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1.
Proc Natl Acad Sci U S A ; 121(24): e2316419121, 2024 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-38830089

RESUMEN

The extinction of the woolly rhinoceros (Coelodonta antiquitatis) at the onset of the Holocene remains an enigma, with conflicting evidence regarding its cause and spatiotemporal dynamics. This partly reflects challenges in determining demographic responses of late Quaternary megafauna to climatic and anthropogenic causal drivers with available genetic and paleontological techniques. Here, we show that elucidating mechanisms of ancient extinctions can benefit from a detailed understanding of fine-scale metapopulation dynamics, operating over many millennia. Using an abundant fossil record, ancient DNA, and high-resolution simulation models, we untangle the ecological mechanisms and causal drivers that are likely to have been integral in the decline and later extinction of the woolly rhinoceros. Our 52,000-y reconstruction of distribution-wide metapopulation dynamics supports a pathway to extinction that began long before the Holocene, when the combination of cooling temperatures and low but sustained hunting by humans trapped woolly rhinoceroses in suboptimal habitats along the southern edge of their range. Modeling indicates that this ecological trap intensified after the end of the last ice age, preventing colonization of newly formed suitable habitats, weakening stabilizing metapopulation processes, triggering the extinction of the woolly rhinoceros in the early Holocene. Our findings suggest that fragmentation and resultant metapopulation dynamics should be explicitly considered in explanations of late Quaternary megafauna extinctions, sending a clarion call to the fragility of the remaining large-bodied grazers restricted to disjunct fragments of poor-quality habitat due to anthropogenic environmental change.


Asunto(s)
Extinción Biológica , Fósiles , Perisodáctilos , Dinámica Poblacional , Animales , Ecosistema , ADN Antiguo/análisis , Paleontología
2.
Proc Natl Acad Sci U S A ; 121(20): e2318384121, 2024 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-38713627

RESUMEN

The reaction kinetics of photocatalytic CO2 reduction is highly dependent on the transfer rate of electrons and protons to the CO2 molecules adsorbed on catalytic centers. Studies on uncovering the proton effect in catalysts on photocatalytic activity of CO2 reduction are significant but rarely reported. In this paper, we, from the molecular level, revealed that the photocatalytic activity of CO2 reduction is closely related to the proton availability in catalysts. Specifically, four dinuclear Co(II) complexes based on Robson-type ligands with different number of carboxylic groups (-nCOOH; n = 0, 2, 4, 6) were designed and synthesized. All these complexes show photocatalytic activity for CO2 reduction to CO in a water-containing system upon visible-light illumination. Interestingly, the CO yields increase positively with the increase of the carboxylic-group number in dinuclear Co(II) complexes. The one containing -6COOH shows the best photocatalytic activity for CO2 reduction to CO, with the TON value reaching as high as 10,294. The value is 1.8, 3.4, and 7.8 times higher than those containing -4COOH, -2COOH, and -0COOH, respectively. The high TON value also makes the dinuclear Co(II) complex with -6COOH outstanding among reported homogeneous molecular catalysts for photocatalytic CO2 reduction. Control experiments and density functional theory calculation indicated that more carboxylic groups in the catalyst endow the catalyst with more proton relays, thus accelerating the proton transfer and boosting the photocatalytic CO2 reduction. This study, at a molecular level, elucidates that more carboxylic groups in catalysts are beneficial for boosting the reaction kinetics of photocatalytic CO2 reduction.

3.
Brief Bioinform ; 25(1)2023 11 22.
Artículo en Inglés | MEDLINE | ID: mdl-38243692

RESUMEN

Combination therapy has exhibited substantial potential compared to monotherapy. However, due to the explosive growth in the number of cancer drugs, the screening of synergistic drug combinations has become both expensive and time-consuming. Synergistic drug combinations refer to the concurrent use of two or more drugs to enhance treatment efficacy. Currently, numerous computational methods have been developed to predict the synergistic effects of anticancer drugs. However, there has been insufficient exploration of how to mine drug and cell line data at different granularity levels for predicting synergistic anticancer drug combinations. Therefore, this study proposes a granularity-level information fusion strategy based on the hypergraph transformer, named HypertranSynergy, to predict synergistic effects of anticancer drugs. HypertranSynergy introduces synergistic connections between cancer cell lines and drug combinations using hypergraph. Then, the Coarse-grained Information Extraction (CIE) module merges the hypergraph with a transformer for node embeddings. In the CIE module, Contranorm is a normalization layer that mitigates over-smoothing, while Gaussian noise addresses local information gaps. Additionally, the Fine-grained Information Extraction (FIE) module assesses fine-grained information's impact on predictions by employing similarity-aware matrices from drug/cell line features. Both CIE and FIE modules are integrated into HypertranSynergy. In addition, HypertranSynergy achieved the AUC of 0.93${\pm }$0.01 and the AUPR of 0.69${\pm }$0.02 in 5-fold cross-validation of classification task, and the RMSE of 13.77${\pm }$0.07 and the PCC of 0.81${\pm }$0.02 in 5-fold cross-validation of regression task. These results are better than most of the state-of-the-art models.


Asunto(s)
Antineoplásicos , Antineoplásicos/farmacología , Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Línea Celular , Terapia Combinada , Combinación de Medicamentos
4.
Plant Physiol ; 2024 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-39041412

RESUMEN

Arabidopsis (Arabidopsis thaliana) HISTONE DEACETYLASE 6 (HDA6) and HISTONE DEMETHYLASES LSD-LIKE 1 (LDL1) and LDL2 synergistically regulate the expression of long non-coding RNAs associated with H3Ac and H3K4me2. The underlying mechanisms of such highly coordinated interactions among genetic and epigenetic factors contributing to this collaborative regulation remain largely unclear. We analyzed all transposable elements (TEs) across the Arabidopsis genome and the individual and combined roles of HDA6 and LDL1/LDL2 by dissecting multi-layered epigenomes and their association with transcription. Instead of an individual synergistic effect, we observed dual synergistic and antagonistic effects, which are positively associated with H3Ac and H3K4me2 while maintaining a negative but moderate association with DNA methylation. Specifically, two modes of synergistic regulation were discovered in TEs: 74% are primarily regulated by HDA6, with less dependence on LDL1/LDL2, and the remaining 26% are co-regulated by both. Between the two modes, we showed that HDA6 has a strong effect on TE silencing, whereas LDL1/LDL2 plays a weaker yet crucial role in co-regulation with HDA6. Our results led to a model of epigenomic regulation - the differential de-repression between the two modes of synergistic regulation of TEs was determined by H3Ac and H3K4me2 levels, where TEs are in accessible chromatins free of DNA methylation, and this open chromatin environment precedes transcriptional changes and epigenome patterning. Our results discovered unbalanced effects of genetic factors in synergistic regulation through delicately coordinated multi-layered epigenomes and chromatin accessibility.

5.
Genomics ; 116(5): 110890, 2024 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-38909906

RESUMEN

Previous studies have presented evidence suggesting that altitude exerts detrimental effects on reproductive processes, yet the underlying mechanism remains elusive. Our study employed two distinct goat breeds inhabiting low and high altitudes, and conducted a comparative analysis of mRNA profiles in testis tissues and the composition of gut microbiota. The results revealed a reduced testis size in high-altitude goats. RNA-seq analysis identified the presence of 214 differentially expressed genes (DEGs) in the testis. These DEGs resulted in a weakened immunosuppressive effect, ultimately impairing spermatogenesis in high-altitude goats. Additionally, 16S rDNA amplicon sequencing recognized statistically significant variations in the abundance of the genera Treponema, unidentified_Oscillospiraceae, Desulfovibrio, Butyricicoccus, Dorea, Parabacteroides between the two groups. The collective evidence demonstrated the gut and testis played a synergistic role in causing decreased fertility at high altitudes. Our research provides a theoretical basis for future investigations into the reproductive fitness of male goats.

6.
Nano Lett ; 24(4): 1197-1204, 2024 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-38227967

RESUMEN

Electrocatalytic reduction of nitrate to ammonia (NO3RR) is gaining attention for low carbon emissions and environmental protection. However, low ammonia production rate and poor selectivity have remained major challenges in this multi-proton coupling process. Herein, we report a facile strategy toward a novel Fe-based hybrid structure composed of Fe single atoms and Fe3C atomic clusters that demonstrates outstanding performance for synergistic electrocatalytic NO3RR. By operando synchrotron Fourier transform infrared spectroscopy and theoretical computation, we clarify that Fe single atoms serve as the active site for NO3RR, while Fe3C clusters facilitate H2O dissociation to provide protons (*H) for continued hydrogenation reactions. As a result, the Fe-based electrocatalyst exhibits ammonia Faradaic efficiency of nearly 100%, with a corresponding production rate of 24768 µg h-1 cm-2 at -0.4 V vs RHE, exceeding most reported metal-based catalysts. This research provides valuable guidance toward multi-step reactions.

7.
Nano Lett ; 24(28): 8752-8762, 2024 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-38953881

RESUMEN

Acute methicillin-resistant Staphylococcus aureus (MRSA) pneumonia is a common and serious lung infection with high morbidity and mortality rates. Due to the increasing antibiotic resistance, toxicity, and pathogenicity of MRSA, there is an urgent need to explore effective antibacterial strategies. In this study, we developed a dry powder inhalable formulation which is composed of porous microspheres prepared from poly(lactic-co-glycolic acid) (PLGA), internally loaded with indocyanine green (ICG)-modified, heat-resistant phages that we screened for their high efficacy against MRSA. This formulation can deliver therapeutic doses of ICG-modified active phages to the deep lung tissue infection sites, avoiding rapid clearance by alveolar macrophages. Combined with the synergistic treatment of phage therapy and photothermal therapy, the formulation demonstrates potent bactericidal effects in acute MRSA pneumonia. With its long-term stability at room temperature and inhalable characteristics, this formulation has the potential to be a promising drug for the clinical treatment of MRSA pneumonia.


Asunto(s)
Staphylococcus aureus Resistente a Meticilina , Copolímero de Ácido Poliláctico-Ácido Poliglicólico , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Animales , Ratones , Copolímero de Ácido Poliláctico-Ácido Poliglicólico/química , Microesferas , Terapia Fototérmica , Neumonía Estafilocócica/terapia , Terapia de Fagos/métodos , Verde de Indocianina/química , Verde de Indocianina/farmacología , Verde de Indocianina/uso terapéutico , Verde de Indocianina/administración & dosificación , Antibacterianos/química , Antibacterianos/farmacología , Antibacterianos/administración & dosificación , Antibacterianos/uso terapéutico , Administración por Inhalación , Humanos , Bacteriófagos/química
8.
Nano Lett ; 24(15): 4610-4617, 2024 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-38564191

RESUMEN

The intricate protonation process in carbon dioxide reduction usually makes the product unpredictable. Thus, it is significant to control the reactive intermediates to manipulate the reaction steps. Here, we propose that the synergistic La-Ti active sites in the N-La2Ti2O7 nanosheets enable the highly selective carbon dioxide photoreduction into methane. In the photoreduction of CO2 over N-La2Ti2O7 nanosheets, in situ Fourier transform infrared spectra are utilized to monitor the *CH3O intermediate, pivotal for methane production, whereas such monitoring is not conducted for La2Ti2O7 nanosheets. Also, theoretical calculations testify to the increased charge densities on the Ti and La atoms and the regulated formation energy barrier of *CO and *CH3O intermediates by the constructed synergistic active sites. Accordingly, the methane formation rate of 7.97 µL h-1 exhibited by the N-La2Ti2O7 nanosheets, along with an electron selectivity of 96.6%, exceeds that of most previously reported catalysts under similar conditions.

9.
Nano Lett ; 24(26): 8134-8142, 2024 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-38900138

RESUMEN

Developing highly efficient and carbon monoxide (CO)-tolerant platinum (Pt) catalysts for the formic acid oxidation reaction (FAOR) is vital for direct formic acid fuel cells (DFAFCs), yet it is challenging due to the high energy barrier of direct intermediates (HCOO* and COOH*) as well as the CO poisoning issues associated with Pt alloy catalysts. Here we present a versatile biphasic strategy by creating a hexagonal/cubic crystalline-phase-synergistic PtPb/C (h/c-PtPb/C) catalyst to tackle the aforementioned issues. Detailed investigations reveal that h/c-PtPb/C can simultaneously facilitate the adsorption of direct intermediates while inhibiting CO adsorption, thereby significantly improving the activation and CO spillover. As a result, h/c-PtPb/C showcases an outstanding FAOR activity of 8.1 A mgPt-1, which is 64.5 times higher than that of commercial Pt/C and significantly surpasses monophasic PtPb. Moreover, the h/c-PtPb/C-based membrane electrode assembly exhibits an exceptional peak power density of 258.7 mW cm-2 for practical DFAFC applications.

10.
Nano Lett ; 24(26): 8046-8054, 2024 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-38912748

RESUMEN

Bacteria invasion is the main factor hindering the wound-healing process. However, current antibacterial therapies inevitably face complex challenges, such as the abuse of antibiotics or severe inflammation during treatment. Here, a drug-free bioclay enzyme (Bio-Clayzyme) consisting of Fe2+-tannic acid (TA) network-coated kaolinite nanoclay and glucose oxidase (GOx) was reported to destroy harmful bacteria via bimetal antibacterial therapy. At the wound site, Bio-Clayzyme was found to enhance the generation of toxic hydroxyl radicals for sterilization via cascade catalysis of GOx and Fe2+-mediated peroxidase mimetic activity. Specifically, the acidic characteristics of the infection microenvironment accelerated the release of Al3+ from kaolinite, which further led to bacterial membrane damage and amplified the antibacterial toxicity of Fe2+. Besides, Bio-Clayzyme also performed hemostasis and anti-inflammatory functions inherited from Kaol and TA. By the combination of hemostasis and anti-inflammatory and bimetal synergistic sterilization, Bio-Clayzyme achieves efficient healing of infected wounds, providing a revolutionary approach for infectious wound regeneration.


Asunto(s)
Antibacterianos , Glucosa Oxidasa , Cicatrización de Heridas , Glucosa Oxidasa/química , Glucosa Oxidasa/metabolismo , Glucosa Oxidasa/farmacología , Cicatrización de Heridas/efectos de los fármacos , Antibacterianos/farmacología , Antibacterianos/química , Animales , Esterilización/métodos , Arcilla/química , Infección de Heridas/tratamiento farmacológico , Infección de Heridas/microbiología , Hierro/química
11.
Nano Lett ; 24(4): 1268-1276, 2024 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-38241736

RESUMEN

While quasi-two-dimensional (quasi-2D) perovskites have good properties of cascade energy transfer, high exciton binding energy, and high quantum efficiency, which will benefit high-efficiency blue PeLEDs, inefficient domain distribution management and unbalanced carrier transport impede device performance improvement. Herein, (2-(9H-carbazol-9-yl)ethyl)phosphonic acid (2PACz) and methyl 2-aminopyridine-4-carboxylate (MAC) were simultaneously introduced to a blue quasi-2D perovskite film. Relying on the synergistic effect of 2PACz and MAC, it not only modulates the phase distribution inhibiting the n = 2 phase but also greatly improves the electrical property of the quasi-2D perovskite film. As a result, the as-modified blue quasi-2D PeLED demonstrated an external quantum efficiency (EQE) of 17.08% and a luminance of 10142 cd m-2. This study exemplifies the synergistic effect among dual additives and offers a new effective additive strategy modulating phase distribution and building balanced carrier transport, which paves the way for the fabrication of highly efficient blue PeLEDs.

