Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 4.459
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
Nature ; 2024 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-39326517

RESUMO

One issue that always strands the scaling-up development of perovskite photovoltaics is the significant efficiency drop when enlarging the device area, which is caused by the inhomogeneous distribution of defected sites1-3. In the narrow band gap formamidinium lead iodide (FAPbI3), the native impurities of PbI2 and δ-FAPbI3 non-perovskite could induce unfavored non-radiative recombination, as well as inferior charge transport and extraction 4,5.Here, we develop an impurity-healing interface engineering strategy to well address the issue both in small-area solar cell and large-scale submodule. With the introduction of a functional cation, 2-(1-cyclohexenyl)ethyl ammonium, two-dimensional (2D) perovskite with high mobility is rationally constructed on FAPbI3 to horizontally cover the film surface and vertically penetrate to the grain boundaries of 3D perovskites. Such unique configuration not only comprehensively transforms the PbI2 and δ-FAPbI3 impurities into stable 2D perovskite and realize a uniform defect passivation, but also provides interconnecting channels for efficient carrier transport. As a result, the FAPbI3-based small-area (0.085 cm2) solar cells achieve a champion efficiency over 25.86% with a notably high fill factor (FF) of 86.16%. More encouragingly, the fabricated submodules with the aperture area of 715.1 cm2 obtain a certified record efficiency of 22.46% with a good FF of 81.21%, showcasing the feasibility and effectualness of the impurity-healing interface engineering for scaling-up promotion with well-preserved photovoltaic performance.

2.
Nature ; 625(7993): 148-156, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37993710

RESUMO

The continuing emergence of SARS-CoV-2 variants highlights the need to update COVID-19 vaccine compositions. However, immune imprinting induced by vaccination based on the ancestral (hereafter referred to as WT) strain would compromise the antibody response to Omicron-based boosters1-5. Vaccination strategies to counter immune imprinting are critically needed. Here we investigated the degree and dynamics of immune imprinting in mouse models and human cohorts, especially focusing on the role of repeated Omicron stimulation. In mice, the efficacy of single Omicron boosting is heavily limited when using variants that are antigenically distinct from WT-such as the XBB variant-and this concerning situation could be mitigated by a second Omicron booster. Similarly, in humans, repeated Omicron infections could alleviate WT vaccination-induced immune imprinting and generate broad neutralization responses in both plasma and nasal mucosa. Notably, deep mutational scanning-based epitope characterization of 781 receptor-binding domain (RBD)-targeting monoclonal antibodies isolated from repeated Omicron infection revealed that double Omicron exposure could induce a large proportion of matured Omicron-specific antibodies that have distinct RBD epitopes to WT-induced antibodies. Consequently, immune imprinting was largely mitigated, and the bias towards non-neutralizing epitopes observed in single Omicron exposures was restored. On the basis of the deep mutational scanning profiles, we identified evolution hotspots of XBB.1.5 RBD and demonstrated that these mutations could further boost the immune-evasion capability of XBB.1.5 while maintaining high ACE2-binding affinity. Our findings suggest that the WT component should be abandoned when updating COVID-19 vaccines, and individuals without prior Omicron exposure should receive two updated vaccine boosters.


Assuntos
Anticorpos Antivirais , Vacinas contra COVID-19 , COVID-19 , Imunização Secundária , Memória Imunológica , SARS-CoV-2 , Animais , Humanos , Camundongos , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , COVID-19/imunologia , COVID-19/prevenção & controle , COVID-19/virologia , Vacinas contra COVID-19/administração & dosagem , Vacinas contra COVID-19/imunologia , Epitopos de Linfócito B/imunologia , Memória Imunológica/imunologia , SARS-CoV-2/classificação , SARS-CoV-2/genética , SARS-CoV-2/imunologia , Mutação
3.
Nature ; 614(7948): 521-529, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36535326

RESUMO

Continuous evolution of Omicron has led to a rapid and simultaneous emergence of numerous variants that display growth advantages over BA.5 (ref. 1). Despite their divergent evolutionary courses, mutations on their receptor-binding domain (RBD) converge on several hotspots. The driving force and destination of such sudden convergent evolution and its effect on humoral immunity remain unclear. Here we demonstrate that these convergent mutations can cause evasion of neutralizing antibody drugs and convalescent plasma, including those from BA.5 breakthrough infection, while maintaining sufficient ACE2-binding capability. BQ.1.1.10 (BQ.1.1 + Y144del), BA.4.6.3, XBB and CH.1.1 are the most antibody-evasive strains tested. To delineate the origin of the convergent evolution, we determined the escape mutation profiles and neutralization activity of monoclonal antibodies isolated from individuals who had BA.2 and BA.5 breakthrough infections2,3. Owing to humoral immune imprinting, BA.2 and especially BA.5 breakthrough infection reduced the diversity of the neutralizing antibody binding sites and increased proportions of non-neutralizing antibody clones, which, in turn, focused humoral immune pressure and promoted convergent evolution in the RBD. Moreover, we show that the convergent RBD mutations could be accurately inferred by deep mutational scanning profiles4,5, and the evolution trends of BA.2.75 and BA.5 subvariants could be well foreseen through constructed convergent pseudovirus mutants. These results suggest that current herd immunity and BA.5 vaccine boosters may not efficiently prevent the infection of Omicron convergent variants.


Assuntos
Anticorpos Antivirais , Deriva e Deslocamento Antigênicos , COVID-19 , Evolução Molecular , Imunidade Humoral , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , Humanos , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Infecções Irruptivas/imunologia , Infecções Irruptivas/virologia , COVID-19/imunologia , COVID-19/virologia , Soroterapia para COVID-19 , SARS-CoV-2/química , SARS-CoV-2/genética , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Domínios Proteicos/genética , Domínios Proteicos/imunologia , Deriva e Deslocamento Antigênicos/imunologia , Mutação
4.
EMBO J ; 2024 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-39333773

RESUMO

Inherited deficiency of zinc finger NFX1-type containing 1 (ZNFX1), a dsRNA virus sensor, is associated with severe familial immunodeficiency, multisystem inflammatory disease, increased susceptibility to viruses, and early mortality. However, limited treatments for patients with pathological variants of ZNFX1 exist due to an incomplete understanding of the diseases resulting from ZNFX1 mutations. Here, we demonstrate that ZNFX1 specifically inhibits the activation of the NLR family pyrin domain-containing protein 3 (NLRP3) inflammasome in response to NLRP3 activators both in vitro and in vivo. ZNFX1 retains NLRP3 in the cytoplasm and prevents its accumulation in the TGN38 + /TGN46+ vesicles in the resting state. Upon NLRP3 inflammasome activation, ZNFX1 is cleaved by caspase-1, establishing a feed-forward loop that promotes NLRP3 accumulation in the trans-Golgi network (TGN) and amplifies the activity of the downstream cascade. Expression of wild-type ZNFX1, but not of ZNFX1 with human pathogenic mutations, rescues the impairment of NLRP3 inflammasome inhibition. Our findings reveal a dual role of ZNFX1 in virus sensing and suppression of inflammation, which may become valuable for the development of treatments for ZNFX1 mutation-related diseases.

5.
Nature ; 602(7898): 657-663, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35016194

RESUMO

The SARS-CoV-2 B.1.1.529 (Omicron) variant contains 15 mutations of the receptor-binding domain (RBD). How Omicron evades RBD-targeted neutralizing antibodies requires immediate investigation. Here we use high-throughput yeast display screening1,2 to determine the profiles of RBD escaping mutations for 247 human anti-RBD neutralizing antibodies and show that the neutralizing antibodies can be classified by unsupervised clustering into six epitope groups (A-F)-a grouping that is highly concordant with knowledge-based structural classifications3-5. Various single mutations of Omicron can impair neutralizing antibodies of different epitope groups. Specifically, neutralizing antibodies in groups A-D, the epitopes of which overlap with the ACE2-binding motif, are largely escaped by K417N, G446S, E484A and Q493R. Antibodies in group E (for example, S309)6 and group F (for example, CR3022)7, which often exhibit broad sarbecovirus neutralizing activity, are less affected by Omicron, but a subset of neutralizing antibodies are still escaped by G339D, N440K and S371L. Furthermore, Omicron pseudovirus neutralization showed that neutralizing antibodies that sustained single mutations could also be escaped, owing to multiple synergetic mutations on their epitopes. In total, over 85% of the tested neutralizing antibodies were escaped by Omicron. With regard to neutralizing-antibody-based drugs, the neutralization potency of LY-CoV016, LY-CoV555, REGN10933, REGN10987, AZD1061, AZD8895 and BRII-196 was greatly undermined by Omicron, whereas VIR-7831 and DXP-604 still functioned at a reduced efficacy. Together, our data suggest that infection with Omicron would result in considerable humoral immune evasion, and that neutralizing antibodies targeting the sarbecovirus conserved region will remain most effective. Our results inform the development of antibody-based drugs and vaccines against Omicron and future variants.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Evasão da Resposta Imune/imunologia , Testes de Neutralização , SARS-CoV-2/imunologia , Enzima de Conversão de Angiotensina 2/metabolismo , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/uso terapêutico , Anticorpos Neutralizantes/classificação , Anticorpos Antivirais/classificação , COVID-19/imunologia , COVID-19/virologia , Vacinas contra COVID-19/imunologia , Células Cultivadas , Convalescença , Epitopos de Linfócito B/química , Epitopos de Linfócito B/imunologia , Humanos , Soros Imunes/imunologia , Modelos Moleculares , Mutação , SARS-CoV-2/química , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/metabolismo
6.
Nature ; 608(7923): 593-602, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35714668

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron sublineages BA.2.12.1, BA.4 and BA.5 exhibit higher transmissibility than the BA.2 lineage1. The receptor binding and immune-evasion capability of these recently emerged variants require immediate investigation. Here, coupled with structural comparisons of the spike proteins, we show that BA.2.12.1, BA.4 and BA.5 (BA.4 and BA.5 are hereafter referred collectively to as BA.4/BA.5) exhibit similar binding affinities to BA.2 for the angiotensin-converting enzyme 2 (ACE2) receptor. Of note, BA.2.12.1 and BA.4/BA.5 display increased evasion of neutralizing antibodies compared with BA.2 against plasma from triple-vaccinated individuals or from individuals who developed a BA.1 infection after vaccination. To delineate the underlying antibody-evasion mechanism, we determined the escape mutation profiles2, epitope distribution3 and Omicron-neutralization efficiency of 1,640 neutralizing antibodies directed against the receptor-binding domain of the viral spike protein, including 614 antibodies isolated from people who had recovered from BA.1 infection. BA.1 infection after vaccination predominantly recalls humoral immune memory directed against ancestral (hereafter referred to as wild-type (WT)) SARS-CoV-2 spike protein. The resulting elicited antibodies could neutralize both WT SARS-CoV-2 and BA.1 and are enriched on epitopes on spike that do not bind ACE2. However, most of these cross-reactive neutralizing antibodies are evaded by spike mutants L452Q, L452R and F486V. BA.1 infection can also induce new clones of BA.1-specific antibodies that potently neutralize BA.1. Nevertheless, these neutralizing antibodies are largely evaded by BA.2 and BA.4/BA.5 owing to D405N and F486V mutations, and react weakly to pre-Omicron variants, exhibiting narrow neutralization breadths. The therapeutic neutralizing antibodies bebtelovimab4 and cilgavimab5 can effectively neutralize BA.2.12.1 and BA.4/BA.5, whereas the S371F, D405N and R408S mutations undermine most broadly sarbecovirus-neutralizing antibodies. Together, our results indicate that Omicron may evolve mutations to evade the humoral immunity elicited by BA.1 infection, suggesting that BA.1-derived vaccine boosters may not achieve broad-spectrum protection against new Omicron variants.


Assuntos
Anticorpos Antivirais , Deriva e Deslocamento Antigênicos , COVID-19 , Epitopos de Linfócito B , Tolerância Imunológica , Mutação , SARS-CoV-2 , Enzima de Conversão de Angiotensina 2/metabolismo , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Deriva e Deslocamento Antigênicos/genética , Deriva e Deslocamento Antigênicos/imunologia , COVID-19/imunologia , COVID-19/transmissão , COVID-19/virologia , Vacinas contra COVID-19/imunologia , Epitopos de Linfócito B/química , Epitopos de Linfócito B/genética , Epitopos de Linfócito B/imunologia , Humanos , Imunidade Humoral , Imunização Secundária , Testes de Neutralização , SARS-CoV-2/classificação , SARS-CoV-2/genética , SARS-CoV-2/imunologia , SARS-CoV-2/metabolismo , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/metabolismo
7.
Mol Cell ; 79(2): 234-250.e9, 2020 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-32579944

RESUMO

Somatic cell nuclear transfer (SCNT) can reprogram a somatic nucleus to a totipotent state. However, the re-organization of 3D chromatin structure in this process remains poorly understood. Using low-input Hi-C, we revealed that, during SCNT, the transferred nucleus first enters a mitotic-like state (premature chromatin condensation). Unlike fertilized embryos, SCNT embryos show stronger topologically associating domains (TADs) at the 1-cell stage. TADs become weaker at the 2-cell stage, followed by gradual consolidation. Compartments A/B are markedly weak in 1-cell SCNT embryos and become increasingly strengthened afterward. By the 8-cell stage, somatic chromatin architecture is largely reset to embryonic patterns. Unexpectedly, we found cohesin represses minor zygotic genome activation (ZGA) genes (2-cell-specific genes) in pluripotent and differentiated cells, and pre-depleting cohesin in donor cells facilitates minor ZGA and SCNT. These data reveal multi-step reprogramming of 3D chromatin architecture during SCNT and support dual roles of cohesin in TAD formation and minor ZGA repression.


Assuntos
Proteínas de Ciclo Celular/fisiologia , Cromatina/fisiologia , Proteínas Cromossômicas não Histona/fisiologia , Técnicas de Transferência Nuclear , Zigoto/fisiologia , Animais , Linhagem Celular , Núcleo Celular , Montagem e Desmontagem da Cromatina , Biologia Computacional/métodos , Conjuntos de Dados como Assunto , Desenvolvimento Embrionário , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Coesinas
8.
N Engl J Med ; 390(20): 1862-1872, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38752650

RESUMO

BACKGROUND: Treatment of acute stroke, before a distinction can be made between ischemic and hemorrhagic types, is challenging. Whether very early blood-pressure control in the ambulance improves outcomes among patients with undifferentiated acute stroke is uncertain. METHODS: We randomly assigned patients with suspected acute stroke that caused a motor deficit and with elevated systolic blood pressure (≥150 mm Hg), who were assessed in the ambulance within 2 hours after the onset of symptoms, to receive immediate treatment to lower the systolic blood pressure (target range, 130 to 140 mm Hg) (intervention group) or usual blood-pressure management (usual-care group). The primary efficacy outcome was functional status as assessed by the score on the modified Rankin scale (range, 0 [no symptoms] to 6 [death]) at 90 days after randomization. The primary safety outcome was any serious adverse event. RESULTS: A total of 2404 patients (mean age, 70 years) in China underwent randomization and provided consent for the trial: 1205 in the intervention group and 1199 in the usual-care group. The median time between symptom onset and randomization was 61 minutes (interquartile range, 41 to 93), and the mean blood pressure at randomization was 178/98 mm Hg. Stroke was subsequently confirmed by imaging in 2240 patients, of whom 1041 (46.5%) had a hemorrhagic stroke. At the time of patients' arrival at the hospital, the mean systolic blood pressure in the intervention group was 159 mm Hg, as compared with 170 mm Hg in the usual-care group. Overall, there was no difference in functional outcome between the two groups (common odds ratio, 1.00; 95% confidence interval [CI], 0.87 to 1.15), and the incidence of serious adverse events was similar in the two groups. Prehospital reduction of blood pressure was associated with a decrease in the odds of a poor functional outcome among patients with hemorrhagic stroke (common odds ratio, 0.75; 95% CI, 0.60 to 0.92) but an increase among patients with cerebral ischemia (common odds ratio, 1.30; 95% CI, 1.06 to 1.60). CONCLUSIONS: In this trial, prehospital blood-pressure reduction did not improve functional outcomes in a cohort of patients with undifferentiated acute stroke, of whom 46.5% subsequently received a diagnosis of hemorrhagic stroke. (Funded by the National Health and Medical Research Council of Australia and others; INTERACT4 ClinicalTrials.gov number, NCT03790800; Chinese Trial Registry number, ChiCTR1900020534.).


Assuntos
Anti-Hipertensivos , Pressão Sanguínea , Serviços Médicos de Emergência , Hipertensão , Acidente Vascular Cerebral , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ambulâncias , Anti-Hipertensivos/administração & dosagem , Anti-Hipertensivos/efeitos adversos , Anti-Hipertensivos/uso terapêutico , Pressão Sanguínea/efeitos dos fármacos , Hipertensão/complicações , Hipertensão/tratamento farmacológico , AVC Isquêmico/terapia , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/terapia , Tempo para o Tratamento , Doença Aguda , Estado Funcional , China
9.
Nature ; 600(7887): 81-85, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34853456

RESUMO

Understanding the structure and dynamic process of water at the solid-liquid interface is an extremely important topic in surface science, energy science and catalysis1-3. As model catalysts, atomically flat single-crystal electrodes exhibit well-defined surface and electric field properties, and therefore may be used to elucidate the relationship between structure and electrocatalytic activity at the atomic level4,5. Hence, studying interfacial water behaviour on single-crystal surfaces provides a framework for understanding electrocatalysis6,7. However, interfacial water is notoriously difficult to probe owing to interference from bulk water and the complexity of interfacial environments8. Here, we use electrochemical, in situ Raman spectroscopic and computational techniques to investigate the interfacial water on atomically flat Pd single-crystal surfaces. Direct spectral evidence reveals that interfacial water consists of hydrogen-bonded and hydrated Na+ ion water. At hydrogen evolution reaction (HER) potentials, dynamic changes in the structure of interfacial water were observed from a random distribution to an ordered structure due to bias potential and Na+ ion cooperation. Structurally ordered interfacial water facilitated high-efficiency electron transfer across the interface, resulting in higher HER rates. The electrolytes and electrode surface effects on interfacial water were also probed and found to affect water structure. Therefore, through local cation tuning strategies, we anticipate that these results may be generalized to enable ordered interfacial water to improve electrocatalytic reaction rates.

10.
Nature ; 595(7865): 48-52, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34194017

RESUMO

One of the first theoretically predicted manifestations of strong interactions in many-electron systems was the Wigner crystal1-3, in which electrons crystallize into a regular lattice. The crystal can melt via either thermal or quantum fluctuations4. Quantum melting of the Wigner crystal is predicted to produce exotic intermediate phases5,6 and quantum magnetism7,8 because of the intricate interplay of Coulomb interactions and kinetic energy. However, studying two-dimensional Wigner crystals in the quantum regime has often required a strong magnetic field9-11 or a moiré superlattice potential12-15, thus limiting access to the full phase diagram of the interacting electron liquid. Here we report the observation of bilayer Wigner crystals without magnetic fields or moiré potentials in an atomically thin transition metal dichalcogenide heterostructure, which consists of two MoSe2 monolayers separated by hexagonal boron nitride. We observe optical signatures of robust correlated insulating states at symmetric (1:1) and asymmetric (3:1, 4:1 and 7:1) electron doping of the two MoSe2 layers at cryogenic temperatures. We attribute these features to bilayer Wigner crystals composed of two interlocked commensurate triangular electron lattices, stabilized by inter-layer interaction16. The Wigner crystal phases are remarkably stable, and undergo quantum and thermal melting transitions at electron densities of up to 6 × 1012 per square centimetre and at temperatures of up to about 40 kelvin. Our results demonstrate that an atomically thin heterostructure is a highly tunable platform for realizing many-body electronic states and probing their liquid-solid and magnetic quantum phase transitions4-8,17.

11.
Mol Cell ; 73(3): 547-561.e6, 2019 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-30735655

RESUMO

Chromatin organization undergoes drastic reconfiguration during gametogenesis. However, the molecular reprogramming of three-dimensional chromatin structure in this process remains poorly understood for mammals, including primates. Here, we examined three-dimensional chromatin architecture during spermatogenesis in rhesus monkey using low-input Hi-C. Interestingly, we found that topologically associating domains (TADs) undergo dissolution and reestablishment in spermatogenesis. Strikingly, pachytene spermatocytes, where synapsis occurs, are strongly depleted for TADs despite their active transcription state but uniquely show highly refined local compartments that alternate between transcribing and non-transcribing regions (refined-A/B). Importantly, such chromatin organization is conserved in mouse, where it remains largely intact upon transcription inhibition. Instead, it is attenuated in mutant spermatocytes, where the synaptonemal complex failed to be established. Intriguingly, this is accompanied by the restoration of TADs, suggesting that the synaptonemal complex may restrict TADs and promote local compartments. Thus, these data revealed extensive reprogramming of higher-order meiotic chromatin architecture during mammalian gametogenesis.


Assuntos
Reprogramação Celular , Montagem e Desmontagem da Cromatina , Cromatina/metabolismo , Meiose , Espermatogênese , Espermatozoides/metabolismo , Animais , Cromatina/química , Cromatina/genética , Regulação da Expressão Gênica no Desenvolvimento , Células HCT116 , Humanos , Macaca mulatta , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Conformação de Ácido Nucleico , Estágio Paquíteno , Conformação Proteica , Relação Estrutura-Atividade , Fatores de Tempo , Transcrição Gênica , Inativação do Cromossomo X
12.
Proc Natl Acad Sci U S A ; 121(35): e2400446121, 2024 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-39150777

RESUMO

The emergence of carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKp) is a growing concern due to its high mortality and limited treatment options. Although hypermucoviscosity is crucial for CR-hvKp infection, the role of changes in bacterial mucoviscosity in the host colonization and persistence of CR-hvKp is not clearly defined. Herein, we observed a phenotypic switch of CR-hvKp from a hypermucoviscous to a hypomucoviscous state in a patient with scrotal abscess and urinary tract infection (UTI). This switch was attributed to decreased expression of rmpADC, the regulator of mucoid phenotype, caused by deletion of the upstream insertion sequence ISKpn26. Postswitching, the hypomucoid variant showed a 9.0-fold decrease in mice sepsis mortality, a >170.0-fold reduction in the ability to evade macrophage phagocytosis in vitro, and an 11.2- to 40.9-fold drop in growth rate in normal mouse serum. Conversely, it exhibited an increased residence time in the mouse urinary tract (21 vs. 6 d), as well as a 216.4-fold boost in adhesion to bladder epithelial cells and a 48.7% enhancement in biofilm production. Notably, the CR-hvKp mucoid switch was reproduced in an antibiotic-free mouse UTI model. The in vivo generation of hypomucoid variants was primarily associated with defective or low expression of rmpADC or capsule synthesis gene wcaJ, mediated by ISKpn26 insertion/deletion or base-pair insertion. The spontaneous hypomucoid variants also outcompeted hypermucoid bacteria in the mouse urinary tract. Collectively, the ISKpn26-associated mucoid switch in CR-hvKp signifies the antibiotic-independent host adaptive evolution, providing insights into the role of mucoid switch in the persistence of CR-hvKp.


Assuntos
Carbapenêmicos , Infecções por Klebsiella , Klebsiella pneumoniae , Infecções Urinárias , Klebsiella pneumoniae/patogenicidade , Klebsiella pneumoniae/genética , Animais , Humanos , Infecções por Klebsiella/microbiologia , Infecções Urinárias/microbiologia , Camundongos , Carbapenêmicos/farmacologia , Masculino , Virulência/genética , Antibacterianos/farmacologia , Sistema Urinário/microbiologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo
13.
PLoS Pathog ; 20(9): e1012594, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39348396

RESUMO

Coxsackievirus B (CVB) is the major causative pathogen for severe diseases such as viral myocarditis, meningitis, and pancreatitis. There is no effective antiviral therapy currently available for CVB infection primarily due to that the pathogenesis of CVB has not been completely understood. Viruses are obligate intracellular pathogens which subvert cellular processes to ensure viral replication. Dysregulation of ubiquitination has been implicated in CVB infection. However, how ubiquitination is involved in CVB infection remains unclear. Here we found that the 3D protein of CVB3, the RNA-dependent RNA polymerase, was modified at K220 by K48-linked polyubiquitination which promoted its degradation through proteasome. Proteomic analysis showed that the E3 ligase TRIM56 was upregulated in CVB3-infected cells, while the majority of TRIMs remained unchanged. Pull-down and immunoprecipitation analyses showed that TRIM56 interacted with CVB3 3D. Immunofluorescence observation showed that viral 3D protein was colocalized with TRIM56. TRIM56 overexpression resulted in enhanced ubiquitination of CVB3 3D and decreased virus yield. Moreover, TRIM56 was cleaved by viral 3C protease in CVB3-infected cells. Taken together, this study demonstrated that TRIM56 mediates the ubiquitination and proteasomal degradation of the CVB3 3D protein. These findings demonstrate that TRIM56 is an intrinsic cellular restriction factor against CVB infection, and enhancing viral protein degradation could be a potential strategy to control CVB infection.


Assuntos
Infecções por Coxsackievirus , Enterovirus Humano B , RNA Polimerase Dependente de RNA , Proteínas com Motivo Tripartido , Ubiquitina-Proteína Ligases , Ubiquitinação , Humanos , Enterovirus Humano B/fisiologia , Ubiquitina-Proteína Ligases/metabolismo , Proteínas com Motivo Tripartido/metabolismo , Infecções por Coxsackievirus/metabolismo , Infecções por Coxsackievirus/virologia , RNA Polimerase Dependente de RNA/metabolismo , Replicação Viral/fisiologia , Células HeLa , Proteínas Virais/metabolismo , Proteínas Virais/genética
14.
Plant Cell ; 35(11): 4133-4154, 2023 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-37542517

RESUMO

Phytohormones play indispensable roles in plant growth and development. However, the molecular mechanisms underlying phytohormone-mediated regulation of fiber secondary cell wall (SCW) formation in cotton (Gossypium hirsutum) remain largely underexplored. Here, we provide mechanistic evidence for functional interplay between the APETALA2/ethylene response factor (AP2/ERF) transcription factor GhERF108 and auxin response factors GhARF7-1 and GhARF7-2 in dictating the ethylene-auxin signaling crosstalk that regulates fiber SCW biosynthesis. Specifically, in vitro cotton ovule culture revealed that ethylene and auxin promote fiber SCW deposition. GhERF108 RNA interference (RNAi) cotton displayed remarkably reduced cell wall thickness compared with controls. GhERF108 interacted with GhARF7-1 and GhARF7-2 to enhance the activation of the MYB transcription factor gene GhMYBL1 (MYB domain-like protein 1) in fibers. GhARF7-1 and GhARF7-2 respond to auxin signals that promote fiber SCW thickening. GhMYBL1 RNAi and GhARF7-1 and GhARF7-2 virus-induced gene silencing (VIGS) cotton displayed similar defects in fiber SCW formation as GhERF108 RNAi cotton. Moreover, the ethylene and auxin responses were reduced in GhMYBL1 RNAi plants. GhMYBL1 directly binds to the promoters of GhCesA4-1, GhCesA4-2, and GhCesA8-1 and activates their expression to promote cellulose biosynthesis, thereby boosting fiber SCW formation. Collectively, our findings demonstrate that the collaboration between GhERF108 and GhARF7-1 or GhARF7-2 establishes ethylene-auxin signaling crosstalk to activate GhMYBL1, ultimately leading to the activation of fiber SCW biosynthesis.


Assuntos
Fibra de Algodão , Fatores de Transcrição , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Ácidos Indolacéticos/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Regulação da Expressão Gênica de Plantas , Gossypium/genética , Gossypium/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Etilenos/metabolismo , Parede Celular/metabolismo
15.
Nat Chem Biol ; 20(3): 344-352, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38052959

RESUMO

Compact Cas9 nucleases hold great promise for therapeutic applications. Although several compact Cas9 nucleases have been developed, many genomic loci still could not be edited due to a lack of protospacer adjacent motifs (PAMs). We previously developed a compact SlugCas9 recognizing an NNGG PAM. Here we demonstrate that SlugCas9 displays comparable activity to SpCas9. We developed a simple phage-assisted evolution to engineer SlugCas9 for unique PAM requirements. Interestingly, we generated a SlugCas9 variant (SlugCas9-NNG) that could recognize an NNG PAM, expanding the targeting scope. We further developed a SlugCas9-NNG-based adenine base editor and demonstrated that it could be delivered by a single adeno-associated virus to disrupt PCSK9 splice donor and splice acceptor. These genome editors greatly enhance our ability for in vivo genome editing.


Assuntos
Bacteriófagos , Sistemas CRISPR-Cas , Sistemas CRISPR-Cas/genética , Pró-Proteína Convertase 9 , Adenina , Endonucleases/genética
16.
PLoS Biol ; 21(10): e3002313, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37796762

RESUMO

Mutations in mitochondrial DNA (mtDNA) contribute to a variety of serious multi-organ human diseases, which are strictly inherited from the maternal germline. However, there is currently no curative treatment. Attention has been focused on preventing the transmission of mitochondrial diseases through mitochondrial replacement (MR) therapy, but levels of mutant mtDNA can often unexpectedly undergo significant changes known as mitochondrial genetic drift. Here, we proposed a novel strategy to perform spindle-chromosomal complex transfer (SCCT) with maximal residue removal (MRR) in metaphase II (MII) oocytes, thus hopefully eliminated the transmission of mtDNA diseases. With the MRR procedure, we initially investigated the proportions of mtDNA copy numbers in isolated karyoplasts to those of individual oocytes. Spindle-chromosomal morphology and copy number variation (CNV) analysis also confirmed the safety of this method. Then, we reconstructed oocytes by MRR-SCCT, which well developed to blastocysts with minimal mtDNA residue and normal chromosomal copy numbers. Meanwhile, we optimized the manipulation order between intracytoplasmic sperm injection (ICSI) and SCC transfer and concluded that ICSI-then-transfer was conducive to avoid premature activation of reconstructed oocytes in favor of normal fertilization. Offspring of mice generated by embryos transplantation in vivo and embryonic stem cells derivation further presented evidences for competitive development competence and stable mtDNA carryover without genetic drift. Importantly, we also successfully accomplished SCCT in human MII oocytes resulting in tiny mtDNA residue and excellent embryo development through MRR manipulation. Taken together, our preclinical mouse and human models of the MRR-SCCT strategy not only demonstrated efficient residue removal but also high compatibility with normal embryo development, thus could potentially be served as a feasible clinical treatment to prevent the transmission of inherited mtDNA diseases.


Assuntos
Variações do Número de Cópias de DNA , Doenças Mitocondriais , Masculino , Humanos , Animais , Camundongos , Variações do Número de Cópias de DNA/genética , Sêmen , Mitocôndrias/genética , DNA Mitocondrial/genética , DNA Mitocondrial/análise , Doenças Mitocondriais/genética , Doenças Mitocondriais/prevenção & controle , Oócitos
17.
Chem Rev ; 124(6): 3494-3589, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38478597

RESUMO

The renewable energy industry demands rechargeable batteries that can be manufactured at low cost using abundant resources while offering high energy density, good safety, wide operating temperature windows, and long lifespans. Utilizing fluorine chemistry to redesign battery configurations/components is considered a critical strategy to fulfill these requirements due to the natural abundance, robust bond strength, and extraordinary electronegativity of fluorine and the high free energy of fluoride formation, which enables the fluorinated components with cost effectiveness, nonflammability, and intrinsic stability. In particular, fluorinated materials and electrode|electrolyte interphases have been demonstrated to significantly affect reaction reversibility/kinetics, safety, and temperature tolerance of rechargeable batteries. However, the underlining principles governing material design and the mechanistic insights of interphases at the atomic level have been largely overlooked. This review covers a wide range of topics from the exploration of fluorine-containing electrodes, fluorinated electrolyte constituents, and other fluorinated battery components for metal-ion shuttle batteries to constructing fluoride-ion batteries, dual-ion batteries, and other new chemistries. In doing so, this review aims to provide a comprehensive understanding of the structure-property interactions, the features of fluorinated interphases, and cutting-edge techniques for elucidating the role of fluorine chemistry in rechargeable batteries. Further, we present current challenges and promising strategies for employing fluorine chemistry, aiming to advance the electrochemical performance, wide temperature operation, and safety attributes of rechargeable batteries.

18.
Mol Cell ; 69(2): 279-291.e5, 2018 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-29351847

RESUMO

Sustained energy starvation leads to activation of AMP-activated protein kinase (AMPK), which coordinates energy status with numerous cellular processes including metabolism, protein synthesis, and autophagy. Here, we report that AMPK phosphorylates the histone methyltransferase EZH2 at T311 to disrupt the interaction between EZH2 and SUZ12, another core component of the polycomb repressive complex 2 (PRC2), leading to attenuated PRC2-dependent methylation of histone H3 at Lys27. As such, PRC2 target genes, many of which are known tumor suppressors, were upregulated upon T311-EZH2 phosphorylation, which suppressed tumor cell growth both in cell culture and mouse xenografts. Pathologically, immunohistochemical analyses uncovered a positive correlation between AMPK activity and pT311-EZH2, and higher pT311-EZH2 correlates with better survival in both ovarian and breast cancer patients. Our finding suggests that AMPK agonists might be promising sensitizers for EZH2-targeting cancer therapies.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Animais , Carcinogênese/genética , Ciclo Celular , Linhagem Celular Tumoral , Proliferação de Células , Metilação de DNA , Proteínas de Ligação a DNA/metabolismo , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Proteína Potenciadora do Homólogo 2 de Zeste/fisiologia , Epigênese Genética , Feminino , Histonas/metabolismo , Humanos , Camundongos , Proteínas de Neoplasias , Proteínas Nucleares/metabolismo , Oncogenes , Neoplasias Ovarianas/metabolismo , Fosforilação , Complexo Repressor Polycomb 2/metabolismo , Complexo Repressor Polycomb 2/fisiologia , Fatores de Transcrição , Regulação para Cima
19.
Proc Natl Acad Sci U S A ; 120(42): e2300255120, 2023 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-37819985

RESUMO

Speech production is a complex human function requiring continuous feedforward commands together with reafferent feedback processing. These processes are carried out by distinct frontal and temporal cortical networks, but the degree and timing of their recruitment and dynamics remain poorly understood. We present a deep learning architecture that translates neural signals recorded directly from the cortex to an interpretable representational space that can reconstruct speech. We leverage learned decoding networks to disentangle feedforward vs. feedback processing. Unlike prevailing models, we find a mixed cortical architecture in which frontal and temporal networks each process both feedforward and feedback information in tandem. We elucidate the timing of feedforward and feedback-related processing by quantifying the derived receptive fields. Our approach provides evidence for a surprisingly mixed cortical architecture of speech circuitry together with decoding advances that have important implications for neural prosthetics.


Assuntos
Fala , Lobo Temporal , Humanos , Retroalimentação , Estimulação Acústica
20.
Proc Natl Acad Sci U S A ; 120(17): e2221688120, 2023 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-37071679

RESUMO

The excitonic insulator is an electronically driven phase of matter that emerges upon the spontaneous formation and Bose condensation of excitons. Detecting this exotic order in candidate materials is a subject of paramount importance, as the size of the excitonic gap in the band structure establishes the potential of this collective state for superfluid energy transport. However, the identification of this phase in real solids is hindered by the coexistence of a structural order parameter with the same symmetry as the excitonic order. Only a few materials are currently believed to host a dominant excitonic phase, Ta2NiSe5 being the most promising. Here, we test this scenario by using an ultrashort laser pulse to quench the broken-symmetry phase of this transition metal chalcogenide. Tracking the dynamics of the material's electronic and crystal structure after light excitation reveals spectroscopic fingerprints that are compatible only with a primary order parameter of phononic nature. We rationalize our findings through state-of-the-art calculations, confirming that the structural order accounts for most of the gap opening. Our results suggest that the spontaneous symmetry breaking in Ta2NiSe5 is mostly of structural character, hampering the possibility to realize quasi-dissipationless energy transport.

SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa