Background:Bitter taste receptors(Tas2rs)are generally considered to sense various bitter compounds to escape the intake of toxic substances.Bitter taste receptors have been found to widely express in extraoral tissue...Background:Bitter taste receptors(Tas2rs)are generally considered to sense various bitter compounds to escape the intake of toxic substances.Bitter taste receptors have been found to widely express in extraoral tissues and have important physiological functions outside the gustatory system in vivo.Methods:To investigate the physiological functions of the bitter taste receptor cluster Tas2r106/Tas2r104/Tas2r105/Tas2r114 in lingual and extraoral tissues,multiple Tas2rs mutant mice and Gnat3 were produced using CRISPR/Cas9 gene-editing technique.A mixture containing Cas9 and sgRNA mRNAs for Tas2rs and Gnat3 gene was microinjected into the cytoplasm of the zygotes.Then,T7EN1 assays and sequencing were used to screen genetic mutation at the target sites in founder mice.Quantitative real-time polymerase chain reaction(qRT-PCR)and immunostaining were used to study the expression level of taste signaling cascade and bitter taste receptor in taste buds.Perception to taste substance was also studied using twobottle preference tests.Results:We successfully produced several Tas2rs and Gnat3 mutant mice using the CRISPR/Cas9 technique.Immunostaining results showed that the expression of GNAT3 and PLCB2 was not altered in Tas2rs mutant mice.But qRT-PCR results revealed the changed expression profile of m Tas2rs gene in taste buds of these mutant mice.With two-bottle preference tests,these mutant mice eliminate responses to cycloheximide due to genetic mutation of Tas2r105.In addition,these mutant mice showed a loss of taste perception to quinine dihydrochloride,denatonium benzoate,and cucurbitacin B(CuB).Gnat3-mediated taste receptor and its signal pathway contribute to CuB perception.Conclusions:These findings implied that these mutant mice would be a valuable means to understand the biological functions of TAS2Rs in extraoral tissues and investigate bitter compound-induced responses mediated by these TAS2Rs in many extraoral tissues.展开更多
Though the transition-metal dichalcogenides （TMDs） were proven to have a better performance on the hydrogen evolution reaction （HER）, the bulk production of active TMD materials remains a challenging work. This re...Though the transition-metal dichalcogenides （TMDs） were proven to have a better performance on the hydrogen evolution reaction （HER）, the bulk production of active TMD materials remains a challenging work. This report overcomes those barriers by showing a simple procedure to synthesize TaS2 nanosheets through modifying the arc discharge process. The usage of chloride as the transporting agent reduces the growth period of the formed TaS2 with active edge sites. TaS2 is found to have a uniform thickness （4 nm） with high crystallinity and adopt a 2H polytype （double-layered hexagonal） structure. The as-synthesized TaS2 has superior activity for HER with the potential of 280 mV.展开更多
目的旨在建立一种基于生物传感器联合超高效液相色谱/串联质谱(ultra-performance liquid chromatography with electrospray tandem mass spectrometry,UPLC-MS/MS)的中药苦味关键质量属性辨识方法。以白术内酯类成分为研究对象,通过...目的旨在建立一种基于生物传感器联合超高效液相色谱/串联质谱(ultra-performance liquid chromatography with electrospray tandem mass spectrometry,UPLC-MS/MS)的中药苦味关键质量属性辨识方法。以白术内酯类成分为研究对象,通过分子对接与生物传感技术揭示其与苦味受体的相互作用机制,实现苦味属性从传统经验判定到分子水平表征的跨越,为完善白术质量控制体系提供支撑。方法采用D101大孔吸附树脂结合紫外分光光度法,制备并筛选富含内酯类成分的白术组分;通过UPLC-MS/MS与分子对接技术,在分子水平解析白术组分与味觉受体的相互作用特征;采用生物传感器与UPLCMS/MS联用技术,实现白术组分苦味关键质量属性的精准辨识。结果成功制得白术不同极性组分11个,其中白术醇提物70%组分的总内酯含量最高,为后续性味研究的理想载体;分子对接实验显示白术组分与Ⅱ型味觉受体家族14号成员(taste receptor type 2 member 14,TAS2R14)的结合展现出明显优势,在分子层面揭示了白术组分具有强烈趋于苦味属性的作用特质;进一步构建苦味生物传感器,对白术组分的苦味属性进行表征,结果显示白术组分与TAS2R14的相互结合强度为49.0ng/L,属于强相互作用,表明以内酯类成分为主的白术组分具有显著的苦味属性,该结果与分子对接结果相互印证,增强了实验结论的可靠性;最后,联合UPLC-MS/MS技术,共辨识得到包括白术内酯Ⅱ在内的苦味关键质量属性13个,在物质基础层面表明白术组分与苦味受体TAS2R14的结合受关键质量属性驱动,为理解白术内酯类成分苦味特性提供直接证据。结论通过多技术融合的系统性研究,从分子相互作用到物质基础层面揭示了白术内酯类成分苦味属性的本质,所发现的苦味关键质量属性为建立基于苦味特征的白术质量控制方法奠定了理论基础,此外,提出的技术路线为中药苦味物质基础研究提供了新的方法学参考。展开更多
