Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 21
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
ACS Nano ; 17(14): 13195-13210, 2023 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-37256771

RESUMO

Radiotherapy (RT) is one of the important clinical treatments for local control of triple-negative breast cancer (TNBC), but radioresistance still exists. Ferroptosis has been recognized as a natural barrier for cancer progression and represents a significant role of RT-mediated anticancer effects, while the simultaneous activation of ferroptosis defensive system during RT limits the synergistic effect between RT and ferroptosis. Herein, we engineered a tumor microenvironment (TME) degradable nanohybrid with a dual radiosensitization manner to combine ferroptosis induction and high-Z effect based on metal-organic frameworks for ferroptosis-augmented RT of TNBC. The encapsulated l-buthionine-sulfoximine (BSO) could inhibit glutathione (GSH) biosynthesis for glutathione peroxidase 4 (GPX4) inactivation to break down the ferroptosis defensive system, and the delivered ferrous ions could act as a powerful ferroptosis executor via triggering the Fenton reaction; the combination of them induces potent ferroptosis, which could synergize with the surface decorated Gold (Au) NPs-mediated radiosensitization to improve RT efficacy. In vivo antitumor results revealed that the nanohybrid could significantly improve the therapeutic efficacy and antimetastasis efficiency based on the combinational mechanism between ferroptosis and RT. This work thus demonstrated that combining RT with efficient ferroptosis induction through nanotechnology was a feasible and promising strategy for TNBC treatment.


Assuntos
Ferroptose , Neoplasias de Mama Triplo Negativas , Humanos , Anestésicos Locais , Butionina Sulfoximina , Fibrinolíticos , Glutationa , Linhagem Celular Tumoral , Microambiente Tumoral
2.
Foods ; 12(1)2023 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-36613414

RESUMO

In this study, fresh lotus leaves at two maturity stages were processed to tea products by different methods (white-tea process, green-tea process and black-tea process). The volatile compounds, phytochemical profiles and antioxidant activities of lotus-leaf tea were investigated. A total of 81 volatile components were identified with HS-GC-IMS. The mature lotus-leaf tea showed more volatile compounds than the tender lotus-leaf tea. The lotus leaf treated with the white-tea process had more aroma components than other processing methods. In addition, six types of phenolic compounds, including luteolin, catechin, quercetin, orientin, hyperoside and rutin were identified in the lotus-leaf tea. The mature leaves treated with the green-tea process had the highest levels of TPC (49.97 mg gallic acid/g tea) and TFC (73.43 mg rutin/g tea). The aqueous extract of lotus-leaf tea showed positive scavenging capacities of DPPH and ABTS radicals, and ferric ion reducing power, whereas tender lotus leaf treated with the green-tea process exhibited the strongest antioxidant activity. What is more, the antioxidant activities had a significant positive correlation with the levels of TPC and TFC in lotus-leaf tea. Our results provide a theoretical basis for the manufacture of lotus-leaf-tea products with desirable flavor and health benefits.

3.
Artigo em Inglês | MEDLINE | ID: mdl-35805841

RESUMO

The accelerated urbanization process in China has caused a shift in the urban land use structure. The Chinese government has issued 'the National New-type Urbanization Plan' focusing on the rational use of resources, which is of great significance for the intensification and sustainability of land use. In promoting the construction of the new-type urbanization (N-TU), enhancing the urban land use efficiency (ULUE) is crucial to regional coordinated development. This study uses panel data from 2011 to 2020 for 11 provinces (cities) in the Yangtze River Economic Belt (YREB) and adopts the super efficiency (SE) slacks-based measure (SBM) model with undesirable outputs and the entropy weight method to calculate the ULUE and N-TU levels. The study uses the System generalized method of moment (Sys-GMM) to study the N-TU's impact on the ULUE empirically. The results indicate: (i) the overall trend of new-type urbanization level is gradually increasing and has the characteristics of uneven spatial distribution between provinces. (ii) The ULUE shows a fluctuating upward trend during the studied period. (iii) The N-TU and its subsystems have significant positive effects on the ULUE. Overall, this study aims to explore the relationship between the N-TU and ULUE enriching the theoretical analysis and empirical research in related fields, thus helping decision makers in the assessment and design of policy recommendations.


Assuntos
Rios , Urbanização , China , Cidades , Desenvolvimento Econômico , Eficiência
4.
Food Sci Nutr ; 10(4): 1081-1092, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35432976

RESUMO

Approximately 90% of the cholesterol content of the body is derived from de novo synthesis and the enterohepatic circulation. As numerous studies have shown previously, one egg per day intake has little impact of cholesterol balance in human body. Therefore, this study assumed that intake of up two eggs a day has little effect on biomarkers of cardiovascular diseases (CVDs) risk in Chinese young adults. With the increase in egg intake, total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and choline all increased among all the groups as the study progressed from autumn to winter (p < .05). However, there were no differences in the plasma triglycerides, LDL-C/HDL-C ratio, glucose, liver enzymes, C-reactive protein, and urinary microalbumin during the diet periods. Subjects who ate eggs at breakfast felt less hungry and more satisfied, which were relative with decreased fasting plasma ghrelin level (p < .05). Furthermore, egg-derived cholesterol appeared to upregulate the mRNA levels of low-density lipoprotein receptor and lecithin-cholesterol acyltransferase, and downregulate cholesteryl ester transfer protein and flavin-containing monooxygenase 3 mRNA levels in isolated peripheral blood mononuclear cells. These results demonstrate that intake of up to two eggs a day had little effect on biomarkers of CVDs in young, healthy Chinese college students and provided useful evidence for the dietary guidelines regarding egg consumption.

5.
Environ Sci Pollut Res Int ; 29(22): 33372-33382, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35029832

RESUMO

In this study, we aimed to evaluate phthalate metabolite levels in pregnant women, to explore the factors influencing exposure, and to assess phthalate metabolite levels in relation to thyroid hormone synthesis. We recruited 463 pregnant women and collected urine, blood, and questionnaire data at participant's first prenatal examination. Ten phthalate metabolites were analyzed: mono-isobutyl phthalate (MiBP); mono-methyl phthalate (MMP); mono-ethyl phthalate (MEP); mono-n-butyl phthalate (MnBP); mono-n-octyl phthalate (MOP); mono-benzyl phthalate (MBzP); and the metabolite of di-2-ethylhexyl phthalate (DEHP), which were mono (2-ethylhexyl) phthalate, mono-(2-ethyl-5-oxohexyl) phthalate, and mono-(2-ethyl-5-carboxypentyl) phthalate. Multivariable generalized estimating equation models and linear mixed models were used to predict urinary biomarker concentrations and to assess the associations between phthalate exposure and thyroid hormones. Positive associations were found between phthalate metabolites and lower education (MEP and MOP), living near the road (MEP, MnBP, and ∑DEHP), and consuming more puffed food (MEP and MBzP). In addition, MnBP (percent change [%△] = 4.25; 95% confidence interval [CI] = 0.32, 8.18) and ∑DEHP (%△ = 5.12; 95% CI = 1.25, 8.99) were positively associated with thyroid-stimulating hormones, although MEP and MnBP were inversely associated with free thyroxine and total triiodothyronine. Our findings suggest that certain habits and behaviors were predictive of the positive presence of phthalate metabolites and that certain phthalate esters are associated with altered thyroid hormone levels.


Assuntos
Poluentes Ambientais , Ácidos Ftálicos , Exposição Ambiental , Poluentes Ambientais/metabolismo , Feminino , Humanos , Ácidos Ftálicos/metabolismo , Gravidez , Gestantes , Hormônios Tireóideos , Tireotropina
6.
Nat Prod Res ; 36(4): 1009-1013, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33111556

RESUMO

The main targets of this work were to evaluate the antioxidative properties of flavonoids in Jerusalem artichoke (Helianthus tuberosus L.) leaves and quantitatively determine their contents. 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azino-bis (3-ethylbenzothiazoline)-6-sulphonic acid (ABTS) and hydroxyl free radicals scavenging assays were performed to determine their antioxidative capacities. The validated ultra high-performance liquid chromatography-quadrupole-time-of-flight/mass spectrometry (UHPLC-Q-TOF/MS) method was subsequently applied to the quality evaluation of eleven batches of Jerusalem artichoke leaves grown in different habitats at different harvesting time. Results indicated that two flavonoids isolated from Jerusalem artichoke leaves showed stronger antioxidant effects than the positive control, butylated hydroxytoluene (BHT). And the total contents of the two flavonoids in the Jerusalem artichoke leaves of flowering stage from Dalian, Liaoning Province, China, were the highest, their contents varied significantly depending on region and harvesting time. This study indicated that the leaves of Jerusalem artichoke possessed excellent antioxidant properties, highlighting their candidacy as natural antioxidants, which could be utilized therapeutically to protect the body from diseases caused by oxidative stress.


Assuntos
Helianthus , Antioxidantes/química , Flavonoides/química , Helianthus/química , Extratos Vegetais/química , Folhas de Planta/química
7.
Sci Total Environ ; 803: 150104, 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-34525736

RESUMO

China has pledged to achieve peak carbon emissions by 2030 and to be carbon neutral by the mid-century, and buildings will be the "last mile" sector in the transition to carbon neutrality. To help buildings hit the carbon peak goal, we investigate the different emission scales of carbon emission changes of residential and commercial building operations across 30 provinces in China through the carbon Kuznets curve (CKC) model. We observe that (1) more than three-quarters of the samples can be fitted by the CKC model. Most CKCs are the inverted U-shaped, residential and commercial buildings occupying 93% and 90% at the total emission scale, respectively. In addition, the remains can be illustrated as N-shaped curves. (2) Under the premise of CKCs existence, approximately half of the provincial residential and commercial buildings peak at different emission scales, except for emission per floor space (residential: 89%; commercial: 81%). Provinces with better economic development have a higher peaking probability. In the total emissions, the peaking probability in residential buildings is 33% and 50% for provinces with economic indicators <20,000 Chinese Yuan and 30,000-40,000 Chinese Yuan, respectively, and 22% and 67% for commercial buildings, respectively. (3) Taking carbon intensity as a case study, decoupling analysis examines the robustness of the CKC estimation. Overall, we close the gap of the CKC estimation in commercial and residential buildings, and the proposed methods can be treated as a tool for other economies to illustrate the retrospective and prospective trajectories of carbon emissions in building operations.


Assuntos
Dióxido de Carbono , Carbono , Carbono/análise , Dióxido de Carbono/análise , China , Desenvolvimento Econômico , Estudos Prospectivos , Estudos Retrospectivos
8.
Front Nutr ; 8: 769181, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34805250

RESUMO

This study aimed to extract polysaccharides from pumpkin, characterize the structures of four of them, and evaluate their in vitro antioxidant and hypoglycemic activities. Additionally, an animal model of type 2 diabetes mellitus (T2DM) was established and used to determine their hypoglycemic and hypolipidemic effects in vivo, and the underlying mechanisms related to the regulation of gut microbiota. Water-extracted crude pumpkin polysaccharides (W-CPPs), water extraction and alcohol precipitation crude pumpkin polysaccharides (WA-CPPs), deproteinized pumpkin polysaccharides (DPPs), and refined pumpkin polysaccharides (RPPs) were sequentially extracted and purified from pumpkin powder by hot water extraction, water extraction, and alcohol precipitation, deproteinization and DEAE-52 cellulose gel column, respectively. The extraction and purification methods had significant influence on the extraction yield, physicochemical properties, and in vitro antioxidant and hypoglycemic activities. W-CCP and RPPs had a significant positive free radical-scavenging capacities and inhibitory activities on α-glucosidase and α-amylase. RPP-3 not only inhibited the uptake of glucose in Caco-2 monolayer but also promoted the excretion of glucose, while RPP-2 had no inhibitory effect. Animal experiment results showed that W-CPP treatment significantly improved the T2DM symptoms in mice, which included lowering of fasting blood glucose (FBG), reducing insulin resistance (IR), and lowering of blood lipid levels. It increased the diversity of intestinal flora and reduced the harmful flora of model mice, which included Clostridium, Thermoanaerobe, Symbiotic bacteria, Deinococcus, Vibrio haematococcus, Proteus gamma, and Corio. At the family level, W-CPP (1,200 mg/kg) treatment significantly reduced the abundance of Erysipelotrichaceae, and the Akkermanaceae of Verrucobacterium became a biomarker. Pumpkin polysaccharides reshaped the intestinal flora by reducing Erysipelotrichaceae and increasing Akkermansia abundance, thereby improving blood glucose and lipid metabolism in the T2DM mice. Our results suggest that W-CCP and RPP-3 possess strong antioxidant and hypoglycemic activities, and are potential candidates for food additives or natural medicines.

9.
Exp Cell Res ; 407(1): 112791, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34418457

RESUMO

Long non-coding RNAs (lncRNAs) were reported to be involved in tumorigenesis and progression of hepatocellular carcinoma (HCC). Microvascular invasion (MVI) is an independent predictor for early recurrence and overall survival in postoperative patients with HCC. However, the mechanisms how lncRNAs affect HCC and MVI remain elusive. By RNA sequencing (RNA-seq) in a series of 65 HCC samples and 30 paired adjacent non-tumor liver tissue, we identified a novel lncRNA AC104958.2 that was significantly upregulated in HCC tissues and associated with MVI. Overexpression of AC104958.2 obviously elevated cell viability, metastasis, invasion and epithelial-mesenchymal transition (EMT), while knockout of AC104958.2 mediated by CRISPR/Cas9 technique showed the opposite effects. In addition, the interaction between AC104958.2 and Poly (rC) binding protein 2 (PCBP2) was identified by RNA pull down and mass spectrometry (MS), which was further validated by RNA immunoprecipitation (RIP). PCBP2 was also upregulated in HCC and associated with MVI. High expression of both AC104958.2 and PCBP2 was correlated with tumor size, TNM stage and MVI in HCC. Overexpression of PCBP2 greatly increased the cell viability, metastasis, invasion and EMT. Moreover, actinomycin D assay showed that overexpression of PCBP2 enhanced the RNA stability of AC104958.2. In conclusion, our study showed that a novel lncRNA AC104958.2 exerted oncogenic roles in HCC and might be a promising biomarker and therapeutic target.


Assuntos
Carcinoma Hepatocelular/genética , Proliferação de Células/fisiologia , Neoplasias Hepáticas/metabolismo , RNA Longo não Codificante/genética , Proteínas de Ligação a RNA/metabolismo , Biomarcadores Tumorais/genética , Carcinogênese/genética , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Movimento Celular/genética , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , RNA Longo não Codificante/metabolismo , Regulação para Cima
10.
Molecules ; 24(21)2019 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-31694314

RESUMO

Lotus seed epicarp, the main by-product of lotus seed processing, is abundant in polyphenols. In this study, polyphenols in lotus seed epicarp were separated by Sephadex LH-20 gel filtration chromatography to yield Fraction-I (F-I), Fraction-II (F-II), and Fraction-III (F-III). The polyphenol compounds in the three fractions were identified by UPLC-MI-TOF-MS. Six kinds of polyphenol compounds including cyanidin-3-O-glucoside, procyanidin trimer, and phlorizin were identified in F-I, and prodelphinidin dimer B, procyanidin dimer, and quercetin hexoside isomer were found in F-II. However, there was only procyanidin dimer identified in F-III. The in vitro antioxidant activities of the three fractions were also investigated. We found F-I, F-II, and F-III had strong potential antioxidant activities in the order of F-III > F-II > F-I. Our results suggested that polyphenols from lotus seed epicarp might be suitable for use as a potential food additive.


Assuntos
Antioxidantes/química , Lotus/química , Polifenóis/química , Sementes/química , Antocianinas/química , Biflavonoides/química , Catequina/química , Cromatografia Líquida de Alta Pressão/métodos , Glucosídeos/química , Extratos Vegetais/química , Proantocianidinas/química
11.
Theranostics ; 9(10): 2967-2983, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31244936

RESUMO

The devastating prognosis of hepatocellular carcinoma (HCC) is partially attributed to chemotherapy resistance. Accumulating evidence suggests that the epithelial-mesenchymal transition (EMT) is a key driving force of carcinoma metastasis and chemoresistance in solid tumors. Leucine-rich repeat-containing G protein-coupled receptor 5 (Lgr5), as an EMT inducer, is involved in the potentiation of Wnt signaling in HCC. This study proposes uncovering the roles of Lgr5 in Doxorubicin (Dox) resistance of HCC to improve treatment efficacy for HCC. Methods: We investigated the expression and significance of Lgr5 in HCC tissue and different cell lines. The effect of Lgr5 in EMT and Dox resistance was analyzed in HCC cells and implanted HCC tumor models. A two-hybrid analysis, using the Lgr5 gene as the bait and a HCC cDNA library, was used to screen targeted proteins that interact with Lgr5. The positive clones were identified by coimmunoprecipitation (Co-IP) and Glutathione-S-transferase (GST) pull-down. The impact of the interaction on Dox resistance was investigated by a series of assays in vitro and in vivo . Result: We found that Lgr5 was upregulated and positively correlated with poor prognosis in HCC. Additionally, it functioned as a tumor promoter to increase cell migration and induce EMT in HCC cells and increase the resistance to Dox. We identified programmed cell death protein 5 (PDCD5) as a target gene of Lgr5 and we found that PDCD5 was responsible for Lgr5-mediated Dox resistance. Further analysis with Co-IP and GST pull-down assays showed that the N-terminal extracellular domain of Lgr5 could directly bind to PDCD5. Lgr5 induced p53 degradation by blocking the nuclear translocation of PDCD5 and leading to the loss of p53 stabilization. Lgr5 showed a protection against the inhibition of Dox on the growth of tumor subcutaneously injected. Moreover, Lgr5 suppressed Dox-induced apoptosis via the p53 pathway and attenuated the cytotoxicity of Dox to HCC. Conclusion: Lgr5 induces the EMT and inhibits apoptosis, thus promoting chemoresistance by regulating the PDCD5/p53 signaling axis. Furthermore, Lgr5 may be a potential target gene for overcoming Dox resistance.


Assuntos
Antibióticos Antineoplásicos/farmacologia , Proteínas Reguladoras de Apoptose/metabolismo , Regulação para Baixo , Doxorrubicina/farmacologia , Resistencia a Medicamentos Antineoplásicos , Proteínas de Neoplasias/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Proteína Supressora de Tumor p53/antagonistas & inibidores , Animais , Antibióticos Antineoplásicos/administração & dosagem , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Modelos Animais de Doenças , Doxorrubicina/administração & dosagem , Transição Epitelial-Mesenquimal , Humanos , Imunoprecipitação , Camundongos Endogâmicos BALB C , Modelos Biológicos , Mapeamento de Interação de Proteínas , Técnicas do Sistema de Duplo-Híbrido
12.
Food Chem ; 249: 143-153, 2018 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-29407917

RESUMO

The use of coffee leaves as a novel beverage has recently received consumer interest, but there is little known about how processing methods affect the quality of final product. We applied tea (white, green, oolong and black tea) processing methods to process coffee leaves and then investigated their effects on phytochemical composition and related antioxidant and anti-inflammatory properties. Using Japanese-style green tea-processing of young leaves, and black tea-processing of mature (BTP-M) coffee leaves, produced contrasting effects on phenolic content, and associated antioxidant activity and nitric oxide (NO) inhibitory activity in IFN-γ and LPS induced Raw 264.7 cells. BTP-M coffee leaves also had significantly (P < .05) higher responses in NO, iNOS, COX-2, as well as a number of cytokines, in non-induced Raw 264.7. Our findings show that the age of coffee leaves and the type of processing method affect phytochemical profiles sufficiently to produce characteristic antioxidant and anti-inflammatory activities.


Assuntos
Coffea/química , Manipulação de Alimentos/métodos , Compostos Fitoquímicos/química , Extratos Vegetais/química , Folhas de Planta/química , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Camellia sinensis/química , Sobrevivência Celular/efeitos dos fármacos , Citocinas/imunologia , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Camundongos , Óxido Nítrico/imunologia , Fenóis/química , Fenóis/farmacologia , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/farmacologia , Células RAW 264.7 , Chá/química , Fatores de Tempo
13.
Food Chem ; 219: 428-435, 2017 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-27765248

RESUMO

The structure of the desalted duck egg white peptides-calcium chelate was characterized by fluorescence spectroscopy, fourier transform infrared spectroscopy, and dynamic light scattering. Characterization results showed structural folding and aggregation of amino acids or oligopeptides during the chelation process. Desalted duck egg white peptides enhanced the calcium uptake in the presence of oxalate, phosphate and zinc ions in Caco-2 monolayers. Animal model indicated that desalted duck egg white peptides effectively enhanced the mineral absorption and counteracted the deleterious effects of phytic acid. These findings suggested that desalted duck egg white peptides might promote calcium uptake in three pathways: 1) desalted duck egg white peptides bind with calcium to form soluble chelate and avoid precipitate; 2) the chelate is absorbed as small peptides by enterocyte; and 3) desalted duck egg white peptides regulate the proliferation and differentiation of enterocytes through the interaction with transient receptor potential vanilloid 6 calcium channel.


Assuntos
Cálcio/metabolismo , Clara de Ovo , Enterócitos/efeitos dos fármacos , Peptídeos/farmacologia , Ácido Fítico/farmacologia , Aminoácidos/metabolismo , Animais , Células CACO-2 , Patos , Enterócitos/metabolismo , Humanos , Peptídeos/metabolismo , Zinco/metabolismo
14.
J Sep Sci ; 39(21): 4234-4242, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27700004

RESUMO

In this study, peptides that facilitate alcohol metabolism were purified and identified from corn protein hydrolysates. The ultra-filtered fraction with a molecular weight < 3 kDa (F3) potential activity was separated into six fractions (F3-H1-F3-H6) by semi-preparative high-performance liquid chromatography. Among the resultant six fractions, F3-H4 and F3-H5 exhibited the highest ability to eliminate alcohol in vivo. A total of 16 peptides with strong signal values were identified from F3-H4 and F3-H5 fractions by nano liquid chromatography coupled with electrospray ionization tandem mass spectrometry. Several identified peptides were then selected and synthesized to determine their potential to facilitate alcohol metabolism. We found that Leu-Leu and Pro-Phe were the key structure units in Gln-Leu-Leu-Pro-Phe responsible for this peptide's ability to facilitate alcohol metabolism. However, the role of Leu-Leu and Pro-Phe may be affected by peptide chain length and hydrophobic properties. Our results have thus provided some insight into the study of the structure-activity relationships of corn peptides.


Assuntos
Álcoois/metabolismo , Proteínas de Plantas/química , Zea mays/química , Sequência de Aminoácidos , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Peptídeos/química , Espectrometria de Massas por Ionização por Electrospray , Relação Estrutura-Atividade , Espectrometria de Massas em Tandem
15.
Sci Rep ; 6: 32658, 2016 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-27596723

RESUMO

Potassium channel tetramerization domain containing 1 (KCTD1) family members have a BTB/POZ domain, which can facilitate protein-protein interactions involved in the regulation of different signaling pathways. KCTD proteins have potential Zn(2+)/Cu(2+) binding sites with currently unknown structural and functional roles. We investigated potential Cu(2+)-specific effects on KCTD1 using circular dichroism, turbidity measurement, fluorescent dye binding, proteinase K (PK) digestion, cell proliferation and apoptosis assays. These experiments indicate that the KCTD1 secondary structure assumes greater ß-sheet content and the proteins aggregate into a PK-resistant form under 20 µM Cu(2+), and this ß-sheet-rich aggregation with Cu(2+) promotes fibril formation, which results in increased cell toxicity by apoptosis. Our results reveal a novel role for Cu(2+) in determining the structure and function of KCTD1.


Assuntos
Cobre/metabolismo , Proteínas Repressoras/metabolismo , Sítios de Ligação , Linhagem Celular , Sobrevivência Celular , Dicroísmo Circular , Proteínas Correpressoras , Humanos , Microscopia Eletrônica de Transmissão , Estrutura Secundária de Proteína , Proteínas Repressoras/química , Espectrometria de Fluorescência
16.
J Food Drug Anal ; 24(1): 95-104, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28911415

RESUMO

Corn peptides (CPs) are reported to have many biological functions, such as facilitating alcohol metabolism, antioxidation, antitumor, antihypertension, and hepatoprotection. To develop a method for quality control, the high-performance liquid chromatography (HPLC) system was applied. Twenty-eight common peaks were found in all the CPs of corn samples from Enshi, China, based on which, a fingerprinting chromatogram was established for use in quality control in future research. Subsequently, the major chemical constituents of these common peaks were identified respectively using the HPLC-diode-array detection electrospray ionization tandem mass spectrometry (DAD-ESI-MS/MS) system, and 48 peptide fractions were determined ultimately. This was the first time for the majority of these peptides to be reported, and many of them contained amino acids of glutamine (Q), L and A, which might play an important role in the exhibition of the bioactivities of CPs. Many peptides had a similar primary structure to the peptides which had been proven to be bioactive such as facilitating alcohol metabolism, scavenging free radicals, and inhibiting lipid peroxidation. This systematical analysis of the primary structure of CPs facilitated subsequent studies on the relationship between the structures and functions, and could accelerate holistic research on CPs.

17.
J Agric Food Chem ; 63(37): 8170-6, 2015 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-26322960

RESUMO

The effects of desalted duck egg white peptides (DPs) on calcium absorption were investigated in three models: Caco-2 cell monolayer model, Caco-2 cell population model, and everted intestinal sac model. DPs were found to enhance calcium transport and may do so by acting as calcium carriers and interacting with the cell membrane to open a special Ca(2+) channel, whereas the paracellular pathway may make only a minor contribution. Structure characterization demonstrated the important roles of seven crucial peptides, such as VSEE and LYAEE, in binding calcium and promoting calcium uptake. Three synthetic peptides (VHSS, VSEE, and VHS(p)S(p)) potently induced calcium transport in Caco-2 monolayers, with VHS(p)S(p) being the most effective. This research expands the understanding of the mechanism of cellular calcium uptake by DPs as well as highlights an opportunity for recycling an otherwise discarded processing byproduct.


Assuntos
Cálcio/metabolismo , Cálcio/farmacocinética , Patos , Proteínas do Ovo/química , Proteínas do Ovo/farmacologia , Cloreto de Sódio , Animais , Células CACO-2 , Cálcio da Dieta/administração & dosagem , Membrana Celular , Manipulação de Alimentos/métodos , Humanos , Absorção Intestinal/efeitos dos fármacos , Reciclagem
18.
Int J Mol Sci ; 16(9): 22062-80, 2015 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-26378531

RESUMO

In this study, the effects of mixed corn peptides and synthetic pentapeptide (QLLPF) on hepatocyte apoptosis induced by ethanol were investigated in vivo. QLLPF, was previously characterized from corn protein hydrolysis, which had been shown to exert good facilitating alcohol metabolism activity. Mice were pre-treated with the mixed corn peptides and the pentapeptide for 1 week and then treated with ethanol. After treatment of three weeks, the biochemical indices and the key ethanol metabolizing enzymes, the serum TNF-α, liver TGF-ß1 concentrations and the protein expressions related to apoptosis were determined. We found that the Bcl-2, Bax and cytochrome c expressions in the intrinsic pathway and the Fas, FasL and NF-κB expressions in the extrinsic pathway together with higher TNF-α and TGF-ß1 concentrations were reversed compared with the model group by both the mixed corn peptides and the pentapeptide. The activation of caspase3 was also suppressed. Additionally, apoptosis was further confirmed with terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and the TUNEL assay demonstrated peptides suppressed hepatocyte apoptosis. Our results suggest that apoptosis induced by ethanol is alleviated in response to the treatment of corn peptides, potentially due to reversing the related protein expression.


Assuntos
Apoptose/efeitos dos fármacos , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Peptídeos/farmacologia , Extratos Vegetais/farmacologia , Zea mays/química , Animais , Peso Corporal/efeitos dos fármacos , Caspase 3/genética , Caspase 3/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , Doença Hepática Induzida por Substâncias e Drogas/genética , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/patologia , Citocinas/metabolismo , Modelos Animais de Doenças , Etanol/efeitos adversos , Etanol/metabolismo , Expressão Gênica/genética , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Testes de Função Hepática , Masculino , Redes e Vias Metabólicas/efeitos dos fármacos , Camundongos , Oxirredução/efeitos dos fármacos , Peptídeos/química , Extratos Vegetais/química , Transdução de Sinais/efeitos dos fármacos
19.
J Med Food ; 16(10): 912-9, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24063407

RESUMO

Certain bioactive peptides are reported to be able to alleviate hepatic fibrosis. Our previous work has confirmed the hepatoprotective effect of corn peptides (CPs) that are prepared from a high protein by-product, corn gluten meal, on acute liver injury in an animal model. However, the antifibrotic activity of CPs remained to be elucidated. In this study, the hepatoprotective effect of CPs on thioacetamide (TAA)-induced liver fibrosis was tested. Results showed that CPs (100 mg/kg body weight) significantly decreased the levels of alanine transaminase/aspartate transaminase, laminin, type IV collagen, and type III collagen in serum and increased the serum albumin levels and total antioxidant capacity. Additionally, with CP treatment (100 mg/kg body weight), a significant decrease was observed in the levels of malondialdehyde, nitric oxide, hydroxyproline, transforming growth factor ß1, and lactate dehydrogenase activity as well as the liver index, while the activity of superoxidedismutase was significantly increased in livers. The histological and morphological analysis showed that the hepatocyte structure in CP-treated rats was superior to that of TAA-injured rats, and inflammation and fibrosis were also ameliorated. Therefore, CPs can be used as an option for prevention and adjuvant therapy of liver fibrosis.


Assuntos
Cirrose Hepática/prevenção & controle , Peptídeos/administração & dosagem , Substâncias Protetoras/administração & dosagem , Zea mays/química , Animais , Antioxidantes/metabolismo , Humanos , Cirrose Hepática/induzido quimicamente , Cirrose Hepática/tratamento farmacológico , Cirrose Hepática/metabolismo , Testes de Função Hepática , Masculino , Malondialdeído/metabolismo , Mapeamento de Peptídeos , Peptídeos/química , Proteínas de Plantas/química , Ratos , Ratos Wistar , Tioacetamida/efeitos adversos , Fator de Crescimento Transformador beta1/metabolismo
20.
Food Chem Toxicol ; 51: 297-305, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23063592

RESUMO

This study was aimed at evaluating the anti-tumor mechanism of corn peptides (CPs). In vitro, the results showed that CPs significantly inhibited cell viability in both a dose- and a time-dependent manner. CPs treatment induced S cell-cycle arrest and caused apoptotic death in HepG2 cells. It was observed that CPs caused the increased in Bax/Bcl-2 ratio and triggered the activation of Cleaved-caspase-3, p53 in HepG2 cells. In vivo, the results showed that CPs could not only inhibit the growth of the tumor, but also enhance the spleen index, as well as the level of IL-2, IFN-γ and TNF-α. Moreover, CPs could prolong the survival time in H22-bearing mice. This study demonstrated that CPs was an apoptosis inducer in HepG2 cells, that it could effectively inhibit hepatocellular carcinoma in vivo via enhancement of host immune system function, and that it could be a safe and effective anticancer, bioactive agent or functional food.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Proteínas de Plantas/farmacologia , Zea mays/química , Animais , Apoptose/fisiologia , Caspase 3/metabolismo , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Células Hep G2/efeitos dos fármacos , Humanos , Interleucina-2/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Pontos de Checagem da Fase S do Ciclo Celular/efeitos dos fármacos , Baço/efeitos dos fármacos , Fator de Necrose Tumoral alfa/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...