184 research outputs found

    Noncanonical Role for the Host Vps4 AAA+ ATPase ESCRT Protein in the Formation of Tomato Bushy Stunt Virus Replicase

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    Assembling of the membrane-bound viral replicase complexes (VRCs) consisting of viral- and host-encoded proteins is a key step during the replication of positive-stranded RNA viruses in the infected cells. Previous genome-wide screens with Tomato bushy stunt tombusvirus (TBSV) in a yeast model host have revealed the involvement of eleven cellular ESCRT (endosomal sorting complexes required for transport) proteins in viral replication. The ESCRT proteins are involved in endosomal sorting of cellular membrane proteins by forming multiprotein complexes, deforming membranes away from the cytosol and, ultimately, pinching off vesicles into the lumen of the endosomes. In this paper, we show an unexpected key role for the conserved Vps4p AAA+ ATPase, whose canonical function is to disassemble the ESCRT complexes and recycle them from the membranes back to the cytosol. We find that the tombusvirus p33 replication protein interacts with Vps4p and three ESCRT-III proteins. Interestingly, Vps4p is recruited to become a permanent component of the VRCs as shown by co-purification assays and immuno-EM. Vps4p is co-localized with the viral dsRNA and contacts the viral (+)RNA in the intracellular membrane. Deletion of Vps4p in yeast leads to the formation of crescent-like membrane structures instead of the characteristic spherule and vesicle-like structures. The in vitro assembled tombusvirus replicase based on cell-free extracts (CFE) from vps4Δ yeast is highly nuclease sensitive, in contrast with the nuclease insensitive replicase in wt CFE. These data suggest that the role of Vps4p and the ESCRT machinery is to aid building the membrane-bound VRCs, which become nuclease-insensitive to avoid the recognition by the host antiviral surveillance system and the destruction of the viral RNA. Other (+)RNA viruses of plants and animals might also subvert Vps4p and the ESCRT machinery for formation of VRCs, which require membrane deformation and spherule formation

    Role of Viral RNA and Co-opted Cellular ESCRT-I and ESCRT-III Factors in Formation of Tombusvirus Spherules Harboring the Tombusvirus Replicase

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    Plus-stranded RNA viruses induce membrane deformations in infected cells in order to build viral replication complexes (VRCs). Tomato bushy stunt virus (TBSV) co-opts cellular ESCRT (endosomal sorting complexes required for transport) proteins to induce the formation of vesicle (spherule)-like structures in the peroxisomal membrane with tight openings toward the cytosol. In this study, using a yeast (Saccharomyces cerevisiae) vps23Δ bro1Δ double-deletion mutant, we showed that the Vps23p ESCRT-I protein (Tsg101 in mammals) and Bro1p (ALIX) ESCRT-associated protein, both of which bind to the viral p33 replication protein, play partially complementary roles in TBSV replication in cells and in cell extracts. Dual expression of dominant-negative versions of Arabidopsis homologs of Vps23p and Bro1p inhibited tombusvirus replication to greater extent than individual expression in Nicotiana benthamiana leaves. We also demonstrated the critical role of Snf7p (CHMP4), Vps20p, and Vps24p ESCRT-III proteins in tombusvirus replication in yeast and in vitro. Electron microscopic imaging of vps23Δ yeast revealed the lack of tombusvirus-induced spherule-like structures, while crescent-like structures are formed in ESCRT-III deletion yeasts replicating TBSV RNA. In addition, we also showed that the length of the viral RNA affects the sizes of spherules formed in N. benthamiana cells. The 4.8-kb genomic RNA is needed for the formation of spherules 66 nm in diameter, while spherules formed during the replication of the ∼600-nucleotide (nt)-long defective interfering RNA in the presence of p33 and p92 replication proteins are 42 nm. We propose that the viral RNA serves as a “measuring string” during VRC assembly and spherule formation

    Differentiated adsorption of thiobenzoic acid and thiobenzamide on silver nanoparticles determined by SERS spectroscopy.

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    Política de acceso abierto tomada de: https://v2.sherpa.ac.uk/id/publication/15140?template=romeo (Submitted version)Surface-enhanced Raman scattering of thiobenzoic acid and thiobenzamide have been recorded on three different silver colloids in order to find the chemical species responsible for the spectra and to detect differences in the adsorption with respect to their oxygen counterparts, benzoic acid and benzamide, respectively. Very significant and unexpected shifts of opposite sign between the Raman and SERS wavenumbers have been detected. By comparing the experimental and DFT calculated wavenumbers, it can be concluded that the acid is bonded to the metal as thiobenzoate through the sulfur atom with unidentate coordination. SERS spectra of thiobenzamide can be explained by assuming that it is adsorbed as azanion, like in the case of benzamide, linking to the metal through the sulfur and nitrogen atoms of the ionized thiocarboxamide group. In order to support these conclusions, B3LYP/LanL2DZ force field calculations for different complexes of silver cations with the thiobenzoate anion, the neutral thiobenzamide as well as its azanion have been carried out. Additionally, the 8a;nring mode is the most enhanced band in the SERS of both adsorbates pointing to the participation of a metal-to-molecule resonant charge transfer mechanism.Spanish MINECO/FEDER (CTQ2015-65816-R) Junta de Andalucía/FEDER (UMA18-FEDERJA-049 and P18-RT-4592) Ramón Areces Foundatio

    Persistent pain management in an oncology population through pain neuroscience education, a multimodal program: PaiNEd randomized clinical trial protocol

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    Pain is one of the most persistent symptoms after cancer treatment. The central nervous system can erroneously stay in its alarm phase, altering the pain experience of patients who have cancer. Pain neuroscience education (PNE) with multimodal approaches may benefit these patients.“Subvenciones para la Financiación de la Investigación, Desarrollo e Innovación (I+D+I) Biomédica y en Ciencias de la Salud, Consejería de Salud y Familias”, of the Andalusian Regional Government (PI-0171-2020

    Expression patterns for nicotinic acetylcholine receptor subunit genes in smoking-related lung cancers

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    Cigarette smoking is associated with increased risk for all histologic types of lung cancer, but why the strength of this association is stronger for squamous cell carcinoma than adenocarcinoma of the lung (SQC-L, ADC-L) is not fully understood. Because nicotine and tobacco-specific nitrosamines contribute to carcinogenesis by activating nicotinic acetylcholine receptors (nAChRs) on lung tumors and epithelial cells, we investigated whether differential expression of nAChR subtypes in these tumors could explain their different association with smoking. Expression of nAChR subunit genes in paired tumor and non-tumor lung specimens from 40 SQC-L and 38 ADC-L patients was analyzed by quantitative PCR. Compared to normal lung, both tumors share: i) transcriptional dysregulation of CHRNA3/CHRNA5/CHRNB4 (α3, α5, β4 subunits) at the chromosomal locus that predisposes to lung cancer; and ii) decreased expression of CHRFAM7A (dupα7 subunit); this last subunit negatively modulates α7-nAChR activity in oocytes. In contrast, CHRNA7 (α7 subunit) expression was increased in SQC-L, particularly in smokers and non-survivors, while CHRNA4 (α4 subunit) expression was decreased in ADC-L. Thus, over-representation of cancer-stimulating α7-nAChR in SQC-L, also potentiated by smoking, and underrepresentation of cancer-inhibiting α4β2-nAChR in ADC-L could explain the different tobacco influences on the tumorigenic process in each cancer typeThis study was supported by grants to C. Montiel and F. Arnalich from the Ministry of Economy, Industry and Competitiveness, Government of Spain (SAF2014-56623-R) and Foundation “Mutua Madrileña Investigación Biomédica” (FMM2011), Spain. A.B. is recipient of a fellowship (Beca FPI, Universidad Autónoma Madrid). J.L.C. and C.M.S. are recipients of fellowships (Beca FPU from Ministerio de Educación, Cultura y Deporte and Beca FPI from Ministry of Economy, Industry and Competitiveness, Government of Spain, respectively

    Discontinuation due to neuropsychiatric adverse events with efavirenz- and dolutegravir-based antiretroviral therapy: a comparative real-life study

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    Obervational study[Abstract] Objectives: Despite the high efficacy of antiretroviral treatment, no drug is free from adverse events (AEs). Efavirenz (EFV) and dolutegravir (DTG) are antiretroviral drugs for which neuropsychiatric adverse events (NPAEs) have been described. This study evaluated the safety and tolerability of DTG-based and EFV-based antiretroviral regimens in HIV-infected patients. Methods: A retrospective observational study was carried out in HIV-infected patients who started DTG- or EFV-based antiretroviral treatment from January 2008 to December 2018 at a reference hospital in north-western Spain. Epidemiological, clinical and immunovirological data were recorded. A statistical analysis was performed with SPSS software. Results: A total of 282 DTG- and 148 EFV-based therapies were initiated. During follow-up, statistically significant differences have been found between the rate of patients who discontinued DTG and EFV due to AEs (12.1% vs 35.8%, p<0.001) and the main AEs in both groups, NPAEs (8.2% vs 25.0%, p<0.001). Female gender (OR 2.610 (95% CI 1.327 to 5.133), p=0.005) was associated with discontinuations due to AEs. Patients with documented psychiatric disorders were at higher risk of discontinuation due to NPAEs (OR 4.782 (95% CI 1.190 to 19.220), p=0.027). The multivariate analysis showed a 61.2% risk reduction in benzodiazepine prescriptions in patients treated with DTG. In both groups, patients needed consultation and follow-up in the psychiatry unit (16.9% in the EFV group and 8.9% in the DTG group, p=0.021). Conclusions: We found a high rate of discontinuations due to AEs and NPAEs, prescription of benzodiazepines and a requirement for consultation in a psychiatric unit in both treatment groups, especially with EFV

    Renal profile of patients treated with elvitegravir/ cobicistat/emtricitabine/tenofovir alafenamide fumarate and dolutegravir/abacavir/lamivudine: 120-week results from a real-world cohort

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    [Abstract] Elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide fumarate (EVG/c/FTC/TAF) and dolutegravir/abacavir/lamivudine (DTG/ABC/3TC) are currently available for HIV patients. Objectives: This study evaluated modifications in the renal safety profile in a large real-world cohort of patients who had received EVG/c/FTC/TAF or DTG/ABC/3TC. Methods: A retrospective observational study of HIV-infected patients who received EVG/c/FTC/TAF or DTG/ABC/3TC between March 2015 and June 2019 at a reference hospital in north-western Spain was conducted. Epidemiological, clinical, immunovirological data and information regarding antiretroviral therapy were recorded. The statistical differences between treatments were calculated. Results: A total of 457 patients were evaluated, 266 using EVG/c/FTC/TAF and 191 using DTG/ABC/3TC. Up to week 120, serum creatinine improved in both study groups among experienced patients (EVG/c/FTC/TAF 1.01±0.24 vs 0.91±0.19, p<0.001; DTG/ABC/3TC 1.08±0.24 vs 1.02±0.31, p<0.001), while in naïve patients serum creatinine remained stable compared with baseline. Statistically significant differences were found in serum creatinine when comparing both treatments at week 48 in experienced (0.94±0.21 vs 1.09±0.28, p<0.001) and naïve patients (0.89±0.16 vs 1.06±0.20, p=0.001), and among experienced patients at week 120 (0.91±0.19 vs 1.02±0.31, p=0.015) for the EVG/c/FTC/TAF and DTG/ABC/3TC groups, respectively. During the follow-up, 39 patients in EVG/c/FTC/TAF and 33 in DTG/ABC/3TC (p=0.449) discontinued treatment. The main reason for stopping treatment was adverse events, which were similar in both groups. Conclusions: During the follow-up, patients experienced changes that were not clinically relevant in both treatment groups. Differences in renal events were not found

    Herramienta de evaluación de la calidad de los Materiales Educativos Digitales: perfiles de aplicación del profesor y del alumno

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    Este documento contiene dos adaptaciones de la herramienta de evaluación de la calidad de materiales educativos digitales (MED) del estándar UNE 71362 al profesor y al alumno que no son especialistas en Tecnologías ni en Accesibilidad con el fin de facilitar o mejorar la creación y selección de MED. Estos perfiles de aplicación no garantizan el cumplimiento del 100% de los criterios de calidad, por lo que no pueden ser usados como herramienta para certificar la calidad de los MED. Sin embargo, sí pueden ser usados para asegurar/comprobar con más facilidad determinados aspectos de la calidad

    Polarimetric imaging for the detection of synthetic models of SARS-CoV-2: A proof of concept

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    Objective: To conduct a proof-of-concept study of the detection of two synthetic models of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using polarimetric imaging. Approach: Two SARS-CoV-2 models were prepared as engineered lentiviruses pseudotyped with the G protein of the vesicular stomatitis virus, and with the characteristic Spike protein of SARS-CoV-2. Samples were prepared in two biofluids (saline solution and artificial saliva), in four concentrations, and deposited as 5-µL droplets on a supporting plate. The angles of maximal degree of linear polarization (DLP) of light diffusely scattered from dry residues were determined using Mueller polarimetry from87 samples at 405 nm and 514 nm. A polarimetric camera was used for imaging several samples under 380–420 nm illumination at angles similar to those of maximal DLP. Per-pixel image analysis included quantification and combination of polarization feature descriptors in 475 samples. Main results: The angles (from sample surface) of maximal DLP were 3° for 405 nm and 6° for 514 nm. Similar viral particles that differed only in the characteristic spike protein of the SARS-CoV-2, their corresponding negative controls, fluids, and the sample holder were discerned at 10-degree and 15-degree configurations. Significance: Polarimetric imaging in the visible spectrum may help improve fast, non-contact detection and identification of viral particles, and/or other microbes such as tuberculosis, in multiple dry fluid samples simultaneously, particularly when combined with other imaging modalities. Further analysis including realistic concentrations of real SARS-CoV-2 viral particles in relevant human fluids is required. Polarimetric imaging under visible light may contribute to a fast, cost-effective screening of SARS-CoV-2 and other pathogens when combined with other imaging modalities.12 página
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