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1.
Plant Divers ; 46(2): 274-279, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38807915

RESUMO

Flower constancy describes the phenomenon that pollinators tend to successively visit flowers of a single species during foraging, reducing reproductive interference in natural communities. The extent of flower constancy is largely determined by the floral traits of co-flowering species. Both higher inter-specific and lower intraspecific differences of floral traits should contribute to a higher level of flower constancy. However, previous studies mainly focused on interspecific difference, and the intraspecific variation (consistency) of floral traits received much less attention. We hypothesise that selection may favour lower intraspecific floral trait variation in communities composed of multiple co-flowering congeners. We investigated the floral colour variation of three focal Pedicularis species that share pollinators in 19 communities composed of either single or multiple Pedicularis species. Colour was quantified using image-based colour analysis as perceived by pollinators. We found that most of the intrapopulation floral colour variation was below the colour discrimination threshold of bumblebees, implying strongly constrained by the visual selection by pollinators. Contrary to the hypothesis, there is no significant difference in intraspecific floral colour variation between different community contexts. It may be due to the relatively large interspecific floral colour differences of most co-flowering species. The influence of community context on intraspecific variation may be reflected in floral traits other than colours.

2.
Cancer Lett ; 584: 216615, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38199586

RESUMO

The biological role of B7-H1 intrinsic signal is reportedly diverse and controversial, its signal pathway remains unclear. Although B7-H1 blocking antibodies were found to have agonist capacity, their binding features and agonist mechanisms need further investigation. Here, by constructing cell strains with full-length or truncated B7-H1, we found that B7-H1 functioned as a receptor to transmit cell death signal from PD-1 protein or anti-B7-H1s through its cytoplasmic domain. Specific binding to the IgV-like domain of B7-H1 was required for the downstream signal. Upon agonists interaction, B7-H1 regulated the degradation of phosphoinositide 3-kinases (PI3Ks) subunit p110γ, subsequently inhibited the PI3K/AKT/mTOR pathway, and significantly increased autophagy. Moreover, B7-H1 agonists also suppressed ubiquitylation in B7-H1+cells by reducing ubiquitin-activating enzyme (E1), eventually leading to cell death. Finally, we validated the receptor role of B7-H1 in multiple tumor cells and demonstrated that B7-H1 agonists could suppress tumor progression independent of T cells in vivo. Our findings revealed that B7-H1 agonists functions as a PI3K inhibitor and may offer new strategies for PI3K targeting therapy.


Assuntos
Fosfatidilinositol 3-Quinases , Proteínas Proto-Oncogênicas c-akt , Antígeno B7-H1/metabolismo , Morte Celular , Classe Ib de Fosfatidilinositol 3-Quinase , Agonistas dos Receptores Histamínicos , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Serina-Treonina Quinases TOR/metabolismo
3.
Environ Res ; 242: 117775, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38029815

RESUMO

The development of cost-efficient biochar adsorbent with a simple preparation method is essential to constructing efficient wastewater treatment system. Here, a low-cost waste carton biochar (WCB) prepared by a simple two-step carbonization was applied in efficiently removing Rhodamine B (RhB) in aqueous environment. The maximum ability of WCB for RhB adsorption was 222 mg/g, 6 and 10 times higher than both of rice straw biochar (RSB) and broadbean shell biochar (BSB), respectively. It was mainly ascribed to the mesopore structure (3.0-20.4 nm) of WCB possessing more spatial sites compared to RSB (2.2 nm) and BSB (2.4 nm) for RhB (1.4 nm✕1.1 nm✕0.6 nm) adsorption. Furthermore, external mass transfer (EMT) controlled mass transfer resistance (MTR) of the RhB sorption process by WCB which was fitted with the Langmuir model well. Meanwhile, the adsorption process was dominated by physisorption through van der Waals forces and π-π interactions. A mixture of three dyes in river water was well removed by using WCB. This work provides a straightforward method of preparing mesoporous biochar derived from waste carton with high-adsorption capacity for dye wastewater treatment.


Assuntos
Carvão Vegetal , Águas Residuárias , Poluentes Químicos da Água , Corantes/química , Eliminação de Resíduos Líquidos/métodos , Adsorção , Poluentes Químicos da Água/análise , Cinética
4.
Angew Chem Int Ed Engl ; 62(46): e202311158, 2023 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-37738210

RESUMO

Herein, we introduce a variety of azopolyesters (azobenzene-based polyesters) with remarkable intrinsic crystallinity and photoinduced reversible solid-to-liquid transition abilities from copolymerization of azobenzene-based epoxides with cyclic anhydrides. The length of the soft alkyl side-chain inlaid with azobenzenes and stereoregularity of main-chain of azopolymers have tremendous effects on crystallization properties of the resulting polyesters with melting temperature (Tm ) in the range of 51-251 °C. Moreover, some of azopolyesters possess excellently photoinduced reversible solid-to-liquid transition performance thanks to trans-cis photoisomerization of azobenzenes. Trans-azopolyesters are yellow solids with Tm s or glass transition temperatures (Tg s) above room temperature, whereas cis-polymers are red liquids with Tg s below -20 °C. These azopolyesters could be applied as novel light-switchable adhesives for quartz/quartz, wood/wood and quartz/wood adhesion, with the strength in the range of 0.73-0.89 MPa for trans-polymers. Conversely, the adhesion strength of liquefied cis-azopolyesters generated from the irradiation of trans-polymers by UV light was about 0.1 MPa, which shows light enable to control the adhesion process with high spatiotemporal resolution.

5.
Opt Express ; 31(8): 13503-13517, 2023 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-37157487

RESUMO

Optimizing the atomic layer deposition (ALD) process of films is particularly important in preparing multilayer interference films. In this work, a series of Al2O3/TiO2 nano-laminates with a fixed growth cycle ratio of 1:10 were deposited on Si and fused quartz substrates at 300 °C by ALD. The optical properties, crystallization behavior, surface appearance and microstructures of those laminated layers were systematically investigated by spectroscopic ellipsometry, spectrophotometry, X-ray diffraction, atomic force microscope and transmission electron microscopy. By inserting Al2O3 interlayers into TiO2 layers, the crystallization of the TiO2 is reduced and the surface roughness becomes smaller. The TEM images show that excessively dense distribution of Al2O3 intercalation leads to the appearance of TiO2 nodules, which in turn leads to increased roughness. The Al2O3/TiO2 nano-laminate with a cycle ratio 40:400 has relatively small surface roughness. Additionally, oxygen-deficient defects exist at the interface of Al2O3 and TiO2, leading to evident absorption. Using O3 as an oxidant instead of H2O for depositing Al2O3 interlayers was verified to be effective in reducing absorption during broadband antireflective coating experiments.

6.
J Sci Food Agric ; 103(3): 1541-1549, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36197122

RESUMO

BACKGROUND: Phthalates (PEs), such as butyl benzyl phthalate, dibutyl phthalate and di(2-ethylhexyl) phthalate, are one of the most widely used plasticizers, and humans are increasingly exposed to them. Phytochemical quercetin (Que) is a typical flavonoid with several biological effects, such as antioxidative and anti-inflammatory. The present study was designed to explore the effect of Que on testicular toxicity caused by the mixture of three commonly used PEs (MPEs), and the underlying mechanism. Forty male Sprague-Dawley rats were randomly and equally divided into five groups (n = 8). Rats in control the group were orally treated with the excipient. Rats in the MPEs group were orally administered with 900 mg kg-1 day-1 MPEs, whereas rats in the MPEs+L-Que, MPEs+M-Que and MPEs+H-Que groups were simultaneously treated with 900 mg kg-1 day-1 MPEs and, respectively, 10, 30 and 90 mg kg-1 day-1 Que for 30 days. RESULTS: Compared with the control group, the testes weight, epididymides weight, serum testosterone, luteinizing hormone, follicle-stimulating hormone and estradiol levels, and anogenital distance in the MPEs group were significantly decreased (P < 0.05). The testicular tissues were injured with atrophy of seminiferous tubules, hyperplasia of Leydig cells and arrest of spermatogenesis in the MPEs group. Testicular steroidogenic proteins (StAR, P450scc, CYP17A1 and 17ß-HSD, P450arom) were up-regulated, whereas P-element-induced wimpy testis proteins (PIWIL1 and PIWIL2) were down-regulated in the MPEs group (P < 0.05). However, the alterations of these parameters were inhibited in the MPEs+M-Que and MPEs+H-Que groups. CONCLUSION: MPEs disturbed steroid hormone metabolism and caused testicular injuries. Que could inhibit testicular toxicity of MPEs, which might relate to the improved regulation of steroid hormone metabolism. © 2022 Society of Chemical Industry.


Assuntos
Dietilexilftalato , Testículo , Humanos , Ratos , Masculino , Animais , Quercetina/farmacologia , Quercetina/metabolismo , Testosterona , Ratos Sprague-Dawley , Dietilexilftalato/metabolismo , Dietilexilftalato/farmacologia , Proteínas Argonautas/metabolismo , Proteínas Argonautas/farmacologia
7.
Toxicol Res (Camb) ; 11(5): 863-871, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36337248

RESUMO

Humans are increasingly exposed to ubiquitous phthalates (PEs), e.g. butyl benzyl phthalate (BBP), dibutyl phthalate (DBP), and di(2-ethylhexyl) phthalate (DEHP), which are widely used plasticizers in polymer products. This study was aimed to investigate the effect of phytochemical quercetin (Que) on hepatotoxicity caused by the mixture of the 3 commonly used PEs (MPEs), and further to explore the underlying mechanism. Forty male Sprague-Dawley rats were randomly divided into control group, MPEs group, and MPEs combined Que at Low-, Median-, and High-dose groups; rats in MPEs group were orally administered with 900 mg/kg/d MPEs, whereas rats in MPEs combined Que groups were simultaneously treated with 900 mg/kg/d MPEs and respectively 10, 30, and 90 mg/kg/d Que. The intervention last 30 days. Compared with control group, serum ALT, AST, LDH and AKP, and hepatic MDA, SOD, CAT and GPx were significantly increased, whereas, serum albumin and total protein were significantly decreased in MPEs group (P < 0.05); hepatic histopathological observation showed numerous inflammatory cells infiltration, hepatocyte ballooning degeneration, and numerous residual erythrocytes in the central vein in MPEs group. Western-blot analysis showed that hepatic Keap1 was downregulated, whereas Nrf2 and HO-1 were upregulated in MPEs group (P < 0.05). However, the alterations of these parameters were alleviated in MPEs combined Que at Median- and High-dose groups. The results indicated that MPEs-induced hepatic oxidative stress, and caused hepatic injuries; whereas, Que inhibited MPEs' hepatotoxicity, which might relate to Que's ability of quenching free radicals directly, and restored the regulation of Nrf2 signaling pathway.

8.
Bioresour Technol ; 349: 126883, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35192946

RESUMO

Here, a low-cost acid-base and temperature tolerant algal bloom derived activated carbon (ABAC) was successfully prepared to remove rhodamine B (RhB) from water. The ABAC exhibited maximum adsorption capacity of RhB (1101 ± 11 mg/g), higher than that of laboratory-prepared rape straw activated carbon (176 ± 5 mg/g) and commercial activated carbon (489 ± 5 mg/g). It is attributed to larger surface area and mesoporous structure of the ABAC. Furthermore, the effective adsorption of RhB by using ABAC was achieved at a wide range of solution pH (3.2-10.8) and temperature(25-50 °C). The mass transfer resistance of RhB adsorption process well depicted by Langmuir model was controlled by external mass transfer. The adsorption process involved both secondly chemisorption (H-bonds and π-π interaction) and dominated physisorption. Four dyes in river water were efficiently removed. This work provides a promising approach for developing high-absorption biomass materials for actual dye wastewater treatment.


Assuntos
Carvão Vegetal , Poluentes Químicos da Água , Adsorção , Carvão Vegetal/química , Corantes , Eutrofização , Concentração de Íons de Hidrogênio , Cinética , Temperatura , Águas Residuárias , Poluentes Químicos da Água/química
9.
Front Oncol ; 11: 690188, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34249740

RESUMO

Although abscopal tumor regression remains a rare phenomenon, interest in exploiting how radiation stimulates the immune system to induce systemic abscopal response is increasing. Here, we tested the hypothesis that tumor immunogenicity determined the ability of radiotherapy to induce abscopal effects. We established highly (MC-38 and E.G7-OVA) or poorly (LL/2 and B16-F10) immunogenic tumor models in this study and treated them with sham radiation, a single dose of 15 Gy, or three fractions of 5 Gy on three consecutive days. Alterations in the tumor microenvironment after radiation were examined by flow cytometry and RNA sequencing. Our results demonstrated the positive correlation between tumor immunogenicity and the abscopal effect of radiotherapy. The single dose of 15 Gy radiation was an effective regimen for inducing abscopal effects in highly immunogenic tumors. Local radiation reshaped the tumor microenvironment of irradiated and non-irradiated distant tumors by increasing CD8 T-cell infiltration and reducing suppressive immune cell accumulation. However, radiation alone was insufficient to elicit abscopal effects in poorly immunogenic tumors. No significant alterations were detected in the non-irradiated distant tumor microenvironment after radiation of poorly immunogenic tumors. In addition, tumor immunogenic subtypes were associated with the radiological response and clinical outcome of patients receiving radiotherapy. These findings indicated that tumor immunogenicity was the dominant characteristic that could predict the abscopal effect of radiotherapy. Our study provides an in-depth understanding of the immunological mechanisms involved in abscopal effects and highlights the impact of tumor heterogeneity on the therapeutic efficacy of radiotherapy and their combination with immunotherapy in clinical trials.

10.
Chemistry ; 27(50): 12753-12757, 2021 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-34173276

RESUMO

Low-concentration ethane capture is crucial for environmental protection and natural gas purification. The ideal physisorbent with strong C2 H6 interaction and large C2 H6 uptake at low-concentration level has rarely been reported, due to the large pKa value and small quadrupole moment of C2 H6 . Herein, we demonstrate the perfectly size matching between the ultramicropore (pore size of 4.6 Å) and ethane (kinetic diameter of 4.4 Å) in a nickel pyridine-4-carboxylate metal-organic framework (IISERP-MOF2), which enables the record-breaking performance for low concentration C2 H6 capture. IISERP-MOF2 exhibits the large C2 H6 adsorption enthalpy of 56.7 kJ/mol, and record-high C2 H6 uptake at low pressure of 0.01-0.1 bar and 298 K (1.8 mmol/g at 0.01 bar). Molecule simulations and C2 H6 -loading crystal structure analysis revealed that the maximized interaction sites in IISERP-MOF2 with ethane molecule originates the strong C2 H6 adsorption. The dynamic breakthrough experiments for gas mixtures of C2 H6 /N2 (1/999, v/v) and C2 H6 /CH4 (5/95, v/v) proved the excellent low-concentration C2 H6 capture performance.


Assuntos
Gases , Estruturas Metalorgânicas , Adsorção , Termodinâmica
11.
Chemistry ; 27(36): 9446-9453, 2021 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-33837618

RESUMO

Rigid molecular sieving materials are the ideal candidates for gas separation (e. g., C2 H2 /C2 H4 ) due to their ultrahigh adsorption selectivity and the absence of gas co-adsorption. However, the absolute molecular sieving effect for C2 H2 /C2 H4 separation has rarely been realized because of their similar physicochemical properties. Herein, we demonstrate the absolute molecular sieving of C2 H2 from C2 H4 by a rigid ultra-microporous metal-organic framework (F-PYMO-Cu) with 1D regular channels (pore size of ca. 3.4 Å). F-PYMO-Cu exhibited moderate acetylene uptake (35.5 cm3 /cm3 ), but very low ethylene uptake (0.55 cm3 /cm3 ) at 298 K and 1 bar, yielding the second highest C2 H2 /C2 H4 uptake ratio of 63.6 up to now. One-step C2 H4 production from a binary mixture of C2 H2 /C2 H4 and a ternary mixture of C2 H2 /CO2 /C2 H4 at 298 K was achieved and verified by dynamic breakthrough experiments. Coupled with excellent thermal and water stability, F-PYMO-Cu could be a promising candidate for industrial C2 separation tasks.

12.
Inorg Chem ; 59(18): 13019-13023, 2020 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-32865397

RESUMO

The pore-size effect on ethane adsorption and ethane/ethylene separation in three isostructural metal azolate frameworks (MAF-123-Mn/Zn/Cu) were thoroughly investigated. MAF-123-Mn/Zn/Cu were synthesized by the solvothermal method on a gram scale. Decreasing the pore size from 6.1 to 4.9 Å leads to an increase in the ethane adsorption energy from 23 to 27.5 kJ mol-1 and further ethane/ethylene separation efficiency. Molecule simulations revealed that a shorter ethane-framework interaction distance in MAF-123-Zn than that in MAF-123-Mn is responsible for the increased adsorption energy. Dynamic breakthrough experiments manifest that these metal azolate frameworks can effectively produce high-purity ethylene from ethane in one adsorption step.

13.
Science ; 366(6462): 241-246, 2019 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-31601769

RESUMO

Purification of ethylene (C2H4), the largest-volume product of the chemical industry, currently involves energy-intensive processes such as chemisorption (CO2 removal), catalytic hydrogenation (C2H2 conversion), and cryogenic distillation (C2H6 separation). Although advanced physisorbent or membrane separation could lower the energy input, one-step removal of multiple impurities, especially trace impurities, has not been feasible. We introduce a synergistic sorbent separation method for the one-step production of polymer-grade C2H4 from ternary (C2H2/C2H6/C2H4) or quaternary (CO2/C2H2/C2H6/C2H4) gas mixtures with a series of physisorbents in a packed-bed geometry. We synthesized ultraselective microporous metal-organic materials that were readily regenerated, including one that was selective for C2H6 over CO2, C2H2, and C2H4.

14.
Fitoterapia ; 136: 104186, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31150769

RESUMO

Five new amide alkaloids, named delamide A-E (1-5), along with five known ones, methyl-N-(3-carboxy-2-methylpropanoyl) anthranilate (6), benzoic acid, 2-[(1-oxodecyl) amino]-methylester (7), puberline (8), benzoic acid, 2-[(4-methoxy-2-methyl-1, 4-dioxobutyl) amino]-methylester (9) and benzoic acid, 2-[(4-methoxy-3-methyl-1, 4-dioxobutyl) amino]-methylester (10) were isolated from the extract of Delphinium brunonianum. Their structures were elucidated by extensive spectroscopic analyses (including 1D-, 2D-NMR, and HR-ESI-MS). 1-10 were also evaluated for their acetylcholinesterase (AChE) inhibiting activity by the Ellman's method. Delamide A (1) showed highly selective AChE inhibition activity. The kinetic analysis revealed that 1 was a mixed-type reversible inhibitor of AChE.


Assuntos
Alcaloides/farmacologia , Inibidores da Colinesterase/farmacologia , Delphinium/química , Componentes Aéreos da Planta/química , Alcaloides/isolamento & purificação , Inibidores da Colinesterase/isolamento & purificação , Estrutura Molecular , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Tibet
15.
Front Immunol ; 10: 2857, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31921127

RESUMO

The successful generation of T cell-mediated immunity for the treatment of cancer has been a major focal point of research. One of the critical strategies of cancer immunotherapy is to efficiently activate antigen-specific CD8 T cells in the immunosuppressive tumor environment. Here, we used transgenic OT-I/CD45.2/Rag-/- mice as a source of effector CD8 T cells to determine whether irradiation combined with adoptive T cell transfer therapy could improve T cell proliferation and effector function in murine tumor models. Local irradiation combined with adoptive T cell therapy showed a synergistic effect on tumor growth inhibition in mice. Mechanistically, irradiation increased the release of tumor-associated antigens, which facilitated cross-presentation of tumor-associated antigens by dendritic cells and the priming of antigen-specific T lymphocytes. Additionally, irradiation enhanced the homing of the antigen-specific T cells to tumor tissues via the increased release of CCL5, CXCL9, and CXCL11 from tumor cells. Moreover, irradiation enhanced the proliferation and effector function of both adoptively transferred T cells and endogenous antigen-specific T cells. Our findings provide evidence to support that local irradiation enhanced the therapeutic efficacy of adoptive T cell therapy for cancer, indicating that the combination of radiotherapy and adoptive T cell therapy may be a promising strategy for tumor treatment.


Assuntos
Transferência Adotiva , Linfócitos T CD8-Positivos , Neoplasias Experimentais , Animais , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/patologia , Linfócitos T CD8-Positivos/transplante , Camundongos , Camundongos Knockout , Neoplasias Experimentais/patologia , Neoplasias Experimentais/terapia , Dosagem Radioterapêutica
16.
Molecules ; 24(1)2018 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-30585251

RESUMO

The metabolic and pharmacokinetic studies on complanatuside, a quality marker of a Chinese materia medicatonic, Semen Astragali Complanati, were carried out. The UHPLC-Q-TOF/MS (ultra-high performance liquid chromatography coupled with electrospray ionization tandem quadrupole-time-of-flight mass spectrometry) method was applied to identify the metabolites of complanatuside in rat plasma, bile, stool, and urine after oral administration at the dosage of 72 mg/kg. Up to 34 metabolites (parent, 2 metabolites of the parent drug, and 31 metabolites of the degradation products) were observed, including processes of demethylation, hydroxylation, glucuronidation, sulfonation, and dehydration. The results indicated glucuronidation and sulfonation as major metabolic pathways of complanatuside in vivo. Meanwhile, a HPLC-MS method to quantify complanatuside and its two major metabolites-rhamnocitrin 3-O-ß-glc and rhamnocitrin-in rat plasma for the pharmacokinetic analysis was developed and validated. The Tmax (time to reach the maximum drug concentration) of the above three compounds were 1 h, 3 h, and 5.3 h, respectively, while the Cmax (maximum plasma concentrations)were 119.15 ng/mL, 111.64 ng/mL, and 1122.18 ng/mL, and AUC(0-t) (area under the plasma concentration-time curve) was 143.52 µg/L·h, 381.73 µg/L·h, and 6540.14 µg/L·h, accordingly. The pharmacokinetic characteristics of complanatuside and its two metabolites suggested that complanatuside rapidly metabolized in vivo, while its metabolites-rhamnocitrin-was the main existent form in rat plasma after oral administration. The results of intracorporal processes, existing forms, and pharmacokinetic characteristics of complanatuside in rats supported its low bioavailability.


Assuntos
Flavonóis/metabolismo , Flavonóis/farmacocinética , Glucosídeos/metabolismo , Glucosídeos/farmacocinética , Administração Oral , Animais , Cromatografia Líquida de Alta Pressão , Flavonóis/administração & dosagem , Glucosídeos/administração & dosagem , Masculino , Metabolômica , Ratos , Ratos Sprague-Dawley , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em Tandem
17.
Oncol Rep ; 33(4): 1630-8, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25652880

RESUMO

High mobility group box-B1 (HMGB1), an autophagy activator, is crucial in tumorigenesis. However, its extracellular role and signaling in gastric cancer remain unclear. Samples were collected from gastric cancer patients and healthy controls. Immunohistochemistry and immunocytochemistry were used to determine the localization of HMGB1 in gastric cancer tissues, four gastric carcinoma cell lines (BGC-823, SGC-7901, MKN-28 and MKN-45) and a gastric epithelial cell line GES-1. Western blot analysis and ELISA were used to assess the effects of gefitinib, an epidermal growth factor receptor inhibitor, on autophagy and HMGB1 release in BGC-823 cells. MTT assay and western blot analysis assessed the effects of extracellular HMGB1 on cell proliferation and signaling transduction. Released HMGB1 promoted proliferation through activation of ERK1/2 MAPK. HMGB1 expression in gastric cancer tissues and serum was significantly increased compared to the controls and healthy serum. Gastric carcinoma cells showed an increased HMGB1 in the nuclei and cytoplasm, whereas GES-1 cells exhibited a lower HMGB1 with nuclear localization. Gefitinib increased autophagy and cytoplasmic HMGB1 release from the BGC-823 cells. Extracellular HMGB1 in autophagic cell supernatant promoted proliferation that was abolished by glycyrrhizic acid, an HMGB1 inhibitor. BGC-823 cells incubated with HMGB1 had increased ERK1/2 phosphorylation, while levels of JNK, p38 or AKT were not affected. Blocking RAGE­HMGB1 interaction with antibody or siRNA suppressed the ERK1/2 activation and gastric cancer cell growth, indicating that RAGE-mediated ERK1/2 signaling was necessary for tumor progression.


Assuntos
Adenocarcinoma/patologia , Autofagia/fisiologia , Proteína HMGB1/fisiologia , Sistema de Sinalização das MAP Quinases , Proteínas de Neoplasias/fisiologia , Receptor para Produtos Finais de Glicação Avançada/fisiologia , Neoplasias Gástricas/patologia , Adenocarcinoma/sangue , Adenocarcinoma/química , Antineoplásicos/farmacologia , Autofagia/efeitos dos fármacos , Sobrevivência Celular , Citoplasma/metabolismo , Ativação Enzimática , Líquido Extracelular/química , Gefitinibe , Proteína HMGB1/sangue , Humanos , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Proteínas de Neoplasias/sangue , Inibidores de Proteínas Quinases/farmacologia , Quinazolinas/farmacologia , Interferência de RNA , RNA Interferente Pequeno/genética , Neoplasias Gástricas/sangue , Neoplasias Gástricas/química , Transfecção
18.
Sci Rep ; 4: 7308, 2014 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-25471817

RESUMO

High-quality protein crystals of suitable size are an important prerequisite for applying X-ray crystallography to determine the 3-dimensional structure of proteins. However, it is often difficult to obtain protein crystals of appropriate size and quality because nucleation and growth processes can be unsuccessful. Here, we show that by adsorbing proteins onto porous polystyrene-divinylbenzene microspheres (SDB) floating on the surface of the crystallisation solution, a localised high supersaturation region at the surface of the microspheres and a low supersaturation region below the microspheres can coexist in a single solution. The crystals will easily nucleate in the region of high supersaturation, but when they grow to a certain size, they will sediment to the region of low supersaturation and continue to grow. In this way, the probability of crystallisation and crystal quality can be simultaneously increased in a single solution without changing other crystallisation parameters.

19.
Physiol Plant ; 146(3): 363-73, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22578286

RESUMO

Zeaxanthin (Z) has a role in the dissipation of excess excitation energy by participating in non-photochemical quenching (NPQ) and is essential in protecting the chloroplast from photooxidative damage. To investigate the physiological effects and functional mechanism of constitutive accumulation of Z in the tomato at salt stress-induced photoinhibition and photooxidation, antisense-mediated suppression of zeaxanthin epoxidase transgenic plants and the wild-type (WT) tomato were used. The ratio of Z/(V + A + Z) and (Z + 0.5A)/(V + A + Z) in antisense transgenic plants were maintained at a higher level than in WT plants under salt stress, but the value of NPQ in WT and transgenic plants was not significantly different under salt stress. However, the maximal photochemical efficiency of PSII (Fv/Fm) and the net photosynthetic rate (Pn) in transgenic plants decreased more slowly under salt stress. Furthermore, transgenic plants showed lower level of hydrogen peroxide (H(2)O(2)), superoxide anion radical (O(2)(•-)) and ion leakage, lower malondialdehyde content. Compared with WT, the content of D1 protein decreased slightly in transgenic plants under salt stress. Our results suggested that the constitutive accumulation of Z in transgenic tomatoes can alleviate salt stress-induced photoinhibition because of the antioxidant role of Z in the scavenging quenching of singlet oxygen and/or free radicals in the lipid phase of the membrane.


Assuntos
Regulação da Expressão Gênica de Plantas/fisiologia , Oxirredutases/genética , Fotossíntese/efeitos da radiação , Cloreto de Sódio/farmacologia , Solanum lycopersicum/fisiologia , Xantofilas/metabolismo , Antioxidantes/metabolismo , Clorofila/metabolismo , Cloroplastos/metabolismo , Peróxido de Hidrogênio/metabolismo , Luz , Peroxidação de Lipídeos , Solanum lycopersicum/efeitos dos fármacos , Solanum lycopersicum/genética , Solanum lycopersicum/efeitos da radiação , Malondialdeído/metabolismo , Oxirredutases/metabolismo , Fotossíntese/efeitos dos fármacos , Complexo de Proteína do Fotossistema II/genética , Folhas de Planta , Plantas Geneticamente Modificadas , RNA Antissenso/genética , RNA de Plantas/genética , Plântula , Estresse Fisiológico , Superóxidos/metabolismo , Xantofilas/análise , Zeaxantinas
20.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi ; 27(12): 1298-300, 2011 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-22152809

RESUMO

AIM: To investigate the effect of fractalkine on the expression of the tumor necrosis factor-α(TNF-α), interleukin-1ß (IL-1ß), and nitric oxide (NO) in LPS-activated murine microglia cells line N9. METHODS: In vitro LPS-activated microglia cells were treated for 24 h in the presence of fractalkine. The level of TNF-α and IL-1ß in the culture supernatants were measured by enzyme-linked immunosorbent assay (ELISA), The level of NO in the culture supernatants were quantitated by the NO test assay. RESULTS: The concentration of TNF-α, IL-1ß and NO in the culture supernatants evidently increased in LPS-activated microglia cells groups and prominently decreased by the fractalkine co-incubated. CONCLUSION: It is thus concluded that fractalkine has neuroprotective functions by inhibiting the expression of inflammatory factor in activated microglia cells.


Assuntos
Quimiocina CX3CL1/farmacologia , Interleucina-1beta/biossíntese , Lipopolissacarídeos/farmacologia , Microglia/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Óxido Nítrico/biossíntese , Fator de Necrose Tumoral alfa/biossíntese , Animais , Células Cultivadas , Camundongos , Microglia/metabolismo
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