlying mechanisms that may contribute to the poor prognosis seen in patients with MI and CKD.

Correlations Between Serum Decoy Receptor 3 and Airflow Limitation and Quality of Life in Male Patients with Stable Stage and Acute Exacerbation of COPD.

PURPOSE: Serum decoy receptor 3 (DcR3) level increases in chronic inflammatory diseases. The present study aimed to examine serum DcR3 and IL-6 levels in male patients with stable chronic obstructive pulmonary disease (COPD) and acute exacerbation of the disease and correlations between these markers and airflow limitation. METHODS: We measured serum DcR3 and IL-6 levels in 60 COPD patients [30 stable COPD (SCOPD), and 30 acute exacerbation of COPD (AECOPD)], and 30 control subjects and assessed their correlations with airflow limitation according to the COPD stage indicated by the global initiative for chronic obstructive pulmonary disease (GOLD) criteria, peripheral O2 saturation (SpO2), and COPD assessment test (CAT) score. We also tested associations between serum DcR3 levels and COPD patients' clinical parameters. RESULTS: Both serum DcR3 and IL-6 levels increased with increasing severity of airflow limitation in SCOPD and AECOPD groups (P < 0.01 to 0.001). These markers also increased in patients with AECOPD compared with subjects in SCOPD group in GOLD stages III-IV (P < 0.05 to 0.001). In addition, there was a significant positive correlation between serum DcR3 level and IL-6, CAT score and smoking history (per year). CONCLUSION: The study revealed that serum DcR3 level elevated with increasing severity of airflow limitation in male COPD patients, particularly in acute exacerbation phase. This increase was associated with a reduced quality of life and increased severity of hypoxia. These results suggest that DcR3 may be associated with the underlying pathophysiology of COPD in male patients.

TNF-Related Apoptosis-Inducing Ligand Receptor 1 in Patients With Ankylosing Spondylitis.

OBJECTIVES: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) belongs to the tumor necrosis factor (TNF) superfamily and is reported to play a role in autoimmune diseases. In this study, we aimed to measure serum TRAIL receptor 1 (TRAIL-R1) concentration and assess any phenotypic relationship in patients with ankylosing spondylitis (AS). METHODS: Fifty-three patients with AS were recruited from August 2014 to December 2014 cross-sectionally. Fifty-three sex- and age-matched healthy controls were also recruited. Serum TRAIL-R1 concentrations were measured using an enzyme-linked immunosorbent assay. The association between serum TRAIL-R1, TNF-α, disease activity indices, markers of systemic inflammation, and clinical features were evaluated. RESULTS: Serum TRAIL-R1 and TNF-α levels were increased in patients with AS compared with healthy controls (4.5 ± 2.3 vs 3.5 ± 2.3 pg/mL, p = 0.036; 3.8 [1.6-7.7] vs 2.0 [0.21-5.7] pg/mL, p = 0.048, respectively). Serum TRAIL-R1 displayed a medium positive correlation with serum TNF-α concentrations (r = 0.412; p = 0.002). Serum TRAIL-R1 concentration was higher in human leucocyte antigen (HLA)-B27-positive patients compared with non-HLA-B27 patients (5.5 ± 2.2 vs 3.1 ± 1.6 pg/mL, p < 0.001). No relationship was found between serum TRAIL-R1 concentration and disease activity scores. CONCLUSIONS: This study confirms that serum TRAIL-R1 levels are higher in AS patients than healthy controls. The persistence of significantly elevated serum TRAIL-R1 levels, even in patients with low disease activity or after excluding biologic treatment, and the association with HLA-B27 positivity, warrants further investigation due to the unclear role of TRAIL-R1 in the pathophysiology of AS.

sTRAIL-R2 (Soluble TNF [Tumor Necrosis Factor]-Related Apoptosis-Inducing Ligand Receptor 2) a Marker of Plaque Cell Apoptosis and Cardiovascular Events.

