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Emerging evidence indicates that fatty acid (FA) metabolic pathways regulate host immunity to vertebrate viruses. However, information on FA signaling in plant virus infection remains elusive. In this study, we demonstrate the importance of fatty acid desaturase (FAD), an enzyme that catalyzes the rate-limiting step in the conversion of saturated FAs into unsaturated FAs, during infection by a plant RNA virus. We previously found that the rare Kua-ubiquitin conjugating enzyme (Kua-UEV1) fusion protein FAD4 from Nicotiana benthamiana (NbFAD4) was down-regulated upon turnip mosaic virus (TuMV) infection. We now demonstrate that NbFAD4 is unstable and is degraded as TuMV infection progresses. NbFAD4 is required for TuMV replication, as it interacts with TuMV replication protein 6K2 and colocalizes with viral replication complexes. Moreover, NbFAD4 overexpression dampened the accumulation of immunity-related phytohormones and FA metabolites, and its catalytic activity appears to be crucial for TuMV infection. Finally, a yeast two-hybrid library screen identified the vacuolar H+-ATPase component ATP6V0C as involved in NbFAD4 degradation and further suppression of TuMV infection. This study reveals the intricate role of FAD4 in plant virus infection, and shed lights on a new mechanism by which a V-ATPase is involved in plant antiviral defense.
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Accumulated experimental evidence has shown that viruses recruit the host intracellular machinery to establish infection. It has recently been shown that the potyvirus Turnip mosaic virus (TuMV) transits through the late endosome (LE) for viral genome replication, but it is still largely unknown how the viral replication vesicles labelled by the TuMV membrane protein 6K2 target LE. To further understand the underlying mechanism, we studied the involvement of the vacuolar sorting receptor (VSR) family proteins from Arabidopsis in this process. We now report the identification of VSR4 as a new host factor required for TuMV infection. VSR4 interacted specifically with TuMV 6K2 and was required for targeting of 6K2 to enlarged LE. Following overexpression of VSR4 or its recycling-defective mutant that accumulates in the early endosome (EE), 6K2 did not employ the conventional VSR-mediated EE to LE pathway, but targeted enlarged LE directly from cis-Golgi and viral replication was enhanced. In addition, VSR4 can be N-glycosylated and this is required for its stability and for monitoring 6K2 trafficking to enlarged LE. A non-glycosylated VSR4 mutant enhanced the dissociation of 6K2 from cis-Golgi, leading to the formation of punctate bodies that targeted enlarged LE and to more robust viral replication than with glycosylated VSR4. Finally, TuMV hijacks N-glycosylated VSR4 and protects VSR4 from degradation via the autophagy pathway to assist infection. Taken together, our results have identified a host factor VSR4 required for viral replication vesicles to target endosomes for optimal viral infection and shed new light on the role of N-glycosylation of a host factor in regulating viral infection.
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Endosomas/metabolismo , Interacciones Huésped-Patógeno/fisiología , Potyvirus/patogenicidad , Proteínas de Transporte Vesicular/metabolismo , Compartimentos de Replicación Viral/metabolismo , Humanos , Enfermedades de las Plantas/microbiología , Replicación Viral/fisiologíaRESUMEN
Autophagy is induced by viral infection and has antiviral functions in plants, but the underlying mechanism is poorly understood. We previously identified a viral small interfering RNA (vsiRNA) derived from rice stripe virus (RSV) RNA4 that contributes to the leaf-twisting and stunting symptoms caused by this virus by targeting the host eukaryotic translation initiation factor 4A (eIF4A) mRNA for silencing. In addition, autophagy plays antiviral roles by degrading RSV p3 protein, a suppressor of RNA silencing. Here, we demonstrate that eIF4A acts as a negative regulator of autophagy in Nicotiana benthamiana. Silencing of NbeIF4A activated autophagy and inhibited RSV infection by facilitating autophagic degradation of p3. Further analysis showed that NbeIF4A interacts with NbATG5 and interferes with its interaction with ATG12. Overexpression of NbeIF4A suppressed NbATG5-activated autophagy. Moreover, expression of vsiRNA-4A, which targets NbeIF4A mRNA for cleavage, induced autophagy by silencing NbeIF4A. Finally, we demonstrate that eIF4A from rice, the natural host of RSV, also interacts with OsATG5 and suppresses OsATG5-activated autophagy, pointing to the conserved function of eIF4A as a negative regulator of antiviral autophagy. Taken together, these results reveal that eIF4A negatively regulates antiviral autophagy by interacting with ATG5 and that its mRNA is recognized by a virus-derived siRNA, resulting in its silencing, which induces autophagy against viral infection.
