10,490 research outputs found

    Inhibition of cellular protein secretion by norwalk virus nonstructural protein p22 requires a mimic of an endoplasmic reticulum export signal.

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    Protein trafficking between the endoplasmic reticulum (ER) and Golgi apparatus is central to cellular homeostasis. ER export signals are utilized by a subset of proteins to rapidly exit the ER by direct uptake into COPII vesicles for transport to the Golgi. Norwalk virus nonstructural protein p22 contains a YXΦESDG motif that mimics a di-acidic ER export signal in both sequence and function. However, unlike normal ER export signals, the ER export signal mimic of p22 is necessary for apparent inhibition of normal COPII vesicle trafficking, which leads to Golgi disassembly and antagonism of Golgi-dependent cellular protein secretion. This is the first reported function for p22. Disassembly of the Golgi apparatus was also observed in cells replicating Norwalk virus, which may contribute to pathogenesis by interfering with cellular processes that are dependent on an intact secretory pathway. These results indicate that the ER export signal mimic is critical to the antagonistic function of p22, shown herein to be a novel antagonist of ER/Golgi trafficking. This unique and well-conserved human norovirus motif is therefore an appealing target for antiviral drug development

    Energy use in Urban Transport sector within the Sustainable Energy Action Plans (SEAPs) of three Italian Big Cities

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    Promising Renewable Energy solutions could be installed in cities, but they require specific morphological conditions as well as architectural integration. Transport sector is still neglected from a strong policy initiative. A first attempt along with a defined framework to attract economic resources as well as interested stakeholders is the Covenant of Mayors (CoM). Within this agreement, the Municipality has to design a plan, the so-called Sustainable Energy Action Plan (SEAP). The plan must contain a clear outline of the strategy and relative actions to be taken by the local authority to reach its commitments in 2020, in terms of sustainability goals set by EU 20-20-20. The aim of this paper is to discuss and evaluate the differences of fuel usage and transport sector interaction in Italian urban scenarios, taking into account geographical and morphological constraints, and to compare the forecasts for 2020 and 2030scenarios, in accordance with European and National laws in force

    A red/far-red light-responsive bi-stable toggle switch to control gene expression in mammalian cells

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    Growth and differentiation of multicellular systems is orchestrated by spatially restricted gene expression programs in specialized subpopulations. The targeted manipulation of such processes by synthetic tools with high-spatiotemporal resolution could, therefore, enable a deepened understanding of developmental processes and open new opportunities in tissue engineering. Here, we describe the first red/far-red light-triggered gene switch for mammalian cells for achieving gene expression control in time and space. We show that the system can reversibly be toggled between stable on- and off-states using short light pulses at 660 or 740 nm. Red light-induced gene expression was shown to correlate with the applied photon number and was compatible with different mammalian cell lines, including human primary cells. The light-induced expression kinetics were quantitatively analyzed by a mathematical model. We apply the system for the spatially controlled engineering of angiogenesis in chicken embryos. The system's performance combined with cell- and tissue-compatible regulating red light will enable unprecedented spatiotemporally controlled molecular interventions in mammalian cells, tissues and organisms

    Solar energy technologies in sustainable energy action plans of italian big cities

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    Cities, accounting for more than 3/4 of global final energy consumption, are equipping themselves with governance tools to improve energy efficiency. In Europe, urban energy policy has adopted, only recently and voluntarily, the Sustainable Energy Action Plans (SEAP), following the European Strategy 20-20-20. Italy, country most sensitive among European ones, accounts for 53% of SEAPs signatories. In order to evaluate how urban energy system in Italy can match sustainability European goals, it is necessary to analyse the technological options promoted by the energy policies for the urban environment. The paper presents the state-of-art of Urban Energy Planning in Italy, focusing on the implementation of Solar Energy technologies, and their role in new urban energy strategy instruments, i.e. SEAP, to promote renewables deployment. Carbon emission avoidance interventions planned by Italian big cities were analysed, highlighting the chosen Solar Energy technology. The aim of this paper is to discuss and evaluate the differences of solar energy harvesting in Italian urban scenarios, taking into account geographical and morphological constraints, and to compare the forecasts for 2020 and 2030scenarios, in accordance with European and National laws in force

    Type three secretion system-mediated escape of Burkholderia pseudomallei into the host cytosol is critical for the activation of NFκB.

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    BackgroundBurkholderia pseudomallei is the causative agent of melioidosis, a potentially fatal disease endemic in Southeast Asia and Northern Australia. This Gram-negative pathogen possesses numerous virulence factors including three "injection type" type three secretion systems (T3SSs). B. pseudomallei has been shown to activate NFκB in HEK293T cells in a Toll-like receptor and MyD88 independent manner that requires T3SS gene cluster 3 (T3SS3 or T3SSBsa). However, the mechanism of how T3SS3 contributes to NFκB activation is unknown.ResultsKnown T3SS3 effectors are not responsible for NFκB activation. Furthermore, T3SS3-null mutants are able to activate NFκB almost to the same extent as wildtype bacteria at late time points of infection, corresponding to delayed escape into the cytosol. NFκB activation also occurs when bacteria are delivered directly into the cytosol by photothermal nanoblade injection.ConclusionsT3SS3 does not directly activate NFκB but facilitates bacterial escape into the cytosol where the host is able to sense the presence of the pathogen through cytosolic sensors leading to NFκB activation

