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Find video protocols related to scientific articles indexed in Pubmed.
3D-QSAR, molecular docking and molecular dynamics studies of a series of ROR?t inhibitors.
J. Biomol. Struct. Dyn.
PUBLISHED: 10-25-2014
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The discovery of clinically relevant inhibitors of retinoic acid receptor-related orphan receptor-gamma-t (ROR?t) for autoimmune diseases therapy has proven to be a challenging task. In the present work, to find out the structural features required for the inhibitory activity, we show for the first time a three-dimensional quantitative structure-activity relationship (3D-QSAR), molecular docking and molecular dynamics (MD) simulations for a series of novel thiazole/thiophene ketone amides with inhibitory activity at the ROR?t receptor. The optimum CoMFA and CoMSIA models, derived from ligand-based superimposition I, exhibit leave-one-out cross-validated correlation coefficient (R(2)cv) of .859 and .805, respectively. Furthermore, the external predictive abilities of the models were evaluated by a test set, producing the predicted correlation coefficient (R(2)pred) of .7317 and .7097, respectively. In addition, molecular docking analysis was applied to explore the binding modes between the inhibitors and the receptor. MD simulation and MM/PBSA method were also employed to study the stability and rationality of the derived conformations, and the binding free energies in detail. The QSAR models and the results of molecular docking, MD simulation, binding free energies corroborate well with each other and further provide insights regarding the development of novel ROR?t inhibitors with better activity.
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[Comparison of serum lipid and protein oxidation products levels in patients with different types of dyslipidemia].
Wei Sheng Yan Jiu
PUBLISHED: 09-10-2014
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To explore serum redox status differences among different types of dyslipidemia patients.
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Resveratrol preserves mitochondrial function, stimulates mitochondrial biogenesis, and attenuates oxidative stress in regulatory T cells of mice fed a high-fat diet.
J. Food Sci.
PUBLISHED: 08-23-2014
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Consumption of high-fat diet (HFD) is related with increased oxidative stress and dysfunctional mitochondria in many organs. The effects of resveratrol (trans-3,5,4'-trihydroxystilbene) that can protect T lymphocytes in various disease conditions on the HFD-induced apoptosis of CD4(+) CD25(+) CD127(low/-) regulatory T cells (Tregs) were studied, and the possible mechanism was postulated. Resveratrol significantly decreased Tregs death induced by 20-wk HFD, being associated with the reduction of reactive oxygen species production and the alleviation of HFD-induced loss of mitochondrial membrane potential (??m) in Tregs. Furthermore, resveratrol increased the expression of factors that regulated mitochondrial biogenesis in Tregs. Finally, resveratrol recovered the HFD-induced activation of apoptotic markers in Tregs. Resveratrol protected Tregs against HFD-induced apoptosis by reducing oxidative stress, restoring mitochondrial functional activities, and stimulating mitochondrial biogenesis.
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Regulatory effects of resveratrol on glucose metabolism and T-lymphocyte subsets in the development of high-fat diet-induced obesity in C57BL/6 mice.
Food Funct
PUBLISHED: 05-10-2014
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High-fat diet (HFD)-induced obesity is often associated with immune dysfunction. Resveratrol (trans-3,5,4'-trihydroxystilbene), which has well-founded immunity-related beneficial properties, was used to elucidate the regulatory effect on glucose metabolism and T-lymphocyte subsets in the development of HFD-induced obesity. Resveratrol, being associated with decreases of plasma leptin and plasma lipids and the release of oxidative stress, significantly decreased the body weight and fat masses in HF mice after 26 weeks of feeding. Furthermore, resveratrol decreased the fasting blood glucose and fasting plasma insulin and increased the CD3(+)CD4(+)/CD3(+)CD8(+) subsets percentages and the regulatory T cells (Tregs) production after 13 and 26 weeks of feeding. The results indicate that resveratrol, as an effective supplement for HFD, maintained glucose homeostasis by activating the PI3K and SIRT1 signaling pathways. Moreover, resveratrol activated the Nrf2 signaling pathway-mediated antioxidant enzyme expression to alleviate inflammation by protecting against oxidative damage and T-lymphocyte subset-related chronic inflammatory response in the development of HFD-induced obesity.
