Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 56
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
PLoS Pathog ; 20(9): e1012535, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39255317

RESUMO

Kaposi's sarcoma-associated herpesvirus (KSHV) is a double-stranded DNA virus that encodes numerous cellular homologs, including cyclin D, G protein-coupled protein, interleukin-6, and macrophage inflammatory proteins 1 and 2. KSHV vCyclin encoded by ORF72, is the homolog of cellular cyclinD2. KSHV vCyclin can regulate virus replication and cell proliferation by constitutively activating cellular cyclin-dependent kinase 6 (CDK6). However, the regulatory mechanism of KSHV vCyclin has not been fully elucidated. In the present study, we identified a host protein named protein arginine methyltransferase 5 (PRMT5) that interacts with KSHV vCyclin. We further demonstrated that PRMT5 is upregulated by latency-associated nuclear antigen (LANA) through transcriptional activation. Remarkably, knockdown or pharmaceutical inhibition (using EPZ015666) of PRMT5 inhibited the cell cycle progression and cell proliferation of KSHV latently infected tumor cells. Mechanistically, PRMT5 methylates vCyclin symmetrically at arginine 128 and stabilizes vCyclin in a methyltransferase activity-dependent manner. We also show that the methylation of vCyclin by PRMT5 positively regulates the phosphorylate retinoblastoma protein (pRB) pathway. Taken together, our findings reveal an important regulatory effect of PRMT5 on vCyclin that facilitates cell cycle progression and proliferation, which provides a potential therapeutic target for KSHV-associated malignancies.


Assuntos
Ciclo Celular , Proliferação de Células , Herpesvirus Humano 8 , Proteína-Arginina N-Metiltransferases , Proteína-Arginina N-Metiltransferases/metabolismo , Proteína-Arginina N-Metiltransferases/genética , Humanos , Herpesvirus Humano 8/metabolismo , Herpesvirus Humano 8/fisiologia , Metilação , Antígenos Virais/metabolismo , Antígenos Virais/genética , Proteínas Virais/metabolismo , Proteínas Virais/genética , Ciclina D2/metabolismo , Células HEK293 , Replicação Viral/fisiologia , Sarcoma de Kaposi/virologia , Sarcoma de Kaposi/metabolismo , Proteínas Nucleares
2.
Plant Physiol ; 2024 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-39276362

RESUMO

Verticillium wilt (VW) caused by Verticillium dahliae (V. dahliae) is one of the most destructive diseases in cotton (Gossypium spp.). Histone acetylation plays critical roles in plant development and adaptive responses to biotic and abiotic stresses. However, the relevance of histone acetylation in cotton VW resistance remains largely unclear. Here, we identified Histone Deacetylase 5 (GhHDA5) from upland cotton (Gossypium hirsutum L.), as a negative regulator of VW resistance. GhHDA5 expression was responsive to V. dahliae infection. Silencing GhHDA5 in upland cotton led to improved resistance to V. dahliae, while heterologous expression of GhHDA5 in Arabidopsis (Arabidopsis thaliana) compromised V. dahliae tolerance. GhHDA5 repressed the expression of several lignin biosynthesis-related genes, such as 4-coumarate: CoA ligase gene Gh4CL3 and ferulate 5-hydroxylase gene GhF5H, through reducing the acetylation level of Histone H3 Lysine 9 and 14 (H3K9K14ac) at their promoter regions, thereby resulting in an increased deposition of lignin, especially S monomers, in the GhHDA5-silenced cotton plants. The silencing of GhF5H impaired cotton VW tolerance. Additionally, the silencing of GhHDA5 also promoted the production of reactive oxygen species (ROS), elevated the expression of several pathogenesis-related genes (PRs), and altered the content and signaling of the phytohormones salicylic acid (SA), jasmonic acid (JA) and strigolactones (SLs) after V. dahliae infection. Taken together, our findings suggest that GhHDA5 negatively regulates cotton VW resistance through modulating disease-induced lignification and the ROS- and phytohormone-mediated defense response.

3.
J Gene Med ; 26(1): e3599, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37800684

RESUMO

Lung adenocarcinoma (LUAD), a prominent lung cancer subtype, has an underexplored relationship with PANoptosis, a recently discovered mode of tumour cell death. This study incorporated iron death, copper death, scorch death, necrotizing apoptosis and bisulfide death into a pan-death gene set (PANoptosis) and conducted single-cell analysis of scRNA-seq data from 11 LUAD samples. Differentially expressed genes were identified, and Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses were performed. Univariate COX regression and least absolute shrinkage and selection operator (LASSO) regression were used to screen PANoptosis key genes for constructing an LUAD risk model. The model's prognostic performance was evaluated using survival curves, risk scores and validation in the Gene Expression Omnibus database. The study also explored the correlation between risk scores, tumour biological function, immunotherapy, drug sensitivity and immune infiltration. The SMS gene in the PANoptosis model was silenced in two LUAD cell lines for cellular validation. Single-cell analysis revealed eight major cell types and several PANoptosis genes significantly associated with LUAD survival. The risk model demonstrated strong prognostic performance and association with immune infiltration, suggesting PANoptosis involvement in LUAD tumour immunity. Cellular validation further supported these findings. The PANoptosis key risk genes are believed to be closely related to the tumour microenvironment and immune regulation of LUAD, potentially providing valuable insights for early diagnosis and clinical treatment, and broader applications in other tumours and complex diseases.


