Guanosine inhibits hepatitis C virus replication and increases indel frequencies, associated with altered intracellular nucleotide pools

In the course of experiments aimed at deciphering the inhibition mechanism of mycophenolic acid and ribavirin in hepatitis C virus (HCV) infection, we observed an inhibitory effect of the nucleoside guanosine (Gua). Here, we report that Gua, and not the other standard nucleosides, inhibits HCV replication in human hepatoma cells. Gua did not directly inhibit the in vitro polymerase activity of NS5B, but it modified the intracellular levels of nucleoside di- and tri-phosphates (NDPs and NTPs), leading to deficient HCV RNA replication and reduction of infectious progeny virus production. Changes in the concentrations of NTPs or NDPs modified NS5B RNA polymerase activity in vitro, in particular de novo RNA synthesis and template switching. Furthermore, the Gua-mediated changes were associated with a significant increase in the number of indels in viral RNA, which may account for the reduction of the specific infectivity of the viral progeny, suggesting the presence of defective genomes. Thus, a proper NTP:NDP balance appears to be critical to ensure HCV polymerase fidelity and minimal production of defective genomes.CP is supported by the Miguel Servet program (grants CP14/00121 and CP19/00001) of the Instituto de Salud Carlos III cofinanced by FEDER. CP has received funding from Ministerio de Ciencia, Innovacio´n y Universidades (grant BFU2017-91384-EXP), from Instituto de Salud Carlos III (grants PI18/00210 and PI21/00139), from Fundación La Marato´ (grant 525/C/2021), and from CSIC (grant CSIC-COV19-014). ED has received funding from CIBERehd (Centro de Investigación en Red de Enfermedades Hepáticas y Digestivas, Instituto de Salud Carlos III), from Ministerio de Economía y Competitividad (grants SAF2014-52400-R, SAF2017-87846-R, and PID2020-113888RB-I00), and from Comunidad de Madrid/FEDER (grants S2013/ABI-2906 PLATESA, and S2018/BAA-4370 PLATESA2). AM has received funding from Ministerio de Economía y Competitividad (grants SAF2016-80451-P, PID2019-106068GB-I00, EQC2018-004420-P, and EQC2018-004631-P), and Plan Propio of Universidad de Castilla-La Mancha. A.G-P and L.DM have received funding from Consejería de Transformación Económica, Industria, Conocimiento y Universidades, Junta de Andalucía, cofinanced by FEDER and FSE (grants BIO-264, and P10-CVI-6561) and Plan Propio of Universidad de Málaga.Peer reviewe

Identification of eQTLs associated with lipid metabolism in Longissimus dorsi muscle of pigs with different genetic backgrounds

Altres ajuts: Ph.D grant from the Generalitat de Catalunya (ECO/1788/2014) i CERCA Programme/Generalitat de CatalunyaIntramuscular fat content and its fatty acid composition affect porcine meat quality and its nutritional value. The present work aimed to identify genomic variants regulating the expression in the porcine muscle (Longissimus dorsi) of 45 candidate genes for lipid metabolism and fatty acid composition in three experimental backcrosses based on the Iberian breed. Expression genome-wide association studies (eGWAS) were performed between the muscle gene expression values, measured by real-time quantitative PCR, and the genotypes of 38,426 SNPs distributed along all chromosomes. The eGWAS identified 186 eSNPs located in ten Sus scrofa regions and associated with the expression of ACSM5, ACSS2, ATF3, DGAT2, FOS and IGF2 (FDR < 0.05) genes. Two expression quantitative trait loci (eQTLs) for IGF2 and ACSM5 were classified as cis-acting eQTLs, suggesting a mutation in the same gene affecting its expression. Conversely, ten eQTLs showed trans-regulatory effects on gene expression. When the eGWAS was performed for each backcross independently, only three common trans-eQTL regions were observed, indicating different regulatory mechanisms or allelic frequencies among the breeds. In addition, hotspot regions regulating the expression of several genes were detected. Our results provide new data to better understand the functional regulatory mechanisms of lipid metabolism genes in muscle

