Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 199
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Immunity ; 52(5): 767-781.e6, 2020 05 19.
Artículo en Inglés | MEDLINE | ID: mdl-32277911

RESUMEN

The enzyme cyclic GMP-AMP synthase (cGAS) senses cytosolic DNA in infected and malignant cells and catalyzes the formation of 2'3'cGMP-AMP (cGAMP), which in turn triggers interferon (IFN) production via the STING pathway. Here, we examined the contribution of anion channels to cGAMP transfer and anti-viral defense. A candidate screen revealed that inhibition of volume-regulated anion channels (VRACs) increased propagation of the DNA virus HSV-1 but not the RNA virus VSV. Chemical blockade or genetic ablation of LRRC8A/SWELL1, a VRAC subunit, resulted in defective IFN responses to HSV-1. Biochemical and electrophysiological analyses revealed that LRRC8A/LRRC8E-containing VRACs transport cGAMP and cyclic dinucleotides across the plasma membrane. Enhancing VRAC activity by hypotonic cell swelling, cisplatin, GTPγS, or the cytokines TNF or interleukin-1 increased STING-dependent IFN response to extracellular but not intracellular cGAMP. Lrrc8e-/- mice exhibited impaired IFN responses and compromised immunity to HSV-1. Our findings suggest that cell-to-cell transmission of cGAMP via LRRC8/VRAC channels is central to effective anti-viral immunity.


Asunto(s)
Fibroblastos/inmunología , Interferones/inmunología , Proteínas de la Membrana/inmunología , Nucleótidos Cíclicos/inmunología , Canales Aniónicos Dependientes del Voltaje/inmunología , Animales , Antivirales/inmunología , Antivirales/metabolismo , Efecto Espectador , Línea Celular , Células Cultivadas , Embrión de Mamíferos/citología , Embrión de Mamíferos/metabolismo , Fibroblastos/citología , Fibroblastos/metabolismo , Células HeLa , Herpes Simple/inmunología , Herpes Simple/virología , Herpesvirus Humano 1/inmunología , Herpesvirus Humano 1/fisiología , Humanos , Interferones/metabolismo , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Ratones Endogámicos C57BL , Ratones Noqueados , Nucleótidos Cíclicos/metabolismo , Nucleotidiltransferasas/genética , Nucleotidiltransferasas/inmunología , Nucleotidiltransferasas/metabolismo , Canales Aniónicos Dependientes del Voltaje/metabolismo
2.
J Immunol ; 213(4): 494-505, 2024 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-38967520

RESUMEN

Stimulator of IFN genes (STING) is a critical component of the innate immune system, playing an essential role in defending against DNA virus infections. However, the mechanisms governing basal STING regulation remain poorly understood. In this study, we demonstrate that the basal level of STING is critically maintained by hypoxia-inducible factor 1 (HIF-1)α through transcription. Under normal conditions, HIF-1α binds constitutively to the promoter region of STING, actively promoting its transcription. Knocking down HIF-1α results in a decrease in STING expression in multiple cell lines and zebrafish, which in turn reduces cellular responses to synthetic dsDNAs, including cell signaling and IFN production. Moreover, this decrease in STING levels leads to an increase in cellular susceptibility to DNA viruses HSV-1 and pseudorabies virus. These findings unveil a (to our knowledge) novel role of HIF-1α in maintaining basal STING levels and provide valuable insights into STING-mediated antiviral activities and associated diseases.


Asunto(s)
Herpesvirus Humano 1 , Subunidad alfa del Factor 1 Inducible por Hipoxia , Inmunidad Innata , Proteínas de la Membrana , Pez Cebra , Animales , Proteínas de la Membrana/genética , Proteínas de la Membrana/inmunología , Humanos , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Subunidad alfa del Factor 1 Inducible por Hipoxia/inmunología , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Pez Cebra/inmunología , Herpesvirus Humano 1/inmunología , Herpesvirus Suido 1/inmunología , Inmunidad Celular , Regulación de la Expresión Génica/inmunología , Transducción de Señal/inmunología , Transcripción Genética/inmunología , Regiones Promotoras Genéticas , Células HEK293 , Línea Celular , Herpes Simple/inmunología , Seudorrabia/inmunología
3.
Brief Bioinform ; 24(2)2023 03 19.
Artículo en Inglés | MEDLINE | ID: mdl-36857616

