DSpace Collection:
http://hdl.handle.net/2115/76083
2024-03-29T05:57:34ZA Basic Study of the Effects of Mulberry Leaf Administration to Mice on Gut Microbiota and Metabolites
http://hdl.handle.net/2115/91221
Title: A Basic Study of the Effects of Mulberry Leaf Administration to Mice on Gut Microbiota and Metabolites
Authors: 甘, 莉
Abstract: Mulberry leaves containα glucosidase inhibitors, which have hypoglycemic effects and are considered functional foods. However, few reports have covered the effects of mulberry leaf components on normal gut microbiota and gut metabolites. Herein, gut microbiota analysis and NMR based metabolomics were performed on the feces of mulberry leaf powder (MLP) treated mice to determine the effects of long term MLP consumption. Gut microbiota in the mouse were analyzed using 16S rRNA gene sequencing, and no significant differences were revealed in the diversity and community structure of the gut microbiota in the C57BL/6 mice with or without MLP supplementation. Thirty nine metabolites were identified via 1 H NMR analysis, and carbohydrates and amino acids were significantly ( p < 0.01 0.05) altered upon MLP treatment. In the MLP treated group, there was a marked increase and decrease in maltose and glucose concentrations, respectively, possibly due to the degradation inhibitory activity of oligosaccharides. After 5 weeks, all ami no acid concentrations decreased. Furthermore, despite clear fluctuations in fecal saccharide concentrations, short chain fatty acid production via intestinal bacterial metabolism was not strongly affected. This study provides the knowledge that MLP administration can alter the gut metabolites without affecting the normal gut microbiota, which is useful for considering MLP as a healthy food source.2023-12-24T15:00:00Z甘, 莉Mulberry leaves containα glucosidase inhibitors, which have hypoglycemic effects and are considered functional foods. However, few reports have covered the effects of mulberry leaf components on normal gut microbiota and gut metabolites. Herein, gut microbiota analysis and NMR based metabolomics were performed on the feces of mulberry leaf powder (MLP) treated mice to determine the effects of long term MLP consumption. Gut microbiota in the mouse were analyzed using 16S rRNA gene sequencing, and no significant differences were revealed in the diversity and community structure of the gut microbiota in the C57BL/6 mice with or without MLP supplementation. Thirty nine metabolites were identified via 1 H NMR analysis, and carbohydrates and amino acids were significantly ( p < 0.01 0.05) altered upon MLP treatment. In the MLP treated group, there was a marked increase and decrease in maltose and glucose concentrations, respectively, possibly due to the degradation inhibitory activity of oligosaccharides. After 5 weeks, all ami no acid concentrations decreased. Furthermore, despite clear fluctuations in fecal saccharide concentrations, short chain fatty acid production via intestinal bacterial metabolism was not strongly affected. This study provides the knowledge that MLP administration can alter the gut metabolites without affecting the normal gut microbiota, which is useful for considering MLP as a healthy food source.A Basic Study of the Effects of Mulberry Leaf Administration to Mice on Gut Microbiota and Metabolites [an abstract of dissertation and a summary of dissertation review]
http://hdl.handle.net/2115/91220
Title: A Basic Study of the Effects of Mulberry Leaf Administration to Mice on Gut Microbiota and Metabolites [an abstract of dissertation and a summary of dissertation review]
Authors: 甘, 莉2023-12-24T15:00:00Z甘, 莉Antimicrobial Properties and Mode of Action of Cryptdin-4, a Mouse α-Defensin Regulated by Peptide Redox Structures and Bacterial Cultivation Conditions
http://hdl.handle.net/2115/90805
Title: Antimicrobial Properties and Mode of Action of Cryptdin-4, a Mouse α-Defensin Regulated by Peptide Redox Structures and Bacterial Cultivation Conditions
Authors: 王, 一
Abstract: Cryptdin-4 (crp4) is an enteric α-defensin derived from mice that is a main mediator of immunity to oral infections and a determinant of the composition of the intestinal microbiota. Structurally, crp4 exists in two states: the oxidized form (crp4oxi), constrained by three invariant disulfide bonds, and the reduced form (crp4red) with six free thiol groups, both of which exist in the intestinal tract. In this study, the antibacterial mechanisms of crp4 in both forms under aerobic and anaerobic conditions were investigated using Escherichia coli (E. coli), an anaerobic facultative bacterium, as a model. Fluorescent dye studies revealed that both crp4oxi and crp4red exhibited antimicrobial activity against cells cultured under aerobic conditions via rapid membrane depolarization. Furthermore, the antioxidant treatment experiments suggested that only crp4oxi exhibited antimicrobial activity by the induction and accumulation of reactive oxygen species (ROS). However, under anaerobic culture conditions, the ability of both forms to disrupt the function of bacterial membranes decreased, and activity was greatly reduced, but crp4red maintained some antimicrobial activity. This activity may be due to the inhibition of intracellular functions by DNA binding. Altogether, these data indicate that, according to its redox structure and the environmental redox conditions, crp4 could perform different antimicrobial activities via different mechanisms.2023-09-24T15:00:00Z王, 一Cryptdin-4 (crp4) is an enteric α-defensin derived from mice that is a main mediator of immunity to oral infections and a determinant of the composition of the intestinal microbiota. Structurally, crp4 exists in two states: the oxidized form (crp4oxi), constrained by three invariant disulfide bonds, and the reduced form (crp4red) with six free thiol groups, both of which exist in the intestinal tract. In this study, the antibacterial mechanisms of crp4 in both forms under aerobic and anaerobic conditions were investigated using Escherichia coli (E. coli), an anaerobic facultative bacterium, as a model. Fluorescent dye studies revealed that both crp4oxi and crp4red exhibited antimicrobial activity against cells cultured under aerobic conditions via rapid membrane depolarization. Furthermore, the antioxidant treatment experiments suggested that only crp4oxi exhibited antimicrobial activity by the induction and accumulation of reactive oxygen species (ROS). However, under anaerobic culture conditions, the ability of both forms to disrupt the function of bacterial membranes decreased, and activity was greatly reduced, but crp4red maintained some antimicrobial activity. This activity may be due to the inhibition of intracellular functions by DNA binding. Altogether, these data indicate that, according to its redox structure and the environmental redox conditions, crp4 could perform different antimicrobial activities via different mechanisms.Antimicrobial Properties and Mode of Action of Cryptdin-4, a Mouse α-Defensin Regulated by Peptide Redox Structures and Bacterial Cultivation Conditions [an abstract of dissertation and a summary of dissertation review]
http://hdl.handle.net/2115/90804
Title: Antimicrobial Properties and Mode of Action of Cryptdin-4, a Mouse α-Defensin Regulated by Peptide Redox Structures and Bacterial Cultivation Conditions [an abstract of dissertation and a summary of dissertation review]
Authors: 王, 一2023-09-24T15:00:00Z王, 一Application of Benchtop NMR for Metabolomics Study Using Feces of Mice with DSS-Induced Colitis
http://hdl.handle.net/2115/90803
Title: Application of Benchtop NMR for Metabolomics Study Using Feces of Mice with DSS-Induced Colitis
Authors: 宋, 子豪
Abstract: Metabolomics aims to comprehensively measure the metabolites, which are the downstream product of genes, transcripts, and protein functions. It has been applied to identify key biomarkers and investigate the pathogenesis of various human diseases. High-field NMR spectrometer based on the superconducting magnet has been one of the most routinely used techniques for metabolomics studies owing to its inherent advantages of being non-destructive, requiring a short analysis time and little sample preparation. However, further applications for medical purposes and field research are restricted and far from routine utilization because of its large size, substantial investment, and requirement of cryogenic fluids maintenance and well-trained staff. The newly developed cryogen-free, low-field, benchtop NMR based on compact permanent magnets offer a potential solution to these challenges and may represent a new approach for metabolomics studies, benefiting from its small size and low running cost. In previous studies, the metabolic signature of type 2 diabetes has been profiled using urine samples. Moreover, tuberculosis in both humans and bovines was differentiated by benchtop NMR-based metabolomic fingerprinting using urine and plasma. Nevertheless, the feasibility of benchtop NMR for metabolomics studies has not been universally verified and the shortcomings of low sensitivity and resolution need to be solved. Therefore, to demonstrate the feasibility of benchtop NMR for fecal metabolomics, I employed the low-field NMR (60 MHz) to characterize the metabolic profile of feces samples from dextran sodium sulfate (DSS)-induced colitis mice, a commonly used model for inflammatory bowel diseases (IBD). I compared the results obtained from the benchtop NMR with those acquired using high-field superconducting NMR (800 MHz). In this study, six male C57BL/6JJcl mice were divided into the control group and DSS-induced group and cultivated for 7 days. The same diet was given to all mice while 3.5% of DSS was added into the drinking water for DSS group mice to induce colitis. The feces sample were collected each day for measurement by both 800 MHz and 60 MHz NMR spectrometers. Forty-one metabolites were identified in a representative 800 MHz 1H NMR spectra of concentrated fecal extracts from a healthy mouse. By referring to the assignment of 800 MHz spectra, nineteen metabolites were annotated to the 60 MHz spectra, including amino acids, short-chain fatty acids (SCFAs), creatine, formate, glucose, glycerol and lactate. To determine whether the metabolomics analysis based on 60 MHz NMR spectra performed effectively to discriminate the control group and DSS-induced group and provided comparable results with 800 MHz, multivariate analysis was performed for both 60 MHz and 800 MHz data. The analysis of 60 MHz data revealed that the metabolic signature of the DSS group began to separate from the control group from day 2 and completely separated from day 3, which showed the same trend with the 800 MHz data. A higher intensity of 1.9 ppm derived from the acetate has been characterized as the most important feature in the NMR spectra acquired from the of DSS-induced mice. The high concentration of the acetate compared with the other metabolites and its singlet peak facilitated its easy detection. Thus, I expected to quantify the concentration of acetate as a key biomarker in our model to discriminate between the two groups and substantiate the potential of 60 MHz benchtop NMR for further quantification analysis. Three methods were attempted to quantify the acetate in the pure sample and feces sample: 1) simple integration; 2) “Generalized Lorentzian” (GL) curve fitting and 3) curve fitting using an in-house prepared database. Three methods showed good linearity and reproducibility for quantifying the pure sample. On the other hand, the simple integration method showed a large difference with the reference concentration based on the routine method using 800 MHz data. In contrast, no significant error was found between low-field and high-field data using the curve fitting methods, suggesting their high accuracy. Consistent with 800 MHz data, the quantification of the 60 MHz NMR spectra demonstrated a significantly higher concentration of acetate in the DSS group at day 5. In summary, this study presented the potential applications of low-field benchtop NMR for the rapid diagnosis of IBD using a DSS-induced mouse model. The metabolic profile characterized by 60 MHz data showed good comparability with the 800 MHz data. In addition, the concentration of acetate, identified as a metabolite with characteristic behavior, could be accurately quantified using a “Generalized Lorentzian” curve fitting method based on the 60 MHz NMR spectra.2023-09-24T15:00:00Z宋, 子豪Metabolomics aims to comprehensively measure the metabolites, which are the downstream product of genes, transcripts, and protein functions. It has been applied to identify key biomarkers and investigate the pathogenesis of various human diseases. High-field NMR spectrometer based on the superconducting magnet has been one of the most routinely used techniques for metabolomics studies owing to its inherent advantages of being non-destructive, requiring a short analysis time and little sample preparation. However, further applications for medical purposes and field research are restricted and far from routine utilization because of its large size, substantial investment, and requirement of cryogenic fluids maintenance and well-trained staff. The newly developed cryogen-free, low-field, benchtop NMR based on compact permanent magnets offer a potential solution to these challenges and may represent a new approach for metabolomics studies, benefiting from its small size and low running cost. In previous studies, the metabolic signature of type 2 diabetes has been profiled using urine samples. Moreover, tuberculosis in both humans and bovines was differentiated by benchtop NMR-based metabolomic fingerprinting using urine and plasma. Nevertheless, the feasibility of benchtop NMR for metabolomics studies has not been universally verified and the shortcomings of low sensitivity and resolution need to be solved. Therefore, to demonstrate the feasibility of benchtop NMR for fecal metabolomics, I employed the low-field NMR (60 MHz) to characterize the metabolic profile of feces samples from dextran sodium sulfate (DSS)-induced colitis mice, a commonly used model for inflammatory bowel diseases (IBD). I compared the results obtained from the benchtop NMR with those acquired using high-field superconducting NMR (800 MHz). In this study, six male C57BL/6JJcl mice were divided into the control group and DSS-induced group and cultivated for 7 days. The same diet was given to all mice while 3.5% of DSS was added into the drinking water for DSS group mice to induce colitis. The feces sample were collected each day for measurement by both 800 MHz and 60 MHz NMR spectrometers. Forty-one metabolites were identified in a representative 800 MHz 1H NMR spectra of concentrated fecal extracts from a healthy mouse. By referring to the assignment of 800 MHz spectra, nineteen metabolites were annotated to the 60 MHz spectra, including amino acids, short-chain fatty acids (SCFAs), creatine, formate, glucose, glycerol and lactate. To determine whether the metabolomics analysis based on 60 MHz NMR spectra performed effectively to discriminate the control group and DSS-induced group and provided comparable results with 800 MHz, multivariate analysis was performed for both 60 MHz and 800 MHz data. The analysis of 60 MHz data revealed that the metabolic signature of the DSS group began to separate from the control group from day 2 and completely separated from day 3, which showed the same trend with the 800 MHz data. A higher intensity of 1.9 ppm derived from the acetate has been characterized as the most important feature in the NMR spectra acquired from the of DSS-induced mice. The high concentration of the acetate compared with the other metabolites and its singlet peak facilitated its easy detection. Thus, I expected to quantify the concentration of acetate as a key biomarker in our model to discriminate between the two groups and substantiate the potential of 60 MHz benchtop NMR for further quantification analysis. Three methods were attempted to quantify the acetate in the pure sample and feces sample: 1) simple integration; 2) “Generalized Lorentzian” (GL) curve fitting and 3) curve fitting using an in-house prepared database. Three methods showed good linearity and reproducibility for quantifying the pure sample. On the other hand, the simple integration method showed a large difference with the reference concentration based on the routine method using 800 MHz data. In contrast, no significant error was found between low-field and high-field data using the curve fitting methods, suggesting their high accuracy. Consistent with 800 MHz data, the quantification of the 60 MHz NMR spectra demonstrated a significantly higher concentration of acetate in the DSS group at day 5. In summary, this study presented the potential applications of low-field benchtop NMR for the rapid diagnosis of IBD using a DSS-induced mouse model. The metabolic profile characterized by 60 MHz data showed good comparability with the 800 MHz data. In addition, the concentration of acetate, identified as a metabolite with characteristic behavior, could be accurately quantified using a “Generalized Lorentzian” curve fitting method based on the 60 MHz NMR spectra.Application of Benchtop NMR for Metabolomics Study Using Feces of Mice with DSS-Induced Colitis [an abstract of dissertation and a summary of dissertation review]
http://hdl.handle.net/2115/90801
Title: Application of Benchtop NMR for Metabolomics Study Using Feces of Mice with DSS-Induced Colitis [an abstract of dissertation and a summary of dissertation review]
Authors: 宋, 子豪2023-09-24T15:00:00Z宋, 子豪Clarification for Molecular Structure-Physical Property Correlation of Alkyl-π Functional Molecular Liquids [an abstract of dissertation and a summary of dissertation review]
http://hdl.handle.net/2115/90800
Title: Clarification for Molecular Structure-Physical Property Correlation of Alkyl-π Functional Molecular Liquids [an abstract of dissertation and a summary of dissertation review]
Authors: ZHENG, Xiao2023-09-24T15:00:00ZZHENG, XiaoDevelopment of thermo-responsive gold nanodiscs for a novel plasmonic photothermal cancer therapy
http://hdl.handle.net/2115/90716
Title: Development of thermo-responsive gold nanodiscs for a novel plasmonic photothermal cancer therapy
Authors: Mba, Joshua Chidiebere2022-09-25T15:00:00ZMba, Joshua ChidiebereStudy on on-demand functionalization of hydrogel surfaces by force-induced rapid microstructure growth
http://hdl.handle.net/2115/90623
Title: Study on on-demand functionalization of hydrogel surfaces by force-induced rapid microstructure growth
Authors: Mu, Qifeng2022-12-25T15:00:00ZMu, QifengStudy on mechanoradical generation and application in azo-crosslinked double network hydrogels
http://hdl.handle.net/2115/90621
Title: Study on mechanoradical generation and application in azo-crosslinked double network hydrogels
Authors: 王, 志健2022-09-25T15:00:00Z王, 志健