Background and Purpose- Cellular apoptosis is an important feature in atherosclerosis, contributing to necrotic core formation, and plaque vulnerability. Activation of the death receptor TRAIL-R2 (TNF [tumor necrosis factor]-related apoptosis-inducing ligand receptor 2) through its ligand tumor necrosis factor-relate apoptosis-inducing ligand (TRAIL), induces apoptosis in cells in vitro. sTRAIL-R2 (soluble TRAIL-R2) was recently shown to predict cardiovascular events in healthy individuals. In the present study, we explored if plaque levels of sTRAIL-R2 and sTRAIL reflect plaque apoptosis and vulnerability and if plasma levels of these markers predict future events in subjects with advanced atherosclerosis. Methods- Plasma from 558 patients and 202 carotid plaques from the Carotid Plaque Imaging Project biobank were used. sTRAIL-R2, sTRAIL, and caspase-8 levels were assessed using a Proseek Multiplex CVD96×96 assay. Active caspase-3 was measured using ELISA to assess plaque apoptosis. Plaque morphology was studied by immunohistochemistry. Inflammatory cytokines were assessed by Luminex. mRNA levels were quantified by RNA sequencing. Monocytes, T cells, B cells, and human coronary artery smooth muscle cells were used to study sTRAIL-R2 and sTRAIL release on cell apoptosis and inflammatory stimuli in vitro. Results- Plaque levels of sTRAIL-R2 and sTRAIL correlated to markers of extrinsic induced apoptosis (caspase-3 and -8). sTRAIL-R2 and sTRAIL protein expression were increased in symptomatic carotid plaques and patients with higher plasma levels of sTRAIL-R2 had a higher risk of future cardiovascular events. sTRAIL-R2 and sTRAIL were released upon activation of the extrinsic apoptosis pathway in vitro. sTRAIL-R2 and sTRAIL correlated with inflammatory cytokines, to CD68 expression and inversely to α-actin in the plaque tissue. Conclusions- The present study shows that sTRAIL-R2 and sTRAIL are associated to human plaque cell apoptosis, plaque inflammatory activity, and with symptomatic carotid plaques. Furthermore, high plasma levels of sTRAIL-R2 in plasma predict, independently, future cardiovascular events in individuals with manifest atherosclerotic disease.

Prognostic significance of serum soluble DR5 levels in small-cell lung cancer.

The death receptor 5 (DR5) is a member of the tumor necrosis factor receptor superfamily that can transduce the apoptosis signal in cells. This study assessed serum levels of soluble death receptor 5 (sDR5) in small-cell lung cancer (SCLC) patients compared with those in healthy controls. Clinicopathological features of patients, treatment responses, and overall survival of patients were also recorded and analyzed. The sDR5 levels were analyzed using ELISA in 50 healthy controls and 82 SCLC patients before and after first-line chemotherapy. The statistical data showed that pre-treatment levels of serum sDR5 in SCLC patients were higher than those of healthy controls (P<0.001). Pre-treatment levels of serum sDR5 were significantly associated with smoking history of patients, Veterans Administration Lung Study Group (VALSG) stage, tumor size, and lymph node (N) metastasis (P=0.028, 0.001, 0.028, and 0.01, respectively). After treatment with the first-line chemotherapy, the post-treatment levels of serum sDR5 were obviously decreased (P<0.001), and correlated with treatment responses (P<0.001), although there was no significant difference in their pretreatment sDR5 levels (P=0.62). Cox proportional hazard analysis demonstrated that the post-treatment levels of serum sDR5, VALSG stage, and PS status were all independent predictors for overall survival of patients. The results from the current study indicate that serum level of sDR5 could be further confirmed as a biomarker to predict treatment responses and survival of SCLC patients.

Cardiovascular disease in systemic lupus erythematosus is associated with increased levels of biomarkers reflecting receptor-activated apoptosis.

BACKGROUND AND AIMS: There is convincing evidence that adaptive immune responses affect the development of atherosclerosis and thrombosis and several autoimmune diseases are associated with increased cardiovascular risk. However, our understanding of the underlying mechanisms remains limited. We investigated how biomarkers reflecting four aspects of autoimmunity: apoptosis, inflammation, tissue degradation and repair, associate with cardiovascular disease (CVD) in subjects with systemic lupus erythematosus (SLE). METHODS: We investigated 484 well-characterized SLE patients, 69 of whom had CVD (coronary artery disease, cerebrovascular disease or peripheral artery disease), and 253 controls. Occurrence of carotid plaques was investigated with ultrasound. Plasma levels of biomarkers reflecting apoptosis (Fas, TNF receptor 1, TRAIL receptor 2), inflammation (IL-6, IL-8, monocyte chemotactic protein-1), tissue degradation (matrix metalloproteinase (MMP)-1, MMP-3, MMP-7), and tissue repair (platelet-derived growth factor, epidermal growth factor and stem cell factor) were analyzed by Proximity Extension Assay. RESULTS: Subjects with SLE had markedly elevated plasma levels of biomarkers reflecting apoptosis, inflammation and tissue degradation as compared to controls. SLE patients with CVD had higher levels of Fas, TNF receptor 1, TRAIL receptor 2, MMP-1 and -7 than those without CVD. The same associations were found for the presence of a carotid plaque. When controlling for the factors included in the Framingham risk score, all biomarkers except MMP-1 remained associated with the presence of a carotid plaque, while only TRAIL receptor 2 levels remained significantly associated with CVD. CONCLUSIONS: Our findings argue that the cardiovascular risk in SLE is associated with increased cell death by apoptosis and tissue degradation.

GDF-15 and TRAIL-R2 are powerful predictors of long-term mortality in patients with acute myocardial infarction.

Background The Proximity Extension Assay proteomics chip provides a large-scale analysis of 92 biomarkers linked to cardiovascular disease or inflammation. We aimed to identify the biomarkers that best predicted long-term all-cause mortality in patients with acute myocardial infarction. Methods In this prospective cohort study, 92 biomarkers were analysed in 847 consecutive patients from the Västmanland Myocardial Infarction Study with a median follow-up of 6.9 years. Results The mean (± standard deviation) age of the patients was 70 (11.8) years and 32.7% were female. Two hundred and seven patients had died after follow-up. The biomarkers most strongly linked to all-cause mortality were growth differentiation factor 15 (GDF-15) and tumour necrosis factor-related apoptosis-inducing ligand receptor 2 (TRAIL-R2). Cox regression analysis showed that GDF-15 (hazard ratio 1.25 per unit change, 95% confidence interval, 1.02-1.53, p = 0.031) and TRAIL-R2 (hazard ratio 1.37 per unit change, 95% confidence interval 1.12-1.67, p = 0.002) were independent predictors of long-term all-cause mortality after adjusting for age, gender, diabetes, previous myocardial infarction, stroke, heart failure, hypertension, smoking, hypercholesterolaemia, body mass index, ST-elevation myocardial infarction, left ventricular ejection fraction, troponin I, estimated glomerular filtration rate, N-terminal pro-brain natriuretic peptide and C-reactive protein. The combination of GDF-15 and TRAIL-R2 with established risk factors and biomarkers showed a discriminating accuracy of separating survivors from non-survivors with a cross-validated area under the receiving operating characteristics curve of 0.88 within five years. Conclusion GDF-15 and TRAIL-R2 were the most powerful Proximity Extension Assay chip biomarkers in predicting long-term all-cause mortality in patients with acute myocardial infarction.

TRAIL in CD8+ T cells from patients with severe aplastic anemia.

Severe aplastic anemia (SAA) is an autoimmune disease caused mainly by activated T lymphocytes. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a member of TNF family, which can induce apoptosis and play a significant role in the pathogenesis of many autoimmune disorders. In this study, we sought to investigate the role of TRAIL in peripheral CD8+ T cells (CTLs) from SAA patients to clarify the autoimmune mechanisms of bone marrow failure in SAA. The expression of TRAIL and TRAIL-R2 in CTLs from SAA patients and normal controls were determined by flow cytometry, real-time PCR, and western blot. Expression of perforin and granzyme B and apoptosis in CTLs were evaluated by flow cytometry. The expression of TRAIL and TRAIL-R2 in SAA patients was significantly decreased compared with controls; however, there was no statistical difference in TRAIL mRNA expression between the two groups. TRAIL expression in CTLs was negatively correlated with the expression of perforin and granzyme B, and negatively correlated with CTLs apoptosis in SAA patients. The TRAIL pathway may be responsible for abnormal CTL activation in SAA patients. Further study of TRAIL and its receptors may elucidate the pathogenesis of SAA.