Assuntos
Adenocarcinoma de Pulmão , Neoplasias Pulmonares , Humanos , Prognóstico , Microambiente Tumoral/genética , Adenocarcinoma de Pulmão/genética , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/genética , Aprendizado de Máquina
4.
PLoS Pathog ; 18(8): e1010744, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35914008

RESUMO

Kaposi's sarcoma-associated herpesvirus (KSHV) is a double-stranded DNA virus with the capacity to establish life-long latent infection. During latent infection, the viral genome persists as a circular episome that associates with cellular histones and exists as a nonintegrated minichromosome in the nucleus of infected cells. Chromatin structure and epigenetic programming are required for the proper control of viral gene expression and stable maintenance of viral DNA. However, there is still limited knowledge regarding how the host regulates the chromatin structure and maintenance of episomal DNA. Here, we found that the cellular protein structural maintenance of chromosome (SMC) complex SMC5/6 recognizes and associates with the KSHV genome to inhibit its replication. The SMC5/6 complex can bind to the KSHV genome and suppress KSHV gene transcription by condensing the viral chromatin and creating a repressive chromatin structure. Correspondingly, KSHV employs an antagonistic strategy by utilizing the viral protein RTA to degrade the SMC5/6 complex and antagonize the inhibitory effect of this complex on viral gene transcription. Interestingly, this antagonistic mechanism of RTA is evolutionarily conserved among γ-herpesviruses. Our work suggests that the SMC5/6 complex is a new host factor that restricts KSHV replication.


Assuntos
Herpesvirus Humano 8 , Proteínas Imediatamente Precoces , Infecção Latente , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Cromatina/metabolismo , Proteínas Cromossômicas não Histona/genética , Regulação Viral da Expressão Gênica , Herpesvirus Humano 8/fisiologia , Humanos , Proteínas Imediatamente Precoces/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Transativadores , Ubiquitina/metabolismo , Latência Viral/genética , Replicação Viral/genética
5.
J Exp Bot ; 2024 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-39303008

RESUMO

Anthocyanins, a group of flavonoids, play diverse roles in plant growth and environmental adaptation. The biosynthesis and accumulation of anthocyanin are regulated by environmental cues, such as high light. However, the precise mechanism underlying anthocyanin biosynthesis under high light conditions remains largely unclear. Here, we report that the R3-MYB repressor MYB-LIKE 2 (MYBL2) negatively regulates high light-induced anthocyanin biosynthesis by repressing two R2R3-MYB activators, PRODUCTION OF ANTHOCYANIN PIGMENT 1 (PAP1) and PAP2, which are core components of the MYB-bHLH-WD40 (MBW) complex. We found that MYBL2 interacts with PAP1/2 and reduces their transcriptional activation activities, thus disrupting the expression of key genes involved in anthocyanin biosynthesis, such as DIHYDROFLAVONOL 4-REDUCTASE (DFR) and TRANSPARENT TESTA 19 (TT19). Additionally, MYBL2 attenuates the transcriptional activation of PAP1 on its own expression, but not PAP2. Conversely, PAP1 collaborates with TT8, a bHLH member of the MBW complex, to activate MYBL2 transcription when excessive anthocyanins are accumulated. Taken together, our findings reveal a negative feedback regulatory module composed of MYBL2 and PAP1 that fine-tunes high light-induced anthocyanin biosynthesis through modulating MBW complex assembly.

6.
Xenobiotica ; 52(8): 943-956, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36222269

RESUMO

Non-specific binding in in vitro metabolism systems leads to an underestimation of the true intrinsic metabolic clearance of compounds being studied. Therefore in vitro binding needs to be accounted for when extrapolating in vitro data to predict the in vivo metabolic clearance of a compound. While techniques exist for experimentally determining the fraction of a compound unbound in in vitro metabolism systems, early in drug discovery programmes computational approaches are often used to estimate the binding in the in vitro system.Experimental fraction unbound data (n = 60) were generated in liver microsomes (fumic) from five commonly used pre-clinical species (rat, mouse, dog, minipig, monkey) and humans. Unbound fraction in incubations with mouse, rat or human hepatocytes was determined for the same 60 compounds. These data were analysed to determine the relationship between experimentally determined binding in the different matrices and across different species. In hepatocytes there was a good correlation between fraction unbound in human and rat (r2=0.86) or mouse (r2=0.82) hepatocytes. Similar correlations were observed between binding in human liver microsomes and microsomes from rat, mouse, dog, Göttingen minipig or monkey liver microsomes (r2 of >0.89, n = 51 - 52 measurements in different species). Physicochemical parameters (logP, pKa and logD) were predicted for all evaluated compounds. In addition, logP and/or logD were measured for a subset of compounds.Binding to human hepatocytes predicted using 5 different methods was compared to the measured data for a set of 59 compounds. The best methods evaluated used measured microsomal binding in human liver microsomes to predict hepatocyte binding. The collated physicochemical data were used to predict the human fumic using four different in silico models for a set of 53-60 compounds. The correlation (r2) and root mean square error between predicted and observed microsomal binding was 0.69 & 0.20, 0.47 & 0.23, 0.56 & 0.21 and 0.54 & 0.26 for the Turner-Simcyp, Austin, Hallifax-Houston and Poulin models, respectively. These analyses were extended to include measured literature values for binding in human liver microsomes for a larger set of compounds (n=697). For the larger dataset of compounds, microsomal binding was well predicted for neutral compounds (r2=0.67 - 0.70) using the Poulin, Austin, or Turner-Simcyp methods but not for acidic or basic compounds (r2<0.5) using any of the models. While the lipophilicity-based models can be used, the in vitro binding should be measured for compounds where more certainty is needed, using appropriately calibrated assays and possibly established weak, moderate, and strong binders as reference compounds to allow comparison across databases.


Assuntos
Hepatócitos , Microssomos Hepáticos , Animais , Cães , Humanos , Camundongos , Ratos , Haplorrinos , Hepatócitos/metabolismo , Taxa de Depuração Metabólica , Microssomos Hepáticos/metabolismo , Modelos Biológicos , Suínos , Porco Miniatura , Reprodutibilidade dos Testes
7.
Entropy (Basel) ; 24(10)2022 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-37420346

RESUMO

In recent years, video stabilization has improved significantly in simple scenes, but is not as effective as it could be in complex scenes. In this study, we built an unsupervised video stabilization model. In order to improve the accurate distribution of key points in the full frame, a DNN-based key-point detector was introduced to generate rich key points and optimize the key points and the optical flow in the largest area of the untextured region. Furthermore, for complex scenes with moving foreground targets, we used a foreground and background separation-based approach to obtain unstable motion trajectories, which were then smoothed. For the generated frames, adaptive cropping was conducted to completely remove the black edges while maintaining the maximum detail of the original frame. The results of public benchmark tests showed that this method resulted in less visual distortion than current state-of-the-art video stabilization methods, while retaining greater detail in the original stable frames and completely removing black edges. It also outperformed current stabilization models in terms of both quantitative and operational speed.

8.
Entropy (Basel) ; 24(2)2022 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-35205460

RESUMO

In recent years, the pedestrian detection technology of a single 2D image has been dramatically improved. When the scene becomes very crowded, the detection performance will deteriorate seriously and cannot meet the requirements of autonomous driving perception. With the introduction of the multi-view method, the task of pedestrian detection in crowded or fuzzy scenes has been significantly improved and has become a widely used method in autonomous driving. In this paper, we construct a double-branch feature fusion structure, the first branch adopts a lightweight structure, the second branch further extracts features and gets the feature map obtained from each layer. At the same time, the receptive field is enlarged by expanding convolution. To improve the speed of the model, the keypoint is used instead of the entire object for regression without an NMS post-processing operation. Meanwhile, the whole model can be learned from end to end. Even in the presence of many people, the method can still perform better on accuracy and speed. In the standard of Wildtrack and MultiviewX dataset, the accuracy and running speed both perform better than the state-of-the-art model, which has great practical significance in the autonomous driving field.

9.
Heart Lung Circ ; 30(2): 288-295, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32690359

RESUMO

BACKGROUND: Renal dysfunction is independently associated with increased early and late mortality after coronary artery bypass graft (CABG) surgery. Off-pump CABG (OPCABG) avoids postoperative complications from the cardiopulmonary bypass, but it is unclear how it is impacted by occult renal dysfunction (ORD). This study aimed to investigate the effects of ORD on early and late outcomes after OPCABG. METHODS: This retrospective and observational cohort study reviewed data on 1,188 patients who underwent first isolated OPCABG with normal serum creatinine (SCr) levels. According to preoperative estimated creatinine clearance (eCrCl) by the Cockcroft-Gault formula, the patients were divided into an ORD group (n=260, eCrCl <60 mL/min/1.73 m2) and a control group (n=928, eCrCl ≥60 mL/min/1.73 m2). RESULTS: The ORD patients presented with older age, higher incidence of small body surface area, hypertension, low preoperative eCrCl, cerebrovascular accident, peripheral vascular disease, New York Heart Association (NYHA) Ⅲ, and high risk score. The prevalence of hospital mortality, postoperative acute kidney injury (AKI), peak postoperative SCr, and prolonged hospital stay were greater in the ORD patients than the control patients. Multivariable logistic regression analysis showed that the ORD patients were at significantly higher risk of postoperative AKI (OR, 2.702; 95% CI, 1.994-3.662) and in-hospital mortality (OR, 2.884; 95% CI, 1.293-6.432). Multivariate Cox proportional hazard models confirmed that ORD was significantly associated with high later mortality (HR, 2.847; 95% CI, 1.262-6.425). CONCLUSIONS: Occult renal dysfunction is an independent risk factor for postoperative AKI in-hospital and later mortality in patients undergoing OPCABG with normal SCr levels.


