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1.
Toxicol Appl Pharmacol ; 492: 117118, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39362309

RESUMO

Bisphenol A (BPA) is among the extensively researched environmental endocrine-disrupting chemicals (EDCs), and its utilization is restricted owing to the detrimental impacts it has on human health. Bisphenol AP (BPAP) is one of the alternatives to BPA, but the influence of BPAP on human health has not been elucidated. The objective of the current research was to determine the influence of BPAP exposure on the in vitro maturation of mouse oocytes and to explore its potential reproductive toxicity. BPAP exposure was found to inhibit polar body extrusion during mouse oocyte maturation, resulting in an arrest at the metaphase I stage of meiosis. Exposure to BPAP led to sustained activation of BubR1, preventing the degradation of both Securin and Cyclin B1. Mechanistically, BPAP exposure disrupts spindle assembly and chromosome alignment. Levels of acetylated α-tubulin were significantly elevated in BPAP-treated oocytes, reflecting decreased spindle stability. Exposure to BPAP also induced DNA damage and impaired DNA damage repair. In addition, BPAP exposure altered histone modification levels. In summary, this investigation suggests that exposure to BPAP can influence cytoskeletal assembly, interfere with cell cycle progression, induce DNA damage, alter histone modifications, and ultimately impede oocyte meiotic maturation. This investigation enhances understanding of the impact of bisphenol analogs on female gametes, underscoring that BPAP cannot be considered a reliable replacement for BPA.

2.
Org Lett ; 2024 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-39373662

RESUMO

Constructing a C-N bond by merging electrochemistry and nickel catalysis is considered a powerful strategy. Herein, we investigate highly efficient intramolecular amination at room temperature with excellent functional group tolerance. Mechanistic studies suggest that the rapid ligand exchange may lead to the NiI/NiIII catalytic cycle. This method not only provides a new perspective for intramolecular amination but also offers a novel approach for constructing the benzothiazole scaffold.

3.
ACS Nano ; 2024 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-39248347

RESUMO

The rapid diffusion kinetics and smallest ion radius make protons the ideal cations toward the ultimate energy storage technology combining the ultrafast charging capabilities of supercapacitors and the high energy densities of batteries. Despite the concept existing for centuries, the lack of satisfactory electrode materials hinders its practical development. Recently, the rapid advancement of the emerging two-dimensional (2D) materials, characterized by their ultrathin morphology, interlayer van der Waals gaps, and distinctive electrochemical properties, injects promises into future proton-based energy storage systems. In this perspective, we comprehensively summarize the current advances in proton-based energy storage based on 2D materials. We begin by providing an overview of proton-based energy storage systems, including proton batteries, pseudocapacitors and electrical double layer capacitors. We then elucidate the fundamental knowledge about proton transport characteristics, including in electrolytes, at electrolyte/electrode interfaces, and within electrode materials, particularly in 2D material systems. We comprehensively summarize specific cases of 2D materials as proton electrodes, detailing their design concepts, proton transport mechanism and electrochemical performance. Finally, we provide insights into the prospects of proton-based energy storage systems, emphasizing the importance of rational design of 2D electrode materials and matching electrolyte systems.

4.
Polymers (Basel) ; 16(17)2024 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-39274079

RESUMO

Stepwise photopolymerization is a miraculous strategy modulating the polymer skeleton and electro-optical properties of light modulators based on liquid crystal/polymer composites. However, owing to the indistinct polymerization mechanism and curing condition discrepancy, the required polymer structures and electro-optical properties are hard to be controlled precisely. Herein, a novel polymer-stabilized liquid crystal film based on acrylate/epoxy resin is proposed, fabricated and the relationships between preparation process, polymer content, polymer morphology and electro-optical properties are studied. The in-situ photopolymerization of acrylate/epoxy resin liquid crystalline polymer is fulfilled using cation photo-initiator UV 6976. The distinct photopolymerization speed between acrylate and epoxy resin benefits the polymer morphology control, and with accurate containment of the polymerization process and polymer composition, the superior electro-optical properties at a higher polymer content are acquired. The polymer morphology and electro-optical properties are influenced by the polymer content and mass ratio between acrylate and epoxy resin. The best electro-optical properties among samples are attained by controlling the mass ratio between acrylate and epoxy resin to 1:1, integrating higher densities of scattering centers and lower anchoring effect. With higher polymer content, the strategy of increasing the mass ratio of E6M benefits the improvement of E-O properties for alleviating polymer density. This work provides insights to stepwise polymerization of liquid crystalline monomers and offers a fancy strategy for the preparation of novel liquid crystal dimming films.

5.
Food Chem Toxicol ; : 115024, 2024 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-39341490

RESUMO

Methylmercury chloride (MMC) is a persistent heavy metal contaminant that can bioaccumulate in humans via the food chain, exerting detrimental effects on health. Nevertheless, the specific influence of MMC on oocyte meiotic maturation has yet to be elucidated. This research demonstrated that MMC exposure during the in vitro cultivation of mouse oocytes did not influence germinal vesicle breakdown but markedly decreased oocyte maturation rates. Subsequent analysis indicated that MMC exposure resulted in aberrant spindle morphology and disorganized chromosome alignment, alongside continuous activation of the spindle assembly checkpoint (SAC). However, MMC exposure didn't alter the localization pattern of microtubule-organizing center-associated proteins. MMC exposure considerably diminished the acetylation level of α-tubulin, signifying reduced microtubule stability. Additionally, MMC exposure disrupted the dynamic alterations of F-actin. MMC exposure didn't affect mitochondrial localization, mitochondrial membrane potential, adenosine triphosphate content or the concentrations of reactive oxygen species. Nonetheless, MMC exposure triggered DNA damage and modified histone modification levels. Consequently, the defects in oocyte maturation induced by MMC exposure can be attributed to impaired cytoskeleton dynamics and DNA damage. This study offers the first comprehensive elucidation of the negative impacts of MMC on oocyte maturation, highlighting the potential reproductive health risks associated with MMC exposure.

6.
Heliyon ; 10(12): e32556, 2024 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-39183864

RESUMO

Given the physiological function and anatomical location of the reproductive tract, studying the upper reproductive tract microbiota may be essential for studying male infertility and other male diseases. This study aimed to characterize the microbiota of the upper reproductive tract male rats and investigate whether specific microbial compositions are associated with sperm parameters. 16S rRNA gene sequencing was used to characterize the microbial composition in the testis, epididymis, seminal vesicles, vas deferens and prostate tissues of the rats. The results showed significant enrichment of Methyloperoxococcus spp. in testicular tissues, Jeotgalicoccus spp. in epididymal tissues. Spearman's correlation analysis revealed that the abundance of several bacterial genera in epididymal, testicular, and seminal vesicle gland tissues correlated with several sperm activity parameters. Our findings provide detailed information on characterizing the upper reproductive tract microbiome in male rats, as well as a potentially crucial link between the reproductive system microbiota and sperm quality.

7.
Bioorg Chem ; 151: 107712, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39146761

RESUMO

Ketolides (3-keto) such as TE-802 and acylides (3-O-acyl) like TEA0929 are ineffective against constitutively resistant pathogens harboring erythromycin ribosomal methylation (erm) genes. Following our previous work on alkylides (3-O-alkyl), we explored the structure-activity relationships of hybrids combining (R/S) 3-descladinosyl erythromycin with 6/7-quinolone motifs, featuring extended ether-linked spacers, with a focus on their efficacy against pathogens bearing constitutive erm gene resistance. Optimized compounds 17a and 31f not only reinstated efficacy against inducibly resistant pathogens but also demonstrated significantly augmented activities against constitutively resistant strains of Streptococcus pneumoniae and Streptococcus pyogenes, which are typically refractory to existing C-3 modified macrolides. Notably, hybrid 31f (coded ZN-51) represented a pioneering class of agents distinguished by its dual modes of action, with ribosomes as the primary target and topoisomerases as the secondary target. As a novel chemotype of macrolide-quinolone hybrids, alkylide 31f is a valuable addition to our armamentarium against macrolide-resistant bacteria.


Assuntos
Antibacterianos , Macrolídeos , Testes de Sensibilidade Microbiana , Quinolonas , Streptococcus pneumoniae , Relação Estrutura-Atividade , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/síntese química , Quinolonas/química , Quinolonas/farmacologia , Quinolonas/síntese química , Macrolídeos/química , Macrolídeos/farmacologia , Streptococcus pneumoniae/efeitos dos fármacos , Estrutura Molecular , Desenho de Fármacos , Streptococcus pyogenes/efeitos dos fármacos , Streptococcus pyogenes/enzimologia , Relação Dose-Resposta a Droga , Éteres/química , Éteres/farmacologia , Éteres/síntese química
8.
Sci Rep ; 14(1): 18472, 2024 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-39122757

RESUMO

There is a relative scarcity of large-scale population studies investigating the relationship between the insulin resistance index of homeostasis model assessment (HOMA-IR) and vascular damage. Therefore, we assessed the association between HOMA-IR and vascular damage in adults aged 18 years and older in China. A total of 17,985 research subjects were included. Vascular damage markers and relevant laboratory tests were measured. HOMA-IR was calculated as (fasting insulin * fasting blood glucose)/22.5. Vascular damage included arteriosclerosis (ba-PWV > 1800 cm/s), peripheral artery disease (ABI < 0.9), and microalbuminuria (UACR > 30 mg/g). The relationship between HOMA-IR and vascular damage was analyzed using the RCS. The restricted cubic spline (RCS) analysis suggested that HOMA-IR was nonlinearly associated with arteriosclerosis (P for no-liner < 0.01), peripheral artery disease (P for no-liner < 0.01), and microalbuminuria (P for no-liner < 0.01). Further segmented regression analyses revealed that in study subjects with HOMA-IR < 5, we found that HOMA-IR was associated with an increased OR for arteriosclerosis (OR: 1.36, 95% CI (1.28, 1.45), P < 0.01), peripheral artery disease (OR: 1.33, 95% CI (1.10, 1.60), P < 0.01) and microalbuminuria (OR: 1.59, 95% CI (1.49, 1.70), P < 0.01). HOMA-IR is an independent risk factor for vascular damage, both macrovascular and microvascular. The phenomenon of saturation of HOMA-IR with vascular damage needs further investigation.


Assuntos
Resistência à Insulina , Humanos , Masculino , China/epidemiologia , Feminino , Estudos Transversais , Pessoa de Meia-Idade , Adulto , Idoso , Albuminúria , Fatores de Risco , Doença Arterial Periférica/epidemiologia , Doença Arterial Periférica/etiologia , Glicemia/metabolismo , Arteriosclerose/patologia , Arteriosclerose/epidemiologia , Insulina/sangue , Insulina/metabolismo
9.
J Med Chem ; 67(18): 16556-16575, 2024 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-39196895

RESUMO

Bacterial RNA polymerase (RNAP), the core enzyme responsible for bacterial transcription, requires the NusG factor for efficient transcription elongation and termination. As the primary binding site for NusG, the RNAP clamp-helix (CH) domain represents a potential protein-protein interaction (PPI) target for novel antimicrobial agent design and discovery. In this study, we designed a pharmacophore model based on the essential amino acids of the CH for binding to NusG, such as R270, R278, and R281 (Escherichia coli numbering), and identified a hit compound with mild antimicrobial activity. Subsequent rational design and synthesis of this hit compound led to improved antimicrobial activity against Streptococcus pneumoniae, with the minimum inhibitory concentration (MIC) reduced from 128 to 1 µg/mL. Additional characterization of the antimicrobial activity, inhibitory activity against RNAP-NusG interaction, and cell-based transcription and fluorescent assays of the optimized compounds demonstrated their potential for further lead optimization.


Assuntos
Antibacterianos , RNA Polimerases Dirigidas por DNA , Testes de Sensibilidade Microbiana , Streptococcus pneumoniae , RNA Polimerases Dirigidas por DNA/antagonistas & inibidores , RNA Polimerases Dirigidas por DNA/metabolismo , Streptococcus pneumoniae/efeitos dos fármacos , Streptococcus pneumoniae/enzimologia , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/síntese química , Descoberta de Drogas , Ligação Proteica , Relação Estrutura-Atividade , Proteínas de Bactérias/antagonistas & inibidores , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/química , Escherichia coli/efeitos dos fármacos , Fatores de Elongação da Transcrição/metabolismo , Fatores de Elongação da Transcrição/antagonistas & inibidores
10.
Front Pharmacol ; 15: 1398953, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39135788

RESUMO

Introduction: Sodium zirconium cyclosilicate (SZC) is a nonabsorbed cation-exchanger approved in China for the treatment of hyperkalemia [HK; serum potassium (sK+) levels >5.0 mmol/L]. This is the first real-world study aimed to assess the effectiveness, safety, and treatment patterns of SZC in Chinese patients with HK. Here we present the results of the first interim analysis. Methods: This multicenter, prospective, cohort study included patients aged ≥18 years with documented HK within 1-year before study enrollment day. These patients were followed up for 6 months from the enrollment day after initiating SZC treatment. The treatment was categorized into correction phase (FAS-P1) and maintenance phase (FAS-P2 new and ongoing users). Subgroup analysis was performed in patients on hemodialysis (FAS-H). The primary objective was evaluation of safety profile of SZC; secondary objectives included assessment of treatment patterns of SZC and its effectiveness. Results: Of 421 screened patients, 193, 354, and 162 patients were enrolled in the FAS-P1, FAS-P2, and FAS-H groups, respectively. sK+ levels were reduced significantly from 5.9 mmol/L to 5.0 mmol/L after the correction phase. For the maintenance phase, the mean sK+ levels were maintained at 5.2 mmol/L and 5.0 mmol/L in the FAS-P2 new and ongoing user, respectively, and 5.3 mmol/L in the FAS-H subgroup. A considerable proportion of patients showed normokalemia after 48 h of SZC treatment (FAS-P1:51.3%) which was maintained up to 6 months in the maintenance phase (FAS-P2:44%). SZC was well-tolerated. Conclusion: SZC was effective and safe for the treatment of HK in real-world clinical practice in China.

11.
Ecotoxicol Environ Saf ; 284: 116915, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39178764

RESUMO

Fine particulate matter (PM2.5) may disrupt women's reproductive hormones, posing potential reproductive risks. However, the exact compositions of PM2.5 responsible for these effects remain unclear. Our investigation explored the long-term impacts of PM2.5 constituents on reproductive hormones, based on a large longitudinal assisted reproductive cohort study in Anhui, China. We included 24,396 reproductive hormone samples from 19,845 women attending assisted reproductive technologies (ART) between 2014 and 2020. Using high-resolution gridded data (1-km resolution), we calculated the residence-specified PM2.5 constituents during the year before the month of hormone testing. Relationships between PM2.5 constituents [organic matter (OM), chloride (Cl-), sulfate (SO42-), ammonium (NH4+), black carbon, and nitrate] and reproductive hormones were investigated using the linear mixed model with subject-specific intercepts. The constituent-proportion model and the constituent-residual model were also constructed. Additionally, cubic spline analysis was used to examine the potential non-linear exposure-response relationship. We found that per interquartile range (IQR) increment in OM was associated with a 5.31 % (3.74 %, 6.89 %) increase in estradiol, and per IQR increment in Cl- and NH4+ were associated with 13.56 % (7.63 %, 19.82 %) and 9.07 % (4.35 %, 14.01 %) increases in luteinizing hormone. Conversely, per IQR increment in OM and Cl- were associated with -7.27 % (-9.34 %, -5.16 %) and -8.52 % (-10.99 %, -5.98 %) decreases in progesterone, and per IQR increment in SO42- was associated with a -9.15 % (-10.31 %, -7.98 %) decrease in testosterone. These associations were held in both proportional and residual models. Moreover, exposure-response curves for estradiol and progesterone with PM2.5 constituents exhibited approximately U-shaped. These results suggested that specific PM2.5 constituents might disrupt reproductive hormone homeostasis in women attending ART, providing new evidence for formulating PM2.5 pollution reduction strategies that could benefit women's reproductive health.


Assuntos
Poluentes Atmosféricos , Estradiol , Material Particulado , Técnicas de Reprodução Assistida , Material Particulado/análise , Feminino , Humanos , Estudos Longitudinais , Adulto , China , Poluentes Atmosféricos/análise , Homeostase/efeitos dos fármacos , Progesterona , Exposição Ambiental , Hormônio Luteinizante
12.
Clin Cosmet Investig Dermatol ; 17: 1603-1612, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38984321

RESUMO

Alopecia is considered a widespread yet troubling health issue, with limited treatment options. As membranous structures derived from cells carrying proteins, nucleic acids and lipids, exosomes functionally medicate intercellular communication and alter the responses of recipient cells, resulting in disease restraint or promotion. Exosomes have broad prospects in diagnosis and treatment of diseases. Studies using animal models and at the cellular level have clearly shown that exosomes from several types of cells, including dermal papilla cells and mesenchymal stem cells, have a notable capacity to promote hair growth, suggesting that exosomes may provide a new option to treat alopecia. Here, we present a thorough review of the most recent progress in the application of exosomes to hair growth.

13.
Cell Discov ; 10(1): 75, 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38992047

RESUMO

Conventional macrolide-lincosamide-streptogramin B-ketolide (MLSBK) antibiotics are unable to counter the growing challenge of antibiotic resistance that is conferred by the constitutive methylation of rRNA base A2058 or its G2058 mutation, while the presence of unmodified A2058 is crucial for high selectivity of traditional MLSBK in targeting pathogens over human cells. The absence of effective modes of action reinforces the prevailing belief that constitutively antibiotic-resistant Staphylococcus aureus remains impervious to existing macrolides including telithromycin. Here, we report the design and synthesis of a novel series of macrolides, featuring the strategic fusion of ketolide and quinolone moieties. Our effort led to the discovery of two potent compounds, MCX-219 and MCX-190, demonstrating enhanced antibacterial efficacy against a broad spectrum of formidable pathogens, including A2058-methylated Staphylococcus aureus, Streptococcus pneumoniae, Streptococcus pyogenes, and notably, the clinical Mycoplasma pneumoniae isolates harboring A2058G mutations which are implicated in the recent pneumonia outbreak in China. Mechanistic studies reveal that the modified quinolone moiety of MCX-190 establishes a distinctive secondary binding site within the nascent peptide exit tunnel. Structure-activity relationship analysis underscores the importance of this secondary binding, maintained by a sandwich-like π-π stacking interaction and a water-magnesium bridge, for effective engagement with A2058-methylated ribosomes rather than topoisomerases targeted by quinolone antibiotics. Our findings not only highlight MCX-219 and MCX-190 as promising candidates for next-generation MLSBK antibiotics to combat antibiotic resistance, but also pave the way for the future rational design of the class of MLSBK antibiotics, offering a strategic framework to overcome the challenges posed by escalating antibiotic resistance.

14.
Nat Prod Res ; : 1-4, 2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-39078886

RESUMO

The fruits of Alpinia oxyphylla has been used a famous traditional Chinese medicine. A chemical investigation on the fruits of A. oxyphylla resulted in the isolation of one new acetylated flavanol glucuronide (1) and two known compounds (2-3). Compound 1 displayed a weak inhibitory effect on U251 cells with the IC50 value 128.51 µM while the positive control drug temozolomide exhibited the IC50 value 35.37 µM.

15.
Carbohydr Polym ; 342: 122361, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-39048220

RESUMO

Plasma technology as an advanced oxidation technology, has gained increasing interest to generate numerous chemically reactive species during the plasma discharge process. Such chemically reactive species can trigger a chain of chemical reactions leading to the degradation of macromolecules including polysaccharides. This review primarily summarizes the generation of various chemically reactive species during plasma treatment and their effects on the physico-chemical properties and biological activities of polysaccharides. During plasma treatment, the type of chemically reactive species that play a major role is related to equipment, working gases and types of polysaccharides. The primary chain structure of polysaccharides did not changed much during the plasma treatment, other physico-chemical properties might be changed, such as molecular weight, solubility, hydrophilicity, rheological properties, gel properties, crystallinity, elemental composition, glycosidic bonding, and surface morphology. Additionally, the biological activities of plasma-treated polysaccharides including antibacterial, antioxidant, immunological, antidiabetic activities, and seed germination promotion activities in agriculture could be improved. Therefore, plasma treatment has the potential application in preparing polysaccharides with enhanced biological activities.


Assuntos
Gases em Plasma , Polissacarídeos , Polissacarídeos/química , Polissacarídeos/farmacologia , Gases em Plasma/química , Antioxidantes/química , Antioxidantes/farmacologia , Peso Molecular , Solubilidade , Antibacterianos/química , Antibacterianos/farmacologia , Humanos
16.
Eur J Med Chem ; 276: 116630, 2024 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-38972081

RESUMO

We report here on the structure-activity relationships of hybrids combining 3-descladinosyl clarithromycin with quinolones linked by extended diamine connectors. Several hybrids, exemplified by 23Bc, 23Be, 23Bf, 26Be, and 30Bc, not only restored potency against inducibly resistant pathogens but also exhibited significantly enhanced activities against constitutively resistant strains of Staphylococcus pneumoniae and Staphylococcus pyogenes, which express high-level resistance independent of clarithromycin or erythromycin induction. Additionally, the novel hybrids showed susceptibility against Gram-negative Haemophilus influenzae. Notably, hybrid 23Be demonstrated dual modes of action by inhibiting both protein synthesis and DNA replication in vitro and in vivo. Given these promising characteristics, 23Be emerges as a potential candidate for the treatment of community-acquired bacterial pneumonia.


Assuntos
Antibacterianos , Claritromicina , Desenho de Fármacos , Testes de Sensibilidade Microbiana , Relação Estrutura-Atividade , Claritromicina/farmacologia , Claritromicina/química , Claritromicina/síntese química , Antibacterianos/farmacologia , Antibacterianos/síntese química , Antibacterianos/química , Estrutura Molecular , Diaminas/química , Diaminas/farmacologia , Diaminas/síntese química , Haemophilus influenzae/efeitos dos fármacos , Oximas/química , Oximas/farmacologia , Oximas/síntese química , Relação Dose-Resposta a Droga , Humanos , Animais , Streptococcus pyogenes/efeitos dos fármacos , Farmacorresistência Bacteriana/efeitos dos fármacos
17.
Ecotoxicol Environ Saf ; 282: 116703, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-38986335

RESUMO

3-methyl-4-nitrophenol (PNMC), a degradation product of organophosphorus insecticides and a byproduct of fuel combustion, exerting endocrine-disrupting effects. However, its impact on the meiotic process of oocytes remains unclear. In the present study, we investigated the effects of PNMC on meiotic maturation of mouse oocytes in vitro and related mechanisms. Morphologically, PNMC-exposure affected germinal vesicle breakdown (GVBD) and polar body extrusion (PBE) in mouse oocytes. Proteomic analysis suggested that PNMC-exposure altered oocyte protein expression that are associated with cytoskeleton, mitochondrial function and oxidative stress. Further studies demonstrated that PNMC-exposure disrupted spindle assembly and chromosome alignment, caused sustained activation of spindle assembly checkpoint (SAC), and arrested meiosis in oocytes. Specifically, PNMC-exposure interfered with the function of microtubule organizing centers (MTOCs) by significantly reducing phosphorylated mitogen activated protein kinase (p-MAPK) expression and disrupting the localization of Pericentrin and p-Aurora A, leading to spindle assembly failure. Besides, PNMC-exposure also increased α-tubulin acetylation, decreased microtubule stability. Moreover, PNMC-exposure impaired mitochondrial function, evidenced by abnormal mitochondrial distribution, decreased mitochondrial membrane potential and ATP levels, release of Cytochrome C into the cytoplasm, and elevated ROS levels. As a result, exposure to PNMC caused DNA damage and early apoptosis in oocytes. Fortunately, melatonin was able to promote oocyte maturation by removing the excessive ROS and enhancing mitochondrial function. These results highlight the adverse effects of PNMC on meiotic maturation, and underscore the protective role of melatonin against PNMC-induced damage.


Assuntos
Meiose , Melatonina , Mitocôndrias , Oócitos , Fuso Acromático , Animais , Oócitos/efeitos dos fármacos , Melatonina/farmacologia , Camundongos , Mitocôndrias/efeitos dos fármacos , Feminino , Fuso Acromático/efeitos dos fármacos , Meiose/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Disruptores Endócrinos/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Antioxidantes , Inseticidas/toxicidade
18.
Appl Environ Microbiol ; 90(8): e0071724, 2024 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-39016615

RESUMO

Mechanistic investigations are of paramount importance in elucidating the modes of action of antibiotics and facilitating the discovery of novel drugs. We reported a luciferase-based reporter system using bacterial cells to unveil mechanisms of antimicrobials targeting transcription and translation. The reporter gene Nluc encoding NanoLuciferase (NanoLuc) was integrated into the genome of the Gram-positive model organism, Bacillus subtilis, to generate a reporter strain BS2019. Cellular transcription and translation levels were assessed by quantifying the amount of Nluc mRNA as well as the luminescence catalyzed by the enzyme NanoLuc. We validated this system using three known inhibitors of transcription (rifampicin), translation (chloramphenicol), and cell wall synthesis (ampicillin). The B. subtilis reporter strain BS2019 successfully revealed a decline in Nluc expression by rifampicin and NanoLuc enzyme activity by chloramphenicol, while ampicillin produced no observable effect. The assay was employed to characterize a previously discovered bacterial transcription inhibitor, CUHK242, with known antimicrobial activity against drug-resistant Staphylococcus aureus. Production of Nluc mRNA in our reporter BS2019 was suppressed in the presence of CUHK242, demonstrating the usefulness of the construct, which provides a simple way to study the mechanism of potential antibiotic candidates at early stages of drug discovery. The reporter system can also be modified by adopting different promoters and reporter genes to extend its scope of contribution to other fields of work. IMPORTANCE: Discovering new classes of antibiotics is desperately needed to combat the emergence of multidrug-resistant pathogens. To facilitate the drug discovery process, a simple cell-based assay for mechanistic studies is essential to characterize antimicrobial candidates. In this work, we developed a luciferase-based reporter system to quantify the transcriptional and translational effects of potential compounds and validated our system using two currently marketed drugs. Reporter strains generated in this study provide readily available means for identifying bacterial transcription inhibitors as prospective novel antibacterials. We also provided a series of plasmids for characterizing promoters under various conditions such as stress.


Assuntos
Antibacterianos , Bacillus subtilis , Genes Reporter , Luciferases , Bacillus subtilis/genética , Bacillus subtilis/efeitos dos fármacos , Antibacterianos/farmacologia , Luciferases/genética , Testes de Sensibilidade Microbiana
19.
Nat Chem Biol ; 2024 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-39039256

RESUMO

Growing resistance toward ribosome-targeting macrolide antibiotics has limited their clinical utility and urged the search for superior compounds. Macrolones are synthetic macrolide derivatives with a quinolone side chain, structurally similar to DNA topoisomerase-targeting fluoroquinolones. While macrolones show enhanced activity, their modes of action have remained unknown. Here, we present the first structures of ribosome-bound macrolones, showing that the macrolide part occupies the macrolide-binding site in the ribosomal exit tunnel, whereas the quinolone moiety establishes new interactions with the tunnel. Macrolones efficiently inhibit both the ribosome and DNA topoisomerase in vitro. However, in the cell, they target either the ribosome or DNA gyrase or concurrently both of them. In contrast to macrolide or fluoroquinolone antibiotics alone, dual-targeting macrolones are less prone to select resistant bacteria carrying target-site mutations or to activate inducible macrolide resistance genes. Furthermore, because some macrolones engage Erm-modified ribosomes, they retain activity even against strains with constitutive erm resistance genes.

20.
Adv Sci (Weinh) ; 11(34): e2400205, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38965798

RESUMO

Physical exercise has beneficial effect on anxiety disorders, but the underlying molecular mechanism remains largely unknown. Here, it is demonstrated that physical exercise can downregulate the S-nitrosylation of gephyrin (SNO-gephyrin) in the basolateral amygdala (BLA) to exert anxiolytic effects. It is found that the level of SNO-gephyrin is significantly increased in the BLA of high-anxiety rats and a downregulation of SNO-gephyrin at cysteines 212 and 284 produced anxiolytic effect. Mechanistically, inhibition of SNO-gephyrin by either Cys212 or Cys284 mutations increased the surface expression of GABAAR γ2 and the subsequent GABAergic neurotransmission, exerting anxiolytic effect in male rats. On the other side, overexpression of neuronal nitric oxide synthase in the BLA abolished the anxiolytic-like effects of physical exercise. This study reveals a key role of downregulating SNO-gephyrin in the anxiolytic effects of physical exercise, providing a new explanation for protein post-translational modifications in the brain after exercise.


Assuntos
Ansiedade , Complexo Nuclear Basolateral da Amígdala , Proteínas de Transporte , Regulação para Baixo , Proteínas de Membrana , Condicionamento Físico Animal , Ratos Sprague-Dawley , Animais , Masculino , Ratos , Proteínas de Membrana/metabolismo , Proteínas de Membrana/genética , Ansiedade/metabolismo , Ansiedade/terapia , Complexo Nuclear Basolateral da Amígdala/metabolismo , Proteínas de Transporte/metabolismo , Proteínas de Transporte/genética , Comportamento Animal , Modelos Animais de Doenças
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