Decreased placental and maternal serum TRAIL-R2 levels are associated with placenta accreta.

OBJECTIVES: TNF-related apoptosis-inducing ligand receptor-2 (TRAIL-R2) is produced both by decidual and trophoblast cells during pregnancy and known to participate in apoptosis. In this study, we aimed to determine and to compare maternal serum and placental TRAIL-R2 levels in patients with placenta accreta, non-adherent placenta previa and in healthy pregnancies. We also aimed to analyze the association of placenta accreta with the occurrence of previous C-sections. STUDY DESIGN: A total of 82 pregnant women were enrolled in this case-control study (27 placenta accreta patients, 26 non-adherent placenta previa patients and 29 age-, and BMI-matched healthy, uncomplicated pregnant controls). TRAIL-R2 levels were studied in both maternal serum and placental tissue homogenates. Determining the best predictor(s) which discriminate placenta accreta was analyzed by multiple logistic regression analyses. Adjusted odds ratios and 95% confidence intervals were also calculated. RESULTS: Both placental and serum TRAIL-R2 levels were significantly lower in placenta accreta group (median 34.82 pg/mg and 19.85 pg/mL, respectively) when compared with both non-adherent placenta previa (median 39.24 pg/mg and 25.99 pg/mL, respectively) and the control groups (median 41.62 pg/mg and 25.87 pg/mL, respectively) (p < 0.05). Placental TRAIL-R2 levels and previous cesarean section were found to be significantly associated with placenta accreta (OR: 0.934 95% CI 0.883-0.987, p = 0.016 and OR:7.725 95% CI: 2.717-21.965, p < 0.001, respectively). Placental and serum TRAIL-R2 levels were positively correlated. CONCLUSION: Decreased levels of placental TRAIL-R2 and previous history of cesarean section were found to be significantly associated with placenta accreta, suggesting a possible role of apoptosis in abnormal trophoblast invasion.

TRAIL and TRAIL receptors splice variants during long-term interferon ß treatment of patients with multiple sclerosis: evaluation as biomarkers for therapeutic response.

OBJECTIVE: We aimed to assess the effects of interferon ß (IFNß) treatment on the expression of the splice variants of the Tumour necrosis factor-Related Apoptosis Inducing Ligand (TRAIL) and its receptors in different cell subpopulations (CD14+, CD4+ and CD8+) from patients with multiple sclerosis (MS), and to determine whether this expression discriminated responders from non-responders to IFNß therapy. METHODS: We examined mRNA expression of the TRAIL and TRAIL receptors variants in patients with MS, at baseline and after one year of IFNß therapy, according to responsiveness to this drug. RESULTS: Long-term therapy with IFNß increased the expression of TRAIL-α in T cell subsets exclusively from responders and decreased the expression of the isoform 2 of TRAILR-2 in monocytes from responders as well as non-responders. Lower expression of TRAIL-α, and higher expression of TRAIL-ß in monocytes and T cells, was found before the onset of IFNß therapy in patients who will subsequently become responders. Baseline expression of TRAILR-1 was also significantly higher in monocytes and CD4+ T cells from responders. CONCLUSIONS: The present study shows that long-term IFNß treatment has a direct influence on TRAIL-α and TRAILR-2 isoform 2 expression. Besides, receiver operating characteristic analysis revealed that the baseline expression of TRAIL-α in monocytes and T cells, and that of TRAILR-1 in monocytes and CD4+ T cells, showed a predictive value of the clinical response to IFNß therapy, pointing to a role of TRAIL system in the mechanism of action of IFNß in MS that will need further investigation.