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Proteína 5 Relacionada con la Autofagia/metabolismo , Autofagia/fisiología , Factores Eucarióticos de Iniciación/metabolismo , Inmunidad de la Planta/fisiología , ARN Interferente Pequeño/metabolismo , Proteínas de Plantas/metabolismo , Tenuivirus , Nicotiana/virologíaRESUMEN
Double-stranded RNA (dsRNA) is associated with most viral infections, and is generated in host cells during viral replication. Viral RNA replication occurs within the viral factories called the viral replication complexes (VRCs). In addition to viral genome, viral-derived dsRNA and replicase, the VRCs composition remains largely unexplored. The dsRNA binding domain of the B2 protein from Flock house virus has been reported to be used for detecting viral-derived long dsRNA in plants efficiently. Nicotiana benthamiana is widely used as a model plant for plant-microbe interactions owing to its susceptibility to diverse plant diseases, especially viral diseases. Here, we describe the use of Nicotiana benthamiana stably expressing GFP-tagged dsRNA binding protein (B2: GFP) to pull down dsRNA and associated host and viral proteins from turnip mosaic virus-infected plants. The obtained protein complexes are compatible with functional assays, Western blotting, and mass spectrometry. This system provides a valuable and robust tool to study VRC proteome in N. benthamiana upon plant viral infections.
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Nicotiana , Virosis , Nicotiana/genética , ARN Bicatenario/genética , Bioensayo , InmunoprecipitaciónRESUMEN
An important cellular barrier to maintain the stability of the brain's internal and external environment is the blood-brain barrier (BBB). It also prevents harmful substances from entering brain tissue through blood circulation while providing protection for the central nervous system. It should be noted, however, that the intact BBB can be a barrier to the transport of most drugs into the brain via the conventional route of administration, which can prevent them from reaching effective concentrations for the treatment of disorders affecting the central nervous system. Electroacupuncture stimulation has been shown to be effective at opening the BBB in a series of experimental studies. This study systematically analyzes the possibility and mechanism by which electroacupuncture opens the BBB. In PubMed, Web of Science, VIP Database, Wanfang Database, and the Chinese National Knowledge Infrastructure, papers have been published for nearly 22 years aimed at opening the BBB and its associated structures. A comparison of EB content between electroacupuncture and control was selected as the primary outcome. There were also results on vascular endothelial growth factor (VEGF), nerve growth factor (NGF), P-Glycoprotein (P-gp), Matrix Metalloproteinase 9 (MMP-9), and glial fibrillary acidic protein (GFAP). We utilized Review Manager software analysis to analyze correlations between studies with a view to exploring the mechanisms of similarity. Evans Blue infiltration forest plot: pooled effect size of 2.04, 95% CI: 1.21 to 2.87, P < 0.01. These results indicate that electroacupuncture significantly increases EB penetration across the BBB. Most studies have reported that GFAP, MMP-9, and VEGF were upregulated after treatment. P-gp expression decreased as well. Electroacupuncture can open the BBB, and the sparse-dense wave is currently the most effective electroacupuncture frequency for opening the BBB. VEGF plays an important role in opening the BBB. It is also important to regulate the expression of MMP-9 and GFAP and inhibit the expression of P-gp.
