Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 132
Filtrar
Mais filtros

País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Apoptosis ; 29(1-2): 121-141, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37848672

RESUMO

Bladder cancer (BLCA) is ranked among the top ten most prevalent cancers worldwide and is the second most common malignant tumor within the field of urology. The limited effectiveness of immune targeted therapy in treating BLCA, due to its high metastasis and recurrence rates, necessitates the identification of new therapeutic targets. Secretogranin II (SCG2), a member of the chromaffin granin/secreted granin family, plays a crucial role in the regulated release of peptides and hormones. The role of SCG2 in the tumor microenvironment (TME) of lung adenocarcinoma and colon cancer has been established, but its functional significance in BLCA remains uncertain. This study aimed to investigate SCG2 expression in 15 bladder cancer tissue samples and their corresponding adjacent control tissues. The potential involvement of SCG2 in BLCA progression was assessed using various techniques, including analysis of public databases, immunohistochemistry, Western Blotting, immunofluorescence, wound-healing assay, Transwell assay, and xenograft tumor formation experiments in nude mice. This study provided novel evidence indicating that SCG2 plays a pivotal role in facilitating the proliferation, migration, and invasion of BLCA by activating the MEK/Erk and MEK/IKK/NF-κB signaling pathways, as well as by promoting M2 macrophage polarization. These findings propose the potential of SCG2 as a molecular target for immunotherapy in human BLCA.


Assuntos
NF-kappa B , Neoplasias da Bexiga Urinária , Animais , Humanos , Camundongos , Apoptose , Cromograninas/uso terapêutico , Camundongos Nus , Quinases de Proteína Quinase Ativadas por Mitógeno , NF-kappa B/genética , NF-kappa B/metabolismo , Secretogranina II/genética , Secretogranina II/metabolismo , Secretogranina II/uso terapêutico , Microambiente Tumoral , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/tratamento farmacológico , Neoplasias da Bexiga Urinária/metabolismo
2.
Opt Express ; 32(3): 3138-3156, 2024 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-38297542

RESUMO

The trade-off between imaging efficiency and imaging quality has always been encountered by Fourier single-pixel imaging (FSPI). To achieve high-resolution imaging, the increase in the number of measurements is necessitated, resulting in a reduction of imaging efficiency. Here, a novel high-quality reconstruction method for FSPI imaging via diffusion model was proposed. A score-based diffusion model is designed to learn prior information of the data distribution. The real-sampled low-frequency Fourier spectrum of the target is employed as a consistency term to iteratively constrain the model in conjunction with the learned prior information, achieving high-resolution reconstruction at extremely low sampling rates. The performance of the proposed method is evaluated by simulations and experiments. The results show that the proposed method has achieved superior quality compared with the traditional FSPI method and the U-Net method. Especially at the extremely low sampling rate (e.g., 1%), an approximately 241% improvement in edge intensity-based score was achieved by the proposed method for the coin experiment, compared with the traditional FSPI method. The method has the potential to achieve high-resolution imaging without compromising imaging speed, which will further expanding the application scope of FSPI in practical scenarios.

3.
Org Biomol Chem ; 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38904076

RESUMO

Carbohydrate-based self-assembling systems are essential for the formation of advanced biocompatible materials via a bottom-up approach. The self-assembling of sugar-based small molecules has applications encompassing many research fields and has been studied extensively. In this focused review, we will discuss the synthetic approaches for carbohydrate-based self-assembling (SA) systems, the mechanisms of the assembly, as well as the main properties and applications. This review will mainly cover recent publications in the last four years from January 2020 to December 2023. We will essentially focus on small molecule self-assembly, excluding polymer-based systems, which include various derivatives of monosaccharides, disaccharides, and oligosaccharides. Glycolipids, glycopeptides, and some glycoconjugate-based systems are discussed. Typically, in each category of systems, the system that can function as low molecular weight gelators (LMWGs) will be discussed first, followed by self-assembling systems that produce micelles and aggregates. The last section of the review discusses stimulus-responsive self-assembling systems, especially those forming gels, including dynamic covalent assemblies, chemical-triggered systems, and photoresponsive systems. The review will be organized based on the sugar structures, and in each category, the synthesis of representative molecular systems will be discussed next, followed by the properties of the resulting molecular assemblies.

4.
Opt Express ; 31(13): 21721-21730, 2023 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-37381262

RESUMO

The lack of three-dimensional (3D) content is one of the challenges that have been faced by holographic 3D display. Here, we proposed a real 3D scene acquisition and 3D holographic reconstruction system based on ultrafast optical axial scanning. An electrically tunable lens (ETL) was used for high-speed focus shift (up to 2.5 ms). A CCD camera was synchronized with the ETL to acquire multi-focused image sequence of real scene. Then, the focusing area of each multi-focused image was extracted by using Tenengrad operator, and the 3D image were obtained. Finally, 3D holographic reconstruction visible to the naked eye can be achieved by the layer-based diffraction algorithm. The feasibility and effectiveness of the proposed method have been demonstrated by simulation and experiment, and the experimental results agree well with the simulation results. This method will further expand the application of holographic 3D display in the field of education, advertising, entertainment, and other fields.

5.
Vet Res ; 54(1): 103, 2023 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-37936178

RESUMO

Duck Tembusu virus (DTMUV) is a neurotropic virus in the genus Flavivirus that causes massive economic losses to the poultry industry in China and neighbouring countries. Autophagy is pivotal in cellular responses to pathogens and in viral pathogenesis. However, little is known about the roles of autophagy in DTMUV replication and viral pathogenesis, especially in neuropathogenesis. In this study, mouse neuroblastoma cells (Neuro-2a) were used to establish a cell model of DTMUV infection. Our experiments indicated that DTMUV infection induced incomplete autophagy in Neuro-2a cells. Then, we used different autophagy regulators to alter the autophagy induced by DTMUV and found that incomplete autophagy promoted DTMUV replication. Furthermore, we showed that DTMUV infection activated the ERK and AMPK pathways, resulting in decreased phosphorylation of the autophagy repressor mTOR, subsequently leading to autophagic induction. In addition, we utilized ICR mice in an animal model of DTMUV infection to evaluate the autophagic responses in brain tissues and investigate the effects of autophagy on viral replication and tissue lesions. Our results confirmed that DTMUV induced incomplete autophagy in mouse brain tissues and that autophagy inducer treatment promoted DTMUV replication and aggravated DTMUV-induced lesions, whereas autophagy inhibitor treatment had the opposite effects. In summary, DTMUV infection induced incomplete autophagy through the ERK/mTOR and AMPK/mTOR signalling pathways to promote viral replication in mouse neuronal cells, and DTMUV-induced incomplete autophagy contributed to the neuropathogenesis of DTMUV.


Assuntos
Infecções por Flavivirus , Flavivirus , Doenças das Aves Domésticas , Animais , Camundongos , Infecções por Flavivirus/veterinária , Proteínas Quinases Ativadas por AMP , Camundongos Endogâmicos ICR , Flavivirus/fisiologia , Replicação Viral , Patos , Serina-Treonina Quinases TOR , Autofagia
6.
Molecules ; 28(16)2023 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-37630308

RESUMO

Carbohydrate-derived molecular gelators have found many practical applications as soft materials. To better understand the structure and molecular gelation relationship and further explore the applications of sugar-based gelators, we designed and synthesized eight trimeric branched sugar triazole derivatives and studied their self-assembling properties. These included glucose, glucosamine, galactose, and maltose derivatives. Interestingly, the gelation properties of these compounds exhibited correlations with the peripheral sugar structures. The maltose derivative did not form gels in the tested solvents, but all other compounds exhibited gelation properties in at least one of the solvents. Glucose derivatives showed superior performance, followed by glucosamine derivatives. They typically formed gels in toluene and alcohols; some formed gels in ethanol-water mixtures or DMSO water mixtures. The glycoclusters 9 and 10 demonstrated rate acceleration for the copper-catalyzed azide-alkyne cycloaddition (CuAAC) reactions. These were further studied for their metallogels formation properties, and the copper metallogels from compound 9 were successfully utilized to catalyze click reactions. These metallogels were able to form a gel column, which was effective in converting the reactants into the triazole products in multiple cycles. Moreover, the same gel column was used to transform a second click reaction using different reactants. The synthesis and characterization of these compounds and their applications for catalytic reactions were discussed.

