Τρίτη, 21 Φεβρουαρίου 2017

Delivery of radiation therapy in resource-limited settings: A pilot quality assessment study

Abstract

Progress has been made in resource-limited countries in treating acute lymphoblastic leukemia, but advances in solid malignancies have been slower. Multidisciplinary care coordination is challenging, assessing adherence to guidelines through quality improvement initiatives is essential. We characterized deviations from guidelines in the delivery of radiation in a middle-income country program as a pilot for evaluating adequacy of local control and as surrogate for integration of multidisciplinary care. One-third of patients for whom it was indicated did not receive radiation. Of the patients who received radiation, 95% had a deviation. This study underscores the importance of quality assessment in resource-limited settings.



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Accurate eQTL prioritization with an ensemble-based framework

Abstract

We present a novel ensemble-based computational framework, EnsembleExpr, that achieved the best performance in the Fourth Critical Assessment of Genome Interpretation (CAGI4) “eQTL-causal SNPs” challenge for identifying eQTLs and prioritizing their gene expression effects. Expression quantitative trait loci (eQTLs) are genome sequence variants that result in gene expression changes and thus are prime suspects in the search for contributions to the causality of complex traits. When EnsembleExpr is trained on data from massively parallel reporter assays (MPRA) it accurately predicts reporter expression levels from unseen regulatory sequences and identifies sequence variants that exhibit significant changes in reporter expression. Compared with other state-of-the-art methods, EnsembleExpr achieved competitive performance when applied on eQTL datasets determined by other protocols. We envision EnsembleExpr to be a resource to help interpret non-coding regulatory variants and prioritize disease-associated mutations for downstream validation.

This article is protected by copyright. All rights reserved



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Issue 1 for volume 23 is out

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Human Birth Weight and Reproductive Immunology: Testing for Interactions between Maternal and Offspring KIR and HLA-C Genes

Background/Aims: Maternal and offspring cell contact at the site of placentation presents a plausible setting for maternal-fetal genotype (MFG) interactions affecting fetal growth. We test hypotheses regarding killer cell immunoglobulin-like receptor (KIR) and HLA-C MFG effects on human birth weight by extending the quantitative MFG (QMFG) test. Methods: Until recently, association testing for MFG interactions had limited applications. To improve the ability to test for these interactions, we developed the extended QMFG test, a linear mixed-effect model that can use multi-locus genotype data from families. Results: We demonstrate the extended QMFG test's statistical properties. We also show that if an offspring-only model is fit when MFG effects exist, associations can be missed or misattributed. Furthermore, imprecisely modeling the effects of both KIR and HLA-C could result in a failure to replicate if these loci's allele frequencies differ among populations. To further illustrate the extended QMFG test's advantages, we apply the extended QMFG test to a UK cohort study and the Norwegian Mother and Child Cohort (MoBa) study. Conclusion: We find a significant KIR-HLA-C interaction effect on birth weight. More generally, the QMFG test can detect genetic associations that may be missed by standard genome-wide association studies for quantitative traits.
Hum Hered 2016;81:181-193

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How Can We Explain Very Low Odds Ratios in GWAS I. Polygenic Models

Genome-wide association studies of common diseases often identify a number of disease-related SNPs that reach highly significant p values but at the same time show very low disease odds ratios (ORs), most Hum Hered 2016;81:173-180

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New species of bushbaby found in disappearing forests of Angola

angolan-dwarf-galago-g.kumbirensis-in-an

The Angolan dwarf galago is the fifth new primate species found in mainland Africa since 2000, but its habitat is under threat

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Leptospirosis

Leptospirosis: An infectious disease caused by a particular type of bacteria called a spirochete transmitted by rats as well as by skunks, opossums, raccoons, foxes, and other vermin. Leptospirosis occurs worldwide but is most commonly acquired in the tropics. About 100 cases of leptospirosis are reported each year in the US. The disease is becoming a greater risk as more people travel to undeveloped areas of the world. (Athletes who participated in the Eco-Challenge-Sabah 2000 multisport expedition in Borneo, Malaysia, in August 2000 contracted leptospirosis after coming in contact with the Segama River.).

Symptoms begin from 2 to 25 days after, initial direct exposure to the urine or tissue of an infected animal. This can even occur via contaminated soil or water. Veterinarians and farm workers are at particularly high risk.

The illness typically progresses through three phases. The first phase of symptoms includes headaches, muscle aches, eye pain with bright lights, followed by chills and fever. Watering and redness of the eyes occur and symptoms seem to improve by day 5 to 9. The second phase of illness begins after a few days of feeling pretty well. The initial symptoms recur with fever and aching with stiffness of the neck. Some patients develop serious inflammation of the nerve to the eye, brain, spinal column (meningitis), or other nerves. The final third phase, from 2 to 4 weeks after the initial infection, features recurrent fever and muscle aching.

Leptospirosis with liver disease is called Weil's syndrome and is characterized by yellowing of the eyes (jaundice) from liver disease. Patients with Weil's syndrome can also develop kidney disease and have more serious involvement of the organs affected.

Treatment involves high doses of antibiotics which are most effective when initiated early in the course of the illness. Doxycycline and penicillin are examples of antibiotics commonly used.



MedTerms (TM) is the Medical Dictionary of MedicineNet.com.
We Bring Doctors' Knowledge To You

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New species of bushbaby found in disappearing forests of Angola

The Angolan dwarf galago is the fifth new primate species found in mainland Africa since 2000, but its habitat is under threat

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An exploratory study of the potential of LIBS for visualizing gunshot residue patterns

Gunshot residues (GSR), also known as cartridge discharge residues or firearms discharge residues, are particles produced during the discharge of a firearm [1]. These particles, typically of micron dimensions, are a mixture of organic compounds, coming mainly from the propellant, and inorganic compounds from the primer, propellant, cartridge case, bullet or the firearm itself. GSR particles are launched with the projectile and are transferred to the victim (target), the shooter or to different objects at the scene.

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Factors associated with latent fingerprint exclusion determinations

Historically, the latent print1 [1–9] examination process was primarily focused on identifying (or individualizing) the person (subject) who left a latent print. Only in special circumstances did examiners need to make the distinction between not identifying the source of a latent print (“non-identification”) and determining that a specific finger or palm from a subject was not the source of a latent print (exclusion). “Non-identification” is inherently ambiguous, as it does not differentiate between exclusions and inconclusive determinations: exclusions explicitly indicate that a subject was not the source of a latent, whereas inconclusives indicate that the examiner could not determine whether or not a subject was the source of a latent.

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The Development of a Stabbing Machine for Forensic Textile Damage Analysis.

Stab injuries and fatalities are common crimes of violence in several countries, particularly those where access to firearms is restricted including Australia, Scandinavia and the United Kingdom [1]. For example, in Australia, more homicide victims die from stab wounds than from any other single cause. The total number of homicides that were attributed to knives and sharp implements peaked in 2006-08 to 43%, and has remained consistent on average until 2011 [2,3]. Analysis of damage to the victim’s clothing such as cuts and tears caused by a weapon may provide important forensic information [4,5].

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Academy of Management Annals

Academy of Management Annals, published by Academy of Management, last updated on 2017-02-21, available at http://annals.aom.org

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Targeted knockdown of polo-like kinase 1 alters metabolic regulation in melanoma

A limited number of studies have indicated an association of the mitotic kinase polo-like kinase 1 (PLK1) and cellular metabolism. Here, employing an inducible RNA interference approach in A375 melanoma cells coupled with a PCR array and multiple validation approaches, we demonstrated that PLK1 alters a number of genes associated with cellular metabolism. PLK1 knockdown resulted in a significant downregulation of IDH1, PDP2 and PCK1 and upregulation of FBP1. Ingenuity Pathway Analysis (IPA) identified that 1) glycolysis and the pentose phosphate pathway are major canonical pathways associated with PLK1, and 2) PLK1 inhibition-modulated genes were largely associated with cellular proliferation, with FBP1 being the key modulator.

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Cooperation of Musashi-2, Numb, MDM2, and P53 in drug resistance and malignant biology of pancreatic cancer [Research]

Our earlier work showed that Musashi (MSI)-2 promoted the development of pancreatic cancer (PC) by down-regulating Numb, which prevented murine double-minute (MDM)-2–mediated p53 ubiquitin degradation. Thus, we investigate the relationship among MSI2, Numb, MDM2, and p53 in PC in vitro and in vivo, an association that has not been reported to our knowledge. MSI2 had no relationship with mutant p53 (mtp53) and wild-type p53 (wtp53) in normal PC cells. However, in response to gemcitabine or cisplatin treatment, MSI2 silencing simultaneously down-regulated MDM2 and up-regulated Numb and wtp53 protein levels. Moreover, these 4 endogenous proteins can be coimmunoprecipitated as a quaternary complex. Numb small interfering RNA (siRNA) reversed the MSI2 silencing–induced p53 increase. During treatment with chemical agents, MSI2 silencing decreased drug resistance and cell motility in vitro and inhibited tumor growth in vivo, all of which were significantly reversed by p53 siRNA. MSI2 was also negatively associated with Numb and positively associated with MDM2 expression in tissue. Overexpression of MSI2, MDM2, and mtp53 and weak expression of Numb were closely associated with aggressive clinicopathologic characteristics and poor prognosis for patients with PC. MSI2 negatively regulates wtp53 protein by up-regulating MDM2 and down-regulating Numb after treatment with chemical agents. MSI2 promotes drug resistance and malignant biology of PC in a p53-dependent manner.—Sheng, W., Dong, M., Chen, C., Wang, Z., Li, Y., Wang, K., Li, Y., Zhou, J. Cooperation of Musashi-2, Numb, MDM2, and P53 in drug resistance and malignant biology of pancreatic cancer.



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Functional expression of dopamine D2 receptor is regulated by tetraspanin 7-mediated postendocytic trafficking [Research]

The dopaminergic system plays an essential role in various functions of the brain, including locomotion, memory, and reward, and the deregulation of dopaminergic signaling as a result of altered functionality of dopamine D2 receptor (DRD2) is implicated in multiple neurologic and psychiatric disorders. Tetraspanin-7 (TSPAN7) is expressed to variable degrees in different tissues, with the highest level in the brain, and multiple mutations in TSPAN7 have been implicated in intellectual disability. Here, we tested the hypothesis that TSPAN7 may be a binding partner of DRD2 that is involved in the regulation of its functional activity. Our results showed that TSPAN7 was associated with DRD2 and reduced its surface expression by enhancing DRD2 internalization. Immunocytochemical analysis revealed that TSPAN7 that resides in the plasma membrane and early and late endosomes promoted internalization of DRD2 and its localization to endosomal compartments of the endocytic pathway. Furthermore, we observed that TSPAN7 deficiency increased surface localization of DRD2 concurrent with the decrease of its endocytosis, regardless of dopamine treatment. Finally, TSPAN7 negatively affects DRD2-mediated signaling. These results disclosed a previously uncharacterized role of TSPAN7 in the regulation of the expression and functional activity of DRD2 by postendocytic trafficking.—Lee, S.-A., Suh, Y., Lee, S., Jeong, J., Kim, S. Je., Kim, S. Ju., Park, S. K. Functional expression of dopamine D2 receptor is regulated by tetraspanin 7–mediated postendocytic trafficking.



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Variable DAXX gene methylation is a common feature of placental trophoblast differentiation, preeclampsia, and response to hypoxia [Research]

Placental functioning relies on the appropriate differentiation of progenitor villous cytotrophoblasts (CTBs) into extravillous cytotrophoblasts (EVCTs), including invasive EVCTs, and the multinucleated syncytiotrophoblast (ST) layer. This is accompanied by a general move away from a proliferative, immature phenotype. Genome-scale expression studies have provided valuable insight into genes that are associated with the shift to both an invasive EVCT and ST phenotype, whereas genome-scale DNA methylation analysis has shown that differentiation to ST involves widespread methylation shifts, which are counteracted by low oxygen. In the current study, we sought to identify DNA methylation variation that is associated with transition from CTB to ST in vitro and from a noninvasive to invasive EVCT phenotype after culture on Matrigel. Of the several hundred differentially methylated regions that were identified in each comparison, the majority showed a loss of methylation with differentiation. This included a large differentially methylated region (DMR) in the gene body of death domain-associated protein 6 (DAXX ), which lost methylation during both CTB syncytialization to ST and EVCT differentiation to invasive EVCT. Comparison to publicly available methylation array data identified the same DMR as among the most consistently differentially methylated genes in placental samples from preeclampsia pregnancies. Of interest, in vitro culture of CTB or ST in low oxygen increases methylation in the same region, which correlates with delayed differentiation. Analysis of combined epigenomics signatures confirmed DAXX DMR as a likely regulatory element, and direct gene expression analysis identified a positive association between methylation at this site and DAXX expression levels. The widespread dynamic nature of DAXX methylation in association with trophoblast differentiation and placenta-associated pathologies is consistent with an important role for this gene in proper placental development and function.—Novakovic, B., Evain-Brion, D., Murthi, P., Fournier, T., Saffery, R. Variable DAXX gene methylation is a common feature of placental trophoblast differentiation, preeclampsia, and response to hypoxia.



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Corneal surface glycosylation is modulated by IL-1R and Pseudomonas aeruginosa challenge but is insufficient for inhibiting bacterial binding [Research]

Cell surface glycosylation is thought to be involved in barrier function against microbes at mucosal surfaces. Previously we showed that the epithelium of healthy mouse corneas becomes vulnerable to P. aeruginosa adhesion if it lacks the innate defense protein MyD88 (myeloid differentiation primary response gene 88), or after superficial injury by blotting with tissue paper. Here we explored their effect on corneal surface glycosylation using a metabolic label, tetra-acetylated N-azidoacetylgalactosamine (Ac4GalNAz). Ac4GalNAz treatment labeled the surface of healthy mouse corneas, leaving most cells viable, and bacteria preferentially associated with GalNAz-labeled regions. Surprisingly, corneas from MyD88–/– mice displayed similar GalNAz labeling to wild-type corneas, but labeling was reduced and patchy on IL-1 receptor (IL-1R)-knockout mouse corneas (P < 0.05, ANOVA). Tissue paper blotting removed GalNAz-labeled surface cells, causing DAPI labeling (permeabilization) of underlying cells. MS of material collected on the tissue paper blots revealed 67 GalNAz-labeled proteins, including intracellular proteins. These data show that the normal distribution of surface glycosylation requires IL-1R, but not MyD88, and is not sufficient to prevent bacterial binding. They also suggest increased P. aeruginosa adhesion to MyD88–/– and blotted corneas is not due to reduction in total surface glycosylation, and for tissue paper blotting is likely due to cell permeabilization.—Jolly, A. L., Agarwal, P., Metruccio, M. M. E., Spiciarich, D. R., Evans, D. J., Bertozzi, C. R., Fleiszig, S. M. J. Corneal surface glycosylation is modulated by IL-1R and Pseudomonas aeruginosa challenge but is insufficient for inhibiting bacterial binding.



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Association of Airway Abnormalities with 22q11.2 Deletion Syndrome

22q11.2 deletion syndrome (22q11.2DS) presents with complex but variable symptoms, including cardiac, immune, palatal, endocrine, cognitive, and psychiatric issues. However, an association of 22q11.2DS with structural airway abnormalities has not been formally described. The aim of this study was to document the frequency of this association.

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Reliability and validity of the Dutch pediatric voice handicap index

The pediatric voice handicap index (pVHI) has been developed to provide a better insight into the parents’ perception of their child's voice related quality of life. The purpose of the present study was to validate the Dutch pVHI by evaluating its internal consistency and reliability. Furthermore, we determined the optimal cut-off point for a normal pVHI score.

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Genomic and epigenomic heterogeneity of hepatocellular carcinoma

Understanding the intratumoral heterogeneity of hepatocellular carcinoma (HCC) is instructive for developing personalized therapy and identifying molecular biomarkers. Here we applied whole-exome sequencing to 69 samples from 11 patients to resolve the genetic architecture of subclonal diversification. Spatial genomic diversity was found in all 11 HCC cases, with 29% of driver mutations being heterogeneous, including TERT, ARID1A, NOTCH2, and STAG2. Similar with other cancer types, TP53 mutations were always shared between all tumor regions i.e. located on the "trunk" of the evolutionary tree. In addition, we found that variants within several drug targets such as KIT, SYK and PIK3CA were mutated in a fully clonal manner, indicating their therapeutic potentials for HCC. Temporal dissection of mutational signatures suggested that mutagenic processes associated with exposure to aristolochic acid and aflatoxin might play a more important role in early, as opposed to late, stages of HCC development. Moreover, we observed extensive intratumoral epigenetic heterogeneity in HCC based on multiple independent analytical methods and showed that intratumoral methylation heterogeneity might play important roles in the biology of HCC cells. Our results also demonstrated prominent heterogeneity of intratumoral methylation even in a stable HCC genome. Together, these findings highlight widespread intratumoral heterogeneity at both the genomic and epigenomic levels in HCC and provide an important molecular foundation for better understanding the pathogenesis of this malignancy.

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HuR small molecule inhibitor elicits differential effects in adenomatosis polyposis and colorectal carcinogenesis

HuR is an RNA-binding protein implicated in immune homeostasis and various cancers, including colorectal cancer (CRC). HuR binding to AU-rich elements within the 3' untranslated region of mRNAs encoding oncogenes, growth factors and various cytokines leads message stability and translation. In this study, we evaluated HuR as a small molecule target for preventing CRC in high risk groups such as those with familial adenomatosis polyposis (FAP) or inflammatory bowel disease (IBD). In human specimens, levels of cytoplasmic HuR were increased in colonic epithelial cells from patients with IBD, IBD-cancer, FAP-adenoma and CRC, but not in patients with IBD-dysplasia. Intraperitoneal injection of the HuR small-molecule inhibitor MS-444 in AOM/DSS mice, a model of IBD and inflammatory colon cancer, augmented DSS-induced weight loss and increased tumor multiplicity, size, and invasiveness. MS-444 treatment also abrogated tumor cell apoptosis and depleted tumor-associated eosinophils, accompanied by a decrease in IL-18 and eotaxin-1. In contrast, HuR inhibition in APCMin mice, a model of FAP and colon cancer, diminished the number of small intestinal tumors generated. In this setting, fecal microbiota evaluated by 16S rRNA gene amplicon sequencing shifted to a state of reduced bacterial diversity, with an increased representation of Prevotella, Akkermansia and Lachnospiraceae. Taken together, our results indicate that HuR activation is an early event in FAP-adenoma but is not present in IBD-dysplasia. Further, our results offer a preclinical proof of concept for HuR inhibition as an effective means of FAP chemoprevention, with caution advised in the setting of IBD.

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Interaction of plasmenylcholine with free radicals in selected model systems

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Publication date: Available online 21 February 2017
Source:Free Radical Biology and Medicine
Author(s): A. Broniec, A. Żądło, A. Pawlak, B. Fuchs, R. Kłosiński, D. Thompson, T. Sarna
Plasmalogens (Plg) - naturally occurring glycerophospholipids with the vinyl-ether group in the sn-1 position are generally viewed as physiological antioxidants. Although there are numerous examples of antioxidant action of plasmalogen in cell cultures and in experimental animals, this hypothesis is far from being satisfactorily proven due to substantial limitations of such studies. Thus, plasmalogen reactivity in cells results in the accumulation of toxic byproducts and the experimental design is usually too complicated to evaluate the protective function of solely one type of lipid molecular species. In this study, experiments were performed in homogenous and heterogeneous model systems consisting of solutions in organic solvents as well as micelles and liposomes containing pure synthetic plasmenylcholines. Under the experimental conditions used, chemical reactivity of plasmalogens could be attributed to specific fatty acid esterification pattern. This is important because the chemical reactivity cannot be separated from physico-chemical properties of the lipids. Time-dependent formation of phospholipid and cholesterol hydroperoxides were determined by iodometric assay and HPLC-EC. EPR oximetry and Clark electrode were employed to detect the accompanying changes in oxygen concentration. Oxidation of the studied lipids was monitored by standard colorimetric TBARS method as well as MALDI-TOF mass spectrometry. Our data indicate that the reactivity of sn-2 monounsaturated vinyl ether lipids in peroxyl radical-induced or iron-catalyzed peroxidation reactions is comparable with that of their diacyl analogs. In samples containing cholesterol and plasmalogens, oxidative processes lead to accumulation of the radical oxidation product of cholesterol. It can be concluded that the antioxidant action of plasmalogens takes place intramolecularly rather than intermolecularly and depends on the degree of unsaturation of esterified fatty acids. Thus, it is questionable if plasmalogens can really be viewed as “endogenous antioxidant”, even though they may exhibit, under special conditions, protective effect.



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Dipeptide HCH6-1 inhibits neutrophil activation and protects against acute lung injury by blocking FPR1

Publication date: Available online 21 February 2017
Source:Free Radical Biology and Medicine
Author(s): Shun-Chin Yang, Shih-Hsin Chang, Pei-Wen Hsieh, Yin-Ting Huang, Chiu-Ming Ho, Yung-Fong Tsai, Tsong-Long Hwang
Formyl peptide receptor 1 (FPR1) is an emerging therapeutic target for the discovery of drugs to treat neutrophilic inflammatory diseases. However, development of FPR1 antagonists for clinical use is still inadequate. The purpose of this study was to identify a synthetic dipeptide N-(N-benzoyl-L-tryptophanyl)-D-phenylanlanine methyl ester (HCH6-1) as a FPR1 inhibitor and to investigate its protective effects against acute lung injury (ALI). HCH6-1 inhibited superoxide anion generation, elastase release, and chemotaxis in human neutrophils specifically activated by formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLF), an FPR1 agonist. HCH6-1 produced right shifts in the concentration-response curves of fMLF, suggesting that HCH6-1 was a competitive antagonist of FPR1. Indeed, HCH6-1 bound to FPR1 in human neutrophils and neutrophil-like THP-1 as well as hFPR1-transfected HEK293 cells. Also, the FPR1 downstream signaling pathways were competitively inhibited by HCH6-1. Furthermore, HCH6-1 prevented pulmonary neutrophil infiltration and edema along with alveolar damage in LPS-induced ALI in mice. Our findings suggest that HCH6-1, a FPR1 antagonist, may have potential as a new therapeutic agent for treating FPR1-involved inflammatory lung diseases.

Graphical abstract

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Homozygous mutation in TXNRD1 is associated with genetic generalized epilepsy

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Publication date: Available online 21 February 2017
Source:Free Radical Biology and Medicine
Author(s): Alexei P Kudin, Gregor Baron, Gábor Zsurka, Kevin G Hampel, Christian E Elger, Alexander Grote, Yvonne Weber, Holger Lerche, Holger Thiele, Peter Nürnberg, Herbert Schulz, Ann-Kathrin Ruppert, Thomas Sander, Qing Cheng, Elias SJ Arnér, Lutz Schomburg, Sandra Seeher, Noelia Fradejas-Villar, Ulrich Schweizer, Wolfram S Kunz
Increased oxidative stress has been widely implicated in the pathogenesis in various forms of human epilepsy. Here, we report a homozygous mutation in TXNRD1 (thioredoxin reductase 1) in a family with genetic generalized epilepsy. TXNRD1 is an essential selenium-containing enzyme involved in detoxification of reactive oxygen species (ROS) and redox signaling. The TXNRD1 mutation p.Pro190Leu affecting a highly conserved amino acid residue was identified by whole-exome sequencing of blood DNA from the index patient. The detected mutation and its segregation within the family – all siblings of the index patient were homozygous and the parents heterozygous – were confirmed by Sanger sequencing. TXNRD1 activity was determined in subcellular fractions from a skeletal muscle biopsy and skin fibroblasts of the index patient and the expression levels of the mutated protein were assessed by 75Se labeling and Western blot analysis. As result of the mutation, the activity of TXNRD1 was reduced in the patient's fibroblasts and skeletal muscle (to 34 ± 3% and 16 ± 8% of controls, respectively). In fibroblasts, we detected reduced 75Se-labeling of the enzyme (41 ± 3% of controls). An in-depth in vitro kinetic analysis of the recombinant mutated TXNRD1 indicated 30–40% lowered kcat/Se values. Therefore, a reduced activity of the enzyme in the patient's tissue samples is explained by (i) lower enzyme turnover and (ii) reduced abundance of the mutated enzyme as confirmed by Western blotting and 75Se labeling. The mutant fibroblasts were also found to be less resistant to a hydrogen peroxide challenge. Our data agree with a potential role of insufficient ROS detoxification for disease manifestation in genetic generalized epilepsy.



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The effect of oxidized phospholipids on phenotypic polarization and function of macrophages

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Publication date: Available online 21 February 2017
Source:Free Radical Biology and Medicine
Author(s): Vlad Serbulea, Dory DeWeese, Norbert Leitinger
Oxidized phospholipids are products of lipid oxidation that are found on oxidized low-density lipoproteins and apoptotic cell membranes. These biologically active lipids were shown to affect a variety of cell types and attributed pro-as well as anti-inflammatory effects. In particular, macrophages exposed to oxidized phospholipids drastically change their gene expression pattern and function. These ‘Mox,’macrophages were identified in atherosclerotic lesions, however, it remains unclear how lipid oxidation products are sensed by macrophages and how they influence their biological function. Here, we review recent developments in the field that provide insight into the structure, recognition, and downstream signaling of oxidized phospholipids in macrophages.



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Regulation of STAT3 and NF-κB Activations by S-Nitrosylation in Multiple Myeloma

Publication date: Available online 21 February 2017
Source:Free Radical Biology and Medicine
Author(s): Jinsu Kim, Seungho Choi, Nishant Saxena, Avtar K. Singh, Inderjit Singh, Je-Seong Won
Numerous reports suggest that aberrant activations of STAT3 and NF-κB promote survival and proliferation of multiple myeloma (MM) cells. In the present report, we demonstrate that a synthetic S-nitrosothiol compound, S-nitroso-N-acetylcysteine (SNAC), inhibits proliferation and survival of multiple MM cells via S-nitrosylation-dependent inhibition of STAT3 and NF-κB. In human MM cells (e.g. U266, H929, and IM-9 cells), SNAC treatment increased S-nitrosylation of STAT3 and NF-κB and inhibited their activities. Consequently, SNAC treatment resulted in MM cell cycle arrest at G1/S check point and inhibited their proliferation. SNAC also decreased the expression of cell survival factors and increased the activities of caspases, thus increased sensitivity of MM cells to melphalan, a chemotherapeutic agent for MM. In U266 xenografted mice, SNAC treatment decreased the activity of STAT3 and reduced the growth of human CD138 positive cells (U266 cells) in the bone marrow and also reduced their production of human IgE into the serum. Taken together, these data document the S-nitrosylation mediated inhibition of MM cell proliferation and cell survival via inhibition of STAT3 and NF-κB pathways and its efficacy in animal model of MM.

Graphical abstract

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Unraveling the Structural Basis of Grazoprevir Potency Against Clinically Relevant Substitutions in Hepatitis C Virus NS3/4A Protease from Genotype 1a [Microbiology]

Grazoprevir is a potent pan-genotype, macrocyclic inhibitor of hepatitis C virus (HCV) NS3/4A protease and was developed for treating chronic HCV infection. In HCV genotype (GT) 1a, grazoprevir maintains potent activity against a majority of NS3 resistance-associated amino acid substitutions including the highly prevalent and naturally-occurring Q80K polymorphism that impacts simeprevir, another NS3/4A protease inhibitor. The basis for an unexpected difference in the clinical impact of some NS3 substitutions was investigated. Phenotypic analysis of resistance-associated substitutions identified in NS3 from GT1a-infected patients who failed therapy with grazoprevir (in combination with elbasvir, an inhibitor of HCV NS5A protein) showed that positions 56, 156, and 168 in NS3 were most impactful because they diminished protein-inhibitor interactions. While an amino acid substitution from aspartic acid (D) to alanine (A) at position 168 (D168A) reduced the potency of grazoprevir, its combination with R155K unexpectedly nullified this effect. Molecular dynamics and free-energy surface studies indicated that D168 is important in anchoring R155 for ligand binding, but is not critical for K155 because of the inherent flexibility of its side-chain. Moreover, modeling studies supported a strong direct cation-heterocycle interaction between the K155 side-chain of the double substitution, R155K_D168A, and the lone pair on the pyridine in grazoprevir. This unique interaction provides a structural basis for grazoprevir's higher potency than simeprevir, an NS3/4A protease inhibitor, to which the double substitution confers a significant reduction in potency. Our findings are consistent with the detection of R155K_D168A in NS3 from virologic failures treated with simeprevir but not grazoprevir.

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Molecular Insights into Hydrogen Peroxide Sensing Mechanism of the Metalloregulator MntR in Controlling Bacterial Resistance to Oxidative Stresses [Gene Regulation]

Manganese contributes to anti-oxidative stress particularly in catalase-devoid bacteria, and DtxR family metalloregulators, through sensing cellular Mn2+ content, regulate its homeostasis. Here, we show that metalloregulator MntR (So-MntR) functions dually as Mn2+ and H2O2 sensors in mediating H2O2 resistance by an oral streptococcus. H2O2 disrupted So-MntR's binding to Mn2+ transporter mntABC promoter, and induced disulfide-linked dimerization of the protein. Mass spectrometry identified Cys11-Cys156 and Cys11-Cys11 disulfide-linked peptides in H2O2 treated So-MntR. Site mutagenesis of Cys11 and Cys156, and particularly Cys11, abolished H2O2-induced disulfide-linked dimers, and weaken H2O2 damage on So-MntR binding, indicating that H2O2 inactivates So-MntR via disulfide-linked dimerization. So-MntR C123S mutant was extremely sensitive to H2O2 oxidization in dimerization/oligomerization, probably because the mutagenesis caused a conformational change that facilitates Cys11-Cys156 disulfide-linkage. Intermolecular Cys11-Cys11 disulfide was detected in C123S/C156S double mutant. Redox Western blot detected So-MntR oligomers in air-exposed cells, but remarkably decreased upon H2O2 pulsing, suggesting a proteolysis of the disulfide-linked So-MntR oligomers. Remarkably, elevated C11S and C156S but much lower C123S proteins were detected in H2O2-pulsed cells, confirming Cys11 and Cys156 contributed to H2O2-induced oligomerization and degradation. Accordingly, in the C11S and C156S mutants, expression of mntABC and cellular Mn2+ were decreased but H2O2 susceptibility increased. While in the C123S mutant, increased mntABC expression, cellular Mn2+ content and Mn-mediated H2O2 survival were determined. Given the wide distribution of Cys11 in streptococcal DtxR-like metalloregulators, the disclosed redox regulatory function and mechanism of So-MntR can be employed by the DtxR family proteins in bacterial resistance to oxidative stress.

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Lipid Sensing by mTOR via de novo Synthesis of Phosphatidic Acid [Lipids]

mTOR, the mammalian target of rapamycin, integrates growth factor and nutrient signals to promote a transformation from catabolic to anabolic metabolism, cell growth, and cell cycle progression. Phosphatidic acid (PA)2 interacts with the FRB (FK506 binding protein-12-rapamycin binding) domain of mTOR, which stabilizes both mTOR complexes - mTORC1 and mTORC2. We report here that mTORC1 and mTORC2 are activated in response to exogenously supplied fatty acids via the de novo synthesis of PA, a central metabolite for membrane phospholipid biosynthesis. We examined the impact of exogenously supplied fatty acids on mTOR in KRas-driven cancer cells, which are programmed to utilize exogenous lipids. The induction of mTOR by oleic acid was dependent upon the enzymes responsible for de novo synthesis of PA. Suppression of the de novo synthesis of PA resulted in G1 cell cycle arrest. While it has long been appreciated that mTOR is a sensor of amino acids and glucose, this study reveals that mTOR also senses the presence of lipids via production of PA.

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Glial Fibrillary Acidic Protein Exhibits Altered Turnover Kinetics in a Mouse Model of Alexander Disease [Protein Synthesis and Degradation]

Mutations in the astrocyte-specific intermediate filament, glial fibrillary acidic protein (GFAP), lead to the rare and fatal disorder, Alexander disease (AxD). A prominent feature of the disease is aberrant accumulation of GFAP. It has been proposed that this accumulation occurs due to an increase in gene transcription coupled with impaired proteasomal degradation, yet this hypothesis remains untested. We therefore sought to directly investigate GFAP turnover in a mouse model of AxD that is heterozygous for a disease-causing point mutation (GfapR236H/+) (and thus expresses both wild-type and mutant protein). Stable isotope labeling by amino acids in cell culture (SILAC), using primary cortical astrocytes, indicated that the in vitro half-lives of total GFAP in astrocytes from wild-type and mutant mice were similar, at ~3-4 days. Surprisingly, results obtained with stable isotope labeling of mammals (SILAM) revealed that, in vivo, the half-life of GFAP in mutant mice (15.4 &+- 0.5 days) was much shorter than that in wild-type mice (27.5 &+- 1.6 days). These unexpected in vivo data are most consistent with a model in which synthesis and degradation are both increased. Our work reveals that an AxD-causing mutation alters GFAP turnover kinetics in vivo, and provides an essential foundation for future studies aimed at preventing or reducing the accumulation of GFAP. In particular, these data suggest that elimination of GFAP might be possible, and occur more quickly than previously surmised.

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IL-1{beta} induced and p38MAPK-dependent activation of the mitogen-activated protein kinase (MAPK)-activated protein kinase (MK) 2 in hepatocytes: signal transduction with robust and concentration-independent signal amplification [Computational Biology]

The Interleukin (IL)-1β induced activation of the p38MAPK/MK2 pathway in hepatocytes is important for the control of acute phase response and regulation of liver regeneration. Many aspects of regulatory relevance of this pathway have been investigated in immune cells in the context of inflammation. However, very little is known about concentration-dependent activation kinetics and signal propagation in hepatocytes and the role of MK2. We established a mathematical model for IL-1β induced activation of the p38MAPK/MK2 pathway in hepatocytes that was calibrated to quantitative data on time- and IL-1β concentration-dependent phosphorylation of p38MAPK and MK2 in primary mouse hepatocytes. This analysis showed that in hepatocytes signal transduction from IL-1β via p38MAPK to MK2 is characterized by strong signal amplification. Quantification of p38MAPK and MK2 revealed that in hepatocytes at maximum 11.3 % of p38MAPK molecules and 36.5 % of MK2 molecules are activated in response to IL-1β. The mathematical model was experimentally validated employing phosphatase inhibitors and the p38MAPK inhibitor SB203580. Model simulations predicted an IC50 of 1 μM - 1.2 μM for SB203580 in hepatocytes. In silico analyses and experimental validation demonstrated that kinase activity of p38MAPK determines signal amplitude while phosphatase activity affects both signal amplitude and duration. p38MAPK and MK2 concentrations and responsiveness towards IL-1β was quantitatively compared between hepatocytes and macrophages. In macrophages the absolute p38MAPK and MK2 concentration was significantly higher. Finally, in line with experimental observations the mathematical model predicted a significantly higher EC50 for IL-1β induced pathway activation in macrophages compared to hepatoyces underscoring the importance of cell-type specific differences in pathway regulation.

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Sap1 is a replication initiation factor essential for the assembly of pre-replicative complex in the fission yeast Schizosaccharomyces pombe [Metabolism]

A central step in the initiation of chromosomal DNA replication in eukaryotes is the assembly of pre-replicative complex (pre-RC) at late M and early G1 phase of the cell cycles. Since 1973, four proteins or protein complexes, including cell division control protein 6 (Cdc6)/Cdc18, minichromosome maintenance protein complex (MCM), origin recognition complex (ORC), and Cdt1, are known components of the pre-RC. Previously, we reported that a non-ORC protein binds to the essential element delta 9 of the Schizosaccharomyces pombe DNA replication origin ARS3001. In this study, we identified that the non-ORC protein is Sap1. Like ORC, Sap1 binds to DNA origins during cell growth cycles. But unlike ORC, which binds to asymmetric AT-rich sequences through its nine AT-hook motifs, Sap1 preferentially binds to a DNA sequence of 5-(A/T)nC/G(A/T)9-10G/C(A/T)n-3. We also found that Sap1 and ORC physically interact. We further demonstrated that Sap1 is required for the assembly of the pre-RC because of its essential role in recruiting Cdc18 to DNA origins. Thus, we conclude that Sap1 is a replication-initiation factor that directly participates in the assembly of the pre-RC. DNA replication origins in fission yeast are defined by possessing two essential elements with one bound by ORC and the other by Sap1.

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Structural and Biochemical Analysis of Escherichia coli ObgE, a Central Regulator of Bacterial Persistence [Enzymology]

The Obg protein family belongs to the TRAFAC (translation factor) class of P-loop GTPases and is conserved from bacteria to eukaryotes. Essential roles in many different cellular processes have been suggested for the Obg protein from Escherichia coli (ObgE), and we recently showed that it is a central regulator of bacterial persistence. Here, we report the first crystal structure of ObgE at 1.85 Å resolution in the GDP-bound state, showing the characteristic N-terminal domain and a central G domain that are common to all Obg proteins. ObgE also contains an intrinsically disordered C-terminal domain, and we show here that this domain specifically contributed to GTP binding, while it did not influence GDP binding or GTP hydrolysis. Biophysical analysis, using small angle X-ray scattering and multi-angle light scattering experiments, revealed that ObgE is a monomer in solution, regardless of the bound nucleotide. In contrast to recent suggestions, our biochemical analyses further indicate that ObgE is neither activated by K+ ions nor by homodimerization. However, the ObgE GTPase activity was stimulated upon binding to the ribosome, confirming the ribosome-dependent GTPase activity of the Obg family. Combined, our data represent an important step toward further unraveling the detailed molecular mechanism of ObgE, which might pave the way to further studies into how this GTPase regulates bacterial physiology, including persistence.

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Mechanistic insights into the allosteric regulation of bacterial ADP-glucose pyrophosphorylases [Enzymology]

ADP-glucose pyrophosphorylase (AGPase) controls bacterial glycogen and plant starch biosynthetic pathways, the most common carbon storage polysaccharides in nature. AGPase activity is allosterically regulated by a series of metabolites in the energetic flux within the cell. Very recently, we reported the first crystal structures of the paradigmatic AGPase from Escherichia coli (EcAGPase) in complex with its preferred physiological negative and positive allosteric regulators, adenosine-5′-monophosphate (AMP) and fructose-1,6-bisphosphate (FBP), respectively. However, the understanding of the molecular mechanism by which AMP and FBP allosterically modulates EcAGPase enzymatic activity still remains enigmatic. Here we found that single point mutations of key residues in the AMP binding site decrease its inhibitory effect, but also clearly abolish the overall AMP-mediated stabilization effect in wild-type EcAGPase. Single point mutations of key residues for FBP binding did not revert the AMP-mediated stabilization. Strikingly, an EcAGPase·Arg130Ala mutant displayed a dramatic increase in the activity when compared with wild-type EcAGPase, and this increase correlated with a significant increment of glycogen content in vivo. The crystal structure of EcAGPase·Arg130Ala revealed unprecedented conformational changes in structural elements involved in the allosteric signal transmission. Altogether, we propose a model in which the positive and negative energy reporters regulate AGPase catalytic activity via intra- and inter-protomer crosstalk, with a ′sensory motif′ and two loops RL1 and RL2 flanking the ATP binding site playing a significant role. The information reported herein provides exciting possibilities for industrial/biotechnological applications.

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Peptide recognition by HP1 chromoshadow domains revisited: plasticity in the pseudosymmetric histone binding site of human HP1 [Protein Structure and Folding]

Heterochromatin protein 1 (HP1), a highly conserved non-histone chromosomal protein in eukaryotes, plays important roles in the regulation of gene transcription. Each of the three human homologs of HP1 includes a chromoshadow domain (CSD). The CSD interacts with various proteins bearing the PxVxL motif, but also with a region of histone H3 that bears the similar PxxVxL motif. The latter interaction has not yet been resolved in atomic detail. Here we demonstrate that the CSDs of all three human HP1 homologs have comparable affinities to the PxxVxL motif of histone H3. The HP1 C-terminal extension (CTE) enhances the affinity, as does the increasing length of the H3 peptide. The crystal structure of the human HP1γ CSD (CSDγ) in complex with an H3 peptide suggests that recognition of H3 by CSDγ to some extent resembles CSD-PxVxL interaction. Nevertheless, the prolyl residue (P) of the PxxVxL motif appears to play a distinct role from that of P in the known HP1β CSD-PxVxL complexes. We consequently generalize the historical CSD-PxVxL interaction model and expand the search scope for additional CSD binding partners.

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Covalently Linked HslU Hexamers Support a Probabilistic Mechanism that Links ATP Hydrolysis to Protein Unfolding and Translocation [Enzymology]

The HslUV proteolytic machine consists of HslV, a double-ring self-compartmentalized peptidase, and one or two AAA+ HslU ring hexamers that hydrolyze ATP to power the unfolding of protein substrates and their translocation into the proteolytic chamber of HslV. Here, we use genetic-tethering and disulfide-bonding strategies to construct HslU pseudohexamers containing mixtures of ATPase active and inactive subunits at defined positions in the hexameric ring. Genetic tethering impairs HslV binding and degradation, even for pseudohexamers with six active subunits, but disulfide-linked pseudohexamers do not have these defects, indicating that the peptide tether interferes with HslV interactions. Importantly, pseudohexamers containing different patterns of hydrolytically active and inactive subunits retain the ability to unfold protein substrates and/or collaborate with HslV in their degradation, supporting a model in which ATP hydrolysis and linked mechanical function in the HslU ring operate by a probabilistic mechanism.

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A Novel Subtilase Inhibitor in Plants Shows Structural and Functional Similarities to Protease Propeptides [Enzymology]

The propeptides of subtilisin-like serine proteinases (SBTs) serve dual functions as intramolecular chaperones that are required for enzyme folding and as inhibitors of the mature proteases. SBT propeptides are homologous to the I9 family of protease inhibitors that have only been described in fungi. Here we report the identification and characterization of Subtilisin Propeptide-Like Inhibitor 1 (SPI-1) from Arabidopsis thaliana. Sequence similarity and the shared β-α-β-β-α-β core structure identified SPI-1 as a member of the I9 inhibitor family, and as the first independent I9 inhibitor in higher eukaryotes. SPI-1 was characterized as a high-affinity, tight-binding inhibitor of Arabidopsis subtilase SBT4.13 with Kd and Ki values in the picomolar range. SPI-1 acted as a stable inhibitor of SBT4.13 over the physiologically relevant range of pH, and its inhibitory profile included many other SBTs from plants but not bovine chymotrypsin or bacterial subtilisin A. Upon binding to SBT4.13, the C-terminal extension of SPI-1 was proteolytically cleaved. The last four amino acids at the newly formed C-terminus of SPI-1 matched both, the cleavage specificity of SBT4.13 and the consensus sequence of Arabidopsis SBTs at the junction of the propeptide with the catalytic domain. The data suggest that the C-terminus of SPI-1 acts as a competitive inhibitor of target proteases as it remains bound to the active in a product-like manner. SPI-1 thus resembles SBT propetides with respect to its mode of protease inhibition. However, in contrast to SBT propeptides, SPI-1 could not substitute as a folding assistant for SBT4.13.

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Auto-inhibition of Dishevelled regulated by its extreme C-terminus plays a distinct role in Wnt/beta-catenin and Wnt/PCP signaling pathways [Developmental Biology]

Dishevelled (Dvl) is a key intracellular signaling molecule that mediates the activation of divergent Wnt pathways. It contains three highly conserved domains known as DIX, PDZ and DEP, whose functions in beta-catenin-dependent canonical Wnt and beta-catenin-independent non-canonical Wnt signaling have been well characterized. The C-terminal region is also highly conserved from invertebrates to vertebrates. However, its function in regulating the activation of different Wnt signals remains unclear. We previously reported that Dvl conformational change triggered by the highly conserved PDZ-binding C-terminus is important for the pathway specificity. Here we provide further evidence demonstrating that binding of the C-terminus to PDZ domain results in Dvl auto-inhibition in the Wnt signaling pathways. Therefore, forced binding of the C-terminus to PDZ domain reduced the activity of Dvl in non-canonical Wnt signaling, while obstruction of this interaction releases Dvl auto-inhibition, impairs its functional interaction with LRP6 in canonical Wnt signaling and increases its specificity in non-canonical Wnt signaling, which is closely correlated with an enhanced Dvl membrane localization. Our findings highlight the importance of the C-terminus in keeping Dvl in an appropriate auto-inhibited state, accessible for regulations by other partners to switch pathway specificity. Particularly, the C-terminally tagged Dvl fusion proteins that have been widely used to study the function and the cellular localization of Dvl may not truly represent the wild-type Dvl because those proteins cannot be auto-inhibited.

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Cross-talk between the Glucocorticoid Receptor and MyoD Family Inhibitor Domain Containing Protein Provides a New Mechanism for Generating Tissue-Specific Responses to Glucocorticoids [Gene Regulation]

Glucocorticoids are primary stress hormones that regulate many physiological processes, and synthetic derivatives of these molecules are widely used in the clinic. The molecular factors that govern tissue specificity of glucocorticoids, however, are poorly understood. The actions of glucocorticoids are mediated by the glucocorticoid receptor (GR). To discover new proteins that interact with GR and modulate its function, we performed a yeast 2-hybrid assay. The MyoD family inhibitor domain containing (MDFIC) protein was identified as a binding partner for GR. MDFIC associated with GR in the cytoplasm of cells, and treatment with glucocorticoids resulted in the dissociation of the GR-MDFIC complex. To investigate the function of the GR-MDFIC interaction, we performed a genome-wide microarray in intact and MDFIC deficient A549 cells that were treated with glucocorticoids. A large cohort of genes was differentially regulated by GR depending on the presence or absence of MDFIC. These gene changes were strongly associated with inflammation, and glucocorticoid regulation of the inflammatory response was altered in MDFIC-deficient cells. At a molecular level, the interaction of MDFIC with GR altered the phosphorylation status of the receptor. We demonstrate in COS-1 cells that changes in receptor phosphorylation underlie the ability of MDFIC to regulate the transcriptional activity of GR. Finally, we show that GR directly represses the MDFIC gene, revealing a negative feedback loop by which glucocorticoids limit MDFIC activity. These findings identify a new binding partner for cytoplasmic GR that modulates the receptor transcriptome and contributes to the tissue-specific actions of glucocorticoids.

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The mevalonate pathway in neurons: It's not just about cholesterol

Publication date: Available online 21 February 2017
Source:Experimental Cell Research
Author(s): Miguel Moutinho, Maria João Nunes, Elsa Rodrigues
Cholesterol homeostasis greatly impacts neuronal function due to the essential role of this sterol in the brain. The mevalonate (MVA) pathway leads to the synthesis of cholesterol, but also supplies cells with many other intermediary molecules crucial for neuronal function. Compelling evidence point to a model in which neurons shutdown cholesterol synthesis, and rely on a shuttle derived from astrocytes to meet their cholesterol needs. Nevertheless, several reports suggest that neurons maintain the MVA pathway active, even with sustained cholesterol supply by astrocytes. Hence, in this review we focus not on cholesterol production, but rather on the role of the MVA pathway in the synthesis of particular intermediaries, namely isoprenoids, and on their role on neuronal function. Isoprenoids act as anchors for membrane association, after being covalently bound to proteins, such as most of the small guanosine triphosphate-binding proteins, which are critical to neuronal cell function. Based on literature, on our own results, and on the analysis of public transcriptomics databases, we raise the idea that in neurons there is a shift of the MVA pathway towards the non-sterol branch, responsible for isoprenoid synthesis, in detriment to post-squalene branch, and that this is ultimately essential for synaptic activity. Nevertheless new tools that facilitate imaging and the biochemical characterization and quantification of the prenylome in neurons and astrocytes are needed to understand the regulation of isoprenoid production and protein prenylation in the brain, and to analyze its differences on diverse physiological or pathological conditions, such as aging and neurodegenerative states.



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NOR1 promotes hepatocellular carcinoma cell proliferation and migration through modulating the Notch signaling pathway

Publication date: Available online 21 February 2017
Source:Experimental Cell Research
Author(s): Kun You, Peisheng Sun, Zhongyi Yue, Jian Li, Wancheng Xiong, Jianguo Wang
Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide. Previous studies have reported that the oxidored-nitro domain containing protein 1 (NOR1) is a novel tumor suppressor in several tumors. Recent evidence suggests that NOR1 is strongly expressed in HCC cells. However, its role and mechanism in HCC are unclear. In the current study, Western blot and qPCR detected strong NOR1 mRNA and protein expression in HepG2 and Hep3B cells. After transfection with NOR1 siRNA or pcDNA3.1-myc-his-NOR1, the proliferation and migration of HepG2 and Hep3B cells were analyzed in vitro. HepG2 or Hep3B cells overexpressing NOR1 showed an increased proliferation and migration, whereas siRNA-mediated silencing of NOR1 showed the opposite effect. Furthermore, NOR1 activated the Notch signaling pathway, indicated by increased levels of Notch1, NICD, Hes1, and Hey1 in protein. Importantly, the Notch inhibitor DAPT downregulated Notch activation and further enhanced siNOR1-induced reduction of cell proliferation and migration in HepG2 and Hep3B cells, whereas DAPT reversed the effect of NOR1 overexpression on cell proliferation and migration. In conclusion, these results indicate that NOR1 may be involved in the progression of HCC and thus may be a potential target for the treatment of liver cancer.



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MiR-26a enhances invasive capacity by suppressing GSK3β in human lung cancer cells

Publication date: Available online 21 February 2017
Source:Experimental Cell Research
Author(s): Gaoyang Lin, Boning Liu, Zhaowei Meng, Yunde Liu, Xuebing Li, Xiang Wu, Qinghua Zhou, Ke Xu
Lung cancer is the common cause of death from cancer, and most lung cancer patients die of metastasis. MicroRNAs (miRNAs) function as either oncogenes or tumor suppressors, playing crucial role not only in tumorigenesis, but also in tumor invasion and metastasis. There are several studies showed that miR-26a is involved in carcinogenesis, however, its role in tumor metastasis need to be elucidated. In this study, we showed that ectopic expression of miR-26a enhanced migration and invasion of lung cancer cells. Glycogen synthase kinase-3β (GSK3β) was identified as a direct target of miR-26a. GSK3β expression negatively correlated with miR-26a expression in lung cancer tissues. Silencing of GSK3β achieved similar effect as miR-26a over-expression; over-expression of GSK3β reversed the enhanced effect of miR-26a on lung cancer cell migration and invasion. Further study indicated that miR-26a increased β-catenin expression and nuclear translocation. C-myc and cyclin D1, the downstream genes of β-catenin, were also up-regulated by miR-26a. Furthermore, xenograft study showed that miR-26a promoted lung cancer cell growth in vivo, and suppressed GSK3β expression. Collectively, our results demonstrated that miR-26a enhanced metastatic potential of lung cancer cells via activation of β-catenin pathway by targeting GSK3β, suggesting the potential applicability of miR-26a as a target for cancer treatment.



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CD8+ effector memory T cells induce acute rejection of allogeneic heart retransplants in mice possibly through activating expression of inflammatory cytokines

Publication date: Available online 21 February 2017
Source:Experimental Cell Research
Author(s): Gang Du, Nuo Yang, Wenlin Gong, Yuan Fang, Jian He, Nuo Zhou, Xiaoling Lu, Yongxiang Zhao
BackgroundTo investigate the effects of CD8+ memory T (Tm) cells and CD8+ effector memory T (Tem) cells on the results of allogeneic heart retransplantations performed in mice.MethodsA skin transplantation model was used to generate sensitized splenic CD8+ Tem cells for infusion into BALB/c mice. One week after infusion, the BALB/c mice underwent allogeneic heart transplantation in the abdominal cavity. Cyclosporin A was administered via intraperitoneal injection starting one day prior to transplantation to arrest immunological rejection of the transplanted heart. The effects of sensitized CD8+ cells on allogeneic heart graft rejection were examined by monitoring survival of the transplanted hearts, the infiltration of effector memory CD8+ T cells into myocardium, and expressions of inflammatory cytokines in blood serum.ResultsAdoptive transfer of sensitized CD8+ Tem cells prior to transplantation induced an acute rejection response which decreased the survival of transplanted hearts. The rejection response was accompanied by an infiltration of CD8+ Tem cells into the transplanted myocardial tissue. Additionally, infusion of sensitized CD8+ Tem cells induced markedly increased expressions of IL-2 and IFN-γ, and decreased expression of TGF-β in the transplanted hearts, as well as higher levels of IFN-γ and CXCL-9 in blood serum.ConclusionsThe infusion of sensitized CD8+ Tem cells induced an acute graft rejection response and decreased the survival of grafted hearts by regulating the expressions of inflammatory cytokines including CXCL-9, IL-2, and INF-γ. Cyclosporin A had no therapeutic effect on the graft rejection response induced by sensitized CD8+ Tem cells.



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Innate immune receptors in skeletal muscle metabolism

Publication date: Available online 21 February 2017
Source:Experimental Cell Research
Author(s): Nicolas J. Pillon, Anna Krook
Recent decades have seen increasing evidence for a role for both innate and adaptive immunity in response to changes in and in the modulation of metabolic status. This new field of immunometabolism builds on evidence for activation of immune-derived signals in metabolically relevant tissues such as adipose tissue, liver, hypothalamus and skeletal muscle. Skeletal muscle is the primary site of dietary glucose disposal and therefore a key player in the development of diabetes, but studies on the role of inflammation in modulating skeletal muscle metabolism and its possible impact on whole body insulin sensitivity are scarce. This review describes the baseline mRNA expression of innate immune receptors (Toll- and NOD-like receptors) in human skeletal muscle and summarizes studies on putative role of these receptors in skeletal muscle in the context of diabetes, obesity and whole body metabolism.



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Thiazolidinediones abrogate cervical cancer growth

Publication date: Available online 20 February 2017
Source:Experimental Cell Research
Author(s): Beverly R. Wuertz, Lindsay Darrah, Justin Wudel, Frank G. Ondrey
Peroxisome proliferator-activated receptor gamma (PPAR γ) is activated by thiazolidinedione drugs (TZDs) and can promote anti-cancer properties. We used three TZDs (pioglitazone, rosiglitazone, and ciglitazone) to target cervical cancer cell lines and a nude mouse animal model. Each agent increased activation of PPAR γ, as judged by a luciferase reporter gene assay in three HPV-associated cell lines (CaSki, SiHa, and HeLa cells) while decreasing cellular proliferation in a dose-dependent manner. They also promoted Oil Red O accumulation in treated cell lines and upregulated the lipid differentiation marker adipsin. Interestingly, xenograft HeLa tumors in nude mice treated with 100mg/kg/day pioglitazone exhibited decreased growth compared to control mice or mice treated with standard cervical chemotherapy. In conclusion, TZDs slow tumor cell growth in vitro and in vivo with decreases in cell proliferation and increases in PPAR γ and adipsin. These agents may be interesting treatments or treatment adjuncts for HPV-associated cancers or perhaps even precancerous conditions.



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Autophagy is the key process in the re-establishment of the epitheloid phenotype during mesenchymal-epithelial transition (MET)

Publication date: Available online 20 February 2017
Source:Experimental Cell Research
Author(s): Viktória Zsiros, Sándor Katz, Nikolett Dóczi, Anna L. Kiss
In previous studies we showed that during Freund's adjuvant induced inflammation rat mesenteric mesothelial cells undergo epithelial-mesenchymal transition type II (EMT). This process was characterized by a dramatic increase of the number of cell organelles and volume of mesothelial cells. After the inflammation reached its maximum, the mesenchymal-like cells gradually regained their epithelial phenotype (mesenchymal-epithelial transition, MET). During the recovery process, the decrease of the number of cell organelles was accompanied by an increasing number of autophagic structures in the cytoplasm, indicating that autophagy might play crucial role in MET. Morphometric data of this study showed that the number of the autophagic organelles increased by the time of inflammation and was the highest at day 7–8, when regeneration started. These morphological observations were supported by immunocytochemistry and Western blot analyses with various markers, directly or indirectly involved in this process. Endocytic markers were expressed at high level during both EMT and MET, while the expression of factors regulating autophagy simultaneously changed with the morphology: p-Akt and p-mTOR level was high at day 3–5 and significantly decreased when autophagy speeded up. The Beclin-1, which is the key factor of initiating autophagy, was expressed at the early time of inflammation. These results strongly suggest that autophagy plays important role in regeneration (MET), and it is regulated and synchronized by various signalling events during inflammation.



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Biochemical Changes of Salivary Gland Adenoid Cystic Carcinoma Cells Induced by SGI-1776

Publication date: Available online 20 February 2017
Source:Experimental Cell Research
Author(s): Xiuxiu Hou, Yunfang Yu, Jianguo Feng, Jiafeng Wang, Chuanming Zheng, Zhiqiang Ling, Minghua Ge, Xin Zhu
Provirus integration site for Moloney murine leukemia virus 1 (Pim-1) has proved to be an oncogene and it is known that to depress Pim-1 activity may be a novel oncological treatment strategy. SGI-1776, a small molecule, is the first clinically tested inhibitor of the Pim kinase family. Here, we aimed to explore the effect of SGI-1776 on salivary adenoid cystic carcinoma (SACC). Expression of Pim-1 was confirmed in SACC and control tissues by qRT-PCR. After SGI-1776 treatment, the Pim-1 expressions and Pim-1 kinase activity in both SACC-83 and SACC-LM cell lines were measured. Cell proliferation, cell invasion, cell cycle, apoptosis and mitochondrial membrane potential were analyzed. Also, the expression of FOXO3a, p-FOXO3a, RUNX3, Bcl-2, BAD, p-BAD, Bim and p-Bim were detected by Western blot. The results showed that Pim-1 was significantly overexpressed in SACC tissues. SGI-1776 down-regulated the Pim-1 expression, inhibited Pim-1 kinase activity, reduced cell proliferation, decreased invasive ability, increased caspase-3 activity and induced apoptosis, cell cycle arrest and mitochondrial depolarization. Reduced expression was also seen in p-FOXO3a, RUNX3, Bcl-2, p-BAD and p-Bim, whereas no significant changes were observed from FOXO3a, BAD and Bim. These results confirm the pivotal role of Pim-1 in SACC and suggest that targeting Pim-1 kinase signal pathway by SGI-1776 might be a promising therapeutic modality for SACC.



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Characterization of stem-like cells in a new astroblastoma cell line

Publication date: Available online 20 February 2017
Source:Experimental Cell Research
Author(s): Esra Aydemir Çoban, Ezgi Kasikci, Omer Faruk Karatas, Oznur Suakar, Aysegul Kuskucu, Mine Altunbek, Uğur Türe, Fikrettin Sahin, Omer Faruk Bayrak
Cell lines established from tumors are the most commonly used models in cancer research, and their use in recent years has enabled a greater understanding of the biology of cancer and the means to develop effective treatment strategies. Astroblastomas are uncommon neuroepithelial tumors of glial origin, predominantly affecting young people, mainly teenagers and children, predominantly females. To date, only a single study has reported that astroblastomas contain a large number of neural stem-like cells, which had only a partial proliferation capacity and differentiation. Our objective was to establish an astroblastoma cell line to investigate the presence of astroblastic cells and cancer stem-like cells. The migratory and invasion abilities of the cells were quantified with invasion and migration assays and compared to a glioblastoma cell line. The presence of stem cells was detected with surface-marker analysis by using flow cytometry, and measuring the differentiation ability with a differentiation assay and the self-renewal capacity with a sphere-forming assay. These characteristics may determine whether this novel cell line is a model for astroblastomas that may have stem-cell characteristics. With this novel cell line, scientists can investigate the molecular pathways underlying astroblastomas and develop new therapeutic strategies for patients with these tumors.



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Human CLEC16A regulates autophagy through modulating mTOR activity

Publication date: Available online 20 February 2017
Source:Experimental Cell Research
Author(s): Rachel Chun Yee Tam, Michelle Wing Man Li, Yan Pan Gao, Yuen Ting Pang, Sheng Yan, Wei Ge, Chak Sing Lau, Vera Sau Fong Chan
CLEC16A is genetically linked with multiple autoimmune disorders but its functional relevance in autoimmunity remains obscure. Recent evidence has signposted the emerging role of autophagy in autoimmune disease development. Here, by ectopic expression and siRNA silencing, we show that CLEC16A has an inhibitory role in starvation-induced autophagy in human cells. Combining quantitative proteomics and immunoblotting analyses, we found that CLEC16A likely regulates autophagy by activating mTOR pathway. Overexpression of CLEC16A was found to sensitize cells towards the availability of nutrients, resulting in a heightened mTOR activity, which in turn diminished LC3 autophagic activity following nutrient deprivation. CLEC16A deficiency, on the other hand, delayed mTOR activity in response to nutrient sensing, thereby resulted in an augmented autophagic response. CLEC16A was found residing in cytosolic vesicles and the Golgi, and nutrient removal promoted a stronger clustering within the Golgi, where possibly be in a vantage position to activate mTOR upon nutrient replenishment. These findings suggest that Golgi-associated CLEC16A negatively regulates autophagy via modulation of mTOR activity, and may provide support for a functional link between CLEC16A and autoimmunity.



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Reply to Grossman: The role of natural selection for the increase of Caesarean section rates [Biological Sciences]

Recently, we presented the “cliff-edge model” (1) to explain why natural selection has not reduced the high rates of fetopelvic disproportion (FPD) in childbirth. This evolutionary model predicts that birth-relevant anatomical dimensions have changed in response to the regular use of Caesarean sections (C-sections). Grossman’s (2) interesting comment on our...

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Are human heads getting larger? [Biological Sciences]

I am responding to the intriguing PNAS article by Mitteroecker et al. (1), “Cliff-edge model of obstetric selection in humans.” My understanding is that the authors believe that Caesarean section births will allow fetuses with larger heads to survive, thus allowing our species to evolve larger heads. This is an...

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Full atomistic reaction mechanism with kinetics for CO reduction on Cu(100) from ab initio molecular dynamics free-energy calculations at 298 K [Chemistry]

A critical step toward the rational design of new catalysts that achieve selective and efficient reduction of CO2 to specific hydrocarbons and oxygenates is to determine the detailed reaction mechanism including kinetics and product selectivity as a function of pH and applied potential for known systems. To accomplish this, we...

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Hippo signaling promotes JNK-dependent cell migration [Developmental Biology]

Overwhelming studies show that dysregulation of the Hippo pathway is positively correlated with cell proliferation, growth, and tumorigenesis. Paradoxically, the detailed molecular roles of the Hippo pathway in cell invasion remain debatable. Using a Drosophila invasion model in wing epithelium, we show herein that activated Hippo signaling promotes cell invasion...

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Probing equilibrium of molecular and deprotonated water on TiO2(110) [Chemistry]

Understanding adsorbed water and its dissociation to surface hydroxyls on oxide surfaces is key to unraveling many physical and chemical processes, yet the barrier for its deprotonation has never been measured. In this study, we present direct evidence for water dissociation equilibrium on rutile-TiO2(110) by combining supersonic molecular beam, scanning...

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Correction to Supporting Information for Andreu-Fernandez et al., Bax transmembrane domain interacts with prosurvival Bcl-2 proteins in biological membranes [SI Correction]

BIOCHEMISTRY Correction to Supporting Information for “Bax transmembrane domain interacts with prosurvival Bcl-2 proteins in biological membranes,” by Vicente Andreu-Fernández, Mónica Sancho, Ainhoa Genovés, Estefanía Lucendo, Franziska Todt, Joachim Lauterwasser, Kathrin Funk, Günther Jahreis, Enrique Pérez-Payá, Ismael Mingarro, Frank Edlich, and Mar Orzáez, which appeared in issue 2, January 10,...

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Correction for Holm et al., Arginine substitution of a cysteine in transmembrane helix M8 converts Na+,K+-ATPase to an electroneutral pump similar to H+,K+-ATPase [Correction]

BIOCHEMISTRY Correction for “Arginine substitution of a cysteine in transmembrane helix M8 converts Na+,K+-ATPase to an electroneutral pump similar to H+,K+-ATPase,” by Rikke Holm, Jaanki Khandelwal, Anja P. Einholm, Jens P. Andersen, Pablo Artigas, and Bente Vilsen, which appeared in issue 2, January 10, 2017, of Proc Natl Acad Sci...

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Correction for Slovic et al., Iconic photographs and the ebb and flow of empathic response to humanitarian disasters [Correction]

PSYCHOLOGICAL AND COGNITIVE SCIENCES Correction for “Iconic photographs and the ebb and flow of empathic response to humanitarian disasters,” by Paul Slovic, Daniel Västfjäll, Arvid Erlandsson, and Robin Gregory, which appeared in issue 4, January 24, 2017, of Proc Natl Acad Sci USA (114:640–644; first published January 10, 2017; 10.1073/pnas.1613977114)....

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Climate change is projected to have severe impacts on the frequency and intensity of peak electricity demand across the United States [Sustainability Science]

It has been suggested that climate change impacts on the electric sector will account for the majority of global economic damages by the end of the current century and beyond [Rose S, et al. (2014) Understanding the Social Cost of Carbon: A Technical Assessment]. The empirical literature has shown significant...

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Impact of pre-Columbian “geoglyph” builders on Amazonian forests [Sustainability Science]

Over 450 pre-Columbian (pre-AD 1492) geometric ditched enclosures (“geoglyphs”) occupy ∼13,000 km2 of Acre state, Brazil, representing a key discovery of Amazonian archaeology. These huge earthworks were concealed for centuries under terra firme (upland interfluvial) rainforest, directly challenging the “pristine” status of this ecosystem and its perceived vulnerability to human...

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Modular assembly of thick multifunctional cardiac patches [Applied Biological Sciences]

In cardiac tissue engineering cells are seeded within porous biomaterial scaffolds to create functional cardiac patches. Here, we report on a bottom-up approach to assemble a modular tissue consisting of multiple layers with distinct structures and functions. Albumin electrospun fiber scaffolds were laser-patterned to create microgrooves for engineering aligned cardiac...

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Gene activation of SMN by selective disruption of lncRNA-mediated recruitment of PRC2 for the treatment of spinal muscular atrophy [Medical Sciences]

Spinal muscular atrophy (SMA) is a neurodegenerative disease characterized by progressive motor neuron loss and caused by mutations in SMN1 (Survival Motor Neuron 1). The disease severity inversely correlates with the copy number of SMN2, a duplicated gene that is nearly identical to SMN1. We have delineated a mechanism of...

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Multifunctional, inexpensive, and reusable nanoparticle-printed biochip for cell manipulation and diagnosis [Applied Biological Sciences]

Isolation and characterization of rare cells and molecules from a heterogeneous population is of critical importance in diagnosis of common lethal diseases such as malaria, tuberculosis, HIV, and cancer. For the developing world, point-of-care (POC) diagnostics design must account for limited funds, modest public health infrastructure, and low power availability....

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Low escape-rate genome safeguards with minimal molecular perturbation of Saccharomyces cerevisiae [Genetics]

As the use of synthetic biology both in industry and in academia grows, there is an increasing need to ensure biocontainment. There is growing interest in engineering bacterial- and yeast-based safeguard (SG) strains. First-generation SGs were based on metabolic auxotrophy; however, the risk of cross-feeding and the cost of growth-controlling...

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Estrogen receptor {alpha} wields treatment-specific enhancers between morphologically similar endometrial tumors [Applied Biological Sciences]

The DNA-binding sites of estrogen receptor α (ERα) show great plasticity under the control of hormones and endocrine therapy. Tamoxifen is a widely applied therapy in breast cancer that affects ERα interactions with coregulators and shifts the DNA-binding signature of ERα upon prolonged exposure in breast cancer. Although tamoxifen inhibits...

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Loss of GET pathway orthologs in Arabidopsis thaliana causes root hair growth defects and affects SNARE abundance [Plant Biology]

Soluble N-ethylmaleimide–sensitive factor attachment protein receptor (SNARE) proteins are key players in cellular trafficking and coordinate vital cellular processes, such as cytokinesis, pathogen defense, and ion transport regulation. With few exceptions, SNAREs are tail-anchored (TA) proteins, bearing a C-terminal hydrophobic domain that is essential for their membrane integration. Recently, the...

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Kinetics, subcellular localization, and contribution to parasite virulence of a Trypanosoma cruzi hybrid type A heme peroxidase (TcAPx-CcP) [Biochemistry]

The Trypanosoma cruzi ascorbate peroxidase is, by sequence analysis, a hybrid type A member of class I heme peroxidases [TcAPx-cytochrome c peroxidase (CcP)], suggesting both ascorbate (Asc) and cytochrome c (Cc) peroxidase activity. Here, we show that the enzyme reacts fast with H2O2 (k = 2.9 × 107 M−1⋅s−1) and...

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Functional importance of stripping in NF{kappa}B signaling revealed by a stripping-impaired I{kappa}B{alpha} mutant [Biophysics and Computational Biology]

Stress-response transcription factors such as NFκB turn on hundreds of genes and must have a mechanism for rapid cessation of transcriptional activation. We recently showed that the inhibitor of NFκB signaling, IκBα, dramatically accelerates the dissociation of NFκB from transcription sites, a process we have called “stripping.” To test the...

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Reaction dynamics analysis of a reconstituted Escherichia coli protein translation system by computational modeling [Biophysics and Computational Biology]

To elucidate the dynamic features of a biologically relevant large-scale reaction network, we constructed a computational model of minimal protein synthesis consisting of 241 components and 968 reactions that synthesize the Met-Gly-Gly (MGG) peptide based on an Escherichia coli-based reconstituted in vitro protein synthesis system. We performed a simulation using...

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Dnmt3a restrains mast cell inflammatory responses [Immunology and Inflammation]

DNA methylation and specifically the DNA methyltransferase enzyme DNMT3A are involved in the pathogenesis of a variety of hematological diseases and in regulating the function of immune cells. Although altered DNA methylation patterns and mutations in DNMT3A correlate with mast cell proliferative disorders in humans, the role of DNA methylation...

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European cancer death rates will fall faster in men than in women in 2017

Death rates from cancer in the European Union (EU) are falling faster in men than in women, according to the latest predictions for European cancer deaths in 2017, published in the leading cancer journal Annals of Oncology today. Researchers in Italy,...

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Single bowel screening cuts cancer risk for over 15 years

A one-off bowel screening test reduces the risk of developing bowel cancer by more than one third and could save thousands of lives, according to a study published in The Lancet today. The researchers, funded through a Medical Research Council (MRC) and...

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Increased life expectancy as a result of non-hormonal targeted therapies for HER2 or hormone receptor positive metastatic breast cancer: a systematic review and meta-analysis

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Publication date: Available online 20 February 2017
Source:Cancer Treatment Reviews
Author(s): Rositsa G Koleva-Kolarova, Monika P Oktora, Annelies L Robijn, Marcel JW Greuter, Anna KL Reyners, Erik Buskens, Geertruida H de Bock
This article aimed to assess the clinical effectiveness of non-hormonal targeted therapies (TTs) in terms of increase of median progression-free survival (PFS) and overall survival (OS) in receptor-positive metastatic breast cancer (MBC) patients by performing a systematic review and meta-analysis. We systematically searched relevant randomized controlled trials and extracted data about number of patients on targeted and comparator therapy, receptor status, line of treatment, median PFS and OS, p values, hazard ratios (HRs) and 95% confidence intervals (CI). Inverse variance was used to estimate pooled HRs, chi-square test for heterogeneity and Jadad scale for quality were applied. Thirty eight studies (n=17,192 patients) were eligible for inclusion. TTs added 3.3 months to the median PFS [0.7–9.6; HRs 0.74, 95% CI 0.71–0.77] of receptor-positive MBC patients and prolonged their median OS with 3.5 months [0–4.7; HRs 0.90, 95% CI 0.82–0.98]. The highest increase in median PFS of 3.6 months was found in HER2-/HR+ patients, while the highest increase in median OS of 7.2 months was observed in HER2+/mixed hormone receptor (HR) status patients. First-line TTs were most effective in increasing the median PFS in the HR+/HER2- group with 2.0 months, and in the HER2+/HR-mixed group by adding 4.7 months to the median OS. Second-line TTs were most effective for HER2-/HR+ patients by adding 2.6 months to their PFS, and for HER2+/HR-mixed patients by adding 3.1 months to their median OS. Albeit small, the gain in months of median PFS and median OS was significant. Importantly, the results reported show large variation, and thus routinely applying a personalized approach seems warranted.