12.
Nano Lett ; 24(10): 3249-3256, 2024 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-38477055

RESUMEN

The synergistic interaction between the isolated metal sites promoted the electrocatalytic activity of the catalysts. However, the structural heterogeneity of the isolated sites makes it challenging to evaluate this effect accurately. In this work, metal-coordinated polyphthalocyanine molecules (Fe-PPc, Co-PPc, FeCo-PPc) with long-range ordered and precise coordination structures are used as a platform to study the synergies of different isolated metal sites in the electrochemical CO2 reduction reaction. The combination means of experimental and theoretical calculation clearly reveal that the coexistence of Fe and Co sites in PPc significantly enhances the conjugation effect of the macrocycle. This enhancement subsequently causes the metal sites to lose more electrons, thereby improving their adsorption of CO2 and facilitating the formation of intermediate *COOH on them. As a result, FeCo-PPc achieves a CO partial current density of about 57.4 mA/cm2 with a high turnover frequency of over 49000 site-1 h-1 at -0.9 V (vs RHE).

13.
BMC Bioinformatics ; 25(1): 140, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38561679

RESUMEN

Drug combination therapy is generally more effective than monotherapy in the field of cancer treatment. However, screening for effective synergistic combinations from a wide range of drug combinations is particularly important given the increase in the number of available drug classes and potential drug-drug interactions. Existing methods for predicting the synergistic effects of drug combinations primarily focus on extracting structural features of drug molecules and cell lines, but neglect the interaction mechanisms between cell lines and drug combinations. Consequently, there is a deficiency in comprehensive understanding of the synergistic effects of drug combinations. To address this issue, we propose a drug combination synergy prediction model based on multi-source feature interaction learning, named MFSynDCP, aiming to predict the synergistic effects of anti-tumor drug combinations. This model includes a graph aggregation module with an adaptive attention mechanism for learning drug interactions and a multi-source feature interaction learning controller for managing information transfer between different data sources, accommodating both drug and cell line features. Comparative studies with benchmark datasets demonstrate MFSynDCP's superiority over existing methods. Additionally, its adaptive attention mechanism graph aggregation module identifies drug chemical substructures crucial to the synergy mechanism. Overall, MFSynDCP is a robust tool for predicting synergistic drug combinations. The source code is available from GitHub at https://github.com/kkioplkg/MFSynDCP .


Asunto(s)
Benchmarking , Entrenamiento Simulado , Combinación de Medicamentos , Quimioterapia Combinada , Línea Celular
14.
Med Res Rev ; 2024 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-38769656

RESUMEN

Oncogenes and tumor suppressors are well-known to orchestrate several signaling cascades, regulate extracellular and intracellular stimuli, and ultimately control the fate of cancer cells. Accumulating evidence has recently revealed that perturbation of these key modulators by mutations or abnormal protein expressions are closely associated with drug resistance in cancer therapy; however, the inherent drug resistance or compensatory mechanism remains to be clarified for targeted drug discovery. Thus, dual-target drug development has been widely reported to be a promising therapeutic strategy for improving drug efficiency or overcoming resistance mechanisms. In this review, we provide an overview of the therapeutic strategies of dual-target drugs, especially focusing on pharmacological small-molecule compounds in cancer, including small molecules targeting mutation resistance, compensatory mechanisms, synthetic lethality, synergistic effects, and other new emerging strategies. Together, these therapeutic strategies of dual-target drugs would shed light on discovering more novel candidate small-molecule drugs for the future cancer treatment.

15.
Proteins ; 2024 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-39158131

RESUMEN

When two proteins bind to each other, this process is often accompanied by a change in their structural states (from disordered to ordered or vice versa). As it turns out, there are 10 distinct possibilities for such binding-related order/disorder transitions. Out of this number, seven scenarios have been experimentally observed, while another three remain hitherto unreported. As an example, we discuss the so-called mutual synergistic folding, whereby two disordered proteins come together to form a fully structured complex. Our bioinformatics analysis of the Protein Databank found potential new examples of this remarkable binding mechanism.

16.
Curr Issues Mol Biol ; 46(6): 5551-5560, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38921003

RESUMEN

Extensive research on medicinal herbs for bioactive compounds proposes that they could replace synthetic drugs, reducing side effects and economic burdens. Especially, interest in the synergistic benefits of natural products is increasing, implying that their combined use may enhance therapeutic effectiveness. This study aimed to explore the synergetic effects of turmeric (Curcuma longa L.) and black pepper (Piper nigrum L.) extract on lung normal (MRC-5) and cancer (A549 and NCI-H292) cell lines. The turmeric extract (TM) only affected the lung cancer cell lines, but it had no impact on the MRC-5 cell line. On the other hand, the black pepper extract (BP) did not cause any damage to either the lung normal or cancer cell lines, even at concentrations of up to 400 µg/mL. Response surface methodology was used to predict the ideal synergistic concentrations (EC50) of TM and BP, which were found to be 48.5 and 241.7 µg/mL, respectively. Notably, the selected condition resulted in higher cytotoxicity compared to the exposure to TM alone, indicating a potent synergetic effect. The rate of curcumin degradation under this combined treatment was significantly decreased to 49.72 ± 5.00 nmol/h/µg for A549 cells and 47.53 ± 4.78 nmol/h/µg for NCI-H292 cells, respectively, as compared to curcumin alone. Taken together, this study confirmed the potent synergistic effect of TM and BP on lung cancer cell lines. Further research is required to identify their specific synergetic mechanisms. Our findings provide crucial foundational data on the synergistic effects of TM and BP.

17.
Curr Issues Mol Biol ; 46(2): 1516-1529, 2024 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-38392216

RESUMEN

Carcinogens, such as arecoline, play a crucial role in cancer progression and continuous gene mutations by generating reactive oxygen species (ROS). Antioxidants can reduce ROS levels and potentially prevent cancer progression but may paradoxically enhance the survival of cancer cells. This study investigated whether epigallocatechin-3-gallate (EGCG), an antioxidant from green tea, could resolve this paradox. Prostate cancer cells (PC-3 cell line) were cultured and treated with arecoline combined with NAC (N-acetylcysteine) or EGCG; the combined effects on intracellular ROS levels and cell viability were examined using the MTT and DCFDA assays, respectively. In addition, apoptosis, cell cycle, and protein expression were investigated using flow cytometry and western blot analysis. Our results showed that EGCG, similar to NAC (N-acetylcysteine), reduced the intracellular ROS levels, which were elevated by arecoline. Moreover, EGCG not only caused cell cycle arrest but also facilitated cell apoptosis in arecoline-treated cells in a synergistic manner. These were evidenced by elevated levels of cyclin B1 and p27, and increased fragmentation of procaspase-3, PARP, and DNA. Our findings highlight the potential use of EGCG for cancer prevention and therapy.

18.
Am J Epidemiol ; 2024 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-38932557

RESUMEN

Air pollution and noise exposure may synergistically contribute to increased cardiometabolic disorders; however, few studies have examined this potential interaction nor considered exposures beyond residential location. This study investigates the combined impact of dynamic air pollution and transportation noise on cardiometabolic disorders in San Diego County. Using the Community of Mine Study (2014-2017), 602 ethnically diverse participants were assessed for obesity, dyslipidemia, hypertension, and metabolic syndrome (MetS) using anthropometric measurements and biomarkers from blood samples. Time-weighted measures of exposure to PM2.5, NO2, road and aircraft noise were calculated using global positioning system (GPS) mobility data and Kernel Density Estimation. Generalized estimating equation models were used to analyze associations. Interactions were assessed on the multiplicative and additive scales using relative excess risk due to interaction (RERI). We found that air pollution and noise interact to affect metabolic disorders on both multiplicative and additive scales. The effect of noise on obesity and MetS was higher when air pollution was higher. The RERI of aircraft noise and NO2 on obesity and MetS were 0.13 (95%CI 0.03, 0.22) and 0.13 (95%CI 0.02, 0.25), respectively. This finding suggests that aircraft noise and air pollution may have synergistic effects on obesity and MetS.

19.
Antimicrob Agents Chemother ; : e0044824, 2024 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-38742904

RESUMEN

Phage-antibiotic combination treatment is a novel noteworthy drug delivery method in anti-infection. In the current study, we have isolated a new phage, pB23, against carbapenem-resistant Acinetobacter baumannii 2023. Synergistic antibacterial effect between phage pB23 and meropenem combination could be more stable, using moderate doses of phage (multiplicity of infection ranging from 0.1 to 1,000) based on results of in vitro antibacterial activity. Phage pB23 and meropenem combination could effectively clear mature biofilms and prevent biofilm formation of carbapenem-resistant Acinetobacter baumannii in vitro. Phage pB23 and meropenem combination also has good synergistic antibacterial effects against carbapenem-resistant Acinetobacter baumannii in different growth phases under static culture conditions. The pig skin explant model shows that phage pB23 and meropenem combination has a synergistic effect to remove bacteria from wounds ex vivo. Phage pB23 and meropenem combination also exhibited a synergistic antibacterial effect in vivo using a zebrafish infection mode. The potential promotion of phage proliferation by meropenem and the sensitivity recovery of phage-resistant bacteria to meropenem might elucidate the mechanism of the synergistic antimicrobial activity. In summary, our study illustrates that phage pB23 and meropenem combination could produce synergistic antibacterial effects against carbapenem-resistant Acinetobacter baumannii under static growth conditions. This study also demonstrates that phage-antibiotic combination will become an effective strategy to enhance antibacterial activity of individual drug and provide a new idea of the drug development for the treatment of infections due to carbapenem-resistant Acinetobacter baumannii and other multidrug-resistant bacteria.

20.
Antimicrob Agents Chemother ; 68(4): e0095623, 2024 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-38446062

RESUMEN

Viral RNA-dependent RNA polymerase (RdRp), a highly conserved molecule in RNA viruses, has recently emerged as a promising drug target for broad-acting inhibitors. Through a Vero E6-based anti-cytopathic effect assay, we found that BPR3P0128, which incorporates a quinoline core similar to hydroxychloroquine, outperformed the adenosine analog remdesivir in inhibiting RdRp activity (EC50 = 0.66 µM and 3 µM, respectively). BPR3P0128 demonstrated broad-spectrum activity against various severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern. When introduced after viral adsorption, BPR3P0128 significantly decreased SARS-CoV-2 replication; however, it did not affect the early entry stage, as evidenced by a time-of-drug-addition assay. This suggests that BPR3P0128's primary action takes place during viral replication. We also found that BPR3P0128 effectively reduced the expression of proinflammatory cytokines in human lung epithelial Calu-3 cells infected with SARS-CoV-2. Molecular docking analysis showed that BPR3P0128 targets the RdRp channel, inhibiting substrate entry, which implies it operates differently-but complementary-with remdesivir. Utilizing an optimized cell-based minigenome RdRp reporter assay, we confirmed that BPR3P0128 exhibited potent inhibitory activity. However, an enzyme-based RdRp assay employing purified recombinant nsp12/nsp7/nsp8 failed to corroborate this inhibitory activity. This suggests that BPR3P0128 may inhibit activity by targeting host-related RdRp-associated factors. Moreover, we discovered that a combination of BPR3P0128 and remdesivir had a synergistic effect-a result likely due to both drugs interacting with separate domains of the RdRp. This novel synergy between the two drugs reinforces the potential clinical value of the BPR3P0128-remdesivir combination in combating various SARS-CoV-2 variants of concern.


Asunto(s)
Adenosina Monofosfato/análogos & derivados , Alanina/análogos & derivados , COVID-19 , Pirazoles , Quinolinas , Humanos , SARS-CoV-2/metabolismo , ARN Polimerasa Dependiente del ARN/metabolismo , Simulación del Acoplamiento Molecular , Tratamiento Farmacológico de COVID-19 , Antivirales/química
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