Akt phosphorylation of HCV NS5B regulates polymerase activity and HCV infection

Hepatitis C virus (HCV) is a single-stranded RNA virus of positive polarity [ssRNA(+)] that replicates its genome through the activity of one of its proteins, called NS5B. This viral protein is responsible for copying the positive-polarity RNA genome into a negative-polarity RNA strand, which will be the template for new positive-polarity RNA genomes. The NS5B protein is phosphorylated by cellular kinases, including Akt. In this work, we have identified several amino acids of NS5B that are phosphorylated by Akt, with positions S27, T53, T267, and S282 giving the most robust results. Site-directed mutagenesis of these residues to mimic (Glu mutants) or prevent (Ala mutants) their phosphorylation resulted in a reduced NS5B in vitro RNA polymerase activity, except for the T267E mutant, the only non-conserved position of all those that are phosphorylated. In addition, in vitro transcribed RNAs derived from HCV complete infectious clones carrying mutations T53E/A and S282E/A were transfected in Huh-7.5 permissive cells, and supernatant viral titers were measured at 6 and 15 days post-transfection. No virus was rescued from the mutants except for T53A at 15 days post-transfection whose viral titer was statistically lower as compared to the wild type. Therefore, phosphorylation of NS5B by cellular kinases is a mechanism of viral polymerase inactivation. Whether this inactivation is a consequence of interaction with cellular kinases or a way to generate inactive NS5B that may have other functions are questions that need further experimental workMinisterio de Ciencia, Innovación y Universidades (MCIU), PI18/00210 from Instituto de Salud Carlos III, and S2018/BAA-4370 (PLATESA2 from Comunidad de Madrid/FEDER). CP was supported by the Miguel Servet program of the Instituto de Salud Carlos III (CPII19/00001), cofinanced by the European Regional Development Fund (ERDF). CG-C was supported by the predoctoral contract PRE2018-083422 from MCIU. CIBERehd (Centro de Investigación en Red de Enfermedades Hepáticas y Digestivas) was funded by the Instituto de Salud Carlos III. Institutional grants from the Fundación Ramón Areces and Banco Santander to the CBMS

Apoptotic cells subjected to cold/warming exposure disorganize apoptotic microtubule network and undergo secondary necrosis

Apoptotic microtubule network (AMN) is organized during apoptosis, forming a cortical structure beneath the plasma membrane which plays a critical role in preserving cell morphology and plasma membrane integrity. The aim of this study was to examine the effect of cold/warming exposure on apoptotic microtubules and plasma membrane integrity during the execution phase of apoptosis. We demonstrated in camptothecin-induced apoptotic H460 cells that cold/warming exposure disorganized apoptotic microtubules and allowed the access of active caspases to the cellular cortex and the cleavage of essential proteins in the preservation of plasma membrane permeability. Cleavage of cellular cortex and plasma membrane proteins, such as ¿-spectrin, paxilin, focal adhesion kinase and calcium ATPase pump (PMCA-4) involved in cell calcium extrusion resulted in increased plasma permeability and calcium overload leading apoptotic cells to secondary necrosis. The essential role of caspase-mediated cleavage in this process was demonstrated because the addition of the pan-caspase inhibitor z-VAD during cold/warming exposure that induces AMN depolymerization avoided the cleavage of cortical and plasma membrane proteins and prevented apoptotic cells to undergo secondary necrosis. Likewise, apoptotic microtubules stabilization by taxol during cold/warming exposure also prevented cellular cortex and plasma membrane protein cleavage and secondary necrosis. Furthermore, microtubules stabilization or caspase inhibition during cold/warming exposure was also critical for proper phosphatidylserine externalization and apoptotic cell clearance by macrophages. These results indicate that cold/warming exposure of apoptotic cells induces secondary necrosis which can be prevented by both, microtubule stabilization or caspase inhibition.This work was supported by FIS PI10/00543 Grant, FIS EC08/00076 Grant, Ministerio de Sanidad, Spain and Fondo Europeo de Desarrollo Regional (FEDER-Unión Europea), SAS 111242 Grant, Servicio Andaluz de Salud-Junta de Andalucía, Proyecto de Investigación de Excelencia de la Junta de Andalucía CTS-5725, and by Asociación de Enfermos de Patología Mitocondrial (AEPMI).Peer Reviewe

Stabilization of apoptotic cells: generation of zombie cells

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.Apoptosis is characterized by degradation of cell components but plasma membrane remains intact. Apoptotic microtubule network (AMN) is organized during apoptosis forming a cortical structure beneath plasma membrane that maintains plasma membrane integrity. Apoptotic cells are also characterized by high reactive oxygen species (ROS) production that can be potentially harmful for the cell. The aim of this study was to develop a method that allows stabilizing apoptotic cells for diagnostic and therapeutic applications. By using a cocktail composed of taxol (a microtubule stabilizer), Zn2+ (a caspase inhibitor) and coenzyme Q10 (a lipid antioxidant), we were able to stabilize H460 apoptotic cells in cell cultures for at least 72 h, preventing secondary necrosis. Stabilized apoptotic cells maintain many apoptotic cell characteristics such as the presence of apoptotic microtubules, plasma membrane integrity, low intracellular calcium levels and mitochondrial polarization. Apoptotic cell stabilization may open new avenues in apoptosis detection and therapy.This work was supported by FIS PI10/00543 grant, Ministerio de Sanidad, Spain, and Fondo Europeo de Desarrollo Regional (FEDER-Unión Europea), SAS 111242 grant, Servicio Andaluz de Salud-Junta de Andalucía, Proyecto de Investigación de Excelencia de la Junta de Andalucía CTS-5725, BFU2012-38208 and by AEPMI (Asociación de Enfermos de Patología Mitocondrial).Peer Reviewe

Amitriptyline induces mitophagy that precedes apoptosis in human HepG2 cells

Systemic treatments for hepatocellular carcinoma (HCC) have been largely unsuccessful. This study investigated the antitumoral activity of Amitriptyline, a tricyclic antidepressant, in hepatoma cells. Amitriptyline-induced toxicity involved early mitophagy activation that subsequently switched to apoptosis. Amitriptyline induced mitochondria dysfunction and oxidative stress in HepG2 cells. Amitriptyline specifically inhibited mitochondrial complex III activity that is associated with decreased mitochondrial membrane potential (ΔΨm) and increased reactive oxygen species (ROS) production. Transmission electron microscopy (TEM) studies revealed structurally abnormal mitochondria that were engulfed by double-membrane structures resembling autophagosomes. Consistent with mitophagy activation, fluorescence microscopy analysis showed mitochondrial Parkin recruitment and colocalization of mitochondria with autophagosome protein markers. Pharmacological or genetic inhibition of autophagy exacerbated the deleterious effects of Amitriptyline on hepatoma cells and led to increased apoptosis. These results suggest that mitophagy acts as an initial adaptive mechanism of cell survival. However persistent mitochondrial damage induced extensive and lethal mitophagy, autophagy stress and autophagolysome permeabilization leading eventually to cell death by apoptosis. Amitriptyline also induced cell death in hepatoma cells lines with mutated p53 and non-sense p53 mutation. Our results support the hypothesis that Amitriptyline-induced mitochondrial dysfunction can be a useful therapeutic strategy for HCC treatment, especially in tumors showing p53 mutations and/or resistant to genotoxic treatments.This work was supported by FIS PI13/00129 grant, Ministerio de Sanidad, Spain and Fondo Europeo de Desarrollo Regional (FEDER-Unión Europea), Proyecto de Investigación de Excelencia de la Junta de Andalucía CTS-5725, AEPMI (Asociación de Enfermos de Patología Mitocondrial) and ENACH (Asociación de Enfermedades Neurodegenerativas por Acumulación Cerebral de Hierro).Peer Reviewe

Critical role of AMP-activated protein kinase in the balance between mitophagy and mitochondrial biogenesis in MELAS disease

MELAS syndrome is a mitochondrial disorder that is caused mainly by the m.3243A > G mutation in mitochondrial DNA. Here, we report on how the severity of pathophysiological alterations is differently expressed in fibroblasts derived from patients with MELAS disease. We evaluated mitophagy activation and mitochondrial biogenesis which are the main mechanisms regulating the degradation and genesis of mitochondrial mass in MELAS fibroblasts and transmitochondrial cybrids. Our results suggest a critical balance between mitophagy and mitochondrial biogenesis which leads to the expression of different degrees of pathological severity among MELAS fibroblast cell lines according to their heteroplasmy load and the activation of AMP-activated protein kinase (AMPK). AMPK-activators such as 5-aminoimidazole-4-carboxamide 1-β-D-ribofuranoside (AICAR) or coenzyme Q10 (CoQ) increased peroxisome proliferator-activated receptor alpha (PGC-1α) nuclear translocation, mitochondrial biogenesis, antioxidant enzyme system response, autophagic flux and improved pathophysiological alterations in MELAS fibroblasts with the most severe phenotype. Our findings support the hypothesis that mitochondrial biogenesis, increased antioxidant response and autophagy clearance serve as compensatory mechanisms in response to mitophagic degradation of dysfunctional mitochondria and point out that AMPK is an important player in this balance.This work was supported by FIS PI13/00129 grant, Ministerio de Sanidad, Spain and Fondo Europeo de Desarrollo Regional (FEDER-Unión Europea), Proyecto de Investigación de Excelencia de la Junta de AndalucíaCTS-5725, and by AEPMI (Asociación de Enfermos de Patología Mitocondrial).Peer Reviewe

Treatment with the senolytics dasatinib/quercetin reduces SARS-CoV-2-related mortality in mice

The enormous societal impact of the ongoing COVID-19 pandemic has been particularly harsh for some social groups, such as the elderly. Recently, it has been suggested that senescent cells could play a central role in pathogenesis by exacerbating the pro-inflammatory immune response against SARS-CoV-2. Therefore, the selective clearance of senescent cells by senolytic drugs may be useful as a therapy to ameliorate the symptoms of COVID-19 in some cases. Using the established COVID-19 murine model K18-hACE2, we demonstrated that a combination of the senolytics dasatinib and quercetin (D/Q) significantly reduced SARS-CoV-2-related mortality, delayed its onset, and reduced the number of other clinical symptoms. The increase in senescent markers that we detected in the lungs in response to SARS-CoV-2 may be related to the post-COVID-19 sequelae described to date. These results place senescent cells as central targets for the treatment of COVID-19, and make D/Q a new and promising therapeutic too

Las relaciones internacionales de la pobreza en América Latina y el Caribe

La pobreza es uno de los grandes desafíos del Siglo XXI. Este flagelo ha sido reconocido internacionalmente por los países miembros de la Organización de las Naciones Unidas y expuesto en los Objetivos de Desarrollo del Milenio, donde figura como primera meta, reducir a la mitad, entre 1990 y 2015, la proporción de personas viviendo en pobreza extrema. Más allá de la modestia de este objetivo y los severos cuestionamientos que se han realizado sobre su medición y cumplimiento, el conjunto del sistema internacional se ha pronunciado sobre la inaceptabilidad de la pobreza y el hambre. Los principales actores formales del sistema internacional, los Estados y las organizaciones internacionales, establecieron metas e indicadores de cumplimiento para alcanzar las metas fijadas. Pocas dudas caben entonces sobre la relevancia del tema en la presente agenda de las relaciones internacionales. Sin embargo, resulta significativo que la disciplina de las Relaciones Internacionales no haya reflejado todavía la importancia del problema de la pobreza (y sus eventuales soluciones) en las corrientes predominantes del pensamiento teórico. El presente libro busca otorgar visibilidad a la problemática de la pobreza en las relaciones internacionales contemporáneas. Este es, sin duda, un objetivo ambicioso dado que el universo posible de las relaciones internacionales hoy trasciende las clásicas relaciones inter-estatales o inter-gubernamentales, para abarcar las relaciones transgubernamentales, transnacionales e intersocietales. Múltiples y complejos actores, canales y temas que cruzan distintos niveles de análisis (local, subnacional, nacional, subregional, regional, global) tornan todo un desafío la inclusión de la pobreza en un espacio central del estudio de las relaciones internacionales de los países latinoamericanos y caribeños. El conjunto de trabajos exhiben los desafíos metodológicos y teóricos que existen para definir apropiadamente y articular los niveles de análisis en los estudios sobre pobreza. Lo internacional y lo global inciden o afectan a lo local, quizás con más fuerza que la relación inversa cuando se está en presencia de relaciones de poder asimétricas (políticas y económicas) que caracterizan a la pobreza. Es por ello que resulta crucial profundizar los estudios que incluyan metodológica y teóricamente variables internacionales que explican y contribuyen a perpetuar las relaciones de pobreza (y desigualdad). Esta obra sólo pretende plantear la problemática y comenzar a andar el camino que acerque la temática de la pobreza a la disciplina de las relaciones internacionales, para así buscar soluciones a la misma en el contexto de los desafíos que ofrece esta época de cambio global.Presentación Las Relaciones Internacionales de la Pobreza Alberto D. Cimadamore 11 Parte 1 La responsabilidad jurídica internacional de los Estados y la pobreza Ana Gabriela Contreras García 31 ¿La gestión colateral? Políticas públicas de cultura y pobreza como condición cultural en Cuba Lázaro I. Rodríguez Oliva 63 Frontera, pobreza y vulnerabilidades Hernán Moreano Urigüen 101 Parte 2 La estrategia del Banco de Desarrollo de América del Norte (BDAN) en proyectos de infraestructura de impacto social en la región Sonora Arizona Liz Ileana Rodríguez Gámez 153 Agendas y actores internacionales y su incidencia en la política social. La presencia del BID y la CEPAL en la política social costarricense (1998- 2004) Lenin Mondol-López 191 Parte 3 Emigración internacional, bienestar y ciudadanía en el entorno del migrante pobre en Uruguay Diego Hernández 225 Volveré para regar el campo. Familias transnacionales y productoras del Valle Alto cochabambino Leonardo de la Torre Ávila 257 Elaboración y negociación de la pobreza indígena. Jugosas ganancias para el desarrollo capitalista en Ecuador y Colombia Jairzinho Francisco Panqueba Cifuentes 291 Parte 4 La economía de la coca: la dimensión silenciada de la dependencia Mayarí Castillo Gallardo 329 Procesos de intervención con enfoque de Cadena Productiva y su contribución a la articulación a mercados de productores de pequeña escala Diana Marcela Córdoba 36

Accesibilidad en los espacios públicos urbanizados

El libro, coordinado por el Director de ACCEPLAN, Fernando Alonso López, viene a ser un reflejo de los avances entorno a la búsqueda de accessibilidad universal en los espacios públicos urbanizados. Para aproximarse a la realidad normativa y técnica de la Orden Ministerial el libro se estructura en artículos referentes al contexto normativo, a los contenidos de la Orden, y a reflexiones y criterios en torno a la accesibilidad en la ciudad. Del conjunto de artículos, por su variedad y por su carácter multidiciplinar, se extrae un libro de referencia que ofrece la variedad de enfoques del tema y que ayuda a interpretar mejor la Orden Ministerial, su contribución a los objetivos de la Ley 51/2003 de Igualdad de Oportunidades No Discriminación y Accesibilidad Universal, LIONDAU, y su utilidad en la comformación de unas ciudades cada vez más abiertas a la diversidad funcional y a la convivencia.El llibre, coordinat pel director de ACCEPLAN, Fernando Alonso López, ve a ser un reflex dels avenços entorn de la recerca d'accessibilitat universal en els espais públics urbanitzats. Per conèixer un realitat normativa i tècnica de l'Ordre Ministerial el llibre s'estructura en articles referents al context normatiu, als continguts de l'Ordre, ja reflexions i criteris al voltant de l'accessibilitat a la ciutat. Del conjunt d'articles, per la seva varietat i pel seu caràcter multidiciplinar, s'extreu un llibre de referència que ofereix la varietat d'enfocaments del tema i que ajuda a interpretar millor l'Ordre Ministerial, la seva contribució als objectius de la Llei 51/2003 de Igualtat d'Oportunitats No Discriminació i Accessibilitat Universal, LIONDAU, i la seva utilitat en la comformación d'unes ciutats cada vegada més obertes a la diversitat funcional ia la convivència