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Effects of resveratrol on gut microbiota and fat storage in a mouse model with high-fat-induced obesity.
Food Funct
PUBLISHED: 04-11-2014
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Recent studies have investigated the anti-obesity effect of resveratrol, but the pathways through which resveratrol resists obesity are not clear. In the present study, we hypothesize that resveratrol exerts anti-obesity effects that are likely mediated by mechanisms of regulating gut microbes, and in turn, improving fat storage and metabolism. Gut microbes, glucose and lipid metabolism in high-fat diet (HF) mice in vivo are investigated after resveratrol treatment. Several biochemical markers are measured. Fluorescence in situ hybridization and flow cytometry are used to monitor and quantify the changes in gut microbiota. The key genes related to fat storage and metabolism in the liver and visceral adipose tissues are measured by real-time PCR. The results show that resveratrol (200 mg per kg per day) significantly lowers both body and visceral adipose weights, and reduces blood glucose and lipid levels in HF mice. Resveratrol improves the gut microbiota dysbiosis induced by the HF diet, including increasing the Bacteroidetes-to-Firmicutes ratios, significantly inhibiting the growth of Enterococcus faecalis, and increasing the growth of Lactobacillus and Bifidobacterium. Furthermore, resveratrol significantly increases the fasting-induced adipose factor (Fiaf, a key gene negatively regulated by intestinal microbes) expression in the intestine. Resveratrol significantly decreases mRNA expression of Lpl, Scd1, Ppar-?, Acc1, and Fas related to fatty acids synthesis, adipogenesis and lipogenesis, which may be driven by increased Fiaf expression. The Pearson's correlation coefficient shows that there is a negative correlation between the body weight and the ratios of Bacteroidetes-to-Firmicutes. Therefore, resveratrol mediates the composition of gut microbes, and in turn, through the Fiaf signaling pathway, accelerates the development of obesity.
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A cell-penetrating peptide analogue, P7, exerts antimicrobial activity against Escherichia coli ATCC25922 via penetrating cell membrane and targeting intracellular DNA.
Food Chem
PUBLISHED: 04-09-2014
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The antibacterial activities and mechanism of a new P7 were investigated in this study. P7 showed antimicrobial activities against five harmful microorganisms which contaminate and spoil food (MIC=4-32 ?M). Flow cytometry and scanning electron microscopy analyses demonstrated that P7 induced pore-formation on the cell surface and led to morphological changes but did not lyse cell. Confocal fluorescence microscopic observations and flow cytometry analysis expressed that P7 could penetrate the Escherichia coli cell membrane and accumulate in the cytoplasm. Moreover, P7 possessed a strong DNA binding affinity. Further cell cycle analysis and change in gene expression analysis suggested that P7 induced a decreased expression in the genes involved in DNA replication. Up-regulated expression genes encoding DNA damage repair. This study suggests that P7 could be applied as a candidate for the development of new food preservatives as it exerts its antibacterial activities by penetrating cell membranes and targets intracellular DNA.
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Rapid microwave-assisted synthesis of polydextrose and identification of structure and function.
Carbohydr Polym
PUBLISHED: 03-12-2014
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Microwave irradiation is a rapid and efficient method to synthesize oligomers and can be employed in polysaccharides production. As an artificial polysaccharide, polydextrose is known for its solid performance in food processing and its additional health benefits. This study was aimed at producing polydextrose by microwave irradiation using glucose and sorbitol as substrates; water and phosphoric acid as initiator and catalyst. The actual maximum yield was 99%. Synthetic polydextrose were purified by ethanol elution and Sepherdex G-25 column chromatography. Its purity was demonstrated by the high-performance gel-permeation chromatography as a single symmetrical sharp peak, additionally the average molecular weight was calculated to be 2.131 kDa. FT-IR spectra showed that the synthesized polydextrose has the structural feature similar to Polydextrose-Litesse(®). In vitro fermentation revealed that polydextrose possesses the biological function similar to Polydextrose-Litesse(®) in increasing the concentration of short chain fatty acid and decreasing pH. This research demonstrated the feasibility of a rapid and efficient microwave mediated method to synthesize polydextrose and potentially other value added carbohydrate polymers.
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Propensity to high-fat diet-induced obesity in mice is associated with the indigenous opportunistic bacteria on the interior of Peyer's patches.
J Clin Biochem Nutr
PUBLISHED: 03-01-2014
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Indigenous opportunistic bacteria on the interior of the Peyer's patches play a key role in the development of the mucosal immune, but their population composition has been ignored. The present study was conducted to test the hypothesis that the changes in the composition of indigenous opportunistic bacteria in the Peyer's patches are associated with obesity. C57BL/6J-male mice had been fed either a control diet or a high-fat diet. After 25 weeks, mice in high-fat diet exhibit either an obesity-prone (OP) or an obesity-resistant (OR) phenotype. Control diet group (CT) and OR group had a significant larger bacteria diversity than that in the OP group. Allobaculum and Lactobacillus were significantly decreased in high-fat diet induced OP mice compared with CT and OR mice, whereas Rhizobium and Lactococcus was significantly increased. The result of quantitative real-time PCR was consistent with that of 454 pyrosequencing. Significant correlations between mRNA expression of inflammation marks and the top 5 abundance genera bacteria on the interior of Peyer's patches were observed by Pearson's correlation analysis. Taken together, the indigenous opportunistic bacteria on the interior of Peyer's patches plays a major role in the development of inflammation for an occurrence of obesity.
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Increased oxidative stress and the apoptosis of regulatory T cells in obese mice but not resistant mice in response to a high-fat diet.
Cell. Immunol.
PUBLISHED: 02-11-2014
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High fat feeding induces a variety of obese and lean phenotypes in inbred rodents. Obesity is a pro-inflammatory state, and regulatory T cells (Tregs) are essential negative regulators of inflammation. We aimed to determine the involvement of Tregs in the mice susceptible or resistant to high-fat diet (HFD). In the study, diet-induced obese (DIO) mice experienced significant increases in weight gain, energy intake, fat masses, plasma lipid and proinflammatory cytokines in comparison with control and diet-resistant (DR) mice. Also, Tregs production decreased in DIO mice. HFD diminished mitochondrial transmembrane potential (MTP) in the spleen Tregs of DIO mice and reinforced apoptosis compared with that in DR mice. Moreover, HFD significantly decreased antioxidant enzymes expressions and increased reactive oxygen species (ROS) productions in the Tregs of DIO mice, but not in those of DR mice, which should provide valuable evidence for unraveling the pathogenesis of inflammation found in this obese mice model.
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Evaluation of the relationship between subclinical hypothyroidism and metabolic syndrome components among workers.
Int J Occup Med Environ Health
PUBLISHED: 01-15-2014
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Both hyperthyroidism and overt hypothyroidism are associated with increased prevalence of metabolic syndrome and its components, while data on subclinical hypothyroidism is currently limited especially in working populations. The aim of this study was to examine the association between subclinical hypothyroidism and metabolic syndrome components in workers; and to evaluate whether there are differences by sex and occupation.
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[Antibacterial activity and mechanisms of a new peptide derived from cell-penetrating peptide].
Wei Sheng Wu Xue Bao
PUBLISHED: 12-31-2013
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We studied the antibacterial activities and mechanism of a new peptide P7, according to the structure-activity relationships of cell-penetrating peptide and antimicrobial peptide.
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Resveratrol prevents suppression of regulatory T-cell production, oxidative stress, and inflammation of mice prone or resistant to high-fat diet-induced obesity.
Nutr Res
PUBLISHED: 06-28-2013
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Consumption of a high-fat diet (HFD) is correlated with increased oxidative stress and chronic inflammation in many organs. Regulatory T cells (Tregs) are essential negative regulators of inflammation. We hypothesized that resveratrol (trans-3,5,4-trihydroxystilbene) could protect against HFD-induced oxidative stress and inflammation. Therefore, we examined the effect of resveratrol on oxidative stress and the relevant peripheral immune-regulating mechanisms in HFD-induced obese (DIO) and diet-resistant mice. C57BL/6 mice were fed a normal diet and an HFD for 13 weeks. Then the experimental group was subdivided into DIO and diet-resistant groups according to their body weights, which were further supplemented with 0.03% resveratrol and 0.06% resveratrol, respectively, for an additional 13 weeks. Resveratrol prevented the accumulation of chronic oxidative stress and suppression of Tregs production in HFD mice, modulated changes of cytokines in the plasma and spleen, and decreased expressions of inflammatory mediators compared with those of the DIO group. Our results indicate that resveratrol, as a feasible effective supplement for HFD, can relieve oxidative stress, inhibit inflammatory genes expression, and increase Tregs number via aryl hydrocarbon receptor activation inhibited by HFD, especially in DIO mice.
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Oxidized casein impairs antioxidant defense system and induces hepatic and renal injury in mice.
Food Chem. Toxicol.
PUBLISHED: 06-20-2013
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Oxidized protein products (OPPs) can be easily found in meat and milk during processing and storage. Evidence supports that accumulation of endogenous OPPs plays a negative role in physiological metabolism. However, the impacts of dietary OPPs and the mechanisms have not been elucidated yet. The present study evaluated whether oral oxidized casein would destruct the antioxidant defense system and cause potential oxidized injury in mice liver and kidney.
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Increased serum and urinary microRNAs in children with idiopathic nephrotic syndrome.
Clin. Chem.
PUBLISHED: 01-23-2013
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MicroRNAs (miRNAs) are present in body fluids and may have the potential to serve as disease biomarkers. This study explored the clinical value of miRNAs in serum and urine as biomarkers for idiopathic childhood nephrotic syndrome (NS).
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Structural and antioxidant modification of wheat peptides modified by the heat and lipid peroxidation product malondialdehyde.
J. Food Sci.
PUBLISHED: 12-19-2011
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Wheat peptides, the biological active peptides derived from foods, has an array of biological actions, including antiobesity, antimicrobial, and angiotensin I-converting enzyme inhibitory effects in mammalian species. Recent studies showed that some wheat peptides may show the noteworthy antioxidant potency against the peroxidation of lipids or fatty acids, but the effect of oxidation on its antioxidant activities is unclear. In the present study, we demonstrate that heat and malandialdehyde (MDA)-oxidized wheat peptides lose its surface hydrophobicity and reducing power, and show a relatively lower free radical-scavenging activitiy in vitro. Those modifications also lead to gradual formation of aggregates in wheat peptides and induce more reactive oxygen species (ROS) production in vivo. These findings indicate that oxidation may influence the functional properties and directly alter the structure of wheat peptides, and lead to the loss of its antioxidant potency both in vitro and in vivo, thereby providing a novel explanation for some of the potential health risks proposed for oxidized food in human.
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[Analysis of correlation between serum somatostatin levels, antioxidant index and metabolic syndrome].
Wei Sheng Yan Jiu
PUBLISHED: 08-25-2011
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To investigate serum somatostatin levels, antioxidant index in metabolic syndrome (MS).
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Lipoic acid increases the expression of genes involved in bone formation in mice fed a high-fat diet.
Nutr Res
PUBLISHED: 03-18-2011
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Antioxidant lipoic acid (LA) has been reported to have a potential prophylactic effect on bone loss induced by high-fat diet (HFD). The aim of this work was to examine the hypothesis that LA decreases bone resorption-related gene expression and increases bone formation-related gene expression in HFD-fed mice, preventing a shift in the bone metabolism balance toward resorption. Male C57BL/6 mice were fed a normal diet, HFD, or HFD plus 0.1% LA for 12 weeks. The bone metabolism-related genes differentially expressed between mice fed HFD and those fed HFD supplemented with LA were identified through complementary DNA microarray. The supplemental LA significantly increased bone mineral density and bone antioxidant capacity in mice fed HFD (P < .05). Compared with the HFD-fed mice, LA induced the decreased expression of genes associated with bone resorption, such as Mmp9 (1.9-fold) and Ctsk (2.3-fold), and increased those genes associated with bone formation, such as Col1a1 (1.3-fold) and Alp1 (1.5-fold). Furthermore, LA upregulated many genes involved in the Igf signaling pathway, such as Igf-1 (increased 1.7-fold), and downregulated genes involved in the p53 apoptotic pathway, such as p53 (decreased 2.3-fold), thus attenuating the HFD-induced inhibition of bone formation. Lipoic acid induced upregulation of Il12a (2.1-fold) and downregulation of Tgfbr1 (4.3-fold) and Il17a (11.3-fold), which may reduce bone resorption. In summary, LA supplementation during HFD could affect bone density, altering gene expression.
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Comparative in vivo antioxidant capacity of DL-2-hydroxy-4-methylthiobutanoic acid (HMTBA) and DL-methionine in male mice fed a high-fat diet.
J. Sci. Food Agric.
PUBLISHED: 01-05-2011
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In animal diets, methionine (Met) is considered to be the first limiting amino acid, and the activity of synthetic Met is typically added either as DL-methionine (DLM) or as DL-2-hydroxy-4-methylthiobutanoic acid (HMTBA). It has been demonstrated that HMTBA exhibits a higher antioxidant capability in vitro as compared to DLM. However, the difference in antioxidant capability between DLM and HMTBA in vivo is unknown.
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[The action mechanism of analogues of the antimicrobial peptide Buforin II with E. coli genomic DNA].
Wei Sheng Wu Xue Bao
PUBLISHED: 05-27-2010
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The aim was to study the action mechanism of analogues BF2-A/B of the antimicrobial peptide Buforin II with Escherichia coli (E. coli) genomic DNA.
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Comparative proteome analysis of splenic lymphocytes in long-term high-fat diet and dietary supplement with lipoic acid mice.
Cell. Immunol.
PUBLISHED: 01-10-2010
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The objective of this investigation was to explore possible molecular changes for role of a high-fat diet (HFD)-induced oxidative stress in splenic lymphocytes, and whether a dietary lipoic acid (LA) supplement could attenuate these changes. Male C57BL/6 mice were fed one of three diets 10 weeks and outcome measures centered on parameters of oxidative stress and lymphocytes apoptosis in spleen. Two-dimensional gel electrophoresis was used to compare the proteomes of splenic lymphocytes with three dietary groups. Differentially expressed spots whose expression altered over three fold were identified by MALDI-TOF MS. In this study, HFD resulted in oxidative stress in mice spleen, and significantly increased apoptotic percentage of splenic lymphocytes. Bioinformatic evaluation results of MALDI-TOF MS showed that 20 differentially expressed protein spots were known to be involved in many processes associated with cell function, such as cytoskeleton, energy metabolism and oxidative stress, signal transduction and cell defense. In conclusion, these results indicate that HFD-induced oxidative stress could lead to the functional decline of splenic lymphocytes, and LA supplement attenuates the alterations of protein expression to maintain the basic biological processes.
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[Immune modulation and antioxidant effects of wheat peptide on immunosuppressed mice].
Sheng Wu Gong Cheng Xue Bao
PUBLISHED: 07-30-2009
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We studied immune modulation and antioxidant effects of wheat peptides on immunosuppressed mice. Mice were administrated with wheat peptides orally for 10 days and treated with cyclophosphamide at the 8th day. The indexes including serum hemolysin, plaque forming cells, spleen cells proliferation, liver antioxidant enzymes activties, malondialdehyde (MDA), scavenging serum 2,2-Diphenyl-1-picrylhydrazyl and *OH and macrophage phagocytic ability in vitro were measured to assess the immune functions and antioxidation abilities. In vivo study shows that cyclophosphamide significantly decreases serum hemolysin (HC50) and phagocytic function of macrophages. Simultaneously, liver superoxide dismutase, catalase activity and total oxidation capacity were decreased and malondialdehyde was increased. Wheat peptides could recover HC50 and spleen cell proliferation when orally administrated. Furthermore, they could also enhance serum 2,2-Diphenyl-1-picrylhydrazyl and *OH scavenging. In conclusion, wheat peptides can help body resist the stress related disorders in immune and antioxidant system.
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Lipoic acid attenuates high fat diet-induced chronic oxidative stress and immunosuppression in mice jejunum: a microarray analysis.
Cell. Immunol.
PUBLISHED: 05-18-2009
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A high fat diet (HFD) has long been linked to immune dysfunction, including diminished numbers or reactivity of lymphocytes, increased susceptibility to infection, inhibited lymphocytes function during antigen-specific responses and developed oxidative stress. Whereas the molecular mechanistic events associated with immune deficiency remain to be fully determined. Using the DNA microarray system, we analyzed the gene expression patterns of lymphocyte related signal transduction proteins in jejunum of C57BL/6 mice in order to gain insight on the possible molecular mechanism by which HFD induced oxidative stress effects on signal transduction of lymphocytes. Results of present study showed that HFD induced oxidative stress and immunosuppression in jejunum. Antioxidant lipoic acid (LA) supplement ameliorated that HFD induced oxidative stress and immunosuppression by recovering transcriptional levels of the gene involved in B cell receptor, T cell differentiation signaling pathway, and free radical scavengers. The present study indicates that a HFD can induce chronic oxidative stress, suppress signal transduction of gut-associated lymphocytes, and lead to an inhibition of mucosal immunity.
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Effects of Lactobacillus plant arum on genes expression pattern in mice jejunal Peyers patches.
Cell. Immunol.
PUBLISHED: 02-19-2009
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Jejunal Peyers patches contain specialized epithelial M cells that take up ingested microorganisms from the lumen of the gut by transcytosis. Using DNA-micro array, we analyzed the gene expression patterns of jejunal Peyers patches in order to gain insight into the molecular mechanism by which Lp6 interacted with the host organism in a gnotobiotic environment v. in the gut normal microflora. The micro array data revealed that, among approximately 14,000 genes, 420 were expressed in Lp6 administration group at twofold or higher levels compared to the control group. These included genes involved in immune response, and cell differentiation, cell-cell signaling, cell adhesion, signal transcription, and transduction. Real-time PCR confirmed the reliability of the analysis. These data indicated that administration of Lactobacillus Lp6 was associated with a complex genetic response in the jejunal Peyers patches.
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Alterations of the gut microbiota in high-fat diet mice is strongly linked to oxidative stress.
Appl. Microbiol. Biotechnol.
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Alterations of the gut microbiota induced by diet exert a strong influence on the development of metabolic syndrome. In this study, we prove the hypothesis that the long-term high-fat diet (HFD) may influence gut microbiota directly and/or indirectly by changing the redox state. Lipoic acid (LA), as a universal antioxidant, was used to improve the redox state. Reactive oxygen species (ROS), total antioxidant capacity (T-AOC), and malondialdehyde (MDA) were analyzed to profile oxidative stress states. PCR-denaturing gradient gel electrophoresis (DGGE) was used to describe gut flora structures, while plate count was employed for the quantitative analysis of Escherichia coli, lactobacilli, and enterococcus. The influence of redox state on the vitality of gut-derived bacteria was measured in vitro. ROS and MDA, which significantly decreased in LA mice compared with HFD mice, showed a strong positive association with E. coli and enterococcus (P?
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Antibacterial activity and dual mechanisms of peptide analog derived from cell-penetrating peptide against Salmonella typhimurium and Streptococcus pyogenes.
Appl. Microbiol. Biotechnol.
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A number of research have proven that antimicrobial peptides are of greatest potential as a new class of antibiotics. Antimicrobial peptides and cell-penetrating peptides share some similar structure characteristics. In our study, a new peptide analog, APP (GLARALTRLLRQLTRQLTRA) from the cell-penetrating peptide ppTG20 (GLFRALLRLLRSLWRLLLRA), was identified simultaneously with the antibacterial mechanism of APP against Salmonella typhimurium and Streptococcus pyogenes. APP displayed potent antibacterial activity against Gram-negative and Gram-positive strains. The minimum inhibitory concentration was in the range of 2 to 4 ?M. APP displayed higher cell selectivity (about 42-fold increase) as compared to the parent peptide for it decreased hemolytic activity and increased antimicrobial activity. The calcein leakage from egg yolk L-?-phosphatidylcholine (EYPC)/egg yolk L-?-phosphatidyl-DL-glycerol and EYPC/cholesterol vesicles demonstrated that APP exhibited high selectivity. The antibacterial mechanism analysis indicated that APP induced membrane permeabilization in a kinetic manner for membrane lesions allowing O-nitrophenyl-?-D-galactoside uptake into cells and potassium release from APP-treated cells. Flow cytometry analysis demonstrated that APP induced bacterial live cell membrane damage. Circular dichroism, fluorescence spectra, and gel retardation analysis confirmed that APP interacted with DNA and intercalated into the DNA base pairs after penetrating the cell membrane. Cell cycle assay showed that APP affected DNA synthesis in the cell. Our results suggested that peptides derived from the cell-penetrating peptide have the potential for antimicrobial agent development, and APP exerts its antibacterial activity by damaging bacterial cell membranes and binding to bacterial DNA to inhibit cellular functions, ultimately leading to cell death.
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Effects of heat treatment on structural modification and in vivo antioxidant capacity of soy protein.
Nutrition
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The present study identified the effects of heat oxidation on protein carbonyl content and ?,?-diphenyl-?-picrylhydrazyl (DPPH) free radical-scavenging activity in soy protein. The changes on antioxidant status in male mice fed a heat-oxidized diet were also investigated.
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Selectivity for and destruction of Salmonella typhimurium via a membrane damage mechanism of a cell-penetrating peptide ppTG20 analogue.
Int. J. Antimicrob. Agents
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P7, an analogue of the cell-penetrating peptide (CPP) ppTG20, was derived by replacing Phe and Trp with Arg based on the structure-activity relationships of CPPs and antimicrobial peptides (AMPs). P7 showed antimicrobial activity against Salmonella typhimurium at 4 ?M and possessed broad antimicrobial activity greater than its parent peptide. P7 displayed good selectivity, with low haemolysis below its minimum inhibitory concentration range, but displayed cytotoxic activity against the HT29 and MDA-MB231 mammalian cell lines. Studies of calcein leakage from egg yolk L-?-phosphatidylcholine/egg yolk L-?-phosphatidyl-DL-glycerol (EYPC/EYPG) (bacterial membrane mimic) and EYPC/cholesterol (eukaryotic membrane mimic) vesicles also demonstrated that P7 exhibited high selectivity and caused pore formation in the bacterial membrane. Circular dichroism experiments suggested that the conformation of P7 underwent transitions from a random coil in sodium phosphate buffer to an ?-helical conformation in bacterial model membranes. P7 induced influx of the membrane fluorescent probe 1-N-phenylnaphthylamine (NPN) and the nucleic acid fluorescent probe SYTOX(®) Green by increasing live S. typhimurium cell outer membrane and plasma membrane permeability, respectively. P7 also induced ion channel formation in the cell plasma membrane causing leakage of potassium ions. Flow cytometric analysis demonstrated that S. typhimurium cell membrane integrity was destroyed following incubation with P7. These results indicated that P7 exhibited good bacterial selectivity and exerted its antibacterial activity by a membrane damage mechanism. Furthermore, these results suggested that CPPs may represent a source of templates for AMP design.
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High-fat diets impair spatial learning of mice in the Y-maze paradigm: ameliorative potential of ?-lipoic acid.
J Med Food
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High-fat diets (HFDs) have been found to influence central nervous system development and to cause cognitive impairments in human epidemiologic studies, as well as in animal investigations. These adverse effects on learning and memory induced by an HFD have been associated with an impaired hippocampus, including hippocampal oxidative damage. Previously, we had found that ?-lipoic acid (?-LA) could ameliorate the oxidative stress in non-neural organs (liver, jejunum, and spleen) induced by a 10-week HFD (21.2% fat) food regimen in mice. In this study, we investigated whether a 10-week HFD (21.2% fat) induced oxidative stress in the hippocampus or impaired spatial learning in mice and whether LA ameliorated these effects. The HFD was found to induce oxidative stress (a decrease in catalase activity, glutathione peroxidase activity, and total antioxidative capacity and an increase in malondialdehyde levels) in the mouse hippocampus. In addition, we found that the HFD impaired spatial recognition memory of mice in the Y-maze paradigm. Furthermore, the hippocampal oxidative stress and impaired spatial recognition memory of the mice were reduced in HFD diets supplemented with 0.1% LA. These findings suggest that LA, as a strong antioxidant, may help prevent HFD-induced learning impairments by ameliorating associated oxidative stress in the hippocampus.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.