作为一种广谱表达的细胞粘附分子,Ⅰ型跨膜糖蛋白CD44(cluster of differentiation 44)参与细胞增殖、分化、迁移,血管生成等生物学过程,对于介导细胞信号转导,调节组织稳态等功能具有关键作用.特别地,CD44-选择素、CD44-透明质酸相互...作为一种广谱表达的细胞粘附分子,Ⅰ型跨膜糖蛋白CD44(cluster of differentiation 44)参与细胞增殖、分化、迁移,血管生成等生物学过程,对于介导细胞信号转导,调节组织稳态等功能具有关键作用.特别地,CD44-选择素、CD44-透明质酸相互作用介导的细胞粘附动力学在经典炎症反应、肿瘤转移或组织特异的肝脏免疫中具有重要作用.该综述分别从细胞层次粘附动力学、二维与三维条件下的分子层次反应动力学、原子层次微观结构以及胞内信号转导通路等方面综述了CD44-选择素、CD44-透明质酸相互作用的研究进展及尚待回答的生物力学问题.力学、物理因素对生命活动的不可或缺性逐渐被研究者们接受,力学医学、力学免疫学、力学组学等新概念相继提出.生理、病理条件下,CD44-配体相互作用介导的细胞粘附必将受到血流剪切、基底硬度等力学、物理微环境的调控,但是其调控机制还远不清楚.基于此,本文就CD44-配体相互作用相关的未来研究方向做出展望,主要包括:力学、物理因素如何调控CD44-配体相互作用介导的细胞粘附动力学及其内在机制;CD44-配体相互作用反应动力学的力学调控规律及结构基础是什么;以及力学作用下CD44-配体相互作用原子层次的微观结构如何发生动态演化.本文可为深入理解CD44-配体相互作用的生物学功能及其结构功能关系提供线索.展开更多
LFA-1 and Mac-1, two β2integrin members constitutively expressed on neutrophils, mediate leukocyte recruitment cascade by binding to the same ligand of ICAM-1. The slow rolling and firm adhesion of leukocytes rely on...LFA-1 and Mac-1, two β2integrin members constitutively expressed on neutrophils, mediate leukocyte recruitment cascade by binding to the same ligand of ICAM-1. The slow rolling and firm adhesion of leukocytes rely on LFA-1 while the cell crawling is dependent on Mac-1. We hypothesized that their distinct roles were likely attributed to the differences in the binding kinetics or in the diverse responses of outside-in and inside-out signaling. In this study, we compared the ICAM-1 binding features between soluble or membrane-expressed LFA-1 and Mac-1 with different affinity conformations using optical trap technique. Our data indicate that the affinity up-regulation from wide type(WT) to high affinity(HA) is off-rate dependent for LFA-1but on-rate dependent for Mac-1. The structural bases of this new finding were found to be consistent with our previous simulations. These results furthered our understanding on their function differences under shear flow.展开更多
Advances of microgravity sciences in China are introduced. The research works include ground-based study and space experiments. In the recent years, the main means still are theoretical analysis, numerical simulation,...Advances of microgravity sciences in China are introduced. The research works include ground-based study and space experiments. In the recent years, the main means still are theoretical analysis, numerical simulation, ground-based experiment, and short-time microgravity experiments of drop tower. Besides, many space experiment projects are arranged. SJ-10 recoverable satellite will carry out 19 scientific experiment projects. Nine of them are for microgravity Sciences. The other ways for space microgravity experiment are with the help of Chinese Shenzhou spacecraft, Chinese Tiangong space laboratory, and Chinese space station in the near future. The Chinese space station will become main platform of Chinese microgravity sciences experiment in space.展开更多
With the human space exploration activities, space life science is an emerging interdiscipline,which covers a wide range of researches. Based on our country's manned space station and recoverable satellite science...With the human space exploration activities, space life science is an emerging interdiscipline,which covers a wide range of researches. Based on our country's manned space station and recoverable satellite science experimental platform, the development of space life science research is very important to acquire new knowledge or new technological innovation, to give further services to the human space exploration activities,to improve the national economic and social development. Both ground-based and flight applied studies were continuously performed in the previous 2 years. Here, we review and summarize the researches on space life sciences contributed by Chinese scientists.展开更多
Recent progresses in 2018–2019 from space experiments onboard SJ-10 recoverable satellite and on parabolic flight were summarized,mainly focusing on cell mechano-biological coupling under microgravity.In the meantime...Recent progresses in 2018–2019 from space experiments onboard SJ-10 recoverable satellite and on parabolic flight were summarized,mainly focusing on cell mechano-biological coupling under microgravity.In the meantime,technical pre-research and experimental system design for the biomechanics research platform on China Space Station was carried out and updated.展开更多
SJ-10 is a recoverable scientific experiment satellite specially for the space experiments of microgravity physics science and space life science.This mission was officially started on 31 December 2012,and the satelli...SJ-10 is a recoverable scientific experiment satellite specially for the space experiments of microgravity physics science and space life science.This mission was officially started on 31 December 2012,and the satellite was launched on 6 April 2016.This paper introduces briefly the SJ-10 mission,the progress of SJ-10 engineering and the project constitution of sciences experiments onboard SJ-10.The purpose of this mission is to discover the law of matter movement and the rule of life activity that cannot be discovered on the ground due to the existence of gravity,and to know the acting mechanism on organisms by the complex radiation of space that cannot be simulated on the ground.展开更多
In the past two years,China’s space life science has made great progress.Space biomedical and life science programs have carried out ground-based research for the first batch of projects,and are preparing to carry ou...In the past two years,China’s space life science has made great progress.Space biomedical and life science programs have carried out ground-based research for the first batch of projects,and are preparing to carry out space-based experiments along with the construction of China’s space station.And space life science payload of the space station completed the development of positive samples.Thus,with the development of lunar exploration and Mars exploration projects,astrobiology research has also made a lot of basic achievements.On the basis of summarizing the development of space life science in China,this paper mainly introduces the important progress of payload technology and life science research.展开更多
Microgravity fluid physics is an important part of microgravity sciences, which consists of simple fluids of many new systems, gas-liquid two-phase flow and heat transfer, and complex fluid mechanics. In addition to t...Microgravity fluid physics is an important part of microgravity sciences, which consists of simple fluids of many new systems, gas-liquid two-phase flow and heat transfer, and complex fluid mechanics. In addition to the importance of itself in sciences and applications, microgravity fluid physics closely relates to microgravity combustion, space biotechnology and space materials science, and promotes the developments of interdisciplinary fields. Many space microgravity experiments have been performed on board the recoverable satellites and space ships of China and pushed the rapid development of microgravity sciences in China. In the present paper, space experimental studies and the main results of the microgravity fluid science in China in the last 10 years or so are introduced briefly.展开更多
Neutrophil (PMN) spreading on endothelium, mediated by the interactions between surface-bound β2 integrin and intercellular adhesion molecule-1 (ICAM-1) in the inflammatory cascade, is crucial for PMN post-adhesion a...Neutrophil (PMN) spreading on endothelium, mediated by the interactions between surface-bound β2 integrin and intercellular adhesion molecule-1 (ICAM-1) in the inflammatory cascade, is crucial for PMN post-adhesion and trans-migration in blood flow. The underlying mechanisms by which shear flow regulates PMN spreading dynamics are not well understood. Here, a parallel-plate flow chamber assay was applied to quantify the time course of PMN adhesion and spreading on an ICAM-1-immobilized substrate. Two types of shear flow, steady flows at shear stresses of 0.2, 0.5, and 1 dyne/cm2 and stepwise flows at 0, 1, and 10 dyne/cm2, were used to elucidate the impact of shear flow on cell adhesion and spreading. The number of adhered PMNs, the fraction of spreading PMNs and the projected area of spread PMNs were determined and were found to correlate with the distribution of surface-bound β2 integrin subunit (CD11a, CD11b, or CD18). The results indicate that PMN spreading on an ICAM-1 substrate is bi-directionally regulated under shear flow. CD11a, CD11b and CD18 subunits of β2 integrin contribute distinctly to PMN spreading on ICAM-1 substrates. This work provides new insights into understanding PMN spreading on the endothelium, mediated by β2 integrin and ICAM-1 under shear flow.展开更多
LFA-1 and Mac-l, two $2 integrin members constitutively expressed on neutrophils, mediate leukocyte recruitment cascade by binding to the same ligand of ICAM-1. The slow rolling and firm adhesion of leukocytes rely on...LFA-1 and Mac-l, two $2 integrin members constitutively expressed on neutrophils, mediate leukocyte recruitment cascade by binding to the same ligand of ICAM-1. The slow rolling and firm adhesion of leukocytes rely on LFA-1 while the cell crawling is dependent on Mac-1. We hypothesized that their distinct roles are likely attributed to the differences in the binding kinetics or in the diverse responses of outside-in and inside-out signaling. In this study, we compared the ICAM-1 binding features between soluble or membrane-expressed LFA-1 and Mac-1 with different affinity conformation using optical trap technique. Our data indicated that the affinity up-regulation from wide type （WT） to high affinity （HA） is off-rate dependent for LFA-1 but on-rate dependent for Mac-1. The structural bases of this new finding were found to be consistent with our previous simulations. These results furthered our understanding in their function differences under shear flow.展开更多
文摘作为一种广谱表达的细胞粘附分子,Ⅰ型跨膜糖蛋白CD44(cluster of differentiation 44)参与细胞增殖、分化、迁移,血管生成等生物学过程,对于介导细胞信号转导,调节组织稳态等功能具有关键作用.特别地,CD44-选择素、CD44-透明质酸相互作用介导的细胞粘附动力学在经典炎症反应、肿瘤转移或组织特异的肝脏免疫中具有重要作用.该综述分别从细胞层次粘附动力学、二维与三维条件下的分子层次反应动力学、原子层次微观结构以及胞内信号转导通路等方面综述了CD44-选择素、CD44-透明质酸相互作用的研究进展及尚待回答的生物力学问题.力学、物理因素对生命活动的不可或缺性逐渐被研究者们接受,力学医学、力学免疫学、力学组学等新概念相继提出.生理、病理条件下,CD44-配体相互作用介导的细胞粘附必将受到血流剪切、基底硬度等力学、物理微环境的调控,但是其调控机制还远不清楚.基于此,本文就CD44-配体相互作用相关的未来研究方向做出展望,主要包括:力学、物理因素如何调控CD44-配体相互作用介导的细胞粘附动力学及其内在机制;CD44-配体相互作用反应动力学的力学调控规律及结构基础是什么;以及力学作用下CD44-配体相互作用原子层次的微观结构如何发生动态演化.本文可为深入理解CD44-配体相互作用的生物学功能及其结构功能关系提供线索.
基金National Natural Science Foundation of Chinagrant number:30730032,11072251+1 种基金National Key Basic Research Foundation of Chinagrant number:2011CB710904
文摘LFA-1 and Mac-1, two β2integrin members constitutively expressed on neutrophils, mediate leukocyte recruitment cascade by binding to the same ligand of ICAM-1. The slow rolling and firm adhesion of leukocytes rely on LFA-1 while the cell crawling is dependent on Mac-1. We hypothesized that their distinct roles were likely attributed to the differences in the binding kinetics or in the diverse responses of outside-in and inside-out signaling. In this study, we compared the ICAM-1 binding features between soluble or membrane-expressed LFA-1 and Mac-1 with different affinity conformations using optical trap technique. Our data indicate that the affinity up-regulation from wide type(WT) to high affinity(HA) is off-rate dependent for LFA-1but on-rate dependent for Mac-1. The structural bases of this new finding were found to be consistent with our previous simulations. These results furthered our understanding on their function differences under shear flow.
文摘Advances of microgravity sciences in China are introduced. The research works include ground-based study and space experiments. In the recent years, the main means still are theoretical analysis, numerical simulation, ground-based experiment, and short-time microgravity experiments of drop tower. Besides, many space experiment projects are arranged. SJ-10 recoverable satellite will carry out 19 scientific experiment projects. Nine of them are for microgravity Sciences. The other ways for space microgravity experiment are with the help of Chinese Shenzhou spacecraft, Chinese Tiangong space laboratory, and Chinese space station in the near future. The Chinese space station will become main platform of Chinese microgravity sciences experiment in space.
文摘With the human space exploration activities, space life science is an emerging interdiscipline,which covers a wide range of researches. Based on our country's manned space station and recoverable satellite science experimental platform, the development of space life science research is very important to acquire new knowledge or new technological innovation, to give further services to the human space exploration activities,to improve the national economic and social development. Both ground-based and flight applied studies were continuously performed in the previous 2 years. Here, we review and summarize the researches on space life sciences contributed by Chinese scientists.
基金Supported by Strategic Priority Research Program and Frontier Science Key Project of Chinese Academy of Sciences(XDA04020202-17,XDA04020416,XDA15014100QYZDJSSW-JSC018),National Natural Science Foundation of China(U1738115)。
文摘Recent progresses in 2018–2019 from space experiments onboard SJ-10 recoverable satellite and on parabolic flight were summarized,mainly focusing on cell mechano-biological coupling under microgravity.In the meantime,technical pre-research and experimental system design for the biomechanics research platform on China Space Station was carried out and updated.
基金Supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA04020000)United Funding from National Natural Science Foundation of China and Chinese Academy of Sciences。
文摘SJ-10 is a recoverable scientific experiment satellite specially for the space experiments of microgravity physics science and space life science.This mission was officially started on 31 December 2012,and the satellite was launched on 6 April 2016.This paper introduces briefly the SJ-10 mission,the progress of SJ-10 engineering and the project constitution of sciences experiments onboard SJ-10.The purpose of this mission is to discover the law of matter movement and the rule of life activity that cannot be discovered on the ground due to the existence of gravity,and to know the acting mechanism on organisms by the complex radiation of space that cannot be simulated on the ground.
基金Supported by Space Medical Experiment Project of China Manned Space Program(HYZHXM02003)。
文摘In the past two years,China’s space life science has made great progress.Space biomedical and life science programs have carried out ground-based research for the first batch of projects,and are preparing to carry out space-based experiments along with the construction of China’s space station.And space life science payload of the space station completed the development of positive samples.Thus,with the development of lunar exploration and Mars exploration projects,astrobiology research has also made a lot of basic achievements.On the basis of summarizing the development of space life science in China,this paper mainly introduces the important progress of payload technology and life science research.
基金Supported by the Knowledge Innovation Project of the Chinese Academy of Sci-ences (Grant No. KJCX2-L08)National Natural Science Foundation of China (Grant Nos. 10872202, 10672171 and 30730032)
文摘Microgravity fluid physics is an important part of microgravity sciences, which consists of simple fluids of many new systems, gas-liquid two-phase flow and heat transfer, and complex fluid mechanics. In addition to the importance of itself in sciences and applications, microgravity fluid physics closely relates to microgravity combustion, space biotechnology and space materials science, and promotes the developments of interdisciplinary fields. Many space microgravity experiments have been performed on board the recoverable satellites and space ships of China and pushed the rapid development of microgravity sciences in China. In the present paper, space experimental studies and the main results of the microgravity fluid science in China in the last 10 years or so are introduced briefly.
基金supported by the National Natural Science Foundation of China (30730032 and 10902117)Chinese Academy of Sciences Knowledge Innovation Project (KJCX2-YW-L08 and Y2010030)the National Basic Research Program of China (2011CB710904)
文摘Neutrophil (PMN) spreading on endothelium, mediated by the interactions between surface-bound β2 integrin and intercellular adhesion molecule-1 (ICAM-1) in the inflammatory cascade, is crucial for PMN post-adhesion and trans-migration in blood flow. The underlying mechanisms by which shear flow regulates PMN spreading dynamics are not well understood. Here, a parallel-plate flow chamber assay was applied to quantify the time course of PMN adhesion and spreading on an ICAM-1-immobilized substrate. Two types of shear flow, steady flows at shear stresses of 0.2, 0.5, and 1 dyne/cm2 and stepwise flows at 0, 1, and 10 dyne/cm2, were used to elucidate the impact of shear flow on cell adhesion and spreading. The number of adhered PMNs, the fraction of spreading PMNs and the projected area of spread PMNs were determined and were found to correlate with the distribution of surface-bound β2 integrin subunit (CD11a, CD11b, or CD18). The results indicate that PMN spreading on an ICAM-1 substrate is bi-directionally regulated under shear flow. CD11a, CD11b and CD18 subunits of β2 integrin contribute distinctly to PMN spreading on ICAM-1 substrates. This work provides new insights into understanding PMN spreading on the endothelium, mediated by β2 integrin and ICAM-1 under shear flow.
文摘LFA-1 and Mac-l, two $2 integrin members constitutively expressed on neutrophils, mediate leukocyte recruitment cascade by binding to the same ligand of ICAM-1. The slow rolling and firm adhesion of leukocytes rely on LFA-1 while the cell crawling is dependent on Mac-1. We hypothesized that their distinct roles are likely attributed to the differences in the binding kinetics or in the diverse responses of outside-in and inside-out signaling. In this study, we compared the ICAM-1 binding features between soluble or membrane-expressed LFA-1 and Mac-1 with different affinity conformation using optical trap technique. Our data indicated that the affinity up-regulation from wide type （WT） to high affinity （HA） is off-rate dependent for LFA-1 but on-rate dependent for Mac-1. The structural bases of this new finding were found to be consistent with our previous simulations. These results furthered our understanding in their function differences under shear flow.
