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1.
Adv Mater ; : e2404232, 2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-38934440

RESUMO

Pairing the positive and negative electrodes with their individual dynamic characteristics at a realistic cell level is essential to the practical optimal design of electrochemical energy storage devices (EESDs). However, the complex relationship between the performance data measured for individual electrodes and the two-electrode cells used in practice often makes an optimal pairing experimentally challenging. Taking advantage of our developed tunable graphene-based electrodes with controllable structure, we successfully unite experiments with machine learning to generate a large pool of capacitance data for graphene-based electrode materials with varied slit pore sizes, thicknesses, and charging rates and numerically pair them into different combinations for two-electrode cells. The results show that the optimal pairing parameters of positive and negative electrodes vary considerably with the operation rate of the cells and are even influenced by the thickness of inactive components. The best-performing individual electrode does not necessarily result in optimal cell-level performance. The machine learning-assisted pairing approach presents much higher efficiency compared with the traditional trial-and-error approach for the optimal design of supercapacitors. The results observed in this work also indicate the call for comprehensive performance data reporting in the electrochemical energy storage field to enable the adoption of artificial intelligence techniques to efficiently translate well-developed high-performance individual electrode materials into real energy storage devices. This article is protected by copyright. All rights reserved.

2.
ACS Appl Mater Interfaces ; 16(24): 31480-31488, 2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38838344

RESUMO

The alkaline hydrogen evolution reaction (HER) is intricately linked to the water dissociation kinetics. The quest for new strategies to accelerate this step is a pivotal aspect of enhancing the HER performance. Herein, we designed and synthesized a heterogeneous nickel phosphide/cobalt phosphide nanowire array grown on nickel foam (Ni2P/CoP/NF) to form a p-n junction structure. The built-in electric field (BEF) in the p-n junction optimizes the binding ability of hydrogen and hydroxyl intermediates, efficiently promoting water dissociation for the alkaline HER. Consequently, Ni2P/CoP/NF exhibits a lower overpotential of 58 and 118 mV at 30 and 100 mA cm-2, respectively, and high stability over 40 h at 300 mA cm-2 for the HER in 1 M KOH. Computational calculations combined with experiment results testify that the BEF presence in the p-n junction of Ni2P/CoP/NF effectively promotes water dissociation, regulates intermediate adsorption/desorption, and boosts electron transport. This study presents a rational design approach for high-performance heterogeneous electrocatalysts.

3.
J Colloid Interface Sci ; 667: 249-258, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38636226

RESUMO

Alloys with bimetallic electron modulation effect are promising catalysts for the electrooxidation of urea. However, the side reaction oxygen evolution reaction (OER) originating from the competitive adsorption of OH- and urea severely limited the urea oxidation reaction (UOR) activity on the alloy catalysts. This work successfully constructs the defect-rich NiCo alloy with lattice strain (PMo-NiCo/NF) by rapid pyrolysis and co-doping. By taking advantage of the compressive strain, the d-band center of NiCo is shifted downward, inhibiting OH- from adsorbing on the NiCo site and avoiding the detrimental OER. Meanwhile, the oxygenophilic P/Mo tailored specific adsorption sites to adsorb OH- preferentially, which further released the NiCo sites to ensure the enriched adsorption of urea, thus improving the UOR efficiency. As a result, PMo-NiCo/NF only requires 1.27 V and -57 mV to drive a current density of ±10 mA cm-2 for UOR and hydrogen evolution reaction (HER), respectively. With the guidance of this work, reactant competing adsorption sites could be tailored for effective electrocatalytic performance.

4.
Int J Biol Macromol ; 266(Pt 2): 131289, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38570002

RESUMO

Intranasal vaccination offers crucial protection against influenza virus pandemics. However, antigens, especially subunit antigens, often fail to induce effective immune responses without the help of immune adjuvants. Our research has demonstrated that a polyelectrolyte complex, composed of curdlan sulfate/O-(2-hydroxyl) propyl-3-trimethyl ammonium chitosan chloride (CS/O-HTCC), effectively triggers both mucosal and systemic immune responses when administrated intranasal. In this study, stable nanoparticles formed by curdlan-O-HTCC conjugate (CO NP) were prepared and characterized. Furthermore, the efficacy of CO NP was evaluated as a mucosal adjuvant in an intranasal influenza H1N1 subunit vaccine. The results revealed that CO NP exhibits uniform and spherical morphology, with a size of 190.53 ± 4.22 nm, and notably, it remains stable in PBS at 4 °C for up to 6 weeks. Biological evaluation demonstrated that CO NP stimulates the activation of antigen-presenting cells (APCs), including macrophages and dendritic cells (DCs), both in vitro and in vivo. Furthermore, intranasal administration of CO NP effectively elicits cellular and humoral immune responses, notably enhancing mucosal immunity. Thus, CO NP emerges as a promising mucosal adjuvant for influenza subunit vaccines.


Assuntos
Adjuvantes Imunológicos , Administração Intranasal , Quitosana , Vírus da Influenza A Subtipo H1N1 , Vacinas contra Influenza , Nanopartículas , Vacinas de Subunidades Antigênicas , beta-Glucanas , Vírus da Influenza A Subtipo H1N1/imunologia , Quitosana/química , Nanopartículas/química , Vacinas contra Influenza/imunologia , Vacinas contra Influenza/química , Vacinas contra Influenza/administração & dosagem , beta-Glucanas/química , beta-Glucanas/farmacologia , beta-Glucanas/administração & dosagem , Animais , Adjuvantes Imunológicos/farmacologia , Adjuvantes Imunológicos/química , Adjuvantes Imunológicos/administração & dosagem , Camundongos , Vacinas de Subunidades Antigênicas/imunologia , Vacinas de Subunidades Antigênicas/administração & dosagem , Imunidade nas Mucosas/efeitos dos fármacos , Camundongos Endogâmicos BALB C , Feminino , Células Dendríticas/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Infecções por Orthomyxoviridae/imunologia
5.
ACS Omega ; 9(9): 10233-10242, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38463306

RESUMO

The red bed region in west central and southern China is affected by hot and humid climate, where sandstone is intensely weathered. The weathered hazardous rocks seriously threaten the road and slope, making it challenging to protect the Danxia red bed. After considering the red sandstone's material composition and the local area's main weathering effects. We noticed that iron ions in red sandstone are susceptible to weathering, which leads to changes in the valence and content of iron ions. This study attempts to establish a new chemical weathering index called the "iron ion relative weathering index" (IRWI) to classify the weathering degree of red sandstone. This paper mainly explores the changes of physical characteristics (mineral composition, physical indicator, microstructure, and pore structure) from the surface to the interior of red sandstone in the actual environment and their correlation with IRWI. The study on the correlation between the physical indicators such as longitudinal wave velocity, resistivity, density, water absorption, and IRWI reveals that they have the same trends and are closely related to the weathering degree. The shallow weathering zone of Chishui red sandstone is divided into strong, medium, and slight weathering zones. Microscopically, the cementation and pore distribution of the red sandstone are consistent with the characteristics of the weathering zone. Therefore, IRWI not only is a reliable chemical quantitative method in indicating the weathering of red sandstone but also takes into account the controlling role of iron in the color development of red beds, which provides a new research idea for the quantitative identification of weathering degree and color mechanism of red sandstone.

6.
J Colloid Interface Sci ; 663: 1019-1027, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38452543

RESUMO

Designing efficient non-precious metal-based catalysts for urea oxidation reaction (UOR) is essential for achieving energy-saving hydrogen production and the treatment of wastewater containing ammonia. In this study, sodium dodecyl sulfate (SDS) is employed as a sacrificial template to synthesize NiCo alloy nanowires (NiCo(SDS)/CC), and the instinct formation mechanism is investigated. It is found that SDS can inhibit the Ostwald ripening during hydrothermal and calcination processes, which could release abundant active cobalt, thereby modulating the electronic structure to promote the catalytic reaction. Moreover, SDS as a sacrificial template can induce the deposition of metal atoms and increase the specific surface area of the catalyst, providing abundant active sites to accelerate the reaction kinetics. As expected, the NiCo(SDS)/CC exhibits good activity for both UOR and hydrogen evolution reactions (HER) and it requires only 1.31 V and -86 mV to obtain a current density of ±10 mA cm-2, respectively. This work provides a new strategy for reducing the agglomeration of transition metals to design high-performance composite catalysts for urea oxidation.

7.
Discov Oncol ; 15(1): 52, 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38416262

RESUMO

BACKGROUND: Gan-song Yin (GSY) is originated from the scripture "Gan-song Pills", a medical work of the Ningxia ethnic minorities, and its treatment of kidney diseases has good results. Its method of treating Renal clear cell carcinoma (KIRC) is still unknown, nevertheless. METHODS: Firstly, utilizing a network pharmacology strategy to screen GSY for active components and targets and looking up KIRC-related targets in GeneCards and GEO databases. Secondly, protein interaction networks were constructed and analyzed for GO and KEGG enrichment. Molecular docking was then performed and clinical and other correlations of the network pharmacology results were analyzed using bioinformatic analysis methods. Finally, we performed in vitro cellular experiments with 786-O cells and ACHN cells to validate the results of network pharmacology and bioinformatic analysis. RESULTS: With the help of network pharmacological analysis, six hub targets were eliminated. Bioinformatics study revealed that the hub targets has clinically significant clinical guiding importance. The results showed that GSY inhibited the proliferation of 786-O cells and ACHN cells, induced cell apoptosis, blocked cell cycle, and reduced cell colony formation ability. qRT-PCR results showed that GSY promoted the expression of ALB and CASP3 genes, and inhibited the expression of EGFR, JUN, MYC and VEGFA genes. Western blot results showed that GSY could promote the expression of ALB and CASP3 protein, and inhibit the expression of EGFR, JUN, MYC and VEGFA protein. CONCLUSIONS: Network pharmacology and bioinformatics analysis showed that GSY could act on multiple targets through a variety of components to achieve the effect of treating KIRC. In this study, we confirmed that GSY inhibits KIRC by regulating the expression of core targets through in vitro cellular experiments, thus providing a reference for subsequent related studies.

8.
Aging (Albany NY) ; 16(4): 4052-4073, 2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38334963

RESUMO

Hepatocellular carcinoma (HCC) is a prevalent liver malignancy with complex etiology and generally poor prognosis. Recently, long non-coding RNAs (lncRNAs), non-protein-coding RNA molecules exceeding 200 nucleotides, have emerged as pivotal players in HCC, influencing its initiation, progression, invasion, and metastasis. These lncRNAs modulate gene expression at epigenetic, transcriptional, and post-transcriptional levels, actively participating in the pathological and physiological processes of HCC. Understanding the intricate relationship between lncRNAs and HCC is important for improving prognosis and reducing mortality. This review summarizes advancements in elucidating the role of lncRNAs in HCC pathogenesis.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , RNA Longo não Codificante , Humanos , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Regulação Neoplásica da Expressão Gênica , Prognóstico
9.
ACS Appl Mater Interfaces ; 15(51): 59989-60001, 2023 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-38085924

RESUMO

Flexible actuators have garnered significant interest in the domains of biomedical devices, human-machine interfaces, and smart wearables. However, the mechanical properties of existing materials are not sufficiently robust, and the expensive and time-consuming pretreatment process and the ambiguous high-degree-of-freedom deformation mechanism make it difficult to meet the demands of industrialized production. Hence, drawing inspiration from the adaptable movement of living organisms in the natural world, this research created and engineered a fully textile-based humidity-sensitive flexible actuator (TbHs-FA) using high-cost-effective viscose/PET fibers as raw materials. The breakthrough development in actuation performance is covered, including substantial contraction force (92.53 cN), high actuation curvature (16.78 cm-1), and fast response (264 cN s-1 and 46.61 cm-1 s-1). Additionally, the programmable stiffness system and weave structure give TbHs-FAs low hysteresis and fatigue resistance, narrowing the gap between the conceptual laboratory-scale design of existing fully textile-based humidity-sensitive flexible actuators and actual textiles. The high-degree-of-freedom and large bending deformation mechanisms are elucidated for the first time by combining microscopic mechanical structure simulation and macroscopic energy conversion analysis. The novel humidity-sensitive flexible actuator possesses strong mechanical qualities, making it suitable for applications such as flexible robots, medicinal devices, and smart wearables.