7.
Molecules ; 28(17)2023 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-37687056

RESUMO

Carbohydrate-based low-molecular-weight gelators are interesting new materials with many potential applications. These compounds can be designed to include multiple stimuli-responsive functional groups. In this study, we designed and synthesized several chemically responsive bola-glycolipids and dimeric carbohydrate- and diarylethene-based photoswitchable derivatives. The dimeric glycolipids formed stable gels in a variety of solvent systems. The best performing gelators in this series contained decanedioic and dithienylethene (DTE) spacers, which formed gels in eight and nine of the tested solvents, respectively. The two new DTE-containing esters possessed interesting photoswitching properties and DTE derivative 7 was found to have versatile gelation properties in many solvents, including DMSO solutions at low concentrations. The gels formed by these compounds were stable under acidic conditions and tended to hydrolyze under basic conditions. Several gels were used to absorb rhodamine B and Toluidine blue from aqueous solutions. In this study, we demonstrated the rational design of molecular gelators which incorporated photoresponsive and pH responsive functions, leading to the discovery of multiple effective stimuli-responsive gelators.

8.
BMC Vet Res ; 18(1): 455, 2022 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-36581820

RESUMO

BACKGROUND: Mycoplasma synoviae (MS) is an important pathogen causing respiratory diseases and arthritis in chickens and turkeys, thus, resulting in serious economic losses to the poultry industry. Membrane-associated proteins are thought to play important roles in cytoadherence and pathogenesis. NADH oxidase (NOX) is an oxidoreductase involved in glycolysis, which is thought to be a multifunctional protein and potential virulence factor in some pathogens. However, little is known regarding the NOX of MS (MSNOX). We previously demonstrated that MSNOX was a metabolic enzyme distributed in not only the cytoplasm but also the MS membrane. This study was aimed at exploring NOX's potential as a diagnostic antigen and its role in MS cytoadherence. RESULTS: Western blots and ELISAs indicated that recombinant MSNOX (rMSNOX) protein reacted with sera positive for various MS isolates, but not MG isolates or other avian pathogens, thus, suggesting that rMSNOX is a potential diagnostic antigen. In addition, rabbit anti-rMSNOX serum showed substantial complement-dependent mycoplasmacidal activity toward various MS isolates and MG Rlow. MSNOX protein was found not only in the cytoplasm but also on the membrane of MS through suspension immunofluorescence and immunogold electron microscopy assays. Indirect immunofluorescence assays indicated that rMSNOX adhered to DF-1 cells, and this adherence was inhibited by rabbit anti-rMSNOX, but not anti-MG serum. Furthermore, indirect immunofluorescence and colony counting assays confirmed that the rabbit anti-rMSNOX serum inhibited the adherence of various MS isolates but not MG Rlow to DF-1 cells. Moreover, plasminogen (Plg)- and fibronectin (Fn)-binding assays demonstrated that rMSNOX bound Plg and Fn in a dose-dependent manner, thereby further confirming that MSNOX may be a putative adhesin. CONCLUSION: MSNOX was identified to be a surface immunogenic protein that has good immunoreactivity and specificity in Western blot and ELISA, and therefore, may be used as a potential diagnostic antigen in the future. In addition, rMSNOX adhered to DF-1 cells, an effect inhibited by rabbit anti-rMSNOX, but not anti-MG serum, and anti-rMSNOX serum inhibited the adherence of various MS isolates, but not MG Rlow, to DF-1 cells, thus indicating that the inhibition of adherence by anti-MSNOX serum was MS specific. Moreover, rMSNOX adhered to extracellular matrix proteins including Plg and Fn, thus suggesting that NOX may play important roles in MS cytoadherence and pathogenesis. Besides, rabbit anti-rMSNOX serum presented complement-dependent mycoplasmacidal activity toward both MS and MG, indicating the MSNOX may be further studied as a potential protective vaccine candidate.


Assuntos
Infecções por Mycoplasma , Mycoplasma synoviae , Doenças das Aves Domésticas , Animais , Coelhos , Fibronectinas/metabolismo , Galinhas , Adesinas Bacterianas , Proteínas de Membrana , Plasminogênio/metabolismo , Infecções por Mycoplasma/diagnóstico , Infecções por Mycoplasma/veterinária , Doenças das Aves Domésticas/prevenção & controle
9.
Appl Intell (Dordr) ; 52(15): 18226-18247, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35855435

RESUMO

Interactive group evaluation is a decision-making method to obtain group consensus by constantly modifying the initial weight of experts. Probabilistic hesitant Pythagorean fuzzy set (PrHPFS) is to be added the corresponding probability values for each membership degree and non-membership degree on the hesitant Pythagorean fuzzy set (HPFS). It is not only a generalization of HPFS and the Pythagorean fuzzy set (PFS), but also a more comprehensive and accurate reflection of the initial decision information given by experts. Especially, it can deal with the decision-making problem of multi-attribute fuzzy information in a wider area. In this paper, some basic definitions and related operations of the probabilistic hesitant Pythagorean fuzzy numbers (PrHPFNs) are first reviewed, and propose score function and accuracy function in PrHPFNs environment. Secondly, the concepts of Hamming distance measure, weighted distance measure and degree of similarity are put forward in PrHPFNs space, and the degree of similarity of two probabilistic hesitant Pythagorean fuzzy matrices (PrHPFMs) is suggested through the aggregation operator formula of PFNs. Finally, an interactive group decision-making method is designed based on the PrHPFM and the degree of similarity under the PrHPFNs environment, the effectiveness of the method is verified by an example, so as to overcome the hesitant psychological state of experts and achieve the consistent consensus evaluation of group preference.

10.
Molecules ; 26(11)2021 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-34205128

RESUMO

Glycomacrolactones exhibit many interesting biological properties, and they are also important in molecular recognitions and for supramolecular chemistry. Therefore, it is important to be able to access glycomacrocycles with different sizes and functionality. A new series of carbohydrate-based macrocycles containing triazole and lactone moieties have been designed and synthesized. The synthesis features an intramolecular nucleophilic substitution reaction for the macrocyclization step. In this article, the effect of some common sulfonate leaving groups is evaluated for macrolactonization. Using tosylate gave good selectivity for monolactonization products with good yields. Fourteen different macrocycles have been synthesized and characterized, of which eleven macrocycles are from cyclization of the C1 to C6 positions of N-acetyl D-glucosamine derivatives and three others from C2 to C6 cyclization of functionalized D-glucosamine derivatives. These novel macrolactones have unique structures and demonstrate interesting anion binding properties, especially for chloride. The macrocycles containing two triazoles form complexes with copper sulfate, and they are effective ligands for copper sulfate mediated azide-alkyne cycloaddition reactions (CuAAC). In addition, several macrocycles show some selectivity for different alkynes.

11.
Microb Pathog ; 147: 104381, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32739401

RESUMO

Hydropericardium-hepatitis syndrome (HHS) is an important emerging disease responsible for huge economic losses to the poultry industry in China. HHS primarily affects 20 to 60-day-old broilers and rarely occurs in laying flock. In this study, the highly pathogenic fowl adenovirus (FAdV) strain, AH-F19, was isolated from the liver samples of 120-day-old laying flock with HHS and its phylogenetic information, genetic mutations, and pathogenicity was evaluated. The phylogenetic analysis revealed that AH-F19 belonged to the FAdV serotype 4 (FAdV-4) cluster, however, 100K differs from the other FAdV-4 strains and is divided into different branches. Amino acid variations in fiber-2 for pathogenic isolates and non-pathogenic isolates indicated that D219, T300, and T380 may not be responsible for virulence. Animal experiments revealed AH-F19 to be a highly pathogenic isolate that can cause 100% mortality in three-week-old specific pathogen-free (SPF) chickens, which exhibited typical hydropericardium and hepatitis. Microscopically, the presence of basophilic intranuclear inclusion bodies in hepatocytes, fractured heart muscle fibers, as well as kidney degeneration and necrosis was observed. Collectively, these findings enriched our understanding of FAdV-4 pathogenicity and provided a reference for further exploration into its pathogenicity.


Assuntos
Infecções por Adenoviridae , Hepatite , Doenças das Aves Domésticas , Adenoviridae , Infecções por Adenoviridae/veterinária , Animais , Galinhas , China , Filogenia , Sorogrupo , Virulência
12.
Cancer Cell Int ; 20: 351, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32742198

RESUMO

BACKGROUND: Gastric cancer is a serious malignant tumor associated with aberrant circular RNAs (circRNAs) expression. In this study, we aim to investigate the role and the underlying mechanism of circ_0000190, a circRNA in gastric cancer. METHODS: Circ_0000190 expression in vivo was examined in gastric cancer and adjacent normal tissues by RT-PCR. Circ_0000190 expression in gastric cancer cell lines was detected by FISH and RT-PCR. The role of the circRNA in gastric cancer cells was assessed by the analysis of cell viability, apoptosis, proliferation, cell cycle and migration. The potential effector of circ_0000190 was predicted by computational screen and validated by luciferase reporter assay. Furthermore, Mice model of human gastric cancer was established to observe the underlying mechanisms of circ_0000190. RESULTS: Circ_0000190 was down-regulated in gastric cancer tissues and cells, with a major location in cytoplasm. Circ_0000190 inhibited gastric cancer cell viability, proliferation and migration, and induced apoptosis and cell cycle arrest by regulating the expression of capase-3, p27 and cyclin D. In addition, the circRNA was validated as a sponge of miR-1252, which directly targeted PAK3. The effects of circ_0000190 on the cellular processes were blocked by miR-1252 mimics, which could be rescued after further overexpression of PAK3. CONCLUSIONS: Circ_0000190 suppresses gastric cancer progression potentially via inhibiting miR-1252/PAK3 pathway, employing circ_0000190 might be a promising therapeutic strategy for the treatment of gastric cancer.

13.
J Org Chem ; 85(24): 16136-16156, 2020 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-33301322

RESUMO

Glycoclusters with three, four, and six arms of glycosyl triazoles were designed, synthesized, and characterized. The self-assembling properties of these molecules and their catalytic activity as ligands in copper-catalyzed azide and alkyne cycloaddition (CuAAC) reactions were studied. The compounds with a lower number of branches exhibit excellent gelation properties and can function as supramolecular gelators. The resulting gels were characterized using optical microcopy and atomic force microscopy. The glycoconjugates containing six branches showed significant catalytic activity for copper sulfate mediated cycloaddition reactions. In aqueous solutions, 1 mol % of glycoclusters to substrates was efficient at accelerating these reactions. Several trimeric compounds were found to be capable of forming co-gels with the catalytically active hexameric compounds. Using the organogels formed by the glycoconjugates as supramolecular catalysts, efficient catalysis was demonstrated for several CuAAC reactions. The metallogels with CuSO4 were also prepared as gel columns, which can be reused for the cycloaddition reactions several times. These include the preparation of a few glycosyl triazoles and aryl triazoles and isoxazoles. We expect that these sugar-based soft biomaterials will have applications beyond supramolecular catalysis for copper-catalyzed cycloaddition reactions. They may also be useful as ligands or gel matrixes for other metal-ion catalyzed organic reactions.

14.
Cell Biol Int ; 44(9): 1890-1899, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32437063

RESUMO

Adjuvant chemotherapy in combination with surgery is expected to be a curative strategy for gastric cancer. However, drug resistance remains an obstacle in effective chemotherapy. Therefore, understanding the potential mechanisms of chemotherapy induced gastric cancer cell death is of great importance. We demonstrated that BIX-01294 (BIX) at low concentration could induce autophagic flux by converting LC3B-I to LC3B-II and directly activate autophagy associated cell death in gastric cancer cell lines at high concentration. BIX at low concentration could help obtain sensitivity of gastric cancer cells to chemotherapy with significantly reduced cell viability. Interestingly, BIX combined Cis (BIX + Cis) treated SGC-7901 cells display pyroptosis related cell death with large bubbles blown around the membrane, significantly decreased cell viability, elevated lactate dehydrogenase release and increased percentage of propidium iodide and Annexin-V double positive cells. Furthermore, the cleavage of gasdermin E (GSDME) and caspase-3 but not GSDMD was detected by immunoblotting and the knockout of GSDME switched pyroptosis into apoptosis in the BIX + Cis combined treated group. Furthermore, the deficiency of Beclin-1 to inhibit BIX induced autophagic flux completely blocked BIX + Cis combined treated induced cell pyroptosis related cell death. Additionally, BIX + Cis in vivo treatment could inhibit tumor growth, which could be reversed by the deficiency of Beclin-1 and be delayed by the deficiency of GSDME. In conclusion, our data was the first to reveal that BIX enhanced the anticancer chemotherapy effect by induced GSDME-mediated pyroptosis through the activation of autophagic flux in gastric cancer cells.


Assuntos
Azepinas/farmacologia , Piroptose/fisiologia , Quinazolinas/farmacologia , Neoplasias Gástricas/tratamento farmacológico , Animais , Apoptose/efeitos dos fármacos , Autofagia , Azepinas/metabolismo , Morte Celular , Linhagem Celular Tumoral , Sobrevivência Celular , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Proteínas de Neoplasias/metabolismo , Piroptose/efeitos dos fármacos , Quinazolinas/metabolismo , Neoplasias Gástricas/metabolismo
15.
Arch Virol ; 165(3): 709-714, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31873767

RESUMO

Duck Tembusu virus (DTMUV) has caused significant economic losses in China since 2010. However, there is still a lack of effective methods to diagnose the disease caused by this virus, and especially to differentiate infection from vaccination. In this study, we established a novel indirect enzyme-linked immunosorbent assay (iELISA) and performed a retrospective serological survey for DTMUV in Anhui province, China. Our results show that the iELISA displayed high specificity sensitivity, and with no serological cross-reaction with other duck pathogens. These findings indicate that the newly developed iELISA could be a useful screening tool for large-scale monitoring of the epidemiology of DTMUV infection in ducks.


Assuntos
Anticorpos Antivirais/sangue , Ensaio de Imunoadsorção Enzimática/métodos , Infecções por Flavivirus/diagnóstico , Flavivirus/imunologia , Doenças das Aves Domésticas/diagnóstico , Proteínas não Estruturais Virais/imunologia , Animais , China , Patos/virologia , Flavivirus/isolamento & purificação , Infecções por Flavivirus/veterinária , Infecções por Flavivirus/virologia , Doenças das Aves Domésticas/virologia , Estudos Retrospectivos , Sensibilidade e Especificidade , Proteínas não Estruturais Virais/genética
16.
Langmuir ; 35(45): 14639-14650, 2019 11 12.
Artigo em Inglês | MEDLINE | ID: mdl-31575116

RESUMO

Carbohydrate-based low-molecular-weight gelators are useful and versatile compounds for the preparation of soft materials. Using N-acetyl-d-glucosamine as the starting material, we synthesized and characterized 15 glycolipids containing an amide with different ester functional groups. These include aliphatic derivatives with varying chain lengths and aromatic derivatives. Most of the hybrid amide-esters have molecular weights less than 500 D. These glycolipids were found to be effective gelators for several organic solvents, water, and aqueous solutions. Two efficient hydrogelators were also obtained at low concentrations. A few representative gels were characterized using optical microscopy, atomic force microscopy, and rheology to obtain information on their morphology and gel stability. Three gelators were also used to encapsulate naproxen sodium and toluidine blue. The sustained release of the drug from the gel to the aqueous phase was monitored by UV-vis spectroscopy. These gelators have structural flexibility that can be stimuli responsive. The esters can be hydrolyzed and several gels were converted to solutions under basic conditions. These rationally designed gelators could be utilized as stimuli-responsive smart materials with controlled release properties.

17.
Org Biomol Chem ; 17(24): 6043-6056, 2019 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-31157348

RESUMO

Carbohydrate based self-assembling supramolecular systems are important classes of new materials with many potential applications. In this study, a series of twelve glycoconjugates were synthesized and characterized in order to obtain effective supramolecular gelators. These glycoconjugates are mono-, di-, tri-, and tetra-functionalized pentaerythritol derivatives synthesized by using copper(i) catalyzed azide alkyne cycloaddition reactions (CuAACs). The properties of these twelve compounds gave insight into the rational design of covalently linking multiple units of sugars. We found that the trivalent and tetravalent glycoclusters were effective molecular gelators, but the monovalent and divalent derivatives were typically not able to form gels in the tested solvents. The gels were characterized using rheology, optical microscopy, and atomic force microscopy. The tris-triazole derivative 21 was discovered to be a suitable gelator for the encapsulation of naproxen, vitamin B2, and vitamin B12. The strategy of covalently linking three or four small molecules to form trimeric or tetrameric branched compounds is a valid approach in designing useful self-assembling materials. The glycocluster based organogels and hydrogels obtained in this study have potential applications in biomedical research and as advanced functional materials.

18.
Biochem Biophys Res Commun ; 495(1): 1418-1425, 2018 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-29183726

RESUMO

Gastric cancer is a malignancy that starts from the cells in the stomach with relatively low overall survival rate. Chemotherapy following resection surgery has been recommended as a curative strategy for gastric cancer. However, the mechanism of the chemotherapy drugs on gastric cancer is not completely understood. Pyroptosis is a form of programmed cell death and plays critical role in immunity. The role of pyroptosis on cancer cells is less known. In this study, we treated SGC-7901 and MKN-45 with 5-FU and found that the cell viability was significantly decreased. The release of LDH and the percentage of PI and APC Annexin-V double positive cells after 5-FU treatment were elevated compared to control group. Moreover, there were large bubbles blowing from the membrane of 5-FU-treated cells and the cleavage of GSDME but not GSDMD, which were blocked by the silence or specific inhibitor of caspase-3. Additionally, GSDME knockout by CRISPR-Cas9 switched 5-FU induced pyroptosis into apoptosis in SGC-7901. In conclusion, our findings firstly revealed that GSDME switches chemotherapy drug-induced caspase-3 dependent apoptosis into pyroptosis in gastric cancer cells.


Assuntos
Caspase 3/metabolismo , Fluoruracila/administração & dosagem , Piroptose/efeitos dos fármacos , Receptores de Estrogênio/metabolismo , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/metabolismo , Antimetabólitos Antineoplásicos/administração & dosagem , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células HL-60 , Humanos , Neoplasias Gástricas/patologia
19.
BMC Microbiol ; 18(1): 225, 2018 12 27.
Artigo em Inglês | MEDLINE | ID: mdl-30587131

RESUMO

BACKGROUND: Pullorum disease, caused by Salmonella enterica serovar Pullorum (S. Pullorum), is one of the most important bacterial infections in the poultry industry in developing countries, including China. To examine the prevalence and characteristics of S. Pullorum, the Multilocus Sequence Typing (MLST) genotypes, fluoroquinolones resistance, and biofilm-forming abilities of S. Pullorum isolates were investigated, collected from 2011 to 2016 in China. RESULTS: Thirty S. Pullorum isolates collected from 2011 to 2016 were analyzed. Quinolones susceptibility testing showed that 90% of the isolates were resistant to the first generation of quinolines nalidixic acid, but the resistance rates to different fluoroquinolones agents were lower than 13.3%; for some there was even no resistance. Multilocus sequence typing (MLST) showed that ST-92 was the dominating genotype, accounting for 90.0% of all S. pullorum strains. The remaining three isolates were of the new reported sequence type ST-2151. Interestingly, the Asp87Gly substitution in quinolone resistance-determining regions (QRDR) of GyrA was only observed in the three strains of ST-2151, suggesting a potential correlation between Asp87Gly substitution and sequence type (p < 0.05). However, Asp87Gly substitution could not confer the resistant to ofloxacin and ciprofloxacin of these isolates. The plasmid-mediated quinolone resistance (PMQR) gene was not found in any of the tested isolates. Furthermore, an assay measuring biofilm-forming abilities showed that 46.7% of the isolates were non-biofilm producers, while 53.3% could form very weak biofilms, which might explain the relatively lower resistance to fluoroquinolones. CONCLUSIONS: We reported a high resistance rate to the first generation of quinolines nalidixic acid and relatively low resistance rates to fluoroquinolones in S. Pullorum isolates. In addition, weak biofilm-forming abilities were found, which might be an important reason of the low fluoroquinolones resistance rates of S. Pullorum isolates. ST-92 was the dominating genotype demonstrated by MLST, and the new sequence type ST-2151 showed a potential correlation with Asp87Gly substitution in QRDR of GyrA. We believe the characterization of these S. Pullorum isolates will be helpful to develop prevention and control strategies.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Doenças das Aves Domésticas/microbiologia , Quinolonas/farmacologia , Salmonelose Animal/microbiologia , Salmonella enterica/efeitos dos fármacos , Salmonella enterica/genética , Animais , Galinhas , China , Ciprofloxacina/farmacologia , Genótipo , Humanos , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Fenótipo , Salmonella enterica/classificação , Salmonella enterica/isolamento & purificação , Sorogrupo
20.
FASEB J ; 31(4): 1337-1353, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28011649

RESUMO

Mammalian cells respond to various environmental stressors to form stress granules (SGs) by arresting cytoplasmic mRNA, protein translation element, and RNA binding proteins. Virus-induced SGs function in different ways, depending on the species of virus; however, the mechanism of SG regulation of virus replication is not well understood. In this study, Newcastle disease virus (NDV) triggered stable formation of bona fide SGs on HeLa cells through activating the protein kinase R (PKR)/eIF2α pathway. NDV-induced SGs contained classic SG markers T-cell internal antigen (TIA)-1, Ras GTPase-activating protein-binding protein (G3BP)-1, eukaryotic initiation factors, and small ribosomal subunit, which could be disassembled in the presence of cycloheximide. Treatment with nocodazole, a microtubule disruption drug, led to the formation of relatively small and circular granules, indicating that NDV infection induces canonical SGs. Furthermore, the role of SGs on NDV replication was investigated by knockdown of TIA-1 and TIA-1-related (TIAR) protein, the 2 critical components involved in SG formation from the HeLa cells, followed by NDV infection. Results showed that depletion of TIA-1 or TIAR inhibited viral protein synthesis, reduced extracellular virus yields, but increased global protein translation. FISH revealed that NDV-induced SGs contained predominantly cellular mRNA rather than viral mRNA. Deletion of TIA-1 or TIAR reduced NP mRNA levels in polysomes. These results demonstrate that NDV triggers stable formation of bona fide SGs, which benefit viral protein translation and virus replication by arresting cellular mRNA.-Sun, Y., Dong, L., Yu, S., Wang, X., Zheng, H., Zhang, P., Meng, C., Zhan, Y., Tan, L., Song, C., Qiu, X., Wang, G., Liao, Y., Ding, C. Newcastle disease virus induces stable formation of bona fide stress granules to facilitate viral replication through manipulating host protein translation.


Assuntos
Grânulos Citoplasmáticos/metabolismo , Interações Hospedeiro-Patógeno , Vírus da Doença de Newcastle/fisiologia , Replicação Viral , Animais , Proteínas de Transporte/metabolismo , Células Cultivadas , Galinhas , DNA Helicases , Fator de Iniciação 2 em Eucariotos/metabolismo , Células HeLa , Humanos , Vírus da Doença de Newcastle/metabolismo , Vírus da Doença de Newcastle/patogenicidade , Proteínas de Ligação a Poli(A)/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose , Biossíntese de Proteínas , RNA Helicases , Proteínas com Motivo de Reconhecimento de RNA , Proteínas de Ligação a RNA , Subunidades Ribossômicas/metabolismo , Antígeno-1 Intracelular de Células T , eIF-2 Quinase/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA