目的探讨山茱萸提取物(Cornus officinalis extract,COE)对紫外线B(ultraviolet-B,UVB)辐射引起的皮肤损伤的修复作用,并探讨其潜在的作用机制。方法通过检测人角化细胞(human keratinocytes cells,Ha Ca T)中UVB诱导的基质金属蛋白酶(m...目的探讨山茱萸提取物(Cornus officinalis extract,COE)对紫外线B(ultraviolet-B,UVB)辐射引起的皮肤损伤的修复作用,并探讨其潜在的作用机制。方法通过检测人角化细胞(human keratinocytes cells,Ha Ca T)中UVB诱导的基质金属蛋白酶(matrix metalloproteinases,MMPs)及促炎细胞因子的表达,评估COE的光保护作用,并对其抗氧化酶活性及胶原蛋白含量进行评价。小鼠无毛皮肤在UVB辐射下暴露后,局部应用提取物,并测定表皮厚度、皮肤含水量及胶原mRNA的表达量。结果在UVB照射(354.128 m J/cm^(2))下,1.00mg/m L COE显著增强了抗氧化酶活性,显著降低了促炎细胞因子前列腺素E2、白细胞介素1α、白细胞介素6的表达;同时降低了MMPs的表达;胶原蛋白含量显著增加,Ⅰ型胶原和Ⅲ型胶原蛋白的表达量分别增加13%和75%。此外,COE能够减轻UVB辐射引起的小鼠皮肤表皮增厚及胶原蛋白的丧失。同时,COE处理使丙二醛(malondialdehyde,MDA)含量降低69%,超氧化物歧化酶(superoxide dismutase,SOD)、谷胱甘肽过氧化物酶(clutathione peroxidase,GSH-Px)活性分别升高27%和234%。对小鼠表皮m RNA表达的分析表明,用COE处理导致Mmp1a和Mmp3 mRNA表达水平降低,Col1a1和Col3a1 m RNA水平升高。结论COE能够有效改善UVB辐射引起的皮肤损伤,其作用机制可能与抗氧化酶活性的增强以及促炎细胞因子和MMPs表达的抑制密切相关。本研究旨在通过小鼠和细胞模型进一步探究山茱萸对UVB诱导的皮肤损伤的光保护潜力并阐明其潜在机制,为治疗由UVB光老化导致皮肤疾病的研究和山茱萸新药开发提供理论依据。展开更多
医学英语学习通常以教师为主导,教学方法较单一,学生大多在一种被动状态下学习,因缺乏学习兴趣和主动性而使教学效果不甚理想。笔者采用循序渐进的多元化教学模式,与某些基础医学学科和临床医学学科整合,为学生建立一个开放平台,让学生...医学英语学习通常以教师为主导,教学方法较单一,学生大多在一种被动状态下学习,因缺乏学习兴趣和主动性而使教学效果不甚理想。笔者采用循序渐进的多元化教学模式,与某些基础医学学科和临床医学学科整合,为学生建立一个开放平台,让学生逐步了解将来可能的职业环境及如何设计相应的自学框架,在注重培养和提高医学英语应用能力的同时,注重学生自学等能力的培养,贯彻＂学会学习、边干边学、终身学习（learn to learn,learn by doing,life-longlearning）的教学理念，让学生在学习相关医学专业知识的实践中提高医学英语听、说、读、写及应对能力。展开更多
Objectives To identify the 5'untranslated region of Zika virus(ZIKV 5'UTR)RNA-binding proteins and to investigate the impact of the binding protein on the activity of internal ribosomal entry site(IRES)located...Objectives To identify the 5'untranslated region of Zika virus(ZIKV 5'UTR)RNA-binding proteins and to investigate the impact of the binding protein on the activity of internal ribosomal entry site(IRES)located in ZIKV 5'UTR and virus production.Methods Interacting proteins in U251 cells were captured using tRSA-tagged ZIKV 5'UTR RNA and tRSA-ZIKV 5'UTR RNA-binding proteins were visualized by SDS-PAGE silver staining,Subsequently,liquid chromatographytandem mass spectrometry(LC-MS/MS),bioinformatics analysis,and Western blot were used to identify the candidate proteins binding to ZIKV 5'UTR.Dicistronic expression assay and plaque forming assay were performed to analyze the effect of the binding protein on ZIKV IRES activity and ZIKV production,respecitvely.Results tRSA RNA pull-down assay,LC-MS/MS,and Western blot analysis showed that polypyrimidine tractbinding protein(PTB)bound to the ZIKV 5'UTR.Furthermore,dual luciferase reporter assay revealed that overexpression of PTB significantly enhanced the IRES activity of ZIKV(t=10.220,P<0.001),while PTB knockdown had the opposite effect(t=4.897,P<0.01).Additionally,virus plaque forming assay demonstrated that up-regulation of PTB expression significantly enhanced viral titer(t=6.400,P<0.01),whereas reducing PTB expression level weakened virus infectivity(t=5.055,P<0.01).Conclusion PTB positively interacts with the ZIKV 5'UTR and enhances IRES activity and virus production.展开更多
文摘目的探讨山茱萸提取物(Cornus officinalis extract,COE)对紫外线B(ultraviolet-B,UVB)辐射引起的皮肤损伤的修复作用,并探讨其潜在的作用机制。方法通过检测人角化细胞(human keratinocytes cells,Ha Ca T)中UVB诱导的基质金属蛋白酶(matrix metalloproteinases,MMPs)及促炎细胞因子的表达,评估COE的光保护作用,并对其抗氧化酶活性及胶原蛋白含量进行评价。小鼠无毛皮肤在UVB辐射下暴露后,局部应用提取物,并测定表皮厚度、皮肤含水量及胶原mRNA的表达量。结果在UVB照射(354.128 m J/cm^(2))下,1.00mg/m L COE显著增强了抗氧化酶活性,显著降低了促炎细胞因子前列腺素E2、白细胞介素1α、白细胞介素6的表达;同时降低了MMPs的表达;胶原蛋白含量显著增加,Ⅰ型胶原和Ⅲ型胶原蛋白的表达量分别增加13%和75%。此外,COE能够减轻UVB辐射引起的小鼠皮肤表皮增厚及胶原蛋白的丧失。同时,COE处理使丙二醛(malondialdehyde,MDA)含量降低69%,超氧化物歧化酶(superoxide dismutase,SOD)、谷胱甘肽过氧化物酶(clutathione peroxidase,GSH-Px)活性分别升高27%和234%。对小鼠表皮m RNA表达的分析表明,用COE处理导致Mmp1a和Mmp3 mRNA表达水平降低,Col1a1和Col3a1 m RNA水平升高。结论COE能够有效改善UVB辐射引起的皮肤损伤,其作用机制可能与抗氧化酶活性的增强以及促炎细胞因子和MMPs表达的抑制密切相关。本研究旨在通过小鼠和细胞模型进一步探究山茱萸对UVB诱导的皮肤损伤的光保护潜力并阐明其潜在机制,为治疗由UVB光老化导致皮肤疾病的研究和山茱萸新药开发提供理论依据。
文摘医学英语学习通常以教师为主导,教学方法较单一,学生大多在一种被动状态下学习,因缺乏学习兴趣和主动性而使教学效果不甚理想。笔者采用循序渐进的多元化教学模式,与某些基础医学学科和临床医学学科整合,为学生建立一个开放平台,让学生逐步了解将来可能的职业环境及如何设计相应的自学框架,在注重培养和提高医学英语应用能力的同时,注重学生自学等能力的培养,贯彻＂学会学习、边干边学、终身学习（learn to learn,learn by doing,life-longlearning）的教学理念，让学生在学习相关医学专业知识的实践中提高医学英语听、说、读、写及应对能力。
基金funded by Tackling Key Problems in Air Pollution Control Funding from Ministry of Science and Technology of the People’s Republic of China(DQGG0305-01)Chinese Academy of Medical Sciences(CAMS)Innovation Fund for Medical Sciences Program(2021-I2M-1-057)。
文摘Objectives To identify the 5'untranslated region of Zika virus(ZIKV 5'UTR)RNA-binding proteins and to investigate the impact of the binding protein on the activity of internal ribosomal entry site(IRES)located in ZIKV 5'UTR and virus production.Methods Interacting proteins in U251 cells were captured using tRSA-tagged ZIKV 5'UTR RNA and tRSA-ZIKV 5'UTR RNA-binding proteins were visualized by SDS-PAGE silver staining,Subsequently,liquid chromatographytandem mass spectrometry(LC-MS/MS),bioinformatics analysis,and Western blot were used to identify the candidate proteins binding to ZIKV 5'UTR.Dicistronic expression assay and plaque forming assay were performed to analyze the effect of the binding protein on ZIKV IRES activity and ZIKV production,respecitvely.Results tRSA RNA pull-down assay,LC-MS/MS,and Western blot analysis showed that polypyrimidine tractbinding protein(PTB)bound to the ZIKV 5'UTR.Furthermore,dual luciferase reporter assay revealed that overexpression of PTB significantly enhanced the IRES activity of ZIKV(t=10.220,P<0.001),while PTB knockdown had the opposite effect(t=4.897,P<0.01).Additionally,virus plaque forming assay demonstrated that up-regulation of PTB expression significantly enhanced viral titer(t=6.400,P<0.01),whereas reducing PTB expression level weakened virus infectivity(t=5.055,P<0.01).Conclusion PTB positively interacts with the ZIKV 5'UTR and enhances IRES activity and virus production.
