目的探索一种新的获取间充质干细胞(m esem chym al stem cells,MSCs)的来源及方法。MSCs在成人骨髓内含量极低,数量随着年龄的增长而减少。MSCs同时少量出现于外周血以及脐带血、胎儿组织器官内,然而,胎儿组织样本难以获取,脐带血中含...目的探索一种新的获取间充质干细胞(m esem chym al stem cells,MSCs)的来源及方法。MSCs在成人骨髓内含量极低,数量随着年龄的增长而减少。MSCs同时少量出现于外周血以及脐带血、胎儿组织器官内,然而,胎儿组织样本难以获取,脐带血中含量太低。这样,如何获得合适的MSCs来源以建立稳定的培养体系,同时避免伦理道德问题的约束是一个值得探索的课题。方法消化胎盘实体组织,贴壁培养细胞,观测形态并检测其细胞表面抗原表达以及分化潜能。结果胎盘组织中分离出的贴壁细胞与骨髓间充质干细胞有相似形态和细胞表面标志,具有分化为成骨细胞以及神经细胞的能力。结论胎盘组织中含有的多分化潜能细胞(p lacenta-derived mu ltipotent cells,PDMCs)与骨髓MSCs形态功能相似,胎盘可以作为获取MSCs的一种有效来源。展开更多
Objective:To explore the effects of dopamine receptor D2(DRD2)on astrocytic dedifferentiation based on SOX2-regulated genes in neural stem cells(NSCs)and astrocytes.Methods:Immunofluorescence staining and SOX2-GFP mic...Objective:To explore the effects of dopamine receptor D2(DRD2)on astrocytic dedifferentiation based on SOX2-regulated genes in neural stem cells(NSCs)and astrocytes.Methods:Immunofluorescence staining and SOX2-GFP mice were used to examine the lineage differentiation of SOX2-positive cells during the development of cerebral cortex.Primary NSCs/astrocytes culture,ChIP-seq and Western Blot were adopted to analyze and verify the expression of candidate genes.Pharmacological manipulation,neurosphere formation,photochemical ischemia,immunofluorescence staining and behavior tests were adopted to evaluate the effects of activating DRD2 signaling on astrocytic dedifferentiation.Results:Immunofluorescence staining demonstrated the NSC-astrocyte switch of SOX2-expression in the normal development of cerebral cortex.ChIP-seq revealed enrichment of DRD2 signaling by SOX2-bound enhancers in NSCs and SOX2-bound promoters in astrocytes.Western Blot and immunofluorescence staining verified the expression of DRD2 in NSCs and reactive astrocytes.Application of quinagolide hydrocholoride(QH),an agonist of DRD2,significantly promoted astrocytic dedifferentiation both in vitro and in vivo following ischemia.In addition,quinagolide hydrocholoride treatment improved locomotion recovery.Conclusion:Activating DRD2 signaling facilitates astrocytic dedifferentiation and may be used to treat ischemic stroke.展开更多
目的极小类胚胎干细胞(very small embryonic like stem cells,VSEL SCs)具有胚胎干细胞多分化潜能特性,理论上可以分化成各种细胞,因此可以将极小类胚胎干细胞体外定向诱导形成红细胞,为了获取体外生成红细胞的新来源,本研究建立了从...目的极小类胚胎干细胞(very small embryonic like stem cells,VSEL SCs)具有胚胎干细胞多分化潜能特性,理论上可以分化成各种细胞,因此可以将极小类胚胎干细胞体外定向诱导形成红细胞,为了获取体外生成红细胞的新来源,本研究建立了从人脐血中分离极小类胚胎干细胞的方法。方法脐带血标本与0.9%生理盐水以1∶1充分混匀,形成单细胞悬液层加到比重为1.077g/ml的淋巴细胞分离液上,经密度梯度离心收集单个核细胞层。应用Lineage Cell Depletion Kit从单个核细胞层中分选Lin阴性细胞,用CD45Mi-croBeads从中分选CD45阴性细胞,展开更多
The C–H bond activation in alkane dehydrogenation reactions is a key step in determining the reaction rate.To understand the impact of entropy,we performed ab initio static and molecular dynamics free energy simulati...The C–H bond activation in alkane dehydrogenation reactions is a key step in determining the reaction rate.To understand the impact of entropy,we performed ab initio static and molecular dynamics free energy simulations of ethane dehydrogenation over Co@BEA zeolite at different temperatures.AIMD simulations showed that a sharp decrease in free energy barrier as temperature increased.Our analysis of the temperature dependence of activation free energies uncovered an unusual entropic effect accompanying the reaction.The unique spatial structures around the Co active site at different temperatures influenced both the extent of charge transfer in the transition state and the arrangement of 3d orbital energy levels.We provided explanations consistent with the principles of thermodynamics and statistical physics.The insights gained at the atomic level have offered a fresh interpretation of the intricate long-range interplay between local chemical reactions and extensive chemical environments.展开更多
Genetic diversity and genetic differentiation of natural populations of Pinus kesiya var. langbinanensis were examined by means of electrophoresis technique. Analysis of 9 enzyme systems including 16 loci showed that ...Genetic diversity and genetic differentiation of natural populations of Pinus kesiya var. langbinanensis were examined by means of electrophoresis technique. Analysis of 9 enzyme systems including 16 loci showed that all the three natural popu-lations of the pine were high in genetic diversity but low in inter-population genetic differentiation. The proportion of polymorphic loci is 0.667, with each locus holding 2.13 alleles, averagely. The average expected and observed heterozygosity was 0.288 and 0.197, respectively. The gene differentiation among populations was 0.052, but the mean genetic distance was only 0.015.展开更多
文摘目的探索一种新的获取间充质干细胞(m esem chym al stem cells,MSCs)的来源及方法。MSCs在成人骨髓内含量极低,数量随着年龄的增长而减少。MSCs同时少量出现于外周血以及脐带血、胎儿组织器官内,然而,胎儿组织样本难以获取,脐带血中含量太低。这样,如何获得合适的MSCs来源以建立稳定的培养体系,同时避免伦理道德问题的约束是一个值得探索的课题。方法消化胎盘实体组织,贴壁培养细胞,观测形态并检测其细胞表面抗原表达以及分化潜能。结果胎盘组织中分离出的贴壁细胞与骨髓间充质干细胞有相似形态和细胞表面标志,具有分化为成骨细胞以及神经细胞的能力。结论胎盘组织中含有的多分化潜能细胞(p lacenta-derived mu ltipotent cells,PDMCs)与骨髓MSCs形态功能相似,胎盘可以作为获取MSCs的一种有效来源。
文摘Objective:To explore the effects of dopamine receptor D2(DRD2)on astrocytic dedifferentiation based on SOX2-regulated genes in neural stem cells(NSCs)and astrocytes.Methods:Immunofluorescence staining and SOX2-GFP mice were used to examine the lineage differentiation of SOX2-positive cells during the development of cerebral cortex.Primary NSCs/astrocytes culture,ChIP-seq and Western Blot were adopted to analyze and verify the expression of candidate genes.Pharmacological manipulation,neurosphere formation,photochemical ischemia,immunofluorescence staining and behavior tests were adopted to evaluate the effects of activating DRD2 signaling on astrocytic dedifferentiation.Results:Immunofluorescence staining demonstrated the NSC-astrocyte switch of SOX2-expression in the normal development of cerebral cortex.ChIP-seq revealed enrichment of DRD2 signaling by SOX2-bound enhancers in NSCs and SOX2-bound promoters in astrocytes.Western Blot and immunofluorescence staining verified the expression of DRD2 in NSCs and reactive astrocytes.Application of quinagolide hydrocholoride(QH),an agonist of DRD2,significantly promoted astrocytic dedifferentiation both in vitro and in vivo following ischemia.In addition,quinagolide hydrocholoride treatment improved locomotion recovery.Conclusion:Activating DRD2 signaling facilitates astrocytic dedifferentiation and may be used to treat ischemic stroke.
文摘目的极小类胚胎干细胞(very small embryonic like stem cells,VSEL SCs)具有胚胎干细胞多分化潜能特性,理论上可以分化成各种细胞,因此可以将极小类胚胎干细胞体外定向诱导形成红细胞,为了获取体外生成红细胞的新来源,本研究建立了从人脐血中分离极小类胚胎干细胞的方法。方法脐带血标本与0.9%生理盐水以1∶1充分混匀,形成单细胞悬液层加到比重为1.077g/ml的淋巴细胞分离液上,经密度梯度离心收集单个核细胞层。应用Lineage Cell Depletion Kit从单个核细胞层中分选Lin阴性细胞,用CD45Mi-croBeads从中分选CD45阴性细胞,
文摘The C–H bond activation in alkane dehydrogenation reactions is a key step in determining the reaction rate.To understand the impact of entropy,we performed ab initio static and molecular dynamics free energy simulations of ethane dehydrogenation over Co@BEA zeolite at different temperatures.AIMD simulations showed that a sharp decrease in free energy barrier as temperature increased.Our analysis of the temperature dependence of activation free energies uncovered an unusual entropic effect accompanying the reaction.The unique spatial structures around the Co active site at different temperatures influenced both the extent of charge transfer in the transition state and the arrangement of 3d orbital energy levels.We provided explanations consistent with the principles of thermodynamics and statistical physics.The insights gained at the atomic level have offered a fresh interpretation of the intricate long-range interplay between local chemical reactions and extensive chemical environments.
基金his article was supported by the Natural Science Founda-tion of Yunnan Province (No.98C017Q).
文摘Genetic diversity and genetic differentiation of natural populations of Pinus kesiya var. langbinanensis were examined by means of electrophoresis technique. Analysis of 9 enzyme systems including 16 loci showed that all the three natural popu-lations of the pine were high in genetic diversity but low in inter-population genetic differentiation. The proportion of polymorphic loci is 0.667, with each locus holding 2.13 alleles, averagely. The average expected and observed heterozygosity was 0.288 and 0.197, respectively. The gene differentiation among populations was 0.052, but the mean genetic distance was only 0.015.
