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1.
Immunity ; 56(12): 2773-2789.e8, 2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-37992711

RESUMO

Although the gut microbiota can influence central nervous system (CNS) autoimmune diseases, the contribution of the intestinal epithelium to CNS autoimmunity is less clear. Here, we showed that intestinal epithelial dopamine D2 receptors (IEC DRD2) promoted sex-specific disease progression in an animal model of multiple sclerosis. Female mice lacking Drd2 selectively in intestinal epithelial cells showed a blunted inflammatory response in the CNS and reduced disease progression. In contrast, overexpression or activation of IEC DRD2 by phenylethylamine administration exacerbated disease severity. This was accompanied by altered lysozyme expression and gut microbiota composition, including reduced abundance of Lactobacillus species. Furthermore, treatment with N2-acetyl-L-lysine, a metabolite derived from Lactobacillus, suppressed microglial activation and neurodegeneration. Taken together, our study indicates that IEC DRD2 hyperactivity impacts gut microbial abundances and increases susceptibility to CNS autoimmune diseases in a female-biased manner, opening up future avenues for sex-specific interventions of CNS autoimmune diseases.


Assuntos
Doenças Autoimunes do Sistema Nervoso , Esclerose Múltipla , Masculino , Feminino , Camundongos , Animais , Esclerose Múltipla/metabolismo , Modelos Animais de Doenças , Transdução de Sinais , Progressão da Doença , Receptores Dopaminérgicos
2.
Nat Immunol ; 18(10): 1104-1116, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28825701

RESUMO

Cross-regulation of Toll-like receptor (TLR) responses by cytokines is essential for effective host defense, avoidance of toxicity and homeostasis, but the underlying mechanisms are not well understood. Our comprehensive epigenomics approach to the analysis of human macrophages showed that the proinflammatory cytokines TNF and type I interferons induced transcriptional cascades that altered chromatin states to broadly reprogram responses induced by TLR4. TNF tolerized genes encoding inflammatory molecules to prevent toxicity while preserving the induction of genes encoding antiviral and metabolic molecules. Type I interferons potentiated the inflammatory function of TNF by priming chromatin to prevent the silencing of target genes of the transcription factor NF-κB that encode inflammatory molecules. The priming of chromatin enabled robust transcriptional responses to weak upstream signals. Similar chromatin regulation occurred in human diseases. Our findings reveal that signaling crosstalk between interferons and TNF is integrated at the level of chromatin to reprogram inflammatory responses, and identify previously unknown functions and mechanisms of action of these cytokines.


Assuntos
Epigênese Genética , Inflamação/etiologia , Inflamação/metabolismo , Interferon Tipo I/metabolismo , Macrófagos/imunologia , Macrófagos/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Sítios de Ligação , Montagem e Desmontagem da Cromatina , Imunoprecipitação da Cromatina , Análise por Conglomerados , Biologia Computacional/métodos , Citocinas/genética , Citocinas/metabolismo , Epigenômica/métodos , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Lipopolissacarídeos/imunologia , Lúpus Eritematoso Sistêmico/genética , Lúpus Eritematoso Sistêmico/imunologia , Lúpus Eritematoso Sistêmico/metabolismo , Monócitos/imunologia , Monócitos/metabolismo , Motivos de Nucleotídeos , Regiões Promotoras Genéticas , Ligação Proteica , Transporte Proteico , Transdução de Sinais , Receptor 4 Toll-Like/metabolismo , Fatores de Transcrição/metabolismo
3.
Nature ; 621(7977): 75-81, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37673990

RESUMO

Benefiting from high energy density (2,600 Wh kg-1) and low cost, lithium-sulfur (Li-S) batteries are considered promising candidates for advanced energy-storage systems1-4. Despite tremendous efforts in suppressing the long-standing shuttle effect of lithium polysulfides5-7, understanding of the interfacial reactions of lithium polysulfides at the nanoscale remains elusive. This is mainly because of the limitations of in situ characterization tools in tracing the liquid-solid conversion of unstable lithium polysulfides at high temporal-spatial resolution8-10. There is an urgent need to understand the coupled phenomena inside Li-S batteries, specifically, the dynamic distribution, aggregation, deposition and dissolution of lithium polysulfides. Here, by using in situ liquid-cell electrochemical transmission electron microscopy, we directly visualized the transformation of lithium polysulfides over electrode surfaces at the atomic scale. Notably, an unexpected gathering-induced collective charge transfer of lithium polysulfides was captured on the nanocluster active-centre-immobilized surface. It further induced an instantaneous deposition of nonequilibrium Li2S nanocrystals from the dense liquid phase of lithium polysulfides. Without mediation of active centres, the reactions followed a classical single-molecule pathway, lithium polysulfides transforming into Li2S2 and Li2S step by step. Molecular dynamics simulations indicated that the long-range electrostatic interaction between active centres and lithium polysulfides promoted the formation of a dense phase consisting of Li+ and Sn2- (2 < n ≤ 6), and the collective charge transfer in the dense phase was further verified by ab initio molecular dynamics simulations. The collective interfacial reaction pathway unveils a new transformation mechanism and deepens the fundamental understanding of Li-S batteries.

4.
Nat Immunol ; 17(8): 930-7, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27322654

RESUMO

Most of the known regulatory mechanisms that curb inflammatory gene expression target pre-transcription-initiation steps, and evidence for post-initiation regulation of inflammatory gene expression remains scarce. We found that the transcriptional repressor Hes1 suppressed production of CXCL1, a chemokine that is crucial for recruiting neutrophils. Hes1 negatively regulated neutrophil recruitment in vivo in a manner that was dependent on macrophage-produced CXCL1, and it attenuated the severity of inflammatory arthritis. Mechanistically, inhibition of Cxcl1 expression by Hes1 did not involve modification of transcription initiation. Instead, Hes1 inhibited signal-induced recruitment of the positive transcription-elongation complex P-TEFb and thereby prevented phosphorylation of RNA polymerase II at Ser2 and productive elongation. Thus, our results identify Hes1 as a homeostatic suppressor of inflammatory responses that exerts its suppressive function by regulating transcription elongation.


Assuntos
Artrite/genética , Proteínas de Ciclo Celular/metabolismo , Inflamação/genética , Macrófagos/imunologia , Fatores de Transcrição HES-1/metabolismo , Animais , Proteínas de Ciclo Celular/genética , Células Cultivadas , Quimiocina CXCL1/genética , Quimiocina CXCL1/metabolismo , Regulação da Expressão Gênica/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mutação/genética , Infiltração de Neutrófilos/genética , Fator B de Elongação Transcricional Positiva/genética , Fator B de Elongação Transcricional Positiva/metabolismo , RNA Polimerase II/metabolismo , Elongação da Transcrição Genética , Fatores de Transcrição HES-1/genética
5.
Immunity ; 47(2): 235-250.e4, 2017 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-28813657

RESUMO

Mechanisms by which interferon (IFN)-γ activates genes to promote macrophage activation are well studied, but little is known about mechanisms and functions of IFN-γ-mediated gene repression. We used an integrated transcriptomic and epigenomic approach to analyze chromatin accessibility, histone modifications, transcription-factor binding, and gene expression in IFN-γ-primed human macrophages. IFN-γ suppressed basal expression of genes corresponding to an "M2"-like homeostatic and reparative phenotype. IFN-γ repressed genes by suppressing the function of enhancers enriched for binding by transcription factor MAF. Mechanistically, IFN-γ disassembled a subset of enhancers by inducing coordinate suppression of binding by MAF, lineage-determining transcription factors, and chromatin accessibility. Genes associated with MAF-binding enhancers were suppressed in macrophages isolated from rheumatoid-arthritis patients, revealing a disease-associated signature of IFN-γ-mediated repression. These results identify enhancer inactivation and disassembly as a mechanism of IFN-γ-mediated gene repression and reveal that MAF regulates the macrophage enhancer landscape and is suppressed by IFN-γ to augment macrophage activation.


Assuntos
Artrite Reumatoide/imunologia , Montagem e Desmontagem da Cromatina , Interferon gama/metabolismo , Macrófagos/imunologia , Proteínas Proto-Oncogênicas c-maf/metabolismo , Diferenciação Celular , Linhagem da Célula , Células Cultivadas , Citocinas/metabolismo , Elementos Facilitadores Genéticos/genética , Regulação da Expressão Gênica , Histonas/metabolismo , Humanos , Ligação Proteica , Proteínas Proto-Oncogênicas c-maf/genética , Transcriptoma
7.
Immunity ; 47(1): 66-79.e5, 2017 07 18.
Artigo em Inglês | MEDLINE | ID: mdl-28723554

RESUMO

Hypoxia augments inflammatory responses and osteoclastogenesis by incompletely understood mechanisms. We identified COMMD1 as a cell-intrinsic negative regulator of osteoclastogenesis that is suppressed by hypoxia. In human macrophages, COMMD1 restrained induction of NF-κB signaling and a transcription factor E2F1-dependent metabolic pathway by the cytokine RANKL. Downregulation of COMMD1 protein expression by hypoxia augmented RANKL-induced expression of inflammatory and E2F1 target genes and downstream osteoclastogenesis. E2F1 targets included glycolysis and metabolic genes including CKB that enabled cells to meet metabolic demands in challenging environments, as well as inflammatory cytokine-driven target genes. Expression quantitative trait locus analysis linked increased COMMD1 expression with decreased bone erosion in rheumatoid arthritis. Myeloid deletion of Commd1 resulted in increased osteoclastogenesis in arthritis and inflammatory osteolysis models. These results identify COMMD1 and an E2F-metabolic pathway as key regulators of osteoclastogenic responses under pathological inflammatory conditions and provide a mechanism by which hypoxia augments inflammation and bone destruction.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Artrite Reumatoide/imunologia , Macrófagos/imunologia , Osteogênese/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Células Cultivadas , Modelos Animais de Doenças , Fator de Transcrição E2F1/metabolismo , Feminino , Humanos , Hipóxia/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade , NF-kappa B/metabolismo , RNA Interferente Pequeno/genética , Transdução de Sinais
8.
Brief Bioinform ; 24(1)2023 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-36562723

RESUMO

Directed protein evolution applies repeated rounds of genetic mutagenesis and phenotypic screening and is often limited by experimental throughput. Through in silico prioritization of mutant sequences, machine learning has been applied to reduce wet lab burden to a level practical for human researchers. On the other hand, robotics permits large batches and rapid iterations for protein engineering cycles, but such capacities have not been well exploited in existing machine learning-assisted directed evolution approaches. Here, we report a scalable and batched method, Bayesian Optimization-guided EVOlutionary (BO-EVO) algorithm, to guide multiple rounds of robotic experiments to explore protein fitness landscapes of combinatorial mutagenesis libraries. We first examined various design specifications based on an empirical landscape of protein G domain B1. Then, BO-EVO was successfully generalized to another empirical landscape of an Escherichia coli kinase PhoQ, as well as simulated NK landscapes with up to moderate epistasis. This approach was then applied to guide robotic library creation and screening to engineer enzyme specificity of RhlA, a key biosynthetic enzyme for rhamnolipid biosurfactants. A 4.8-fold improvement in producing a target rhamnolipid congener was achieved after examining less than 1% of all possible mutants after four iterations. Overall, BO-EVO proves to be an efficient and general approach to guide combinatorial protein engineering without prior knowledge.


Assuntos
Engenharia de Proteínas , Proteínas , Humanos , Teorema de Bayes , Proteínas/genética , Evolução Biológica , Algoritmos
9.
J Cell Biochem ; 125(3): e30522, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38224175

RESUMO

Understanding the connection between senescence phenotypes and mitochondrial dysfunction is crucial in aging and premature aging diseases. Loss of mitochondrial function leads to a decline in T cell function, which plays a significant role in this process. However, more research is required to determine if improving mitochondrial homeostasis alleviates senescence phenotypes. Our research has shown an association between NAD+ and senescent T cells through the cGAS-STING pathway, which can lead to an inflammatory phenotype. Further research is needed to fully understand the role of NAD+ in T-cell aging and how it can be utilized to improve mitochondrial homeostasis and alleviate senescence phenotypes. We demonstrate here that mitochondrial dysfunction and cellular senescence with a senescence-associated secretory phenotype (SASP) occur in senescent T cells and tumor-bearing mice. Senescence is mediated by a stimulator of interferon genes (STING) and involves ectopic cytoplasmic DNA. We further show that boosting intracellular NAD+ levels with nicotinamide mononucleotide (NMN) prevents senescence and SASP by promoting mitophagy. NMN treatment also suppresses senescence and neuroinflammation and improves the survival cycle of mice. Encouraging mitophagy may be a useful strategy to prevent CD8+ T cells from senescence due to mitochondrial dysfunction. Additionally, supplementing with NMN to increase NAD+ levels could enhance survival rates in mice while also reducing senescence and inflammation, and enhancing mitophagy as a potential therapeutic intervention.


Assuntos
Doenças Mitocondriais , NAD , Camundongos , Animais , NAD/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Mitocôndrias/metabolismo , Senescência Celular/fisiologia , Homeostase , Doenças Mitocondriais/metabolismo , Suplementos Nutricionais
10.
J Am Chem Soc ; 146(25): 17103-17113, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38869216

RESUMO

Understanding the interfacial hydrogen evolution reaction (HER) is crucial to regulate the electrochemical behavior in aqueous zinc batteries. However, the mechanism of HER related to solvation chemistry remains elusive, especially the time-dependent dynamic evolution of the hydrogen bond (H-bond) under an electric field. Herein, we combine in situ spectroscopy with molecular dynamics simulation to unravel the dynamic evolution of the interfacial solvation structure. We find two critical change processes involving Zn-electroplating/stripping, including the initial electric double layer establishment to form an H2O-rich interface (abrupt change) and the subsequent dynamic evolution of an H-bond (gradual change). Moreover, the number of H-bonds increases, and their strength weakens in comparison with the bulk electrolyte under bias potential during Zn2+ desolvation, forming a diluted interface, resulting in massive hydrogen production. On the contrary, a concentrated interface (H-bond number decreases and strength enhances) is formed and produces a small amount of hydrogen during Zn2+ solvation. The insights on the above results contribute to deciphering the H-bond evolution with competition/corrosion HER during Zn-electroplating/stripping and clarifying the essence of electrochemical window widened and HER suppression by high concentration. This work presents a new strategy for aqueous electrolyte regulation by benchmarking the abrupt change of the interfacial state under an electric field as a zinc performance-enhancement criterion.

11.
J Am Chem Soc ; 146(7): 4557-4569, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38345667

RESUMO

Intelligent utilization of the anionic redox reaction (ARR) in Li-rich cathodes is an advanced strategy for the practical implementation of next-generation high-energy-density rechargeable batteries. However, due to the intrinsic complexity of ARR (e.g., nucleophilic attacks), the instability of the cathode-electrolyte interphase (CEI) on a Li-rich cathode presents more challenges than typical high-voltage cathodes. Here, we manipulate CEI interfacial engineering by introducing an all-fluorinated electrolyte and exploiting its interaction with the nucleophilic attack to construct a gradient CEI containing a pair of fluorinated layers on a Li-rich cathode, delivering enhanced interfacial stability. Negative/detrimental nucleophilic electrolyte decomposition has been efficiently evolved to further reinforce CEI fabrication, resulting in the construction of LiF-based indurated outer shield and fluorinated polymer-based flexible inner sheaths. Gradient interphase engineering dramatically improved the capacity retention of the Li-rich cathode from 43 to 71% after 800 cycles and achieved superior cycling stability in anode-free and pouch-type full cells (98.8% capacity retention, 220 cycles), respectively.

12.
Small ; 20(25): e2310341, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38225705

RESUMO

The safety, low cost, and high power density of aqueous Zn-based devices (AZDs) appeal to large-scale energy storage. Yet, the presence of hydrogen evolution reaction (HER) and chemical corrosion in the AZDs leads to local OH- concentration increasement and the formation of ZnxSOy(OH)z•nH2O (ZHS) by-products at the Zn/electrolyte interface, causing instability and irreversibility of the Zn-anodes. Here, a strategy is proposed to regulate OH- by introducing a bio-sourced/renewable polypeptide (ɛ-PL) as a pH regulator in electrolyte. The consumption of OH- species is evaluated through in vitro titration and cell in vivo in situ attenuated total reflection surface-enhanced infrared absorption spectroscopy at a macroscopic and molecular level. The introduction of ɛ-PL is found to significantly suppress the formation of ZHS and associated side reactions, and reduce the local coordinated H2O of the Zn2+ solvation shell, widening electrochemical stable window and suppressing OH- generation during HER. As a result, the inclusion of ɛ-PL improves the cycle time of Zn/Zn symmetrical cells from 15 to 225 h and enhances the cycle time of aqueous Zn- I2 cells to 1650 h compared to those with pristine electrolytes. This work highlights the potential of kinetical OH- regulation for by-product and dendrite-free AZDs.

13.
Hepatology ; 77(6): 1929-1942, 2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-35921500

RESUMO

BACKGROUND AND AIMS: Gain-of-function (GOF) mutations of CTNNB1 and loss-of-function (LOF) mutations of AXIN1 are recurrent genetic alterations in hepatocellular carcinoma (HCC). We aim to investigate the functional contribution of Hippo/YAP/TAZ in GOF CTNNB1 or LOF AXIN1 mutant HCCs. APPROACH AND RESULTS: The requirement of YAP/TAZ in c-Met/ß-Catenin and c-Met/sgAxin1-driven HCC was analyzed using conditional Yap , Taz , and Yap;Taz knockout (KO) mice. Mechanisms of AXIN1 in regulating YAP/TAZ were investigated using AXIN1 mutated HCC cells. Hepatocyte-specific inducible TTR-CreER T2KO system was applied to evaluate the role of Yap;Taz during tumor progression. Cabozantinib and G007-LK combinational treatment were tested in vitro and in vivo . Nuclear YAP/TAZ was strongly induced in c-Met/sgAxin1 mouse HCC cells. Activation of Hippo via overexpression of Lats2 or concomitant deletion of Yap and Taz significantly inhibited c-Met/sgAxin1 driven HCC development, whereas the same approaches had mild effects in c-Met/ß-Catenin HCCs. YAP is the major Hippo effector in c-Met/ß-Catenin HCCs, and both YAP and TAZ are required for c-Met/sgAxin1-dependent hepatocarcinogenesis. Mechanistically, AXIN1 binds to YAP/TAZ in human HCC cells and regulates YAP/TAZ stability. Genetic deletion of YAP/TAZ suppresses already formed c-Met/sgAxin1 liver tumors, supporting the requirement of YAP/TAZ during tumor progression. Importantly, tankyrase inhibitor G007-LK, which targets Hippo and Wnt pathways, synergizes with cabozantinib, a c-MET inhibitor, leading to tumor regression in the c-Met/sgAxin1 HCC model. CONCLUSIONS: Our studies demonstrate that YAP/TAZ are major signaling molecules downstream of LOF AXIN1 mutant HCCs, and targeting YAP/TAZ is an effective treatment against AXIN1 mutant human HCCs.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Camundongos , Animais , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , beta Catenina/genética , Carcinogênese/genética , Mutação , Via de Sinalização Wnt/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Proteína Axina/genética
14.
Microb Pathog ; 187: 106515, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38160987

RESUMO

In this study, a low molecular weight poly-d-mannose (LMWM) was separated from a mixed polysaccharide synthesized previously. Monosaccharide composition, Fourier-Transform infrared spectroscopy (FT-IR), periodate oxidation and smith degradation were determined. After safety evaluation, the inhibition of LMWM on the different biofilm formation stages of Salmonella enterica serovar Typhimurium (S. Typhimurium) was tested in vitro. Furthermore, the effect of LMWM on the adhesion of S. Typhimurium to Caco-2 cells and cell surface hydrophobicity (CSH) were observed. Results indicated that LMWM was a homopolysaccharide without cytotoxicity and hemolysis, containing both α-mannose and ß-mannose. It showed obvious anti-biofilm activity on S. Typhimurium and mainly activated on the initial adhesion and formation stage, even better than the commercial S. cerevisiae mannan (CM). LMWM inhibited the adhesion of S. Typhimurium on Caco-2 cells with the inhibition rate of 61.04 % at 2 mg/ml. Meanwhile, LMWM decreased the hydrophobicity of S. Typhimurium cell surface. In conclusion, the inhibitory effect on S. Typhimurium biofilm was not caused by bacteriostatic or bactericidal activity of LMWM. The specific anti-adhesion and the decrease of bacterial CSH by LMWM may closely relate to anti-biofilm mechanism. This study provides some supports for the application of LMWM as antibiotics alternative on S. Typhimurium in the future.


Assuntos
Manose , Salmonella typhimurium , Humanos , Manose/metabolismo , Manose/farmacologia , Células CACO-2 , Peso Molecular , Saccharomyces cerevisiae , Espectroscopia de Infravermelho com Transformada de Fourier , Biofilmes
15.
Phys Rev Lett ; 132(8): 083601, 2024 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-38457704

RESUMO

Quantum non-Gaussianity, a more potent and highly useful form of nonclassicality, excludes all convex mixtures of Gaussian states and Gaussian parametric processes generating them. Here, for the first time, we conclusively test quantum non-Gaussian coincidences of entangled photon pairs with the Clauser-Horne-Shimony-Holt-Bell factor S=2.328±0.004 from a single quantum dot with a depth up to 0.94±0.02 dB. Such deterministically generated photon pairs fundamentally overcome parametric processes by reducing crucial multiphoton errors. For the quantum non-Gaussian depth of the unheralded (heralded) single-photon state, we achieve the value of 8.08±0.05 dB (19.06±0.29 dB). Our Letter experimentally certifies the exclusive quantum non-Gaussianity properties highly relevant for optical sensing, communication, and computation.

16.
Phys Rev Lett ; 132(16): 160801, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38701444

RESUMO

A solid-state approach for quantum networks is advantageous, as it allows the integration of nanophotonics to enhance the photon emission and the utilization of weakly coupled nuclear spins for long-lived storage. Silicon carbide, specifically point defects within it, shows great promise in this regard due to the easy of availability and well-established nanofabrication techniques. Despite of remarkable progresses made, achieving spin-photon entanglement remains a crucial aspect to be realized. In this Letter, we experimentally generate entanglement between a silicon vacancy defect in silicon carbide and a scattered single photon in the zero-phonon line. The spin state is measured by detecting photons scattered in the phonon sideband. The photonic qubit is encoded in the time-bin degree of freedom and measured using an unbalanced Mach-Zehnder interferometer. Photonic correlations not only reveal the quality of the entanglement but also verify the deterministic nature of the entanglement creation process. By harnessing two pairs of such spin-photon entanglement, it becomes straightforward to entangle remote quantum nodes at long distance.

17.
Inorg Chem ; 63(4): 2060-2071, 2024 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-38232754

RESUMO

The synthesis of two versatile fluorescent metal-organic frameworks (MOFs), [Eu(4-NCP)(1,4-bdc)]n·0.5H2O (1) and [Eu(4-NCP)(4,4'-bpdc)]n·0.75H2O (2) (HNCP = 2-(4-carboxyphenyl)imidazo(4,5-f)-(1,10)phenanthroline, 1,4-H2bdc = benzene-1,4-dicarboxylic acid, 4,4'-H2bpdc = 4,4'-biphenyldicarboxylic acid), was carried out using a hydrothermal method. These MOFs were characterized through various advanced technologies to determine their structural information. The results indicate that both MOFs exhibited 3D network structures with specific topologies. Furthermore, these MOFs demonstrated exceptional thermal stabilities and adsorption capabilities. Additionally, complex 2 was utilized for studying the fluorescence sensing properties of various micronutrients including metal ions, nitro aromatic compounds, and biological small molecules. Notably, complex 2 showed promising potential as a multifunctional sensor for selectively detecting Fe3+, nitrobenzene, and ascorbic acid in aqueous solutions through fluorescence quenching with low limits of detection (LODs ∼ 10-7 M) and high quenching constants (Ksv ∼ 103 M-1). Moreover, the detection mechanism of complex 2 was further investigated by using experimental methods and DFT calculations.

18.
Environ Res ; 251(Pt 1): 118614, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38462084

RESUMO

Organophosphate esters (OPEs) have been widely used as flame retardants and plasticizers in consumer and industrial products. They have been found to have numerous exposure hazards. Recently, several OPEs have been detected in surface waters around the world, which may pose potential ecological risks to freshwater organisms. In this study, the concentration, spatial variation, and ecological risk of 15 OPEs in the Beiyun and Yongding rivers were unprecedentedly investigated by the ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and risk quotient (RQ) method. The result showed that triethyl phosphate (TEP), tri (2-chloroisopropyl) phosphate (TCPP) were the most abundant OPEs with average concentrations of 55.53 ng/L and 42.29 ng/L, respectively. The concentrations of OPEs in the Beiyun River are higher than in the Yongding River, and their levels were higher in densely populated and industrial areas. The risk assessment showed that there was insignificant from OPEs to freshwater organisms in these rivers (RQs <0.1). The risk was higher downstream than upstream, which was related to human-intensive industrial activities downstream in the Yongding River. The ecological risk of OPEs in surface waters worldwide was estimated by joint probability curves (JPCs), and the result showed that there was a moderate risk for tri (2-chloroethyl) phosphate (TCEP), a low risk for trimethyl phosphate (TMP), and insignificant for other OPEs. In addition, the QSAR-ICE-SSD model was used to calculate the hazardous concentration for 5% (HC5). This result validated the feasibility and accuracy of this model in predicting acute data of OPEs and reducing biological experiments on the toxicity of OPEs. These results revealed the ecological risk of OPEs and provided the scientific basis for environmental managers.


Assuntos
Monitoramento Ambiental , Organofosfatos , Rios , Poluentes Químicos da Água , Medição de Risco , Poluentes Químicos da Água/análise , Organofosfatos/análise , Rios/química , Ésteres/análise , China , Espectrometria de Massas em Tandem , Retardadores de Chama/análise , Cidades
19.
BMC Biol ; 21(1): 237, 2023 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-37904147

RESUMO

BACKGROUND: Melanin plays important roles in morphological development, survival, host-pathogen interactions and in the virulence of phytopathogenic fungi. In Verticillum dahliae, increases in melanin are recognized as markers of maturation of microsclerotia which ensures the long-term survival and stress tolerance, while decreases in melanin are correlated with increased hyphal growth in the host. The conserved upstream components of the VdCmr1-regulated pathway controlling melanin production in V. dahliae have been extensively identified, but the direct activators of this pathway are still unclear. RESULTS: We identified two genes encoding conserved C2H2-type zinc finger proteins VdZFP1 and VdZFP2 adjacent to VdPKS9, a gene encoding a negative regulator of both melanin biosynthesis and microsclerotia formation in V. dahliae. Both VdZFP1 and VdZFP2 were induced during microsclerotia development and were involved in melanin deposition. Their localization changed from cytoplasmic to nuclear in response to osmotic pressure. VdZFP1 and VdZFP2 act as modulators of microsclerotia melanization in V. dahliae, as confirmed by melanin biosynthesis inhibition and supplementation with the melanin pathway intermediate scytalone in albino strains. The results indicate that VdZFP1 and VdZFP2 participate in melanin biosynthesis by positively regulating VdCmr1. Based on the results obtained with yeast one- and two-hybrid (Y1H and Y2H) and bimolecular fluorescence complementation (BiFC) systems, we determined the melanin biosynthesis relies on the direct interactions among VdZFP1, VdZFP2 and VdCmr1, and these interactions occur on the cell walls of microsclerotia. Additionally, VdZFP1 and/or VdZFP2 mutants displayed increased sensitivity to stress factors rather than alterations in pathogenicity, reflecting the importance of melanin in stress tolerance of V. dahliae. CONCLUSIONS: Our results revealed that VdZFP1 and VdZFP2 positively regulate VdCmr1 to promote melanin deposition during microsclerotia development, providing novel insight into the regulation of melanin biosynthesis in V. dahliae.


Assuntos
Ascomicetos , Verticillium , Melaninas , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Verticillium/genética , Dedos de Zinco , Doenças das Plantas/microbiologia
20.
Mikrochim Acta ; 191(7): 377, 2024 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-38850342

RESUMO

A novel molecularly imprinted ratiometric fluorescent sensor CQDs@MIP/FITC@SiO2 for the detection of p-nitroaniline (p-NA) was constructed through the mixture of CQDs@MIP and FITC@SiO2 in the ratio of 1:1 (VCQDs@MIP:VFITC@SiO2). The polymers of CQDs@MIP and FITC@SiO2 were prepared by sol-gel method and reversed-phase microemulsion method, respectively. CQDs@MIP was used as the auxiliary response signal and FITC@SiO2 was used as the reference enhancement signal. The signal was measured at excitation/emission wavelengths of 365/438, 512 nm. The sensor showed good linearity in the concentration range 0.14-40.00 µM (R2 = 0.998) with a detection limit of 0.042 µM for p-NA. The color change of "blue-cyan-green" could be observed by the naked eye under 365 nm UV light, thus realizing the visual detection of p-NA. The sensor presented comparable results compared with high-performance liquid chromatography (HPLC) method for the detection of p-NA in hair dye paste and aqueous samples with recoveries of 96.8-103.7% and 95.8-104.4%, respectively. It was demonstrated that the constructed sensor possesses the advantages of simplicity, excellent selectivity, superior sensitivity, and outstanding stability.

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