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1.
Angew Chem Int Ed Engl ; 62(39): e202308306, 2023 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-37461155

RESUMO

The shortage of narrow band gap polymer acceptors with high electron mobility is the major bottleneck for developing efficient all-polymer solar cells (all-PSCs). Herein, we synthesize a distannylated electron-deficient biselenophene imide monomer (BSeI-Tin) with high purity/reactivity, affording an excellent chance to access acceptor-acceptor (A-A) type polymer acceptors. Copolymerizing BSeI-Tin with dibrominated monomer Y5-Br, the resulting A-A polymer PY5-BSeI shows a higher molecular weight, narrower band gap, deeper-lying frontier molecular orbital levels and larger electron mobility than the donor-acceptor type counterpart PY5-BSe. Consequently, the PY5-BSeI-based all-PSCs deliver a remarkable efficiency of 17.77 % with a high short-circuit current of 24.93 mA cm-2 and fill factor of 75.83 %. This efficiency is much higher than that (10.70 %) of the PY5-BSe-based devices. Our study demonstrates that BSeI is a promising building block for constructing high-performance polymer acceptors and stannylation of electron-deficient building blocks offers an excellent approach to developing A-A type polymers for all-PSCs and even beyond.

2.
Genomics ; 112(4): 2875-2885, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32247005

RESUMO

Circular RNAs (circRNAs) are evolutionarily conserved and tissue-specific types of non-coding RNA and can serve as potential diagnostic biomarkers for disease. However, the clinical significance and levels of expression of circRNAs for whole blood samples of prematurely born infants afflicted by diseases such as periventricular white matter damage (PWMD) are largely unknown. Therefore, we sought to identify measures of expression of circRNAs in whole blood samples obtained from prematurely born infants afflicted by PWMD and comparatively in samples from prematurely born infants without PWMD. We found the expression levels of circRNAs which from premature with PWMD has changed. Further analysis suggests that these circRNAs have important roles in PWMD. This study can improve the understanding for the potential of the circRNAs to serve as biomarkers in PWMD. Moreover, these circRNAs may provide evidence for improving diagnosis and treatment for infants afflicted by PWMD, and merits continued research.


Assuntos
Doenças do Prematuro/genética , Leucoencefalopatias/genética , RNA Circular/sangue , Biomarcadores/sangue , Encéfalo/diagnóstico por imagem , Feminino , Regulação da Expressão Gênica , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Doenças do Prematuro/sangue , Doenças do Prematuro/diagnóstico , Doenças do Prematuro/diagnóstico por imagem , Leucoencefalopatias/sangue , Leucoencefalopatias/diagnóstico , Leucoencefalopatias/diagnóstico por imagem , Imageamento por Ressonância Magnética , Masculino , MicroRNAs/metabolismo , RNA Circular/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa
3.
Angew Chem Int Ed Engl ; 60(45): 24198-24205, 2021 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-34467624

RESUMO

The development of n-type organic electrochemical transistors (OECTs) lags far behind their p-type counterparts. In order to address this dilemma, we report here two new fused bithiophene imide dimer (f-BTI2)-based n-type polymers with a branched methyl end-capped glycol side chain, which exhibit good solubility, low-lying LUMO energy levels, favorable polymer chain orientation, and efficient ion transport property, thus yielding a remarkable OECT electron mobility (µe ) of up to ≈10-2  cm2 V-1 s-1 and volumetric capacitance (C*) as high as 443 F cm-3 , simultaneously. As a result, the f-BTI2TEG-FT-based OECTs deliver a record-high maximum geometry-normalized transconductance of 4.60 S cm-1 and a maximum µC* product of 15.2 F cm-1 V-1 s-1 . The µC* figure of merit is more than one order of magnitude higher than that of the state-of-the-art n-type OECTs. The emergence of f-BTI2TEG-FT brings a new paradigm for developing high-performance n-type polymers for low-power OECT applications.

4.
J Cell Mol Med ; 23(7): 4808-4818, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31094081

RESUMO

Coagulase (Coa) activity is essential for the virulence of Staphylococcus aureus (S aureus), one of the most important pathogenic bacteria leading to catheter-related bloodstream infections (CRBSI). We have demonstrated that the mutation of coagulase improved outcomes in disease models of S aureus CRBSI, suggesting that targeting Coa may represent a novel antiinfective strategy for CRBSI. Here, we found that quercetin, a natural compound that does not affect S aureus viability, could inhibit Coa activity. Chemical biological analysis revealed that the direct engagement of quercetin with the active site (residues Tyr187, Leu221 and His228) of Coa inhibited its activity. Furthermore, treatment with quercetin reduced the retention of bacteria on catheter surfaces, decreased the bacterial load in the kidneys and alleviated kidney abscesses in vivo. These data suggest that antiinfective therapy targeting Coa with quercetin may represent a novel strategy and provide a new leading compound with which to combat bacterial infections.


Assuntos
Infecções Relacionadas a Cateter/tratamento farmacológico , Infecções Relacionadas a Cateter/microbiologia , Coagulase/antagonistas & inibidores , Substâncias Protetoras/uso terapêutico , Quercetina/uso terapêutico , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/enzimologia , Animais , Aderência Bacteriana/efeitos dos fármacos , Sítios de Ligação , Materiais Biocompatíveis/farmacologia , Coagulase/genética , Coagulase/metabolismo , Estabilidade Enzimática/efeitos dos fármacos , Feminino , Simulação de Dinâmica Molecular , Mutação/genética , Substâncias Protetoras/farmacologia , Quercetina/química , Quercetina/farmacologia , Coelhos , Ratos Wistar , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Staphylococcus aureus/ultraestrutura , Temperatura , Termodinâmica
5.
Appl Microbiol Biotechnol ; 101(17): 6671-6681, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28710559

RESUMO

Staphylococcus aureus (S. aureus) biofilms are clinically serious and play a critical role in the persistence of chronic infections due to their ability to resist antibiotics. The inhibition of biofilm formation is viewed as a new strategy for the prevention of S. aureus infections. Here, we demonstrated that minimum inhibitory concentrations (MICs) of aloe-emodin exhibited no bactericidal activity against S. aureus but affected S. aureus biofilm development in a dose-dependent manner. Further studies indicated that aloe-emodin specifically inhibits the initial adhesion and proliferation stages of S. aureus biofilm development. Scanning electron microscopy (SEM) indicated that the S. aureus ATCC29213 biofilm extracellular matrix is mainly composed of protein. Laser scanning confocal microscope assays revealed that aloe-emodin treatment primarily inhibited extracellular protein production. Moreover, the Congo red assay showed that aloe-emodin also reduced the accumulation of polysaccharide intercellular adhesin (PIA) on the cell surface. These findings will provide new insights into the mode of action of aloe-emodin in the treatment of infections by S. aureus biofilms.


Assuntos
Antraquinonas/farmacologia , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Staphylococcus aureus/efeitos dos fármacos , Aderência Bacteriana/efeitos dos fármacos , Proteínas de Bactérias/metabolismo , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Polissacarídeos Bacterianos/antagonistas & inibidores , Staphylococcus aureus/fisiologia , Staphylococcus aureus/ultraestrutura
6.
Int J Food Microbiol ; 384: 109972, 2023 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-36279642

RESUMO

Plant-derived substances as antifungal agents have received considerable attention in recent years to reduce the use of chemical fungicides in food preservatives. In this study, honokiol, a type of phenolic compound in Magnolia officinalis, was found to inhibit spore germination and mycelia growth of Aspergillus flavus at 100 µg/mL. In addition, a pathogenicity assay showed that honokiol had potent antifungal activity against A. flavus in corn flour by suppressing conidia production. Fluorescence staining, transmission electron microscopy and biochemical assays were performed to explore its possible inhibition mechanisms against A. flavus. The results showed that the destructive effect of honokiol on A. flavus appeared to be related to increased plasma membrane permeability, the inhibition of ATPase activity, mitochondrial dysfunction and the accumulation of reactive oxygen species. Furthermore, a transcriptomic analysis showed that honokiol treatment resulted in 1578 different expressed genes. Gen Ontology and Kyoto Encyclopedia of Genes and Genomes analysis revealed that some genes of A. flavus related to spore development, integrity of the cell wall and membrane, oxidative stress and energy metabolism were significantly downregulated. In addition, RNA-seq results were validated by quantitative real-time polymerase chain reactions. Our finding enhanced the understanding of the antifungal activity of honokiol and underlying mechanisms of action at the molecular level, supporting honokiol as a potential agent in preventing contamination by A. flavus.


Assuntos
Aspergillus flavus , Lignanas , Antifúngicos/metabolismo , Transcriptoma , Lignanas/farmacologia , Lignanas/metabolismo
7.
Int J Food Microbiol ; 402: 110277, 2023 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-37331114

RESUMO

This study evaluated the synergistic antifungal effects of vapor-phase natural agents against Aspergillus flavus with an aim to prevent fungal contamination in agricultural products. Screening different combinations of natural antifungal vapor agents using the checkerboard assay revealed that the cinnamaldehyde and nonanal (SCAN) blend could exert the strongest synergistic antifungal activities against A. flavus, with a minimum inhibitory concentration (MIC) of 0.03 µL/mL, which caused a 76 % decrease in fungal population compared to when each agent was used separately. Subsequent gas chromatography-mass spectrometry (GC/MS) analysis demonstrated that the cinnamaldehyde/nonanal combination was stable and no effects on their individual molecular structures. SCAN at 2 × MIC completely inhibited the fungal conidia production and mycelial growth. The calcofluor white (CFW) and dichloro-dihydro-fluorescein diacetate (DCFH-DA) staining assays showed that SCAN treatment could accelerate the destruction of cell wall integrity and accumulation of reactive oxygen species (ROS) in A. flavus. Moreover, pathogenicity assay indicated that in contrast to separate treatment with cinnamaldehyde or nonanal, SCAN could cause a decrease in the production of A. flavus asexual spores and AFB1 on peanuts, which verified its potential synergistic activity against fungal propagation. In addition, SCAN effectively preserves the organoleptic and nutritional properties of stored peanuts. Overall, our findings strongly indicated that the cinnamaldehyde/nonanal combination is a potentially significant antifungal agent against A. flavus contamination during the postharvest storage of peanuts.


Assuntos
Antifúngicos , Aspergillus flavus , Antifúngicos/farmacologia , Aldeídos/farmacologia
8.
Int J Nanomedicine ; 18: 6119-6136, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37915747

RESUMO

Purpose: Magnetic resonance imaging (MRI) has been a valuable and widely used examination technique in clinical diagnosis and prognostic efficacy evaluation. The introduction of MRI contrast agent (CA) improves its sensitivity obviously, particularly with the development of nano-CA, which presents higher contrast enhancement ability. However, systematical evaluation of their toxicity is still limited, hampering their further translation in clinics. Methods: In this paper, to systematically evaluate the toxicity of nano-CA, Gd-doped mesoporous carbon nanoparticles (Gd-MCNs) prepared by a one-step hard template method were introduced as a model and clinically used MRI CA, Magnevist (Gd-DTPA) as control. Their in vitro blood compatibility, cellular toxicity, DNA damage, oxidative stress, inflammation response as well as in vivo toxicity and MR imaging behaviors were studied and compared. Results: The experimental results showed that compared with Gd-DTPA, Gd-MCNs displayed negligible influence on the red blood cell shape, aggregation, BSA structure, macrophage morphology and mitochondrial function. Meanwhile, limited ROS and inflammatory cytokine production also illustrated the cellular compatibility of Gd-MCNs. For in vivo toxicity evaluation, Gd-MCNs presented acceptable in vivo biosafety even under 12 times injection for 12 weeks. More importantly, at the same concentration of Gd, Gd-MCNs displayed better contrast enhancement of tumor than Gd-DTPA, mainly coming from its high MRI relaxation rate which is nearly 9 times that of Gd-DTPA. Conclusion: In this paper, we focus on the toxicity evaluation of MRI nano-CA, Gd-MCNs from different angles. With Gd-DTPA as control, Gd-MCNs appeared to be highly biocompatible and safe nanoparticles that possessed promising potentials for the use of MRI nano-CA. In the future, more research on the long-term genotoxicity and the fate of nanoparticles after being swallowed should be performed.


Assuntos
Gadolínio DTPA , Nanopartículas , Camundongos , Animais , Gadolínio DTPA/química , Meios de Contraste/toxicidade , Meios de Contraste/química , Nanopartículas/toxicidade , Nanopartículas/química , Imageamento por Ressonância Magnética/métodos , Carbono
9.
Artigo em Inglês | MEDLINE | ID: mdl-36753061

RESUMO

n-Doped small molecular organic thermoelectric materials (OTMs) hold advantages of high Seebeck coefficient and better performance reproducibility over their polymeric analogues; however, high-performance n-type small molecular OTMs are severely lacking. We report here a class of small molecular OTMs based on terminal cyanation of a bithiophene imide-based ladder-type heteroarene BTI2. It was found that the cyanation could effectively lower the lowest unoccupied molecular orbital (LUMO) level from -2.90 eV (BTI2) to -4.14 eV (BTI2-4CN) and thus lead to significantly improved n-doping efficiency. Additionally, terminal cyano-functionalization can maintain the close packing and efficient intermolecular charge transfer between these cyanated molecules, thus yielding high electron mobilities of up to 0.40 cm2 V-1 s-1. Benefiting from its low LUMO-enabled efficient n-doping and high electron mobility, an encouraging n-type electrical conductivity of 0.43 S cm-1 and power factor (PF) of 6.34 µW m-1 K-2 were achieved for tetracyanated BTI2-4CN, significantly outperforming those of its noncynated BTI2 (<10-7 S cm-1, PF undetectable) and dicyanated BTI2-2CN (0.24 S cm-1, 1.78 µW m-1 K-2). These results suggest the great potential of the terminal cyanation strategy of ladder-type heteroarenes for developing high-performance small molecular OTMs.

10.
PLoS One ; 17(3): e0263553, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35358205

RESUMO

During the seed aging process, reactive oxygen species (ROS) can induce the carbonylation of proteins, which changes their functional properties and affects seed vigor. However, the impact and regulatory mechanisms of protein carbonylation on wheat seed vigor are still unclear. In this study, we investigated the changes in wheat seed vigor, carbonyl protein content, ROS content and embryo cell structure during an artificial aging process, and we analyzed the correlation between protein carbonylation and seed vigor. During the artificial wheat-seed aging process, the activity levels of antioxidant enzymes and the contents of non-enzyme antioxidants decreased, leading to the accumulation of ROS and an increase in the carbonyl protein content, which ultimately led to a decrease in seed vigor, and there was a significant negative correlation between seed vigor and carbonyl protein content. Moreover, transmission electron microscopy showed that the contents of protein bodies in the embryo cells decreased remarkably. We postulate that during the wheat seed aging process, an imbalance in ROS production and elimination in embryo cells leads to the carbonylation of proteins, which plays a negative role in wheat seed vigor.


Assuntos
Sementes , Triticum , Antioxidantes/metabolismo , Germinação , Carbonilação Proteica , Espécies Reativas de Oxigênio/metabolismo , Sementes/metabolismo , Triticum/metabolismo
11.
J Food Biochem ; 46(12): e14495, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36322387

RESUMO

Lysine acetylation is a common post-translational modification of proteins within all organisms. However, quantitative acetylome characterization in wheat seed during aging in storage has not been reported. This study reports the first large-scale acetylome analysis of wheat seeds after artificial aging treatment, using the quantitative proteomic approach. In total, 11,002 acetylation sites, corresponding to 4262 acetylated proteins were identified, of which 1207 acetylated sites, representing 783 acetylated proteins, were significantly more or less acetylated after artificial aging. Functional analysis demonstrated that the majority of the acetylated proteins are closely involved with cellular and metabolic functions. In particular, key enzymes in the oxidative stress response and energy metabolism were significantly differentially acetylated and appear to be heavily involved in wheat seed aging. The acetylome analysis was verified by quantitative real-time PCR and enzyme activity determination. Lysine-acetylation results in a weaker oxidative stress response and lower energy production efficiency, resulting in the apoptosis of wheat seed cells, insufficient energy supply at the germination stage, and consequently, marked loss of seed vigor. PRACTICAL APPLICATIONS: It is known that the loss of protein function is an important reason for the decrease of seed vigor. Therefore, the change of protein function in the process of wheat seed aging was studied by proteome and lysine acetylome analysis technology. The results showed that the oxidation-reduction imbalance and the decrease of energy production efficiency of seeds were the important reasons for the decrease of their vigor. This will provide a new idea for green and safe storage of grain.


Assuntos
Lisina , Proteoma , Lisina/metabolismo , Proteoma/análise , Triticum/genética , Triticum/metabolismo , Proteômica/métodos , Sementes/química , Estresse Oxidativo , Oxirredução
12.
Ann Palliat Med ; 10(12): 12244-12250, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35016476

RESUMO

BACKGROUND: The purpose of this study was to evaluate the effects of monovalent and divalent cations on the stability of a fat emulsion (Lipovenoes MCT) in total nutrient admixtures (TNAs) by testing the percentage of fat residing in globules >5 µm (PFAT5) values. METHODS: TNAs with different combinations of glucose (5% and 10%), amino acids (3.35 and 4.5 g/100 mL), Na+/K+ (100/39 mmol/L), Mg2+ (3.4 and 2.7 mmol/L), and fat emulsion (2.4%) were tested in triplicate at room temperature. The pH, mean droplet size (MDS), and PFAT5 were assessed at 0, 6, 12, 24, 36, and 48 h. RESULTS: In all seven groups, the TNA globule distribution was uniform, the pH value fluctuated in the range of 5.93-6.06, and the MDS met the limit of the United States Pharmacopeia (USP) within 48 h. The PFAT5 value of the control group 0 without electrolytes was the lowest; group 1 added monovalent ions of 139 mmol/L was significantly higher (P<0.05) but without exceed the USP limit after 48 h. Groups 2 and 3 added Mg2+ 3.4 and 2.7 mmol/L respectively, based on group 1. Group 4 increased the amino acid concentration from 3.35% to 4.5% based on group 2, and group 5 reduced the glucose concentration from 10% to 5% based on group 4. Group 6 removed monovalent ions and retained only Mg2+ based on group 5. The PFAT5 values of group 2, 3, 4, and 5 exceeded the limit after 6 h and group 6 after 12 h. There was no statistical difference between group 2 and 4 (P>0.05) or between group 4 and 5 (P>0.05). CONCLUSIONS: When the concentration of glucose is 10-25% and the amino acid is 2.5-4.5%, The addition of monovalent ions affects the stability of fat emulsion in TNAs, however when the concentrations of Na+ ≤100 mmol/L and K+ ≤39 mmol/L, the PFAT5 value will not exceed the USP limit within 24 h. Mg2+ has a significant effect, the PFAT5 value will exceed the USP limit after 6 h when the concentration ≥2.7 mmol/L, which may cause potential safety hazards.


Assuntos
Emulsões Gordurosas Intravenosas , Nutrientes , Estabilidade de Medicamentos , Glucose , Humanos , Tamanho da Partícula
13.
Front Genet ; 12: 641526, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33995480

RESUMO

Long non-coding RNA (LncRNA) has high expression in the brain. Animal studies have shown that lncRNA plays an important role in brain functions and mediates the development of many neurological diseases. However, data on the expression of lncRNAs and the clinical significance in prematurely born infants with diseases such as periventricular white matter damage (PWMD) remains scant. Here, we compared the expression of the lncRNAs in whole blood samples obtained from prematurely born infants with PWMD with samples from prematurely born infants without PWMD. Our data demonstrated differential expression of the lncRNAs between the two groups. Further, we showed that the lncRNAs play important roles in the development of PWMD. Our findings give insights into the functions of the lncRNAs in PWMD and provide evidence for the improvement of diagnostic and treatment strategies in infants with PWMD.

14.
Adv Mater ; 33(37): e2102635, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34338383

RESUMO

Narrow-bandgap n-type polymers with high electron mobility are urgently demanded for the development of all-polymer solar cells (all-PSCs). Here, two regioregular narrow-bandgap polymer acceptors, L15 and MBTI, with two electron-deficient segments are synthesized by copolymerizing two dibrominated fused-ring electron acceptors (FREA) with distannylated aromatic imide, respectively. Taking full advantage of the FREA and the imide, both polymer acceptors show narrow bandgap and high electron mobility. Benefiting from the more extended absorption, better backbone ordering, and higher electron mobility than those of its regiorandom analog, the L15-based all-PSC yields a high power conversion efficiency (PCE) of 15.2% when blended with the polymer donor PM6. More importantly, MBTI incorporating a benzothiophene-core FREA segment shows relatively higher frontier molecular orbital levels than L15, forming a cascade-like energy level alignment with L15 and PM6. Based on this, ternary all-PSCs are designed where MBTI is introduced as a guest into the PM6:L15 host system. Thanks to further optimal blend morphology and more balanced charge transport, the PCE is improved up to 16.2%, which is among the highest values for all-PSCs. The results demonstrate that combining an FREA and an aromatic imide to construct regioregular narrow-bandgap polymer acceptors provides an effective approach to fabricate highly efficient all-PSCs.

15.
Carbohydr Polym ; 203: 378-385, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30318226

RESUMO

Although chemotherapy has been widely used in the treatment of many kinds of cancer, drug resistance and side effects are the main obstacles in the cancer chemotherapy that result in an inferior therapeutic outcome. For the design of drug delivery system, extracellular stability and intracellular effective release are also a pair of contradictions. In this research, gold nanorods (AuNRs) loaded hyaluronic acid (HA) nanogels with reduction sensitivity were prepared for the efficient intracellular delivery of doxorubicin (DOX). The aforementioned HA-CysNG@AuNR nanogels with cystamine (Cys) as crosslinker could remain stable in the physiological condition and release DOX rapidly in the mimic intracellular glutathione (GSH) condition. Meanwhile, the cellular uptake efficiency by the human breast carcinoma (MCF-7) cells was enhanced because of the highly expressed HA receptor (CD44) on the cytomembrane. However, further cell experiments verified that it was difficult to achieve desired results for drug-resistant human breast cancer (MCF-7 ADR) cells due to the reduced drug uptake and enhanced drug efflux. Interestingly, this multidrug resistance of MCF-7 ADR cells could be reversed after treated with near-infrared (NIR) light. This might ascribe to the hyperthermia generated by AuNRs under NIR, which suspended drug efflux process and led to excellent hyperthermia-assisted chemotherapy outcome. Overall, our studies suggested that AuNRs loaded reduction-sensitive HA nanogels were excellent candidates of drug carriers to reverse the drug-resistance and induce severe apoptosis of drug-resistant MCF-7 ADR cells.


Assuntos
Antineoplásicos/farmacologia , Doxorrubicina/farmacologia , Portadores de Fármacos/química , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Géis/química , Ácido Hialurônico/química , Antineoplásicos/química , Reagentes de Ligações Cruzadas/química , Cistamina/química , Doxorrubicina/química , Portadores de Fármacos/síntese química , Liberação Controlada de Fármacos , Géis/síntese química , Ouro/química , Ouro/efeitos da radiação , Calefação , Humanos , Ácido Hialurônico/síntese química , Raios Infravermelhos , Células MCF-7 , Nanotubos/química , Nanotubos/efeitos da radiação , Oxirredução
16.
Front Microbiol ; 10: 7, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30728809

RESUMO

Von Willebrand factor-binding protein (vWbp), secreted by Staphylococcus aureus (S. aureus), can activate host prothrombin, convert fibrinogen to fibrin clots, induce blood clotting, and contribute to pathophysiology of S. aureus-related diseases, including infective endocarditis, staphylococcal sepsis and pneumonia. Therefore, vWbp is an promising drug target in the treatment of S. aureus-related infections. Here, we report that dryocrassin ABBA (ABBA), a natural compound derived from Dryopteris crassirhizoma, can significantly inhibit the coagulase activity of vWbp in vitro by directly interacting with vWbp without killing the bacteria or inhibiting the expression of the vWbp. Using molecular dynamics simulations, we demonstrate that ABBA binds to the "central cavity" in the elbow of vWbp by interacting with Arg-70, His-71, Ala-72, Gly-73, Tyr-74, Glu-75, Tyr-83, and Gln-87 in vWbp, thus interfering with the binding of vWbp to prothrombin. Furthermore, in vivo studies demonstrated that ABBA can attenuate injury and inflammation of mouse lung tissues caused by S. aureus and increase survival of mice. Together these findings indicate that ABBA is a promising lead drug for the treatment of S. aureus-related infections. This is the first report of potential inhibitor which inhibit the coagulase activity of vWbp by directly interacting with vWbp.

17.
Colloids Surf B Biointerfaces ; 161: 279-287, 2018 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-29096372

RESUMO

The microbubble is a kind of clinically applied ultrasound contrast agent in disease diagnosis that can also rupture under sonication to increase membrane permeability and promote gene entry into targeted cells. However, the development of ultrasound-mediated gene delivery might be restricted because genes and microbubbles were separated and would not reach the targeted cells simultaneously. Herein, a kind of crosslinked positive microbubbles (CPMBs) were prepared to load DNA as gene vectors to promote gene delivery efficiency. The BSA shell of the CPMBs was crosslinked with disulfide bonds, which obviously enhanced the stability of the CPMBs. Furthermore, the CPMBs revealed sonoporation effects comparable to those of clinically applied SonoVue microbubbles. As DNA and CPMBs were electrostatically linked as an entirety, they would reach cells simultaneously. Thus, with the aid of ultrasound, these DNA-loaded microbubbles promoted DNA entry into cytoplasm more effectively and obtained higher cellular uptake efficiency and better transfection efficiency than DNA-mixed microbubbles. Confocal microscopy results showed that rupturing of the CPMBs/DNA entire microbubbles under sonication could carry DNA directly into the cytoplasm or nucleus. All results indicated that the cytocompatible DNA-loaded microbubbles have promising prospects in ultrasound-mediated gene delivery.


Assuntos
DNA/química , Microbolhas , Soroalbumina Bovina/química , Sonicação , Transfecção/métodos , Animais , Bovinos , Sobrevivência Celular , DNA/genética , DNA/metabolismo , Vetores Genéticos/genética , Vetores Genéticos/metabolismo , Células Hep G2 , Humanos , Microscopia Eletrônica de Varredura
18.
Chem Biol Drug Des ; 92(2): 1458-1467, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29671947

RESUMO

The antibiotic resistance (ARE) subfamily of ABC (ATP-binding cassette) proteins confers resistance to a variety of clinically important ribosome-targeting antibiotics and plays an important role in infections caused by pathogenic bacteria. However, inhibitors of ARE proteins have rarely been reported. Here, OptrA, a new member of the ARE proteins, was used to study inhibitors of these types of proteins. We first confirmed that destroying the catalytic activity of OptrA could restore the sensitivity of host cells to antibiotics. Then, fragment-based screening, a drug screening method, was used to screen for inhibitors of OptrA. The competitive saturation transfer difference experiments, docking, and molecular dynamics were used to determine the binding sites and mode of interactions between OptrA and fragment screening hits. In this study, we first find a novel and specific inhibitor of OptrA (CP1), which suppressed the ATPase activity of OptrA in vitro by 30%. A hydrogen bond formed between the 8-position phenylcyclic cyano group in CP1 and the amino acid residue Lys-271 allows CP1 to form a stable complex with OptrA protein. These findings provide a theoretical basis for the further optimization of the inhibitor structure to obtain inhibitors with higher efficiencies.


Assuntos
Transportadores de Cassetes de Ligação de ATP/antagonistas & inibidores , Antibacterianos/química , Proteínas de Bactérias/antagonistas & inibidores , Transportadores de Cassetes de Ligação de ATP/metabolismo , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/metabolismo , Proteínas de Bactérias/metabolismo , Sítios de Ligação , Domínio Catalítico , Cianetos/química , Cianetos/metabolismo , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Estrutura Terciária de Proteína
19.
Colloids Surf B Biointerfaces ; 157: 18-25, 2017 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-28558339

RESUMO

Recent research indicated that the morphology of nanoparticles could result in distinct biological behaviors, thus played an important role in designing efficient gene delivery systems. Among them, gold nanoparticles (AuNPs) with various shapes were widely studied due to the good biocompatibility and easy modification ability. Our recent research indicated that polyethyleneimine-g-bovine serum albumin (BSA-PEI) as non-viral gene vector showed good colloid stability and high transfection efficiency. In this work, BSA-PEI was utilized to modify gold nanospheres (AuNSs) and gold nanorods (AuNRs) to investigate the influence of the morphology on gene delivery. Both AuNS@BSA-PEI and AuNR@BSA-PEI nanoparticles condensed DNA effectively at N/P ratio above 5 and maintained spherical or rod-like morphology respectively. Due to the higher surface charge density at the tips, the rod-like gene complexes were prone to use the tips to contact with cell membrane, which facilitated to be uptaked by HepG2 cells. The endocytosis inhibition experiments showed some differences in the endocytic pathway. Gene transfection experiment showed that the rod-like complexes had almost 100-fold higher of transfection level than that of spherical complexes at the N/P ratio of 20. This work provided a potential strategy for further design of gene vectors with improved transfection results by adjusting the morphology of gene vectors.


Assuntos
Técnicas de Transferência de Genes , Ouro/química , Nanopartículas Metálicas/química , Nanotubos/química , Polietilenoimina/química , Soroalbumina Bovina/química , Vetores Genéticos/genética , Células Hep G2 , Humanos , Transfecção/métodos
20.
Colloids Surf B Biointerfaces ; 154: 133-141, 2017 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-28334690

RESUMO

Multifunctional nanoprobe was drawing increased attention in tumor diagnosis and therapy. The simple and effective establishment of the theranostic nanoplatforms was still under urgent need. Meanwhile, the targeting ability and morphology of nanoprobe were essential for the effective endocytosis, which could further affect the diagnosis. In this work, two morphologies of nanoprobes were fabricated using gold nanorods (AuNRs) and gold nanospheres (AuNSs). Thiolated-hyaluronic acid labeled with nile blue (HS-HA-NB), a near-infrared (NIR) fluorescence dye, was coated on the surface of the gold nanoparticles to form stable nanoprobes (AuNR@HS-HA-NB, AuNS@HS-HA-NB). The fluorescence of NB molecules quenched outside cells due to the fluorescence resonance energy transfer (FRET), and recovered after the HA degradation inside the cells. HA also could enhance cellular uptake in CD44 receptor highly expressed human breast carcinoma cells (MCF-7). In this way, bioprobes realized the MCF-7 cell images through intracellular fluorescent light-up. Comparing with the sphere bioprobe, the rod-shaped bioprobe dramatically promoted endocytosis to achieve a better diagnosis effect in a short time. After NIR light irradiation, severe MCF-7 apoptosis was observed with AuNR@HS-HA-NB existed. Our studies suggested that the AuNR@HS-HA-NB nanoparticles were the excellent candidates of versatile bioprobes to realize rapid, precise image and photothermal therapy to MCF-7 cells.


Assuntos
Técnicas Biossensoriais , Corantes Fluorescentes , Nanopartículas Metálicas , Fototerapia/métodos , Sobrevivência Celular , Endocitose , Ouro , Humanos , Ácido Hialurônico , Raios Infravermelhos/uso terapêutico , Células MCF-7 , Nanopartículas Metálicas/química , Nanopartículas Metálicas/ultraestrutura , Nanotubos/química , Nanotubos/ultraestrutura , Oxazinas , Nanomedicina Teranóstica/métodos
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