Assuntos
Hipertelorismo , Hipospadia , Dispositivos Eletrônicos Vestíveis , Humanos , Masculino , Simulação por Computador , Umidade
10.
Microsc Microanal ; 29(6): 2174-2183, 2023 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-38066680

RESUMO

N6-methyladenosine (m6A), the most prevalent modification in eukaryotic messenger RNA (mRNA), plays a key role in various developmental processes in mammals. Three proteins that affect RNA m6A modification have been identified: methyltransferases, demethylases, and m6A-binding proteins, known as "writer," "eraser," and "reader" proteins, respectively. However, changes in the m6A modification when early porcine embryos are exposed to stress remain unclear. In this study, we exposed porcine oocytes to a high temperature (HT, 41°C) for 10 h, after which the mature oocytes were parthenogenetically activated and cultured for 7 days to the blastocyst stage. HT significantly decreased the rates of the first polar body extrusion and blastocyst formation. Further detection of m6A modification found that HT can lead to increased expression levels of "reader," YTHDF2, and "writer," METTL3, and decreased expression levels of "eraser," FTO, resulting in an increased level of m6A modification in the embryos. Additionally, heat shock protein 70 (HSP70) is upregulated under HT conditions. Our study demonstrated that HT exposure alters m6A modification levels, which further affects early porcine embryonic development.


Assuntos
Desenvolvimento Embrionário , Epigênese Genética , Animais , Suínos , Temperatura , Mamíferos
11.
Front Cell Dev Biol ; 11: 1238546, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37965572

RESUMO

Y-box binding protein 1 (YBX1) plays important roles in RNA stabilization, translation, transcriptional regulation, and mitophagy. However, its effects on porcine preimplantation embryos remain unclear. In this study, we knocked down YBX1 in the one-cell (1C) stage embryo via small interfering RNA microinjection to determine its function in porcine embryo development. The mRNA level of YBX1 was found to be highly expressed at the four-cell (4C) stage in porcine embryos compared with one-cell (1C) and two-cell (2C) stages. The number of blastocysts was reduced following YBX1 knockdown. Notably, YBX1 knockdown decreased the phosphatase and tensin homolog-induced kinase 1 (PINK1) and parkin RBR E3 ubiquitin protein ligase (PRKN) mRNA levels. YBX1 knockdown also decreased PINK1, active mitochondria, and sirtuin 1 levels, indicating reduced mitophagy and mitochondrial biogenesis. Furthermore, YBX1 knockdown increased the levels of glucose-regulated protein 78 (GRP78) and calnexin, leading to endoplasmic reticulum (ER) stress. Additionally, YBX1 knockdown increased autophagy and apoptosis. In conclusion, knockdown of YBX1 decreases mitochondrial function, while increasing ER stress and autophagy during embryonic development.

12.
Aging Dis ; 2023 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-37962467

RESUMO

Autophagy is a biological phenomenon whereby components of cells can self-degrade using autophagosomes. During this process, cells can clear dysfunctional organelles or unwanted elements. Autophagy can recycle unnecessary biomolecules into new components or sometimes, even destroy the cells themselves. This cellular process was first observed in 1962 by Keith R. Porter et al. Since then, autophagy has been studied for over 60 years, and much has been learned on the topic. Nevertheless, the process is still not fully understood. It has been proven, for example, that autophagy can be a positive force for maintaining good health by removing older or damaged cells. By contrast, autophagy is also involved in the onset and progression of various conditions caused by pathogenic infections. These diseases generally involve several important organs in the human body, including the liver, kidney, heart, and central nervous system. The regulation of the defects of autophagy defects may potentially be used to treat some diseases. This review comprehensively discusses recent research frontiers and topics of interest regarding autophagy-related diseases.

13.
Nanomaterials (Basel) ; 13(20)2023 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-37887928

RESUMO

Graphene oxide (GO) two-dimensional (2D) membranes with unique layer structures and tunable layer spacing have special advantages and great potential in the field of water treatment. However, GO membranes face the issues of weak anti-swelling ability as well as poor permeability. We prepared GO/Ti3C2TX 2D composite membranes with 2D/2D structures by intercalating Ti3C2TX nanosheets with slightly smaller sizes into GO membranes. Ti3C2TX intercalation can effectively expand the layer spacing of GO, thereby substantially enhancing the flux of the composite membrane (2.82 to 6.35 L·m-2·h-1). Moreover, the GO/Ti3C2TX composite membrane exhibited a good Mg2+/Li+ separation capability. For the simulated brine, the separation factor of M2 was 3.81, and the salt solution flux was as high as 5.26 L·m-2·h-1. Meanwhile, the incorporation of Ti3C2TX nanosheets significantly improved the stability of GO/Ti3C2TX membranes in different pH environments. This study provides a unique insight into the preparation of highly permeable and ion-selective GO membranes.

14.
Opt Express ; 31(20): 32554-32564, 2023 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-37859056

RESUMO

Tracking and imaging for high-speed moving objects have a wide range of application prospects in many fields, such as transportation and security monitoring. In this paper, the chrome plated masks are designed to carry geometric moment and random binary encoding patterns, combined with single pixel detectors, to achieve real-time tracking and imaging of fast-moving object. By using the geometric moment principle to obtain the motion trajectory of the object, coding sub-patterns and corresponding detection signals are extracted at different positions to reconstruct the image of the object. Multiple optical paths are established to avoid the side effects of motion error, and a dedicated calibration approach is proposed to improve the accuracy of tracking. The feasibility of the method is demonstrated by simulations and experiments. The proposed scheme, which modulates light with static mask instead of spatial light modulator (SLM), improves the speed and spectral range meanwhile reduces the system cost.

15.
Microbiol Spectr ; 11(6): e0205923, 2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-37882566

RESUMO

IMPORTANCE: Since the escape immunity of influenza A viruses (IAVs) is mainly caused by the continuous antigenic variations in HA, the identification of key antigenic epitopes is crucial for better understanding of the escape immunity and vaccine development for IAVs. The antigenic sites of several HA subtypes, including H1, H3, H5, and H9, have been well characterized, whereas those of H6 subtype are poorly understood. Here, we mapped nine key residues of antigenic epitopes in H6 through escape mutants using a panel of MAbs. Moreover, MAbs 4C2 and 6E3, targeting 140 and 89 residues, respectively, could protect mice against lethal challenge of MA E-Teal/417. These key residues of antigenic epitopes identified here provide the molecular targets for further elucidating the antigenic evolution of H6 and better preparing the vaccine against H6 IAV.


Assuntos
Vírus da Influenza A , Influenza Humana , Animais , Camundongos , Humanos , Vírus da Influenza A/genética , Hemaglutininas , Epitopos de Linfócito B/genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Anticorpos Antivirais , Influenza Humana/prevenção & controle
16.
Nucleic Acids Res ; 51(18): 9552-9566, 2023 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-37697433

RESUMO

Intrinsic DNA properties including bending play a crucial role in diverse biological systems. A recent advance in a high-throughput technology called loop-seq makes it possible to determine the bendability of hundred thousand 50-bp DNA duplexes in one experiment. However, it's still challenging to assess base-resolution sequence bendability in large genomes such as human, which requires thousands of such experiments. Here, we introduce 'BendNet'-a deep neural network to predict the intrinsic DNA bending at base-resolution by using loop-seq results in yeast as training data. BendNet can predict the DNA bendability of any given sequence from different species with high accuracy. To explore the utility of BendNet, we applied it to the human genome and observed DNA bendability is associated with chromatin features and disease risk regions involving transcription/enhancer regulation, DNA replication, transcription factor binding and extrachromosomal circular DNA generation. These findings expand our understanding on DNA mechanics and its association with transcription regulation in mammals. Lastly, we built a comprehensive resource of genomic DNA bendability profiles for 307 species by applying BendNet, and provided an online tool to assess the bendability of user-specified DNA sequences (http://www.dnabendnet.com/).

17.
J Infect Dis ; 2023 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-37738556

RESUMO

Coxsackievirus (CV) A6 is currently considered as a predominant pathogen of hand, foot, and mouth disease (HFMD), and is occasionally linked to myocardial injury. We first established a mouse model of CVA6-induced myocardial injury. Next, we analyzed the immune cell phenotypes CVA6-infected mice hearts by FACS, and found that CVA6 led to massive neutrophils infiltration, suggesting their potential link with the occurrence of myocardial injury. We further used either αGr-1 or αLy6G antibody to deplete neutrophils, and found that neutrophil-depleted animals showed decreased cardiac enzymes, lower degree pathology in hearts, and reduced inflammatory cytokine production compared to isotype controls. Finally, we confirmed the involvement of neutrophils in myocardial injury of clinical patients with severe HFMD. Overall, our study suggests that excessive neutrophils contribute to myocardial injury caused by CVA6 infection, which provides new insight into myocardial injury during the development of HFMD severity and the outcome of immune cell-mediated therapies.

18.
Int J Mol Sci ; 24(15)2023 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-37569497

RESUMO

Zinc finger and SCAN domain-containing 4 (ZSCAN4), a DNA-binding protein, maintains telomere length and plays a key role in critical aspects of mouse embryonic stem cells, including maintaining genomic stability and defying cellular senescence. However, the effect of ZSCAN4 in porcine parthenogenetic embryos remains unclear. To investigate the function of ZSCAN4 and the underlying mechanism in porcine embryo development, ZSCAN4 was knocked down via dsRNA injection in the one-cell stage. ZSCAN4 was highly expressed in the four- and five- to eight-cell stages in porcine embryos. The percentage of four-cell stage embryos, five- to eight-cell stage embryos, and blastocysts was lower in the ZSCAN4 knockdown group than in the control group. Notably, depletion of ZSCAN4 induced the protein expression of DNMT1 and 5-Methylcytosine (5mC, a methylated form of the DNA base cytosine) in the four-cell stage. The H3K27ac level and ZGA genes expression decreased following ZSCAN4 knockdown. Furthermore, ZSCAN4 knockdown led to DNA damage and shortened telomere compared with the control. Additionally, DNMT1-dsRNA was injected to reduce DNA hypermethylation in ZSCAN4 knockdown embryos. DNMT1 knockdown rescued telomere shortening and developmental defects caused by ZSCAN4 knockdown. In conclusion, ZSCAN4 is involved in the regulation of transcriptional activity and is essential for maintaining telomere length by regulating DNMT1 expression in porcine ZGA.


Assuntos
Telômero , Fatores de Transcrição , Animais , Camundongos , Suínos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Telômero/genética , Telômero/metabolismo , Encurtamento do Telômero , Proteínas de Ligação a DNA/metabolismo , Zigoto/metabolismo , Desenvolvimento Embrionário/genética , Regulação da Expressão Gênica no Desenvolvimento
19.
ACS Chem Biol ; 18(7): 1632-1641, 2023 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-37427444

RESUMO

Glycosaminoglycan synthases have immense potential in applications involving synthesis of oligosaccharides, using enzymatic approaches and construction of cell factories that produce polysaccharides as critical metabolic components. However, the use of high-throughput activity assays to screen for the evolution of these enzymes can be challenging because there are no significant changes in fluorescence or absorbance associated with glycosidic bond formation. Here, using incorporation of azido-labeled N-acetylhexosamine analogs into bacterial capsule polysaccharides via bacterial metabolism and bioorthogonal chemistry, fluorophores were specifically introduced onto cell surfaces. Furthermore, correlations between detectable fluorescence signals and the polysaccharide-synthesizing capacity of individual bacteria were established. Among 10 candidate genes, 6 members of the chondroitin synthase family were quickly identified in a recombinant Bacillus subtilis host strain. Additionally, directed evolution of heparosan synthase was successfully performed using fluorescence-activated cell sorting of recombinant Escherichia coli O10:K5(L):H4, yielding several mutants with increased activity. Cell-based approaches that selectively detect the presence or absence of synthases within an individual colony of bacterial cells, as well as their level of activity, have broad potential in the exploration and engineering of glycosaminoglycan synthases. These approaches also support the creation of novel strategies for high-throughput screening of enzyme activity based on cell systems.


Assuntos
Glicosaminoglicanos , Engenharia Metabólica , Ensaios de Triagem em Larga Escala , Escherichia coli , Bactérias/genética , Polissacarídeos Bacterianos
20.
Biochem Biophys Res Commun ; 675: 113-121, 2023 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-37467664

RESUMO

The recent outbreak of Corona Virus Disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been a severe threat to the global public health and economy, however, effective drugs to treat COVID-19 are still lacking. Here, we employ a deep learning-based drug repositioning strategy to systematically screen potential anti-SARS-CoV-2 drug candidates that target the cell entry mechanism of SARS-CoV-2 virus from 2635 FDA-approved drugs and 1062 active ingredients from Traditional Chinese Medicine herbs. In silico molecular docking analysis validates the interactions between the top compounds and host receptors or viral spike proteins. Using a SARS-CoV-2 pseudovirus system, we further identify several drug candidates including Fostamatinib, Linagliptin, Lysergol and Sophoridine that can effectively block the cell entry of SARS-CoV-2 variants into human lung cells even at a nanomolar scale. These efforts not only illuminate the feasibility of applying deep learning-based drug repositioning for antiviral agents by targeting a specified mechanism, but also provide a valuable resource of promising drug candidates or lead compounds to treat COVID-19.


Assuntos
COVID-19 , Aprendizado Profundo , Humanos , SARS-CoV-2 , Reposicionamento de Medicamentos , Simulação de Acoplamento Molecular , Internalização do Vírus , Antivirais/farmacologia
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