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The mortality reducing effect of aspirin in colorectal cancer patients: interpreting the evidence

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Publication date: Available online 20 February 2017
Source:Cancer Treatment Reviews
Author(s): Martine A. Frouws, Myrthe P.P. van Herk-Sukel, Huub A. Maas, Cornelis J.H. Van de Velde, Johanneke E.A. Portielje, Gerrit-Jan Liefers, Esther Bastiaannet
In 1971 the first study appeared that suggested a relationship between aspirin and cancer. Currently publications on the subject of aspirin and cancer are numerous, with both a beneficial effect of aspirin on cancer incidence and a beneficial effect on cancer survival. This review focusses on the relation between the use of aspirin and improved survival in colorectal cancer patients. Various study designs have been used, with the main part being observational studies and post-hoc meta-analyses of cancer outcomes in cardiovascular prevention trials. The results of these studies are unambiguously pointing towards an effect of aspirin on colorectal cancer survival, and several randomised controlled trials are currently ongoing. Some clinicians feel that the current evidence is conclusive and that the time has come for aspirin to be prescribed as adjuvant therapy. However, until this review, not much attention has been paid to the specific types of bias associated with these studies. One of these biases is confounding by indication, because aspirin is indicated for patients as secondary prevention for cardiovascular disease. This review aims to provide perspective on these biases and provide tools for the interpretation of the current evidence. Albeit promising, the current evidence is not sufficient to already prescribe aspirin as adjuvant therapy for colorectal cancer.



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Circulating intestinal fatty acid-binding protein (I-FABP) levels in acute decompensated heart failure

Publication date: Available online 20 February 2017
Source:Clinical Biochemistry
Author(s): Takeshi Kitai, Yong-Hyun Kim, Kathryn Kiefer, Rommel Morales, Allen G. Borowski, Justin L Grodin, W.H. Wilson Tang
BackgroundVenous congestion has become increasingly recognized as a potential contributor to end-organ dysfunction in heart failure. Elevated I-FABP, which is excreted specifically from damaged intestinal epithelial cells, has been found in patients with abdominal hypertension and intestinal ischemia. We hypothesize that elevated intestinal fatty acid-binding protein (I-FABP) levels would identify patients with more advanced heart failure who have venous and intestinal congestion.MethodsBaseline serum I-FABP levels were measured in 69 acute decompensated heart failure (ADHF) patients admitted to the intensive care unit for invasive hemodynamic monitoring and tailored medical therapy. Comprehensive echocardiography examinations were performed in all study patients, and clinical outcomes (death, cardiac transplant or left ventricular assist device placement) were assessed.ResultsThe median circulating I-FABP level was 853pg/ml (interquartile range: 533 to 1448pg/ml). Age, gender, race, and baseline comorbidities were comparable between patients with low and high I-FABP levels. Although there were no significant correlations between I-FABP levels and invasively-measured hemodynamic parameters nor echocardiographic parameters, patients with higher I-FABP levels (≥853g/ml) had significantly worse clinical outcomes compared to those with lower I-FABP levels (<853pg/ml, P=0.025).ConclusionCirculating I-FABP levels had no association with invasively-measured hemodynamic parameters, but were associated with adverse clinical outcomes in patients with ADHF with systolic dysfunction.



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Corrigendum to “An increased CDT camouflaged a monoclonal light chain gammopathy: An approach for diagnosis” [Clin. Biochem. 49 (2016) 835–838]

Publication date: Available online 20 February 2017
Source:Clinical Biochemistry
Author(s): M. Barbaro, G. Passerini, M. Trbos, A. Soldarini, M. Locatelli




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Non-traumatic rhabdomyolysis: Background, laboratory features, and acute clinical management

Publication date: Available online 21 February 2017
Source:Clinical Biochemistry
Author(s): Gianfranco Cervellin, Ivan Comelli, Mario Benatti, Fabian Sanchis-Gomar, Antonella Bassi, Giuseppe Lippi
Rhabdomyolysis is a relatively rare condition, but its clinical consequences are frequently dramatic in terms of both morbidity and mortality. Although no consensus has been reached so far about the precise definition of this condition, the term rhabdomyolysis describes a rapid breakdown of striated, or skeletal, muscle. It is hence characterized by the rupture and necrosis of muscle fibers, resulting in release of cell degradation products and intracellular elements within the bloodstream and extracellular space. Notably, the percentage of patients with rhabdomyolysis who develop acute kidney injury, the most dramatic consequence, varies from 13% to over 50% according to both the cause and the clinical and organizational setting where they are diagnosed. Despite direct muscle injury (i.e., traumatic rhabdomyolysis) remains the most common cause, additional causes, frequently overlapping, include hypoxic, physical, chemical or biological factors. The conventional triad of symptoms includes muscle pain, weakness and dark urine. The laboratory diagnosis is essentially based on the measurement of biomarkers of muscle injury, being creatine kinase (CK) the biochemical “gold standard” for diagnosis, and myoglobin the “gold standard” for prognostication, especially in patients with non-traumatic rhabdomyolysis. The essential clinical management in the emergency department is based on a targeted intervention to manage the underlying cause, combined with infusion of fluids and eventually sodium bicarbonate. We will present and discuss in this article the pathophysiological and clinical features of non-traumatic rhabdomyolysis, focusing specifically on Emergency Department (ED) management.



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Galactose-α-1,3-Galactose: Atypical Food Allergen or Model IgE Hypersensitivity?

Abstract

Purpose of Review

Galactose-α-1,3-galactose (α-gal) is a carbohydrate allergen with several unique characteristics. In this article, we discuss some recent advances in our understanding of the ‘alpha-gal syndrome,’ highlight data supporting the role of ticks in pathogenesis, and speculate on immune mechanisms that lead to sensitization.

Recent Findings

First described as the target of IgE in individuals suffering immediate hypersensitivity reactions to the novel anti-EGF monoclonal antibody cetuximab, it is now clear that α-gal sensitization is associated with mammalian meat allergy as well as reactions to other mammalian products. Unlike traditional IgE-mediated food allergies, reactions to α-gal often do not manifest until several hours following an exposure, although co-factors can influence the presentation. Multiple pieces of evidence, including recent work with a mouse model, point to the fact that sensitization is mediated by exposure to certain hard ticks and increasingly we are aware of its globally widespread impact.

Summary

The oligosaccharide α-gal represents a novel allergen with several unusual clinical features. It has been recognized now on multiple continents and its clinical presentation can be quite variable. Moreover, efforts to delineate the mechanisms leading to α-gal sensitization may have ramifications for our broader understanding of type 2 immunity.



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Speech audiometric assessment of informational masking

Abstract

Background

In communication situations with multiple speakers, speech recognition is adversely affected by energetic masking (EM) and informational masking (IM). IM characterizes masking effects caused by irrelevant information from competing speakers. This work investigates an approach to assess IM based on the Oldenburg Sentence Test (OLSA). Furthermore, the influence of interaural time differences (ITD) and aging effects on IM are considered.

Materials and methods

IM was measured by superimposing two sentences from the OLSA. The beginning of the target sentence was indicated by the keyword “Stefan”. To segregate between target and masker sentences, ITDs from 50 to 400 μs were included. The participants were asked to selectively attend to the target sentence and repeat the spoken words. Potential factors associated with speech recognition results were assessed by an auditory measure of temporal fine structure and a neuropsychological profile. The study comprised 16 normal-hearing listeners between 18 and 77 years of age.

Results

Despite the clinically normal hearing participants, the analysis showed a significant relationship between speech recognition outcome and pure tone thresholds. All participants benefited from small ITDs between the target and masker sentence with regard to the unmasking of IM. The magnitude of unmasking could not be explained by any of the factors assessed in this study. Error analysis and the comparison with the literature reveal that the OLSA could be a useful tool to assess IM. Also in line with the current literature is the relationship between speech recognition outcome and pure tone thresholds, as well as the strong effect of ITDs on the release from IM.

Conclusion

Speech audiometric assessment of IM is of high relevance with regard to everyday communication situations. Due to its structure, the OLSA seems to be a useful tool for determining IM.



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The discovery of novel LPMO families with a new Hidden Markov model

Renewable biopolymers, such as cellulose, starch and chitin are highly resistance to enzymatic degradation. Therefore, there is a need to upgrade current degradation processes by including novel enzymes. Lytic...

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Buttercups focus light to heat their flowers and attract insects

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A special layer of cells inside the petals makes them act together like a parabolic reflector, focusing visible and infrared light on the flower centre

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The Medicaid Rebate: Changes in Oncology Drug Prices After the Affordable Care Act

Abstract

Background

Prescription drug spending is a significant component of Medicaid total expenditures. The Affordable Care Act (ACA) includes a provision that increases the Medicaid rebate for both brand-name and generic drugs. This study examines the extent to which oncology drug prices changed after the increase in the Medicaid rebate in 2010.

Methods

A pre-post study design was used to evaluate the correlation between the Medicaid rebate increase and oncology drug prices after 2010 using 2006–2013 State Drug Utilization Data.

Results

The results show that the average annual price of top-selling cancer drugs in 2006, adjusted for inflation and secular changes in drug prices, have increased by US$154 and US$235 for branded and competitive brand drugs, respectively, following the 2010 ACA; however, generic oncology drug prices showed no significant changes.

Conclusions

The findings from this study indicate that oncology drug prices have increased after the 2010 ACA, and suggest that pharmaceutical companies may have increased their drug prices to offset increases in Medicaid rebates.



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Forward Masking in Cochlear Implant Users: Electrophysiological and Psychophysical Data Using Pulse Train Maskers

Abstract

Electrical stimulation of auditory nerve fibers using cochlear implants (CI) shows psychophysical forward masking (pFM) up to several hundreds of milliseconds. By contrast, recovery of electrically evoked compound action potentials (eCAPs) from forward masking (eFM) was shown to be more rapid, with time constants no greater than a few milliseconds. These discrepancies suggested two main contributors to pFM: a rapid-recovery process due to refractory properties of the auditory nerve and a slow-recovery process arising from more central structures. In the present study, we investigate whether the use of different maskers between eCAP and psychophysical measures, specifically single-pulse versus pulse train maskers, may have been a source of confound.

In experiment 1, we measured eFM using the following: a single-pulse masker, a 300-ms low-rate pulse train masker (LTM, 250 pps), and a 300-ms high-rate pulse train masker (HTM, 5000 pps). The maskers were presented either at same physical current (Φ) or at same perceptual (Ψ) level corresponding to comfortable loudness. Responses to a single-pulse probe were measured for masker-probe intervals ranging from 1 to 512 ms. Recovery from masking was much slower for pulse trains than for the single-pulse masker. When presented at Φ level, HTM produced more and longer-lasting masking than LTM. However, results were inconsistent when LTM and HTM were compared at Ψ level. In experiment 2, masked detection thresholds of single-pulse probes were measured using the same pulse train masker conditions. In line with our eFM findings, masked thresholds for HTM were higher than those for LTM at Φ level. However, the opposite result was found when the pulse trains were presented at Ψ level.

Our results confirm the presence of slow-recovery phenomena at the level of the auditory nerve in CI users, as previously shown in animal studies. Inconsistencies between eFM and pFM results, despite using the same masking conditions, further underline the importance of comparing electrophysiological and psychophysical measures with identical stimulation paradigms.



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