RESUMEN

With the emergence of multidrug-resistant bacteria, antimicrobial peptides (AMPs) offer promising options for replacing traditional antibiotics to treat bacterial infections, but discovering and designing AMPs using traditional methods is a time-consuming and costly process. Deep learning has been applied to the de novo design of AMPs and address AMP classification with high efficiency. In this study, several natural language processing models were combined to design and identify AMPs, i.e. sequence generative adversarial nets, bidirectional encoder representations from transformers and multilayer perceptron. Then, six candidate AMPs were screened by AlphaFold2 structure prediction and molecular dynamic simulations. These peptides show low homology with known AMPs and belong to a novel class of AMPs. After initial bioactivity testing, one of the peptides, A-222, showed inhibition against gram-positive and gram-negative bacteria. The structural analysis of this novel peptide A-222 obtained by nuclear magnetic resonance confirmed the presence of an alpha-helix, which was consistent with the results predicted by AlphaFold2. We then performed a structure-activity relationship study to design a new series of peptide analogs and found that the activities of these analogs could be increased by 4-8-fold against Stenotrophomonas maltophilia WH 006 and Pseudomonas aeruginosa PAO1. Overall, deep learning shows great potential in accelerating the discovery of novel AMPs and holds promise as an important tool for developing novel AMPs.


Asunto(s)
Antibacterianos , Aprendizaje Profundo , Antibacterianos/farmacología , Péptidos Catiónicos Antimicrobianos/farmacología , Bacterias Gramnegativas , Péptidos Antimicrobianos , Bacterias Grampositivas , Simulación de Dinámica Molecular
4.
J Am Chem Soc ; 146(32): 22220-22235, 2024 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-39088252

RESUMEN

High-voltage layered oxide cathodes attract great attention for sodium-ion batteries (SIBs) due to the potential high energy density, but high voltage usually leads to rapid capacity decay. Herein, a stable high-voltage NaLi0.1Ni0.35Mn0.3Ti0.25O2 cathode with a ribbon-ordered superlattice is reported, and the intrinsic coupling mechanism between structure evolution and the anion redox reaction (ARR) is revealed. Li introduction constructs a special Li-O-Na configuration activating reversible nonbonded O 2p (|O2p)-type ARR and regulates the structure evolution way, enabling the reversible Li ions out-of-layer migration instead of the irreversible transition metal ions out-of-layer migration. The reversible structure evolution enhances the reversibility of the bonded O 2p (O2p)-type ARR and inhibits the generation of oxygen dimers, thus suppressing the irreversible molecular oxygen (O2)-type ARR. After the structure regulation, the structure evolution becomes reversible, |O2p-type ARR is activated, O2p-type ARR becomes stable, and O2-type ARR is inhibited, which largely suppresses the capacity degradation and voltage decay. The discharge capacity is increased from 154 to 168 mA h g-1, the capacity retention after 200 cycles significantly increases from 35 to 84%, and the voltage retention increases from 78 to 93%. This study presents some guidance for the design of high-voltage, O3-type oxide cathodes for high-performance SIBs.

5.
Small ; : e2401839, 2024 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-38804822

RESUMEN

Co-free Li-rich Mn-based cathode materials are garnering great interest because of high capacity and low cost. However, their practical application is seriously hampered by the irreversible oxygen escape and the poor cycling stability. Herein, a reversible lattice adjustment strategy is proposed by integrating O vacancies and B doping. B incorporation increases TM─O (TM: transition metal) bonding orbitals whereas decreases the antibonding orbitals. Moreover, B doping and O vacancies synergistically increase the crystal orbital bond index values enhancing the overall covalent bonding strength, which makes TM─O octahedron more resistant to damage and enables the lattice to better accommodate the deformation and reaction without irreversible fracture. Furthermore, Mott-Hubbard splitting energy is decreased due to O vacancies, facilitating electron leaps, and enhancing the lattice reactivity and capacity. Such a reversible lattice, more amenable to deformation and forestalling fracturing, markedly improves the reversibility of lattice reactions and mitigates TM migration and the irreversible oxygen redox which enables the high cycling stability and high rate capability. The modified cathode demonstrates a specific capacity of 200 mAh g-1 at 1C, amazingly sustaining the capacity for 200 cycles without capacity degradation. This finding presents a promising avenue for solving the long-term cycling issue of Li-rich cathode.

6.
Appl Environ Microbiol ; 90(5): e0004624, 2024 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-38563787

RESUMEN

Dietary fiber metabolism by gut microorganisms plays important roles in host physiology and health. Alginate, the major dietary fiber of daily diet seaweeds, is drawing more attention because of multiple biological activities. To advance the understanding of alginate assimilation mechanism in the gut, we show the presence of unsaturated alginate oligosaccharides (uAOS)-specific alginate utilization loci (AUL) in human gut microbiome. As a representative example, a working model of the AUL from the gut microorganism Bacteroides clarus was reconstructed from biochemistry and transcriptome data. The fermentation of resulting monosaccharides through Entner-Doudoroff pathway tunes the metabolism of short-chain fatty acids and amino acids. Furthermore, we show that uAOS feeding protects the mice against dextran sulfate sodium-induced acute colitis probably by remodeling gut microbiota and metabolome. IMPORTANCE: Alginate has been included in traditional Chinese medicine and daily diet for centuries. Recently discovered biological activities suggested that alginate-derived alginate oligosaccharides (AOS) might be an active ingredient in traditional Chinese medicine, but how these AOS are metabolized in the gut and how it affects health need more information. The study on the working mechanism of alginate utilization loci (AUL) by the gut microorganism uncovers the role of unsaturated alginate oligosaccharides (uAOS) assimilation in tuning short-chain fatty acids and amino acids metabolism and demonstrates that uAOS metabolism by gut microorganisms results in a variation of cell metabolites, which potentially contributes to the physiology and health of gut.


Asunto(s)
Alginatos , Microbioma Gastrointestinal , Oligosacáridos , Alginatos/metabolismo , Oligosacáridos/metabolismo , Ratones , Animales , Humanos , Colitis/microbiología , Colitis/inducido químicamente , Ratones Endogámicos C57BL , Ácidos Grasos Volátiles/metabolismo , Inflamación/metabolismo , Sulfato de Dextran , Fibras de la Dieta/metabolismo
7.
J Cardiovasc Pharmacol ; 84(1): 45-57, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38922585

RESUMEN

ABSTRACT: Atherosclerosis (AS) is a chronic progressive disease caused by various factors and causes various cerebrovascular and cardiovascular diseases (CVDs). Reducing the plasma levels of low-density lipoprotein cholesterol is the primary goal in preventing and treating AS. Proprotein convertase subtilisin/kexin type 9 (PCSK9) plays a crucial role in regulating low-density lipoprotein cholesterol metabolism. Panax notoginseng has potent lipid-reducing effects and protects against CVDs, and its saponins induce vascular dilatation, inhibit thrombus formation, and are used in treating CVDs. However, the anti-AS effect of the secondary metabolite, 20( S )-protopanaxatriol (20( S )-PPT), remains unclear. In this study, the anti-AS effect and molecular mechanism of 20( S )-PPT were investigated in vivo and in vitro by Western blotting, real-time polymerase chain reaction, enzyme-linked immunosorbent assay, immunofluorescence staining, and other assays. The in vitro experiments revealed that 20( S )-PPT reduced the levels of PCSK9 in the supernatant of HepG2 cells, upregulated low-density lipoprotein receptor protein levels, promoted low-density lipoprotein uptake by HepG2 cells, and reduced PCSK9 mRNA transcription by upregulating the levels of forkhead box O3 protein and mRNA and decreasing the levels of HNF1α and SREBP2 protein and mRNA. The in vivo experiments revealed that 20( S )-PPT upregulated aortic α-smooth muscle actin expression, increased the stability of atherosclerotic plaques, and reduced aortic plaque formation induced by a high-cholesterol diet in ApoE -/- mice (high-cholesterol diet-fed group). Additionally, 20( S )-PPT reduced the aortic expression of CD68, reduced inflammation in the aortic root, and alleviated the hepatic lesions in the high-cholesterol diet-fed group. The study revealed that 20( S )-PPT inhibited low-density lipoprotein receptor degradation via PCSK9 to alleviate AS.


Asunto(s)
Aorta , Enfermedades de la Aorta , Aterosclerosis , Modelos Animales de Enfermedad , Ratones Endogámicos C57BL , Ratones Noqueados para ApoE , Placa Aterosclerótica , Proproteína Convertasa 9 , Receptores de LDL , Sapogeninas , Animales , Aterosclerosis/metabolismo , Aterosclerosis/patología , Aterosclerosis/tratamiento farmacológico , Aterosclerosis/prevención & control , Aterosclerosis/genética , Sapogeninas/farmacología , Proproteína Convertasa 9/metabolismo , Proproteína Convertasa 9/genética , Receptores de LDL/genética , Receptores de LDL/metabolismo , Humanos , Masculino , Enfermedades de la Aorta/patología , Enfermedades de la Aorta/prevención & control , Enfermedades de la Aorta/metabolismo , Enfermedades de la Aorta/genética , Enfermedades de la Aorta/tratamiento farmacológico , Aorta/efectos de los fármacos , Aorta/metabolismo , Aorta/patología , Proteolisis/efectos de los fármacos , Células Hep G2 , Inhibidores de PCSK9 , Transducción de Señal/efectos de los fármacos , Proteína 2 de Unión a Elementos Reguladores de Esteroles/metabolismo , Proteína 2 de Unión a Elementos Reguladores de Esteroles/genética , Ratones , Dieta Alta en Grasa , Apolipoproteínas E
8.
Org Biomol Chem ; 22(6): 1157-1161, 2024 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-38224149

RESUMEN

Herein, a photoinduced direct C(sp2)-H alkylation of N-heteroaromatics by using commercially available tetrabutylammonium tribromide (TBATB) as a HAT reagent is described. The method uses O2 as the oxidant, and features metal-free, mild reaction conditions and good functional group compatibility.

9.
BMC Cardiovasc Disord ; 24(1): 43, 2024 Jan 13.
Artículo en Inglés | MEDLINE | ID: mdl-38218809

RESUMEN

BACKGROUND: Cardiac masses can encompass a variety of conditions, such as tumors, thrombi, vegetations, calcific lesions, and other rare diseases. Treatment and management of these types of cardiac masses differ considerably. Thus, accurately distinguishing among thrombi, benign tumors, and malignant tumors in the heart is of great importance. Contrast echocardiography (CE) has emerged as a promising technology. Although published guidelines suggest that CE can enhance image quality and assist in differentiating between benign and malignant lesions, most studies on CE diagnosis of cardiac masses are limited to case reports or retrospective/small-sample-sized prospective cohorts. This study aims to evaluate the diagnostic accuracy of CE in patients with suspected cardiac masses and address the insufficient evidence for differential diagnosis using CE. METHODS: Between April 2018 and July 2022, a prospective multicenter study was conducted, which included 145 consecutive patients suspected to have cardiac masses based on transthoracic echocardiography. All patients underwent CE examinations. The echocardiographic diagnosis relied on qualitative factors such as echogenicity, boundary, morphology of the base, mass perfusion, pericardial effusion, and motility as well as quantitative factors such as the area of the masses and the peak intensity ratio of the masses to adjacent myocardium (A1/A2). RESULTS: The final confirmed diagnoses were as follows: 2 patients had no cardiac mass, 4 patients had pseudomass, 43 patients had thrombus, 66 patients had benign tumors, and 30 patients had malignant tumors. The receiver operating characteristic (ROC) analysis indicated that an optimal A1/A2 cutoff value of 0.499 distinguished a cardiac tumor from a thrombus, with AUC, sensitivity, specificity, PPV, and NPV of 0.977, 97.9%, 90.7%, 95.9%, and 95.1%, respectively. The optimal A1/A2 cutoff value of 1.583 distinguished a cardiac tumor from a thrombus, with AUC, sensitivity, specificity, PPV, and NPV of 0.950, 93.3%, 93.9%, 87.5%, and 96.9%, respectively. CONCLUSIONS: Combined with qualitative and quantitative analyses, CE has the potential to accurately differentiate among different types of cardiac masses.


Asunto(s)
Neoplasias Cardíacas , Trombosis , Humanos , Estudios Retrospectivos , Estudios Prospectivos , Medios de Contraste , Ecocardiografía/métodos , Neoplasias Cardíacas/diagnóstico por imagen , Diagnóstico Diferencial , Sensibilidad y Especificidad
10.
Clin Oral Investig ; 28(3): 188, 2024 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-38430316

RESUMEN

OBJECTIVES: Root-end filling is important for the clinical outcome of endodontic microsurgery. Our previous study showed that combined application of iRoot BP Plus Root Repair Material (BP-RRM) and iRoot SP Injectable Root Canal Sealer (SP-RCS) in root-end filling exhibited better apical sealing as compared to the application of BP-RRM alone. The aim of this randomized controlled clinical trial was to evaluate the effect of the combined use of BP-RRM and SP-RCS on the prognosis of teeth with refractory periapical diseases after endodontic microsurgery. MATERIALS AND METHODS: 240 teeth with refractory periapical diseases scheduled for endodontic microsurgery were randomly divided into BP-RRM/SP-RCS group (n = 120) and BP-RRM group (n = 120). The patients were followed up at 3 months, 6 months, and 12 months after endodontic microsurgery. Pre- and post-operative clinical and radiographic examinations were performed to evaluate the treatment outcome. The 1-year success rate of endodontic microsurgery in BP-RRM/SP-RCS and BP-RRM groups was compared by Chi-square test. Factors that might impact the prognosis were further analyzed using Chi-square test or Fisher's exact test. RESULTS: A total of 221 teeth completed the 12-month follow-up. The 1-year success rates of the BP-RRM/SP-RCS and BP-RRM groups were 94.5% (104/110) and 92.8% (103/111), respectively. The combined use of BP-RRM and SP-RCS achieved a clinical outcome comparable to BP-RRM alone (P = 0.784). Tooth type (P = 0.002), through-and-through/apico-marginal lesion (P = 0.049), periodontal status (P < 0.0001), and Kim's lesion classification (P < 0.0001) were critical factors associated with the 1-year success of endodontic microsurgery. CONCLUSIONS: The combined use of BP-RRM and SP-RCS is a practicable method for root-end filling in endodontic microsurgery with a satisfactory 1-year clinical outcome. CLINICAL RELEVANCE: The combined application of BP-RRM and SP-RCS in EMS is an effective root-end filling method with a satisfactory 1-year clinical outcome. TRIAL REGISTRATION: This study was registered in the Chinese Clinical Trial Registry (ChiCTR2100052174).


Asunto(s)
Enfermedades Periapicales , Materiales de Obturación del Conducto Radicular , Humanos , Compuestos de Calcio/uso terapéutico , Microcirugia/métodos , Materiales de Obturación del Conducto Radicular/uso terapéutico , Silicatos/uso terapéutico
11.
J Am Chem Soc ; 2023 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-36763965

RESUMEN

In contrast to the traditional and widely-used cycloaddition reactions involving at least a π bond component, a [2σ + 2σ] radical cycloaddition between bicyclo[1.1.0]butanes (BCBs) and cyclopropyl ketones has been developed to provide a modular, concise, and atom-economical synthetic route to substituted bicyclo[3.1.1]heptane (BCH) derivatives that are 3D bioisosteres of benzenes and core skeleton of a number of terpene natural products. The reaction was catalyzed by a combination of simple tetraalkoxydiboron(4) compound B2pin2 and 3-pentyl isonicotinate. The broad substrate scope has been demonstrated by synthesizing a series of new highly functionalized BCHs with up to six substituents on the core with up to 99% isolated yield. Computational mechanistic investigations supported a pyridine-assisted boronyl radical catalytic cycle.

12.
J Am Chem Soc ; 145(51): 28184-28190, 2023 Dec 27.
Artículo en Inglés | MEDLINE | ID: mdl-38096486

RESUMEN

The manipulation of two-dimensional (2D) magnetic order is of significant importance to facilitate future 2D magnets for low-power and high-speed spintronic devices. van der Waals stacking engineering makes promises for controllable magnetism via interlayer magnetic coupling. However, directly examining the stacking order changes accompanying magnetic order transitions at the atomic scale and preparing device-ready 2D magnets with controllable magnetic orders remain elusive. Here, we demonstrate the effective control of interlayer stacking in exfoliated CrBr3 via thermally assisted strain engineering. The stable interlayer ferromagnetic (FM), antiferromagnetic (AFM), and FM-AFM coexistent ground states confirmed by the magnetic circular dichroism measurements are realized. Combined with the first-principles calculations, the atomically resolved imaging technique reveals the correlation between magnetic order and interlayer stacking order in CrBr3 flakes unambiguously. A tunable exchange bias effect is obtained in the mixed phase of FM and AFM states. This work will introduce new magnetic properties by controlling the stacking order and sequence of 2D magnets, providing ample opportunities for their application in spintronic devices.

13.
Small ; 19(33): e2300964, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37066740

RESUMEN

The long-range magnetic ordering in frustrated magnetic systems is stabilized by coupling magnetic moments to various degrees of freedom, for example, by enhancing magnetic anisotropy via lattice distortion. Here, the unconventional spin-lattice coupled metamagnetic properties of atomically-thin CrOCl, a van der Waals antiferromagnet with inherent magnetic frustration rooted in the staggered square lattice, are reported. Using temperature- and angle-dependent tunneling magnetoconductance (TMC), in complementary with magnetic torque and first-principles calculations, the antiferromagnetic (AFM)-to-ferrimagnetic (FiM) metamagnetic transitions (MTs) of few-layer CrOCl are revealed to be triggered by collective magnetic moment flipping rather than the established spin-flop mechanism, when external magnetic field (H) enforces a lattice reconstruction interlocked with the five-fold periodicity of the FiM phase. The spin-lattice coupled MTs are manifested by drastic jumps in TMC, which show anomalous upshifts at the transition thresholds and persist much higher above the AFM Néel temperature. While the MTs exhibit distinctive triaxial anisotropy, reflecting divergent magnetocrystalline anisotropy of the c-axis AFM ground state, the resulting FiM phase has an a-c easy plane in which the magnetization axis is freely rotated by H. At the 2D limit, such a field-tunable FiM phase may provide unique opportunities to explore exotic emergent phenomena and novel spintronics devices.

14.
J Virol ; 96(13): e0217121, 2022 07 13.
Artículo en Inglés | MEDLINE | ID: mdl-35708311

RESUMEN

The alphaherpesvirus pseudorabies virus (PRV) is the etiologic agent of swine Aujeszky's disease, which can cause huge economic losses to the pig industry. PRV can overcome a type I interferon (IFN)-induced antiviral state in host cells through its encoded EP0 protein. However, the exact role of EP0 in this process is poorly defined. Here, we report that EP0 transcriptionally represses IFN regulatory factor 9 (IRF9), a critical component in the IFN signaling pathway, thereby reducing the cellular levels of IRF9 and inhibiting IFN-induced gene transcription. This activity of EP0 is mediated by its C-terminal region independently of the RING domain. Moreover, compared with EP0 wild-type PRV, EP0-deficient PRV loses the ability to efficiently decrease cellular IRF9, while reintroducing the C-terminal region of EP0 back into the EP0-deficient virus restores the activity. Together, these results suggest that EP0 can transcriptionally modulate IRF9-mediated antiviral pathways through its C-terminal region, contributing to PRV innate immune evasion. IMPORTANCE Alphaherpesviruses can establish lifelong infections and cause many diseases in humans and animals. Pseudorabies virus (PRV) is a swine alphaherpesvirus that threatens pig production. Using PRV as a model, we found that alphaherpesvirus can utilize its encoded early protein EP0 to inhibit the IFN-induced upregulation of antiviral proteins by reducing the basal expression levels of IRF9 through repressing its transcription. Our findings reveal a mechanism employed by alphaherpesvirus to evade the immune response and indicate that EP0 is an important viral protein in pathogenesis and a potential target for antiviral drug development.


Asunto(s)
Herpesvirus Suido 1 , Interferón Tipo I , Subunidad gamma del Factor 3 de Genes Estimulados por el Interferón , Seudorrabia , Enfermedades de los Porcinos , Animales , Antivirales/farmacología , Regulación de la Expresión Génica/inmunología , Herpesvirus Suido 1/inmunología , Herpesvirus Suido 1/metabolismo , Interacciones Microbiota-Huesped/inmunología , Interferón Tipo I/metabolismo , Subunidad gamma del Factor 3 de Genes Estimulados por el Interferón/metabolismo , Seudorrabia/inmunología , Seudorrabia/virología , Porcinos , Enfermedades de los Porcinos/inmunología , Enfermedades de los Porcinos/virología , Proteínas Virales/genética , Proteínas Virales/inmunología , Proteínas Virales/metabolismo
15.
Inorg Chem ; 62(24): 9314-9323, 2023 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-37285310

RESUMEN

P2-type Na0.67Mn0.5Fe0.5O2 (MF) has attracted great interest as a promising cathode material for sodium-ion batteries (SIBs) due to its high specific capacity and low cost. However, its poor cyclic stability and rate performance hinder its practical applications, which is largely related to lattice oxygen instability. Here, we propose to coat the cathode of SIBs with Li2ZrO3, which realizes the "three-in-one" modification of Li2ZrO3 coating and Li+, Zr4+ co-doping. The synergy of Li2ZrO3 coating and Li+/Zr4+ doping improves both the cycle stability and rate performance, and the underlying modification mechanism is revealed by a series of characterization methods. The doping of Zr4+ increases the interlayer spacing of MF, reduces the diffusion barrier of Na+, and reduces the ratio of Mn3+/Mn4+, thus inhibiting the Jahn-Teller effect. The Li2ZrO3 coating layer inhibits the side reaction between the cathode and the electrolyte. The synergy of Li2ZrO3 coating and Li+, Zr4+ co-doping enhances the stability of lattice oxygen and the reversibility of anionic redox, which improves the cycle stability and rate performance. This study provides some insights into stabilizing the lattice oxygen in layered oxide cathodes for high-performance SIBs.

16.
J Immunol ; 206(9): 2061-2074, 2021 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-33827893

RESUMEN

The recently identified anion channel LRRC8 volume-regulated anion channels (VRACs) are heteromeric hexamers constituted with the obligate LRRC8A subunit paired with at least one of the accessory LRRC8B to LRRC8E subunits. In addition to transport chloride, taurine, and glutamate, LRRC8 VRACs also transport the anticancer agent cisplatin and STING agonists 2'3'-cyclic GMP-AMP (cGAMP) and cyclic dinucleotides; hence, they are implicated in a variety of physiological and pathological processes, such as cell swelling, stroke, cancer, and viral infection. Although the subunit composition largely determines VRAC substrate specificity, the opening of various VRAC pores under physiological and pathological settings remains enigmatic. In this study, we demonstrated that VRACs comprising LRRC8A and LRRC8E (LRRC8A/E-containing VRACs), specialized in cGAMP transport, can be opened by a protein component present in serum under resting condition. Serum depletion ablated the tonic activity of LRRC8A/E-containing VRACs, decreasing cGAMP transport in various human and murine cells. Also, heating or proteinase K treatment abolished the ability of serum to activate VRAC. Genetic analyses revealed a crucial role for cGAMP synthase (cGAS) in serum/TNF-promoted VRAC activation. Notably, the presence of cGAS on the plasma membrane, rather than its DNA-binding or enzymatic activity, enabled VRAC activation. Moreover, phospholipid PIP2 seemed to be instrumental in the membrane localization of cGAS and its association with VRACs. Corroborating a role for LRRC8A/D-containing VRACs in cisplatin transport, serum and TNF markedly potentiated cisplatin uptake and killing of cancer cells derived from human or mouse. Together, these observations provide new insights into the complex regulation of VRAC activation and suggest a novel approach to enhance the efficacy of cGAMP and cisplatin in treating infection and cancer.


Asunto(s)
Antineoplásicos/farmacología , Cisplatino/farmacología , Inflamación/tratamiento farmacológico , Proteínas de la Membrana/inmunología , Nucleótidos Cíclicos/farmacología , Animales , Antineoplásicos/inmunología , Cisplatino/inmunología , Inflamación/inmunología , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Nucleótidos Cíclicos/inmunología
17.
Cell Mol Life Sci ; 79(8): 403, 2022 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-35799071

RESUMEN

Endoplasmic reticulum (ER) stress initiates the unfolded protein response (UPR) and is decisive for tumor cell growth and tumor microenvironment (TME) maintenance. Tumor cells persistently undergo ER stress and could transmit it to the neighboring macrophages and surroundings. Tumor infiltrating macrophages can also adapt to the microenvironment variations to fulfill their highly energy-demanding and biological functions via ER stress. However, whether the different macrophage populations differentially sense ER stress and transmit ER stress to surrounding tumor cells has not yet been elucidated. Here, we aimed to investigate the role of transmissible ER stress, a novel regulator of intercellular communication in the TME. Murine bone marrow-derived macrophage (BMDM) can be polarized toward distinct functional endpoints termed classical (M1) and alternative (M2) activation, and their polarization status has been shown to be tightly correlated with their functional significance. We showed that tumor cells could receive the transmissible ER stress from two differentially polarized macrophage populations with different extent of ER stress activation. The proinflammatory M1-like macrophages respond to ER stress with less extent, however they could transmit more ER stress to tumor cells. Moreover, by analyzing the secreted components of two ER-stressed macrophage populations, we identified certain damage-associated molecular patterns (DAMPs), including S100A8 and S100A9, which are dominantly secreted by M1-like macrophages could lead to significant recipient tumor cells death in synergy with transferred ER stress.


Asunto(s)
Neoplasias , Microambiente Tumoral , Animales , Estrés del Retículo Endoplásmico , Macrófagos/metabolismo , Ratones , Neoplasias/patología , Respuesta de Proteína Desplegada
18.
Proc Natl Acad Sci U S A ; 117(26): 15047-15054, 2020 06 30.
Artículo en Inglés | MEDLINE | ID: mdl-32532922

RESUMEN

Tamoxifen, a widely used modulator of the estrogen receptor (ER), targets ER-positive breast cancer preferentially. We used a powerful validation-based insertion mutagenesis method to find that expression of a dominant-negative, truncated form of the histone deacetylase ZIP led to resistance to tamoxifen. Consistently, increased expression of full-length ZIP gives the opposite phenotype, inhibiting the expression of genes whose products mediate resistance. An important example is JAK2 By binding to two specific sequences in the promoter, ZIP suppresses JAK2 expression. Increased expression and activation of JAK2 when ZIP is inhibited lead to increased STAT3 phosphorylation and increased resistance to tamoxifen, both in cell culture experiments and in a mouse xenograft model. Furthermore, data from human tumors are consistent with the conclusion that decreased expression of ZIP leads to resistance to tamoxifen in ER-positive breast cancer.


Asunto(s)
Neoplasias de la Mama/enzimología , Proteínas Quinasas Asociadas a Muerte Celular/metabolismo , Resistencia a Antineoplásicos , Janus Quinasa 2/metabolismo , Factor de Transcripción STAT3/metabolismo , Tamoxifeno/farmacología , Animales , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Línea Celular Tumoral , Proteínas Quinasas Asociadas a Muerte Celular/genética , Femenino , Humanos , Janus Quinasa 2/genética , Ratones , Ratones SCID , Receptores de Estrógenos/genética , Receptores de Estrógenos/metabolismo , Factor de Transcripción STAT3/genética
19.
Nano Lett ; 22(21): 8559-8566, 2022 Nov 09.
Artículo en Inglés | MEDLINE | ID: mdl-36259745

RESUMEN

Skyrmions and bimerons are versatile topological spin textures that can be used as information bits for both classical and quantum computing. The transformation between isolated skyrmions and bimerons is an essential operation for computing architecture based on multiple different topological bits. Here we report the creation of isolated skyrmions and their subsequent transformation to bimerons by harnessing the electric current-induced Oersted field and temperature-induced perpendicular magnetic anisotropy variation. The transformation between skyrmions and bimerons is reversible, which is controlled by the current amplitude and scanning direction. Both skyrmions and bimerons can be created in the same system through the skyrmion-bimeron transformation and magnetization switching. Deformed skyrmion bubbles and chiral labyrinth domains are found as nontrivial intermediate transition states. Our results may provide a unique way for building advanced information-processing devices using different types of topological spin textures in the same system.

20.
Nano Lett ; 22(3): 1233-1241, 2022 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-35041438

RESUMEN

Materials with a quasi-one-dimensional stripy magnetic order often exhibit low crystal and magnetic symmetries, thus allowing the presence of various energy coupling terms and giving rise to macroscopic interplay between spin, charge, and phonon. In this work, we performed optical, electrical and magnetic characterizations combined with first-principles calculations on a van der Waals antiferromagnetic insulator chromium oxychloride (CrOCl). We detected the subtle phase transition behaviors of exfoliated CrOCl under varying temperature and magnetic field and clarified its controversial spin structures. We found that the antiferromagnetism and its air stability persist down to few-layer samples, making it a promising candidate for future 2D spintronic devices. Additionally, we verified the magnetoelastic coupling effect in CrOCl, allowing for the potential manipulation of the magnetic states via electric field or strain. These virtues of CrOCl provide us with an ideal platform for fundamental research on spin-charge, spin-phonon coupling, and spin-interactions.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA