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Receptor clustering on the cell membrane is critical in the signaling of many immunoreceptors, and this mechanism has previously been attributed to the extracellular and/or the intracellular interactions. Here, we report an unexpected finding that for death receptor 5 (DR5), a receptor in the tumor necrosis factor receptor superfamily, the transmembrane helix (TMH) alone in the receptor directly assembles a higher-order structure to drive signaling and that this structure is inhibited by the unliganded ectodomain. Nuclear magnetic resonance structure of the TMH in bicelles shows distinct trimerization and dimerization faces, allowing formation of dimer-trimer interaction networks. Single-TMH mutations that disrupt either trimerization or dimerization abolish ligand-induced receptor activation. Surprisingly, proteolytic removal of the DR5 ectodomain can fully activate downstream signaling in the absence of ligand. Our data suggest a receptor activation mechanism in which binding of ligand or antibodies to overcome the pre-ligand autoinhibition allows TMH clustering and thus signaling.
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Receptores del Ligando Inductor de Apoptosis Relacionado con TNF/metabolismo , Apoptosis , Línea Celular Tumoral , Membrana Celular/metabolismo , Células HEK293 , Humanos , Ligandos , Modelos Moleculares , Mutagénesis Sitio-Dirigida/métodos , Unión Proteica , Proteolisis , Receptores Citoplasmáticos y Nucleares/metabolismo , Receptores del Ligando Inductor de Apoptosis Relacionado con TNF/química , Receptores del Ligando Inductor de Apoptosis Relacionado con TNF/ultraestructura , Transducción de SeñalRESUMEN
The vaccine strain against smallpox, vaccinia virus (VACV), is highly immunogenic yet causes relatively benign disease. These attributes are believed to be caused by gene loss in VACV. Using a targeted small interfering RNA (siRNA) screen, we identified a viral inhibitor found in cowpox virus (CPXV) and other orthopoxviruses that bound to the host SKP1-Cullin1-F-box (SCF) machinery and the essential necroptosis kinase receptor interacting protein kinase 3 (RIPK3). This "viral inducer of RIPK3 degradation" (vIRD) triggered ubiquitination and proteasome-mediated degradation of RIPK3 and inhibited necroptosis. In contrast to orthopoxviruses, the distantly related leporipoxvirus myxoma virus (MYXV), which infects RIPK3-deficient hosts, lacks a functional vIRD. Introduction of vIRD into VACV, which encodes a truncated and defective vIRD, enhanced viral replication in mice. Deletion of vIRD reduced CPXV-induced inflammation, viral replication, and mortality, which were reversed in RIPK3- and MLKL-deficient mice. Hence, vIRD-RIPK3 drives pathogen-host evolution and regulates virus-induced inflammation and pathogenesis.
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Virus de la Viruela Vacuna/fisiología , Viruela Vacuna/inmunología , ARN Interferente Pequeño/genética , Proteína Serina-Treonina Quinasas de Interacción con Receptores/metabolismo , Virus Vaccinia/metabolismo , Proteínas Virales/metabolismo , Animales , Evolución Molecular , Células HEK293 , Interacciones Huésped-Patógeno , Humanos , Inflamación , Ratones , Ratones Noqueados , Necroptosis/genética , Orthopoxvirus , Filogenia , Proteínas Quinasas/genética , Proteolisis , Proteína Serina-Treonina Quinasas de Interacción con Receptores/genética , Análisis de Secuencia de ARN , Proteínas Virales/genética , Replicación ViralRESUMEN
Human mixed-lineage leukemia (MLL) family methyltransferases methylate histone H3 lysine 4 to different methylation states (me1/me2/me3) with distinct functional outputs, but the mechanism underlying the different product specificities of MLL proteins remains unclear. Here, we develop methodologies to quantitatively measure the methylation rate difference between mono-, di-, and tri-methylation steps and demonstrate that MLL proteins possess distinct product specificities in the context of the minimum MLL-RBBP5-ASH2L complex. Comparative structural analyses of MLL complexes by X-ray crystal structures, fluorine-19 nuclear magnetic resonance, and molecular dynamics simulations reveal that the dynamics of two conserved tyrosine residues at the "F/Y (phenylalanine/tyrosine) switch" positions fine-tune the product specificity. The variation in the intramolecular interaction between SET-N and SET-C affects the F/Y switch dynamics, thus determining the product specificities of MLL proteins. These results indicate a modified F/Y switch rule applicable for most SET domain methyltransferases and implicate the functional divergence of MLL proteins.
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N-Metiltransferasa de Histona-Lisina , Leucemia , Humanos , N-Metiltransferasa de Histona-Lisina/metabolismo , Histonas/metabolismo , Metiltransferasas/genética , Metiltransferasas/metabolismo , Lisina/metabolismo , Flúor/metabolismo , Proteína de la Leucemia Mieloide-Linfoide/metabolismo , Tirosina , FenilalaninaRESUMEN
Neurons regulate the microtubule-based transport of certain vesicles selectively into axons or dendrites to ensure proper polarization of function. The mechanism of this polarized vesicle transport is still not fully elucidated, though it is known to involve kinesins, which drive anterograde transport on microtubules. Here, we explore how the kinesin-3 family member KIF13A is regulated such that vesicles containing transferrin receptor (TfR) travel only to dendrites. In experiments involving live-cell imaging, knockout of KIF13A, BioID assay, we found that the kinase MARK2 phosphorylates KIF13A at a 14-3-3 binding motif, strengthening interaction of KIF13A with 14-3-3 such that it dissociates from TfR-containing vesicles, which therefore cannot enter axons. Overexpression of KIF13A or knockout of MARK2 leads to axonal transport of TfR-containing vesicles. These results suggest a unique kinesin-based mechanism for polarized transport of vesicles to dendrites.
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Proteínas 14-3-3 , Dendritas , Cinesinas , Proteínas Serina-Treonina Quinasas , Receptores de Transferrina , Cinesinas/metabolismo , Cinesinas/genética , Proteínas 14-3-3/metabolismo , Dendritas/metabolismo , Fosforilación , Receptores de Transferrina/metabolismo , Animales , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Humanos , Sitios de Unión , Microtúbulos/metabolismo , Ratas , Ratones , Unión ProteicaRESUMEN
TAK1 is a key modulator of both NF-κB signaling and RIPK1. In TNF signaling pathway, activation of TAK1 directly mediates the phosphorylation of IKK complex and RIPK1. In a search for small molecule activators of RIPK1-mediated necroptosis, we found R406/R788, two small molecule analogs that could promote sustained activation of TAK1. Treatment with R406 sensitized cells to TNF-mediated necroptosis and RIPK1-dependent apoptosis by promoting sustained RIPK1 activation. Using click chemistry and multiple biochemical binding assays, we showed that treatment with R406 promotes the activation of TAK1 by directly binding to TAK1, independent of its original target Syk kinase. Treatment with R406 promoted the ubiquitination of TAK1 and the interaction of activated TAK1 with ubiquitinated RIPK1. Finally, we showed that R406/R788 could promote the cancer-killing activities of TRAIL in vitro and in mouse models. Our studies demonstrate the possibility of developing small molecule TAK1 activators to potentiate the effect of TRAIL as anticancer therapies.
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Apoptosis , Neoplasias , Animales , Ratones , Muerte Celular , Citosol , Neoplasias/tratamiento farmacológico , Neoplasias/genética , UbiquitinaciónRESUMEN
Bax proteins form pores in the mitochondrial outer membrane to initiate apoptosis. This might involve their embedding in the cytosolic leaflet of the lipid bilayer, thus generating tension to induce a lipid pore with radially arranged lipids forming the wall. Alternatively, Bax proteins might comprise part of the pore wall. However, there is no unambiguous structural evidence for either hypothesis. Using NMR, we determined a high-resolution structure of the Bax core region, revealing a dimer with the nonpolar surface covering the lipid bilayer edge and the polar surface exposed to water. The dimer tilts from the bilayer normal, not only maximizing nonpolar interactions with lipid tails but also creating polar interactions between charged residues and lipid heads. Structure-guided mutations demonstrate the importance of both types of protein-lipid interactions in Bax pore assembly and core dimer configuration. Therefore, the Bax core dimer forms part of the proteolipid pore wall to permeabilize mitochondria.
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Mitocondrias/metabolismo , Membranas Mitocondriales/metabolismo , Proteína X Asociada a bcl-2/metabolismo , Apoptosis/fisiología , Humanos , Membrana Dobles de Lípidos/metabolismoRESUMEN
Protein allostery is commonly observed in vitro. But how protein allostery behaves in cells is unknown. In this work, a protein monomer-dimer equilibrium system was built with the allosteric effect on the binding characterized using NMR spectroscopy through mutations away from the dimer interface. A chemical shift linear fitting method was developed that enabled us to accurately determine the dissociation constant. A total of 28 allosteric mutations were prepared and grouped to negative allosteric, nonallosteric, and positive allosteric modulators. â¼ 50% of mutations displayed the allosteric-state changes when moving from a buffered solution into cells. For example, there were no positive allosteric modulators in the buffered solution but eight in cells. The change in protein allostery is correlated with the interactions between the protein and the cellular environment. These interactions presumably drive the surrounding macromolecules in cells to transiently bind to the monomer and dimer mutational sites and change the free energies of the two species differently which generate new allosteric effects. These surrounding macromolecules create a new protein allostery pathway that is only present in cells.
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Resonancia Magnética Nuclear Biomolecular , Regulación Alostérica , Mutación , Multimerización de Proteína , Modelos MolecularesRESUMEN
Five pairs of new merosesquiterpenoid enantiomers, named dauresorcinols A-E (1-5), were isolated from the leaves of Rhododendron dauricum. Their structures were elucidated by comprehensive spectroscopic data analysis, quantum chemical calculations, Rh2(OCOCF3)4-induced ECD, and single-crystal X-ray diffraction analysis. Dauresorcinols A (1) and B (2) possess two new merosesquiterpene skeletons bearing an unprecedented 2,6,7,10,14-pentamethyl-11-oxatetracyclo[8.8.0.02,7.012,17]octadecane and a caged 15-isohexyl-1,5,15-trimethyl-2,10-dioxatetracyclo[7.4.1.111,14.03,8]pentadecane motif, respectively. Plausible biosynthetic pathways of 1-5 are proposed involving key oxa-electrocyclization and Wagner-Meerwein rearrangement reactions. (+)/(-)-1 and 3-5 showed potent α-glucosidase inhibitory activity, 3 to 22 times stronger than acarbose, an antidiabetic drug targeting α-glucosidase. Docking results provide a basis to design and develop merosesquiterpenoids as potent α-glycosidase inhibitors.
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Inhibidores de Glicósido Hidrolasas , Rhododendron , Rhododendron/química , Estereoisomerismo , Inhibidores de Glicósido Hidrolasas/química , Inhibidores de Glicósido Hidrolasas/farmacología , Inhibidores de Glicósido Hidrolasas/aislamiento & purificación , Estructura Molecular , Relación Estructura-Actividad , Sesquiterpenos/química , Sesquiterpenos/farmacología , Sesquiterpenos/aislamiento & purificación , alfa-Glucosidasas/metabolismo , Simulación del Acoplamiento Molecular , Humanos , Relación Dosis-Respuesta a Droga , Hojas de la Planta/química , Cristalografía por Rayos X , Modelos MolecularesRESUMEN
BACKGROUND: Emerging evidence supports the association between periodontitis and depression, although the mechanisms are unclear. This study investigated the role of SorCS2 in the pathogenesis of periodontitis-induced depression. MATERIALS AND METHODS: An experimental periodontitis model was established using SorCS2 knockout mice and their wild-type littermates, and depression-like behaviour was evaluated. The expression of proBDNF signalling, neuronal activity, and glutamate-associated signalling pathways were further measured by western blotting and immunofluorescence. In addition, neuroinflammatory status, astrocytic and microglial markers, and the expression of corticosterone-related factors were measured by immunofluorescence, western blotting, and enzyme-linked immunosorbent assays. RESULTS: SorCS2 deficiency alleviated periodontitis-induced depression-like behaviour in mice. Further results suggested that SorCS2 deficiency downregulated the expression of pro-BDNF and glutamate signalling and restored neuronal activities in mice with periodontitis. Neuroinflammation in the mouse hippocampus was triggered by experimental periodontitis but was not affected by SorCS2 deficiency. The levels of corticosterone and the expression of glucocorticoid receptors were also not altered. CONCLUSION: Our study, for the first time, reveals the critical role of SorCS2 in the pathogenesis of periodontitis-induced depression. The underlying mechanism involves proBDNF and glutamate signalling in the hippocampus, providing a novel therapeutic target for periodontitis-associated depression.
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BACKGROUND: Screen time and physical activity behaviors undergo development during early childhood and impact mental health. However, there is limited knowledge regarding the associations between physical activity, screen time, and mental health problems (MHP) in preschoolers. This study examines these associations using a large sample size and brief measures. METHODS: A multistage cluster stratified sampling method was used to conduct an observational cross-sectional study of 19,015 Chinese preschoolers in 2020. Information on physical activity, and screen time was collected by a self-administered questionnaire; MHP was assessed by the parent-reported Strengths and Difficulties Questionnaire (SDQ). Logistic regression models were used to obtain the odds ratios (ORs) and 95% confidence intervals (95% CIs) of preschoolers' MHP associated with screen time, total physical activities, moderate to vigorous physical activity (MVPA), and outdoor physical activities. RESULTS: A total of 19,015 participants from the 19,548 recruited population were included in the analyses (missing rate: 2.73%), 52.60% were boys. 64.01%, 57.96%, 35.98%, and 82.64% of preschoolers were reported to meet total physical activities, MVPA, and outdoor activities with screen time recommendations level. The results of multivariable-adjusted ORs (95% CIs) of preschoolers' MHP for comparisons of different levels of screen time (< 2 h/day, 2-4 h/day,≥4 h/day) show that screen time positively associated with MHP after adjusting for confounders (P < 0.05), but the association was not significant among girls with screen time ≥ 4 h/day. In addition, increased engagement in physical activity was reversely linked to MHP (P < 0.05). A stronger association between MHP and MVPA was observed in boys, however, this association was weakened when the total time spent engaging in MVPA exceeded two hours per day (P < 0.05). CONCLUSION: Less physical activity and more screen time positively relate to MHP, but the relationship differs by type of physical activity, total time, and gender. These findings provide novel insights and evidence supporting for guidelines on physical activity, screen time, and improvement of mental health for preschoolers.
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Salud Mental , Tiempo de Pantalla , Preescolar , Femenino , Humanos , Masculino , China/epidemiología , Estudios Transversales , Ejercicio FísicoRESUMEN
The spread of pathological α-synuclein (α-syn) is a crucial event in the progression of Parkinson's disease (PD). Cell surface receptors such as lymphocyte activation gene 3 (LAG3) and amyloid precursor-like protein 1 (APLP1) can preferentially bind α-syn in the amyloid over monomeric state to initiate cell-to-cell transmission. However, the molecular mechanism underlying this selective binding is unknown. Here, we perform an array of biophysical experiments and reveal that LAG3 D1 and APLP1 E1 domains commonly use an alkaline surface to bind the acidic C terminus, especially residues 118 to 140, of α-syn. The formation of amyloid fibrils not only can disrupt the intramolecular interactions between the C terminus and the amyloid-forming core of α-syn but can also condense the C terminus on fibril surface, which remarkably increase the binding affinity of α-syn to the receptors. Based on this mechanism, we find that phosphorylation at serine 129 (pS129), a hallmark modification of pathological α-syn, can further enhance the interaction between α-syn fibrils and the receptors. This finding is further confirmed by the higher efficiency of pS129 fibrils in cellular internalization, seeding, and inducing PD-like α-syn pathology in transgenic mice. Our work illuminates the mechanistic understanding on the spread of pathological α-syn and provides structural information for therapeutic targeting on the interaction of α-syn fibrils and receptors as a potential treatment for PD.
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Precursor de Proteína beta-Amiloide/metabolismo , Amiloide/metabolismo , Antígenos CD/metabolismo , Enfermedad de Parkinson/metabolismo , Enfermedad de Parkinson/patología , alfa-Sinucleína/metabolismo , Animales , Línea Celular Tumoral , Endocitosis , Humanos , Ratones , Degeneración Nerviosa/patología , Neuronas/metabolismo , Fosforilación , Fosfoserina/metabolismo , Unión Proteica , Electricidad Estática , alfa-Sinucleína/química , alfa-Sinucleína/toxicidad , Proteína del Gen 3 de Activación de LinfocitosRESUMEN
A four-step synthetic process has been developed to prepare 1,3,5,8-tetrahydroxyxanthone (2a) and its isomer 1,3,7,8-tetrahydroxyxanthone (2b). 25 more xanthones were also synthesized by a modified scheme. Xanthone 2a was identified as the most active inhibitor against both α-glucosidase and aldose reductase (ALR2), with IC50 values of 7.8 ± 0.5 µM and 63.2 ± 0.6 nM, respectively, which was far active than acarbose (35.0 ± 0.1 µM), and a little more active than epalrestat (67.0 ± 3.0 nM). 2a was also confirmed as the most active antioxidant in vitro with EC50 value of 8.9 ± 0.1 µM. Any structural modification including methylation, deletion, and position change of hydroxyl group in 2a will cause an activity loss in inhibitory and antioxidation. By applying a H2 O2 -induced oxidative stress nematode model, it was confirmed that xanthone 2a can be absorbed by Caenorhabditis elegans and is bioavailable to attenuate in vivo oxidative stress, including the effects on lifespan, superoxide dismutase, Catalase, and malondialdehyde. 2a was verified with in vivo hypoglycemic effect and mitigation of embryo malformations in high glucose. All our data support that xanthone 2a behaves triple roles and is a potential agent to treat diabetic mellitus, gestational diabetes mellitus, and diabetic complications.
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Complicaciones de la Diabetes , Diabetes Mellitus , Xantonas , Humanos , Relación Estructura-Actividad , Hipoglucemiantes/farmacología , Hipoglucemiantes/uso terapéutico , Hipoglucemiantes/química , alfa-Glucosidasas/química , alfa-Glucosidasas/metabolismo , Complicaciones de la Diabetes/tratamiento farmacológico , Antioxidantes/farmacología , Antioxidantes/uso terapéutico , Xantonas/farmacología , Xantonas/uso terapéutico , Simulación del Acoplamiento Molecular , Diabetes Mellitus/tratamiento farmacológicoRESUMEN
Receptor Interacting Protein Kinase 1 (RIPK1) and RIPK3 are key adaptors that play critical roles in inflammatory and cell death signaling. Work in recent years have shown that their activities are tightly regulated by ubiquitination, phosphorylation and proteolysis. In addition to these post-translational modifications, the expression and activities of these kinases can further be tuned by environmental changes in pH and oxygen content. Proper control of these regulatory processes is crucial for the RIP kinases to execute their functions in immune responses and tissue homeostasis. In this review, we discuss recent advance in our understanding of the molecular mechanisms that regulate the activities of the RIP kinases. We will also discuss how the different regulatory mechanisms contribute to the functions of RIPK1 and RIPK3 in different pathophysiological settings.
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Muerte Celular/inmunología , Inflamación/inmunología , Proteína Serina-Treonina Quinasas de Interacción con Receptores/metabolismo , HumanosRESUMEN
BACKGROUND: Exosomes (Exos) can safely and effectively deliver therapeutic substances to glioma cells; however, their blood-brain barrier (BBB) crossing capacity remains limited. Focused ultrasound (FUS) can transiently, reversibly, and locally open the BBB, while the effects of FUS combined with Exos-miRNA on the treatment of glioma have not been explored to date. METHODS: Exos were extracted by differential centrifugation and the efficacy of miR-1208-loaded Exos combined with FUS in the treatment of glioma was detected by CCK-8, colony formation, flow cytometry, transwell and tumour xenografts assays. The METTL3-mediated regulation of IGF2BP2 on mRNA stability of NUP214 was determined by MeRIP-qPCR, half-life and RIP assays. RESULTS: We used Exos secreted by mesenchymal stem cells as carriers for the tumour suppressor gene miR-1208, and following FUS irradiation, more Exos carrying miR-1208 were allowed to pass through the BBB, and the uptake of miR-1208 in Exos by glioma cells was promoted, thereby achieving high-efficiency tumour-suppressive effects. Furthermore, the molecular mechanism underlying this effect was elucidated that miR-1208 downregulated the m6A methylation level of NUP214 mRNA by negatively regulating the expression of METTL3, thereby NUP214 expression and TGF-ß pathway activity were suppressed. CONCLUSIONS: MiR-1208-loaded Exos combined with FUS is expected to become an effective glioma treatment and deserves further clinical evaluation.
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Exosomas , Glioma , Células Madre Mesenquimatosas , MicroARNs , Humanos , Barrera Hematoencefálica/metabolismo , Exosomas/metabolismo , Glioma/genética , Glioma/terapia , Glioma/metabolismo , Células Madre Mesenquimatosas/metabolismo , Metiltransferasas , MicroARNs/genética , MicroARNs/metabolismo , Proteínas de Unión al ARN/metabolismoRESUMEN
Reversible solid oxide cells based on proton conductors (P-ReSOCs) have potential to be the most efficient and low-cost option for large-scale energy storage and power generation, holding promise as an enabler for the implementation of intermittent renewable energy technologies and the widespread utilization of hydrogen. Here, the rational design of a new class of hexavalent Mo/W-doped proton-conducting electrolytes with excellent durability while maintaining high conductivity is reported. Specifically, BaMo(W)0.03 Ce0.71 Yb0.26 O3-δ exhibits dramatically enhanced chemical stability against high concentrations of steam and carbon dioxide than the state-of-the-art electrolyte materials while retaining similar ionic conductivity. In addition, P-ReSOCs based on BaW0.03 Ce0.71 Yb0.26 O3-δ demonstrate high peak power densities of 1.54, 1.03, 0.72, and 0.48 W cm-2 at 650, 600, 550, and 500 °C, respectively, in the fuel cell mode. During steam electrolysis, a high current density of 2.28 A cm-2 is achieved at a cell voltage of 1.3 V at 600 °C, and the electrolysis cell can operate stably with no noticeable degradation when exposed to high humidity of 30% H2 O at -0.5 A cm-2 and 600 °C for over 300 h. Overall, this work demonstrates the promise of donor doping for obtaining proton conductors with both high conductivity and chemical stability for P-ReSOCs.
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Appearing as an innovative and efficient strategy, a facile strategy of a plasma ball mill is carried out to prepare few-layer black phosphorus nanosheets (BPNSs), for abating the fire risk of epoxy resin (EP). A spear and shield-inspired Ar plasma emergeed through a plasma ball mill to prevent Ar@BP nanosheets from oxidation compared with the preparation of BP nanosheets (MBPNSs) in a mechanical ball mill. The absorption coefficient in the synchrotron radiation spectrum is increased by 16.91%, indicating that BP is effectively protected by Ar proof. The Vienna ab initio simulation reveals that the combination of Ar@BP with oxygen cannot proceed spontaneously with the binding energy of 4.44 eV. With the introduction of 1.5 wt% Ar@BP, the total heat release (THR), total smoke release (TSR), total smoke production(TSP), CO, and CO2 yield, compared with that of EP, are descended by 30.40%, 24.41%, 24.10%, 33.23%, and 37.60%, respectively, indicating excellent flame retardancy property. It is attributed to the condensed and gas phase function. Meanwhile, the tensile strength and elongation at break increase by 27.92% and 56.04%, respectively, with the incorporation of 1.5 wt% Ar@BP.
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Echovirus 30 (E30), a member of species B enterovirus, is associated with outbreaks of aseptic meningitis and has become a global health emergency. However, the pathogenesis of E30 remains poorly understood due to the lack of appropriate animal models. In this study, we established a mouse infection model to explore the pathogenicity of E30. The 2-day-old IFNAR-/- mice infected with E30 strain WZ16 showed lethargy and paralysis, and some died. Obvious pathological changes were observed in the skeletal muscle, brain tissue, and other tissues, with the highest viral load in the skeletal muscles. Transcriptome analysis of brain and skeletal muscle tissues from infected mice showed that significant differentially expressed genes were enriched in complement response and neuropathy-related pathways. Using immunofluorescence assay, we found that the viral double-stranded RNA (dsRNA) was detected in the mouse brain region and could infect human glioma (U251) cells. These results indicated that E30 affects the nervous system, and they provide a theoretical basis for understanding its pathogenesis. IMPORTANCE Echovirus 30 (E30) infection causes a wide spectrum of diseases with mild symptoms, such as hand, foot, and mouth disease (HFMD), acute flaccid paralysis, and aseptic meningitis and other diseases, especially one of the most common pathogens causing aseptic meningitis outbreaks. We established a novel mouse model of E30 infection by inoculating neonatal mice with clinical isolates of E30 and observed the pathological changes induced by E30. Using the E30 infection model, we found complement responses and neuropathy-related genes in the mice tissues at the transcriptome level. Moreover, we found that the viral dsRNA localized in the mouse brain and could replicate in human glioma cell line U251 rather than in the neuroblastoma cell line, SK-N-SH.
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Modelos Animales de Enfermedad , Infecciones por Echovirus , Glioma , Animales , Línea Celular Tumoral , Infecciones por Echovirus/patología , Enterovirus Humano B/patogenicidad , Humanos , Meningitis Aséptica/patología , Meningitis Aséptica/virología , Ratones , Ratones Noqueados , Filogenia , ARN Viral/genética , Análisis de Secuencia de ADNRESUMEN
Nitrate allocation in Arabidopsis (Arabidopsis thaliana) represents an important mechanism for mediating plant environmental adaptation. However, whether this mechanism occurs or has any physiological/agronomic importance in the ammoniphilic plant rice (Oriza sativa L.) remains unknown. Here, we address this question through functional characterization of the Nitrate transporter 1/Peptide transporter Family (NPF) transporter gene OsNPF7.9. Ectopic expression of OsNPF7.9 in Xenopus oocytes revealed that the gene encodes a low-affinity nitrate transporter. Histochemical and in-situ hybridization assays showed that OsNPF7.9 expresses preferentially in xylem parenchyma cells of vasculature tissues. Transient expression assays indicated that OsNPF7.9 localizes to the plasma membrane. Nitrate allocation from roots to shoots was essentially decreased in osnpf7.9 mutants. Biomass, grain yield, and nitrogen use efficiency (NUE) decreased in the mutant dependent on nitrate availability. Further analysis demonstrated that nitrate allocation mediated by OsNPF7.9 is essential for balancing rice growth and stress tolerance. Moreover, our research identified an indica-japonica divergent single-nucleotide polymorphism occurring in the coding region of OsNPF7.9, which correlates with enhanced nitrate allocation to shoots of indica rice, revealing that divergent nitrate allocation might represent an important component contributing to the divergent NUE between indica and japonica subspecies and was likely selected as a favorable trait during rice breeding.
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Arabidopsis , Oryza , Arabidopsis/genética , Arabidopsis/metabolismo , Transportadores de Nitrato , Nitratos/metabolismo , Nitrógeno/metabolismo , Oryza/metabolismo , Fitomejoramiento , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismoRESUMEN
As a special type of glaucoma, Posner-Schlossman syndrome (PSS) is characterized by elevated intraocular pressure (IOP) and anterior uveitis. Cytomegalovirus (CMV) anterior chamber infection has now been considered the leading cause of PSS. We used murine CMV (MCMV) intracameral injection to establish a rat model manifested in IOP elevation and mild anterior uveitis, much like PSS; viral localization and gene expression at various time points and inflammatory cell infiltration derived from innate and adaptive immunity were investigated, as well as pathogenetic changes of the trabecular meshwork (TM). The IOP and uveitic manifestations peaked at 24 h post-infection (p.i.) and returned to normal after 96 h; the iridocorneal angle remained open consistently. At 24 h p.i., leucocytes gathered at the chamber angle. Maximum transcription of MCMV immediate early 1 (IE1) was reached at 24 h in the cornea and 48 h in the iris and ciliary body. MCMV localized in aqueous humor outflow facilities and the iris from 24 h to 28 d p.i. and was detected by in situ hybridization, though it did not transcribe after 7 d p.i. TM and iris pigment epithelial cells harboring viral inclusion bodies and autophagosomes were present at 28 d p.i. These findings shed light on how and where innate and adaptive immunity reacted after MCMV was found and transcribed in a highly ordered cascade, as well as pathogenetic changes in TM as a result of virus and uveitis behaviors.
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Infecciones por Citomegalovirus , Glaucoma de Ángulo Abierto , Glaucoma , Muromegalovirus , Uveítis Anterior , Uveítis , Ratones , Animales , Ratas , Malla Trabecular , Uveítis/metabolismo , Glaucoma/metabolismo , Glaucoma de Ángulo Abierto/metabolismo , Infecciones por Citomegalovirus/complicaciones , Infecciones por Citomegalovirus/metabolismo , Uveítis Anterior/metabolismo , Humor Acuoso/metabolismo , Presión IntraocularRESUMEN
Minerals played a crucial role in the chemical evolution of small molecules into biopolymers. Yet, it is still not clear how the minerals are related to the formation and the evolution of protocells on early Earth. In this work, using the coacervate formed by quaternized dextran (Q-dextran) and single-stranded oligonucleotides (ss-oligo) as the protocell model, we systematically studied the phase separation of Q-dextran and ss-oligo on the muscovite surface. Serving as rigid and 2D polyelectrolytes, the muscovite surface can be treated by Q-dextran to become negatively charged, neutral, or positively charged. We observed that Q-dextran and ss-oligo form uniform coacervates on naked and neutral muscovite surfaces, while they form biphasic coacervates containing Q-dextran-rich phases and ss-oligo-rich phases on positively or negatively charged muscovite surfaces that were pretreated by Q-dextran. The evolution of the phases is caused by the redistribution of the components as the coacervate touches the surface. Our study indicates that the mineral surface could be a potential driving force for the formation of protocells with hierarchical structures and desirable functions on prebiotic Earth.