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1.
Proc Natl Acad Sci U S A ; 121(6): e2304619121, 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38289962

RESUMO

Resistance to neoadjuvant chemotherapy leads to poor prognosis of locally advanced rectal cancer (LARC), representing an unmet clinical need that demands further exploration of therapeutic strategies to improve clinical outcomes. Here, we identified a noncanonical role of RB1 for modulating chromatin activity that contributes to oxaliplatin resistance in colorectal cancer (CRC). We demonstrate that oxaliplatin induces RB1 phosphorylation, which is associated with the resistance to neoadjuvant oxaliplatin-based chemotherapy in LARC. Inhibition of RB1 phosphorylation by CDK4/6 inhibitor results in vulnerability to oxaliplatin in both intrinsic and acquired chemoresistant CRC. Mechanistically, we show that RB1 modulates chromatin activity through the TEAD4/HDAC1 complex to epigenetically suppress the expression of DNA repair genes. Antagonizing RB1 phosphorylation through CDK4/6 inhibition enforces RB1/TEAD4/HDAC1 repressor activity, leading to DNA repair defects, thus sensitizing oxaliplatin treatment in LARC. Our study identifies a RB1 function in regulating chromatin activity through TEAD4/HDAC1. It also provides the combination of CDK4/6 inhibitor with oxaliplatin as a potential synthetic lethality strategy to mitigate oxaliplatin resistance in LARC, whereby phosphorylated RB1/TEAD4 can serve as potential biomarkers to guide the patient stratification.


Assuntos
Terapia Neoadjuvante , Neoplasias Retais , Humanos , Oxaliplatina/farmacologia , Terapia Neoadjuvante/métodos , Neoplasias Retais/tratamento farmacológico , Neoplasias Retais/genética , Quimiorradioterapia/métodos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Cromatina , Resultado do Tratamento , Fatores de Transcrição de Domínio TEA , Ubiquitina-Proteína Ligases , Proteínas de Ligação a Retinoblastoma
2.
Proc Natl Acad Sci U S A ; 120(25): e2301885120, 2023 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-37314934

RESUMO

The controllability and targeting of nanoparticles (NPs) offer solutions for precise and sustainable agriculture. However, the development potential of nanoenabled agriculture remains unknown. Here, we build an NP-plant database containing 1,174 datasets and predict (R2 higher than 0.8 for 13 random forest models) the response and uptake/transport of various NPs by plants using a machine learning approach. Multiway feature importance analysis quantitatively shows that plant responses are driven by the total NP exposure dose and duration and plant age at exposure, as well as the NP size and zeta potential. Feature interaction and covariance analysis further improve the interpretability of the model and reveal hidden interaction factors (e.g., NP size and zeta potential). Integration of the model, laboratory, and field data suggests that Fe2O3 NP application may inhibit bean growth in Europe due to low night temperatures. In contrast, the risks of oxidative stress are low in Africa because of high night temperatures. According to the prediction, Africa is a suitable area for nanoenabled agriculture. The regional differences and temperature changes make nanoenabled agriculture complicated. In the future, the temperature increase may reduce the oxidative stress in African bean and European maize induced by NPs. This study projects the development potential of nanoenabled agriculture using machine learning, although many more field studies are needed to address the differences at the country and continental scales.


Assuntos
Agricultura , Aprendizado de Máquina , Nanopartículas , África
3.
Nano Lett ; 24(7): 2181-2187, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38340079

RESUMO

Recently discovered as an intrinsic antiferromagnetic topological insulator, MnBi2Te4 has attracted tremendous research interest, as it provides an ideal platform to explore the interplay between topological and magnetic orders. MnBi2Te4 displays distinct exotic topological phases that are inextricably linked to the different magnetic structures of the material. In this study, we conducted electrical transport measurements and systematically investigated the anomalous Hall response of epitaxial MnBi2Te4 films when subjected to an external magnetic field sweep, revealing the different magnetic structures stemming from the interplay of applied fields and the material's intrinsic antiferromagnetic (AFM) ordering. Our results demonstrate that the nonsquare anomalous Hall loop is a consequence of the distinct reversal processes within individual septuple layers. These findings shed light on the intricate magnetic structures in MnBi2Te4 and related materials, offering insights into understanding their transport properties and facilitating the implementation of AFM topological electronics.

4.
Chemistry ; : e202400985, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38932665

RESUMO

Bioreduction of spin labels and polarizing agents (generally stable radicals) has been an obstacle limiting the in-cell applications of pulsed electron paramagnetic resonance (EPR) spectroscopy and dynamic nuclear polarization (DNP). In this work, we have demonstrated that two semiquinone methide radicals (OXQM• and CTQM•) can be easily produced from the trityl-based quinone methides (OXQM and CTQM) via reduction by various reducing agents including biothiols and ascorbate under anaerobic conditions. Both radicals have relatively low pKa's and exhibit EPR single line signals at physiological pH. Moreover, the bioreduction of OXQM in three cell lysates enables quantitative generation of OXQM• which was most likely mediated by flavoenzymes. Importantly, the resulting OXQM• exhibited extremely high stability in the E.coli lysate under anaerobic conditions with 76- and 14.3-fold slower decay kinetics as compared to the trityl OX063 and a gem-diethyl pyrrolidine nitroxide. Intracellular delivery of OXQM into HeLa cells was also achieved by covalent conjugation with a cell-permeable peptide as evidenced by the stable intracellular EPR signal from the OXQM• moiety. Owing to extremely high resistance of OXQM• towards bioreduction, OXQM and its derivatives show great application potential in in-cell EPR and in-cell DNP studies for various cells which can endure short-term anoxic treatments.

5.
Virol J ; 21(1): 13, 2024 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-38191416

RESUMO

BACKGROUND: In December 2022, Chongqing experienced a significant surge in coronavirus disease 2019 (COVID-19) epidemic after adjusting control measures in China. Given the widespread immunization of the population with the BA.5 variant, it is crucial to actively monitor severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant evolution in Chongqing's Yubei district. METHODS: In this retrospective study based on whole genome sequencing, we collected oropharyngeal and nasal swab of native COVID-19 cases from Yubei district between January to May 2023, along with imported cases from January 2022 to January 2023. Through second-generation sequencing, we generated a total of 578 genomes. RESULTS: Phylogenetic analyses revealed these genomes belong to 47 SARS-CoV-2 Pango lineages. BA.5.2.48 was dominant from January to April 2023, rapidly replaced by XBB* variants from April to May 2023. Bayesian Skyline Plot reconstructions indicated a higher evolutionary rate (6.973 × 10-4 subs/site/year) for the XBB.1.5* lineage compared to others. The mean time to the most recent common ancestor (tMRCA) of BA.5.2.48* closely matched BA.2.75* (May 27, 2022). Using multinomial logistic regression, we estimated growth advantages, with XBB.1.9.1 showing the highest growth advantage (1.2, 95% HPI:1.1-1.2), followed by lineage FR.1 (1.1, 95% HPI:1.1-1.2). CONCLUSIONS: Our monitoring reveals the rapid replacement of the previously prevalent BA.5.2.48 variant by XBB and its sub-variants, underscoring the ineffectiveness of herd immunity and breakthrough BA.5 infections against XBB variants. Given the ongoing evolutionary pressure, sustaining a SARS-CoV-2 genomic surveillance program is imperative.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , Teorema de Bayes , Filogenia , Estudos Retrospectivos , COVID-19/epidemiologia , Genômica , China/epidemiologia
6.
Cell Commun Signal ; 22(1): 162, 2024 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-38448976

