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1.
J Ethnopharmacol ; 334: 118568, 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38996949

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Hyssopus cuspidatus Boriss., a classic Uyghur medicine, is used to treat inflammatory lung diseases such as asthma. But the therapeutic effect and mechanism of the volatile oil of Hyssopus cuspidatus Boriss.(HVO) in asthma therapy remain unclear. AIM OF THE STUDY: We aim to characterize the constituents of HVO, investigate the therapeutic effect in OVA-induced allergic asthmatic mice and further explore the molecular mechanism. MATERIALS AND METHODS: In this study, we applied two-dimensional gas chromatography quadrupole time-of-flight mass spectrometry (GC × GC-QTOF MS) to identify the ingredients of HVO. We established OVA-induced asthmatic model to investigate the therapeutic effect of HVO. To further explore the potential molecular pathways, we used network pharmacology approach to perform GO and KEGG pathways enrichment, and then built an ingredient-target-pathway network to identify key molecular pathways. Finally, LPS-induced RAW 264.7 macrophages and OVA-induced asthmatic model were used to validate the potential signaling pathways. RESULTS: GC × GC-QTOF MS analysis revealed the presence of 123 compounds of HVO. The sesquiterpenes and monoterpenes are the main constituents. The in vivo study indicated that HVO suppressed OVA-induced eosinophilic infiltration in lung tissues, inhibited the elevation of IgE, IL-4, IL-5, and IL-13 levels, downregulated the expressions of phosphorylated PI3K, Akt, JNK and P38, and maintained epithelial barrier integrity via reducing the degradation of occludin, Zo-1, Zo-2, and E-cadherin. The in vitro study also revealed an inhibition of NO release and downregulation of phosphorylated PI3K, Akt, JNK and P38 levels. CONCLUSION: HVO alleviates airway inflammation in OVA-induced asthmatic mice by inhibiting PI3K/Akt/JNK/P38 signaling pathway and maintaining airway barrier integrity via reducing the degradation of occludin, Zo-1, Zo-2, and E-cadherin.

2.
Cell Commun Signal ; 22(1): 362, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-39010102

RESUMO

Dihydroorotase (DHOase) is the third enzyme in the six enzymatic reaction steps of the endogenous pyrimidine nucleotide de novo biosynthesis pathway, which is a metabolic pathway conserved in both bacteria and eukaryotes. However, research on the biological function of DHOase in plant pathogenic fungi is very limited. In this study, we identified and named MoPyr4, a homologous protein of Saccharomyces cerevisiae DHOase Ura4, in the rice blast fungus Magnaporthe oryzae and investigated its ability to regulate fungal growth, pathogenicity, and autophagy. Deletion of MoPYR4 led to defects in growth, conidiation, appressorium formation, the transfer and degradation of glycogen and lipid droplets, appressorium turgor accumulation, and invasive hypha expansion in M. oryzae, which eventually resulted in weakened fungal pathogenicity. Long-term replenishment of exogenous uridine-5'-phosphate (UMP) can effectively restore the phenotype and virulence of the ΔMopyr4 mutant. Further study revealed that MoPyr4 also participated in the regulation of the Pmk1-MAPK signaling pathway, co-localized with peroxisomes for the oxidative stress response, and was involved in the regulation of the Osm1-MAPK signaling pathway in response to hyperosmotic stress. In addition, MoPyr4 interacted with MoAtg5, the core protein involved in autophagy, and positively regulated autophagic degradation. Taken together, our results suggested that MoPyr4 for UMP biosynthesis was crucial for the development and pathogenicity of M. oryzae. We also revealed that MoPyr4 played an essential role in the external stress response and pathogenic mechanism through participation in the Pmk1-MAPK signaling pathway, peroxisome-related oxidative stress response mechanism, the Osm1-MAPK signaling pathway and the autophagy pathway.


Assuntos
Autofagia , Proteínas Fúngicas , Oryza , Proteínas Fúngicas/metabolismo , Proteínas Fúngicas/genética , Oryza/microbiologia , Virulência/genética , Peroxissomos/metabolismo , Doenças das Plantas/microbiologia , Ascomicetos/patogenicidade , Ascomicetos/genética , Ascomicetos/enzimologia , Sistema de Sinalização das MAP Quinases , Estresse Oxidativo
3.
J Sci Food Agric ; 2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-38963133

RESUMO

BACKGROUND: Yeast culture (YC) is a product fermented on a specific medium, which is a type of postbiotic of anaerobic solid-state fermentation. Although YC has positive effects on the animal growth and health, it contains a variety of beneficial metabolites as dark matter, which have not been quantified. In the present study, liquid chromatography-tandem mass spectrometry is employed to identify the unknown metabolites. Following their identification, the important chemicals are quantified using HPLC-diode array detection methods. RESULTS: Non-targeted metabolomics studies showed that 670 metabolites in total were identified in YC, of which 23 metabolites significantly increased, including organic acids, amino acids, nucleosides and purines, isoflavones, and other substances. The chemical quantitative analysis showed that the contents of succinic acid, aminobutyric acid, glutamine, purine and daidzein increased by 84.42%, 51.07%, 100%, 68.85% and 4.60%, respectively. CONCLUSION: Therefore, the use of non-targeted metabolomics combined with chemical quantitative analysis to reveal the nutritional and functional substances of YC could help to elucidate the postbiotic mechanism and provide theoretical support for the regulation of the directional accumulation of beneficial metabolites. © 2024 Society of Chemical Industry.

4.
APL Bioeng ; 8(2): 026128, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38948350

RESUMO

Monoclonal antibodies (mAbs) can undergo structural changes due to interaction with oil-water interfaces during storage. Such changes can lead to aggregation, resulting in a loss of therapeutic efficacy. Therefore, understanding the microscopic mechanism controlling mAb adsorption is crucial to developing strategies that can minimize the impact of interfaces on the therapeutic properties of mAbs. In this study, we used MARTINI coarse-grained molecular dynamics simulations to investigate the adsorption of the Fab and Fc domains of the monoclonal antibody COE3 at the oil-water interface. Our aim was to determine the regions on the protein surface that drive mAb adsorption. We also investigate the role of protein concentration on protein orientation and protrusion to the oil phase. While our structural analyses compare favorably with recent neutron reflectivity measurements, we observe some differences. Unlike the monolayer at the interface predicted by neutron reflectivity experiments, our simulations indicate the presence of a secondary diffused layer near the interface. We also find that under certain conditions, protein-oil interaction can lead to a considerable distortion in the protein structure, resulting in enhanced adsorption behavior.

5.
Accid Anal Prev ; 206: 107709, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38986432

RESUMO

Driving behaviors are important cause of expressway crash. In this study, method based on modified time-to-collision (MTTC) to identify risky driving behaviors on an expressway diverge area is proposed, thus investigating the impact of velocity and acceleration features of risky driving behavior. Firstly, MTTC is applied to judge whether the behavior is risky. Then, the relationships between velocity, acceleration and different driving behavior on the expressway diverge area were fit by binary logistic regression models (BLR) with L2 regularization and random forests (RF) models, and the models were interpreted by feature importance plots and partial dependency plots. The results show that the AUC metric of 4 RF models for 4 types of driving behaviors, namely, left lane change, right lane change, acceleration and deceleration, are 0.932, 0.845, 0.846 and 0.860 separately. The interpretation of models demonstrates that velocity and absolute value of acceleration greatly affect the risk of the driving behaviors. Different driving behaviors with a certain acceleration have a range of safety speed range. The range will get narrower with the growth of maximum absolute value of acceleration rate, and will be nearly non-exist when the acceleration is over 5 m/s2. In conclusion, this study provided a methodology to measure the risk of driving behaviors and establish a model to recognize of risky driving behaviors. The results can lay the foundation for making countermeasures to prevent risky driving behaviors by managing the vehicle speed.

6.
J Transl Med ; 22(1): 644, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38982507

RESUMO

BACKGROUND: Genetic disorders often manifest as abnormal fetal or childhood development. Copy number variations (CNVs) represent a significant genetic mechanism underlying such disorders. Despite their importance, the effectiveness of clinical exome sequencing (CES) in detecting CNVs, particularly small ones, remains incompletely understood. We aimed to evaluate the detection of both large and small CNVs using CES in a substantial clinical cohort, including parent-offspring trios and proband only analysis. METHODS: We conducted a retrospective analysis of CES data from 2428 families, collected from 2018 to 2021. Detected CNV were categorized as large or small, and various validation techniques including chromosome microarray (CMA), Multiplex ligation-dependent probe amplification assay (MLPA), and/or PCR-based methods, were employed for cross-validation. RESULTS: Our CNV discovery pipeline identified 171 CNV events in 154 cases, resulting in an overall detection rate of 6.3%. Validation was performed on 113 CNVs from 103 cases to assess CES reliability. The overall concordance rate between CES and other validation methods was 88.49% (100/113). Specifically, CES demonstrated complete consistency in detecting large CNV. However, for small CNVs, consistency rates were 81.08% (30/37) for deletions and 73.91% (17/23) for duplications. CONCLUSION: CES demonstrated high sensitivity and reliability in CNV detection. It emerges as an economical and dependable option for the clinical CNV detection in cases of developmental abnormalities, especially fetal structural abnormalities.


Assuntos
Variações do Número de Cópias de DNA , Sequenciamento do Exoma , Doenças Genéticas Inatas , Humanos , Variações do Número de Cópias de DNA/genética , Doenças Genéticas Inatas/diagnóstico , Doenças Genéticas Inatas/genética , Reprodutibilidade dos Testes , Feminino , Valor Preditivo dos Testes , Masculino , Estudos Retrospectivos
7.
J Gastrointest Oncol ; 15(3): 1122-1140, 2024 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-38989427

RESUMO

Background: In inoperable hepatocellular carcinoma (HCC), chemotherapy is a common treatment strategy. However, there is a lack of reliable methods to predict the prognosis of patients with inoperable HCC after chemotherapy. Therefore, the aim of this study was to identify the clinical characteristics of patients with inoperable HCC and to establish and validate nomogram models for predicting the survival outcomes in this patient group following chemotherapy. Methods: The data of patients diagnosed with HCC from the Surveillance, Epidemiology, and End Results (SEER) database were retrospectively collected. Logistic regression analyses were used to identify potential factors for inoperability in patients with HCC. Kaplan-Meier analyses were applied to evaluate the impact of chemotherapy on prognosis. Additionally, Cox regression analyses were performed to identify the potential risk factors associated with overall survival (OS) and cancer-specific survival (CSS) in patients with inoperable HCC treated with chemotherapy. Finally, we constructed prognostic nomograms for predicting the 1- and 3-year survival probabilities. Results: A total of 3,519 operable patients with HCC and 4,656 patients with inoperable HCC were ultimately included in this study. Logistic regression analyses revealed a significant association between patient age, gender, race, tumor, node, metastasis (TNM) stage, tumor size, pretreatment alpha fetoprotein (AFP) levels, and marital status with inoperability. Moreover, Kaplan-Meier analyses revealed a significant improvement in both OS and CSS with the administration of chemotherapy. Moreover, 1,456 patients with inoperable HCC were enrolled in the training group and 631 patients with inoperable HCC were enrolled in the validation group to develop and validate the prognostic models. Cox regression models indicated that TNM stage, tumor size, and pretreatment AFP were independent risk factors for predicting OS and CSS in patients with inoperable HCC receiving chemotherapy. These factors were subsequently integrated into the predictive nomograms. Conclusions: We preliminarily developed survival models with strong predictive capabilities for estimating survival probabilities in patients with HCC following chemotherapy. These models hold potential for clinical application and warrant further exploration through additional studies.

8.
Nature ; 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38987597

RESUMO

Glutamate is traditionally viewed as the first messenger to activate NMDAR (N-methyl-D-aspartate receptor)-dependent cell death pathways in stroke1,2, but unsuccessful clinical trials with NMDAR antagonists implicate the engagement of other mechanisms3-7. Here we show that glutamate and its structural analogues, including NMDAR antagonist L-AP5 (also known as APV), robustly potentiate currents mediated by acid-sensing ion channels (ASICs) associated with acidosis-induced neurotoxicity in stroke4. Glutamate increases the affinity of ASICs for protons and their open probability, aggravating ischaemic neurotoxicity in both in vitro and in vivo models. Site-directed mutagenesis, structure-based modelling and functional assays reveal a bona fide glutamate-binding cavity in the extracellular domain of ASIC1a. Computational drug screening identified a small molecule, LK-2, that binds to this cavity and abolishes glutamate-dependent potentiation of ASIC currents but spares NMDARs. LK-2 reduces the infarct volume and improves sensorimotor recovery in a mouse model of ischaemic stroke, reminiscent of that seen in mice with Asic1a knockout or knockout of other cation channels4-7. We conclude that glutamate functions as a positive allosteric modulator for ASICs to exacerbate neurotoxicity, and preferential targeting of the glutamate-binding site on ASICs over that on NMDARs may be strategized for developing stroke therapeutics lacking the psychotic side effects of NMDAR antagonists.

9.
Clinics (Sao Paulo) ; 79: 100441, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38976936

RESUMO

OBJECTIVE: This study aimed to identify differentially expressed microRNAs (miRNAs) in exosomes derived from the blood plasma of Rheumatoid Arthritis (RA) patients and explore their clinical significance and biological roles. METHODS: Illumina high-throughput sequencing was employed to measure miRNA expression levels in plasma exosomes, followed by validation using qRT-PCR. The correlation between exosomal miRNAs and disease activity was systematically analyzed. Additionally, the pathogenic effects of RA exosomes were investigated through bioinformatics analysis and in vitro experiments. RESULTS: Significantly reduced levels of exosomal miR-144-3p and miR-30b-5p were observed in RA patients, which were negatively correlated with DAS28 scores and anti-CCP antibody levels. ROC curve analysis showed that miR-144-3p and miR-30b-5p in plasma exosomes could effectively distinguish RA patients from healthy controls, with AUC values of 0.725 and 0.773, respectively. Combining bioinformatics analysis and in vitro experiments, it was demonstrated that plasma exosomes contribute to ongoing autoantibody production in RA by promoting B-cell differentiation and antibody production. CONCLUSION: The present study indicates that plasma exosomes from RA patients may be potentially pathogenic. Exosomal miR-144-3p and miR-30b-5p exhibit significant decreases in RA patients and are associated with disease activity, suggesting their potential as valuable biomarkers for RA.


Assuntos
Artrite Reumatoide , Linfócitos B , Exossomos , MicroRNAs , Humanos , Artrite Reumatoide/sangue , Artrite Reumatoide/genética , Artrite Reumatoide/imunologia , MicroRNAs/sangue , Feminino , Masculino , Pessoa de Meia-Idade , Linfócitos B/imunologia , Estudos de Casos e Controles , Adulto , Biomarcadores/sangue , Curva ROC , Reação em Cadeia da Polimerase em Tempo Real
10.
Synth Syst Biotechnol ; 9(4): 784-792, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-39021361

RESUMO

The diterpene ent-copalol is an important precursor to the synthesis of andrographolide and is found only in green chiretta (Andrographis paniculata). De novo biosynthesis of ent-copalol has not been reported, because the catalytic activity of ent-copalyl diphosphate synthase (CPS) is very low in microorganisms. In order to achieve the biosynthesis of ent-copalol, Saccharomyces cerevisiae was selected as the chassis strain, because its endogenous mevalonate pathway and dephosphorylases could provide natural promotion for the synthesis of ent-copalol. The strain capable of synthesizing diterpene geranylgeranyl pyrophosphate was constructed by strengthening the mevalonate pathway genes and weakening the competing pathway. Five full-length ApCPSs were screened by transcriptome sequencing of A. paniculata and ApCPS2 had the best activity and produced ent-CPP exclusively. The peak area of ent-copalol was increased after the ApCPS2 saturation mutation and its configuration was determined by NMR and ESI-MS detection. By appropriately optimizing acetyl-CoA supply and fusion-expressing key enzymes, 35.6 mg/L ent-copalol was generated. In this study, de novo biosynthesis and identification of ent-copalol were achieved and the highest titer ever reported. It provides a platform strain for the further pathway analysis of andrographolide and derivatives and provides a reference for the synthesis of other pharmaceutical intermediates.

11.
Regen Biomater ; 11: rbae070, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39022124

RESUMO

A hybrid material possessing both componential and structural imitation of bone tissue is the preferable composites for bone defect repair. Inspired by the microarchitecture of native bone, this work synthesized in vitro a functional mineralized collagen fibril (MCF) material by utilizing the method of in situ co-precipitation, which was designed to proceed in the presence of Astragalus polysaccharide (APS), thus achieving APS load within the biomineralized collagen-Astragalus polysaccharide (MCAPS) fibrils. Transmission electron microscope (TEM), selected area electron diffraction (SAED) and scanning electronic microscopy (SEM) identified the details of the intrafibrillar mineralization of the MCAPS fibrils, almost mimicking the secondary level of bone tissue microstructure. A relatively uniform and continuous mineral layer formed on and within all collagen fibrils and the mineral phase was identified as typical weak-crystalline hydroxyapatite (HA) with a Ca/P ratio of about 1.53. The proliferation of bone marrow-derived mesenchymal stem cells (BMSC) and mouse embryo osteoblast precursor cells (MC3T3-E1) obtained a significant promotion by MCAPS. As for the osteogenic properties of MCAPS, a distinct increase in the alkaline phosphatase (ALP) activity and the number of calcium nodules (CN) in BMSC and MC3T3-E1 was detected. The up-regulation of three osteogenic-related genes of RUNX-2, BMP-2 and OCN were confirmed via reverse transcription-quantitative polymerase chain reaction (RT-qPCR) to further verify the osteogenic performance promotion of MCAPS. A period of 14 days of culture demonstrated that MCAPS-L exhibited a preferable efficacy in enhancing ALP activity and CN quantity, as well as in promoting the expression of osteogenic-related genes over MCAPS-M and MCAPS-H, indicating that a lower dose of APS within the material of MCAPS is more appropriate for its osteogenesis promotion properties.

12.
Opt Express ; 32(10): 16970-16982, 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38858891

RESUMO

Laser-induced plasma micromachining (LIPMM) is an advanced technology that utilizes the plasma generated from laser breakdown to remove material, thereby facilitating the fabrication of microstructures. This paper explores the use of LIPMM on 304 stainless steel surfaces parallel to the laser beam in different solutions, focusing on the impact of the liquid environment on the machining process. It presents a theoretical analysis of the material removal mechanisms unique to this orientation and experimentally investigates how water, a salt solution, and ethanol affect plasma shockwave characteristics. Notably, the plasma shockwave in the salt solution demonstrates the most significant peak pressure and energy, enhancing the micromachining efficiency. These findings suggest that varying the liquid environment can significantly influence LIPMM's effectiveness, offering potential improvements in precision and control. This study broadens the understanding of LIPMM applications, especially in orientations not commonly explored, and opens new possibilities for advanced micromachining techniques in various industrial applications.

13.
J Colloid Interface Sci ; 674: 279-288, 2024 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-38936084

RESUMO

Rational design of coordination environment of Fe-based metal-organic frameworks (Fe-MOFs) is still a challenge in achieving enhanced catalytic activity for Fenten-like advanced oxidation process. Here in, novel porous Fe-MOFs with modulated O-Fe-N coordination was developed by configurating amino terephthalic acid (H2ATA) and pyrazine-dicarboxylic acid (PzDC) (Fe-ATA/PzDC-7:3). PzDC ligands introduce pyridine-N sites to form O-Fe-N coordination with lower binding energy, which affect the local electronic environment of Fe-clusters in Fe-ATA, thus decreased its interfacial H2O2 activation barrier. O-Fe-N coordination also accelerate Fe(II)/Fe(III) cycling of Fe-clusters by triggering the reactive oxidant species mediated Fe(III) reduction. As such, Fe-ATA/PzDC-7:3/H2O2 system exhibited excellent degradation performance for typical antibiotic sulfamethoxazole (SMX), in which the steady-state concentration of hydroxyl radical (OH) was 1.6 times higher than that of unregulated Fe-ATA. Overall, this study highlights the role of O-Fe-N coordination and the electronic environment of Fe-clusters on regulating Fenton-like catalytic performance, and provides a platform for precise engineering of Fe-MOFs.

14.
Plant Physiol Biochem ; 212: 108778, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38838570

RESUMO

The albino tea cultivar is one of the most important germplasms for key gene mining and high-quality tea producing. In order to elucidate the chlorophyll-deficient mechanism of albino cultivar 'Huangjinya' and its offspring, color difference, photosynthetic pigments and the relevant genes' expression of the tender shoots were comprehensively investigated in this study. Among the tested 16 offspring, 5 exhibited albino phenotype in spring and autumn, 3 showed albino phenotype in spring but normal green in autumn, while the rests were all normal green. The shoot of albino offspring had significantly higher lightness and/or yellowness than that of green ones, and possessed dramatically lower photosynthetic pigments and chlorophyll precursor protochlorophyllide (Pchlide), as well as higher chlorophyll a/chlorophyll b but lower chlorophylls/carotenoids in comparison with green ones. Among the tested genes involved in chlorophyll and carotenoid metabolism pathways, expression of the magnesium protoporphyrin IX monomethyl ester cyclase (CRD), 3,8-divinyl chlorophyllide 8-vinyl reductase (DVR), 5-aminolevulinate dehydratase 1 (HEMB1), 1-deoxy-D-xylulose 5-phosphate synthase 1 (DXS1) and 4-hydroxy-3-methylbut-2-enyl diphosphate reductase (ISPH) was remarkably down-regulated in shoots of the albino offspring. Color difference indices of the offspring were significantly correlated with the levels of photosynthetic pigments and Pchlide, and low level of chlorophylls in shoot of albino offspring was mainly due to conversion obstacle from magnesium protoporphyrin Ⅸ (Mg-Proto IX) to Pchlide which might be attributed to down-regulatory expression of CRD and DVR.


Assuntos
Clorofila , Fenótipo , Protoclorifilida , Protoporfirinas , Clorofila/metabolismo , Protoclorifilida/metabolismo , Protoporfirinas/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Fotossíntese
15.
Artigo em Inglês | MEDLINE | ID: mdl-38862422

RESUMO

The monkeypox virus (mpox virus, MPXV) epidemic in 2022 has posed a significant public health risk. Yet, the evolutionary principles of MPXV remain largely unknown. Here, we examined the evolutionary patterns of protein sequences and codon usage in MPXV. We first demonstrated the signal of positive selection in OPG027, specifically in the Clade I lineage of MPXV. Subsequently, we discovered accelerated protein sequence evolution over time in the variants responsible for the 2022 outbreak. Furthermore, we showed strong epistasis between amino acid substitutions located in different genes. The codon adaptation index (CAI) analysis revealed that MPXV genes tended to use more non-preferred codons compared to human genes, and the CAI decreased over time and diverged between clades, with Clade I > IIa and IIb-A > IIb-B. While the decrease in fatality rate among the three groups aligned with the CAI pattern, it remains unclear whether this correlation was coincidental or if the deoptimization of codon usage in MPXV led to a reduction in fatality rates. This study sheds new light on the mechanisms that govern the evolution of MPXV in human populations.


Assuntos
Uso do Códon , Evolução Molecular , Monkeypox virus , Humanos , Monkeypox virus/genética , Proteínas Virais/genética , Filogenia , Seleção Genética , Códon/genética , Sequência de Aminoácidos/genética , Substituição de Aminoácidos/genética , Mpox/virologia , Mpox/genética
16.
J Colloid Interface Sci ; 672: 209-223, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-38838629

RESUMO

Multidrug resistance (MDR) is a rising threat to global health because the number of essential antibiotics used for treating MDR infections is increasingly compromised. In this work we report a group of new amphiphilic peptides (AMPs) derived from the well-studied G3 (G(IIKK)3I-NH2) to fight infections from Gram-positive bacteria including susceptible Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA), focusing on membrane interactions. Time-dependent killing experiments revealed that substitutions of II by WW (GWK), II by FF (GFK) and KK by RR (GIR) resulted in improved bactericidal efficiencies compared to G3 (GIK) on both S. aureus and MRSA, with the order of GWK > GIR > GFK > GIK. Electronic microscopy imaging revealed structural disruptions of AMP binding to bacterial cell walls. Fluorescence assays including AMP binding to anionic lipoteichoic acids (LTA) in cell-free and cell systems indicated concentration and time-dependent membrane destabilization associated with bacterial killing. Furthermore, AMP's binding to anionic plasma membrane via similar fluorescence assays revealed a different extent of membrane depolarization and leakage. These observations were supported by the penetration of AMPs into the LTA barrier and the subsequent structural compromise to the cytoplasmic membrane as revealed from SANS (small angle neutron scattering). Both experiments and molecular dynamics (MD) simulations revealed that GWK and GIR could make the membrane more rigid but less effective in diffusive efficiency than GIK and GFK through forming intramembrane peptide nanoaggregates associated with hydrophobic mismatch and formation of fluidic and rigid patches. The reported peptide-aggregate-induced phase-separation emerged as a crucial factor in accelerated membrane disintegration and fast bacterial killing. This work has demonstrated the importance of membrane interactions to the development of more effective AMPs and the relevance of the approaches as reported in assisting this area of research.


Assuntos
Antibacterianos , Staphylococcus aureus Resistente à Meticilina , Testes de Sensibilidade Microbiana , Antibacterianos/farmacologia , Antibacterianos/química , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/farmacologia , Cátions/química , Tensoativos/química , Tensoativos/farmacologia , Simulação de Dinâmica Molecular
17.
Nat Commun ; 15(1): 5288, 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38902277

RESUMO

Psoriasis is an immune-mediated skin disease associated with neurogenic inflammation, but the underlying molecular mechanism remains unclear. We demonstrate here that acid-sensing ion channel 3 (ASIC3) exacerbates psoriatic inflammation through a sensory neurogenic pathway. Global or nociceptor-specific Asic3 knockout (KO) in female mice alleviates imiquimod-induced psoriatic acanthosis and type 17 inflammation to the same extent as nociceptor ablation. However, ASIC3 is dispensable for IL-23-induced psoriatic inflammation that bypasses the need for nociceptors. Mechanistically, ASIC3 activation induces the activity-dependent release of calcitonin gene-related peptide (CGRP) from sensory neurons to promote neurogenic inflammation. Botulinum neurotoxin A and CGRP antagonists prevent sensory neuron-mediated exacerbation of psoriatic inflammation to similar extents as Asic3 KO. In contrast, replenishing CGRP in the skin of Asic3 KO mice restores the inflammatory response. These findings establish sensory ASIC3 as a critical constituent in psoriatic inflammation, and a promising target for neurogenic inflammation management.


Assuntos
Canais Iônicos Sensíveis a Ácido , Peptídeo Relacionado com Gene de Calcitonina , Camundongos Knockout , Psoríase , Células Receptoras Sensoriais , Animais , Canais Iônicos Sensíveis a Ácido/metabolismo , Canais Iônicos Sensíveis a Ácido/genética , Feminino , Psoríase/metabolismo , Psoríase/patologia , Psoríase/genética , Psoríase/induzido quimicamente , Camundongos , Peptídeo Relacionado com Gene de Calcitonina/metabolismo , Peptídeo Relacionado com Gene de Calcitonina/genética , Células Receptoras Sensoriais/metabolismo , Pele/metabolismo , Pele/patologia , Imiquimode , Camundongos Endogâmicos C57BL , Modelos Animais de Doenças , Inflamação/metabolismo , Inflamação Neurogênica/metabolismo , Humanos , Nociceptores/metabolismo , Interleucina-23/metabolismo , Interleucina-23/genética
19.
Hum Vaccin Immunother ; 20(1): 2358570, 2024 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-38853516

RESUMO

Among all natural and synthetic toxins, botulinum neurotoxins (BoNTs), produced by Clostridium botulinum in an anaerobic environment, are the most toxic polymer proteins. Currently, the most effective modalities for botulism prevention and treatment are vaccination and antitoxin use, respectively. However, these modalities are associated with long response time for active immunization, side effects, and donor limitations. As such, the development of more promising botulism prevention and treatment modalities is warranted. Here, we designed an mRNA encoding B9-hFc - a heavy-chain antibody fused to VHH and human Fc that can neutralize BoNT serotype B (BoNT/B) effectively - and assessed its expression in vitro and in vivo. The results confirmed that our mRNA demonstrates good expression in vitro and in vivo. Moreover, a single mRNA lipid nanoparticle injection effectively prevents BoNT/B intoxication in vivo, with effects comparable to those of protein antibodies. In conclusion, we explored and clarified whether mRNA drugs encoding neutralizing antibodies prevent BoNT/B intoxication. Our results provide an efficient strategy for further research on the prevention and treatment of intoxication by botulinum toxin.


Assuntos
Anticorpos Neutralizantes , Toxinas Botulínicas Tipo A , Botulismo , RNA Mensageiro , Anticorpos Neutralizantes/imunologia , Animais , Botulismo/prevenção & controle , Botulismo/imunologia , Toxinas Botulínicas Tipo A/imunologia , RNA Mensageiro/genética , RNA Mensageiro/imunologia , Camundongos , Humanos , Feminino , Nanopartículas , Camundongos Endogâmicos BALB C , Anticorpos Antibacterianos/imunologia , Vacinas Sintéticas/imunologia , Vacinas Sintéticas/administração & dosagem , Lipossomos
20.
Nat Commun ; 15(1): 5060, 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38871686

RESUMO

Arctic Amplification (AA), the amplified surface warming in the Arctic relative to the globe, is a salient feature of climate change. While the basic physical picture of AA has been depicted, how its degree is determined has not been clearly understood. Here, by deciphering atmospheric heat transport (AHT), we build a two-box energy-balance model of AA and derive that the degree of AA is a simple nonlinear function of the Arctic and global feedbacks, the meridional heterogeneity in radiative forcing, and the partial sensitivities of AHT to global mean and meridional gradient of warming. The formula captures the varying AA in climate models and attributes the spread to models' feedback parameters and AHT physics. The formula clearly illustrates how essential physics mutually determine the degree of AA and limits its range within 1.5-3.5. Our results articulate AHT as both forcing and feedback to AA, highlight its fundamental role in forming a baseline AA that exists even with uniform feedbacks, and underscore its partial sensitivities instead of its total change as key parameters of AA. The lapse-rate feedback has been widely recognized as a major contributor to AA but its effect is fully offset by the water-vapor feedback.

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