The yeast Pichia pastoris(P. pastoris) has been used for the expression of heterologous proteins with the significant success. However, it is time-consuming to screen the high expression level of the recombinant P. pa...The yeast Pichia pastoris(P. pastoris) has been used for the expression of heterologous proteins with the significant success. However, it is time-consuming to screen the high expression level of the recombinant P. pastoris directly. Thus, for β-mannanase production, developing the accurate, rapid and inexpensive screening method to substitute random screening is certainly required. A simple method based on the size of hydrolysis hole was described here, but this method was not very accurate that could only be used in preliminary screening. To further improve the accuracy, a micro-plate screening method is established, which appears to be more accurate and effective. The efficiency of this screening method is about 10 times higher than that of the general screening strategy of cultivation in shaking flasks. Two methods presented here can also be used for screening of recombinant Pichia strains with high-level expression of other heterologous protein after modification.展开更多
Background:In-feed antibiotics are being phased out in livestock production worldwide.Alternatives to antibiotics are urgently needed to maintain animal health and production performance.Host defense peptides(HDPs)are...Background:In-feed antibiotics are being phased out in livestock production worldwide.Alternatives to antibiotics are urgently needed to maintain animal health and production performance.Host defense peptides(HDPs)are known for their broad-spectrum antimicrobial and immunomodulatory capabilities.Enhancing the synthesis of endogenous HDPs represents a promising antibiotic alternative strategy to disease control and prevention.Methods:To identify natural products with an ability to stimulate the synthesis of endogenous HDPs,we performed a high-throughput screening of 1261 natural products using a newly-established stable luciferase reporter cell line known as IPEC-J2/pBD3-luc.The ability of the hit compounds to induce HDP genes in porcine IPEC-J2 intestinal epithelial cells,3D4/31 macrophages,and jejunal explants were verified using RT-qPCR.Augmentation of the antibacterial activity of porcine 3D4/31 macrophages against a Gram-negative bacterium(enterotoxigenic E.coli)and a Gram-positive bacterium(Staphylococcus aureus)were further confirmed with four selected HDP-inducing compounds.Results:A total of 48 natural products with a minimum Z-score of 2.0 were identified after high-throughput screening,with 21 compounds giving at least 2-fold increase in luciferase activity in a follow-up dose-response experiment.Xanthohumol and deoxyshikonin were further found to be the most potent in inducing pBD3 mRNA expression,showing a minimum 10-fold increase in IPEC-J2,3D4/31 cells,and jejunal explants.Other compounds such as isorhapontigenin and calycosin also enhanced pBD3 mRNA expression by at least 10-fold in both IPEC-J2 cells and jejunal explants,but not 3D4/31 cells.In addition to pBD3,other porcine HDP genes such as pBD2,PG1-5,and pEP2C were induced to different magnitudes by xanthohumol,deoxyshikonin,isorhapontigenin,and calycosin,although clear gene-and cell type-specific patterns of regulation were observed.Desirably,these four compounds had a minimum effect on the expression of several representative inflammatory cytokine genes.Furthermore,when used at HDP-inducing concentrations,these compounds showed no obvious direct antibacterial activity,but significantly augmented the antibacterial activity of 3D4/31 macrophages(P<0.05)against both Gram-negative and Gram-positive bacteria.Conclusions:Our results indicate that these newly-identified natural HDP-inducing compounds have the potential to be developed as novel alternatives to antibiotics for prophylactic and therapeutic treatment of infectious diseases in livestock production.展开更多
One-third of top-selling drugs are derived from natural products. When only a fraction of the bioactive natural products diversity has been explored, huge opportunities still remain for discovering novel leads for the...One-third of top-selling drugs are derived from natural products. When only a fraction of the bioactive natural products diversity has been explored, huge opportunities still remain for discovering novel leads for the development of new drugs. Clear cell renal cell carcinoma (ccRCC) is a highly vascular tumour arising from epithelial elements. Mutations in the Von Hippel-Lindau (VHL) gene are responsible for VHL disease and arise in the majority of Renal Cell Carcinoma (RCC) as well as in other types of cancer. Renal carcinoma cell lines with naturally occurring VHL mutations (RCC4 VA) and their genetically matched wild-type VHL (RCC4 VHL) counterparts were seeded onto 96-well plates and allowed to attach overnight. Fungal extracts were tested on both cell lines. Clinically useful antitumor agents were used as positive controls and as reference points to establish the efficacy and selectivity of the new compounds. Renal cell carcinoma cell lines expressing VHL or not were treated with Carboxyfluorescein succinimidyl ester (CFSE). The day after cell inoculation, extracts were added and during the following days of incubation, fluorescence intensity was measured as a surrogate marker for cell viability. The most promising extracts selectively inhibited growth of pVHL-defi- cient cells but not of wild-type VHL cells. We used High Content Bio-imaging, a complete cellular imaging workflow that integrates instruments and software to acquire and analyze images, to evaluate their effect. Cell imaging can reveal effects that would be overlooked by other cell assay approaches. This target-based whole cell screen is a new strategy, which ensures cell permeability and target selectivity especially in natural product screening where natural product purification is a labour of extensive work. This approach permitted a dynamic study where fluorescence was measured without affecting cell viability and enabling a better detection of cytotoxic effects such as autophagy, senescence or late apoptosis.展开更多
Sheep are one of the most economically important domesticated animals for human society. However, genetic improvements for the key traits associated with meat, growth, milk, wool, reproduction, horns and tails progres...Sheep are one of the most economically important domesticated animals for human society. However, genetic improvements for the key traits associated with meat, growth, milk, wool, reproduction, horns and tails progress slowly using conventional crossbreeding methods. With the development and utilization of highthroughput screening technologies over the last decade, a list of functional genes and genetic variants associated with these traits has been identified. This review covers recent genome-wide studies on sheep productive traits using high-throughput screening technologies, including those based on single-nucleotide polymorphisms and copy number variants at the whole-genome level(e.g.,genome-wide association studies), transcriptome and DNA methylation sequences. Additionally, comprehensive information on functional genes and genetic variants associated with economically important traits in sheep is provided.展开更多
目的基于高效液相色谱-四极杆-飞行时间质谱法(high performance liquid chromatography quadrupole time of flight mass spectrometry,LC-QTOF/MS)建立蔬菜中124种药物和个人护理品(pharmaceuticals and personal care products,PPCPs...目的基于高效液相色谱-四极杆-飞行时间质谱法(high performance liquid chromatography quadrupole time of flight mass spectrometry,LC-QTOF/MS)建立蔬菜中124种药物和个人护理品(pharmaceuticals and personal care products,PPCPs)的同时快速筛查、确证和定量分析方法。方法样品经过10 m L乙腈提取,改进QuEChERS方法净化,电喷雾电离模式,外标法定量;建立一级精确质量数据库、色谱保留时间和二级质谱库,实现蔬菜中124种目标污染物的快速筛查和确证。结果在5~500μg/L质量浓度范围内,124种目标化合物的线性关系良好(r>0.99)。多种蔬菜基质中10、50、200μg/kg的3个加标水平下平均回收率为62.7%~117.2%,相对标准偏差为1.6%~8.9%。满足痕量分析要求,基质干扰效应消除效果较好,该方法具有良好的净化效果。结论该方法具有操作简便;耗时短;灵敏度高;稳定性好的优点,适用于蔬菜基质中PPCPs的筛查检测及定量分析,对蔬菜质量安全的快速筛查具有技术支撑意义。展开更多
基金Project(CX2012B124)supported by the Graduate Degree Thesis Innovation Program of Hunan ProvinceChina+3 种基金Project(13JJ9002)supported by the Natural Science Foundation of Hunan ProvinceChinaProject(2012XK4081)supported by the Key Science and Technology Plan of Hunan Provincial Science&Technology DepartmentChina
文摘The yeast Pichia pastoris(P. pastoris) has been used for the expression of heterologous proteins with the significant success. However, it is time-consuming to screen the high expression level of the recombinant P. pastoris directly. Thus, for β-mannanase production, developing the accurate, rapid and inexpensive screening method to substitute random screening is certainly required. A simple method based on the size of hydrolysis hole was described here, but this method was not very accurate that could only be used in preliminary screening. To further improve the accuracy, a micro-plate screening method is established, which appears to be more accurate and effective. The efficiency of this screening method is about 10 times higher than that of the general screening strategy of cultivation in shaking flasks. Two methods presented here can also be used for screening of recombinant Pichia strains with high-level expression of other heterologous protein after modification.
基金supported by the National Natural Science Foundation of China(31972576)the Beijing Natural Science Foundation(6202004)+2 种基金the Special Program on Science and Technology Innovation Capacity Building of BAAFS(KJCX20180414 and KJCX201914)the USDA National Institute of Food and Agriculture(2018-68003-27462 and 2018-33610-28252)the Oklahoma Center for the Advancement of Science and Technology(AR19-27)。
文摘Background:In-feed antibiotics are being phased out in livestock production worldwide.Alternatives to antibiotics are urgently needed to maintain animal health and production performance.Host defense peptides(HDPs)are known for their broad-spectrum antimicrobial and immunomodulatory capabilities.Enhancing the synthesis of endogenous HDPs represents a promising antibiotic alternative strategy to disease control and prevention.Methods:To identify natural products with an ability to stimulate the synthesis of endogenous HDPs,we performed a high-throughput screening of 1261 natural products using a newly-established stable luciferase reporter cell line known as IPEC-J2/pBD3-luc.The ability of the hit compounds to induce HDP genes in porcine IPEC-J2 intestinal epithelial cells,3D4/31 macrophages,and jejunal explants were verified using RT-qPCR.Augmentation of the antibacterial activity of porcine 3D4/31 macrophages against a Gram-negative bacterium(enterotoxigenic E.coli)and a Gram-positive bacterium(Staphylococcus aureus)were further confirmed with four selected HDP-inducing compounds.Results:A total of 48 natural products with a minimum Z-score of 2.0 were identified after high-throughput screening,with 21 compounds giving at least 2-fold increase in luciferase activity in a follow-up dose-response experiment.Xanthohumol and deoxyshikonin were further found to be the most potent in inducing pBD3 mRNA expression,showing a minimum 10-fold increase in IPEC-J2,3D4/31 cells,and jejunal explants.Other compounds such as isorhapontigenin and calycosin also enhanced pBD3 mRNA expression by at least 10-fold in both IPEC-J2 cells and jejunal explants,but not 3D4/31 cells.In addition to pBD3,other porcine HDP genes such as pBD2,PG1-5,and pEP2C were induced to different magnitudes by xanthohumol,deoxyshikonin,isorhapontigenin,and calycosin,although clear gene-and cell type-specific patterns of regulation were observed.Desirably,these four compounds had a minimum effect on the expression of several representative inflammatory cytokine genes.Furthermore,when used at HDP-inducing concentrations,these compounds showed no obvious direct antibacterial activity,but significantly augmented the antibacterial activity of 3D4/31 macrophages(P<0.05)against both Gram-negative and Gram-positive bacteria.Conclusions:Our results indicate that these newly-identified natural HDP-inducing compounds have the potential to be developed as novel alternatives to antibiotics for prophylactic and therapeutic treatment of infectious diseases in livestock production.
文摘One-third of top-selling drugs are derived from natural products. When only a fraction of the bioactive natural products diversity has been explored, huge opportunities still remain for discovering novel leads for the development of new drugs. Clear cell renal cell carcinoma (ccRCC) is a highly vascular tumour arising from epithelial elements. Mutations in the Von Hippel-Lindau (VHL) gene are responsible for VHL disease and arise in the majority of Renal Cell Carcinoma (RCC) as well as in other types of cancer. Renal carcinoma cell lines with naturally occurring VHL mutations (RCC4 VA) and their genetically matched wild-type VHL (RCC4 VHL) counterparts were seeded onto 96-well plates and allowed to attach overnight. Fungal extracts were tested on both cell lines. Clinically useful antitumor agents were used as positive controls and as reference points to establish the efficacy and selectivity of the new compounds. Renal cell carcinoma cell lines expressing VHL or not were treated with Carboxyfluorescein succinimidyl ester (CFSE). The day after cell inoculation, extracts were added and during the following days of incubation, fluorescence intensity was measured as a surrogate marker for cell viability. The most promising extracts selectively inhibited growth of pVHL-defi- cient cells but not of wild-type VHL cells. We used High Content Bio-imaging, a complete cellular imaging workflow that integrates instruments and software to acquire and analyze images, to evaluate their effect. Cell imaging can reveal effects that would be overlooked by other cell assay approaches. This target-based whole cell screen is a new strategy, which ensures cell permeability and target selectivity especially in natural product screening where natural product purification is a labour of extensive work. This approach permitted a dynamic study where fluorescence was measured without affecting cell viability and enabling a better detection of cytotoxic effects such as autophagy, senescence or late apoptosis.
基金financially supported by the National Natural Science Foundation of China (31272413, 3161101336)the National Transgenic Breeding Project of China (2014ZX0800952B)+1 种基金the External Cooperation Program of Chinese Academy of Sciences (152111KYSB20150010)the Taishan Scholars Program of Shandong Province (201511085)
文摘Sheep are one of the most economically important domesticated animals for human society. However, genetic improvements for the key traits associated with meat, growth, milk, wool, reproduction, horns and tails progress slowly using conventional crossbreeding methods. With the development and utilization of highthroughput screening technologies over the last decade, a list of functional genes and genetic variants associated with these traits has been identified. This review covers recent genome-wide studies on sheep productive traits using high-throughput screening technologies, including those based on single-nucleotide polymorphisms and copy number variants at the whole-genome level(e.g.,genome-wide association studies), transcriptome and DNA methylation sequences. Additionally, comprehensive information on functional genes and genetic variants associated with economically important traits in sheep is provided.
文摘目的基于高效液相色谱-四极杆-飞行时间质谱法(high performance liquid chromatography quadrupole time of flight mass spectrometry,LC-QTOF/MS)建立蔬菜中124种药物和个人护理品(pharmaceuticals and personal care products,PPCPs)的同时快速筛查、确证和定量分析方法。方法样品经过10 m L乙腈提取,改进QuEChERS方法净化,电喷雾电离模式,外标法定量;建立一级精确质量数据库、色谱保留时间和二级质谱库,实现蔬菜中124种目标污染物的快速筛查和确证。结果在5~500μg/L质量浓度范围内,124种目标化合物的线性关系良好(r>0.99)。多种蔬菜基质中10、50、200μg/kg的3个加标水平下平均回收率为62.7%~117.2%,相对标准偏差为1.6%~8.9%。满足痕量分析要求,基质干扰效应消除效果较好,该方法具有良好的净化效果。结论该方法具有操作简便;耗时短;灵敏度高;稳定性好的优点,适用于蔬菜基质中PPCPs的筛查检测及定量分析,对蔬菜质量安全的快速筛查具有技术支撑意义。
