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1.
Free Radic Biol Med ; 222: 467-477, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38969272

RESUMO

To investigate the effects of discharge plasma on Agropyron mongolicum seeds, various treatments including direct exposure to discharge plasma, combined treatment with discharge plasma and plasma-activated water (PAW) were applied to the seeds. The changes in germination rate, MDA content, and volatile compound levels of Agropyron mongolicum seeds after different treatments were examined. The results showed that the direct effect of plasma had no significant effect on the MDA content or germination rate of Agropyron mongolicum seeds due to the limited penetration depth. However, the combined effect of plasma and activated water could cause active nitrogen and oxygen particles to enter the seeds and cause oxidative stress damage. After 18 h of combined treatment, the MDA content increased significantly, and the germination rate decreased to below the semilethal dose, which was 33.44 %. After plasma treatment, 55 volatile compounds, mainly alcohols, aldehydes and ketones, were identified from the seeds of Agropyron mongolicum. Due to the oxidation and modification of the plasma, the content of most aldehydes increased with increasing reaction time. After screening, 13 volatile organic compounds could be used as potential markers to distinguish between different treatment methods. These results reveal the mechanism underlying the biological effects of plasma treatment on Agropyron mongolicum seeds.

2.
Food Chem X ; 21: 101104, 2024 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-38229670

RESUMO

The effects of deionized water thawing (DT), plasma-activated water thawing (PT), ultrasound (150 W, 40 kHz) combined with deionized water thawing (UDT), and ultrasound combined with plasma-activated water thawing (UPT) on the thawing characteristics and the physicochemical properties of the beef were investigated. The results showed that the UPT group had a faster thawing rate (38 % higher compared to the PT group) and good bactericidal ability (75 % higher compared to the UDT group), and had no adverse effect on the color and pH value of the beef. Plasma-activated water (PAW) can maintain the stability of the beef fiber, improve the water holding capacity (WHC), inhibit lipid oxidation, and reduce the loss of soluble substances such as protein. Therefore, UPT thawing is a promising meat thawing technology, which provides practical guidance and methods for the wide application of UPT in the field of meat thawing.

3.
IEEE Trans Biomed Eng ; 71(2): 504-513, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37616137

RESUMO

OBJECTIVE: Brain-computer interfaces (BCIs) have tremendous application potential in communication, mechatronic control and rehabilitation. However, existing BCI systems are bulky, expensive and require laborious preparation before use. This study proposes a practical and user-friendly BCI system without compromising performance. METHODS: A hybrid asynchronous BCI system was developed based on an elaborately designed wearable electroencephalography (EEG) amplifier that is compact, easy to use and offers a high signal-to-noise ratio (SNR). The wearable BCI system can detect P300 signals by processing EEG signals from three channels and operates asynchronously by integrating blink detection. RESULT: The wearable EEG amplifier obtains high quality EEG signals and introduces preprocessing capabilities to BCI systems. The wearable BCI system achieves an average accuracy of 94.03±4.65%, an average information transfer rate (ITR) of 31.42±7.39 bits/min and an average false-positive rate (FPR) of 1.78%. CONCLUSION: The experimental results demonstrate the feasibility and practicality of the developed wearable EEG amplifier and BCI system. SIGNIFICANCE: Wearable asynchronous BCI systems with fewer channels are possible, indicating that BCI applications can be transferred from the laboratory to real-world scenarios.


Assuntos
Interfaces Cérebro-Computador , Dispositivos Eletrônicos Vestíveis , Eletroculografia , Eletroencefalografia/métodos , Comunicação
4.
J Agric Food Chem ; 72(1): 351-362, 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38115585

RESUMO

Volatile terpenoids accumulate in citrus and play important roles in plant defense against various stressors. However, the broad-spectrum response of terpenoid biosynthesis to ubiquitous stressors in citrus has not been comparatively investigated. In this study, volatile terpenoids were profiled under six stressors: high temperature, citrus miner, citrus red mite, citrus canker, Alternaria brown spot, and huanglongbing (HLB). Significant content changes in 15 terpenoids, including ß-ocimene, were observed in more than four of the six stressors, implying their possibly universal stress-response effects. Notably, the emission of terpenoids, including ß-caryophyllene, ß-ocimene, and nerolidol glucoside, was significantly increased by HLB in HLB-tolerant "Shatian" pomelo leaves. The upregulation of CgTPS1 and CgTPS2 and their characterization in vivo identified them as mono- or sesquiterpenoid biosynthetic genes. This study provides a foundation for determining stress resistance mechanisms in citrus and biopesticide designations for future industrial applications.


Assuntos
Citrus , Citrus/genética , Terpenos , Monoterpenos Acíclicos , Perfilação da Expressão Gênica , Doenças das Plantas/prevenção & controle
5.
Food Chem X ; 20: 101026, 2023 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-38144751

RESUMO

The drying characteristics, rehydration capacity, color, infrared spectra and volatile components of iron stick yam slices were investigated under different alternating current (AC) voltages (13, 17, 21 kV), hot air drying (HAD) (60 °C) and natural drying (AD) by electrohydrodynamic (EHD) drying and HAD experimental devices. The results showed that slices of iron stick yam dried the quickest with HAD, which also had the fastest drying rate; while drying the slices of iron stick yam with EHD led to a better rehydration capacity, higher brightness L* and whiteness, a more stable protein secondary structure, and a greater variety and content of volatile components compared with AD and HAD. These finding indicated that EHD is a more promising method for drying iron stick yam.

6.
Food Chem X ; 19: 100818, 2023 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-37780274

RESUMO

Electrohydrodynamic (EHD) drying, natural air drying (AD) and hot air drying (HAD) were used to comprehensively study the drying characteristics and physicochemical properties of garlic, and low-field nuclear magnetic resonance (NMR), infrared spectroscopy, scanning electron microscopy and other technologies were used as detection methods. In terms of drying characteristics, HAD has the largest effective diffusion coefficient of moisture and the shortest average drying time. EHD-treated garlic slices had the most attractive color, the highest rehydration rate, the most stable cell structure, the highest content of active ingredients, and the most stable protein secondary structure. Therefore, electrohydrodynamic drying is a promising garlic slice drying technology and provides an effective method for the large-scale production of high-quality garlic.

7.
Free Radic Biol Med ; 182: 1-10, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35182731

RESUMO

To explore the effects of plasma-activated water (PAW) on gene expression, the combined treatment of PAW and discharge plasma on Astragalus adsurgens Pall seeds were performed, and then the gene expression of seedlings after treatmentwas analyzed at the molecular level. A needle array-plate dielectric-barrier discharge plasma was used to treat Astragalus adsurgens Pall seeds for 1, 2, and 3 h, and PAW was prepared at the same time to cultivate seeds. When the treatment time was 3 h, the survival rate of Plasma + PAW seedlings was only 9.2% of that of the CK. The Astragalus adsurgens Pall seedlings were analyzed using reactive oxygen species (ROS) and RNA-Seq. The ROS content of the seedlings in treatment group was significantly higher than that in the CK after 3 days of culture, that PAW cultivated can cause oxidative stress damage to Astragalus adsurgens Pall. The enzyme activity of the treated plant increased and the metabolic rate was accelerated. It helped to regulate the growth process of plants and improve the yield and quality of crops. This study discussed the gene expression of plasma and PAW induced Astragalus adsurgens Pall at the molecular level, and provided experimental data support for plasma and PAW treatment and selection of Astragalus adsurgens Pall.


Assuntos
Astrágalo , Água , Astrágalo/genética , Expressão Gênica , Plântula/genética
8.
Sensors (Basel) ; 21(16)2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34451056

RESUMO

Flood depth monitoring is crucial for flood warning systems and damage control, especially in the event of an urban flood. Existing gauge station data and remote sensing data still has limited spatial and temporal resolution and coverage. Therefore, to expand flood depth data source taking use of online image resources in an efficient manner, an automated, low-cost, and real-time working frame called FloodMask was developed to obtain flood depth from online images containing flooded traffic signs. The method was built on the deep learning framework of Mask R-CNN (regional convolutional neural network), trained by collected and manually annotated traffic sign images. Following further the proposed image processing frame, flood depth data were retrieved more efficiently than manual estimations. As the main results, the flood depth estimates from images (without any mirror reflection and other inference problems) have an average error of 0.11 m, when compared to human visual inspection measurements. This developed method can be further coupled with street CCTV cameras, social media photos, and on-board vehicle cameras to facilitate the development of a smart city with a prompt and efficient flood monitoring system. In future studies, distortion and mirror reflection should be tackled properly to increase the quality of the flood depth estimates.


Assuntos
Inundações , Redes Neurais de Computação , Humanos , Processamento de Imagem Assistida por Computador
9.
Int J Mol Med ; 48(3)2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34278451

RESUMO

Following the publication of this paper, it was drawn to the Editors' attention by a concerned reader that certain of the Transwell cell migration data shown in Figs. 2D and 4C were strikingly similar to data appearing in different form in other articles by different authors. Owing to the fact that the contentious data in the above article had already been published elsewhere, or were already under consideration for publication, prior to its submission to International Journal of Molecular Medicine, the Editor has decided that this paper should be retracted from the Journal. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive any reply. The Editor apologizes to the readership for any inconvenience caused. [the original article was published in International Journal of Molecular Medicine 38: 1587­1595, 2016; DOI: 10.3892/ijmm.2016.2754].

10.
Spectrochim Acta A Mol Biomol Spectrosc ; 236: 118350, 2020 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-32315952

RESUMO

In this study, corona discharge at atmospheric pressure under an alternating current (AC) field with a multi-needle plate electrode structure was used as mutagen to study the effects of corona discharge field on the hydrophilicity of alfalfa seeds, especially the effects of non-uniform electric field that is frequently ignored. Alfalfa seed were divided into two groups, one group was covered with 1 mm-thick polypropylene petri dish cover that can be approximated as a single factor effect of non-uniform electric field, the other group was directly irradiated by corona discharge field under different parameters. Fourier transform infrared spectroscopy (FTIR) and dual-index sequence analysis were used to detect and compare the spectra of alfalfa seed coats with different treatments. Results showed that the peaks of the seed coat at 2856 and 1727 cm-1 in the treatment group changed, indicating that hydrophobic wax, lipid, and cellulose may be cracked or degraded. Corona discharge field treatment can change the chemical structure of alfalfa seed coats, resulting in the changes in their hydrophilicity. The results of the apparent contact angle and scanning electron microscopy (SEM) and other experiments showed that the change in 19 kV non-covered treatment group was greatest, the petri dish cover can effectively reduce the physicochemical etching of ionic wind, the hydrophilicity of alfalfa seeds improved after corona discharge field treatment regardless of whether there is an ionic effect during irradiation, and the ionic wind has a greater influence on the hydrophilicity of alfalfa seeds than the non-uniform electric field. This study revealed the biological effect mechanism of corona discharge field from the perspective of spectral characteristics and provided experimental data support for the analysis of alfalfa seed surface modification and chemical structure after corona discharge field treatment.


Assuntos
Estimulação Elétrica/métodos , Medicago sativa/química , Sementes/química , Interações Hidrofóbicas e Hidrofílicas , Microscopia Eletrônica de Varredura , Gases em Plasma , Espectroscopia de Infravermelho com Transformada de Fourier , Água/química
11.
Foods ; 8(5)2019 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-31060330

RESUMO

In order to systematically and comprehensively investigate electrohydrodynamic (EHD) drying characteristics and mechanisms in a multiple needle-to-plate electrode system, drying experiments of Chinese wolfberry were conducted by blocking ionic wind and changing needle spacing in a multiple needle-to-plate electrode system. Drying characteristics, quality parameters, and the microstructure of Chinese wolfberry fruits were measured. Results show that ionic wind plays a very important role during the drying process. Drying rates of different needle spacing treatments are significantly higher than that of the control, and the drying rate decreases with the increase of needle spacing. Needle spacing has a great influence on the speed of ionic wind, rehydration rate, and polysaccharide contents. The effective moisture diffusion coefficient and the electrical conductivity disintegration index decreases with an increase in needle spacing. Ionic wind has a great influence on the effective moisture diffusion coefficient and the electrical conductivity disintegration index of Chinese wolfberry fruits. The microstructure of Chinese wolfberry fruits dried in an EHD system significantly changed. This study provides a theoretical basis and practical guidance for understanding characteristic parameters and mechanisms of EHD drying technology.

12.
ACS Appl Mater Interfaces ; 11(8): 8284-8290, 2019 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-30707841

RESUMO

Recently, flexible and wearable electronics are highly desirable because of their great potential in the next-generation information devices. In this work, we demonstrate the realization of the metal-insulator transition (MIT) effect in flexible rare-earth nickelate heterostructures. The NdNiO3 thin films are grown on lattice-mismatched mica substrates along the pseudocubic (111) direction via the van der Waals heteroepitaxy, in which the MIT behaviors are induced and modulated by carefully controlling the lattice strain and the ionic valence state with SrTiO3 and LaAlO3 buffering layers. Enhanced MIT properties with sharp transition and significant resistivity change between the metallic and the insulating states are achieved in the NdNiO3/LaAlO3/SrTiO3/mica heterostructures with appropriate in-plane tensile strain and suppressed concentration of Ni2+ ions. In addition, the proposed NdNiO3-based heterostructures exhibit excellent flexibility with reliable MIT characteristics not only in statically concave/convex bending but also in dynamically bending cycling up to 1000 times. The present work provides a platform to design and fabricate new flexible devices integrated with the MIT effect.

13.
J BUON ; 23(5): 1331-1336, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30570855

RESUMO

PURPOSE: To investigate the expression of thrombospondin 2 (THBS2) in colorectal cancer (CRC) and its relationship with clinicopathological features and prognosis. METHODS: THBS2 expression was evaluated with tissue microarrays (TMAs) immunohistochemistry (IHC) staining in 100 CRC samples. RESULTS: High THBS2 expression was found in 73 patients (45 male and 28 female). THBS2 expression was significantly correlated to TNM stages (p=4.1×10-5), T classification (p=0.005), lymph node metastasis (p=3×10-4) and AJCC stages (p=0), while no significant association was found in gender, age, distant metastasis or tumor size. In both univariate and multivariate analyses, THBS2 showed statistically prognostic significance [p<0.001, HR (hazard ratio) = 0.237, 95% CI (0.101-0.557) and p<0.001, HR=0.158, 95% CI (0.062-0.401)]. Kaplan-Meier survival analysis further confirmed that THBS2 expression was significantly correlated with clinical outcomes (p<0.001). CONCLUSIONS: All the results indicated THBS2 expression might become a prognostic marker for CRC.


Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias Colorretais/patologia , Trombospondinas/metabolismo , Idoso , Idoso de 80 Anos ou mais , Neoplasias Colorretais/metabolismo , Feminino , Seguimentos , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Taxa de Sobrevida
14.
Environ Manage ; 62(5): 968-986, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30069852

RESUMO

This study proposes a framework for evaluating anthropogenic nitrogen emissions and local vulnerability in order to assess regional ecological risk of human activity during a stable urbanization process. Taiwan, an isolated island with a unique environment, intensive agriculture, concentrated industries, and stable urbanization, was an ideal location for testing this framework. Local vulnerability is influenced by social characteristics, economic development, environmental protection, and other indicators related to these. Within the context of urbanization, therefore, and using official statistical data, human metabolism, agricultural and industrial production, and transportation were evaluated. The results indicate that the rate of anthropogenic nitrogen emissions decreased as the process of urbanization in Taiwan stabilized. While nitrogen emissions from agricultural production, household and industrial wastewater gradually decreased due to a reduction in the area of arable farmland, a reduction in the use of fertilizers and increased sewage treatment, nitrogen emissions from transportation increased due to higher energy consumption from vehicle use. Taiwan exhibited a higher degree of regional vulnerability in 1998 because motor vehicle density increased significantly, while rates of per capita green area and resource recovery remained relatively low. The study found that if Taiwan maintains its current conditions with respect to standard of living, agriculture, industry, and transportation, nitrogen emissions from human metabolism and agricultural and industrial production will not increase regional ecological risk, while nitrogen emissions from transportation will likely increase this risk. Therefore, this paper suggests that future environmental planning in Taiwan should prioritize low-emissions sustainable transportation.


Assuntos
Poluentes Atmosféricos/análise , Conservação dos Recursos Naturais/tendências , Nitrogênio/análise , Urbanização/tendências , Agricultura , Ecologia , Fertilizantes , Humanos , Indústrias , Veículos Automotores , Medição de Risco , Taiwan , Meios de Transporte
15.
Int J Mol Med ; 38(5): 1587-1595, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28026002

RESUMO

MicroRNAs (miRNAs or miRs) have been found to participate in the development and malignant progression of human cancers by negatively mediating the expression of their target genes. Recently, miR­33b has been reported to be involved in multiple types of human cancer, including hepatocellular carcinoma (HCC). However, the underlying regulatory mechanisms of miR­33b in HCC cell growth and metastasis remain largely unclear. In the present study, RT-qPCR revealed that miR­33b was significantly downregulated in HCC tissues compared to their matched adjacent normal tissues. Moreover, the miR­33b level was significantly lower in advanced-stage HCC (stages T3-T4) compared to early-stage HCC (stages T1-T2). Furthermore, it was also downregulated in the HCC cell lines, LH86, HepG2, LMH and PLHC-1, when compared with the THLE-3 normal human liver cells. We further demonstrated that the overexpression of miR­33b led to a significant decrease in the proliferation, migration and invasion of HepG2 and LH86 cells. Luciferase reporter assay identified Sal-like protein 4 (SALL4) as a target gene of miR­33b, and its protein expression was negatively regulated by miR­33b in HepG2 and LH86 cells. Moreover, the restoration of SALL4 expression markedly reversed the inhibitory effect of miR­33b overexpression on the proliferation, migration and invasion of HepG2 and LH86 cells, indicating that SALL4 is involved in miR­33b-mediated malignant phenotypes of HCC cells. Furthermore, we found that SALL4 was significantly upregulated in HCC tissues compared to their matched adjacent normal tissues, and its increased expression was significantly associated with the advanced malignancy of HCC. Moreover, SALL4 was also upregulated in HCC cell lines compared to the THLE-3 normal human liver cells. Finally, we found that the SALL4 expression inversely correlated with the miR­33b level in HCC tissues. On the whole, the findings of our study demonstrate that miR­33b suppresses the proliferation and metastasis of HCC cells through the inhibition of SALL4 expression. Therefore, miR­33b/SALL4 may become a potential therapeutic target for the treatment of HCC.


Assuntos
Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Regulação Neoplásica da Expressão Gênica , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , MicroRNAs/metabolismo , Fatores de Transcrição/genética , Adulto , Idoso , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Regulação para Baixo/genética , Feminino , Humanos , Masculino , MicroRNAs/genética , Pessoa de Meia-Idade , Invasividade Neoplásica , Metástase Neoplásica , Reação em Cadeia da Polimerase em Tempo Real , Software , Fatores de Transcrição/metabolismo , Transfecção
16.
PLoS One ; 10(4): e0124077, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25874695

RESUMO

Carrots have one of the highest levels of carotene, and they are rich in vitamins, fiber and minerals. However, since fresh carrots wilt rapidly after harvest under inappropriate storage conditions, drying has been used to improve their shelf life and retain nutritional quality. Therefore, to further investigate the potential of this method, carrot slices were dried in an EHD system in order to study the effect of different voltages on drying rate. As measures of quality, carotene content and rehydration ratio were, respectively, compared against the conventional oven drying regime. Carotene, the main component of the dried carrot, and rehydration characteristics of the dried product can both indicate quality by physical and chemical changes during the drying process. Mathematical modeling and simulation of drying curves were also performed, using root mean square error, reduced mean square of the deviation and modeling efficiency as the primary criteria to select the equation that best accounts for the variation in the drying curves of the dried samples. Theoretically, the Page model was best suited for describing the drying rate curve of carrot slices at 10kV to 30kV. Experimentally, the drying rate of carrots was notably greater in the EHD system when compared to control, and quality, as determined by carotene content and rehydration ratio, was also improved when compared to oven drying. Therefore, this work presents a facile and effective strategy for experimentally and theoretically determining the drying properties of carrots, and, as a result, it provides deeper insight into the industrial potential of the EHD drying technique.


