Escherichia coli O157:H7 is one of the major foodborne pathogenic bacterial that cause infectious diseases in humans.The previous found that a combination of kojic acid and tea polyphenols exhibited better activity ag...Escherichia coli O157:H7 is one of the major foodborne pathogenic bacterial that cause infectious diseases in humans.The previous found that a combination of kojic acid and tea polyphenols exhibited better activity against E.coli O157:H7 than using either alone.This study aimed to explore responses underlying the antibacterial mechanisms of kojic acid and tea polyphenols from the gene level.The functional enrichment analysis by comparing kojic acid and tea polyphenols individually or synergistically against E.coli O157:H7 found that acid resistance systems in kojic acid were activated,and the cell membrane and genomic DNA were destructed in the cells,resulting in“oxygen starvation”.The oxidative stress response triggered by tea polyphenols inhibited both sulfur uptake and the synthesis of ATP,which affected the bacteria's life metabolic process.Interestingly,we found that kojic acid combined with tea polyphenols hindered the uptake of iron that played an essential role in the synthesis of DNA,respiration,tricarboxylic acid cycle.The results suggested that the iron uptake pathways may represent a novel approach for kojic acid and tea polyphenols synergistically against E.coli O157:H7 and provided a theoretical basis for bacterial pathogen control in the food industry.展开更多
Non-alcoholic fatty liver disease(NAFLD)is associated with mutations in lipopolysaccharide-binding protein(LBP),but the underlying epigenetic mechanisms remain understudied.Herein,LBP^(-/-)rats with NAFLD were establi...Non-alcoholic fatty liver disease(NAFLD)is associated with mutations in lipopolysaccharide-binding protein(LBP),but the underlying epigenetic mechanisms remain understudied.Herein,LBP^(-/-)rats with NAFLD were established and used to conduct integrative targetingactive enhancer histone H3 lysine 27 acetylation(H3K27ac)chromatin immunoprecipitation coupled with high-throughput and transcriptomic sequencing analysis to explore the potential epigenetic pathomechanisms of active enhancers of NAFLD exacerbation upon LBP deficiency.Notably,LBP^(-/-)reduced the inflammatory response but markedly aggravated high-fat diet(HFD)-induced NAFLD in rats,with pronounced alterations in the histone acetylome and regulatory transcriptome.In total,1128 differential enhancer-target genes significantly enriched in cholesterol and fatty acid metabolism were identified between wild-type(WT)and LBP^(-/-)NAFLD rats.Based on integrative analysis,CCAAT/enhancer-binding proteinβ(C/EBPβ)was identified as a pivotal transcription factor(TF)and contributor to dysregulated histone acetylome H3K27ac,and the lipid metabolism gene SCD was identified as a downstream effector exacerbating NAFLD.This study not only broadens our understanding of the essential role of LBP in the pathogenesis of NAFLD from an epigenetics perspective but also identifies key TF C/EBPβand functional gene SCD as potential regulators and therapeutic targets.展开更多
To explain the presence and spatial distribution of NO_(3)^(−)and N-NH_(3)in the Aquifer of the Metropolitan Area of Mexico City(AMAMC),a hydrogeochemical and isotopic analysis using^(13)C DIC(as well as the stable is...To explain the presence and spatial distribution of NO_(3)^(−)and N-NH_(3)in the Aquifer of the Metropolitan Area of Mexico City(AMAMC),a hydrogeochemical and isotopic analysis using^(13)C DIC(as well as the stable isotopes^(18)O and^(2)H)in groundwater was conducted.This aquifer is located in an old closed lacustrine volcano-sedimentary basin;some wells hosted in the semi-confined zone contain high N-NH_(3)concentrations,while others present NO_(3)^(−)contents in the recharge zones(hosted in an oxidizing environment).In this study,a change in the isotopic signature(primarily in^(18)O and^(2)H)was observed from the recharge zones to the basin center in some of the wells with high NO_(3)^(−)concentrations,this behavior can be attributed to evaporation during the incorporation of recently infiltrated water.In addition,the results for^(13)C(along with ^(2) H)in wells with the highest N-NH_(3)concentrations exhibited an atypically broad range of values.Results indicated the occurrence of hydrogeochemical and/or biochemical processes in the aquifer(in an oxidizing or reducing environment),such as organic degradation,bacterial decomposition(primarily in the ancient Lake Texcoco and which acts as a natural sink for carbon,nitrogen,sulfur,and phosphorus),besides rock weathering and dissolution,which may be responsible for a very marked isotopic modification of the^(13)C(and,to a lesser extent,2 H).Methanotrophic bacterial activity and methanogenic activity may be related to N-NH_(3)removal processes by oxidation and residual water incorporation respectively,whereas the increase in the NO_(3)^(−)content in some wells is due to the recent contribution of poor-quality water due to contamination.展开更多
Objective: To explore the protective effect of camellia oil against H2O2-induced oxidative stress injury in rat H9C2 cardiomyocytes. Methods: CCK8 method was used to detect the cell survival rate of H9C2 cardiomyocyte...Objective: To explore the protective effect of camellia oil against H2O2-induced oxidative stress injury in rat H9C2 cardiomyocytes. Methods: CCK8 method was used to detect the cell survival rate of H9C2 cardiomyocytes treated with different concentrations of H2O2. Normal cultured cells were used as the blank control group, and the cells were treated with 200 μmol/L H2O2 for 24 h. An oxidative stress injury model was constructed as the model group. The cells were pretreated with 1%, 0.1% and 0.01% camellia oil for 24 h, and then H2O2 was added for 24 h as the experimental group. The β-galactosidase senescence staining assay, mitochondrial membrane potential assay, EdU cell proliferation staining assay and scratch assay were used to observe the changes of cell senescence, mitochondrial membrane potential, proliferation, apoptosis and migration in each group. The superoxide dismutase (SOD) activity, lactate dehydrogenase (LDH) activity, and malondialdehyde (MDA) content of the cells in each group were detected by using the kit. Results: The cell viability of H9C2 cardiomyocytes treated with different concentrations of H2O2 was inhibited and positively correlated with the concentration of H2O2 (P<0.01). Compared with the blank control group, the positive rate of cell senescence, MDA content and LDH activity increased in the H2O2 model group (P<0.01);mitochondrial membrane potential, cellular value-added rate, migration rate and SOD activity decreased (P<0.01). Compared with the H2O2 model group, the positive rate of cellular senescence (P<0.01 or P<0.05), MDA content and LDH activity decreased (P< 0.01 or P<0.05);mitochondrial membrane potential increased, cell proliferation rate and migration rate increased (P<0.01 or P<0.05) in the experimental group. Conclusion: Camellia oil can significantly inhibit oxidative stress injury in H9C2 cells and exert cardiomyocyte protective effects.展开更多
饱和的碳氢键氧化是合成化学和化学工业中一类重要的化学反应.然而,饱和C(sp^(3))−H键离解能(BDEs)较高、极性较弱,导致了底物难以活化和催化转化效率较低等问题.在过去的几十年,C(sp^(3))−H键的定向活化转化取得了重要的进展.其中,关于...饱和的碳氢键氧化是合成化学和化学工业中一类重要的化学反应.然而,饱和C(sp^(3))−H键离解能(BDEs)较高、极性较弱,导致了底物难以活化和催化转化效率较低等问题.在过去的几十年,C(sp^(3))−H键的定向活化转化取得了重要的进展.其中,关于C(sp^(3))−H键催化氧化的研究主要涉及一些键能低的、预活化的C−H键,包括苄基型、亚甲基型、脂肪族X−CH_(2)(X=O,N)和甲苯等,含有未活化C(sp^(3))−H键的复杂化合物的选择性氧化仍具有挑战性.例如,芳基醚C(sp^(3))−H键功能化通常采用计量的过氧化物氧化剂,或者通过单电子氧化和碱促进的去质子化进一步构建C−C/C−N键,产物选择性较低,也带来了一些不利的环境影响.因此,有必要开发高效、温和的芳基醚C(sp^(3))−H键选择氧化方法,并将其应用于有机合成和药物开发.近年来,光催化C(sp^(3))−H键氧化因其操作简便、氧化还原中性等优点,已发展成为一种有用且多样的催化研究工具.本文发展了一种利用氧气作为氧化剂,在可见光驱动下选择性地将芳基醚C(sp^(3))−H键氧化成为甲酸苯酯类产物的新方法.使用Mes-10-phenyl-Acr^(+)−BF_(4)^(-)光催化剂,高效活化多种氯源(如盐酸、无机氯盐和有机氯化物)得到氯自由基,由于其具有较高的氧化能力(+2.03 V vs.SCE)和对氢原子的亲和力,能够通过氢原子转移过程活化芳基醚C(sp^(3))−键,攫取氢自由基得到相应的烷基碳自由基(•CH_(2)OPh)中间体,进一步被分子氧选择氧化得到酯类目标产物.研究结果表明,多种链状芳基醚和不同取代(如给电子基和吸电子基)芳基醚均可发生氧化反应,高收率地合成了一系列官能团丰富的甲酸苯酯类化合物.本文方法具有反应条件温和、操作简单、官能团耐受性好以及可规模化放大等优点,并且少量的水对反应没有明显影响.机理实验研究结果表明,芳基醚C(sp^(3))−H键的断裂是反应过程的决速步骤.紫外可见吸收光谱结果表明,氯离子与催化剂之间的相互作用强于底物,并且自由基捕获实验证实反应体系中存在氯自由基和烷基碳自由基物种,表明反应经历自由基路径.此外,电子顺磁共振测试结果表明,反应过程中存在单线态氧物种,可能是激发态的光催化剂直接与氧气发生能量转移得到;同位素实验(18O)揭示了甲酸苯酯类化合物氧的来源.综上,本文实现了温和条件下光催化芳基醚C(sp^(3))−H键选择氧化反应,高收率合成了一系列甲酸苯酯类化合物.该方法避免了化学计量的过氧化物和碱等添加剂的使用以及底物的过度氧化,阐明了催化反应机制,为其他醚类化合物的C(sp^(3))−H键氧化功能化提供了新思路,为后续化学合成和药物开发提供了参考和启示.展开更多
基金supported by National Natural Science Foundation of China(31972021)R&D Projects in Key Areas of Guangdong Province(2019B020212003)+4 种基金the Science and Technology Program of Guangzhou,China(202206010177)Guangdong key research and development program(2021B0202060001)Foshan and agricultural academy cooperation projectGuangdong Modern Agriculture project(2022KJ117)Aquatic Products Center Project of GAAS。
文摘Escherichia coli O157:H7 is one of the major foodborne pathogenic bacterial that cause infectious diseases in humans.The previous found that a combination of kojic acid and tea polyphenols exhibited better activity against E.coli O157:H7 than using either alone.This study aimed to explore responses underlying the antibacterial mechanisms of kojic acid and tea polyphenols from the gene level.The functional enrichment analysis by comparing kojic acid and tea polyphenols individually or synergistically against E.coli O157:H7 found that acid resistance systems in kojic acid were activated,and the cell membrane and genomic DNA were destructed in the cells,resulting in“oxygen starvation”.The oxidative stress response triggered by tea polyphenols inhibited both sulfur uptake and the synthesis of ATP,which affected the bacteria's life metabolic process.Interestingly,we found that kojic acid combined with tea polyphenols hindered the uptake of iron that played an essential role in the synthesis of DNA,respiration,tricarboxylic acid cycle.The results suggested that the iron uptake pathways may represent a novel approach for kojic acid and tea polyphenols synergistically against E.coli O157:H7 and provided a theoretical basis for bacterial pathogen control in the food industry.
基金supported by the National Natural Science Foundation of China(81971875,82300661)Natural Science Foundation of Anhui province(2308085QH246)+3 种基金Natural Science Foundation of the Anhui Higher Education Institutions(KJ2021A0205)Basic and Clinical Cooperative Research Program of Anhui Medical University(2019xkjT002,2019xkjT022,2022xkjT013)Talent Training Program,School of Basic Medical Sciences,Anhui Medical University(2022YPJH102)National College Students Innovation and Entrepreneurship Training Program of China(202210366024)。
文摘Non-alcoholic fatty liver disease(NAFLD)is associated with mutations in lipopolysaccharide-binding protein(LBP),but the underlying epigenetic mechanisms remain understudied.Herein,LBP^(-/-)rats with NAFLD were established and used to conduct integrative targetingactive enhancer histone H3 lysine 27 acetylation(H3K27ac)chromatin immunoprecipitation coupled with high-throughput and transcriptomic sequencing analysis to explore the potential epigenetic pathomechanisms of active enhancers of NAFLD exacerbation upon LBP deficiency.Notably,LBP^(-/-)reduced the inflammatory response but markedly aggravated high-fat diet(HFD)-induced NAFLD in rats,with pronounced alterations in the histone acetylome and regulatory transcriptome.In total,1128 differential enhancer-target genes significantly enriched in cholesterol and fatty acid metabolism were identified between wild-type(WT)and LBP^(-/-)NAFLD rats.Based on integrative analysis,CCAAT/enhancer-binding proteinβ(C/EBPβ)was identified as a pivotal transcription factor(TF)and contributor to dysregulated histone acetylome H3K27ac,and the lipid metabolism gene SCD was identified as a downstream effector exacerbating NAFLD.This study not only broadens our understanding of the essential role of LBP in the pathogenesis of NAFLD from an epigenetics perspective but also identifies key TF C/EBPβand functional gene SCD as potential regulators and therapeutic targets.
基金support granted to carry out the research,and for the funding,Dr.Graciela Herrera Zamarron,responsible for the project with Contract number 0266-1O-ED-F-DGAT-UNAM-2-19-1928.
文摘To explain the presence and spatial distribution of NO_(3)^(−)and N-NH_(3)in the Aquifer of the Metropolitan Area of Mexico City(AMAMC),a hydrogeochemical and isotopic analysis using^(13)C DIC(as well as the stable isotopes^(18)O and^(2)H)in groundwater was conducted.This aquifer is located in an old closed lacustrine volcano-sedimentary basin;some wells hosted in the semi-confined zone contain high N-NH_(3)concentrations,while others present NO_(3)^(−)contents in the recharge zones(hosted in an oxidizing environment).In this study,a change in the isotopic signature(primarily in^(18)O and^(2)H)was observed from the recharge zones to the basin center in some of the wells with high NO_(3)^(−)concentrations,this behavior can be attributed to evaporation during the incorporation of recently infiltrated water.In addition,the results for^(13)C(along with ^(2) H)in wells with the highest N-NH_(3)concentrations exhibited an atypically broad range of values.Results indicated the occurrence of hydrogeochemical and/or biochemical processes in the aquifer(in an oxidizing or reducing environment),such as organic degradation,bacterial decomposition(primarily in the ancient Lake Texcoco and which acts as a natural sink for carbon,nitrogen,sulfur,and phosphorus),besides rock weathering and dissolution,which may be responsible for a very marked isotopic modification of the^(13)C(and,to a lesser extent,2 H).Methanotrophic bacterial activity and methanogenic activity may be related to N-NH_(3)removal processes by oxidation and residual water incorporation respectively,whereas the increase in the NO_(3)^(−)content in some wells is due to the recent contribution of poor-quality water due to contamination.
基金National Natural Science Foundation of China(No.82160597)Guangxi Natural Science Foundation Project(No.2020GXNSFAA159148)。
文摘Objective: To explore the protective effect of camellia oil against H2O2-induced oxidative stress injury in rat H9C2 cardiomyocytes. Methods: CCK8 method was used to detect the cell survival rate of H9C2 cardiomyocytes treated with different concentrations of H2O2. Normal cultured cells were used as the blank control group, and the cells were treated with 200 μmol/L H2O2 for 24 h. An oxidative stress injury model was constructed as the model group. The cells were pretreated with 1%, 0.1% and 0.01% camellia oil for 24 h, and then H2O2 was added for 24 h as the experimental group. The β-galactosidase senescence staining assay, mitochondrial membrane potential assay, EdU cell proliferation staining assay and scratch assay were used to observe the changes of cell senescence, mitochondrial membrane potential, proliferation, apoptosis and migration in each group. The superoxide dismutase (SOD) activity, lactate dehydrogenase (LDH) activity, and malondialdehyde (MDA) content of the cells in each group were detected by using the kit. Results: The cell viability of H9C2 cardiomyocytes treated with different concentrations of H2O2 was inhibited and positively correlated with the concentration of H2O2 (P<0.01). Compared with the blank control group, the positive rate of cell senescence, MDA content and LDH activity increased in the H2O2 model group (P<0.01);mitochondrial membrane potential, cellular value-added rate, migration rate and SOD activity decreased (P<0.01). Compared with the H2O2 model group, the positive rate of cellular senescence (P<0.01 or P<0.05), MDA content and LDH activity decreased (P< 0.01 or P<0.05);mitochondrial membrane potential increased, cell proliferation rate and migration rate increased (P<0.01 or P<0.05) in the experimental group. Conclusion: Camellia oil can significantly inhibit oxidative stress injury in H9C2 cells and exert cardiomyocyte protective effects.
文摘饱和的碳氢键氧化是合成化学和化学工业中一类重要的化学反应.然而,饱和C(sp^(3))−H键离解能(BDEs)较高、极性较弱,导致了底物难以活化和催化转化效率较低等问题.在过去的几十年,C(sp^(3))−H键的定向活化转化取得了重要的进展.其中,关于C(sp^(3))−H键催化氧化的研究主要涉及一些键能低的、预活化的C−H键,包括苄基型、亚甲基型、脂肪族X−CH_(2)(X=O,N)和甲苯等,含有未活化C(sp^(3))−H键的复杂化合物的选择性氧化仍具有挑战性.例如,芳基醚C(sp^(3))−H键功能化通常采用计量的过氧化物氧化剂,或者通过单电子氧化和碱促进的去质子化进一步构建C−C/C−N键,产物选择性较低,也带来了一些不利的环境影响.因此,有必要开发高效、温和的芳基醚C(sp^(3))−H键选择氧化方法,并将其应用于有机合成和药物开发.近年来,光催化C(sp^(3))−H键氧化因其操作简便、氧化还原中性等优点,已发展成为一种有用且多样的催化研究工具.本文发展了一种利用氧气作为氧化剂,在可见光驱动下选择性地将芳基醚C(sp^(3))−H键氧化成为甲酸苯酯类产物的新方法.使用Mes-10-phenyl-Acr^(+)−BF_(4)^(-)光催化剂,高效活化多种氯源(如盐酸、无机氯盐和有机氯化物)得到氯自由基,由于其具有较高的氧化能力(+2.03 V vs.SCE)和对氢原子的亲和力,能够通过氢原子转移过程活化芳基醚C(sp^(3))−键,攫取氢自由基得到相应的烷基碳自由基(•CH_(2)OPh)中间体,进一步被分子氧选择氧化得到酯类目标产物.研究结果表明,多种链状芳基醚和不同取代(如给电子基和吸电子基)芳基醚均可发生氧化反应,高收率地合成了一系列官能团丰富的甲酸苯酯类化合物.本文方法具有反应条件温和、操作简单、官能团耐受性好以及可规模化放大等优点,并且少量的水对反应没有明显影响.机理实验研究结果表明,芳基醚C(sp^(3))−H键的断裂是反应过程的决速步骤.紫外可见吸收光谱结果表明,氯离子与催化剂之间的相互作用强于底物,并且自由基捕获实验证实反应体系中存在氯自由基和烷基碳自由基物种,表明反应经历自由基路径.此外,电子顺磁共振测试结果表明,反应过程中存在单线态氧物种,可能是激发态的光催化剂直接与氧气发生能量转移得到;同位素实验(18O)揭示了甲酸苯酯类化合物氧的来源.综上,本文实现了温和条件下光催化芳基醚C(sp^(3))−H键选择氧化反应,高收率合成了一系列甲酸苯酯类化合物.该方法避免了化学计量的过氧化物和碱等添加剂的使用以及底物的过度氧化,阐明了催化反应机制,为其他醚类化合物的C(sp^(3))−H键氧化功能化提供了新思路,为后续化学合成和药物开发提供了参考和启示.
