RESUMEN
SignificanceKarrikins are chemicals in smoke that stimulate regrowth of many plants after fire. However, karrikin responses are not limited to species from fire-prone environments and can affect growth after germination. Putatively, this is because karrikins mimic an unknown signal in plants, KAI2 ligand (KL). Karrikins likely require modification in plants to become bioactive. We identify a gene, KUF1, that appears to negatively regulate biosynthesis of KL and metabolism of a specific karrikin. KUF1 expression increases in response to karrikin or KL signaling, thus forming a negative feedback loop that limits further activation of the signaling pathway. This discovery will advance understanding of how karrikins are perceived and how smoke-activated germination evolved. It will also aid identification of the elusive KL.
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Proteínas de Arabidopsis/genética , Arabidopsis/efectos de los fármacos , Arabidopsis/genética , Furanos/farmacología , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Genes de Plantas , Hidrolasas/genética , Piranos/farmacología , Arabidopsis/metabolismo , Plantones/genética , Plantones/metabolismo , Transducción de SeñalRESUMEN
Tacaribe virus (TCRV) is the prototype of New World mammarenaviruses, a group that includes several members that cause hemorrhagic fevers in humans. The TCRV genome comprises two RNA segments, named S (small) and L (large). Both genomic segments contain noncoding regions (NCRs) at their 5' and 3' ends. While the 5'- and 3'-terminal 19-nucleotide sequences are known to be essential for promoter function, the role of their neighboring internal noncoding region (iNCR) sequences remains poorly understood. To analyze the relevance of the 5' and 3' iNCRs in TCRV S RNA synthesis, mutant S-like minigenomes and miniantigenomes were generated. Using a minireplicon assay, Northern blotting, and reverse transcription-quantitative PCR, we demonstrated that the genomic 5' iNCR is specifically engaged in minigenome replication yet is not directly involved in minigenome transcription, and we showed that the S genome 3' iNCR is barely engaged in this process. Analysis of partial deletions and point mutations, as well as total or partial substitution of the 5' iNCR sequence, led us to conclude that the integrity of the whole genomic 5' iNCR is essential and that a local predicted secondary structure or RNA-RNA interactions between the 5' and 3' iNCRs are not strictly required for viral S RNA synthesis. Furthermore, we employed a TCRV reverse genetic approach to ask whether manipulation of the S genomic 5' iNCR sequence may be suitable for viral attenuation. We found that mutagenesis of the 5' promoter-proximal subregion slightly impacted recombinant TCRV virulence in vivo. IMPORTANCE The Mammarenavirus genus of the Arenaviridae family includes several members that cause severe hemorrhagic fevers associated with high morbidity and mortality rates, for which no FDA-approved vaccines and limited therapeutic resources are available. We provide evidence demonstrating the specific involvement of the TCRV S 5' noncoding sequence adjacent to the viral promoter in replication. In addition, we examined the relevance of this region in the context of an in vivo infection. Our findings provide insight into the mechanism through which this 5' viral RNA noncoding region assists the L polymerase for efficient viral S RNA synthesis. Also, these findings expand our understanding of the effect of genetic manipulation of New World mammarenavirus sequences aimed at the rational design of attenuated recombinant virus vaccine platforms.
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Arenavirus del Nuevo Mundo , Genoma Viral , Replicación de ARN , Humanos , Arenavirus del Nuevo Mundo/genética , Arenavirus del Nuevo Mundo/patogenicidad , ARN Viral/genética , Replicación de ARN/genética , Mutagénesis , Regiones Promotoras Genéticas/genéticaRESUMEN
Asteraceae (Compositae), commonly known as the sunflower family, is one of the largest plant families in the world and includes several species with pharmacological properties. In the search for new antiviral candidates, an in vitro screening against dengue virus (DENV) was performed on a series of dichloromethane and methanolic extracts prepared from six Asteraceae species, including Acmella bellidioides, Campuloclinium macrocephalum, Grindelia pulchella, Grindelia chiloensis, Helenium radiatum, and Viguiera tuberosa, along with pure phytochemicals isolated from Asteraceae: mikanolide (1), eupatoriopicrin (2), eupahakonenin B (3), minimolide (4), estafietin (5), 2-oxo-8-deoxyligustrin (6), santhemoidin C (7), euparin (8), jaceidin (9), nepetin (10), jaceosidin (11), eryodictiol (12), eupatorin (13), and 5-demethylsinensetin (14). Results showed that the dichloromethane extracts of C. macrocephalum and H. radiatum and the methanolic extracts prepared from C. macrocephalum and G. pulchella were highly active and selective against DENV-2, affording EC50 values of 0.11, 0.15, 1.80, and 3.85 µg/mL, respectively, and SIs of 171.0, 18.8, >17.36, and 64.9, respectively. From the pool of phytochemicals tested, compounds 6, 7, and 8 stand out as the most active (EC50 = 3.7, 3.1, and 6.8 µM, respectively; SI = 5.9, 6.7, and >73.4, respectively). These results demonstrate that Asteraceae species and their chemical constituents represent valuable sources of new antiviral molecules.
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Asteraceae , Sesquiterpenos , Extractos Vegetales/farmacología , Extractos Vegetales/química , Asteraceae/química , Cloruro de Metileno , Fitoquímicos/farmacología , Antivirales/farmacología , Sesquiterpenos/químicaRESUMEN
Karrikins (KARs) are chemicals in smoke that can enhance germination of many plants. Lettuce (Lactuca sativa) cv. Grand Rapids germinates in response to nanomolar karrikinolide (KAR1). Lettuce is much less responsive to KAR2 or a mixture of synthetic strigolactone analogs, rac-GR24. We investigated the molecular basis of selective and sensitive KAR1 perception in lettuce. The lettuce genome contains two copies of KARRIKIN INSENSITIVE2 (KAI2), which in Arabidopsis (Arabidopsis thaliana) encodes a receptor that is required for KAR responses. LsKAI2b is more highly expressed than LsKAI2a in dry achenes and during early stages of imbibition. Through cross-species complementation assays in Arabidopsis, we found that an LsKAI2b transgene confers robust responses to KAR1, but LsKAI2a does not. Therefore, LsKAI2b likely mediates KAR1 responses in lettuce. We compared homology models of KAI2 proteins from lettuce and a fire-follower, whispering bells (Emmenanthe penduliflora). This identified pocket residues 96, 124, 139, and 161 as candidates that influence the ligand specificity of KAI2. Further support for the importance of these residues was found through a broader comparison of pocket residues among 281 KAI2 proteins from 184 asterid species. Almost all KAI2 proteins had either Tyr or Phe identity at position 124. Genes encoding Y124-type KAI2 are more broadly distributed in asterids than in F124-type KAI2. Substitutions at residues 96, 124, 139, and 161 in Arabidopsis KAI2 produced a broad array of responses to KAR1, KAR2, and rac-GR24. This suggests that the diverse ligand preferences observed among KAI2 proteins in plants could have evolved through relatively few mutations.
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Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Furanos/metabolismo , Furanos/farmacología , Germinación/genética , Hidrolasas/genética , Lactuca/genética , Lactuca/metabolismo , Ligandos , Piranos , HumoRESUMEN
The karrikin (KAR) receptor and several related signaling components have been identified by forward genetic screening, but only a few studies have reported on upstream and downstream KAR signaling components and their roles in drought tolerance. Here, we characterized the functions of KAR UPREGULATED F-BOX 1 (KUF1) in drought tolerance using a reverse genetics approach in Arabidopsis (Arabidopsis thaliana). We observed that kuf1 mutant plants were more tolerant to drought stress than wild-type (WT) plants. To clarify the mechanisms by which KUF1 negatively regulates drought tolerance, we performed physiological, transcriptome, and morphological analyses. We found that kuf1 plants limited leaf water loss by reducing stomatal aperture and cuticular permeability. In addition, kuf1 plants showed increased sensitivity of stomatal closure, seed germination, primary root growth, and leaf senescence to abscisic acid (ABA). Genome-wide transcriptome comparisons of kuf1 and WT rosette leaves before and after dehydration showed that the differences in various drought tolerance-related traits were accompanied by differences in the expression of genes associated with stomatal closure (e.g. OPEN STOMATA 1), lipid and fatty acid metabolism (e.g. WAX ESTER SYNTHASE), and ABA responsiveness (e.g. ABA-RESPONSIVE ELEMENT 3). The kuf1 mutant plants had higher root/shoot ratios and root hair densities than WT plants, suggesting that they could absorb more water than WT plants. Together, these results demonstrate that KUF1 negatively regulates drought tolerance by modulating various physiological traits, morphological adjustments, and ABA responses and that the genetic manipulation of KUF1 in crops is a potential means of enhancing their drought tolerance.
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Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Sequías , Proteínas de Arabidopsis/metabolismo , Estomas de Plantas/fisiología , Regulación de la Expresión Génica de las Plantas , Estrés Fisiológico/genética , Ácido Abscísico/farmacología , Ácido Abscísico/metabolismo , Agua/metabolismo , Plantas Modificadas Genéticamente/metabolismoRESUMEN
Resveratrol (RES) is a polyphenol with increasing interest for its inhibitory effects on a wide variety of viruses. Zika virus (ZIKV) is an arbovirus which causes a broad spectrum of ophthalmological manifestations in humans. Currently there is no certified therapy or vaccine to treat it, thus it has become a major global health threat. Retinal pigment epithelium (RPE) is highly permissive and susceptible to ZIKV. This work explored the protective effects of RES on ZIKV-infected human RPE cells. RES treatment resulted in a significant reduction of infectious viral particles in infected male ARPE-19 and female hTERT-RPE1 cells. This protection was positively influenced by the action of RES on mitochondrial dynamics. Also, docking studies predicted that RES has a high affinity for two enzymes of the rate-limiting steps of pyrimidine and purine biosynthesis and viral polymerase. This evidence suggests that RES might be a potential antiviral agent to treat ZIKV-induced ocular abnormalities.
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Antivirales/farmacología , Resveratrol/farmacología , Epitelio Pigmentado de la Retina/efectos de los fármacos , Epitelio Pigmentado de la Retina/virología , Virus Zika/efectos de los fármacos , Antivirales/química , Sitios de Unión , Línea Celular , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Desarrollo de Medicamentos , Células Epiteliales/efectos de los fármacos , Células Epiteliales/virología , Humanos , Ligandos , Dinámicas Mitocondriales/efectos de los fármacos , Modelos Biológicos , Modelos Moleculares , Unión Proteica , Resveratrol/química , Relación Estructura-Actividad , Replicación Viral/efectos de los fármacos , Infección por el Virus Zika/tratamiento farmacológico , Infección por el Virus Zika/patología , Infección por el Virus Zika/virologíaRESUMEN
BACKGROUND: Ecological speciation is a prominent mechanism of diversification but in many evolutionary radiations, particularly in invertebrates, it remains unclear whether supposedly critical ecological traits drove or facilitated diversification. As a result, we lack accurate knowledge on the drivers of diversification for most evolutionary radiations along the tree of life. Freshwater mollusks present an enigmatic example: Putatively adaptive radiations are being described in various families, typically from long-lived lakes, whereas other taxa represent celebrated model systems in the study of ecophenotypic plasticity. Here we examine determinants of shell-shape variation in three nominal species of an ongoing ampullariid radiation in the Malawi Basin (Lanistes nyassanus, L. solidus and Lanistes sp. (ovum-like)) with a common garden experiment and semi-landmark morphometrics. RESULTS: We found significant differences in survival and fecundity among these species in contrasting habitats. Morphological differences observed in the wild persisted in our experiments for L. nyassanus versus L. solidus and L. sp. (ovum-like), but differences between L. solidus and L. sp. (ovum-like) disappeared and re-emerged in the F1 and F2 generations, respectively. These results indicate that plasticity occurred, but that it is not solely responsible for the observed differences. Our experiments provide the first unambiguous evidence for genetic divergence in shell morphology in an ongoing freshwater gastropod radiation in association with marked fitness differences among species under controlled habitat conditions. CONCLUSIONS: Our results indicate that differences in shell morphology among Lanistes species occupying different habitats have an adaptive value. These results also facilitate an accurate reinterpretation of morphological variation in fossil Lanistes radiations, and thus macroevolutionary dynamics. Finally, our work testifies that the shells of freshwater gastropods may retain signatures of adaptation at low taxonomic levels, beyond representing an evolutionary novelty responsible for much of the diversity and disparity in mollusks altogether.
