Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 52
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Anal Chem ; 96(16): 6170-6179, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38616610

RESUMO

Despite their many important physiological functions, past work on the diverse sequences of human milk oligosaccharides (HMOs) has been focused mainly on the highly abundant HMOs with a relatively low degree of polymerization (DP) due to the lack of efficient methods for separation/purification and high-sensitivity sequencing of large-sized HMOs with DP ≥ 10. Here we established an ultrahigh-temperature preparative HPLC based on a porous graphitized carbon column at up to 145 °C to overcome the anomeric α/ß splitting problem and developed further the negative-ion ESI-CID-MS/MS into multistage MSn using a combined product-ion scanning of singly charged molecular ion and doubly charged fragment ion of the branching Gal and adjacent GlcNAc residues. The separation and sequencing method allows efficient separation of a neutral fraction with DP ≥ 10 into 70 components, among which 17 isomeric difucosylated nona- and decasaccharides were further purified and sequenced. As a result, novel branched difucosyl heptaose and octaose backbones were unambiguously identified in addition to the conventional linear and branched octaose backbones. The novel structures of difucosylated DF-novo-heptaose, DF-novo-LNO I, and DF-novo-LNnO I were corroborated by NMR. The various fucose-containing Lewis epitopes identified on different backbones were confirmed by oligosaccharide microarray analysis.


Assuntos
Leite Humano , Oligossacarídeos , Espectrometria de Massas por Ionização por Electrospray , Humanos , Leite Humano/química , Oligossacarídeos/química , Oligossacarídeos/isolamento & purificação , Oligossacarídeos/análise , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas em Tandem , Temperatura
2.
Genome Res ; 30(1): 22-34, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31804951

RESUMO

Genome-wide association studies indicate that many disease susceptibility regions reside in non-protein-coding regions of the genome. Long noncoding RNAs (lncRNAs) are a major component of the noncoding genome, but their biological impacts are not fully understood. Here, we performed a CRISPR interference (CRISPRi) screen on 2263 epidermis-expressed lncRNAs and identified nine novel candidate lncRNAs regulating keratinocyte proliferation. We further characterized a top hit from the screen, progenitor renewal associated non-coding RNA (PRANCR), using RNA interference-mediated knockdown and phenotypic analysis in organotypic human tissue. PRANCR regulates keratinocyte proliferation, cell cycle progression, and clonogenicity. PRANCR-deficient epidermis displayed impaired stratification with reduced expression of differentiation genes that are altered in human skin diseases, including keratins 1 and 10, filaggrin, and loricrin. Transcriptome analysis showed that PRANCR controls the expression of 1136 genes, with strong enrichment for late cell cycle genes containing a CHR promoter element. In addition, PRANCR depletion led to increased levels of both total and nuclear CDKN1A (also known as p21), which is known to govern both keratinocyte proliferation and differentiation. Collectively, these data show that PRANCR is a novel lncRNA regulating epidermal homeostasis and identify other lncRNA candidates that may have roles in this process as well.


Assuntos
Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Epiderme/metabolismo , Regulação da Expressão Gênica , Estudo de Associação Genômica Ampla , Homeostase , Interferência de RNA , RNA Longo não Codificante/genética , Animais , Biomarcadores , Sistemas CRISPR-Cas , Ciclo Celular/genética , Linhagem Celular , Proteínas Filagrinas , Perfilação da Expressão Gênica , Técnicas de Silenciamento de Genes , Estudo de Associação Genômica Ampla/métodos , Humanos , Queratinócitos/metabolismo , Sistema de Sinalização das MAP Quinases , Camundongos , Organogênese/genética , Regiões Promotoras Genéticas , Transcriptoma
3.
Vet Res ; 54(1): 108, 2023 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-37993950

RESUMO

Lawsonia intracellularis, the etiologic agent of proliferative enteropathy (PE), is an obligate intracellular Gram-negative bacterium possessing a type III secretion system (T3SS), which enables the pathogen to translocate effector proteins into targeted host cells to modulate their functions. T3SS is a syringe-like apparatus consisting of a base, an extracellular needle, a tip, and a translocon. The translocon proteins assembled by two hydrophobic membrane proteins can form pores in the host-cell membrane, and therefore play an essential role in the function of T3SS. To date, little is known about the T3SS and translocon proteins of L. intracellularis. In this study, we first analyzed the conservation of the T3S apparatus between L. intracellularis and Yersinia, and characterized the putative T3S hydrophobic major translocon protein LI1158 and minor translocon protein LI1159 in the L. intracellularis genome. Then, by using Yersinia pseudotuberculosis as a surrogate system, we found that the full-length LI1158 and LI1159 proteins, but not the putative class II chaperone LI1157, were secreted in a - Ca2+ and T3SS-dependent manner and the secretion signal was located at the N terminus (aa 1-40). Furthermore, yeast-two hybrid experiments revealed that LI1158 and LI1159 could self-interact, and LI1159 could interact with LI1157. However, unlike CPn0809 and YopB, which are the major hydrophobic translocon proteins of the T3SS of C. pneumoniae and Yersinia, respectively, full-length LI1158 was non-toxic to both yeast and Escherichia coli cells, but full-length LI1159 showed certain toxicity to E. coli cells. Taken together, despite some differences from the findings in other bacteria, our results demonstrate that LI1158 and LI1159 may be the translocon proteins of L. intracellularis T3SS, and probably play important roles in the translocation of effector proteins at the early pathogen infection stage.


Assuntos
Lawsonia (Bactéria) , Animais , Sistemas de Secreção Tipo III/genética , Sistemas de Secreção Tipo III/metabolismo , Escherichia coli/metabolismo , Saccharomyces cerevisiae , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo
4.
BMC Biol ; 19(1): 79, 2021 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-33863328

RESUMO

BACKGROUND: Rheumatoid arthritis (RA) is a chronic, systemic autoimmune disease that involves a variety of cell types. However, how the epigenetic dysregulations of peripheral immune cells contribute to the pathogenesis of RA still remains largely unclear. RESULTS: Here, we analysed the genome-wide active DNA regulatory elements of four major immune cells, namely monocytes, B cells, CD4+ T cells and CD8+ T cells, in peripheral blood of RA patients, osteoarthritis (OA) patients and healthy donors using Assay of Transposase Accessible Chromatin with sequencing (ATAC-seq). We found a strong RA-associated chromatin dysregulation signature in monocytes, but no other examined cell types. Moreover, we found that serum C-reactive protein (CRP) can induce the RA-associated chromatin dysregulation in monocytes via in vitro experiments. And the extent of this dysregulation was regulated through the transcription factor FRA2. CONCLUSIONS: Together, our study revealed a CRP-induced pathogenic chromatin dysregulation signature in monocytes from RA patients and predicted the responsible signalling pathway as potential therapeutic targets for the disease.


Assuntos
Artrite Reumatoide , Cromatina , Artrite Reumatoide/genética , Linfócitos T CD8-Positivos , Epigenômica , Humanos , Monócitos
5.
Molecules ; 28(1)2022 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-36615221

RESUMO

Polygonum multiflorum Thunb. (PMT), a commonly used Chinese herbal medicine for treating diseases such as poisoning and white hair, has attracted constant attention due to the frequent occurrence of liver injury incidents. To date, its hepatotoxic equivalent markers (HEMs) and potential hepatotoxic mechanisms are still unclear. In order to clarify the HEMs of PMT and further explore the potential mechanisms of hepatotoxicity, firstly, the chemical constituents in PMT extract were globally characterized, and the fingerprints of PMT extracts were established along with the detection of their hepatotoxicity in vivo. Then, the correlations between hepatotoxic features and component contents were modeled by chemometrics to screen HEMs of PMT, which were then further evaluated. Finally, the hepatotoxic mechanisms of PMT were investigated using liver metabolomics and molecular docking. The results show that the chemical combination of 2,3,5,4-tetrahydroxystilbene-2-O-ß-D-glucoside (TSG) and emodin-8-O-glucoside (EG) was discovered as the HEMs of PMT through pre-screening and verifying process. Liver metabolomics revealed that PMT caused liver injury by interfering with purine metabolism, which might be related to mitochondrial function disorder and oxidative injury via the up-regulations of xanthosine and xanthine, and the down-regulation of 5' nucleotidase (NT5E) and adenylate kinase 2 (AK2). This study not only found that the HEMs of PMT were TSG and EG, but also clarified that PMT might affect purine metabolism to induce liver injury, which contributed to our understanding of the underlying mechanisms of PMT hepatotoxicity.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas , Emodina , Fallopia multiflora , Polygonum , Fallopia multiflora/química , Simulação de Acoplamento Molecular , Polygonum/química , Glucosídeos , Purinas
6.
Anal Bioanal Chem ; 413(14): 3683-3693, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33825917

RESUMO

How to achieve simultaneous and rapid detection of various mycotoxins in food has important practical significance in the field of food processing and safety. In this paper, a smartphone immunoassay system based on hydrogel microspheres has been constructed to quickly detect two mycotoxins at the same time. The rapid detection system was reflected in the following three processes: (1) rapid separation of free matter after direct competition reaction based on hydrogel solid-phase carrier particles; (2) rapid detection process based on efficient catalytic function of enzymes; (3) fast capture and analysis of images based on smartphone software. Ochratoxin A (OTA) and zearalenone (ZEN) are secondary toxic metabolites of fungi that can contaminate a wide range of foods and feeds. OTA and ZEN were used as detection model molecules to verify the feasibility of the intelligent rapid detection system. The entire detection process was within 30 min, and the results were analyzed in only 10 s. Detection limits of mycotoxins OTA and ZEN are 0.7711 ng L-1 and 1.0391 ng L-1. The recoveries of both mycotoxins ranged from 76.72 to 122.05%. This study provides a universal rapid detection method for on-site application of large-scale food security testing. Schematic diagram of the construction of the smartphone detection system: The system is divided into three parts: detection, image capture and analysis, and result.


Assuntos
Imunoensaio/métodos , Micotoxinas/análise , Ocratoxinas/análise , Smartphone , Zearalenona/análise , Contaminação de Alimentos/análise , Imunoensaio/economia , Imunoensaio/instrumentação , Limite de Detecção , Fatores de Tempo
7.
Artigo em Inglês | MEDLINE | ID: mdl-32070491

RESUMO

Protein binding events on RNA are highly related to RNA secondary structure, which affects post-transcriptional regulation and translation. However, it remains challenging to describe the association between RNA secondary structure and protein binding events. Here, we present Structure Motif Analysis tool (SMAtool), a pipeline that integrates RNA secondary structure and protein binding site information to profile the binding structure preference of each protein. As an example of applying SMAtool, we extracted the RNA-structure and binding site information respectively from the DMS-seq and eCLIP-seq data of the K562 cell-line, and used SMAtool to analyze the structure motif of each RNA binding protein (RBP). This new approach provided results consistent with X-ray crystallography data from the protein data bank (PDB) database, demonstrating that it can help researchers investigate the structure preference of RBP, and understand the role of RNA secondary structure in gene expression. Availability and implementation: https://github.com/QuKunLab/SMAtool.

8.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 44(1): 9-13, 2019 Jan 28.
Artigo em Zh | MEDLINE | ID: mdl-30837396

RESUMO

OBJECTIVE: To explore differential expression of long non-coding RNA (lncRNA) in patients with coronary artery disease plus clopidogrel resistance.
 Methods: Patients underwent percutaneous coronary intervention (PCI) and treated with clopidogrel were recruited, and their clinical data and blood samples were collected. Patients were divided into a clopidogrel sensitive group and a clopidogrel resistance group according to platelet aggregation rate. lncRNA microarray and real-time RT-PCR were performed in 5 and 34 patients in each group, respectively.
 Results: lncRNA microarray showed that 11 lncRNAs in peripheral leukocytes were up-regulated and 8 lncRNAs were down-regulated in clopidogrel resistant group. Real-time PCR indicated that two lncRNAs (NONHSAT083775.2 and NONHSAT107804.2) in leukocytes were up-regulated and one lncRNA (NONHSAT133455.2) was down-regulated in the clopidogrel resistant group compared with the clopidogrel sensitive group, consistent with the results of lncRNA microarray.
 Conclusion: Clopidogrel resistance is associated with the up-regulation of lncRNA NONHSAT083775.2 and NONHSAT107804.2 and the down-regulation of NONHSAT133455.2.


