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1.
Front Immunol ; 15: 1342816, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38515753

RESUMO

Salmonid alphavirus (SAV) causes pancreas disease (PD), which negatively impacts farmed Atlantic salmon. In this study, fish were vaccinated with a DNA-PD vaccine (DNA-PD) and an oil-adjuvanted, inactivated whole virus PD vaccine (Oil-PD). Controls were two non-PD vaccinated groups. Fish were kept in one tank and challenged by cohabitation with SAV genotype 2 in seawater. Protection against infection and mortality was assessed for 84 days (Efficacy study). Nineteen days post challenge (dpc), subgroups of fish from all treatment groups were transferred to separate tanks and cohabited with naïve fish (Transmission study 1) or fish vaccinated with a homologous vaccine (Transmission study 2), to evaluate virus transmission for 26 days (47 dpc). Viremia, heart RT-qPCR and histopathological scoring of key organs affected by PD were used to measure infection levels. RT-droplet digital PCR quantified shedding of SAV into water for transmission studies. The Efficacy study showed that PD associated growth-loss was significantly lower and clearance of SAV2 RNA significantly higher in the PD-DNA group compared to the other groups. The PD-DNA group had milder lesions in the heart and muscle. Cumulative mortality post challenge was low and not different between groups, but the DNA-PD group had delayed time-to-death. In Transmission study 1, the lowest water levels of SAV RNA were measured in the tanks containing the DNA-PD group at 21 and 34 dpc. Despite this, and irrespective of the treatment group, SAV2 was effectively transmitted to the naïve fish during 26-day cohabitation. At 47 dpc, the SAV RNA concentrations in the water were lower in all tanks compared to 34 dpc. In Transmission study 2, none of the DNA-PD immunized cohabitants residing with DNA-PD-vaccinated, pre-challenged fish got infected. In contrast, Oil-PD immunized cohabitants residing with Oil-PD-vaccinated, pre-challenged fish, showed infection levels similar to the naïve cohabitants in Transmission study 1. The results demonstrate that the DNA-PD vaccine may curb the spread of SAV infection as the DNA-PD vaccinated, SAV2 exposed fish, did not spread the infection to cohabiting DNA-PD vaccinated fish. This signifies that herd immunity may be achieved by the DNA-PD vaccine, a valuable tool to control the PD epizootic in farmed Atlantic salmon.


Assuntos
Alphavirus , Doenças dos Peixes , Pancreatopatias , Salmo salar , Vacinas de DNA , Vacinas Virais , Animais , Pancreatopatias/veterinária , Pancreatopatias/patologia , RNA/genética , Água , Pâncreas/patologia , DNA , Genótipo
2.
3.
Npj Ment Health Res ; 2(1): 17, 2023 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-38609516

RESUMO

Over the past few years, the COVID-19 pandemic has exerted various impacts on the world, notably concerning mental health. Nevertheless, the precise influence of psychosocial stressors on this mental health crisis remains largely unexplored. In this study, we employ natural language processing to examine chat text from a mental health helpline. The data was obtained from a chat helpline called Safe Hour from the "It Gets Better" project in Chile. This dataset encompass 10,986 conversations between trained professional volunteers from the foundation and platform users from 2018 to 2020. Our analysis shows a significant increase in conversations covering issues of self-image and interpersonal relations, as well as a decrease in performance themes. Also, we observe that conversations involving themes like self-image and emotional crisis played a role in explaining both suicidal behavior and depressive symptoms. However, anxious symptoms can only be explained by emotional crisis themes. These findings shed light on the intricate connections between psychosocial stressors and various mental health aspects in the context of the COVID-19 pandemic.

4.
Front Microbiol ; 13: 1068328, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36519174

RESUMO

Infectious Bursal Disease Virus (IBDV) is the causative agent of an immunosuppressive disease that affects domestic chickens (Gallus gallus) severely affecting poultry industry worldwide. IBDV infection is characterized by a rapid depletion of the bursal B cell population by apoptosis and the atrophy of this chief lymphoid organ. Previous results from our laboratory have shown that exposure of infected cells to type I IFN leads to an exacerbated apoptosis, indicating an important role of IFN in IBDV pathogenesis. It has been described that recognition of the dsRNA IBDV genome by MDA5, the only known cytoplasmic pattern recognition receptor for viral RNA in chickens, leads to type I IFN production. Here, we confirm that TRIM25, an E3 ubiquitin ligase that leads to RIG-I activation in mammalian cells, significantly contributes to positively regulate MDA5-mediated activation of the IFN-inducing pathway in chicken DF-1 cells. Ectopic expression of chTRIM25 together with chMDA5 or a deletion mutant version exclusively harboring the CARD domains (chMDA5 2CARD) enhances IFN-ß and NF-ĸB promoter activation. Using co-immunoprecipitation assays, we show that chMDA5 interacts with chTRIM25 through the CARD domains. Moreover, chTRIM25 co-localizes with both chMDA5 and chMDA5 2CARD, but not with chMDA5 mutant proteins partially or totally lacking these domains. On the other hand, ablation of endogenous chTRIM25 expression reduces chMDA5-induced IFN-ß and NF-ĸB promoter activation. Interestingly, ectopic expression of either wild-type chTRIM25, or a mutant version (chTRIM25 C59S/C62S) lacking the E3 ubiquitin ligase activity, restores the co-stimulatory effect of chMDA5 in chTRIM25 knockout cells, suggesting that the E3-ubiquitin ligase activity of chTRIM25 is not required for its downstream IFN-ß and NF-ĸB activating function. Also, IBDV-induced expression of IFN-ß, Mx and OAS genes was reduced in chTRIM25 knockout as compared to wild-type cells, hence contributing to the enhancement of IBDV replication. Enhanced permissiveness to replication of other viruses, such as avian reovirus, Newcastle disease virus and vesicular stomatitis virus was also observed in chTRIM25 knockout cells. Additionally, chTRIM25 knockout also results in reduced MAVS-induced IFN-ß promoter stimulation. Nonetheless, similarly to its mammalian counterpart, chTRIM25 overexpression in wild-type DF-1 cells causes the degradation of ectopically expressed chMAVS.

5.
Exp Gerontol ; 169: 111954, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36122595

RESUMO

INTRODUCTION: Vitamin D - concretely its active form 1,25-dihydroxyvitamin D (1,25(OH)2D) - maintains several physiological processes. Oxylipins are oxidized lipids derived from ω-6 and ω-3 polyunsaturated fatty acids involved in inflammation. Little is known about the association of 1,25(OH)2D with inflammatory parameters in middle-aged populations - who could be at risk of vitamin D deficiency -. The aim of this study was to investigate the relationship between 1,25(OH)2D plasma levels with circulating white blood cells, platelets counts and oxylipins levels. MATERIALS AND METHODS: A total of 74 (53 % women) middle-aged (40-65 years old) adults were recruited for this cross-sectional study. 1,25(OH)2D plasma levels were measured using an immunochemiluminometric assay. White blood cells and platelets were analyzed by hemocytometry. ω-6 and ω-3 oxylipins plasma levels were measured using liquid chromatography - tandem mass spectrometry. Simple and multiple linear regression models, and Pearson correlation analyses, were performed to study the association of 1,25(OH)2D levels with WBC and platelets counts, and oxylipins, respectively. RESULTS: 1,25(OH)2D plasma levels were positively related with linoleic acid-derived oxylipins and isoprostanes plasma levels, whereas an inverse relationship with dihomo-γ-linolenic acid/linoleic acid and arachidonic acid/linoleic acid ratios was unveiled. No significant associations were observed for circulating ω-3 oxylipins, white blood cells levels or platelets count. CONCLUSIONS: Linoleic acid-derived oxylipins and isoprostanes plasma levels may be influenced by 1,25(OH)2D plasma levels. Further investigations are needed to elucidate the impact of other vitamin D forms upon circulating oxylipins levels.


Assuntos
Ácidos Graxos Ômega-3 , Oxilipinas , Humanos , Feminino , Pessoa de Meia-Idade , Idoso , Masculino , Ácido Linoleico , Isoprostanos , Estudos Transversais , Vitamina D
6.
Water Res ; 218: 118487, 2022 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-35504160