Assuntos
Carotenoides/análise , Daucus carota/química , Dessecação/métodos , Modelos Estatísticos , Valor Nutritivo/fisiologia , Carotenoides/biossíntese , Simulação por Computador , Dessecação/instrumentação , Eletricidade , Humanos , Hidrodinâmica , Cinética , Minerais/análise , Água/química
17.
J Radiat Res ; 53(6): 854-9, 2012 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-23111758

RESUMO

Wild-type Escherichia coli K12 strain W3110 was irradiated by 10 keV nitrogen ions. Specifically, irradiation was performed six times by N(+) ions, followed by the selection of lac constitutive mutants, and each time a stable S55 mutant was produced. By sequencing the whole genome, the fine map of S55 was completed. Compared with reference sequences, a total of eighteen single nucleotide polymorphisms (SNPs), two insertions and deletions (Indels), and nine structural variations (SVs) were found in the S55 genome. Among the 18 SNPs, 11 are transversional from A, T or C to G, accounting for 55.6% of point mutations. GCCA insertion occurs in the target gene lacI. Four SNPs, including three in rlpB and one in ygbN, are connected with cell envelope and transport. All nine structural variations of S55 are deletions and contain insertion sequence (IS) elements. Six deleted SVs contain disrupted ISs, nonfunctional pseudogenes, and one more 23 252 bp SV in the Rac prophage region. Overall, our results show that deletion bias observed in E. coli K12 genome evolution is generally related to the deletion of some nonfunctional regions. Furthermore, since ISs are unstable factors in a genome, the multi-ion irradiations that caused these deleted fragments in S55 turn out to be beneficial to genome stability, generating a wider mutational spectrum. Thus, it is possible that the mutation of these genes increases the ability of the E. coli genome to resist etch and damage caused by ion irradiation.


Assuntos
Escherichia coli/genética , Escherichia coli/efeitos da radiação , Genoma Bacteriano/genética , Genoma Bacteriano/efeitos da radiação , Mutação Puntual/genética , Mutação Puntual/efeitos da radiação , Polimorfismo de Nucleotídeo Único/efeitos da radiação , Sequência de Bases/efeitos da radiação , Relação Dose-Resposta à Radiação , Íons Pesados , Dados de Sequência Molecular , Mutação/genética , Mutação/efeitos da radiação , Polimorfismo de Nucleotídeo Único/genética , Doses de Radiação
18.
J Lipid Res ; 52(12): 2272-2278, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21917726

RESUMO

Scavenger receptor BI (SR-BI) is an HDL receptor. It binds HDL and mediates the uptake of cholesteryl ester from HDL. Early studies have pointed out that the extracellular domain of SR-BI is critical for SR-BI-mediated cholesteryl ester uptake. However, the extracellular loop of SR-BI is large: it contains 403 amino acids. The HDL binding site and the modulation of SR-BI-mediated cholesteryl ester uptake remain to be identified. In this study, using C323G mutant SR-BI, we showed that C323G mutant SR-BI lost its HDL binding and cholesteryl ester uptake activity, indicating that the highly conserved C323 is required for SR-BI-mediated HDL binding and cholesteryl ester uptake. Using a blocking antibody against C323 region, we demonstrated that C323 is directly involved in HDL binding and likely an HDL binding site. Using C323G mutant transgenic mouse model, we further demonstrated that C323 of SR-BI is required for regulating plasma cholesterol levels in vivo. Using redox reagents, we showed that physiological relevant levels of H(2)O(2) upregulated the SR-BI-mediated cholesteryl ester uptake activity by 65%, whereas GSH or DTT significantly downregulated SR-BI-mediated cholesteryl ester uptake activity by 45%. C323 of SR-BI is critical for SR-BI-mediated HDL binding and cholesteryl ester uptake, and changes in redox status may be a regulatory factor modulating SR-BI-mediated cholesterol transport.


Assuntos
Ésteres do Colesterol/metabolismo , Cisteína , Lipoproteínas HDL/metabolismo , Receptores Depuradores Classe B/química , Receptores Depuradores Classe B/metabolismo , Animais , Células CHO , Cavéolas/metabolismo , Ésteres do Colesterol/sangue , Cricetinae , Cricetulus , Feminino , Humanos , Camundongos , Oxirredução , Ligação Proteica , Transporte Proteico
19.
J Biol Chem ; 285(33): 25154-60, 2010 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-20534584

RESUMO

Sepsis is a leading cause of death, which is characterized by uncontrolled inflammatory response. In this study, we report that caveolin-1, a major component of caveolae, is a critical survival factor of sepsis. We induced sepsis using a well established sepsis animal model, cecal ligation and puncture (CLP). CLP induced 67% fatality in caveolin-1 null mice, but only 27% fatality in wild type littermates (p = 0.015). Further studies revealed that mice deficient in caveolin-1 exhibited marked increase in tumor necrosis factor-alpha and interleukin-6 production 20 h following CLP treatment, indicating uncontrolled inflammatory responses in the absence of caveolin-1. Caveolin-1 null mice also had a significant increase in bacteria number recovered from liver and spleen, indicating elevated bacterial burdens. In addition, caveolin-1 null mice had a 2-fold increase in thymocyte apoptosis compared with wild type littermates, indicating caveolin-1 as a critical modulator of thymocyte apoptosis during sepsis. In conclusion, our findings demonstrate that caveolin-1 is a critical protective modulator of sepsis in mice. Caveolin-1 exerts its protective function likely through its roles in modulating inflammatory response, alleviating bacterial burdens, and suppressing thymocyte apoptosis.


Assuntos
Apoptose/imunologia , Caveolina 1/metabolismo , Sepse/imunologia , Sepse/microbiologia , Timo/citologia , Timo/imunologia , Animais , Apoptose/genética , Caveolina 1/genética , Citocinas/metabolismo , Modelos Animais de Doenças , Citometria de Fluxo , Perfuração Intestinal/complicações , Ligadura , Linfócitos/citologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Óxido Nítrico/metabolismo , Peroxidase/metabolismo , Punções , Sepse/etiologia
20.
Atherosclerosis ; 211(1): 90-5, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20189569

RESUMO

Serum amyloid P component (SAP) is a member of pentraxins. Previous studies indicate that SAP exists in human atherosclerotic aortic intima and the plasma SAP levels are associated with cardiovascular disease. In this study, we characterized SAP in normal and atherosclerotic intima, investigated the source of SAP in atherosclerotic lesions, and assessed the effect of SAP on HDL function. Immunohistochemical staining and electroimmunoassay indicated that SAP is not present in normal aortic intima which excludes the possibility that SAP non-specifically deposits in aortic intima via its binding to microfibrils. Notably, SAP levels are correlated with the severity of atherosclerotic lesions. Fast protein liquid chromatography (FPLC) and Western blot analysis revealed that SAP exists in atherosclerotic lesions in multiple forms. Soluble SAP accumulates in the lesions as decamer in free or bound forms via ligand-binding to its ligand(s). Insoluble SAP accumulates in the lesions in covalent-bound forms conjugated to collagen/collagen-like substances via disulfide (-S-S-) bonds. In situ hybridization and RT-PCR analysis revealed that SAP is generated in atherosclerotic lesions, at least partly, by macrophages and smooth muscle cells in neointima. Functional analysis demonstrated that SAP associated with HDL promotes SR-BI-dependent cholesterol efflux and lipid-free SAP enhances ABCA1-dependent cholesterol efflux. In conclusion, our findings demonstrate that SAP is specifically accumulated and expressed in atherosclerotic lesions. SAP may be involved in cholesterol clearance through its role in promoting cholesterol efflux.


Assuntos
Aterosclerose/metabolismo , Componente Amiloide P Sérico/metabolismo , Transportador 1 de Cassete de Ligação de ATP , Transportadores de Cassetes de Ligação de ATP/metabolismo , Aterosclerose/patologia , Células Cultivadas , Colesterol/metabolismo , Humanos , Lipoproteínas HDL/metabolismo , Receptores Depuradores Classe B/metabolismo , Componente Amiloide P Sérico/biossíntese , Túnica Íntima/metabolismo , Túnica Íntima/patologia
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