Assuntos
Injúria Renal Aguda/etiologia , Ponte de Artéria Coronária sem Circulação Extracorpórea/efeitos adversos , Doença da Artéria Coronariana/cirurgia , Taxa de Filtração Glomerular/fisiologia , Complicações Pós-Operatórias , Injúria Renal Aguda/fisiopatologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Período Pré-Operatório
10.
BMC Cardiovasc Disord ; 20(1): 463, 2020 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-33115418

RESUMO

BACKGROUND: Preoperative risk evaluation systems are significant and important to the allocation of medical resources and the communication between doctors and patients. The European System for Cardiac Operative Risk Evaluation II (EuroSCORE II) is widely used in clinical practice. Cardiac troponin T (cTnT) can specifically and accurately reflect myocardial injury. Whether EuroSCORE II can improve the predictive power after integrating with cTnT is still unclear. This study was a retrospective single center study designed to assess the predictive ability of EuroSCORE II integrated with cTnT for patients undergoing isolated off-pump coronary artery bypass grafting (OPCABG). METHODS: This retrospective and observational cohort study included 1887 patients who underwent first isolated OPCABG. cTnT was detected within 48 h before operation in each patient. According to myocardial injury, patients were divided by cTnT into 4 stages. A new risk evaluation system was created through logistic regression with EuroSCORE II and myocardial injury classification as covariates. Then the two risk evaluation systems were comparatively assessed by regression analysis, receiver operator characteristic curves, net reclassification index, Bland-Altman plots and decision curve analysis. RESULTS: There were 43 in-hospital deaths, with a mortality of 2.30% (43/1887). The logistic regression analysis showed that preoperative myocardial injury classification was a significant risk factor for in-hospital mortality in both total cohort (OR 1.491, 95%CI 1.049-2.119) and subsets (OR 1.761, 95%CI 1.102-2.814). The new risk evaluation system has higher calibration and discrimination power than EuroSCORE II, both for overall cohort and subsets. Especially, the new system has obvious advantages in discrimination power in the subset of acute myocardial infarction (AUC 0.813 vs. 0.772, 0.906 vs. 0.841, and 0.715 vs. 0.646, respectively). CONCLUSIONS: Both myocardial injury classification and EuroSCORE II are independent risk factors of in-hospital mortality in OPCABG patients. The new risk evaluation system has higher predictive ability than EuroSCORE II, especially in patients with a recent history of AMI.


Assuntos
Ponte de Artéria Coronária sem Circulação Extracorpórea , Doença da Artéria Coronariana/cirurgia , Técnicas de Apoio para a Decisão , Infarto do Miocárdio/cirurgia , Troponina T/sangue , Idoso , Biomarcadores/sangue , Ponte de Artéria Coronária sem Circulação Extracorpórea/efeitos adversos , Ponte de Artéria Coronária sem Circulação Extracorpórea/mortalidade , Doença da Artéria Coronariana/sangue , Doença da Artéria Coronariana/diagnóstico , Doença da Artéria Coronariana/mortalidade , Feminino , Mortalidade Hospitalar , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/sangue , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/mortalidade , Valor Preditivo dos Testes , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
11.
J Exp Bot ; 70(18): 4849-4864, 2019 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-30972421

RESUMO

It is predicted that high-temperature stress will increasingly affect crop yields worldwide as a result of climate change. In order to determine the genetic basis of thermotolerance of seed-set in maize under field conditions, we performed mapping of quantitative trait loci (QTLs) in a recombinant inbred line (RIL) population using a collection of 8329 specifically developed high-density single-nucleotide polymorphism (SNP) markers, combined with a genome-wide association study (GWAS) of 261 diverse maize lines using 259 973 SNPs. In total, four QTLs and 17 genes associated with 42 SNPs related to thermotolerance of seed-set were identified. Among them, four candidate genes were found in both linkage mapping and GWAS. Thermotolerance of seed-set was increased significantly in near-isogenic lines (NILs) that incorporated the four candidate genes in a susceptible parent background. The expression profiles of two of the four genes showed that they were induced by high temperatures in the maize tassel in a tolerant parent background. Our results indicate that thermotolerance of maize seed-set is regulated by multiple genes each of which has minor effects, with calcium signaling playing a central role. The genes identified may be exploited in breeding programs to improve seed-set and yield of maize under heat stress.


Assuntos
Genes de Plantas/fisiologia , Genoma de Planta , Termotolerância/genética , Zea mays/fisiologia , Mapeamento Cromossômico , Estudo de Associação Genômica Ampla , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Sementes/fisiologia , Zea mays/genética
12.
J Stroke Cerebrovasc Dis ; 28(11): 104363, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31501038

RESUMO

BACKGROUND AND AIM: Renal dysfunction (RD) is prevalent in patients with acute ischemic stroke requiring intravenous thrombolysis. The relationship between renal function and thrombolysis related intracranial hemorrhagic (ICH) complications is contradictory according to previous studies. The current study is to clarify whether RD could increase the risk of symptomatic intracranial hemorrhage (SICH) after recombinant tissue plasminogen activator (IV rtPA) in acute ischemic stroke patients. METHODS: In this observational study, acute ischemic stroke patients who received IV rtPA within 4.5 hours of symptom onset were retrospectively analyzed. Creatinine levels on admission served to calculate glomerular filtration rate (GFR) to estimate RD. SICH was defined with National Institute of Neurological Disorder and Stroke (NINDS, SICHNINDS) or European Cooperative Acute Stroke Study II (ECASS II, SICHECASSII) criteria. Association of RD with SICH was assessed using continuous GFR or binary GFR (RD defined as GFR < 90 ml/minute/1.73 m2). RESULTS: Of 312 patients included, the incidence of SICHNINDS was 7.69%, of SICHECASSII was 5.45%. Patients with RD had higher prevalence of SICHNINDS (12.80% versus 2.03%, P < .001) and SICHECASS II (9.15% versus 1.35%, P = .002). GFR as a continuous variable was associated with SICHNINDS (ORadjust = .97, P = .003), but not with SICHECASS II. GFR less than 90 ml/minute/1.73 m2 remained independently associated with SICHNINDS (ORadjust = 4.79, P = .016), and SICHECASS II (ORadjust = 2.99, P = .032) in multiple logistic regression analysis. CONCLUSIONS: Renal function is independently associated with SICH after IV rtPA thrombolysis. RD is an independent predictor for both SICHNINDS and SICHECASS II. RD should be considered when evaluating the risk of intravenous thrombolysis with IV rtPA.


Assuntos
Isquemia Encefálica/tratamento farmacológico , Fibrinolíticos/efeitos adversos , Taxa de Filtração Glomerular , Hemorragias Intracranianas/induzido quimicamente , Nefropatias/fisiopatologia , Rim/fisiopatologia , Acidente Vascular Cerebral/tratamento farmacológico , Terapia Trombolítica/efeitos adversos , Ativador de Plasminogênio Tecidual/efeitos adversos , Administração Intravenosa , Idoso , Idoso de 80 Anos ou mais , Isquemia Encefálica/diagnóstico , Isquemia Encefálica/epidemiologia , Isquemia Encefálica/fisiopatologia , China/epidemiologia , Feminino , Fibrinolíticos/administração & dosagem , Humanos , Incidência , Hemorragias Intracranianas/diagnóstico , Hemorragias Intracranianas/epidemiologia , Nefropatias/diagnóstico , Nefropatias/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/fisiopatologia , Fatores de Tempo , Ativador de Plasminogênio Tecidual/administração & dosagem , Resultado do Tratamento
13.
J Virol ; 91(16)2017 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-28592532

RESUMO

Infectious bursal disease virus (IBDV) is a double-stranded RNA (dsRNA) virus. Segment A contains two overlapping open reading frames (ORFs), which encode viral proteins VP2, VP3, VP4, and VP5. Segment B contains one ORF and encodes the viral RNA-dependent RNA polymerase, VP1. IBDV ribonucleoprotein complexes are composed of VP1, VP3, and dsRNA and play a critical role in mediating viral replication and transcription during the virus life cycle. In the present study, we identified a cellular factor, VDAC1, which was upregulated during IBDV infection and found to mediate IBDV polymerase activity. VDAC1 senses IBDV infection by interacting with viral proteins VP1 and VP3. This association is caused by RNA bridging, and all three proteins colocalize in the cytoplasm. Furthermore, small interfering RNA (siRNA)-mediated downregulation of VDAC1 resulted in a reduction in viral polymerase activity and a subsequent decrease in viral yield. Moreover, overexpression of VDAC1 enhanced IBDV polymerase activity. We also found that the viral protein VP3 can replace segment A to execute polymerase activity. A previous study showed that mutations in the C terminus of VP3 directly influence the formation of VP1-VP3 complexes. Our immunoprecipitation experiments demonstrated that protein-protein interactions between VDAC1 and VP3 and between VDAC1 and VP1 play a role in stabilizing the interaction between VP3 and VP1, further promoting IBDV polymerase activity.IMPORTANCE The cellular factor VDAC1 controls the entry and exit of mitochondrial metabolites and plays a pivotal role during intrinsic apoptosis by mediating the release of many apoptogenic molecules. Here we identify a novel role of VDAC1, showing that VDAC1 interacts with IBDV ribonucleoproteins (RNPs) and facilitates IBDV replication by enhancing IBDV polymerase activity through its ability to stabilize interactions in RNP complexes. To our knowledge, this is the first report that VDAC1 is specifically involved in regulating IBDV RNA polymerase activity, providing novel insight into virus-host interactions.


Assuntos
Interações Hospedeiro-Patógeno , Vírus da Doença Infecciosa da Bursa/fisiologia , Ribonucleoproteínas/metabolismo , Proteínas Estruturais Virais/metabolismo , Replicação Viral , Canal de Ânion 1 Dependente de Voltagem/metabolismo , Animais , Linhagem Celular , Galinhas , Imunoprecipitação , Ligação Proteica , Mapeamento de Interação de Proteínas , RNA Polimerase Dependente de RNA/metabolismo
14.
J Virol ; 91(5)2017 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-27974565

RESUMO

Autophagy functions as an intrinsic antiviral defense. However, some viruses can subvert or even enhance host autophagic machinery to increase viral replication and pathogenesis. The role of autophagy during avibirnavirus infection, especially late stage infection, remains unclear. In this study, infectious bursal disease virus (IBDV) was used to investigate the role of autophagy in avibirnavirus replication. We demonstrated IBDV induction of autophagy as a significant increase in puncta of LC3+ autophagosomes, endogenous levels of LC3-II, and ultrastructural characteristics typical of autophagosomes during the late stage of infection. Induction of autophagy enhances IBDV replication, whereas inhibition of autophagy impairs viral replication. We also demonstrated that IBDV infection induced autophagosome-lysosome fusion, but without active degradation of their contents. Moreover, inhibition of fusion or of lysosomal hydrolysis activity significantly reduced viral replication, indicating that virions utilized the low-pH environment of acidic organelles to facilitate viral maturation. Using immuno-transmission electron microscopy (TEM), we observed that a large number of intact IBDV virions were arranged in a lattice surrounded by p62 proteins, some of which lay between virions. Additionally, many virions were encapsulated within the vesicular membranes, with an obvious release stage observed by TEM. The autophagic endosomal pathway facilitates low-pH-mediated maturation of viral proteins and membrane-mediated release of progeny virions.IMPORTANCE IBDV is the most extensively studied virus in terms of molecular characteristics and pathogenesis; however, mechanisms underlying the IBDV life cycle require further exploration. The present study demonstrated that autophagy enhances viral replication at the late stage of infection, and the autophagy pathway facilitates IBDV replication complex function and virus assembly, which is critical to completion of the virus life cycle. Moreover, the virus hijacks the autophagic vacuoles to mature in an acidic environment and release progeny virions in a membrane-mediated cell-to-cell manner. This autophagic endosomal pathway is proposed as a new mechanism that facilitates IBDV maturation, release, and reinternalization. This report presents a concordance in exit strategies among some RNA and DNA viruses, which exploit autophagy pathway for their release from cells.


Assuntos
Autofagia , Infecções por Birnaviridae/veterinária , Vírus da Doença Infecciosa da Bursa/fisiologia , Doenças das Aves Domésticas/virologia , Vacúolos/virologia , Animais , Infecções por Birnaviridae/virologia , Linhagem Celular , Embrião de Galinha , Interações Hospedeiro-Patógeno , Evasão da Resposta Imune , Imunidade Inata , Transdução de Sinais , Vacúolos/fisiologia , Internalização do Vírus , Liberação de Vírus , Replicação Viral
15.
Virol J ; 14(1): 38, 2017 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-28222746

RESUMO

BACKGROUND: Chicken anemia virus (CAV) causes anemia and immune suppression, which are important diseases in the poultry industry. CAV VP3, also referred as 'apoptin', has been shown to selectively kill tumor cells, raising great hopes for its utilization as an anticancer therapy. The ability of apoptin to induce apoptosis is closely related to its nuclear localization. The C-terminal region of apoptin contains a bipartite nuclear localization signals (NLS), and a nuclear export signal (NES) is located between the arms of the NLS. Most previous studies have expressed apoptin of different lengths in vitro to understand the relationship between its localization and its induction of apoptosis. METHODS: In this study, we investigated the replication of CAV and its induction of apoptosis in vitro and in vivo with VP3-truncated infectious virus. Quantitative PCR was used to detect viral replication in MDCC-MSB1 cells, and the viral localization was observed by confocal microscopy. Flow cytometry was uesed to analyze virus-induced apoptosis in MDCC-MSB1 cells. Additionally, chickens infected with the rescued viruses compared with the parental virus rM9905 to evaluate the viral replication in vivo and virulence. RESULTS: Based on the infectious clone, we rescued two viruses in which were deleted NES-NLS2 (rCAV-VP3N88) or NLS1-NES-NLS2 (rCAV-VP3N80) in the C-terminal region of apoptin. The viral load of rCAV-VP3N88 decreased significantly between 60 and 108 hpi, and was always 10-100-fold lower than that of the parental virus rM9905. The levels of rCAV-VP3N80 were also 10-100-fold lower than that of rM9905 and declined significantly at three time points. There was almost no difference in the viral loads of rCAV-VP3N88 and rCAV-VP3N80. Additionally, rM9905 induced 85.39 ± 2.18% apoptosis at 96 hpi, whereas rCAV-VP3N88 and rCAV-VP3N80 induced 63.08 ± 4.78% and 62.56 ± 7.35% apoptosis, respectively, which were significantly (about 20%) lower than that induced by the parental virus. The rescued viruses altered the nuclear localization in MDCC-MSB1 cells. Moreover, deletion of C-terminal region of apoptin impaired viral replication in vivo and reduced the virulence of CAV in chickens. CONCLUSIONS: In summary, we have demonstrated that the C-terminal deletion of apoptin in infectious CAV affected the replication of the virus. The deletion of the C-terminal region of apoptin not only significantly reduced viral replication in vitro but also reduced its induction of apoptosis, which correlated with the loss of its nuclear localization. The deletion of the C-terminal region of apoptin also impaired the replication of CAV and attenuated its virulence in chickens.


Assuntos
Apoptose , Proteínas do Capsídeo/genética , Vírus da Anemia da Galinha/fisiologia , Vírus da Anemia da Galinha/patogenicidade , Fatores de Virulência/genética , Replicação Viral , Transporte Ativo do Núcleo Celular , Animais , Proteínas do Capsídeo/metabolismo , Linhagem Celular , Galinhas , Análise Mutacional de DNA , Citometria de Fluxo , Microscopia Confocal , Reação em Cadeia da Polimerase em Tempo Real , Virulência , Fatores de Virulência/metabolismo
16.
Fish Physiol Biochem ; 43(2): 361-371, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27638477

RESUMO

An 8-week feeding trial was conducted to evaluate the effects of dietary supplementation with green tea waste (GTW) on growth, digestive enzyme and lipid metabolism of juvenile hybrid tilapia, Oreochromis niloticus × O. aureus. The fish (initial mean body weight, 12.63 ± 0.75 g) were fed five experimental diets that included 0 (control), 0.8, 1.6, 3.2 or 6.4 % of GTW in triplicate aquaria, twice daily. Growth performance, plasma metabolites content and liver and intestine digestive enzyme activities were determined. Fish accepted well all experimental diets during the trial, and no mortality was observed. The weight gain increased (P < 0.05) with the increase in GTW inclusion level up to 1.6 %, after which it decreased, but no significant differences between the control and high level (3.2 or 6.4 % of GTW) groups were observed. Moreover, fish fed on diets containing 0.8 and 1.6 % GTW had lower feed conversion ratio (FCR, 1.75 and 1.73, respectively) and had better protein deposition (higher protein efficiency ratio, PER, 1.73 and 1.71, respectively), compared to other treatments. No differences among groups were observed in whole body and dorsal muscle composition with the exception of lipid content which was lower in fish fed 6.4 % GTW diets, compared to other treatments. Lipase activities in liver or intestine were higher in fish fed GTW-supplemented diets with the exception of intestine lipase activities, which was unaffected, compared to the control. Similarly, liver lipoprotein lipase activities were also increased in fish fed diets supplemented a medium dose of GTW (1.6 or 3.2 %), compared to other treatments. However, intestine amylase activities were decreased in fish fed diets containing a high dose of GTW (3.2 and 6.4 %); while the liver amylase activities were unaffected by the GTW supplementation. Blood chemistry parameters were affected by GTW inclusion, except the values of triglycerides, which was unaffected. The values of total cholesterol, HDL cholesterol and LDL cholesterol increased with increasing GTW inclusion level up to 3.2 %, after which the values decreased. These results indicate that diets supplemented with appropriate concentration of GTW (from 0.8 to 1.6 %) may potentially serve as an effective functional food and additive for tilapia to improve growth performance, digestion efficacy and fat metabolism.


Assuntos
Suplementos Nutricionais , Chá , Tilápia , Resíduos , Amilases/metabolismo , Animais , Peso Corporal , Digestão , Mucosa Intestinal/metabolismo , Lipase/metabolismo , Metabolismo dos Lipídeos , Fígado/metabolismo , Tilápia/crescimento & desenvolvimento , Tilápia/metabolismo
17.
Zhonghua Jie He He Hu Xi Za Zhi ; 39(3): 177-82, 2016 Mar.
Artigo em Zh | MEDLINE | ID: mdl-26980530

RESUMO

OBJECTIVE: To assess the effectiveness and safety of bronchial thermoplasty (BT) in patients with severe asthma. METHOD: The China-Japan Friendship Hospital recruited 12 patients with severe asthma who were voluntary to take BT treatment from March 2014 to November 2014. The levels of airway inflammation and biological markers (percentage of blood eosinophils, percentage of sputum eosinophils, serum IgE, fractional exhaled nitric oxide) of the patients were examined before the treatment in order to identify the types of airway inflammation. The numbers of severe exacerbations and related hospitalizations within 1 year before and after BT were obtained for each patient. The occurrence of adverse events within 3 weeks after the treatment was collected. And the patient status within 1 year after the BT treatment was compared with that before the treatment, in terms of the number of severe exacerbations, exacerbation rate, the number of related hospitalizations, hospitalization rate and oral corticosteroid dose. RESULTS: For before and 1 year after the treatment, the numbers of subjects suffering severe exacerbations were 11 and 6, the numbers of total severe exacerbation were 76 and 16, the numbers of patients hospitalized due to acute attacks were 10 and 3, and the numbers of total hospitalizations were 56 and 6, respectively. The severe exacerbation rate, hospitalization rate and oral corticosteroid dose were significantly reduced 1 year after the treatment [(1.3±0.48 vs. 6.3±1.9) events/subject/year, (0.50±0.26 vs. 4.67±1.90) events/subject/year, (8.5±4.6 vs. 22.0±2.6) mg/d, P<0.05]. The most common adverse events within 3 weeks after BT treatment were cough (8 events), expectoration (20 events), temporary PEF reduction (7 events), wheezing (4 events), but most of these symptoms were relieved in 1 week. One subject suffered pneumonia after each of the 3 procedures but also recovered soon after an antibiotic therapy. No adverse events occurred because of BT treatment within 3 weeks after the treatment. Computed tomographic scans from baseline to 1 year after the BT treatment showed no structural abnormalities related to BT. CONCLUSIONS: These data demonstrate the benefits of BT with regard to both asthma control (based on reduction in severe exacerbations and hospitalizations due to acute exacerbations) and safety. BT might offer a new approach to treating severe asthma.


Assuntos
Asma/terapia , Broncoscopia , Corticosteroides , Biomarcadores/análise , Eosinófilos , Hospitalização , Humanos , Imunoglobulina E/sangue , Contagem de Leucócitos , Sons Respiratórios , Escarro/citologia
18.
Arch Virol ; 160(3): 845-9, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25577165

RESUMO

To assess the status of avian leukosis virus subgroup J (ALV-J) infection in passerine birds in China, 365 passerine birds collected from northeast China from 2011 to 2013 were tested, and two ALV-J strains were isolated from yellow-browed warbler and marsh tit. The 3'untranslated regions (3'UTRs) of the two strains were amplified, cloned, and sequenced, with the results showing that the 3'UTRs of the two strains contained multiple mutations and deletions, which are similar to viral strains isolated from Chinese layer chickens. These results demonstrate the presence of ALV-J in passerine birds and reveal the molecular characteristics of the 3'UTRs of ALV-J from passerine birds.


Assuntos
Regiões 3' não Traduzidas , Vírus da Leucose Aviária/genética , Doenças das Aves/virologia , Passeriformes/virologia , Animais , Vírus da Leucose Aviária/isolamento & purificação , Aves , China , Clonagem Molecular , Análise por Conglomerados , Genótipo , Dados de Sequência Molecular , Filogenia , Mutação Puntual , RNA Viral/genética , Análise de Sequência de DNA , Deleção de Sequência , Homologia de Sequência
19.
BMC Plant Biol ; 14: 327, 2014 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-25432517

RESUMO

BACKGROUND: To accelerate the application of the CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/ CRISPR-associated protein 9) system to a variety of plant species, a toolkit with additional plant selectable markers, more gRNA modules, and easier methods for the assembly of one or more gRNA expression cassettes is required. RESULTS: We developed a CRISPR/Cas9 binary vector set based on the pGreen or pCAMBIA backbone, as well as a gRNA (guide RNA) module vector set, as a toolkit for multiplex genome editing in plants. This toolkit requires no restriction enzymes besides BsaI to generate final constructs harboring maize-codon optimized Cas9 and one or more gRNAs with high efficiency in as little as one cloning step. The toolkit was validated using maize protoplasts, transgenic maize lines, and transgenic Arabidopsis lines and was shown to exhibit high efficiency and specificity. More importantly, using this toolkit, targeted mutations of three Arabidopsis genes were detected in transgenic seedlings of the T1 generation. Moreover, the multiple-gene mutations could be inherited by the next generation. CONCLUSIONS: We developed a toolkit that facilitates transient or stable expression of the CRISPR/Cas9 system in a variety of plant species, which will facilitate plant research, as it enables high efficiency generation of mutants bearing multiple gene mutations.


Assuntos
Arabidopsis/genética , Sistemas CRISPR-Cas/genética , Engenharia Genética/métodos , Genoma de Planta , Zea mays/genética , Agrobacterium/genética , Sequência de Bases , Vetores Genéticos/genética , Plantas Geneticamente Modificadas/genética , Protoplastos/metabolismo , Alinhamento de Sequência
20.
Virus Genes ; 49(2): 250-8, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24854142

RESUMO

The J-subgroup avian leukosis virus (ALV-J) strain WB11098J was isolated from a wild Eurasian teal, and its proviral genomic sequences were determined. The complete proviral sequence of WB11098J was 7868 nt long. WB11098J was 95.3.9 % identical to the prototype strain HPRS-103, 94.2 % identical to the American strain ADOL-7501, 94.5-94.7 % identical to Chinese broiler isolates, 94.8-97.5 % identical to layer chicken isolates, and 94.4-95.0 % identical to Chinese local chicken isolates at the nucleotide level. Phylogenetic analysis showed that the WB11098J isolate shared the greatest homology with the layer strain SD09DP03 and was included in the same cluster. Interestingly, two 19-bp insertions in the U3 regions of the 5'LTR and 5'UTR that were most likely derived from other retroviruses were found in the WB11098J isolate. These insertions separately introduced one E2BP-binding site in the U3 region of the 5'LTR and a RNA polymerase II transcription factor IIB and core promoter motif of ten elements in the 5'UTR. A 5-bp deletion was identified in the U3 region of the 5'LTR. No nucleotides were deleted in the rTM or DR-1 regions in the 3'UTR. A 1-bp deletion was detected in the E element and introduced a specific and distinct binding site for c-Ets-1. Our study is the first to report the molecular characteristics of the complete genome of an ALV-J that was isolated from a wild bird and will provide necessary information for further understanding of the evolution of ALV-J.


Assuntos
Anseriformes/virologia , Vírus da Leucose Aviária/classificação , Vírus da Leucose Aviária/isolamento & purificação , DNA Viral/genética , Genoma Viral , Análise de Sequência de DNA , Animais , Vírus da Leucose Aviária/genética , China , Análise por Conglomerados , DNA Viral/química , Genótipo , Dados de Sequência Molecular , Filogenia , Provírus/classificação , Provírus/genética , Provírus/isolamento & purificação , Homologia de Sequência
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA