A Novel Mechanism of TRAF Signaling Revealed by Structural and Functional Analyses of the TRADD–TRAF2 Interaction

AbstractTRAF proteins are major mediators for the cell activation, cell survival, and antiapoptotic functions of the TNF receptor superfamily. They can be recruited to activated TNF receptors either by direct interactions with the receptors or indirectly via the adaptor protein TRADD. We now report the structure of the TRADD-TRAF2 complex, which is highly distinct from receptor–TRAF2 interactions. This interaction is significantly stronger and we show by an in vivo signaling assay that TRAF2 signaling is more readily initiated by TRADD than by direct receptor–TRAF2 interactions. TRADD is specific for TRAF1 and TRAF2, which ensures the recruitment of cIAPs for the direct inhibition of caspase activation in the signaling complex. The stronger affinity and unique specificity of the TRADD–TRAF2 interaction are crucial for the suppression of apoptosis and provide a mechanistic basis for the perturbation of TRAF recruitment in sensitizing cell death induction

5-Fluorouracil targets thymidylate synthase in the selective suppression of TH17 cell differentiation

While it is well established that treatment of cancer patients with 5-Fluorouracil (5-FU) can result in immune suppression, the exact function of 5-FU in the modulation of immune cells has not been fully established. We found that low dose 5-FU selectively suppresses TH17 and TH1 cell differentiation without apparent effect on Treg, TH2, and significantly suppresses thymidylate synthase (TS) expression in TH17 and TH1 cells but has a lesser effect in tumor cells and macrophages. Interestingly, the basal expression of TS varies significantly between T helper phenotypes and knockdown of TS significantly impairs TH17 and TH1 cell differentiation without affecting the differentiation of either Treg or TH2 cells. Finally, low dose 5-FU is effective in ameliorating colitis development by suppressing TH17 and TH1 cell development in a T cell transfer colitis model. Taken together, the results highlight the importance of the anti-inflammatory functions of low dose 5-FU by selectively suppressing TH17 and TH1 immune responses

Molecular mechanisms controlling synaptic recruitment of GluA4 subunit-containing AMPAreceptors

Synaptic recruitment of AMPA receptors (AMPARs) represents a key postsynaptic mechanism driving functional development and maturation of glutamatergic synapses. At immature hippocampal synapses, PKA-driven synaptic insertion of GluA4 is the predominant mechanism for synaptic reinforcement. However, the physiological significance and molecular determinants of this developmentally restricted form of plasticity are not known. Here we show that PKA activation leads to insertion of GluA4 to synaptic sites with initially weak or silent AMPAR-mediated transmission. This effect depends on a novel mechanism involving the extreme C-terminal end of GluA4, which interacts with the membrane proximal region of the C-terminal domain to control GluA4 trafficking. In the absence of GluA4, strengthening of AMPAR-mediated transmission during postnatal development was significantly delayed. These data suggest that the GluA4-mediated activation of silent synapses is a critical mechanism facilitating the functional maturation of glutamatergic circuitry during the critical period of experience-dependent fine-tuning

Hepatitis B virus pre-S deletion mutations are a risk factor for hepatocellular carcinoma: a matched nested case–control study

A matched nested case–control study of 33 paired cases and controls was conducted, based on a study cohort in Long An county, Guangxi, China, to determine whether infection with hepatitis B virus (HBV) with pre-S deletions is independently associated with the development of hepatocellular carcinoma (HCC), without the confounding effects of basal core promoter (BCP) double mutations. The prevalence of pre-S deletions was significantly higher in HCC (45.5 %, 15 of 33) than the controls (18.2 %, 6 of 33) (P<0.01), under the control of the influence of BCP double mutations. Most of the pre-S deletions occurred in, or involved, the 5′ half of the pre-S2 region and the difference between HCC (93.3 %, 14 of 15) and controls (66.7 %, four of six) was significant for this region (P=0.015). There was no significant difference in pre-S deletions between the BCP mutant group and BCP wild-type group (P>0.05), nor was the prevalence of pre-S deletions significantly different between genotypes B and C (P>0.1). These results suggest that pre-S deletions constitute an independent risk factor for HCC and their emergence and effect are independent of BCP mutations. The 5′ terminus of pre-S2 is the favoured site for the deletion mutations, especially in HCC cases. Further prospective studies are required to confirm the role of these mutations in the development of HCC

Anticancer drugs for the modulation of endoplasmic reticulum stress and oxidative stress

Prior research has demonstrated how the endoplasmic reticulum (ER) functions as a multifunctional organelle and as a well-orchestrated protein-folding unit. It consists of sensors which detect stress-induced unfolded/misfolded proteins and it is the place where protein folding is catalyzed with chaperones. During this folding process, an immaculate disulfide bond formation requires an oxidized environment provided by the ER. Protein folding and the generation of reactive oxygen species (ROS) as a protein oxidative byproduct in ER are crosslinked. An ER stress-induced response also mediates the expression of the apoptosis-associated gene C/EBP-homologous protein (CHOP) and death receptor 5 (DR5). ER stress induces the upregulation of tumor necrosis factor-related apoptosis inducing ligand (TRAIL) receptor and opening new horizons for therapeutic research. These findings can be used to maximize TRAIL-induced apoptosis in xenografted mice. This review summarizes the current understanding of the interplay between ER stress and ROS. We also discuss how damage-associated molecular patterns (DAMPs) function as modulators of immunogenic cell death and how natural products and drugs have shown potential in regulating ER stress and ROS in different cancer cell lines. Drugs as inducers and inhibitors of ROS modulation may respectively exert inducible and inhibitory effects on ER stress and unfolded protein response (UPR). Reconceptualization of the molecular crosstalk among ROS modulating effectors, ER stress, and DAMPs will lead to advances in anticancer therapy

Drug interventions for the treatment of obesity in children and adolescents

BACKGROUND: Child and adolescent obesity has increased globally, and can be associated with significant short- and long-term health consequences. OBJECTIVES: To assess the efficacy of drug interventions for the treatment of obesity in children and adolescents. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, PubMed (subsets not available on Ovid), LILACS as well as the trial registers ICTRP (WHO) and ClinicalTrials.gov. Searches were undertaken from inception to March 2016. We checked references and applied no language restrictions. SELECTION CRITERIA: We selected randomised controlled trials (RCTs) of pharmacological interventions for treating obesity (licensed and unlicensed for this indication) in children and adolescents (mean age under 18 years) with or without support of family members, with a minimum of three months' pharmacological intervention and six months' follow-up from baseline. We excluded interventions that specifically dealt with the treatment of eating disorders or type 2 diabetes, or included participants with a secondary or syndromic cause of obesity. In addition, we excluded trials which included growth hormone therapies and pregnant participants. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trial quality and extracted data following standard Cochrane methodology. Where necessary we contacted authors for additional information. MAIN RESULTS: We included 21 trials and identified eight ongoing trials. The included trials evaluated metformin (11 trials), sibutramine (six trials), orlistat (four trials), and one trial arm investigated the combination of metformin and fluoxetine. The ongoing trials evaluated metformin (four trials), topiramate (two trials) and exenatide (two trials). A total of 2484 people participated in the included trials, 1478 participants were randomised to drug intervention and 904 to comparator groups (91 participants took part in two cross-over trials; 11 participants not specified). Eighteen trials used a placebo in the comparator group. Two trials had a cross-over design while the remaining 19 trials were parallel RCTs. The length of the intervention period ranged from 12 weeks to 48 weeks, and the length of follow-up from baseline ranged from six months to 100 weeks.Trials generally had a low risk of bias for random sequence generation, allocation concealment and blinding (participants, personnel and assessors) for subjective and objective outcomes. We judged approximately half of the trials as having a high risk of bias in one or more domain such as selective reporting.The primary outcomes of this review were change in body mass index (BMI), change in weight and adverse events. All 21 trials measured these outcomes. The secondary outcomes were health-related quality of life (only one trial reported results showing no marked differences; very low certainty evidence), body fat distribution (measured in 18 trials), behaviour change (measured in six trials), participants' views of the intervention (not reported), morbidity associated with the intervention (measured in one orlistat trial only reporting more new gallstones following the intervention; very low certainty evidence), all-cause mortality (one suicide in the orlistat intervention group; low certainty evidence) and socioeconomic effects (not reported).Intervention versus comparator for mean difference (MD) in BMI change was -1.3 kg/m(2) (95% confidence interval (CI) -1.9 to -0.8; P < 0.00001; 16 trials; 1884 participants; low certainty evidence). When split by drug type, sibutramine, metformin and orlistat all showed reductions in BMI in favour of the intervention.Intervention versus comparator for change in weight showed a MD of -3.9 kg (95% CI -5.9 to -1.9; P < 0.00001; 11 trials; 1180 participants; low certainty evidence). As with BMI, when the trials were split by drug type, sibutramine, metformin and orlistat all showed reductions in weight in favour of the intervention.Five trials reported serious adverse events: 24/878 (2.7%) participants in the intervention groups versus 8/469 (1.7%) participants in the comparator groups (risk ratio (RR) 1.43, 95% CI 0.63 to 3.25; 1347 participants; low certainty evidence). A total 52/1043 (5.0%) participants in the intervention groups versus 17/621 (2.7%) in the comparator groups discontinued the trial because of adverse events (RR 1.45, 95% CI 0.83 to 2.52; 10 trials; 1664 participants; low certainty evidence). The most common adverse events in orlistat and metformin trials were gastrointestinal (such as diarrhoea, mild abdominal pain or discomfort, fatty stools). The most frequent adverse events in sibutramine trials included tachycardia, constipation and hypertension. The single fluoxetine trial reported dry mouth and loose stools. No trial investigated drug treatment for overweight children. AUTHORS' CONCLUSIONS: This systematic review is part of a series of associated Cochrane reviews on interventions for obese children and adolescents and has shown that pharmacological interventions (metformin, sibutramine, orlistat and fluoxetine) may have small effects in reduction in BMI and bodyweight in obese children and adolescents. However, many of these drugs are not licensed for the treatment of obesity in children and adolescents, or have been withdrawn. Trials were generally of low quality with many having a short or no post-intervention follow-up period and high dropout rates (overall dropout of 25%). Future research should focus on conducting trials with sufficient power and long-term follow-up, to ensure the long-term effects of any pharmacological intervention are comprehensively assessed. Adverse events should be reported in a more standardised manner specifying amongst other things the number of participants experiencing at least one adverse event. The requirement of regulatory authorities (US Food and Drug Administration and European Medicines Agency) for trials of all new medications to be used in children and adolescents should drive an increase in the number of high quality trials

The spin label amino acid TOAC and its uses in studies of peptides: chemical, physicochemical, spectroscopic, and conformational aspects

We review work on the paramagnetic amino acid 2,2,6,6-tetramethyl-N-oxyl-4-amino-4-carboxylic acid, TOAC, and its applications in studies of peptides and peptide synthesis. TOAC was the first spin label probe incorporated in peptides by means of a peptide bond. In view of the rigid character of this cyclic molecule and its attachment to the peptide backbone via a peptide bond, TOAC incorporation has been very useful to analyze backbone dynamics and peptide secondary structure. Many of these studies were performed making use of EPR spectroscopy, but other physical techniques, such as X-ray crystallography, CD, fluorescence, NMR, and FT-IR, have been employed. The use of double-labeled synthetic peptides has allowed the investigation of their secondary structure. A large number of studies have focused on the interaction of peptides, both synthetic and biologically active, with membranes. In the latter case, work has been reported on ligands and fragments of GPCR, host defense peptides, phospholamban, and β-amyloid. EPR studies of macroscopically aligned samples have provided information on the orientation of peptides in membranes. More recent studies have focused on peptide–protein and peptide–nucleic acid interactions. Moreover, TOAC has been shown to be a valuable probe for paramagnetic relaxation enhancement NMR studies of the interaction of labeled peptides with proteins. The growth of the number of TOAC-related publications suggests that this unnatural amino acid will find increasing applications in the future

Canagliflozin and Renal Outcomes in Type 2 Diabetes and Nephropathy

BACKGROUND Type 2 diabetes mellitus is the leading cause of kidney failure worldwide, but few effective long-term treatments are available. In cardiovascular trials of inhibitors of sodium–glucose cotransporter 2 (SGLT2), exploratory results have suggested that such drugs may improve renal outcomes in patients with type 2 diabetes. METHODS In this double-blind, randomized trial, we assigned patients with type 2 diabetes and albuminuric chronic kidney disease to receive canagliflozin, an oral SGLT2 inhibitor, at a dose of 100 mg daily or placebo. All the patients had an estimated glomerular filtration rate (GFR) of 30 to 300 to 5000) and were treated with renin–angiotensin system blockade. The primary outcome was a composite of end-stage kidney disease (dialysis, transplantation, or a sustained estimated GFR of <15 ml per minute per 1.73 m 2), a doubling of the serum creatinine level, or death from renal or cardiovascular causes. Prespecified secondary outcomes were tested hierarchically. RESULTS The trial was stopped early after a planned interim analysis on the recommendation of the data and safety monitoring committee. At that time, 4401 patients had undergone randomization, with a median follow-up of 2.62 years. The relative risk of the primary outcome was 30% lower in the canagliflozin group than in the placebo group, with event rates of 43.2 and 61.2 per 1000 patient-years, respectively (hazard ratio, 0.70; 95% confidence interval [CI], 0.59 to 0.82; P=0.00001). The relative risk of the renal-specific composite of end-stage kidney disease, a doubling of the creatinine level, or death from renal causes was lower by 34% (hazard ratio, 0.66; 95% CI, 0.53 to 0.81; P<0.001), and the relative risk of end-stage kidney disease was lower by 32% (hazard ratio, 0.68; 95% CI, 0.54 to 0.86; P=0.002). The canagliflozin group also had a lower risk of cardiovascular death, myocardial infarction, or stroke (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01) and hospitalization for heart failure (hazard ratio, 0.61; 95% CI, 0.47 to 0.80; P<0.001). There were no significant differences in rates of amputation or fracture. CONCLUSIONS In patients with type 2 diabetes and kidney disease, the risk of kidney failure and cardiovascular events was lower in the canagliflozin group than in the placebo group at a median follow-up of 2.62 years

Measurement of the production cross section for Z + b jets in proton-proton collisions at s\sqrt{s} = 13 TeV

The measurement of the cross section for the production of a Z boson, decaying to dielectrons or dimuons, in association with at least one bottom quark jet is performed with proton-proton collision data at √s=13  TeV. The data sample corresponds to an integrated luminosity of 137  fb$^{-1}$, collected by the CMS experiment at the LHC during 2016–2018. The integrated cross sections for Z+≥1 b jet and Z+≥2 b jets are reported for the electron, muon, and combined channels. The fiducial cross sections in the combined channel are 6.52±0.04(stat)±0.40(syst)±0.14(theo)  pb for Z+≥1 b jet and 0.65±0.03(stat)±0.07(syst)±0.02(theo)  pb for Z+≥2 b jets. The differential cross section distributions are measured as functions of various kinematic observables that are useful for precision tests of perturbative quantum chromodynamics predictions. The ratios of integrated and differential cross sections for Z+≥2b  jets and Z+≥1 b jet processes are also determined. The value of the integrated cross section ratio measured in the combined channel is 0.100±0.005(stat)±0.007(syst)±0.003(theo). All measurements are compared with predictions from various event generators