RESUMO

During the Millennium Drought in southeast Australia (2001-2009), dryland wetlands experienced widespread ecological deterioration, which highlighted their vulnerability to natural climate variability and the potential effects of drying climate change. Here we use 30-year observed streamflow data (1991-2020) and numerical models to assess the impacts of climate variability and climate change on the Macquarie Marshes (the Marshes), a large floodplain wetland complex in the semi-arid region of New South Wales, Australia. A fast ecohydrologic emulator based on network linear programming with side constraints was developed to simulate the spatial and temporal responses of different wetland vegetation types to water regime. The emulator represents the wetland by a series of inter-connected level-pool reservoirs with the volume-discharge relationship obtained from a calibrated quasi-2d hydrodynamic model. The emulator reproduces daily flows and volume with good accuracy (Nash-Sutcliffe statistic ranging from 0.61 to 0.96) with 1/26,000 of the computational effort. We use the emulator to simulate the potential effects of climatic variability on vegetation by running the model over 30 years of observed data and 1000 statistically representative 30-year streamflow time series, which were generated using a stochastic model calibrated to the gauged flows. The collection of results for all 1000 contemporary simulations indicates the Marshes experience severe conditions 43% (± 18%) of the time in a 30-year period. We then ran an additional 6000 simulations to assess the combined impacts of climate variability and future climate change at the end of the century. For the driest future climates (-60% and -30% reduction in runoff), the Marshes remain in severe condition 89% (± 6%) and 63% (± 16%) of the time, respectively, while no major differences with respect to the contemporary conditions were found for the wetter future. Our results highlight the importance of quantifying the extent and uncertainty in the degradation of these ecosystems due to climate variability and change for informing management decisions.


Assuntos
Ecossistema , Áreas Alagadas , Austrália , Mudança Climática , Secas
7.
Am J Public Health ; 112(2): 223-226, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35080940

RESUMO

We present a record of events that led to the creation of the Puerto Rico Case Investigation and Contact-Tracing System (CICTS) to monitor and control the spread of severe acute respiratory syndrome coronavirus 2 in Puerto Rico. The development of the CICTS is a significant step toward establishing a comprehensive infectious disease surveillance system in Puerto Rico. Furthering the development of a CICTS infrastructure is critical in the response against future emerging infectious diseases in the region. (Am J Public Health. 2022;112(2):223-226. https://doi.org/10.2105/AJPH.2021.306584).


Assuntos
COVID-19/epidemiologia , COVID-19/prevenção & controle , Busca de Comunicante/métodos , Vigilância da População/métodos , Feminino , Humanos , Masculino , Porto Rico/epidemiologia , SARS-CoV-2
8.
Ann Vasc Surg ; 84: 218-224, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34995742

RESUMO

OBJECTIVE: Epidemiological data on aneurysmal disease affecting the abdominal aorta in Latin American countries are limited. In our institution, the National Institute of Medical Sciences and Nutrition Salvador Zubiran (INCMNSZ), we have reported an Abdominal Aortic Aneurysm (AAA) prevalence of 3.26% in patients at risk from our Ultrasound (US) screening program. We aim to determine and compare the prevalence of undetected AAA in four different Metropolitan areas in Mexico to justify further US screening efforts. METHODS: A cross-sectional multicenter study was conducted in 9 different academic institutions. Abdominal Computed Tomographies (CT) from patients with age equal or greater than 55 years in our center (INCMNSZ), and in 65 year old patients and older in the remainder institutions were systematically reviewed. Abdominal aortic diameters were measured at the level of the superior (SMA) and inferior mesenteric arteries (IMA) in nonaneurysmal aortas and maximum diameters in the found AAA. Categorical data were analyzed by nonparametric statistic test at significance level (P < 0.05), the Pearson test was used to determine the correlation of age and aortic diameters. RESULTS: The cohort included a total of 12, 936 patients paired with respect gender (53% females, with a mean age of 69 years), the AAA prevalence found in the studied Mexican population was 3.08% (399 AAA patients). In centers where more than 200 CTs scans were reviewed, the prevalence was 4.03%, compared to the 4.63% found in centers with less than 200 studies (P = 0.41). In patients between the ages of 55 to 64 from INCMNSZ (3889 total), the prevalence was 0.77%, supporting the need of focused US-screening programs in individuals at the age of 65 and older in our country. CONCLUSIONS: The introduction of a national US Screening Program for the detection of AAA in Mexico represents a challenge in our current health system. This Multicenter initiative demonstrates that our AAA prevalence is not different to other international reports; imaging screening might represent cost-effective strategy for reduction of aneurysm-related mortality.


Assuntos
Aneurisma da Aorta Abdominal , Idoso , Aneurisma da Aorta Abdominal/diagnóstico por imagem , Aneurisma da Aorta Abdominal/epidemiologia , Estudos Transversais , Feminino , Humanos , Masculino , Programas de Rastreamento/métodos , México/epidemiologia , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , Resultado do Tratamento , Ultrassonografia
9.
Angew Chem Int Ed Engl ; 61(1): e202112288, 2022 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-34739741

RESUMO

A palladium-catalyzed strategy is presented to synthesize unsymmetrically linked heterocycles within stereoselective tetrasubstituted olefins. This reaction is proposed to occur via a vinyl-PdII intermediate capable of initiating the cyclization of various alkyne-tethered nucleophiles. Products are formed in up to 96 % yield and excellent stereoselectivities are obtained using low catalyst loadings. This transformation was scalable up to 1 mmol and mechanistic studies suggest a syn-carbopalladation of the carbamoyl chloride followed by PdII -catalyzed cyclization of alkyne-tethered nucleophiles.

10.
Cells ; 10(12)2021 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-34943787

RESUMO

Dendritic cells (DCs) are the most potent antigen-presenting cells, and their function is essential to configure adaptative immunity and avoid excessive inflammation. DCs are predicted to play a crucial role in the clinical evolution of the infection by the severe acute respiratory syndrome (SARS) coronavirus (CoV)-2. DCs interaction with the SARS-CoV-2 Spike protein, which mediates cell receptor binding and subsequent fusion of the viral particle with host cell, is a key step to induce effective immunity against this virus and in the S protein-based vaccination protocols. Here we evaluated human DCs in response to SARS-CoV-2 S protein, or to a fragment encompassing the receptor binding domain (RBD) challenge. Both proteins increased the expression of maturation markers, including MHC molecules and costimulatory receptors. DCs interaction with the SARS-CoV-2 S protein promotes activation of key signaling molecules involved in inflammation, including MAPK, AKT, STAT1, and NFκB, which correlates with the expression and secretion of distinctive proinflammatory cytokines. Differences in the expression of ACE2 along the differentiation of human monocytes to mature DCs and inter-donor were found. Our results show that SARS-CoV-2 S protein promotes inflammatory response and provides molecular links between individual variations and the degree of response against this virus.


Assuntos
Células Dendríticas/patologia , Células Dendríticas/virologia , Receptores Virais/metabolismo , SARS-CoV-2/metabolismo , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/metabolismo , Enzima de Conversão de Angiotensina 2/metabolismo , Moléculas de Adesão Celular/metabolismo , Diferenciação Celular , Citocinas/biossíntese , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Humanos , Inflamação/patologia , Lectinas Tipo C/metabolismo , Domínios Proteicos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptores de Superfície Celular/metabolismo , Fatores de Transcrição STAT/metabolismo , Transdução de Sinais , Doadores de Tecidos
11.
Org Lett ; 23(19): 7540-7544, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34541848

RESUMO

The reaction of alkene-tethered trifluoroacetimidoyl chlorides with trialkyl phosphites furnishes 1-amino-2,2,2-trifluoroalkylphosphonates. The products were generated in moderate to good yields, and the scalability of this process was showcased. Partial hydrolysis of the phosphonate moiety was achieved. The cyclization is proposed to occur via formation of an imidoyl phosphonate intermediate that becomes susceptible to nucleophilic attack at nitrogen through the strong electron-withdrawing groups at the imidoyl carbon.

12.
Angew Chem Int Ed Engl ; 60(34): 18478-18483, 2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34157191

RESUMO

Hexafluoroisopropanol (HFIP) was employed as an additive for the generation of 3-(chloromethylene)oxindoles via the chloroacylation of alkyne-tethered carbamoyl chlorides. This reaction avoids the use of a metal catalyst and accesses products in high yields and stereoselectivities. Additionally, this reaction is scalable and proved amenable to a series of product derivatizations, including the synthesis of nintedanib. The reactivity of alkene-tethered carbamoyl chlorides with hexafluoroisopropanol (HFIP) was harnessed towards the synthesis of 2-quinolinones.

13.
Fish Shellfish Immunol ; 108: 116-126, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33285168

RESUMO

Pancreas disease (PD) caused by salmonid alphavirus subtype 3 (SAV3) is a serious disease with large economic impact on farmed Norwegian Atlantic salmon production despite years of use of oil-adjuvanted vaccines against PD (OAVs). In this study, two commercially available PD vaccines, a DNA vaccine (DNAV) and an OAV, were compared in an experimental setting. At approximately 1040° days (dd) at 12 °C post immunization, the fish were challenged with SAV3 by cohabitation 9 days after transfer to sea water. Sampling was done prior to challenge and at 19, 54, and 83 days post-challenge (dpc). When compared to the OAV and control (Saline) groups, the DNAV group had significantly higher SAV3 neutralizing antibody titers after the immunization period, significantly lower SAV3 viremia levels at 19 dpc, significantly reduced transmission of SAV3 to naïve fish in the latter part of the viremic phase, significantly higher weight gain post-challenge, and significantly reduced prevalence and/or severity of SAV-induced morphologic changes in target organs. The DNAV group had also significantly higher post-challenge survival compared to the Saline group, but not to the OAV group. The data suggest that use of DNAV may reduce the economic impact of PD by protecting against destruction of the pancreas tissue and subsequent growth impairment which is the most common and costly clinical outcome of this disease.


Assuntos
Infecções por Alphavirus/virologia , Alphavirus/imunologia , Doenças dos Peixes/prevenção & controle , Pancreatopatias/veterinária , Salmo salar , Vacinas Virais/imunologia , Infecções por Alphavirus/prevenção & controle , Animais , Doenças dos Peixes/virologia , Pancreatopatias/prevenção & controle , Pancreatopatias/virologia , Vacinas de DNA/imunologia
14.
J Virol ; 95(5)2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33328313

RESUMO

Infectious bursal disease virus (IBDV), the best characterized member of the Birnaviridae family, is a highly relevant avian pathogen causing both acute and persistent infections in different avian hosts. Here, we describe the establishment of clonal, long-term, productive persistent IBDV infections in DF-1 chicken embryonic fibroblasts. Although virus yields in persistently-infected cells are exceedingly lower than those detected in acutely infected cells, the replication fitness of viruses isolated from persistently-infected cells is higher than that of the parental virus. Persistently-infected DF-1 and IBDV-cured cell lines derived from them do not respond to type I interferon (IFN). High-throughput genome sequencing revealed that this defect is due to mutations affecting the IFNα/ß receptor subunit 2 (IFNAR2) gene resulting in the expression of IFNAR2 polypeptides harbouring large C-terminal deletions that abolish the signalling capacity of IFNα/ß receptor complex. Ectopic expression of a recombinant chicken IFNAR2 gene efficiently rescues IFNα responsiveness. IBDV-cured cell lines derived from persistently infected cells exhibit a drastically enhanced susceptibility to establishing new persistent IBDV infections. Additionally, experiments carried out with human HeLa cells lacking the IFNAR2 gene fully recapitulate results obtained with DF-1 cells, exhibiting a highly enhanced capacity to both survive the acute IBDV infection phase and to support the establishment of persistent IBDV infections. Results presented here show that the inactivation of the JAK-STAT signalling pathway significantly reduces the apoptotic response induced by the infection, hence facilitating the establishment and maintenance of IBDV persistent infections.IMPORTANCE Members of the Birnaviridae family, including infectious bursal disease virus (IBDV), exhibit a dual behaviour, causing acute infections that are often followed by the establishment of life-long persistent asymptomatic infections. Indeed, persistently infected specimens might act as efficient virus reservoirs, hence potentially contributing to virus dissemination. Despite the key importance of this biological trait, information about mechanisms triggering IBDV persistency is negligible. Our report evidences the capacity of IBDV, a highly relevant avian pathogen, to establishing long-term, productive, persistent infections in both avian and human cell lines. Data presented here provide novel and direct evidence about the crucial role of type I IFNs on the fate of IBDV-infected cells and their contribution to controlling the establishment of IBDV persistent infections. The use of cell lines unable to respond to type I IFNs opens a promising venue to unveiling additional factors contributing to IBDV persistency.

15.
Sci Rep ; 10(1): 13232, 2020 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-32764646

RESUMO

Dryland wetlands are resilient ecosystems that can adapt to extreme periodic drought-flood episodes. Climate change projections show increased drought severity in drylands that could compromise wetland resilience and reduce important habitat services. These recognized risks have been difficult to evaluate due to our limited capacity to establish comprehensive relationships between flood-drought episodes and vegetation responses at the relevant spatiotemporal scales. We address this issue by integrating detailed spatiotemporal flood-drought simulations with remotely sensed vegetation responses to water regimes in a dryland wetland known for its highly variable inundation. We show that a combination of drought tolerance and dormancy strategies allow wetland vegetation to recover after droughts and recolonize areas invaded by terrestrial species. However, climate change scenarios show widespread degradation during drought and limited recovery after floods. Importantly, the combination of degradation extent and increase in drought duration is critical for the habitat services wetland systems provide for waterbirds and fish.

16.
Sci Total Environ ; 726: 138581, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32348947

RESUMO

Dryland wetlands are ecosystems of high ecological importance as they serve as habitat sanctuaries for aquatic and terrestrial biota in areas with very few resources; therefore, the study of such environments is of major importance for the conservation of biodiversity in arid and semi-arid areas. The vegetation organization in these ecosystems is driven by the water regime as the main driver, but local processes like seed banks and soil resources redistribution also play a crucial role in determining the spatial distribution of the vegetation. Assessment of vegetation dynamics and long-term resilience requires the use of realistic models that can integrate the water regime and that can continuously simulate vegetation extent and conditions under flood-drought cycles. Here we study the influence of the water regime as the main driver of the vegetation. We apply a vegetation-modelling framework to compare the performance of a simplified model at the cell scale and a model integrated at a patch scale. Our results show that aggregating the analysis of vegetation dynamics at the patch scale allows for the incorporation of the effects of both local drivers (acting within the patch) as well as the global drivers (acting over the patch as a whole). The water regime acts as a global driver for the vegetation and indirectly affects the local drivers. Our patch scale model successfully captures wetland vegetation dynamics using the water regime as the main driver for representing changes in the vegetation and assessment of the wetland resilience under flood-drought periods.


Assuntos
Ecossistema , Áreas Alagadas , Biodiversidade , Inundações , Solo
17.
J Am Chem Soc ; 142(20): 9510-9517, 2020 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-32337994

RESUMO

An asymmetric hydroarylative cyclization of enynes involving a C-H bond cleavage is reported. The cobalt-catalyzed cascade generates three new bonds in an atom-economical fashion. The products were obtained in excellent yields and excellent enantioselectivities as single diastereo- and regioisomers. Preliminary mechanistic studies indicate that the reaction shows no intermolecular C-H crossover. This work highlights the potential of cobalt catalysis in C-H bond functionalization and enantioselective domino reactivity.

18.
PLoS One ; 14(7): e0219428, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31306441

RESUMO

Autophagy is a conserved eukaryotic process that mediates lysosomal degradation of cytoplasmic macromolecules and damaged organelles, also exerting an important role in the elimination of intracellular pathogens. Despite the antiviral role of autophagy, many studies suggest that some positive-stranded RNA viruses exploit this pathway to facilitate their own replication. In this study, we demonstrate that the equine torovirus Berne virus (BEV), the prototype member of the Torovirus genus (Coronaviridae Family, Nidovirales Order), induces autophagy at late times post-infection. Conversion of microtubule associated protein 1B light chain 3 (LC3) from cytosolic (LC3 I) to the membrane associated form (LC3 II), a canonical marker of autophagosome formation, is enhanced in BEV infected cells. However, neither autophagy induction, via starvation, nor pharmacological blockade significantly affect BEV replication. Similarly, BEV infection is not altered in autophagy deficient cells lacking either Beclin 1 or LC3B protein expression. Unexpectedly, the cargo receptor p62, a selective autophagy receptor, aggregates within the region where the BEV main protease (Mpro) localizes. This finding, coupled with observation that BEV replication also induces ER stress at the time when selective autophagy is taking place, suggests that the autophagy pathway is activated in response to the hefty accumulation of virus-encoded polypeptides during the late phase of BEV infection.


Assuntos
Autofagia , Infecções por Torovirus/virologia , Torovirus/fisiologia , Replicação Viral , Animais , Autofagossomos , Proteína Beclina-1/metabolismo , Proteínas de Fluorescência Verde/metabolismo , Células HEK293 , Cavalos , Humanos , Lisossomos/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Fagossomos/metabolismo , Transdução de Sinais , Infecções por Torovirus/fisiopatologia
19.
Org Lett ; 20(21): 6915-6919, 2018 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-30338688

RESUMO

The use of ammonium halide salts as metal hydride precursors in a new Pd-catalyzed cycloisomerization of 1,6-diynes, which affords unexplored silylated 2-azafluorenes, is reported. This cascade process includes the addition of a Pd-hydride species to a π-system, intramolecular carbopalladation, and C(sp2)-H bond activation. A variety of functional groups are tolerated, and the synthetic utility of the resulting products has been demonstrated by a series of derivatizations.

20.
Org Lett ; 20(14): 4367-4370, 2018 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-29975065

RESUMO

A palladium-catalyzed intramolecular carbopalladation, intramolecular C-H bond activation, and alkyne insertion sequence for the generation of dihydrobenzoindolones is described. Products are obtained in moderate to excellent yields as single regioisomers. Various functional groups on both reaction partners were tolerated, and the scalability of this method was determined.

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