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Barrera Hematoencefálica , Electroacupuntura , Ratas , Animales , Barrera Hematoencefálica/metabolismo , Factor A de Crecimiento Endotelial Vascular/metabolismo , Metaloproteinasa 9 de la Matriz/metabolismo , Ratas Sprague-Dawley , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Subfamilia B de Transportador de Casetes de Unión a ATP/metabolismo , PermeabilidadRESUMEN
INTRODUCTION: Paclitaxel (PTX) cannot effectively treat glioma because it cannot cross the bloodbrain barrier (BBB). A specific mode electroacupuncture stimulation (SMES) can temporarily open the BBB, thereby improving drug delivery to the brain. This study aimed to observe SMES-mediated accumulation of PTX in the brain and its anti-glioma effect and explore the role of the Hedgehog pathway. METHODS: The acupoint selectivity of SMES in opening the BBB was examined in normal rats. The penetration and anti-glioma activity were determined in a C6-Luc glioma rat model. SMES was performed using 2/100â¯Hz, 3â¯mA, 6-6â¯s, and 40â¯min The survival curve was analysed by the KaplanMeier method, brain tumour pathology and size was observed by HE staining, and in vivo imaging system respectively. RESULTS: SMES-induced BBB opening had acupoint selectivity. SMES could improve PTX accumulation in brain and SMES-mediated PTX delivery showed enhanced anti-glioma activity due to better brain penetration. Hedgehog pathway was involved in SMES-mediated PTX delivery by regulating Occludin expression. CONCLUSION: SMES at the head acupoints to deliver PTX is a feasible and effective method for treating glioma. The Hedgehog pathway may play a key role in SMES-mediated PTX delivery across the BBB.
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Antineoplásicos Fitogénicos , Barrera Hematoencefálica , Neoplasias Encefálicas , Electroacupuntura , Glioma , Proteínas Hedgehog , Paclitaxel , Animales , Electroacupuntura/métodos , Paclitaxel/farmacología , Proteínas Hedgehog/metabolismo , Glioma/terapia , Glioma/metabolismo , Neoplasias Encefálicas/terapia , Neoplasias Encefálicas/metabolismo , Antineoplásicos Fitogénicos/farmacología , Barrera Hematoencefálica/efectos de los fármacos , Barrera Hematoencefálica/metabolismo , Masculino , Ratas , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiología , Ratas Sprague-Dawley , Línea Celular Tumoral , Encéfalo/metabolismo , Encéfalo/efectos de los fármacosRESUMEN
Cognitive impairment frequently presents as a prevalent consequence following stroke, imposing significant burdens on patients, families, and society. The objective of this study was to assess the effectiveness and underlying mechanism of nerve growth factor (NGF) in treating post-stroke cognitive dysfunction in rats with cerebral ischemia-reperfusion injury (MCAO/R) through delivery into the brain using specific mode electroacupuncture stimulation (SMES). From the 28th day after modeling, the rats were treated with NGF mediated by SMES, and the cognitive function of the rats was observed after treatment. Learning and memory ability were evaluated using behavioral tests. The impact of SMES on blood-brain barrier (BBB) permeability, the underlying mechanism of cognitive enhancement in rats with MCAO/R, including transmission electron microscopy, enzyme-linked immunosorbent assay, immunohistochemistry, immunofluorescence, and TUNEL staining. We reported that SMES demonstrates a safe and efficient ability to open the BBB during the cerebral ischemia repair phase, facilitating the delivery of NGF to the brain by the p65-VEGFA-TJs pathway.
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BACKGROUND: The emergence of the Nerve Growth Factor (NGF) has promoted the development of neuroprotective therapy; however, it has little effect on cerebral ischemia because of its poor Blood-Brain Barrier (BBB) permeability. Specific Mode Electroacupuncture Stimulation (SMES) can open BBB safely and effectively; however, it has shown inconclusive clinical effects and indirect clinical evidence in the recovery phase. Hence, the authors conducted a multicentre, randomized, placebo-controlled, assessor-blinded clinical trial to assess the effectiveness and safety of SMES combined with NGF treatment used during ischaemic stroke recovery. METHODS: A total of 288 stroke patients from three hospitals will be recruited and randomly allocated to four groups: acupuncture + placebo, acupuncture + NGF, SMES + placebo, and SMES + NGF, in a 1:1:1:1 ratio. Assessment data will be collected at baseline, 2-weeks, and 4-weeks during the treatment period, as well as at the 4-week and 8-week follow-up after treatment completion. The primary outcome measure will be the basic cure rate. The secondary outcome measures include the simplified Modified Barthel Index, Timed Up and Go Test, Fugl-Meyer Assessment of Motor Function Score, Tinetti Performance Oriented Mobility Assessment, Montreal Cognitive Assessment, and Loewenstein Occupational Therapy Cognitive Assessment. Moreover, resting-state functional magnetic resonance imaging and Functional near-infrared spectroscopy can detect changes in cerebral blood flow and brain function and investigate the relationship between the clinical efficacy and mechanism of the prescribed interventions. CONCLUSION: This study will provide clinical evidence for the efficacy and safety of SMES combined with NGF in the treatment of stroke patients.
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Electroacupuntura , Accidente Cerebrovascular Isquémico , Factor de Crecimiento Nervioso , Humanos , Electroacupuntura/métodos , Accidente Cerebrovascular Isquémico/terapia , Resultado del Tratamiento , Terapia Combinada , Masculino , Femenino , Persona de Mediana Edad , Ensayos Clínicos Controlados Aleatorios como Asunto , AdultoRESUMEN
Viruses encounter numerous host factors that facilitate or suppress viral infection. Although some host factors manipulated by viruses were uncovered, we have limited knowledge of the pathways hijacked to promote viral replication and activate host defense responses. Turnip mosaic virus (TuMV) is one of the most prevalent viral pathogens in many regions of the world. Here, we employed an isobaric tag for relative and absolute quantitation (iTRAQ)-based proteomics approach to characterize cellular protein changes in the early stages of infection of Nicotiana benthamiana by wild type and replication-defective TuMV. A total of 225 differentially accumulated proteins (DAPs) were identified (182 increased and 43 decreased). Bioinformatics analysis showed that a few biological pathways were associated with TuMV infection. Four upregulated DAPs belonging to uridine diphosphate-glycosyltransferase (UGT) family members were validated by their mRNA expression profiles and their effects on TuMV infection. NbUGT91C1 or NbUGT74F1 knockdown impaired TuMV replication and increased reactive oxygen species production, whereas overexpression of either promoted TuMV replication. Overall, this comparative proteomics analysis delineates the cellular protein changes during early TuMV infection and provides new insights into the role of UGTs in the context of plant viral infection.
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Nicotiana , Potyvirus , Proteómica , Potyvirus/genética , Enfermedades de las PlantasRESUMEN
Chloroplast clustering around the nucleus is a well-known mechanism that occurs in response to various biotic and abiotic stresses and is believed to be a mechanism of defence against pathogens in plants. This phenomenon is accompanied by increased production of reactive oxygen species (ROS), which can help to destroy invading pathogens. However, the function of chloroplast clustering during viroid infection is unclear. Here, we report that, although the infection by potato spindle tuber viroid (PSTVd) failed to induce chloroplast clustering, chloroplast clustering caused by the overexpression of the Nicotiana benthamiana chloroplast outer membrane protein 24 (NbOMP24) promoted the infection by PSTVd, a viroid pathogen, in N. benthamiana. Interestingly, H2 O2 treatment, which caused increased ROS accumulation, showed no significant effects on PSTVd infection. Moreover, NbOMP24 protein showed no direct interaction with PSTVd. We propose that perinuclear chloroplast clustering induced by NbOMP24 provides a favourable environment for PSTVd infection. These findings highlight the complexity of chloroplast clustering-mediated plant-pathogen interactions and the need for further research to fully understand these mechanisms.
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Nicotiana , Viroides , Nicotiana/genética , Nicotiana/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Viroides/genética , ARN Viral/metabolismo , Enfermedades de las PlantasRESUMEN
Pepper mild mottle virus (PMMoV) is a devastating viral pathogen of pepper (Capsicum annuum) but it is unclear whether and how peppers protect against PMMoV infection. The expression of the chloroplast outer membrane protein 24 (OMP24) of C. annuum was upregulated under PMMoV infection and it interacted with PMMoV coat protein (CP). Silencing of OMP24 in either C. annuum or Nicotiana benthamiana facilitated PMMoV infection, whereas overexpression of N. benthamiana OMP24 in transgenic plants inhibited PMMoV infection. Both C. annuum OMP24 (CaOMP24) and N. benthamiana OMP24 (NbOMP24) localized to the chloroplast and have a moderately hydrophobic transmembrane domain that is necessary for their localization. Overexpression of CaOMP24 induced stromules, perinuclear chloroplast clustering, and accumulation of reactive oxygen species (ROS), the typical defense responses of chloroplasts transferring the retrograde signaling to the nucleus to regulate resistance genes. The expression of PR1 and PR2 was also upregulated significantly in plants overexpressing OMP24. Self-interaction of OMP24 was demonstrated and was required for OMP24-mediated plant defense. Interaction with PMMoV CP interfered with the self-interaction of OMP24 and impaired OMP24-induced stromules, perinuclear chloroplast clustering and ROS accumulation. The results demonstrate the defense function of OMP24 in pepper during viral infection and suggest a possible mechanism by which PMMoV CP modulates the plant defense to facilitate viral infection.
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INTRODUCTION: Cancer-related insomnia (CRI), as a common complication in cancer survivors, may further lead to depression, anxiety and other symptoms. Acupuncture therapy is a promising therapeutic strategy for CRI. The effectiveness of acupuncture therapy on CRI has been validated by several relevant meta-analyses. Questions remain, however, including which acupuncture regimen is optimal. We aim to conduct the first network meta-analysis to compare different acupuncture therapies, rank their effectiveness and assess which approach could be optimal for treatment of CRI. METHODS AND ANALYSIS: A comprehensive search of PubMed, Cochrane Library, Web of Science, Embase, China National Knowledge Infrastructure, Wanfang Database, VIP Database (China Science and Technology Journal Database), and China Biology Medicine (from inception until 1 March 2022) will be carried out to identify randomised controlled trials (RCTs) of acupuncture therapy for insomnia in cancer survivors, reported in English or Chinese. Reviews, animal studies, non-RCT studies, editorials and other secondary insomnia studies will be excluded. The primary outcome measure will be the Pittsburgh Sleep Quality Index. Pairwise meta-analysis will be performed in Stata and network meta-analysis by OpenBUGS, R and Stata. Network plots and funnel plots will be used to show the scale of studies and participants for each intervention and the potential publication bias, respectively. Both heterogeneity and consistency will be evaluated by R. ORs with 95% CIs and mean differences with 95% CI will be calculated in OpenBUGS and transformed into league figure and surface under the cumulative ranking by Stata to visualise the results. ETHICS AND DISSEMINATION: Ethical committee approval for this review is unnecessary since the data used will be extracted from pre-existing literature. The results will be submitted for publication in a peer-reviewed journal and presented at international academic conferences.
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Terapia por Acupuntura , Neoplasias , Trastornos del Inicio y del Mantenimiento del Sueño , Humanos , Trastornos del Inicio y del Mantenimiento del Sueño/etiología , Trastornos del Inicio y del Mantenimiento del Sueño/terapia , Metaanálisis en Red , Neoplasias/complicaciones , Neoplasias/terapia , Terapia por Acupuntura/métodos , Trastornos de Ansiedad , Proyectos de Investigación , Metaanálisis como Asunto , Literatura de Revisión como AsuntoRESUMEN
Previously we reported that the multifunctional cylindrical inclusion (CI) protein of turnip mosaic virus (TuMV) is targeted to endosomes through the interaction with the medium subunit of adaptor protein complex 2 (AP2ß), which is essential for viral infection. Although several functionally important regions in the CI have been identified, little is known about the determinant(s) for endosomal trafficking. The CI protein contains seven conserved acidic dileucine motifs [(D/E)XXXL(L/I)] typical of endocytic sorting signals recognized by AP2ß. Here, we selected five motifs for further study and identified that they all were located in the regions of CI interacting with AP2ß. Coimmunoprecipitation assays revealed that alanine substitutions in the each of these acidic dileucine motifs decreased binding with AP2ß. Moreover, these CI mutants also showed decreased accumulation of punctate bodies, which enter endocytic-tracking styryl-stained endosomes. The mutations were then introduced into a full-length infectious clone of TuMV, and each mutant had reduced viral replication and systemic infection. The data suggest that the acidic dileucine motifs in CI are indispensable for interacting with AP2ß for efficient viral replication. This study provides new insights into the role of endocytic sorting motifs in the intracellular movement of viral proteins for replication.