837 research outputs found

    SUMO-2 promotes mRNA translation by enhancing interaction between eIF4E and eIF4G

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    Small ubiquitin-like modifier (SUMO) proteins regulate many important eukaryotic cellular processes through reversible covalent conjugation to target proteins. In addition to its many well-known biological consequences, like subcellular translocation of protein, subnuclear structure formation, and modulation of transcriptional activity, we show here that SUMO-2 also plays a role in mRNA translation. SUMO-2 promoted formation of the active eukaryotic initiation factor 4F (eIF4F) complex by enhancing interaction between Eukaryotic Initiation Factor 4E (eIF4E) and Eukaryotic Initiation Factor 4G (eIF4G), and induced translation of a subset of proteins, such as cyclinD1 and c-myc, which essential for cell proliferation and apoptosis. As expected, overexpression of SUMO-2 can partially cancel out the disrupting effect of 4EGI-1, a small molecule inhibitor of eIF4E/eIF4G interaction, on formation of the eIF4F complex, translation of the cap-dependent protein, cell proliferation and apoptosis. On the other hand, SUMO-2 knockdown via shRNA partially impaired cap-dependent translation and cell proliferation and promoted apoptosis. These results collectively suggest that SUMO-2 conjugation plays a crucial regulatory role in protein synthesis. Thus, this report might contribute to the basic understanding of mammalian protein translation and sheds some new light on the role of SUMO in this process. © 2014 Chen et al

    The impact of assisted reproductive technology and ovulation induction on breech presentation: A whole of population-based cohort study.

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    AIMS: Multiple studies have suggested a likely association between breech presentation and assisted reproductive technology (ART) for conception. The aims were to determine whether conception via in vitro fertilisation (IVF) and ovulation induction (OI) is associated with fetal malpresentation at birth and to ascertain what mediating factors most significantly contribute to fetal malpresentation. METHODS: This whole-population-based cohort study included 355 990 singleton pregnancies born in Queensland, Australia, between July 2012 and July 2018. Multinomial logistic regression models estimated the adjusted odds of breech, transverse/shoulder and face/brow malpresentations in pregnancies conceived via spontaneous conception, OI (OI group) and IVF with or without intracytoplasmic sperm injection (ART group). RESULTS: After adjustment for potential confounding factors, breech presentation occurred approximately 20% more often in singleton pregnancies conceived via both ART (adjusted odds ratio: 1.20, 95% confidence interval: 1.10-1.30, P < 0.001) and OI (1.21, 95% confidence interval: 1.04-1.39, P < 0.05). No significant associations were observed between the three modes of conception and transverse/shoulder or face/brow presentations. Low birthweight was found to be the most significant mediating factor for breech presentation in pregnancies conceived via ART and OI. CONCLUSIONS: Similar levels of increased odds of breech presentation are present in pregnancies conceived via OI and ART, suggesting a shared underlying mechanism for the aetiology of breech presentation. For women who are considering or have conceived via these methods, counselling with respect to this increased risk is recommended

    An overview of the CANVAS Program and CREDENCE trial: The primary outcomes and key clinical implications for those managing patients with type 2 diabetes

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    Aims: To provide an overview of the primary outcomes and key clinical implications of the CANVAS Program and CREDENCE trial, which were event-driven, double-blind randomized controlled trials that established the efficacy and safety of canagliflozin in those with type 2 diabetes (T2D) and high cardiovascular risk (CV) or albuminuric chronic kidney disease (CKD). Methods and Results: The CANVAS programme (CANVAS and CANVAS-R trials) randomized 10 142 people with T2D and high CV risk to canagliflozin or placebo and followed them for a median of 126 weeks. The primary efficacy outcome was met, with canagliflozin treatment associated with a 14% reduction in major adverse CV events (hazard ratio [HR] 0.86, 95% confidence interval [CI] 0.75 to 0.97; p < 0.001) as compared to placebo. The CREDENCE trial randomized 4401 individuals with T2D and albuminuric CKD to canagliflozin or placebo and followed them for 109 weeks. The CREDENCE trial also met its primary endpoint; canagliflozin treatment was associated with a 30% reduction in the composite of kidney failure, sustained doubling of serum creatinine level, or death from kidney or CV causes (HR 0.70, 95% CI 0.59 to 0.82; p < 0.001). Substantial reductions in hospitalization for heart failure (CANVAS: HR 0.67, 95% CI 0.52 to 0.87; CREDENCE: HR 0.61, 95% CI 0.47 to 0.80) and other key CV and kidney outcomes were also identified. Relative clinical benefits were consistent across subgroups defined by baseline age, sex, kidney function and history of CV disease but absolute benefits were greatest in those at highest baseline risk. Total serious adverse events were less common with canagliflozin treatment. Concerns about amputation and fracture risk observed in the CANVAS Program were not seen in CREDENCE and appear to have been spurious chance findings. Conclusion: Canagliflozin reduced important CV, kidney and mortality outcomes in those with T2D and high CV risk or CKD across diverse patient groups, with a good safety profile. Taken together with the other sodium-glucose cotransporter-2 inhibitor CV and renal outcomes trials, these landmark findings have changed the treatment landscape for patients worldwide

    A novel hybrid integration model using support vector machines and random subspace for weather-triggered landslide susceptibility assessment in the Wuning area (China)

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    © Springer-Verlag GmbH Germany 2017. This study proposed a hybrid modeling approach using two methods, support vector machines and random subspace, to create a novel model named random subspace-based support vector machines (RSSVM) for assessing landslide susceptibility. The newly developed model was then tested in the Wuning area, China, to produce a landslide susceptibility map. With the purpose of achieving the objective of the study, a spatial dataset was initially constructed that includes a landslide inventory map consisting of 445 landslide regions. Then, various landslide-influencing factors were defined, including slope angle, aspect, altitude, topographic wetness index, stream power index, sediment transport index, soil, lithology, normalized difference vegetation index, land use, rainfall, distance to roads, distance to rivers, and distance to faults. Next, the result of the RSSVM model was validated using statistical index-based evaluations and the receiver operating characteristic curve approach. Then, to evaluate the performance of the suggested RSSVM model, a comparison analysis was performed to other existing approaches such as artificial neural network, Naïve Bayes (NB) and support vector machine (SVM). In general, the performance of the RSSVM model was better than the other models for spatial prediction of landslide susceptibility. The AUC results of the applied models are as follows: RSSVM (AUC = 0.857), followed by MLP (AUC = 0.823), SVM (AUC = 0.814) and NB (AUC = 0.783). The present study indicates that RSSVM can be used for landslide susceptibility evaluation, and the results are very useful for local governments and people living in the Wuning area

    Location of the CD8 T Cell Epitope within the Antigenic Precursor Determines Immunogenicity and Protection against the Toxoplasma gondii Parasite

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    CD8 T cells protect the host from disease caused by intracellular pathogens, such as the Toxoplasma gondii (T. gondii) protozoan parasite. Despite the complexity of the T. gondii proteome, CD8 T cell responses are restricted to only a small number of peptide epitopes derived from a limited set of antigenic precursors. This phenomenon is known as immunodominance and is key to effective vaccine design. However, the mechanisms that determine the immunogenicity and immunodominance hierarchy of parasite antigens are not well understood.Here, using genetically modified parasites, we show that parasite burden is controlled by the immunodominant GRA6-specific CD8 T cell response but not by responses to the subdominant GRA4- and ROP7-derived epitopes. Remarkably, optimal processing and immunodominance were determined by the location of the peptide epitope at the C-terminus of the GRA6 antigenic precursor. In contrast, immunodominance could not be explained by the peptide affinity for the MHC I molecule or the frequency of T cell precursors in the naive animals. Our results reveal the molecular requirements for optimal presentation of an intracellular parasite antigen and for eliciting protective CD8 T cells. © 2013 Feliu et al

    The Role of miR-30d-5p in Neutrophil-Derived Exosomes in Promoting Systemic Lupus Erythematosus

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    A-Qiong Chen, A-Xiao Pan, Juan Liu, Dan-Qiong Zhang, Jia-Yuan Chen, Jin Zhang Department of Rheumatology and Clinical Immunology, Ningbo Medical Center Lihuili Hospital, The Affiliated Li Huili Hospital, Ningbo University, Ningbo, People’s Republic of ChinaCorrespondence: Jin Zhang, Email [email protected]: In this study, we investigated the role of neutrophil-derived exosomal miR-30d-5p in systemic lupus erythematosus (SLE).Methods: We extracted exosomes from the neutrophils collected from SLE patients and healthy donors and analyzed the relative level of miR-30d-5p. The exosomes were characterized by transmission electron microscopy (TEM) and nanoparticle tracking analysis (NTA). We mimicked SLE using MRL/lpr mice and treated the mice with exosomes and miR-30d-5p inhibitors. The RNA level of miR-30d-5p in serum of mice was analyzed by qPCR. The images of spleen were captured to evaluate splenomegaly. The serum levels of anti-nuclear antibodies (ANAs), total IgG, total IgM, and anti-dsDNA IgG were measured by ELISA. The kidney injury was analyzed by albumin level, haematoxylin and eosin (HE) staining, active index, and chronic index. The T cell differentiation and B cell activation were detected by flow cytometry. For T follicular helper (TfH) cell analysis, cells were stained with anti-CXCR5 and anti-PD-1 antibodies. Levels of inflammatory cytokines in serum were measured by ELISA.Results: The exosomes from SLE patients showed significant higher level of miR-30d-5p. Treatment with neutrophil-exosomes enhanced the degree of splenomegaly in MRL/lpr mice and production of anti-nuclear antibodies (ANAs), total IgG, total IgM, and anti-dsDNA IgG, which was repressed by miR-30d-5p inhibitor. Compared with MRL/lpr mice, mice treated with neutrophil-derive exosomes exhibited a notable increase of proteinuria and infiltration of lymphocytes in kidney, whereas inhibition of miR-30d-5p reduced this elevation. Exosome treatment elevated the number of IL17+ Th17 cells, CXCR5+PD-1+ TfH cells, reduced the portion of Foxp3+ Treg cells, and elevated B cells, and inhibition of miR-30d-5p reversed these effects.Conclusion: The neutrophils from SLE exhibited higher level of miR-30d-5p, and inhibition of miR-30d-5p could suppress the T cell and B cell activation, reduce inflammatory cytokine and antibodies production, and alleviate the lupus nephritis during SLE.Keywords: systemic lupus erythematosus, neutrophil, exosomes, miR-30d-5p, T cell, B cel

    The origin of animals: can molecular clocks and the fossil record be reconciled?

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    The evolutionary emergence of animals is one of the most significant episodes in the history of life, but its timing remains poorly constrained. Molecular clocks estimate that animals originated and began diversifying over 100 million years before the first definitive metazoan fossil evidence in the Cambrian. However, closer inspection reveals that clock estimates and the fossil record are less divergent than is often claimed. Modern clock analyses do not predict the presence of the crown-representatives of most animal phyla in the Neoproterozoic. Furthermore, despite challenges provided by incomplete preservation, a paucity of phylogenetically informative characters, and uncertain expectations of the anatomy of early animals, a number of Neoproterozoic fossils can reasonably be interpreted as metazoans. A considerable discrepancy remains, but much of this can be explained by the limited preservation potential of early metazoans and the difficulties associated with their identification in the fossil record. Critical assessment of both records may permit better resolution of the tempo and mode of early animal evolution.JAC and AGL acknowledge support from Natural Environment Research Council (NERC) Fellowships [grant numbers NE/J018325/1 and NE/L011409/1]. SB and JAC acknowledge funding from the Danish National Research Foundation [DNRF53] and the Swedish Research Council [2013-4290]. PCJD was supported by a Royal Society Wolfson Merit Award, a Leverhulme Trust Research Fellowship and a NERC standard grant [NE/F00348X/1]

    Predicting clinical outcomes in Glioblastoma: an application of topological and functional data analysis

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    Glioblastoma multiforme (GBM) is an aggressive form of human brain cancer that is under active study in the field of cancer biology. Its rapid progression and the relative time cost of obtaining molecular data make other readily available forms of data, such as images, an important resource for actionable measures in patients. Our goal is to use information given by medical images taken from GBM patients in statistical settings. To do this, we design a novel statistic—the smooth Euler characteristic transform (SECT)—that quantifies magnetic resonance images of tumors. Due to its well-defined inner product structure, the SECT can be used in a wider range of functional and nonparametric modeling approaches than other previously proposed topological summary statistics. When applied to a cohort of GBM patients, we find that the SECT is a better predictor of clinical outcomes than both existing tumor shape quantifications and common molecular assays. Specifically, we demonstrate that SECT features alone explain more of the variance in GBM patient survival than gene expression, volumetric features, and morphometric features. The main takeaways from our findings are thus 2-fold. First, they suggest that images contain valuable information that can play an important role in clinical prognosis and other medical decisions. Second, they show that the SECT is a viable tool for the broader study of medical imaging informatics. Supplementary materials for this article, including a standardized description of the materials available for reproducing the work, are available as an online supplement

    QCD and strongly coupled gauge theories : challenges and perspectives

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    We highlight the progress, current status, and open challenges of QCD-driven physics, in theory and in experiment. We discuss how the strong interaction is intimately connected to a broad sweep of physical problems, in settings ranging from astrophysics and cosmology to strongly coupled, complex systems in particle and condensed-matter physics, as well as to searches for physics beyond the Standard Model. We also discuss how success in describing the strong interaction impacts other fields, and, in turn, how such subjects can impact studies of the strong interaction. In the course of the work we offer a perspective on the many research streams which flow into and out of QCD, as well as a vision for future developments.Peer reviewe
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