Increased serum TRAIL and DR5 levels correlated with lung function and inflammation in stable COPD patients.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is associated with abnormal systemic inflammation, and apoptosis is one of the pathogenic mechanisms of COPD. Several studies have suggested that tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and its receptors were not only involved in diseases associated with apoptosis but also in inflammatory diseases. However, limited data about the possible relationship between COPD and TRAIL/TRAIL-receptors are available. OBJECTIVE: To evaluate the potential relationship between TRAIL/TRAIL-receptors and COPD. METHODS: Serum levels of TRAIL, decoy receptor 5 (DR5), C-reactive protein, and tumor necrosis factor-α were analyzed using multiplex enzyme-linked immunosorbent assay kits. Then, serum levels of TRAIL and DR5 in 57 COPD patients with 35 healthy controls were compared and correlated with lung function and systemic inflammation. RESULTS: Mean levels of serum TRAIL and DR5 were significantly higher in COPD patients than those in controls (50.17±17.70 versus 42.09±15.49 pg/mL, P=0.029; 48.15±22.88 versus 38.94±10.95 pg/mL, P=0.032, respectively). Serum levels of TRAIL and DR5 correlated inversely with forced expiratory volume in 1 second % predicted, an index of lung function in COPD (r=-0.354, P=0.007 for TRAIL; r=-0.394, P=0.002 for DR5) in all participants (r=-0.291, P=0.005 for TRAIL; r=-0.315, P=0.002 for DR5), while DR5 correlated positively with C-reactive protein (r=0.240, P=0.021 for total subjects) and TRAIL correlated positively with tumor necrosis factor-α (r=0.371, P=0.005 for COPD; r=0.349, P=0.001 for total subjects). CONCLUSION: Our results suggested that circulating TRAIL and DR5 increased in COPD patients and were associated with lung function and systemic inflammation in COPD. Future studies are needed to verify whether and how TRAIL and its receptors play roles in COPD.

Association of TRAIL and Its Receptors with Large-Artery Atherosclerotic Stroke.

OBJECTIVE: To investigate the association of the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and its receptors, osteoprotegerin (OPG) and death receptor 5 (DR5) with large-artery atherosclerosis (LAA) stroke and its prognosis. METHODS: We included patients with LAA stroke (n = 132) according to the TOAST classification system and controls (n = 60). To evaluate the extent and severity of cerebral atherosclerosis, the LAA stroke group was subdivided into 3 subgroups by number of cerebral arteries with atherosclerotic stenosis (≥50%): single, double and multiple (≥3). Plasma levels of TRAIL, OPG and DR5 were measured by ELISA. Ordinal logistic regression was used to analyze the association between the plasma levels of TRAIL, OPG, DR5 and the severity of cerebral atherosclerosis. Prognosis was determined by the Modified Rankin Scale at 3 months after stroke. Receiver operating characteristic (ROC) curve was used to evaluated TRAIL as a predictor of prognosis. RESULTS: Plasma TRAIL level was significantly lower for LAA patients than controls (P<0.001), while plasma OPG and DR5 levels were higher (both P<0.001). Logistic regression analysis revealed that risk of severe cerebral atherosclerosis was reduced significantly with increased plasma level of TRAIL (OR 0.438; 95% CI 0.282-0.681; P<0.001), whereas increased with high plasma levels of OPG and DR5 (OR 2.707; 95% CI 1.702-4.302, P <0.001; OR 3.593; 95% CI 1.878-6.869, P <0.001). Plasma TRAIL level was negatively correlated with the prognosis (r = - 0.372, P <0.001). The optimal cut-off value of TRAIL for prognosis was 848.63 pg/mL. The sensitivity and specificity at this cut-off value were 63.1% and 86.2%, respectively. After adding the plasma TRAIL level into the multivariate model of ROC, the area under the ROC curve was increased from 0.639 to 0.785, but the change was not statistical significant (P = 0.146). CONCLUSIONS: TRAIL and its receptors OPG and DR5 may be involved in LAA stroke and the plasma level of TRAIL may be a biomarker predicting the severity of cerebral atherosclerosis and the prognosis of LAA stroke.

Simian Immunodeficiency Virus Infection of Chimpanzees (Pan troglodytes) Shares Features of Both Pathogenic and Non-pathogenic Lentiviral Infections.

The virus-host relationship in simian immunodeficiency virus (SIV) infected chimpanzees is thought to be different from that found in other SIV infected African primates. However, studies of captive SIVcpz infected chimpanzees are limited. Previously, the natural SIVcpz infection of one chimpanzee, and the experimental infection of six chimpanzees was reported, with limited follow-up. Here, we present a long-term study of these seven animals, with a retrospective re-examination of the early stages of infection. The only clinical signs consistent with AIDS or AIDS associated disease was thrombocytopenia in two cases, associated with the development of anti-platelet antibodies. However, compared to uninfected and HIV-1 infected animals, SIVcpz infected animals had significantly lower levels of peripheral blood CD4+ T-cells. Despite this, levels of T-cell activation in chronic infection were not significantly elevated. In addition, while plasma levels of ß2 microglobulin, neopterin and soluble TNF-related apoptosis inducing ligand (sTRAIL) were elevated in acute infection, these markers returned to near-normal levels in chronic infection, reminiscent of immune activation patterns in 'natural host' species. Furthermore, plasma soluble CD14 was not elevated in chronic infection. However, examination of the secondary lymphoid environment revealed persistent changes to the lymphoid structure, including follicular hyperplasia in SIVcpz infected animals. In addition, both SIV and HIV-1 infected chimpanzees showed increased levels of deposition of collagen and increased levels of Mx1 expression in the T-cell zones of the lymph node. The outcome of SIVcpz infection of captive chimpanzees therefore shares features of both non-pathogenic and pathogenic lentivirus infections.

Genetic variants in the tumor necrosis factor-related apoptosis-inducing ligand and death receptor genes contribute to susceptibility to bladder cancer.

AIM: The aim of this study was to evaluate the role of polymorphisms of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and death receptor (DR4) genes in bladder cancer susceptibility in a Turkish population. MATERIALS AND METHODS: The study group included 91 bladder cancer patients, while the control group comprised 139 individuals with no evidence of malignancy. Gene polymorphisms of TRAIL C1595T (rs1131580) and DR4 C626G (rs4871857) were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. RESULTS: The frequency of the TRAIL 1595 TT genotype was significantly lower in patients with bladder cancer compared to controls (p<0.001; odds ratios [OR]=0.143; 95% confidence interval [CI]=0.045-0.454). A significantly increased risk for developing bladder cancer was found for the group bearing a C allele for TRAIL C1595T polymorphism (p<0.001; OR=1.256; 95% CI=1.138-1.386). The observed genotype and allele frequencies of DR4 626 C/G in all groups were in agreement with the Hardy-Weinberg equilibrium (p=0.540). However, the frequency of DR4 GG genotype was found to be 2.1-fold increased in the bladder cancer patients with high-grade tumor, when compared to those having low-grade tumor (p=0.036). Additionally, combined genotype analysis showed that the frequency of TRAILCT-DR4GG was significantly higher in patients with bladder cancer in comparison with those of controls (p=0.037; OR=2.240; 95% CI=1.138-1.386). CONCLUSIONS: Our study provides new evidence that TRAIL 1595 C allele may be used as a low-penetrant risk factor for bladder cancer development in a Turkish population. Otherwise, gene-gene interaction analysis revealed that the DR4GG genotype may have a predominant effect on the increased risk of bladder cancer over the TRAIL CT genotype.

Antibody-free LC-MS/MS quantification of rhTRAIL in human and mouse serum.

The major challenge in targeted protein quantification by LC-MS/MS in serum lies in the complexity of the biological matrix with regard to the wide diversity of proteins and their extremely large dynamic concentration range. In this study, an LC-MS/MS method was developed for the simultaneous quantification of the 60-kDa biopharmaceutical proteins recombinant human tumor necrosis factor-related apoptosis-inducing ligand wild type (rhTRAIL(WT)) and its death receptor 4 (DR4)-specific variant rhTRAIL(4C7) in human and mouse serum. Selective enrichment of TRAIL was accomplished by immobilized metal affinity chromatography (IMAC), which was followed by tryptic digestion of the enriched sample and quantification of a suitable signature peptide. For absolute quantification, (15)N-metabolically labeled internal standards of rhTRAIL(WT) and rhTRAIL(4C7) were used. Since the signature peptides that provided the highest sensitivity and allowed discrimination between rhTRAIL(WT) and rhTRAIL(4C7) contained methionine residues, we oxidized these quantitatively to their sulfoxides by the addition of 0.25% (w/w) hydrogen peroxide. The final method has a lower limit of quantification of 20 ng/mL (ca. 350 pM) and was fully validated according to current international guidelines for bioanalysis. To show the applicability of the LC-MS/MS method for pharmacokinetic studies, we quantified rhTRAIL(WT) and rhTRAIL(4C7) simultaneously in serum from mice injected intraperitoneally at a dose of 5 mg/kg for each protein. This is the first time that two variants of rhTRAIL differing by only a few amino acids have been analyzed simultaneously in serum, an approach that is not possible by conventional enzyme-linked immuno-sorbent assay (ELISA) analysis.

Serum soluble death receptor 5 concentration in patients with chronic hepatitis B is associated with liver damage and viral antigen level.

OBJECTIVES: To measure the levels of serum soluble death receptor 5 (sDR5) in patients with hepatitis B. DESIGN AND METHODS: sDR5 concentration in 60 HBV infected patients and 30 healthy volunteers were measured by ELISA. RESULTS: sDR5 concentration in the HBV infected patients was decreased and correlated with serum ALT, Tbil level, albumin/globulin ratio and HBV antigen level. CONCLUSIONS: Decreased serum sDR5 is associated with high level of liver damage and inhibited HBV antigen expression.

Association between endometriosis and polymorphisms in tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), TRAIL receptor and osteoprotegerin genes and their serum levels.

PURPOSE: To evaluate the relationship between endometriosis and polymorphisms in the genes encoding tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), TRAIL receptor (DR) and osteoprotegerin (OPG) and their serum levels in Korean women. METHODS: A case-control study was conducted with 138 women with endometriosis and 214 women without endometriosis in academic medical center. TRAIL c.49G>A, c.592A>G, c.615A>G, and c.662T>C; DR4 c.626G>C and c.1322A>G; DR5 c.95C>T, c.200C>T, and c.72T>G; OPG -245T>G, c.9C>G, c.788A>C, and c.9938G>T polymorphisms were investigated and circulating levels of TRAIL and OPG were measured. RESULTS: The TRAIL c.49G>A, c.615A>G, and c.662T>C; the DR4 c.626G>C; the DR5 c.72T>G; the OPG c.788A>C and c.9938G>T polymorphisms were not observed. The genotype distributions and allele frequencies of single or combined polymorphisms of TRAIL, DR4, DR5, and OPG measured in women with endometriosis were not different from those in women without endometriosis, regardless of endometriosis stage. Serum TRAIL and OPG levels were significantly lower in women with endometriosis than in women without endometriosis, but these levels did not show differences between early and advanced endometriosis. CONCLUSIONS: Endometriosis is associated with circulating TRAIL and OPG levels in Korean women but not with the TRAIL, DR, and OPG polymorphisms.

Isolation of a TRAIL antagonist from the serum of HIV-infected patients.

Virus-host interactions are characterized by the selection of adaptive mechanisms by which to evade pathogenic and defense mechanisms, respectively. In primary T cells infected with HIV, HIV infection up-regulates TNF-related apoptosis inducing ligand (TRAIL) and death-inducing TRAIL receptors, but blockade of TRAIL:TRAIL receptor interaction does not alter HIV-induced cell death. Instead, HIV infection results in a novel splice variant that we call TRAIL-short (TRAIL-s), which antagonizes TRAIL-R2. In HIV patients, plasma TRAIL-s concentration increases with increasing viral load and renders cells resistant to TRAIL-induced death. Knockdown of TRAIL-s abrogates this resistance. We propose that TRAIL-s is a novel adaptive mechanism of apoptosis resistance acquired by HIV-infected cells to avoid their elimination by TRAIL-dependent effector mechanism.