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Lignocellulose is mainly composed of hydrophobic lignin and hydrophilic polysaccharide polymers, contributing to an indispensable carbon resource for green biorefineries1,2. When chemically treated, lignin is compromised owing to detrimental intra- and intermolecular crosslinking that hampers downstream process3,4. The current valorization paradigms aim to avoid the formation of new C-C bonds, referred to as condensation, by blocking or stabilizing the vulnerable moieties of lignin5-7. Although there have been efforts to enhance biomass utilization through the incorporation of phenolic additives8,9, exploiting lignin's proclivity towards condensation remains unproven for valorizing both lignin and carbohydrates to high-value products. Here we leverage the proclivity by directing the C-C bond formation in a catalytic arylation pathway using lignin-derived phenols with high nucleophilicity. The selectively condensed lignin, isolated in near-quantitative yields while preserving its prominent cleavable ß-ether units, can be unlocked in a tandem catalytic process involving aryl migration and transfer hydrogenation. Lignin in wood is thereby converted to benign bisphenols (34-48 wt%) that represent performance-advantaged replacements for their fossil-based counterparts. Delignified pulp from cellulose and xylose from xylan are co-produced for textile fibres and renewable chemicals. This condensation-driven strategy represents a key advancement complementary to other promising monophenol-oriented approaches targeting valuable platform chemicals and materials, thereby contributing to holistic biomass valorization.
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Compostos Benzidrílicos , Biomassa , Fracionamento Químico , Lignina , Fenóis , Compostos Benzidrílicos/química , Compostos Benzidrílicos/metabolismo , Catálise , Celulose/química , Celulose/metabolismo , Fracionamento Químico/métodos , Hidrogenação , Lignina/química , Lignina/metabolismo , Fenóis/química , Fenóis/metabolismo , Madeira/química , Xilanos/química , Xilanos/metabolismo , Xilose/química , Xilose/metabolismo , Combustíveis Fósseis , TêxteisRESUMO
Self-amplifying mRNA (SAM) vaccines can be rapidly deployed in the event of disease outbreaks. A legitimate safety concern is the potential for recombination between alphavirus-based SAM vaccines and circulating viruses. This theoretical risk needs to be assessed in the regulatory process for SAM vaccine approval. Herein, we undertake extensive in vitro and in vivo assessments to explore recombination between SAM vaccine and a wide selection of alphaviruses and a coronavirus. SAM vaccines were found to effectively limit alphavirus co-infection through superinfection exclusion, although some co-replication was still possible. Using sensitive cell-based assays, replication-competent alphavirus chimeras were generated in vitro as a result of rare, but reproducible, RNA recombination events. The chimeras displayed no increased fitness in cell culture. Viable alphavirus chimeras were not detected in vivo in C57BL/6J, Rag1-/- and Ifnar-/- mice, in which high levels of SAM vaccine and alphavirus co-replicated in the same tissue. Furthermore, recombination between a SAM-spike vaccine and a swine coronavirus was not observed. In conclusion we state that although the ability of SAM vaccines to recombine with alphaviruses might be viewed as an environmental safety concern, several key factors substantially mitigate against in vivo emergence of chimeric viruses from SAM vaccine recipients.
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Alphavirus , Recombinação Genética , Vacinas de mRNA , Animais , Camundongos , Alphavirus/genética , Alphavirus/imunologia , Camundongos Endogâmicos C57BL , Humanos , Receptor de Interferon alfa e beta/genética , Replicação Viral , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/imunologia , Vacinas Sintéticas/imunologia , Vacinas Sintéticas/efeitos adversos , Camundongos Knockout , SARS-CoV-2/genética , SARS-CoV-2/imunologia , Vacinas Virais/imunologia , Vacinas Virais/genética , Vacinas Virais/efeitos adversosRESUMO
Two-dimensional (2D) zeolite, with a high aspect ratio, has more open skeletons and accessible active sites than its three-dimensional (3D) counterpart. However, traditional methods of obtaining 2D zeolites often cause structural damage and widespread skeleton defects, hindering efficient selectivity in molecular separation. In this study, we present, for the first time, a direct epitaxial synthesis of 2D zeolite (Epi-MWW) guided by hexagonal boron nitride (h-BN) with a coincidence matching of site lattices to MWW zeolite. The as-grown Epi-MWW zeolite possesses a high crystallinity and intact hexagonal 2D morphology, with an average thickness of 10 nm and an aspect ratio of over 50. Thanks to its excellent molecular accessibility, the diffusion time constants of o-xylene (OX) and p-xylene (PX) are as 12 and 133 times higher than those of conventional MCM-22, respectively; the PX/OX selectivity of Epi-MWW is 7.4 times better than MCM-22 as calculated by the ideal adsorbed solution theory.
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Malignant melanoma (MM) is a highly invasive and therapeutically resistant skin malignancy, posing a significant clinical challenge in its treatment. Programmed cell death plays a crucial role in the occurrence and progression of MM. Sphingolipids (SP), as a class of bioactive lipids, may be associated with many kinds of diseases. SPs regulate various forms of programmed cell death in tumors, including apoptosis, necroptosis, ferroptosis, and more. This review will delve into the mechanisms by which different types of SPs modulate various forms of programmed cell death in MM, such as their regulation of cell membrane permeability and signaling pathways, and how they influence the survival and death fate of MM cells. An in-depth exploration of the role of SPs in programmed cell death in MM aids in unraveling the molecular mechanisms of melanoma development and holds significant importance in developing novel therapeutic strategies.
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Mayaro virus (MAYV) is a mosquito-transmitted alphavirus that causes often debilitating rheumatic disease in tropical Central and South America. There are currently no licensed vaccines or antiviral drugs available for MAYV disease. Here, we generated Mayaro virus-like particles (VLPs) using the scalable baculovirus-insect cell expression system. High-level secretion of MAYV VLPs in the culture fluid of Sf9 insect cells was achieved, and particles with a diameter of 64 to 70 nm were obtained after purification. We characterize a C57BL/6J adult wild-type mouse model of MAYV infection and disease and used this model to compare the immunogenicity of VLPs from insect cells with that of VLPs produced in mammalian cells. Mice received two intramuscular immunizations with 1 µg of nonadjuvanted MAYV VLPs. Potent neutralizing antibody responses were generated against the vaccine strain, BeH407, with comparable activity seen against a contemporary 2018 isolate from Brazil (BR-18), whereas neutralizing activity against chikungunya virus was marginal. Sequencing of BR-18 illustrated that this virus segregates with genotype D isolates, whereas MAYV BeH407 belongs to genotype L. The mammalian cell-derived VLPs induced higher mean neutralizing antibody titers than those produced in insect cells. Both VLP vaccines completely protected adult wild-type mice against viremia, myositis, tendonitis, and joint inflammation after MAYV challenge. IMPORTANCE Mayaro virus (MAYV) is associated with acute rheumatic disease that can be debilitating and can evolve into months of chronic arthralgia. MAYV is believed to have the potential to emerge as a tropical public health threat, especially if it develops the ability to be efficiently transmitted by urban mosquito vectors, such as Aedes aegypti and/or Aedes albopictus. Here, we describe a scalable virus-like particle vaccine against MAYV that induced neutralizing antibodies against a historical and a contemporary isolate of MAYV and protected mice against infection and disease, providing a potential new intervention for MAYV epidemic preparedness.
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Aedes , Alphavirus , Vírus Chikungunya , Doenças Reumáticas , Vacinas de Partículas Semelhantes a Vírus , Animais , Camundongos , Vacinas de Partículas Semelhantes a Vírus/genética , Camundongos Endogâmicos C57BL , Alphavirus/genética , Brasil , Anticorpos Neutralizantes , MamíferosRESUMO
How well mouse models recapitulate the transcriptional profiles seen in humans remains debatable, with both conservation and diversity identified in various settings. Herein we use RNA-Seq data and bioinformatics approaches to analyze the transcriptional responses in SARS-CoV-2 infected lungs, comparing 4 human studies with the widely used K18-hACE2 mouse model, a model where hACE2 is expressed from the mouse ACE2 promoter, and a model that uses a mouse adapted virus and wild-type mice. Overlap of single copy orthologue differentially expressed genes (scoDEGs) between human and mouse studies was generally poor (≈15-35%). Rather than being associated with batch, sample treatment, viral load, lung damage or mouse model, the poor overlaps were primarily due to scoDEG expression differences between species. Importantly, analyses of immune signatures and inflammatory pathways illustrated highly significant concordances between species. As immunity and immunopathology are the focus of most studies, these mouse models can thus be viewed as representative and relevant models of COVID-19.
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COVID-19 , Enzima de Conversão de Angiotensina 2/genética , Animais , COVID-19/genética , Modelos Animais de Doenças , Expressão Gênica , Humanos , Pulmão , Camundongos , Camundongos Transgênicos , Peptidil Dipeptidase A/metabolismo , SARS-CoV-2/genéticaRESUMO
Most vertebrate RNA viruses show pervasive suppression of CpG and UpA dinucleotides, closely resembling the dinucleotide composition of host cell transcriptomes. In contrast, CpG suppression is absent in both invertebrate mRNA and RNA viruses that exclusively infect arthropods. Arthropod-borne (arbo) viruses are transmitted between vertebrate hosts by invertebrate vectors and thus encounter potentially conflicting evolutionary pressures in the different cytoplasmic environments. Using a newly developed Zika virus (ZIKV) model, we have investigated how demands for CpG suppression in vertebrate cells can be reconciled with potentially quite different compositional requirements in invertebrates and how this affects ZIKV replication and transmission. Mutant viruses with synonymously elevated CpG or UpA dinucleotide frequencies showed attenuated replication in vertebrate cell lines, which was rescued by knockout of the zinc-finger antiviral protein (ZAP). Conversely, in mosquito cells, ZIKV mutants with elevated CpG dinucleotide frequencies showed substantially enhanced replication compared to wild type. Host-driven effects on virus replication attenuation and enhancement were even more apparent in mouse and mosquito models. Infections with CpG- or UpA-high ZIKV mutants in mice did not cause typical ZIKV-induced tissue damage and completely protected mice during subsequent challenge with wild-type virus, which demonstrates their potential as live-attenuated vaccines. In contrast, the CpG-high mutants displayed enhanced replication in Aedes aegypti mosquitoes and a larger proportion of mosquitoes carried infectious virus in their saliva. These findings show that mosquito cells are also capable of discriminating RNA based on dinucleotide composition. However, the evolutionary pressure on the CpG dinucleotides of viral genomes in arthropod vectors directly opposes the pressure present in vertebrate host cells, which provides evidence that an adaptive compromise is required for arbovirus transmission. This suggests that the genome composition of arbo flaviviruses is crucial to maintain the balance between high-level replication in the vertebrate host and persistent replication in the mosquito vector.
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Evolução Molecular , Genoma Viral/genética , Interações Hospedeiro-Patógeno/genética , Zika virus/genética , Células A549 , Aedes/virologia , Animais , Composição de Bases/fisiologia , Sequência de Bases/genética , Linhagem Celular , Chlorocebus aethiops , Ilhas de CpG/fisiologia , Fosfatos de Dinucleosídeos/análise , Fosfatos de Dinucleosídeos/genética , Adaptação ao Hospedeiro/genética , Humanos , Masculino , Mamíferos/virologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mosquitos Vetores/genética , Mosquitos Vetores/virologia , RNA Viral/química , RNA Viral/genética , Seleção Genética/fisiologia , Células Vero , Infecção por Zika virus/genética , Infecção por Zika virus/transmissão , Infecção por Zika virus/virologiaRESUMO
Due to the rise in temperature and sea level caused by climate change, the detection rate of aflatoxin B1 (AFB1) in food crops has increased dramatically, and the frequency and severity of aflatoxicosis in humans and animals are also increasing. AFB1 has strong hepatotoxicity, causing severe liver damage and even cancer. However, the mechanism of AFB1 hepatotoxicity remains unclear. By integrating network toxicology, molecular docking and in vivo experiments, this research was designed to explore the potential hepatotoxicity mechanisms of AFB1. Thirty-three intersection targets for AFB1-induced liver damage were identified using online databases. PI3K/AKT1, MAPK, FOXO1 signaling pathways, and apoptosis were significantly enriched. In addition, the proteins of ALB, AKT1, PIK3CG, MAPK8, HSP90AA1, PPARA, MAPK1, EGFR, FOXO1, and IGF1 exhibited good affinity with AFB1. In vivo experiments, significant pathological changes occurred in the liver of mice. AFB1 induction increased the expression levels of EGFR, ERK, and FOXO1, and decreased the expression levsls of PI3K and AKT1. Moreover, AFB1 treatment caused an increase in Caspase3 expression, and a decrease in Bcl2/Bax ratio. By combining network toxicology with in vivo experiments, this study confirms for the first time that AFB1 promotes the FOXO1 signaling pathway by inactivating PI3K/AKT1 and activating EGFR/ERK signaling pathways, hence aggravating hepatocyte apoptosis. This research provides new strategies for studying the toxicity of environmental pollutants and new possible targets for the development of hepatoprotective drugs.
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Aflatoxina B1 , Doença Hepática Induzida por Substâncias e Drogas , Humanos , Camundongos , Animais , Simulação de Acoplamento Molecular , Aflatoxina B1/toxicidade , Fígado/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Receptores ErbB/metabolismoRESUMO
SARS-CoV-2 uses the human ACE2 (hACE2) receptor for cell attachment and entry, with mouse ACE2 (mACE2) unable to support infection. Herein we describe an ACE2-lentivirus system and illustrate its utility for in vitro and in vivo SARS-CoV-2 infection models. Transduction of non-permissive cell lines with hACE2 imparted replication competence, and transduction with mACE2 containing N30D, N31K, F83Y and H353K substitutions, to match hACE2, rescued SARS-CoV-2 replication. Intrapulmonary hACE2-lentivirus transduction of C57BL/6J mice permitted significant virus replication in lung epithelium. RNA-Seq and histological analyses illustrated that this model involved an acute inflammatory disease followed by resolution and tissue repair, with a transcriptomic profile similar to that seen in COVID-19 patients. hACE2-lentivirus transduction of IFNAR-/- and IL-28RA-/- mouse lungs was used to illustrate that loss of type I or III interferon responses have no significant effect on virus replication. However, their importance in driving inflammatory responses was illustrated by RNA-Seq analyses. We also demonstrate the utility of the hACE2-lentivirus transduction system for vaccine evaluation in C57BL/6J mice. The ACE2-lentivirus system thus has broad application in SARS-CoV-2 research, providing a tool for both mutagenesis studies and mouse model development.
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Enzima de Conversão de Angiotensina 2 , COVID-19 , Perfilação da Expressão Gênica , Lentivirus , SARS-CoV-2 , Transdução Genética , Enzima de Conversão de Angiotensina 2/biossíntese , Enzima de Conversão de Angiotensina 2/genética , Animais , COVID-19/genética , COVID-19/metabolismo , Chlorocebus aethiops , Modelos Animais de Doenças , Humanos , Camundongos , Camundongos Knockout , SARS-CoV-2/genética , SARS-CoV-2/metabolismo , Células VeroRESUMO
Zika virus (ZIKV) strains are classified into the African and Asian genotypes. The higher virulence of the African MR766 strain, which has been used extensively in ZIKV research, in adult IFNα/ß receptor knockout (IFNAR-/-) mice is widely viewed as an artifact associated with mouse adaptation due to at least 146 passages in wild-type suckling mouse brains. To gain insights into the molecular determinants of MR766's virulence, a series of genes from MR766 were swapped with those from the Asian genotype PRVABC59 isolate, which is less virulent in IFNAR-/- mice. MR766 causes 100% lethal infection in IFNAR-/- mice, but when the prM gene of MR766 was replaced with that of PRVABC59, the chimera MR/PR(prM) showed 0% lethal infection. The reduced virulence was associated with reduced neuroinvasiveness, with MR766 brain titers ≈3 logs higher than those of MR/PR(prM) after subcutaneous infection, but was not significantly different in brain titers of MR766 and MR/PR(prM) after intracranial inoculation. MR/PR(prM) also showed reduced transcytosis when compared with MR766 in vitro. The high neuroinvasiveness of MR766 in IFNAR-/- mice could be linked to the 10 amino acids that differ between the prM proteins of MR766 and PRVABC59, with 5 of these changes affecting positive charge and hydrophobicity on the exposed surface of the prM protein. These 10 amino acids are highly conserved amongst African ZIKV isolates, irrespective of suckling mouse passage, arguing that the high virulence of MR766 in adult IFNAR-/- mice is not the result of mouse adaptation.
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Proteínas do Envelope Viral/genética , Virulência/genética , Infecção por Zika virus/virologia , Zika virus/genética , Zika virus/patogenicidade , Animais , Barreira Hematoencefálica , Permeabilidade Capilar , Genótipo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Zika virus/metabolismoRESUMO
Poxvirus systems have been extensively used as vaccine vectors. Herein a RNA-Seq analysis of intramuscular injection sites provided detailed insights into host innate immune responses, as well as expression of vector and recombinant immunogen genes, after vaccination with a new multiplication defective, vaccinia-based vector, Sementis Copenhagen Vector. Chikungunya and Zika virus immunogen mRNA and protein expression was associated with necrosing skeletal muscle cells surrounded by mixed cellular infiltrates. The multiple adjuvant signatures at 12 hours post-vaccination were dominated by TLR3, 4 and 9, STING, MAVS, PKR and the inflammasome. Th1 cytokine signatures were dominated by IFNγ, TNF and IL1ß, and chemokine signatures by CCL5 and CXCL12. Multiple signatures associated with dendritic cell stimulation were evident. By day seven, vaccine transcripts were absent, and cell death, neutrophil, macrophage and inflammation annotations had abated. No compelling arthritis signatures were identified. Such injection site vaccinology approaches should inform refinements in poxvirus-based vector design.
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Vetores Genéticos/administração & dosagem , Imunidade Inata/imunologia , Reação no Local da Injeção/imunologia , Vacinação/métodos , Vacinas Sintéticas/administração & dosagem , Vacínia/imunologia , Infecção por Zika virus/imunologia , Animais , Feminino , Vetores Genéticos/genética , Genoma Viral , Camundongos , Camundongos Endogâmicos C57BL , RNA-Seq , Vacinas Sintéticas/imunologia , Vacínia/genética , Vacínia/metabolismo , Vacínia/virologia , Vaccinia virus/isolamento & purificação , Vacinologia , Zika virus/isolamento & purificação , Infecção por Zika virus/genética , Infecção por Zika virus/metabolismo , Infecção por Zika virus/virologiaRESUMO
Aflatoxin B1 (AFB1) is the most dangerous and abundant mycotoxin, which is toxic to almost all animals, and poultry is more sensitive to AFB1 toxicity. Ingesting AFB1-contaminated feed can cause significant liver damage and brings serious harm to poultry, which greatly restricts the development of the poultry industry. The present research was implemented to explore the intervention effect and its mechanism of taraxasterol on liver damage induced by AFB1 in broiler chickens. The liver damage model in broiler chickens was established by feeding 0.5 mg/kg AFB1 feed, and taraxasterol (25, 50 and 100 mg/kg BW, respectively) was given in the drinking water for 21 days. The growth performance, liver function, oxidative stress, apoptosis and autophagy were evaluated. The results showed that taraxasterol increased BW and reduced feed-to-gain ratio of broiler chickens induced by AFB1. Taraxasterol improved the levels of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyltransferase (GGT), total bilirubin (TBIL) and alkaline phosphatase (ALP), and attenuated hepatic histopathological changes induced by AFB1. Meantime, taraxasterol down-regulated cytochrome P450 (CYP450) enzyme system CYP1A1 and CYP2A6 mRNA expression, inhibited the overproduction of reactive oxygen species (ROS) and malondialdehyde (MDA), and enhanced the activities of antioxidant enzymes glutathione (GSH) and catalase (CAT) and the content of antioxidant superoxide dismutase (SOD) of the liver in broiler chickens induced by AFB1. Furthermore, taraxasterol up-regulated the mRNA and protein expression of hepatic nuclear factor E2 related factor 2 (Nrf2), heme oxygenase 1 (HO-1) and NAD(P)H: quinone oxidoreductase 1 (NQO1), and down-regulated the expression of hepatic kelch like ECH associated protein 1 (Keap1) induced by AFB1 in Keap1/Nrf2 signaling pathway. The ultrastructural observation and RT-qPCR results found that taraxasterol inhibited apoptosis of hepatocytes, up-regulated the expression of B-cell lymphoma-2 (Bcl-2) mRNA and down-regulated the expression of Bax and caspase3 mRNA. Further, taraxasterol restored the autophagy of hepatocytes and down-regulated the mRNA expression of phosphatidylinositol 3-kinase K (PI3K), protein kinase B (AKT) and mammalian target of rapamycin (mTOR) in AFB1-induced liver of broiler chickens. The above results indicate that taraxasterol alleviates liver damage induced by AFB1 in broiler chickens through regulation of Keap1/Nrf2 signaling pathway to exert its antioxidant effect, mitochondrial apoptosis pathway to improve anti-apoptotic ability and PI3K/AKT/mTOR pathway to restore autophagy.
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Antioxidantes , Proteínas Proto-Oncogênicas c-akt , Animais , Antioxidantes/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Galinhas/metabolismo , Aflatoxina B1/toxicidade , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Estresse Oxidativo , Fígado , Apoptose , Glutationa/metabolismo , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , RNA Mensageiro/metabolismo , Autofagia , Mamíferos/metabolismoRESUMO
BACKGROUND: There is evidence that long non-coding RNA (lncRNA) is related to genetic stability. However, the complex biological functions of these lncRNAs are unclear. METHOD: TCGA - KIRC lncRNAs expression matrix and somatic mutation information data were obtained from TCGA database. "GSVA" package was applied to evaluate the genomic related pathway in each samples. GO and KEGG analysis were performed to show the biological function of lncRNAs-mRNAs. "Survival" package was applied to determine the prognostic significance of lncRNAs. Multivariate Cox proportional hazard regression analysis was applied to conduct lncRNA prognosis model. RESULTS: In the present study, we applied computational biology to identify genome-related long noncoding RNA and identified 26 novel genomic instability-associated lncRNAs in clear cell renal cell carcinoma. We identified a genome instability-derived six lncRNA-based gene signature that significantly divided clear renal cell samples into high- and low-risk groups. We validated it in test cohorts. To further elucidate the role of the six lncRNAs in the model's genome stability, we performed a gene set variation analysis (GSVA) on the matrix. We performed Pearson correlation analysis between the GSVA scores of genomic stability-related pathways and lncRNA. It was determined that LINC00460 and LINC01234 could be used as critical factors in this study. They may influence the genome stability of clear cell carcinoma by participating in mediating critical targets in the base excision repair pathway, the DNA replication pathway, homologous recombination, mismatch repair pathway, and the P53 signaling pathway. CONCLUSION SUBSECTIONS: These data suggest that LINC00460 and LINC01234 are crucial for the stability of the clear cell renal cell carcinoma genome.
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Carcinoma de Células Renais/genética , Biologia Computacional/métodos , Instabilidade Genômica/genética , Neoplasias Renais/genética , RNA Longo não Codificante/genética , Carcinoma de Células Renais/patologia , Humanos , Neoplasias Renais/patologiaRESUMO
BACKGROUND: The international SARS-CoV-2 pandemic has resulted in an urgent need to identify new anti-viral drugs for treatment of COVID-19. The initial step to identifying potential candidates usually involves in vitro screening that includes standard cytotoxicity controls. Under-appreciated is that viable, but stressed or otherwise compromised cells, can also have a reduced capacity to replicate virus. A refinement proposed herein for in vitro drug screening thus includes a simple growth assay to identify drug concentrations that cause cellular stress or "cytomorbidity", as distinct from cytotoxicity or loss of viability. METHODS: A simple rapid bioassay is presented for antiviral drug screening using Vero E6 cells and inhibition of SARS-CoV-2 induced cytopathic effects (CPE) measured using crystal violet staining. We use high cell density for cytotoxicity assays, and low cell density for cytomorbidity assays. RESULTS: The assay clearly illustrated the anti-viral activity of remdesivir, a drug known to inhibit SARS-CoV-2 replication. In contrast, nitazoxanide, oleuropein, cyclosporine A and ribavirin all showed no ability to inhibit SARS-CoV-2 CPE. Hydroxychloroquine, cyclohexamide, didemnin B, γ-mangostin and linoleic acid were all able to inhibit viral CPE at concentrations that did not induce cytotoxicity. However, these drugs inhibited CPE at concentrations that induced cytomorbidity, indicating non-specific anti-viral activity. CONCLUSIONS: We describe the methodology for a simple in vitro drug screening assay that identifies potential anti-viral drugs via their ability to inhibit SARS-CoV-2-induced CPE. The additional growth assay illustrated how several drugs display anti-viral activity at concentrations that induce cytomorbidity. For instance, hydroxychloroquine showed anti-viral activity at concentrations that slow cell growth, arguing that its purported in vitro anti-viral activity arises from non-specific impairment of cellular activities. The cytomorbidity assay can therefore rapidly exclude potential false positives.
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Antivirais/farmacologia , SARS-CoV-2/efeitos dos fármacos , Animais , Antivirais/química , Bioensaio , Chlorocebus aethiops , Efeito Citopatogênico Viral/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos/métodos , Concentração Inibidora 50 , Células Vero , Replicação Viral/efeitos dos fármacosRESUMO
In this paper, we propose a design utilizing two identically parallel-aligned nematic liquid crystal (LC) plates for fast-response and polarization-independent phase modulator. Driven by synchronized voltage signals, such a polarizer-free variable phase modulator shows a wide tunable range from zero to more than 3π, back and forth at 532nm. Due to the optical compensation of the two plates, the rise and fall time of the phase retardation corresponds to the switching-on time of the two plates. Several advantages are illustrated based on the optical compensation of two identical parallel-aligned plates. First, zero phase retardation is obtained, which overcomes the residual phase due to surfaced anchored liquid crystal molecules. The second advantage is sub-millisecond response of rise and fall of retardation since simultaneous relaxation of the two plates remains optically hidden during the synchronized voltages fall. This fast-response and polarization-independent phase modulator has great potential for practical use, including optical communications and light field imaging systems.
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An approach for generating cycloidal pattern of liquid crystal (LC) molecules based on interference-free and single exposure is illustrated. The spatial manipulation of polarization state is achieved using birefringent prism and wave plates. And then, the spatially variant polarization of exposure beam is transferred to LC molecules by azo-dye photo-sensitive layer. Consequently, the LC samples fabricated shows periodically cycloidal texture and diffraction efficiency more than 99%. The measured period Λ and diffraction angle are in good consistency with theoretical results. Thus, this exposure method provides an effective and robust way for fabricating large-area LC elements, therefore paving the way for widespread applications of high-performance diffractive LC devices.
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Introduction: Global microplastic (MP) pollution is now well recognized, with humans and animals consuming and inhaling MPs on a daily basis, with a growing body of concern surrounding the potential impacts on human health. Methods: Using a mouse model of mild COVID-19, we describe herein the effects of azide-free 1 µm polystyrene MP beads, co-delivered into lungs with a SARS-CoV-2 omicron BA.5 inoculum. The effect of MPs on the host response to SARS-CoV-2 infection was analysed using histopathology and RNA-Seq at 2 and 6 days post-infection (dpi). Results: Although infection reduced clearance of MPs from the lung, virus titres and viral RNA levels were not significantly affected by MPs, and overt MP-associated clinical or histopathological changes were not observed. However, RNA-Seq of infected lungs revealed that MP exposure suppressed innate immune responses at 2 dpi and increased pro-inflammatory signatures at 6 dpi. The cytokine profile at 6 dpi showed a significant correlation with the 'cytokine release syndrome' signature observed in some COVID-19 patients. Discussion: The findings are consistent with the recent finding that MPs can inhibit phagocytosis of apoptotic cells via binding of Tim4. They also add to a growing body of literature suggesting that MPs can dysregulate inflammatory processes in specific disease settings.
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COVID-19 , Modelos Animais de Doenças , Imunidade Inata , Pulmão , Microplásticos , SARS-CoV-2 , Animais , COVID-19/imunologia , COVID-19/virologia , Imunidade Inata/efeitos dos fármacos , SARS-CoV-2/imunologia , SARS-CoV-2/fisiologia , Camundongos , Pulmão/imunologia , Pulmão/virologia , Pulmão/patologia , Citocinas/metabolismo , Humanos , Pneumonia Viral/imunologia , Pneumonia Viral/virologia , Feminino , Síndrome da Liberação de Citocina/imunologia , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Betacoronavirus/imunologia , PandemiasRESUMO
Getah virus (GETV) is an emerging mosquito-borne virus with economic impact on the livestock industry in East Asia. In this study, we successfully produced GETV virus-like particles (VLPs) in insect cells using the baculovirus expression vector system. We show that the GETV envelope glycoproteins were successfully expressed at the surface of the insect cell and were glycosylated. VLPs were isolated from the culture fluid as enveloped particles of 60-80 nm in diameter. Two 1 µg vaccinations with this GETV VLP vaccine, without adjuvant, generated neutralizing antibody responses and protected wild-type C57/BL6 mice against GETV viremia and arthritic disease. The GETV VLP vaccine may find application as a horse and/or pig vaccine in the future.