722 research outputs found

    Inhibition of TXNRD or SOD1 overcomes NRF2-mediated resistance to β-lapachone

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    Alterations in the NRF2/KEAP1 pathway result in the constitutive activation of NRF2, leading to the aberrant induction of antioxidant and detoxification enzymes, including NQO1. The NQO1 bioactivatable agent β-lapachone can target cells with high NQO1 expression but relies in the generation of reactive oxygen species (ROS), which are actively scavenged in cells with NRF2/KEAP1 mutations. However, whether NRF2/KEAP1 mutations influence the response to β-lapachone treatment remains unknown. To address this question, we assessed the cytotoxicity of β-lapachone in a panel of NSCLC cell lines bearing either wild-type or mutant KEAP1. We found that, despite overexpression of NQO1, KEAP1 mutant cells were resistant to β-lapachone due to enhanced detoxification of ROS, which prevented DNA damage and cell death. To evaluate whether specific inhibition of the NRF2-regulated antioxidant enzymes could abrogate resistance to β-lapachone, we systematically inhibited the four major antioxidant cellular systems using genetic and/or pharmacologic approaches. We demonstrated that inhibition of the thioredoxin-dependent system or copper-zinc superoxide dismutase (SOD1) could abrogate NRF2-mediated resistance to β-lapachone, while depletion of catalase or glutathione was ineffective. Interestingly, inhibition of SOD1 selectively sensitized KEAP1 mutant cells to β-lapachone exposure. Our results suggest that NRF2/KEAP1 mutational status might serve as a predictive biomarker for response to NQO1-bioactivatable quinones in patients. Further, our results suggest SOD1 inhibition may have potential utility in combination with other ROS inducers in patients with KEAP1/NRF2 mutations

    Remodeling of the m6A RNA landscape in the conversion of acute lymphoblastic leukemia cells to macrophages

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    We thank CERCA Programme/Generalitat de Catalunya for institutional support. This work was supported by the Health Department PERIS-project no. SLT/002/16/00374 and AGAUR-projects no. 2017SGR1080 of the Catalan Government (Generalitat de Catalunya); Ministerio de Ciencia e Innovación (MCI), Agencia Estatal de Investigación (AEI) and European Regional Development Fund (ERDF) project no. RTI2018-094049-B-I00; the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (Grant agreement No. 743168); the Varda and Boaz Dotan Research Center in Hemato-oncology affiliated to the Tel Aviv University; the Cellex Foundation; and “la Caixa” Banking Foundation (LCF/PR/GN18/51140001). ME is an ICREA Research Professor.Peer Reviewed"Article signat per 12 autors/es: Alberto Bueno-Costa, David Piñeyro, Carlos A. García-Prieto, Vanessa Ortiz-Barahona, Laura Martinez-Verbo, Natalie A. Webster, Byron Andrews, Nitzan Kol, Chen Avrahami, Sharon Moshitch-Moshkovitz, Gideon Rechavi & Manel Esteller"Postprint (published version

    Virus like particles expressed in insect cells and mammalian cells as a plataform for the development of a Zika vaccine

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    The Zika virus (ZIKV) is an emergent mosquito-borne virus of the flaviviridae family that has caused severe challenges to global health since 2015. It causes Guillain-Barré syndrome and congenital malformations. Although case numbers have decreased, it is important to develop a vaccine for outbreaks. One alternative is the use of virus like particles (VLP) as vaccines. ZIKV is enveloped and is composed of three main structural proteins: enveloped (E), pre-membrane (M), and capsid. The main target of neutralizing antibodies is the E glycoprotein, which is glycosylated in some strains. The N-glycosylation profile is determined by the producer host cell. ZIKV has both insect and human hosts, and the N-glycosylation profile of the E protein produced by each host is expected to be different. It can be expected that glycosylation pattern has an impact on immune response against the E protein, but its effect on the immunogenicity against VLP of ZIKV has not been determined. For this reason, the present work seeks in the first instance, to design and produce VLP of ZIKV (ZIK VLP) in insect and human cells. To produce ZIK VLP, a chimeric gene was designed containing the M and E ZIKV genes fused to the transmembrane (TM) domain of Japanese encephalitis virus (JEV), ss- M-E (minus) ZIKV, TM JEV. After that, a recombinant baculovirus that contains the chimeric sequence was generated for VLP expression in insect cells. Production kinetics were followed, and the best conditions for VLP production were determined. For expression in human cells, the chimera was introduced into lentiviral vectors and was produced in HEK-293T/17 cells and used for the stable transfection of HEK-293 cells producing ZIKV VLP. High producing clones were selected by flow citometry. ZIK VLP were purified and characterized. In this work, strategies were developed for the efficient production of PPV in both systems, which can be used for further research. Ongoing studies are focused on determining the glycosylation profile of VLP expressed in both systems and on investigating the impact of glycosylation pattern of ZIK VLP immunogenicity in an animal model

    Intrahepatic injection of recombinant adeno-associated virus serotype 2 overcomes gender-related differences in liver transduction

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    The liver is an attractive organ for gene therapy because of its important role in many inherited and acquired diseases. Recombinant adeno-associated viruses (rAAVs) have been shown to be good candidates for liver gene delivery, leading to long-term gene expression. We evaluated the influence of the route of administration on rAAV-mediated liver transduction by comparing levels of luciferase expression in the livers of male and female mice after injection of rAAV serotype 2, using three different routes of administration: intravenous (IV), intraportal (IP), or direct intrahepatic (IH) injection. To determine transgene expression we used a noninvasive optical bioluminescence imaging system that allowed long-term in vivo analysis. After IV injection dramatic differences in liver transgene expression were observed, depending on gender. When IP injection was used the differences were reduced although they were still significant. Interestingly, direct intrahepatic injection of rAAV vectors was associated with the fastest and strongest onset of luciferase expression. Moreover, no gender differences in liver transduction were observed and luciferase expression was confined to the site of injection. Thus, direct intrahepatic injection of rAAV offers specific advantages, which support the potential of this route of administration for future clinical applications

    COVID-19 Impact Estimation on ICU Capacity at Andalusia, Spain, Using Artificial Intelligence

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    In early 2020, the world began to watch with caution the spread of an outbreak of pneumonia associated with a new coronavirus, called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which originated in late December 2019 in Wuhan City, Hubei Province, China. The rapid spread of this outbreak meant that in just one month more than 33 countries were infected with more than 85,200 cases

    Discovery and Early Evolution of ASASSN-19bt, the First TDE Detected by TESS

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    We present the discovery and early evolution of ASASSN-19bt, a tidal disruption event (TDE) discovered by the All-Sky Automated Survey for Supernovae (ASAS-SN) at a distance of d115d\simeq115 Mpc and the first TDE to be detected by TESS. As the TDE is located in the TESS Continuous Viewing Zone, our dataset includes 30-minute cadence observations starting on 2018 July 25, and we precisely measure that the TDE begins to brighten 8.3\sim8.3 days before its discovery. Our dataset also includes 18 epochs of Swift UVOT and XRT observations, 2 epochs of XMM-Newton observations, 13 spectroscopic observations, and ground data from the Las Cumbres Observatory telescope network, spanning from 32 days before peak through 37 days after peak. ASASSN-19bt thus has the most detailed pre-peak dataset for any TDE. The TESS light curve indicates that the transient began to brighten on 2019 January 21.6 and that for the first 15 days its rise was consistent with a flux t2\propto t^2 power-law model. The optical/UV emission is well-fit by a blackbody SED, and ASASSN-19bt exhibits an early spike in its luminosity and temperature roughly 32 rest-frame days before peak and spanning up to 14 days that has not been seen in other TDEs, possibly because UV observations were not triggered early enough to detect it. It peaked on 2019 March 04.9 at a luminosity of L1.3×1044L\simeq1.3\times10^{44} ergs s1^{-1} and radiated E3.2×1050E\simeq3.2\times10^{50} ergs during the 41-day rise to peak. X-ray observations after peak indicate a softening of the hard X-ray emission prior to peak, reminiscent of the hard/soft states in X-ray binaries.Comment: 23 pages, 14 figures, 5 tables. A machine-readable table containing the host-subtracted photometry presented in this manuscript is included as an ancillary fil

    Abundance of Pelagia noctiluca early life stages in the western Mediterranean Sea scales with surface chlorophyll

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    Pelagia noctiluca is the most successful and well-studied jellyfish in the Mediterranean Sea. This species tolerates a wide range of water temperatures and succeeds in low to medium food regimes, but factors driving its distribution and population dynamics remain poorly understood. Here we applied a multiscale analytical approach using survey data and a physical-biochemical coupled model to assess how environmental factors affect the 3-dimensional distribution and seasonal abundance of P. noctiluca early life stages. The surveys took place after the spring bloom, when warm water favors fecundity and growth, but food shortage limits the reproductive investment and early survival. We found that most early life stages of P. noctiluca remained above the shallow thermocline and upper mixed layer where temperature is warm. Their spatial distribution was positively correlated with surface chlorophyll concentration, and over 90% of the variation in interannual abundance was explained by basin-scale productivity in June. Warmer water during winter and spring seasons coupled with protracted spring blooms increase the population of P. noctiluca, and this explains the trend of increasing outbreaks observed in the western Mediterranean Sea over the past decades.Postprin

    Igf-1 facilitates extinction of conditioned fear

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    Insulin-like growth factor-1 (IGF-1) plays a key role in synaptic plasticity, spatial learning, and anxiety-like behavioral processes. While IGF-1 regulates neuronal firing and synaptic transmission in many areas of the central nervous system, its signaling and consequences on excitability, synaptic plasticity, and animal behavior dependent on the prefrontal cortex remain unexplored. Here, we show that IGF-1 induces a long-lasting depression of the medium and slow post-spike afterhyperpolarization (mAHP and sAHP), increasing the excitability of layer 5 pyramidal neurons of the rat infralimbic cortex. Besides, IGF-1 mediates a presynaptic long-term depression of both inhibitory and excitatory synaptic transmission in these neurons. The net effect of this IGF-1-mediated synaptic plasticity is a long-term potentiation of the postsynaptic potentials. Moreover, we demonstrate that IGF-1 favors the fear extinction memory. These results show novel functional consequences of IGF-1 signaling, revealing IGF-1 as a key element in the control of the fear extinction memor
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