    Simvastatin inhibits TLR8 signaling in primary human monocytes and spontaneous TNF production from rheumatoid synovial membrane cultures

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    Simvastatin has been shown to have anti-inflammatory effects that are independent of its serum cholesterol lowering action, but the mechanisms by which these anti-inflammatory effects are mediated have not been elucidated. To explore the mechanism involved, the effect of simvastatin on Toll-like receptor (TLR) signalling in primary human monocytes was investigated. A short pre-treatment with simvastatin dose-dependently inhibited the production of tumor necrosis factor-α (TNF) in response to TLR8 (but not TLRs 2, 4, or 5) activation. Statins are known inhibitors of the cholesterol biosynthetic pathway, but intriguingly TLR8 inhibition could not be reversed by addition of mevalonate or geranylgeranyl pyrophosphate; downstream products of cholesterol biosynthesis. TLR8 signalling was examined in HEK 293 cells stably expressing TLR8, where simvastatin inhibited IKKα/β phosphorylation and subsequent NF-κB activation without affecting the pathway to AP-1. Since simvastatin has been reported to have anti-inflammatory effects in RA patients and TLR8 signalling contributes to TNF production in human RA synovial tissue in culture, simvastatin was tested in these cultures. Simvastatin significantly inhibited the spontaneous release of TNF in this model which was not reversed by mevalonate. Together, these results demonstrate a hitherto unrecognized mechanism of simvastatin inhibition of TLR8 signalling that may in part explain its beneficial anti-inflammatory effects

    Toxoplasma gondii profilin does not stimulate an innate immune response through bovine or human TLR5

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    Toxoplasma gondii is responsible for one of the most prevalent infections in people. T. gondii profilin (TgPr) is a protein integral to parasite movement and cellular invasion. Murine TLR has been described to bind TgPr. Furthermore, more recently, human TLR5 has been described to recognise recombinant TgPr, as well as bacterial flagellin. In addition to infections in humans, T. gondii infects farm animals, but little information is available about its innate recognition. We aimed to investigate whether, similarly to their human orthologue, bovine and porcine TLR5 could also be stimulated by TgPr by using a combination of reporter cell lines expressing full length TLR5 from each species as well as primary cells. Although human and bovine TLR5-transfected cells responded to flagellin, no response was detected upon stimulation with profilin. Furthermore, TgPr failed to elicit IL-6 secretion in human peripheral blood mononuclear cells and CD14þ monocytes. In contrast, exposure of RAW cells, known to express TLR11 to TgPr, slightly increased the IL-6 response. Our data cast doubts on the possibility that profilin is a specific ligand for human TLR5 and bovine TLR5. This leaves the immunogenic properties of this potential target antigen uncharacterised outside of the murine system

    Climate change: is Southeast Asia up to the challenge?: foreword

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    Activation of an Estrogen/ Estrogen Receptor Signaling by BIG3 Through Its Inhibitory Effect on Nuclear Transport of PHB2/REA in Breast Cancer

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    Breast cancer is known to be a hormone-dependent disease, and estrogens through an interaction with estrogen receptor (ER) enhance the proliferative and metastatic activity of breast tumor cells. Here we show a critical role of transactivation of BIG3, brefeldin A-inhibited guanine nucleotide-exchange protein 3, in activation of the estrogen/ER signaling in breast cancer cells. Knocking-down of BIG3 expression with small-interfering RNA (siRNA) drastically suppressed the growth of breast cancer cells. Subsequent co-immunoprecipitation and immunoblotting assays revealed an interaction of BIG3 with prohibitin 2/repressor of estrogen receptor activity (PHB2/REA). When BIG3 was absent, stimulation of estradiol caused the translocation of PHB2/REA to the nucleus, enhanced the interaction of PHB2/REA and ER[alpha], and resulted in suppression of the ER[alpha]; transcriptional activity. On the other hand, when BIG3 was present, BIG3 trapped PHB2/REA in cytoplasm and inhibited its nuclear translocation, and caused enhancement of ER[alpha]; transcriptional activity. Our results imply that BIG3 overexpression is one of the important mechanisms causing the activation of the estrogen/ER[alpha]; signaling pathway in the hormone-related growth of breast cancer cells

    A program to evaluate a control system based on feedback of aerodynamic pressure differentials, part 1

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    The use of pressure differentials in a flight control system was evaluated. The pressure profile around the test surface was determined using two techniques: (1) windtunnel data (actual); and (2) NASA/Langley Single Element Airfoil Computer Program (theoretical). The system designed to evaluate the concept of using pressure differentials is composed of a sensor drive and power amplifiers, actuator, position potentiometer, and a control surface. The characteristics (both desired and actual) of the system and each individual component were analyzed. The desired characteristics of the system as a whole are given. The flight control system developed, the testing procedures and data reduction methods used, and theoretical frequency response analysis are described
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