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Exoesqueleto/anatomía & histología , Fósiles , Caracoles/anatomía & histología , Caracoles/genética , Animales , Evolución Biológica , Ecosistema , Especiación Genética , Lagos , Malaui , Modelos Biológicos , Filogenia , Caracoles/clasificaciónRESUMEN
Invertebrates are exceptionally diverse, but many are in decline because of anthropogenic changes to their habitat. This situation is particularly problematic for taxa that are not well monitored or taxonomically poorly understood, because the lack of knowledge hampers conservation. Despite their important functional role in freshwater ecosystems, African bivalves of the family Unionidae remain poorly studied compared to their highly threatened relatives in Europe, the U.S.A. and Canada. To resolve relationships and to study diversification dynamics in space and time, we performed time-calibrated phylogenetic studies and biogeographical modeling on the unionids from the East African Rift System and surroundings, including representatives of all currently recognized Afrotropical genera except for Brazzaea (and Unio from southern Africa). Our analyses indicate that all sampled Afrotropical unionids belong to the tribe Coelaturini (subfamily Parreysiinae), as does the genus Moncetia from Lake Tanganyika, which is currently attributed to the family Iridinidae. Colonization of Africa from Eurasia by Parreysiinae occurred ~17 Ma ago, and the subsequent diversification of Coelaturini in Africa continued at a steady pace, although net diversification decreased over time as more niches and ecoregions became occupied. Clades in Coelaturini largely reflect drainage basins, with the oldest lineages and highest regional diversity occurring in Lake Tanganyika, followed by the Congo Basin watershed in general. The species assemblage of Lake Tanganyika reflects multiple independent events of colonization and intralacustrine diversification since the Late Miocene or Early Pliocene. The clades of other regions, including that containing the species from Lake Malawi, are comparatively young. Biogeographical analyses indicate that the colonization history was mainly driven by cladogenesis in sympatry, whereas few anagenetic events contributed to the modern distribution of Coelaturini. Ancestral range estimations demonstrate that Coelaturini originated in the Victoria and/or Tanganyika ecoregions, and that the Congo Basin played an essential role in the colonization of Africa by Coelaturini.
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Biodiversidad , Ecosistema , Agua Dulce , Unionidae/fisiología , África Oriental , Animales , Teorema de Bayes , Calibración , Fósiles , Lagos , Filogenia , Filogeografía , Especificidad de la EspecieRESUMEN
In this study, we determined the effect of drying on extraction kinetics, yield, and lutein content and recovery of the microalga Muriellopsis sp. (MCH35) using the supercritical fluid extraction (SFE) process. The strain was cultivated in an open-raceways reactor in the presence of seawater culture media and arid outdoor conditions in the north of Chile. Spray-drying (SD) and freeze-drying (FD) techniques were used for dehydrating the microalgal biomass. Extraction experiments were performed by using Box-Behnken designs, and the parameters were studied: pressure (30-50 MPa), temperature (40-70 °C), and co-solvent (0-30% ethanol), with a CO2 flow rate of 3.62 g/min for 60 min. Spline linear model was applied in the central point of the experimental design to obtain an overall extraction curve and to reveal extraction kinetics involved in the SFE process. A significant increase in all variables was observed when the level of ethanol (15-30% v/v) was increased. However, temperature and pressure were non-significant parameters in the SFE process. The FD method showed an increase in lutein content and recovery by 0.3-2.5-fold more than the SD method. Overall, Muriellopsis sp. (MCH35) is a potential candidate for cost-effective lutein production, especially in desert areas and for different biotechnological applications.
Asunto(s)
Luteína/química , Microalgas , Agua/química , Chile , Cromatografía con Fluido SupercríticoRESUMEN
In this work, several ribavirin analogues were synthesized and incorporated into a multivalent arrangement. Both were subsequently modified by the addition of polyhydroxylated residues. Their antiviral activity was tested against Junín virus, etiological agent responsible of Argentine hemorrhagic fever. Some compounds inhibited Junín virus in the range of 13.2-389.1⯵M. Two modified ribavirin analogues presented an effective concentration comparable to ribavirin but with a higher selectivity index.
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Antivirales/farmacología , Virus Junin/efectos de los fármacos , Ribavirina/análogos & derivados , Células A549 , Animales , Chlorocebus aethiops , Humanos , Células VeroRESUMEN
Natural regeneration of abandoned farmland provides an important opportunity to contribute to global reforestation targets, including the Bonn Challenge. Of particular importance are the montane tropics, where a long history of farming, frequently on marginal soils, has rendered many ecosystems highly degraded and hotspots of extinction risk. Ants play crucial roles in ecosystem functioning, and a key question is how time since abandonment and elevation (and inherent temperature gradients therein) affect patterns of ant recovery within secondary forest systems. Focusing on the Colombian Andes across a 1300 m altitudinal gradient and secondary forest (2-30 years) recovering on abandoned cattle pastures, we find that over time ant community composition and species richness recovered towards that of primary forest. However, these relationships are strongly dependent on elevation with the more open and warmer pasturelands supporting more ants than either primary or secondary forest at a particular elevation. The loss of species richness and change in species composition with elevation is less severe in pasture than forests, suggesting that conditions within pasture and its remaining scattered trees, hedgerows and forest fragments, are more favourable for some species, which are likely in or near thermal debt. Promoting and protecting natural regenerating forests over the long term in the montane tropics will likely offer significant potential for returning ant communities towards primary forest levels.
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Hormigas , Agricultura , Animales , Bovinos , Ecosistema , Bosques , ÁrbolesRESUMEN
The aim of this study was to investigate the effect of A771726, the active metabolite of leflunomide, (CONICET-UBA), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad against the infection with Junín virus (JUNV), agent of Argentine hemorrhagic fever (AHF). The treatment with non-cytotoxic concentrations of A771726 of Vero and A549 cells infected with JUNV inhibited virus replication in a dose-dependent manner, as determined by virus yield reduction assay. The antiviral effectiveness of A771726 was not importantly affected by the multiplicity of infection and the virus strain. Moreover, the combination of A771726 and ribavirin had a significantly more potent antiviral activity than each single drug treatment. Mechanistic studies showed that the main action of A771726 is exerted before 6 h of JUNV infection. Accordingly, inhibition of viral RNA synthesis was detected in treated infected cells by real time RT-PCR. The exogenous addition of uridine or orotic acid produced a partial reversal of the inhibitory effect of A771726 on infective virus production whereas a total reversion was detected on JUNV RNA synthesis, probably by restoration of the enzymatic activity of dihydroorotate dehydrogenase (DHODH) and the intracellular pyrimidine pools. In conclusion, these results suggest that the antiviral target would be viral RNA synthesis through pyrimidine depletion, but any other effect of the compound on JUNV infection cannot be excluded. This study opens the possibility of the therapeutic application of a wide spectrum host-targeted compound alone or in combination with ribavirin to combat AHF as well as other human pathogenic arenaviruses.
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Compuestos de Anilina/farmacología , Antivirales/farmacología , Hidroxibutiratos/farmacología , Virus Junin/efectos de los fármacos , Replicación Viral/efectos de los fármacos , Células A549 , Animales , Chlorocebus aethiops , Crotonatos , Relación Dosis-Respuesta a Droga , Sinergismo Farmacológico , Humanos , Nitrilos , ARN Viral/biosíntesis , Ribavirina/farmacología , Toluidinas , Células Vero , Carga ViralRESUMEN
In industrial-scale microalgal cultures, non-target microalgae compete with the desired species for nutrients and CO2, thus reducing the growth rate of the target species and the quality of the produced biomass. Microalgae identification is generally considered a complicated issue; although, in the last few years, new molecular methods have helped to rectify this problem. Among the different techniques available, DNA barcoding has proven very useful in providing rapid, accurate, and automatable species identification; in this work, it is used to assess the genomic identity of the microalga species Scenedesmus sp. 'almeriensis', a common strain in industrial-scale cultures. Barcode markers rbcL and ITS1-5.8S-ITS2 were sequenced and the obtained genomic information was used to design a quantitative PCR assay to precisely quantify the S. almeriensis concentration in microalgal cultures of industrial interest. TaqMan chemistry was used to quantify down to 1 µg/L dry weight of S. almeriensis cells, including in the presence of concentrated mixed cultures of other microalgae. A simple direct qPCR approach was also investigated to avoid classic DNA extraction and to reduce total assay time to approximately 2 h. The objective was to design strain-specific tools able to confirm and quantify the presence of different strains in whatever microalgae culture so as to achieve maximal productivity and quality of the produced biomass.
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Microalgas/crecimiento & desarrollo , Biomasa , Código de Barras del ADN Taxonómico/métodos , Industrias/métodos , Microalgas/genética , Scenedesmus/genética , Scenedesmus/crecimiento & desarrolloRESUMEN
We have recently demonstrated that AR-12 (OSU-03012) reduces the function and ATPase activities of multiple HSP90 and HSP70 family chaperones. Combined knock down of chaperones or AR-12 treatment acted to reduce the expression of virus receptors and essential glucosidase proteins. Combined knock down of chaperones or AR-12 treatment inactivated mTOR and elevated ATG13 S318 phosphorylation concomitant with inducing an endoplasmic reticulum stress response that in an eIF2α-dependent fashion increased Beclin1 and LC3 expression and autophagosome formation. Over-expression of chaperones prevented the reduction in receptor/glucosidase expression, mTOR inactivation, the ER stress response, and autophagosome formation. AR-12 reduced the reproduction of viruses including Mumps, Influenza, Measles, Junín, Rubella, HIV (wild type and protease resistant), and Ebola, an effect replicated by knock down of multiple chaperone proteins. AR-12-stimulated the co-localization of Influenza, EBV and HIV virus proteins with LC3 in autophagosomes and reduced viral protein association with the chaperones HSP90, HSP70, and GRP78. Knock down of Beclin1 suppressed drug-induced autophagosome formation and reduced the anti-viral protection afforded by AR-12. In an animal model of hemorrhagic fever virus, a transient exposure of animals to low doses of AR-12 doubled animal survival from â¼30% to â¼60% and suppressed liver damage as measured by ATL, GGT and LDH release. Thus through inhibition of chaperone protein functions; reducing the production, stability and processing of viral proteins; and stimulating autophagosome formation/viral protein degradation, AR-12 acts as a broad-specificity anti-viral drug in vitro and in vivo. We argue future patient studies with AR-12 are warranted. J. Cell. Physiol. 231: 2286-2302, 2016. © 2016 Wiley Periodicals, Inc.
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Autofagosomas/efectos de los fármacos , Autofagia/efectos de los fármacos , Chaperonas Moleculares/metabolismo , Pirazoles/farmacología , Sulfonamidas/farmacología , Replicación Viral/efectos de los fármacos , Línea Celular , Retículo Endoplásmico/efectos de los fármacos , Retículo Endoplásmico/metabolismo , Chaperón BiP del Retículo Endoplásmico , Estrés del Retículo Endoplásmico/efectos de los fármacos , Estrés del Retículo Endoplásmico/fisiología , Humanos , Replicación Viral/fisiologíaRESUMEN
Twelve polyhydroxylated sulfated steroids synthesized from a 5α-cholestane skeleton with different substitutions in C-2, C-3 and C-6 were evaluated for cytotoxicity and antiviral activity against herpes simplex virus (HSV) by a virus plaque reduction assay. Four compounds elicited a selective inhibitory effect against HSV. The disodium salt of 2ß,3α-dihydroxy-6E-hydroximine-5α-cholestane-2,3-disulfate, named compound 7, was the most effective inhibitor of HSV-1, HSV-2 and pseudorabies virus (PrV) strains, including acyclovir-resistant variants, in human and monkey cell lines. Preliminary mechanistic studies demonstrated that compound 7 did not affect the initial steps of virus entry but inhibited a subsequent event in the infection process of HSV.
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Antivirales/farmacología , Colestanos/farmacología , Herpesvirus Humano 1/efectos de los fármacos , Herpesvirus Humano 2/efectos de los fármacos , Esteroides/farmacología , Animales , Antivirales/química , Línea Celular , Colestanos/química , Herpes Genital/virología , Herpes Simple/virología , Herpesvirus Humano 1/fisiología , Herpesvirus Humano 2/fisiología , Humanos , Estructura Molecular , Esteroides/química , Relación Estructura-Actividad , Internalización del Virus/efectos de los fármacosRESUMEN
Secondary acute myeloid leukemia is a very rare complication in patients with solid organ transplantation. We report a 62 years old female who received a right single lung allograft for idiopathic pulmonary fibrosis. Her immunosuppression scheme consisted in prednisone, azathioprine, and tacrolimus. Two years after the transplantation, she presented with progressive pancytopenia. Bone marrow aspiration was informed as a M4 acute myeloid leukemia, confirmed by flow cytometry. Cytogenetic study was complex, including alterations in chromosome 5. A secondary acute myeloid leukemia was diagnosed. The patient developed nosocomial pneumonia and died a few days after the diagnosis, without specific treatment. The pathogenesis of acute myeloid leukemia is probably related to the intensive exposure to immunosuppressant, especially azathioprine, in these patients.
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Inmunosupresores/efectos adversos , Leucemia Mieloide Aguda/etiología , Trasplante de Pulmón/efectos adversos , Azatioprina/efectos adversos , Médula Ósea/patología , Cromosomas Humanos Par 5 , Resultado Fatal , Femenino , Humanos , Leucopenia/complicaciones , Persona de Mediana Edad , Pancitopenia/complicaciones , Tacrolimus/efectos adversosRESUMEN
The interactions between bovine serum albumin (BSA) and mycophenolic acid (MPA) were investigated in silico through molecular docking and in vitro, using fluorescence spectroscopy. Dynamic light scattering and scanning electron microscopy were used to figure out the structure of MPA-Complex (MPA-C). The binding affinity between MPA and BSA was determined, yielding a Kd value of (12.0 ± 0.7) µM, and establishing a distance of 17 Å between the BSA and MPA molecules. The presence of MPA prompted protein aggregation, leading to the formation of MPA-C. The cytotoxicity of MPA-C and its ability to fight Junín virus (JUNV) were tested in A549 and Vero cell lines. It was found that treating infected cells with MPA-C decreased the JUNV yield and was more effective than free MPA in both cell line models for prolonged time treatments. Our results represent the first report of the antiviral activity of this type of BSA-MPA complex against JUNV, as assessed in cell culture model systems. MPA-C shows promise as a candidate for drug formulation against human pathogenic arenaviruses.
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Virus Junin , Albúmina Sérica Bovina , Humanos , Ácido Micofenólico , Simulación del Acoplamiento Molecular , Replicación Viral , Antivirales/farmacologíaRESUMEN
OBJECTIVE: To present paleopathological evidence of a congenital anomaly with photographic support and a review that will help scholars to diagnose the condition. MATERIALS: Well-preserved skeletal remains of a child from central Colombia, dated 968-1046 CE. METHODS: Macroscopic examination and computerized axial tomography. RESULTS: Two holes were observed in the skull. CONCLUSIONS: The pathology is consistent with a neural tube defect or an inclusion cyst. SIGNIFICANCE: Neural tube defects and inclusion cysts, in paleopathology, are rarely reported in children. The preservation and origin of the individual make this case valuable. The photographic support and the review is useful for other scholars in the field. LIMITATIONS: It was not possible to determine a single cause. SUGGESTIONS FOR FUTURE RESEARCH: Review cases in identified osteological collections.
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Paleopatología , Cráneo , Humanos , Niño , Diagnóstico Diferencial , Cráneo/diagnóstico por imagen , Paleopatología/métodos , América del Sur , CabezaRESUMEN
There is no specific chemotherapy approved for the treatment of pathogenic arenaviruses that cause severe hemorrhagic fever (HF) in the population of endemic regions in America and Africa. The present study reports the effects of the natural flavonoid quercetin (QUER) on the infection of A549 and Vero cells with Junín virus (JUNV), agent of the Argentine HF. By infectivity assays, a very effective dose-dependent reduction of JUNV multiplication was shown by cell pretreatment at 2-6 h prior to the infection at non-cytotoxic concentrations, with 50% effective concentration values in the range of 6.1-7.5 µg/mL. QUER was also active by post-infection treatment but with minor efficacy. Mechanistic studies indicated that QUER mainly affected the early steps of virus adsorption and internalization in the multiplication cycle of JUNV. Treatment with QUER blocked the phosphorylation of Akt without changes in the total protein expression, detected by Western blot, and the consequent perturbation of the PI3K/Akt pathway was also associated with the fluorescence redistribution from membrane to cytoplasm of TfR1, the cell receptor recognized by JUNV. Then, it appears that the cellular antiviral state, induced by QUER treatment, leads to the prevention of JUNV entry into the cell.
Asunto(s)
Infecciones por Arenaviridae , Arenavirus , Chlorocebus aethiops , Animales , Quercetina/farmacología , Flavonoides , Fosfatidilinositol 3-Quinasas , Proteínas Proto-Oncogénicas c-akt , Células VeroRESUMEN
Despite the increasing accessibility of high-throughput sequencing, obtaining high-quality genomic data on non-model organisms without proximate well-assembled and annotated genomes remains challenging. Here, we describe a workflow that takes advantage of distant genomic resources and ingroup transcriptomes to select and jointly enrich long open reading frames (ORFs) and ultraconserved elements (UCEs) from genomic samples for integrative studies of microevolutionary and macroevolutionary dynamics. This workflow is applied to samples of the African unionid bivalve tribe Coelaturini (Parreysiinae) at basin and continent-wide scales. Our results indicate that ORFs are efficiently captured without prior identification of intron-exon boundaries. The enrichment of UCEs was less successful, but nevertheless produced substantial data sets. Exploratory continent-wide phylogenetic analyses with ORF supercontigs (>515,000 parsimony informative sites) resulted in a fully resolved phylogeny, the backbone of which was also retrieved with UCEs (>11,000 informative sites). Variant calling on ORFs and UCEs of Coelaturini from the Malawi Basin produced ~2000 SNPs per population pair. Estimates of nucleotide diversity and population differentiation were similar for ORFs and UCEs. They were low compared to previous estimates in molluscs, but comparable to those in recently diversifying Malawi cichlids and other taxa at an early stage of speciation. Skimming off-target sequence data from the same enriched libraries of Coelaturini from the Malawi Basin, we reconstructed the maternally-inherited mitogenome, which displays the gene order inferred for the most recent common ancestor of Unionidae. Overall, our workflow and results provide exciting perspectives for integrative genomic studies of microevolutionary and macroevolutionary dynamics in non-model organisms.