基金Shanghai Science and Technology Commission“R&D Public Service Platform and Institutional Capacity Improvement Project”,Grant/Award Number:21DZ2291300National Science and Technology Major Project,Grant/Award Number:2017ZX10304402-001-006 and 2017ZX10304402-001-012Start-on Funding from Shanghai Public Health Clinical Center,Grant/Award Number:KY-GW-2019-11,KYGW-2019-19 and KY-GW-2021-39。
文摘Background:Bitter taste receptors(Tas2rs)are generally considered to sense various bitter compounds to escape the intake of toxic substances.Bitter taste receptors have been found to widely express in extraoral tissues and have important physiological functions outside the gustatory system in vivo.Methods:To investigate the physiological functions of the bitter taste receptor cluster Tas2r106/Tas2r104/Tas2r105/Tas2r114 in lingual and extraoral tissues,multiple Tas2rs mutant mice and Gnat3 were produced using CRISPR/Cas9 gene-editing technique.A mixture containing Cas9 and sgRNA mRNAs for Tas2rs and Gnat3 gene was microinjected into the cytoplasm of the zygotes.Then,T7EN1 assays and sequencing were used to screen genetic mutation at the target sites in founder mice.Quantitative real-time polymerase chain reaction(qRT-PCR)and immunostaining were used to study the expression level of taste signaling cascade and bitter taste receptor in taste buds.Perception to taste substance was also studied using twobottle preference tests.Results:We successfully produced several Tas2rs and Gnat3 mutant mice using the CRISPR/Cas9 technique.Immunostaining results showed that the expression of GNAT3 and PLCB2 was not altered in Tas2rs mutant mice.But qRT-PCR results revealed the changed expression profile of m Tas2rs gene in taste buds of these mutant mice.With two-bottle preference tests,these mutant mice eliminate responses to cycloheximide due to genetic mutation of Tas2r105.In addition,these mutant mice showed a loss of taste perception to quinine dihydrochloride,denatonium benzoate,and cucurbitacin B(CuB).Gnat3-mediated taste receptor and its signal pathway contribute to CuB perception.Conclusions:These findings implied that these mutant mice would be a valuable means to understand the biological functions of TAS2Rs in extraoral tissues and investigate bitter compound-induced responses mediated by these TAS2Rs in many extraoral tissues.
基金This work was supported by the National Natural Science Foundation of China （Grant Nos. 21576289 and 21322609）, the Science Foundation Research Funds Provided to New Recruitments of China University of Petroleum, Beijing （2462014QZDX01） and the Thousand Talents Program.
文摘Though the transition-metal dichalcogenides （TMDs） were proven to have a better performance on the hydrogen evolution reaction （HER）, the bulk production of active TMD materials remains a challenging work. This report overcomes those barriers by showing a simple procedure to synthesize TaS2 nanosheets through modifying the arc discharge process. The usage of chloride as the transporting agent reduces the growth period of the formed TaS2 with active edge sites. TaS2 is found to have a uniform thickness （4 nm） with high crystallinity and adopt a 2H polytype （double-layered hexagonal） structure. The as-synthesized TaS2 has superior activity for HER with the potential of 280 mV.
文摘目的旨在建立一种基于生物传感器联合超高效液相色谱/串联质谱(ultra-performance liquid chromatography with electrospray tandem mass spectrometry,UPLC-MS/MS)的中药苦味关键质量属性辨识方法。以白术内酯类成分为研究对象,通过分子对接与生物传感技术揭示其与苦味受体的相互作用机制,实现苦味属性从传统经验判定到分子水平表征的跨越,为完善白术质量控制体系提供支撑。方法采用D101大孔吸附树脂结合紫外分光光度法,制备并筛选富含内酯类成分的白术组分;通过UPLC-MS/MS与分子对接技术,在分子水平解析白术组分与味觉受体的相互作用特征;采用生物传感器与UPLCMS/MS联用技术,实现白术组分苦味关键质量属性的精准辨识。结果成功制得白术不同极性组分11个,其中白术醇提物70%组分的总内酯含量最高,为后续性味研究的理想载体;分子对接实验显示白术组分与Ⅱ型味觉受体家族14号成员(taste receptor type 2 member 14,TAS2R14)的结合展现出明显优势,在分子层面揭示了白术组分具有强烈趋于苦味属性的作用特质;进一步构建苦味生物传感器,对白术组分的苦味属性进行表征,结果显示白术组分与TAS2R14的相互结合强度为49.0ng/L,属于强相互作用,表明以内酯类成分为主的白术组分具有显著的苦味属性,该结果与分子对接结果相互印证,增强了实验结论的可靠性;最后,联合UPLC-MS/MS技术,共辨识得到包括白术内酯Ⅱ在内的苦味关键质量属性13个,在物质基础层面表明白术组分与苦味受体TAS2R14的结合受关键质量属性驱动,为理解白术内酯类成分苦味特性提供直接证据。结论通过多技术融合的系统性研究,从分子相互作用到物质基础层面揭示了白术内酯类成分苦味属性的本质,所发现的苦味关键质量属性为建立基于苦味特征的白术质量控制方法奠定了理论基础,此外,提出的技术路线为中药苦味物质基础研究提供了新的方法学参考。