RESUMO

Microglia/macrophages are major contributors to neuroinflammation in the central nervous system (CNS) injury and exhibit either pro- or anti-inflammatory phenotypes in response to specific microenvironmental signals. Our latest in vivo and in vitro studies demonstrated that curcumin-treated olfactory ensheathing cells (aOECs) can effectively enhance neural survival and axonal outgrowth, and transplantation of aOECs improves the neurological outcome after spinal cord injury (SCI). The therapeutic effect is largely attributed to aOEC anti-inflammatory activity through the modulation of microglial polarization from the M1 to M2 phenotype. However, very little is known about what viable molecules from aOECs are actively responsible for the switch of M1 to M2 microglial phenotypes and the underlying mechanisms of microglial polarization. Herein, we show that Interleukin-4 (IL-4) plays a leading role in triggering the M1 to M2 microglial phenotype, appreciably decreasing the levels of M1 markers IL­1ß, IL­6, tumour necrosis factor-alpha (TNF-α) and inducible nitric oxide synthase (iNOS) and elevating the levels of M2 markers Arg-1, TGF-ß, IL-10, and CD206. Strikingly, blockade of IL-4 signaling by siRNA and a neutralizing antibody in aOEC medium reverses the transition of M1 to M2, and the activated microglia stimulated with the aOEC medium lacking IL-4 significantly decreases neuronal survival and neurite outgrowth. In addition, transplantation of aOECs improved the neurological function deficits after SCI in rats. More importantly, the crosstalk between JAK1/STAT1/3/6-targeted downstream signals and NF-κB/SOCS1/3 signaling predominantly orchestrates IL-4-modulated microglial polarization event. These results provide new insights into the molecular mechanisms of aOECs driving the M1-to-M2 shift of microglia and shed light on new therapies for SCI through the modulation of microglial polarization.


Assuntos
Curcumina , Traumatismos da Medula Espinal , Animais , Ratos , Microglia , Interleucina-4/farmacologia , Curcumina/farmacologia , Macrófagos , Traumatismos da Medula Espinal/terapia , Anti-Inflamatórios
7.
Bioorg Chem ; 145: 107252, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38437763

RESUMO

Isoquinoline alkaloids are an important class of natural products that are abundant in the plant kingdom and exhibit a wide range of structural diversity and biological activities. With the deepening of research in recent years, more and more isoquinoline alkaloids have been isolated and identified and proved to contain a variety of biological activities and pharmacological effects. In this review, we introduce the research progress of isoquinoline alkaloids from 2019 to 2022, mainly in the part of biological activities, including antitumor, antimicrobial, antidiabetic, antiviral, anti-inflammatory, antioxidant, neuroprotective, hepatoprotective, analgesic, and other activities. This study provides a clear direction for the rational development and utilization of isoquinoline alkaloids, suggesting that these alkaloids have great potential in the field of drug research.


Assuntos
Alcaloides , Anti-Infecciosos , Alcaloides/química , Anti-Infecciosos/farmacologia , Antioxidantes/farmacologia , Isoquinolinas/farmacologia , Isoquinolinas/química
8.
Ren Fail ; 46(1): 2349136, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38770992

RESUMO

BACKGROUND: Research has showcased a correlation between disruptions in gut microbiota and primary membranous nephropathy (pMN), giving rise to the concept of the 'gut-kidney axis'. However, the precise relationship between gut microbiota and pMN remains elusive. Hence, this study endeavors to investigate whether a causal relationship exists between gut microbiota and pMN utilizing Mendelian randomization (MR) analysis. METHODS: The primary method employed for MR analysis is the inverse variance weighting method, supplemented by MR-Egger and the weighted median method, to infer causality. This approach was validated within the pMN cohort across two distinct populations. RESULTS: At the species level, the abundance of Bifidobacterium bifidum and Alistipes indistinctus was negatively correlated with the risk of pMN. Conversely, pMN was positively associated with Bacilli abundance at the class level, Lachnospiraceae abundance at the family level, and Dialister abundance at the genus level. Specifically, at the species level, pMN was positively correlated with the abundance of Ruminococcus lactaris, Dialister invisus, and Coprococcus_sp_ART55_1. CONCLUSION: These findings lay the groundwork for future research exploring the interplay between pMN and the gut microbiota, with substantial implications for the prevention and treatment of pMN and its associated complications.


Assuntos
Microbioma Gastrointestinal , Glomerulonefrite Membranosa , Análise da Randomização Mendeliana , Humanos , Glomerulonefrite Membranosa/microbiologia , Glomerulonefrite Membranosa/genética , Masculino , Feminino , Pessoa de Meia-Idade , Bifidobacterium bifidum , Adulto
9.
Molecules ; 29(8)2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38675717

RESUMO

In the context of peptide drug development, glycosylation plays a pivotal role. Accordingly, L-type peptides were synthesized predicated upon the PD-1/PD-L1 blocker DPPA-1. Subsequent glycosylation resulted in the production of two distinct glycopeptides, D-glu-LPPA-1 and D-gal-LPPA-1, by using D-glucose (D-glu) and D-galactose (D-gal), respectively, during glycosylation. Both glycopeptides significantly inhibited the interaction between PD-1 and PD-L1, and the measured half maximal inhibitory concentrations (IC50s) were 75.5 µM and 101.9 µM for D-glu-LPPA-1 and D-gal-LPPA-1, respectively. Furthermore, D-gal-LPPA-1 displayed a pronounced ability to restore T-cell functionality. In an MC38 tumor-bearing mouse model, D-gal-LPPA-1 demonstrated a significant inhibitory effect. Notably, D-gal-LPPA-1 substantially augmented the abundance and functionality of CD8+ T cells in the tumor microenvironment. Additionally, in the lymph nodes and spleens, D-gal-LPPA-1 significantly increased the proportion of CD8+ T cells secreting interferon-gamma (IFN-γ). These strong findings position D-gal-LPPA-1 as a potent enhancer of the antitumor immune response in MC38 tumor-bearing mice, underscoring its potential as a formidable PD-1/PD-L1 blocking agent.


Assuntos
Antígeno B7-H1 , Receptor de Morte Celular Programada 1 , Glicosilação , Animais , Antígeno B7-H1/metabolismo , Antígeno B7-H1/antagonistas & inibidores , Camundongos , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/metabolismo , Humanos , Desenho de Fármacos , Inibidores de Checkpoint Imunológico/farmacologia , Inibidores de Checkpoint Imunológico/química , Inibidores de Checkpoint Imunológico/síntese química , Glicopeptídeos/química , Glicopeptídeos/síntese química , Glicopeptídeos/farmacologia , Microambiente Tumoral/efeitos dos fármacos , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/metabolismo , Linhagem Celular Tumoral
10.
Mol Cancer ; 22(1): 85, 2023 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-37210576

RESUMO

BACKGROUND: Enhancer of zeste homolog 2 (EZH2), the key catalytic subunit of polycomb repressive complex 2 (PRC2), is overexpressed and plays an oncogenic role in various cancers through catalysis-dependent or catalysis-independent pathways. However, the related mechanisms contributing to ovarian cancer (OC) are not well understood. METHODS: The levels of EZH2 and H3K27me3 were evaluated in 105 OC patients by immunohistochemistry (IHC) staining, and these patients were stratified based on these levels. Canonical and noncanonical binding sites of EZH2 were defined by chromatin immunoprecipitation sequencing (ChIP-Seq). The EZH2 solo targets were obtained by integrative analysis of ChIP-Seq and RNA sequencing data. In vitro and in vivo experiments were performed to determine the role of EZH2 in OC growth. RESULTS: We showed that a subgroup of OC patients with high EZH2 expression but low H3K27me3 exhibited the worst prognosis, with limited therapeutic options. We demonstrated that induction of EZH2 degradation but not catalytic inhibition profoundly blocked OC cell proliferation and tumorigenicity in vitro and in vivo. Integrative analysis of genome-wide chromatin and transcriptome profiles revealed extensive EZH2 occupancy not only at genomic loci marked by H3K27me3 but also at promoters independent of PRC2, indicating a noncanonical role of EZH2 in OC. Mechanistically, EZH2 transcriptionally upregulated IDH2 to potentiate metabolic rewiring by enhancing tricarboxylic acid cycle (TCA cycle) activity, which contributed to the growth of OC. CONCLUSIONS: These data reveal a novel oncogenic role of EZH2 in OC and identify potential therapeutic strategies for OC by targeting the noncatalytic activity of EZH2.


Assuntos
Proteína Potenciadora do Homólogo 2 de Zeste , Neoplasias Ovarianas , Humanos , Feminino , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Histonas/metabolismo , Complexo Repressor Polycomb 2/genética , Complexo Repressor Polycomb 2/metabolismo , Neoplasias Ovarianas/patologia , Metilação , Linhagem Celular Tumoral
11.
BMC Plant Biol ; 23(1): 558, 2023 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-37957575

RESUMO

BACKGROUND: Salt stress severely restricts rapeseed growth and productivity. Hemin can effectively alleviate salt stress in plants. However, the regulatory effect of Hemin on rapeseed in salt stress is unclear. Here, we analyzed the response and remediation mechanism of Hemin application to rapeseed before and after 0.6% (m salt: m soil) NaCl stress. Experiment using two Brassica napus (AACC, 2n = 38) rapeseed varieties Huayouza 158R (moderately salt-tolerant) and Huayouza 62 (strongly salt-tolerant). To explore the best optional ways to improve salt stress resistance in rapeseed. RESULTS: Our findings revealed that exogenous application of Hemin enhanced morph-physiological traits of rapeseed and significantly attenuate the inhibition of NaCl stress. Compared to Hemin (SH) treatment, Hemin (HS) significantly improved seedlings root length, seedlings height, stem diameter and accumulated more dry matter biomass under NaCl stress. Moreover, Hemin (HS) significantly improved photosynthetic efficiency, activities of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase (APX), and decreased electrolyte leakage (EL) and malondialdehyde (MDA) content, thus resulting in the alleviation of oxidative membrane damage. Hemin (HS) showed better performance than Hemin (SH) under NaCl stress. CONCLUSION: Hemin could effectively mitigate the adverse impacts of salt stress by regulating the morph-physiological, photosynthetic and antioxidants traits of rapeseed. This study may provide a basis for Hemin to regulate cultivated rapeseed salt tolerance and explore a better way to alleviate salt stress.


Assuntos
Brassica napus , Brassica rapa , Plântula , Hemina/farmacologia , Cloreto de Sódio/farmacologia , Antioxidantes/farmacologia , Estresse Salino
12.
BMC Plant Biol ; 23(1): 455, 2023 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-37770835

RESUMO

BACKGROUND: Salt stress is one of the key factors limiting rice production. Alginate oligosaccharides (AOS) enhance plant stress resistance. However, the molecular mechanism underlying salt tolerance in rice induced by AOS remains unclear. FL478, which is a salt-tolerant indica recombinant inbred line and IR29, a salt-sensitive rice cultivar, were used to comprehensively analyze the effects of AOS sprayed on leaves in terms of transcriptomic and metabolite profiles of rice seedlings under salt stress. RESULTS: In this experiment, exogenous application of AOS increased SOD, CAT and APX activities, as well as GSH and ASA levels to reduce the damage to leaf membrane, increased rice stem diameter, the number of root tips, aboveground and subterranean biomass, and improved rice salt tolerance. Comparative transcriptomic analyses showed that the regulation of AOS combined with salt treatment induced the differential expression of 305 and 1030 genes in FL478 and IR29. The expressed genes enriched in KEGG pathway analysis were associated with antioxidant levels, photosynthesis, cell wall synthesis, and signal transduction. The genes associated with light-trapping proteins and RLCK receptor cytoplasmic kinases, including CBA, LHCB, and Lhcp genes, were fregulated in response to salt stress. Treatment with AOS combined with salt induced the differential expression of 22 and 50 metabolites in FL478 and IR29. These metabolites were mainly related to the metabolism of amino and nucleotide sugars, tryptophan, histidine, and ß -alanine. The abundance of metabolites associated with antioxidant activity, such as 6-hydroxymelatonin, wedelolactone and L-histidine increased significantly. Combined transcriptomic and metabolomic analyses revealed that dehydroascorbic acid in the glutathione and ascorbic acid cycles plays a vital role in salt tolerance mediated by AOS. CONCLUSION: AOS activate signal transduction, regulate photosynthesis, cell wall formation, and multiple antioxidant pathways in response to salt stress. This study provides a molecular basis for the alleviation of salt stress-induced damage by AOS in rice.


Assuntos
Oryza , Transcriptoma , Plântula/genética , Plântula/metabolismo , Antioxidantes/metabolismo , Oryza/metabolismo , Estresse Salino/genética , Glutationa/metabolismo , Oligossacarídeos/metabolismo , Oligossacarídeos/farmacologia
13.
Stem Cells ; 40(9): 818-830, 2022 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-35728620

RESUMO

Nerve growth factor (NGF) is the best-characterized neurotrophin and is primarily recognized for its key role in the embryonic development of the nervous system and neuronal cell survival/differentiation. Recently, unexpected actions of NGF in bone regeneration have emerged as NGF is able to enhance the osteogenic differentiation of mesenchymal stem cells. However, little is known regarding how NGF signaling regulates osteogenic differentiation through epigenetic mechanisms. In this study, using human dental mesenchymal stem cells (DMSCs), we demonstrated that NGF mediates osteogenic differentiation through p75NTR, a low-affinity NGF receptor. P75NTR-mediated NGF signaling activates the JNK cascade and the expression of KDM4B, an activating histone demethylase, by removing repressive H3K9me3 epigenetic marks. Mechanistically, NGF-activated c-Jun binds to the KDM4B promoter region and directly upregulates KDM4B expression. Subsequently, KDM4B directly and epigenetically activates DLX5, a master osteogenic gene, by demethylating H3K9me3 marks. Furthermore, we revealed that KDM4B and c-Jun from the JNK signaling pathway work in concert to regulate NGF-mediated osteogenic differentiation through simultaneous recruitment to the promoter region of DLX5. We identified KDM4B as a key epigenetic regulator during the NGF-mediated osteogenesis both in vitro and in vivo using the calvarial defect regeneration mouse model. In conclusion, our study thoroughly elucidated the molecular and epigenetic mechanisms during NGF-mediated osteogenesis.


Assuntos
Células-Tronco Mesenquimais , Osteogênese , Animais , Diferenciação Celular/genética , Epigênese Genética , Histona Desmetilases/metabolismo , Humanos , Histona Desmetilases com o Domínio Jumonji/genética , Histona Desmetilases com o Domínio Jumonji/metabolismo , Células-Tronco Mesenquimais/metabolismo , Camundongos , Fator de Crescimento Neural/genética , Fator de Crescimento Neural/metabolismo , Osteogênese/genética , Receptor de Fator de Crescimento Neural/genética , Receptor de Fator de Crescimento Neural/metabolismo
14.
Phytopathology ; 113(1): 11-20, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35913221

RESUMO

Burkholderia contaminans MS14, isolated from a soil sample in Mississippi, is known for producing the novel antifungal compound occidiofungin. In addition, MS14 exhibits a broad range of antibacterial activities against common plant pathogens. Random mutagenesis and gene complementation indicate that four genes are required for antibacterial activity of strain MS14 against the fire blight pathogen Erwinia amylovora. With the aim of finding the biosynthetic gene cluster for the unknown antibacterial compound, we used RNA-seq to analyze the transcriptome of MS14 wild type and mutants lacking antibacterial activity. The twofold lower expressed genes in all mutants were studied, and a polyketide synthase (PKS) gene cluster was predicted to be directly involved in MS14 antibacterial activities. The nptII-resistance cassette and CRISPR-Cas9 systems were used to mutate the PKS gene cluster. Plate bioassays showed that either insertion or frame-shifting one of the PKS genes resulted in a loss of antibacterial activity. Considering that the antibacterial-defective mutants maintain the same antifungal activities as the wild-type strain, the results suggest that this PKS gene cluster is highly likely to be involved in or directly responsible for the production of MS14 antibacterial activity. Purification efforts revealed that the antibacterial activity of the compound synthesized by the gene cluster is sensitive to UV radiation. Nevertheless, these findings have provided more insights to understand the antibacterial activity of strain MS14.


Assuntos
Burkholderia , Policetídeos , Antifúngicos , Ligases/genética , Doenças das Plantas/microbiologia , Burkholderia/genética , Antibacterianos/farmacologia , Família Multigênica
15.
Am J Emerg Med ; 73: 131-136, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37657142

RESUMO

OBJECTIVES: Older patients arrive at the emergency department (ED) with complex medical challenges, and the current ED triage models frequently undertriage the severity of illness in older adults. There is increasing awareness regarding the importance of identifying frailty in older patients in the context of urgent care. Therefore, this study aimed to assess the predictive accuracy of the seven-question tool of the Program on Research for Integrating Services of the Maintenance of Autonomy (PRISMA-7) in the ED for 28-day mortality among older adults. DESIGN: A prospective polycentric observational study. SETTING: West China Hospital of Sichuan University, Shangjinnanfu of West China Hospital, and People's Hospital of Henan Province. PARTICIPANTS: ED patients aged ≥65 years from the three tertiary care centers over an 8-week period. PRIMARY AND SECONDARY OUTCOMES: The primary outcome, 28-day all-cause mortality, was investigated using a Cox proportional hazards regression model to assess the predictive validity. The secondary endpoints, intensive care unit (ICU) transfer was investigated using multivariable logistic regression, compared with trained study assistants. RESULTS: The final study population comprised 1043 consecutive patients aged ≥65 years. The area under the receiver operating characteristic (ROC) curve (AUC) for 28-day mortality was 0.80 (95% confidence interval [CI]: 0.76-0.84), 0.73 (95% CI: 0.68-0.77), and 0.78 (95% CI: 0.73-0.83) for PRISMA-7, Emergency Severity Index (ESI), and quick Sepsis Related Organ Failure Assessment (qSOFA), respectively.There was no difference in the AUC between PRISMA-7 and qSOFA(p = 0.374).The AUC for ICU admission was 0.78 (95% CI: 0.75-0.80), 0.62 (95% CI: 0.59-0.66), and 0.68 (95% CI: 0.64-0.72) for PRISMA-7, ESI, and qSOFA, respectively.The AUC for ICU admission between PRISMA-7 and ESI(p<0.001), PRISMA-7 and qSOFA(p<0.001), qSOFA and ESI(p = 0.005) was statistically significant. CONCLUSION: Our findings reveal that PRISMA-7 improves the prediction of ICU admission, but there is no significant difference when it comes to all-cause mortality. PRISMA-7 appears to be a reliable and valid instrument for identifying frailty in the ED. TRIAL REGISTRATION NUMBER: ChiCTR2100046545.

16.
Food Microbiol ; 115: 104333, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37567623

RESUMO

Natural environment serves as a reservoir for Burkholderia cepacia complex organisms, including the highly transmissible opportunistic human pathogen B. cenocepacia. Currently, there is a lack of an effective and quantitative method for B. cenocepacia detection in fresh food and other environmental niches. A quantitative real-time PCR (qPCR) detection method for B. cenocepacia bacteria was established in this study and validated using artificially inoculated fresh vegetable samples. Genome-wide comparative methods were applied to identify target regions for the design of species-specific primers. Assay specificity was measured with 12 strains of closely related Burkholderia bacteria and demonstrated the primer pair BCF6/R6 were 100% specific for detection of B. cenocepacia. The described qPCR assay evaluated B. cenocepacia with a 2 pg µl-1 limit of detection and appropriate linearity (R2 = 0.999). In 50 samples of experimentally infected produce (lettuce, onion, and celery), the assay could detect B. cenocepacia as low as 2.6 × 102 cells in each sample equal to 1 g. The established qPCR method quantitatively detects B. cenocepacia with high sensitivity and specificity, making it a promising technique for B. cenocepacia detection and epidemiological research on B. cepacia complex organisms from fresh vegetables.


Assuntos
Burkholderia cenocepacia , Complexo Burkholderia cepacia , Humanos , Verduras
17.
Chem Biodivers ; 20(11): e202300998, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37755070

RESUMO

Based on the research strategy of "drug repurposing", a series of derivatives and marketed drugs that containing salicylic acid skeleton were tested for their antibacterial activities against phytopathogens. Salicylic acid can not only regulate some important growth metabolism of plants, but also induce plant disease resistance. The bioassay results showed that the salicylamides exhibited excellent antibacterial activity. Especially, oxyclozanide showed the best antibacterial effect against Xanthomonas oryzae, Xanthomonas axonopodis pv. citri and Pectobacterium atroseptica with MICs of 0.78, 3.12 and 12.5 µg.mL-1, respectively. In vivo experiments with rice bacterial leaf blight had further demonstrated that oxyclozanide exhibited stronger antibacterial activity than the commercial bactericide, thiodiazole copper. Oxyclozanide could induce plant defense responses through the determination of salicylic acid content and the activities of defense-related enzymes including CAT, POD, and SOD in rice. The preliminarily antibacterial mechanism study indicated that oxyclozanide exhibited the antibacterial activity by disrupting cell integrity and reducing bacterial pathogenicity. Additionally, oxyclozanide could induce plant defense responses through the determination of salicylic acid content.


Assuntos
Oryza , Xanthomonas , Salicilamidas/farmacologia , Reposicionamento de Medicamentos , Oxiclozanida/farmacologia , Antibacterianos/farmacologia , Oryza/microbiologia , Testes de Sensibilidade Microbiana , Ácido Salicílico/farmacologia , Doenças das Plantas/prevenção & controle , Doenças das Plantas/microbiologia , Oxidiazóis/farmacologia
18.
Nano Lett ; 22(14): 5735-5741, 2022 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-35850534

RESUMO

Topological surface states are a new class of electronic states with novel properties, including the potential for annihilation between surface states from two topological insulators at a common interface. Here, we report the annihilation and creation of topological surface states in the SnTe/Crx(BiSb)2-xTe3 (CBST) heterostructures as evidenced by magneto-transport, polarized neutron reflectometry, and first-principles calculations. Our results show that topological surface states are induced in the otherwise topologically trivial two-quintuple-layers thick CBST when interfaced with SnTe, as a result of the surface state annihilation at the SnTe/CBST interface. Moreover, we unveiled systematic changes in the transport behaviors of the heterostructures with respect to changing Fermi level and thickness. Our observation of surface state creation and annihilation demonstrates a promising way of designing and engineering topological surface states for dissipationless electronics.

19.
Molecules ; 28(6)2023 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-36985657

RESUMO

Three novel compounds (1-3) along with twenty-six known compounds, two known steroids (4-5) and twenty-four known phenylpropanoids (6-29) were isolated from the whole plant of Thesium chinense Turcz. The structures of the three new compounds were elucidated on the basis of ESI-MS, HR-ESIMS, 1D and 2D NMR, IR, UV spectroscopic data. The absolute stereochemistry of compound 1 was determined by the Gauge-Including Atomic Orbitals (GIAO) method. The in vitro antioxidant, anti-inflammatory and cytotoxic activities of the isolated compounds were evaluated by DPPH radical-scavenging assay, LPS-activated RAW 264.7 cells model and CCK-8 kit, respectively. Compound 11 showed high antioxidant activity with an SC50 value of 16.2 ± 1.6 µM. Compound 21 showed considerable anti-inflammatory activity with an IC50 value of 28.6 ± 3.0 µM. Compounds 4 and 5 displayed potent cytotoxic activity against human NCI-H292, SiHa, A549, and MKN45 cell lines, with the compound 4 having IC50 values of 17.4 ± 2.4, 22.2 ± 1.1, 9.7 ± 0.9, 9.5 ±0.7 µM, and the compound 5 having all IC50 values less than 0.1 µM in vitro.


Assuntos
Antineoplásicos , Antioxidantes , Animais , Camundongos , Humanos , Antioxidantes/farmacologia , Antioxidantes/química , Linhagem Celular , Células RAW 264.7 , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/química , Estrutura Molecular
20.
Pharmazie ; 78(1): 2-5, 2023 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-37138412

RESUMO

To explore potential indoleamine 2,3-dioxygenase 1 (IDO1) inhibitors, we designed a series of compounds incorporating urea and 1,2,3-triazole structures. IDO1 enzymatic activity experiments with the synthesized compounds were used to verify their molecular-level activity; for instance, the half maximal inhibitory concentration value of compound 3c was 0.07 µM. Our research has yielded a series of novel IDO1 inhibitors which may be beneficial in the development of drugs targeting IDO1 for cancer treatment.


Assuntos
Antineoplásicos , Neoplasias , Relação Estrutura-Atividade , Triazóis/farmacologia , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/química , Indolamina-Pirrol 2,3,-Dioxigenase/química , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Antineoplásicos/farmacologia , Neoplasias/tratamento farmacológico
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