Assuntos
Doença da Artéria Coronariana , Intervenção Coronária Percutânea , Clopidogrel , Doença da Artéria Coronariana/genética , Humanos , Agregação Plaquetária , Inibidores da Agregação Plaquetária , RNA Longo não Codificante
9.
Drug Metab Dispos ; 46(2): 151-154, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29196299

RESUMO

Clopidogrel acyl glucuronide (CLP-G) is a major phase II metabolite of clopidogrel generated in the liver for further excretion into urine; however, it is unclear whether CLP-G transports from hepatocytes into blood. Because multidrug resistance-associated protein 3 (MRP3) is predominantly expressed in the sinusoidal side of hepatocytes and preferentially transports glucuronide conjugates of drug metabolites from hepatocytes into bloodstream, we hypothesized that MRP3 could be such an efflux transporter for CLP-G. In this study, we compared the liver-to-plasma ratios of clopidogrel and its metabolites (including CLP-G) between Abcc3 (ATP-binding cassette, subfamily C, member 3) knockout (KO) and wild-type (WT) mice. We also evaluated the ATP-dependent uptake of clopidogrel and CLP-G as well as estradiol-17ß-d-glucuronide into human recombinant MRP3 inside-out membrane vesicles in the presence or absence of ATP. The results indicated that the liver-to-plasma ratio of CLP-G was 11-fold higher in KO mice than in WT mice, and that uptake of CLP-G (1 or 10 µM each) into the membrane vesicles was 11.8- and 3.8-fold higher in the presence of ATP than in the presence of AMP, respectively. We conclude that Mrp3 transports CLP-G from the hepatocytes into blood in an ATP-dependent manner.

10.
J Cardiovasc Pharmacol ; 72(5): 252-258, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30358688

RESUMO

Vicagrel, a novel acetate analogue of clopidogrel, exerts more potent antiplatelet effect than clopidogrel in rodents. Relevant evidence indicated that aspirin and vicagrel are the drug substrate for carboxylesterase 2. Accordingly, it is deduced that concomitant use of aspirin could attenuate the bioactivation of and platelet response to vicagrel. To clarify whether there could be such an important drug-drug interaction, the differences in both the formation of vicagrel active metabolite H4 and the inhibition of adenosine diphosphate-induced platelet aggregation by vicagrel were measured and compared between mice treated with vicagrel alone or in combination with aspirin. The plasma H4 concentration was determined by liquid chromatography-tandem mass spectrometry, and the inhibition of platelet aggregation by vicagrel was assessed by whole-blood platelet aggregation. Compared with vicagrel (2.5 mg·kg) alone, concurrent use of aspirin (5, 10, or 20 mg·kg) significantly decreased systemic exposure of H4, an average of 38% and 41% decrease in Cmax and AUC0-∞ in mice when in combination with aspirin at 10 mg·kg, respectively. Furthermore, concomitant use of aspirin (10 mg·kg) and vicagrel (2.5 mg·kg) resulted in an average of 66% reduction in the inhibition of adenosine diphosphate-induced platelet aggregation by vicagrel. We conclude that aspirin significantly attenuates the formation of vicagrel active metabolite H4 and platelet response to vicagrel in mice, and that such an important drug-drug interaction would appear in clinical settings if vicagrel is taken with aspirin concomitantly when marketed in the future.


Assuntos
Aspirina/farmacologia , Plaquetas/efeitos dos fármacos , Fenilacetatos/farmacologia , Inibidores da Agregação Plaquetária/farmacologia , Agregação Plaquetária/efeitos dos fármacos , Tiofenos/farmacologia , Ativação Metabólica , Animais , Aspirina/metabolismo , Plaquetas/metabolismo , Carboxilesterase , Hidrolases de Éster Carboxílico/metabolismo , Cromatografia Líquida , Interações Medicamentosas , Masculino , Camundongos Endogâmicos C57BL , Fenilacetatos/sangue , Fenilacetatos/farmacocinética , Inibidores da Agregação Plaquetária/sangue , Inibidores da Agregação Plaquetária/farmacocinética , Testes de Função Plaquetária , Espectrometria de Massas em Tandem , Tiofenos/sangue , Tiofenos/farmacocinética
11.
Phys Chem Chem Phys ; 20(46): 29249-29263, 2018 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-30427341

RESUMO

Charged lipids in cell membranes and subcellular organelles are arranged in the form of a bilayer with the hydrocarbon tails sequestered away from the water and the polar head groups exposed to the aqueous environment. Most of them bear net negative charges leading to the negatively charged cell membranes. Charged lipid-lipid and lipid-protein interactions are generally dynamic and heavily depend on their local molecular concentrations. To examine the electrostatic properties of charged lipid layers in contact with an electrolyte solution, we incorporate the single chain mean field theory with Poisson-Boltzmann theory to explore the equilibrium structure of charged phospholipid membranes. Using the three bead coarse-grained model we reproduced the essential equilibrium properties of the charged phospholipid bilayer. We also investigate the influence of the mobile ions on the thickness of the layer, the area per lipid (APL), and the electrostatic potential of the membrane. Then we investigate the attraction-repulsion property of two charged nanoparticles which are stuck on the charged lipid molecules surrounded with mobile ions. After that we simulated the interaction between the Pleckstrin homology domain (PH domain) of Akt and the cytoplasmic membrane. Taking into account the electrostatic interaction, we observe the structure changes of the membrane at different concentrations of mobile ions in its equilibrium state. Also we discuss the influence of mobile ions on the size of the pore opened in the membrane by the charged protein. Such an observation may shed light on the activation of oncogenic Akt (or protein kinase B) around the membrane at the molecular level.


Assuntos
Bicamadas Lipídicas/química , Nanopartículas/química , Fosfolipídeos/química , Entropia , Distribuição de Poisson , Eletricidade Estática
12.
Biopharm Drug Dispos ; 39(2): 88-98, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29240983

RESUMO

Clopidogrel is predominantly hydrolyzed to clopidogrel carboxylic acid (CCA) by carboxylesterase 1, and subsequently CCA is glucuronidated to clopidogrel acyl glucuronide (CAG) by uridine diphosphate-glucuronosyltransferases (UGTs); however, the UGT isoenzymes glucuronidating CCA remain unidentified to date. In this study, the glucuronidation of CCA was screened with pooled human liver microsomes (HLMs) and 7 human recombinant UGT (rUGT) isoforms. Results indicated that rUGT2B7 exhibited the highest catalytical activity for the CCA glucuronidation as measured with a mean Vmax value of 120.9 pmol/min/mg protein, 3- to 12-fold higher than that of the other rUGT isoforms tested. According to relative activity factor approach, the relative contribution of rUGT2B7 to CCA glucuronidation was estimated to be 58.6%, with the minor contributions (3%) from rUGT1A9. Moreover, the glucuronidation of CCA followed Michaelis-Menten kinetics with a mean Km value of 372.9 µM and 296.4 µM for pooled HLMs and rUGT2B7, respectively, showing similar affinity for both. The formation of CAG was significantly inhibited by azidothymidine and gemfibrozil (well-characterized UGT2B7 substrates) in a concentration-dependent manner, or by fluconazole (a typical UGT2B7-selective inhibitor) in a time-dependent manner, for both HLMs and rUGT2B7, respectively. In addition, CCA inhibited azidothymidine glucuronidation (catalyzed almost exclusively by UGT2B7) by HLMs and rUGT2B7 in a concentration-dependent manner, indicating that CCA is a substrate of UGT2B7. These results reveal that UGT2B7 is the major enzyme catalyzing clopidogrel glucuronidation in the human liver, and that there is the potential for drug-drug interactions between clopidogrel and the other substrate drugs of UGT2B7.


Assuntos
Glucuronídeos/metabolismo , Glucuronosiltransferase/metabolismo , Ticlopidina/análogos & derivados , Clopidogrel , Interações Medicamentosas , Fluconazol/farmacologia , Genfibrozila/farmacologia , Glucuronosiltransferase/antagonistas & inibidores , Humanos , Isoenzimas/metabolismo , Cinética , Microssomos Hepáticos/metabolismo , Proteínas Recombinantes/metabolismo , Ticlopidina/metabolismo , Zidovudina/farmacologia
13.
J Cardiovasc Pharmacol ; 68(6): 433-440, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27525577

RESUMO

Resistance of the patient to clopidogrel (an inactive prodrug) has been recently reported to be associated with increased messenger RNA expression of ABCC3 that encodes MRP3 (multidrug resistance-associated protein 3). However, there is no evidence showing the effects of MRP3 on altered platelet responses to clopidogrel and their underlying mechanisms. To further clarify whether the presence or absence of Mrp3 could affect the formation of and response to clopidogrel active metabolite (CAM) in Abcc3 knockout (KO) versus wild-type (WT) mice, we determined pharmacokinetic profiles of clopidogrel and CAM and measured inhibition of adenosine diphosphate-induced platelet aggregation by clopidogrel after administration of a single oral dose of clopidogrel to KO and WT mice, respectively. Results indicated that Abcc3 KO mice exhibited increased formation of CAM and greater systemic exposure to clopidogrel and enhanced inhibition of adenosine diphosphate-induced platelet aggregation ex vivo by clopidogrel when compared with well-matched WT mice. We conclude that Abcc3 KO mice have enhanced platelet response to clopidogrel due to increased formation of CAM.


Assuntos
Plaquetas/efeitos dos fármacos , Proteínas Associadas à Resistência a Múltiplos Medicamentos/deficiência , Ativação Plaquetária/efeitos dos fármacos , Inibidores da Agregação Plaquetária/farmacologia , Ticlopidina/análogos & derivados , Animais , Plaquetas/metabolismo , Clopidogrel , Relação Dose-Resposta a Droga , Masculino , Camundongos , Camundongos Knockout , Ativação Plaquetária/fisiologia , Inibidores da Agregação Plaquetária/metabolismo , Ticlopidina/metabolismo , Ticlopidina/farmacologia
14.
Genomics ; 106(4): 242-8, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26188256

RESUMO

With the rapid growth of sequencing technology, a number of genomes and transcriptomes of various species have been sequenced, contributing to the study of lineage-specific genes (LSGs). We identified two sets of LSGs using BLAST: one included Caenorhabditis elegans species-specific genes (1423, SSGs), and the other consisted of Caenorhabditis genus-specific genes (4539, GSGs). The subsequent characterization and analysis of the SSGs and GSGs showed that they have significant differences in evolution and that most LSGs were generated by gene duplication and integration of transposable elements (TEs). We then performed temporal expression profiling and protein function prediction and observed that many SSGs and GSGs are expressed and that genes involved with sex determination, specific stress, immune response, and morphogenesis are over-represented, suggesting that these specific genes may be related to the Caenorhabditis nematodes' special ability to survive in severe and extreme environments.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/genética , Análise de Sequência de RNA/métodos , Animais , Caenorhabditis elegans/fisiologia , Proteínas de Caenorhabditis elegans/metabolismo , Evolução Molecular , Duplicação Gênica , Perfilação da Expressão Gênica , Genoma , Filogenia , Especificidade da Espécie
15.
Zhong Yao Cai ; 38(12): 2543-6, 2015 Dec.
Artigo em Zh | MEDLINE | ID: mdl-27352536

RESUMO

OBJECTIVE: To study the chemical constituents from the roots of Semiliquidambar cathayensis. METHODS: The roots of Semiliquidambar cathayensis were extracted with 80% ethanol for reflux. Chemical constituents were isolated by silica gel chromatography and Sephadex LH-20 column chromatography from petrol ether part and ethyl acetate part of extracts. Their structures were identified on the basis of physico-chemical characters and spectroscopic analysis. RESULTS: Eleven compounds were obtained from the roots of Semiliquidambar cathayensis, and identified as 3-acetyl-12-ene-oleanolic acid methyl ester (1), ß-sitosterol (2), 3-acetyl-12-ene-oleanol-ic acid (3), 2α,3ß-dihydroxy-lup-20(29)-en-28-oic acid (4), (24R)-5α-stignast-3,6-dione (5), betulonic acid (6), stearic acid (7), hexadecanoic acid (8), 3-oxo-olean-12-en-28-oic acid (9), arjunolic acid (10) and daucosterol (11). CONCLUSION: Compounds 1,3 - 6 and 8 are isolated from this genus for the first time.


Assuntos
Hamamelidaceae/química , Compostos Fitoquímicos/análise , Raízes de Plantas/química , Plantas Medicinais/química , Extratos Vegetais/química
16.
World J Microbiol Biotechnol ; 30(3): 1011-7, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24129696

RESUMO

This present study was designed to investigate the production of huperzine A (HupA), an acetylcholine inhibitor, which was produced by an endophytic fungi isolated from Huperzia serrata. Screening of 94 endophytic fungal isolates obtained from plant H. serrata was carried out for the production of HupA. Their morphological characteristics were studied and rDNA sequence analysis was carried out. The cultures were grown in liquid culture medium and the extracted metabolites were analyzed by thin layer chromatography and high performance liquid chromatograph for the presence of HupA. The DPPH scavenging ratio and inhibition ratio of acetylcholinesterase (AchE) of the same were determined. 3 out of 94 strains i.e. S29, L44 and S94 showed significant AchE-inhibitory activity and antioxidant activity. Strain L44 which exhibited maximum yield of HupA (37.63 µg/g on dry weight basis) was identified as Trichoderma species by ITS sequence analysis. In conclusion, endophytic fungi from H. serrata can be used as a new resource of HupA.


Assuntos
Alcaloides/metabolismo , Endófitos/classificação , Endófitos/metabolismo , Huperzia/microbiologia , Sesquiterpenos/metabolismo , Trichoderma/classificação , Trichoderma/metabolismo , Cromatografia Líquida de Alta Pressão , Cromatografia em Camada Fina , Análise por Conglomerados , DNA Fúngico/química , DNA Fúngico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Endófitos/isolamento & purificação , Dados de Sequência Molecular , Filogenia , Análise de Sequência de DNA , Trichoderma/isolamento & purificação
17.
Cell Rep Med ; 5(6): 101580, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38776913

RESUMO

Natural killer (NK) cell-based immunotherapy holds promise for cancer treatment; however, its efficacy remains limited, necessitating the development of alternative strategies. Here, we report that venetoclax, an FDA-approved BCL-2 inhibitor, directly activates NK cells, enhancing their cytotoxicity against acute myeloid leukemia (AML) both in vitro and in vivo, likely independent of BCL-2 inhibition. Through comprehensive approaches, including bulk and single-cell RNA sequencing, avidity measurement, and functional assays, we demonstrate that venetoclax increases the avidity of NK cells to AML cells and promotes lytic granule polarization during immunological synapse (IS) formation. Notably, we identify a distinct CD161lowCD218b+ NK cell subpopulation that exhibits remarkable sensitivity to venetoclax treatment. Furthermore, venetoclax promotes mitochondrial respiration and ATP synthesis via the NF-κB pathway, thereby facilitating IS formation in NK cells. Collectively, our findings establish venetoclax as a multifaceted immunometabolic modulator of NK cell function and provide a promising strategy for augmenting NK cell-based cancer immunotherapy.


Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes , Imunoterapia Adotiva , Células Matadoras Naturais , Leucemia Mieloide Aguda , Sulfonamidas , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Compostos Bicíclicos Heterocíclicos com Pontes/uso terapêutico , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/efeitos dos fármacos , Humanos , Sulfonamidas/farmacologia , Animais , Leucemia Mieloide Aguda/terapia , Leucemia Mieloide Aguda/imunologia , Leucemia Mieloide Aguda/patologia , Camundongos , Imunoterapia Adotiva/métodos , Linhagem Celular Tumoral , NF-kappa B/metabolismo , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Camundongos Endogâmicos NOD
18.
Front Psychol ; 14: 1110642, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37077843

RESUMO

Introduction: This study explored the effects of coping style and two potential intermediately factors (cognitive reappraisal and psychological resilience) on the mental health of middle school students during the normalization of epidemic prevention and control in China. Methods: Answers on questionnaires designed to assess coping style, cognitive reappraisal, psychological resilience, and mental health among 743 middle school students (386 boys, 357 girls, 241 first graders, 235 second graders, and 267 third graders) were analyzed using structural equation modeling. Results: The results showed that coping style, cognitive reappraisal, and psychological resilience directly predicted mental health. The negative effect of a negative coping style on mental health was significantly stronger than the positive effect of a positive coping style. Coping style affected mental health through the independent mediating effects of cognitive reappraisal and psychological resilience and through their chain mediation. Discussion: The use of positive coping styles by most students led to greater cognitive reappraisal, strengthened psychological resilience, and thus few mental health problems. These findings provide empirical evidence and may guide educators in the prevention and intervention of mental health problems among middle school students.

19.
Front Artif Intell ; 6: 1069353, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37035534

RESUMO

Accurate prediction of drug response is a crucial step in personalized medicine. Recently, deep learning techniques have been witnessed with significant breakthroughs in a variety of areas including biomedical research and chemogenomic applications. This motivated us to develop a novel deep learning platform to accurately and reliably predict the response of cancer cells to different drug treatments. In the present work, we describe a Java-based implementation of deep neural network method, termed JavaDL, to predict cancer responses to drugs solely based on their chemical features. To this end, we devised a novel cost function and added a regularization term which suppresses overfitting. We also adopted an early stopping strategy to further reduce overfit and improve the accuracy and robustness of our models. To evaluate our method, we compared with several popular machine learning and deep neural network programs and observed that JavaDL either outperformed those methods in model building or obtained comparable predictions. Finally, JavaDL was employed to predict drug responses of several aggressive breast cancer cell lines, and the results showed robust and accurate predictions with r 2 as high as 0.81.

20.
PeerJ ; 11: e15871, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37927795

RESUMO

Background: To explore the direct effect of core self-evaluation and the indirect effects of positive and negative coping styles on school adaptation of high school students after their return to school during the COVID-19 pandemic. Methods: The Core Self-Evaluation Scale, Simple Coping Style Scale, and School Adaptation Questionnaire were used for the psychometric analysis of 500 high school students (229 males and 271 females) one month after their return to school. The bootstrap method was applied for mediation analysis. Results: A positive correlation was noted between core self-evaluation and school adaptation (r = 0.56), and the predictive effect was significant (ß = 0.43). Core self-evaluation positively predicted positive coping styles, which positively predicted school adaptation, while core self-evaluation negatively predicted negative coping styles, which negatively predicted school adaptation. Positive and negative coping styles played a significant mediating role between core self-evaluation and school adaptation. The mediating effect included the indirect effects generated by two pathways: core self-evaluation → positive coping style → school adaptation (95% CI [0.08-0.19]) and core self-evaluation → negative coping style → school adaptation (95% CI [0.03-0.11]). Conclusion: There is a positive association between the core self-evaluation and school adaptation of high school students after their return to school during the COVID-19 pandemic. It may directly or indirectly affect the school adaptation of high school students after their return to school through positive or negative coping styles. After returning to school, educators should guide students to view themselves positively, cultivate healthy core self-evaluation, and enable them to have good school adaptation.


Assuntos
COVID-19 , Masculino , Feminino , Humanos , COVID-19/epidemiologia , Pandemias , Autoavaliação Diagnóstica , Retorno à Escola , Adaptação Psicológica , Estudantes
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA