目的探讨4 d头低位卧床(head-down bed rest,HDBR)模拟失重对人体运动能力的影响及人工重力联合中等强度运动锻炼的对抗效果。方法 12名健康男性志愿者随机分为2组:对照组(n=6)仅进行4 d HDBR;对抗组(n=6)HDBR期间每天上下午各进行1次30...目的探讨4 d头低位卧床(head-down bed rest,HDBR)模拟失重对人体运动能力的影响及人工重力联合中等强度运动锻炼的对抗效果。方法 12名健康男性志愿者随机分为2组:对照组(n=6)仅进行4 d HDBR;对抗组(n=6)HDBR期间每天上下午各进行1次30 min基于人工重力(足水平2 Gz)的中等强度运动锻炼。HDBR前后对所有志愿者分别进行有氧和无氧运动能力测试。结果 HDBR后对照组递增负荷累计运动应激指数、最大摄氧量、无氧阈及30 s最大负荷运动中的最小无氧功较卧床前均显著下降(P<0.05),无氧功递减率显著升高(P<0.05)而无氧功峰值、平均无氧功均无显著改变;HDBR后对抗组上述各项指标均无显著改变。结论 4 d HDBR可致人体运动能力下降,其中对有氧运动能力影响最大,对无氧运动能力影响较小。基于人工重力的中等强度运动锻炼可有效对抗模拟失重所致的有氧及无氧运动耐力下降。展开更多
Spaceflight and ground-based microgravity analog experiments have suggested that microgravity can affect microbial growth and metabolism. Although the effects of microgravity and its analogs on microorganisms have bee...Spaceflight and ground-based microgravity analog experiments have suggested that microgravity can affect microbial growth and metabolism. Although the effects of microgravity and its analogs on microorganisms have been studied for more than 50 years, plausible conflicting and diverse results have frequently been reported in different experiments, especially regarding microbial growth and secondary metabolism. Until now, only the responses of a few typical microbes to microgravity have been investigated; systematic studies of the genetic and phenotypic responses of these microorganisms to microgravity in space are still insufficient due to technological and logistical hurdles. The use of different test strains and secondary metabolites in these studies appears to have caused diverse and conflicting results. Moreover, subtle changes in the extracellular microenvironments around microbial cells play a key role in the diverse responses of microbial growth and secondary metabolisms. Therefore, "indirect" effects represent a reasonable pathway to explain the occurrence of these phenomena in microorganisms. This review summarizes current knowledge on the changes in microbial growth and secondary metabolism in response to spaceflight and its analogs and discusses the diverse and conflicting results. In addition, recommendations are given for future studies on the effects of microgravity in space on microbial growth and secondary metabolism.展开更多
Bone-formation related gene plays a critical role in bone loss induced by space mi-crogravity, however the exact mechanism is unclear. In this study, we aim to investigate the effect of microgravity on the activity of...Bone-formation related gene plays a critical role in bone loss induced by space mi-crogravity, however the exact mechanism is unclear. In this study, we aim to investigate the effect of microgravity on the activity of ?1(I) collagen (COL1A1) gene promoter and the expression of osteoblast-related genes. COL1A1 promoter was digested by restriction enzymes resulting in three DNA fragments. The fragments were ligated with the enhanced green fluorescent protein report gene, and subcloned into expression vectors. ROS17/2.8 cells transfected by these vec-tors were screened by G418, and enhanced green fluorescent protein (EGFP) positive colonies were isolated and cultured under clinostat condition. EGFP and Collagen type I expression level were detected by fluorescence intensity analysis and immunocytochemistry methods respectively. The results showed that the expression of EGFP and collagen type I was increased 24 h, 48 h after the cells were cultured under stimulated microgravity, illustrating that the activity of COL1A1 promoter might be increased. In conclusion, osteoblasts can compensatively increase the ex-pression of type I collagen by enhancing the activity of COL1A1 promoter under short-term simulated microgravity conditions.展开更多
Objective To investigate the effect of simulated microgravity and carbon ion irradiation （CIR） on spermatogenic cell apoptosis and sperm DNA damage to the testis of male Swiss Webster mice, and assess the risk assoc...Objective To investigate the effect of simulated microgravity and carbon ion irradiation （CIR） on spermatogenic cell apoptosis and sperm DNA damage to the testis of male Swiss Webster mice, and assess the risk associated with space environment. Methods Sperm DNA damage indicated by DNA fragmentation index （DFI） and high DNA stainability （HDS） was measured by sperm chromatin structure assay （SCSA）. Apoptosis of spermatogenic cells was detected by annexin V-propidium iodide assay. Bax （the expression levels of p53） and proliferating cell nuclear antigen （PCNAI were measured by immunoblotting; p53 and PCNA were located by immunohistology. Results HDS, DFI, apoptosis index, and the expression levels of p53 and Bax were detected to be significantly higher in the experimental groups （P〈0.05） compared with those in the control group, however, the PCNA expression varied to a certain degree, p53- and PCNA- positive expression were detected in each group, mainly in relation to the spermatogonic cells and spermatocytes. Conclusion The findings of the present study demonstrated that simulated microgravity and CIR can induce spermatogenic cell apoptosis and sperm DNA damage. Sperm DNA damage may be one of the underlying mechanisms behind male fertility decline under space environment. These findings may provide a scientific basis for protectint~ astronauts and space traveler＇s health and safety.展开更多
Mesenchymal stem cells （MSCs） were induced into a nucleus pulposus-like phenotype utilizing simulated microgravity in vitro in order to establish a new cell-based tissue engineering treatment for intervertebral disc...Mesenchymal stem cells （MSCs） were induced into a nucleus pulposus-like phenotype utilizing simulated microgravity in vitro in order to establish a new cell-based tissue engineering treatment for intervertebral disc degeneration. For induction of a nucleus pulposus-like phenotype, MSCs were cultured in simulated microgravity in a chemically defined medium supplemented with 0 （experimental group） and 10 ng/mL （positive control group） of transforming growth factor β1 （TGF-β1）. MSCs cultured under conventional condition without TGF-β1 served as blank control group. On the day 3 of culture, cellular proliferation was determined by WST-8 assay. Differentiation markers were evaluated by histology and reverse transcriptase-polymerase chain reaction （RT-PCR）. TGF-β1 slightly promoted the proliferation of MSCs. The collagen and proteoglycans were detected in both groups after culture for 7 days. The accumulation of proteoglycans was markedly increased. The RT-PCR revealed that the gene expression of Sox-9, aggrecan and type Ⅱ collagen, which were chondrocyte specific, was increased in MSCs cultured under simulated microgravity for 3 days. The ratio of proteoglycans/collagen in blank control group was 3.4-fold higher than positive control group, which denoted a nucleus pulposus-like phenotype differentiation. Independent, spontaneous differentiation of MSCs towards a nucleus pulposus-like phenotype in simulated microgravity occurred without addition of any external bioactive stimulators, namely factors from TGF-β family, which were previously considered necessary.展开更多
Astronauts are under high stress for a long time because of the microgravity condition,which leads to anxiety,affects their learning and memory abilities,and seriously impairs the health of astronauts.Aromatherapy can...Astronauts are under high stress for a long time because of the microgravity condition,which leads to anxiety,affects their learning and memory abilities,and seriously impairs the health of astronauts.Aromatherapy can improve the physical and mental health of astronauts in a way that moisturizes them softly and silently.However,the strong volatility of fragrances and inconvenience of aroma treatment greatly limit their application in the field of spaceflight.In this study,reactive mesoporous silica nanoparticles were prepared to encapsulate and slowly release limonene.The limonene loaded nanoparticles were named limonene@mesoporous silica nanoparticles-cyanuric chloride(LE@MSNs-CYC).LE@MSNs-CYC were then applied to wallpaper to improve the convenience of aromatherapy.LE@MSNs-CYC could chemically react with the wallpaper,thus firmly adsorbed on the wallpaper.In the following,the mice were treated with hindlimb unloading(HU)to simulate a microgravity environment.The results showed that 28-day HU led to an increase in the level of anxiety and declines in learning,memory,and physical health in mice.LE@MSNs-CYC showed significant relief effects on anxiety,learning,memory,and physical health of HU treated mice.Subsequently,the molecular mechanisms were explored by hypothalamic-pituitary-adrenal axis related hormones,immune-related cytokines,learning,and memory-related neurotransmitters and proteins.展开更多
The depression of cardiac contractility induced by space microgravity is an important issue of aerospace medicine research, while its precise mechanism is still unknown. In the present study, we explored effects of si...The depression of cardiac contractility induced by space microgravity is an important issue of aerospace medicine research, while its precise mechanism is still unknown. In the present study, we explored effects of simulated microgravity on nitric oxide (NO) level, inducible nitric oxide synthase (iNOS) expression and related regulative mechanism using electron spin resonance (ESR) spectroscopy, immunocytochemistry and in situ hybridization. We found a remarkable in-crease of NO level and up-regulation of iNOS and iNOS mRNA expression in rat cardiac myocytes under simulated microgravity. Staurosporine (a nonselective protein kinase inhibitor), calphostin C (a selective protein kinase C inhibitor), partially inhibited the effect of simulated microgravity. Thus regulative effect of simulated microgravity on iNOS expression is mediated at least partially via activation of protein kinase C. These results indicate that NO system in cardiac myocytes is sensi-tive to simulated microgravity and may play an important role in the depression of cardiac contrac-tility induced by simulated microgravity.展开更多
文摘目的探讨4 d头低位卧床(head-down bed rest,HDBR)模拟失重对人体运动能力的影响及人工重力联合中等强度运动锻炼的对抗效果。方法 12名健康男性志愿者随机分为2组:对照组(n=6)仅进行4 d HDBR;对抗组(n=6)HDBR期间每天上下午各进行1次30 min基于人工重力(足水平2 Gz)的中等强度运动锻炼。HDBR前后对所有志愿者分别进行有氧和无氧运动能力测试。结果 HDBR后对照组递增负荷累计运动应激指数、最大摄氧量、无氧阈及30 s最大负荷运动中的最小无氧功较卧床前均显著下降(P<0.05),无氧功递减率显著升高(P<0.05)而无氧功峰值、平均无氧功均无显著改变;HDBR后对抗组上述各项指标均无显著改变。结论 4 d HDBR可致人体运动能力下降,其中对有氧运动能力影响最大,对无氧运动能力影响较小。基于人工重力的中等强度运动锻炼可有效对抗模拟失重所致的有氧及无氧运动耐力下降。
基金supported by the China Manned Space Engineering Program(CMSE,921–2)the National Program on Key Basic Research Project(973 Program,No.2014CB744400)the General Financial Grant from the China Postdoctoral Science Foundation(No.2016 M602971)
文摘Spaceflight and ground-based microgravity analog experiments have suggested that microgravity can affect microbial growth and metabolism. Although the effects of microgravity and its analogs on microorganisms have been studied for more than 50 years, plausible conflicting and diverse results have frequently been reported in different experiments, especially regarding microbial growth and secondary metabolism. Until now, only the responses of a few typical microbes to microgravity have been investigated; systematic studies of the genetic and phenotypic responses of these microorganisms to microgravity in space are still insufficient due to technological and logistical hurdles. The use of different test strains and secondary metabolites in these studies appears to have caused diverse and conflicting results. Moreover, subtle changes in the extracellular microenvironments around microbial cells play a key role in the diverse responses of microbial growth and secondary metabolisms. Therefore, "indirect" effects represent a reasonable pathway to explain the occurrence of these phenomena in microorganisms. This review summarizes current knowledge on the changes in microbial growth and secondary metabolism in response to spaceflight and its analogs and discusses the diverse and conflicting results. In addition, recommendations are given for future studies on the effects of microgravity in space on microbial growth and secondary metabolism.
文摘Bone-formation related gene plays a critical role in bone loss induced by space mi-crogravity, however the exact mechanism is unclear. In this study, we aim to investigate the effect of microgravity on the activity of ?1(I) collagen (COL1A1) gene promoter and the expression of osteoblast-related genes. COL1A1 promoter was digested by restriction enzymes resulting in three DNA fragments. The fragments were ligated with the enhanced green fluorescent protein report gene, and subcloned into expression vectors. ROS17/2.8 cells transfected by these vec-tors were screened by G418, and enhanced green fluorescent protein (EGFP) positive colonies were isolated and cultured under clinostat condition. EGFP and Collagen type I expression level were detected by fluorescence intensity analysis and immunocytochemistry methods respectively. The results showed that the expression of EGFP and collagen type I was increased 24 h, 48 h after the cells were cultured under stimulated microgravity, illustrating that the activity of COL1A1 promoter might be increased. In conclusion, osteoblasts can compensatively increase the ex-pression of type I collagen by enhancing the activity of COL1A1 promoter under short-term simulated microgravity conditions.
基金supported by the Knowledge Innovation Project of the Chinese Academy of Sciences(KJCX2-YW-L08)the National Basic Research Program of China(2010CB834202)+1 种基金the National Natural Science Foundation of China(10835011)the Scientific Technology Research Projects of Gansu Province(0702NKDA045,0806RJYA020)
文摘Objective To investigate the effect of simulated microgravity and carbon ion irradiation （CIR） on spermatogenic cell apoptosis and sperm DNA damage to the testis of male Swiss Webster mice, and assess the risk associated with space environment. Methods Sperm DNA damage indicated by DNA fragmentation index （DFI） and high DNA stainability （HDS） was measured by sperm chromatin structure assay （SCSA）. Apoptosis of spermatogenic cells was detected by annexin V-propidium iodide assay. Bax （the expression levels of p53） and proliferating cell nuclear antigen （PCNAI were measured by immunoblotting; p53 and PCNA were located by immunohistology. Results HDS, DFI, apoptosis index, and the expression levels of p53 and Bax were detected to be significantly higher in the experimental groups （P〈0.05） compared with those in the control group, however, the PCNA expression varied to a certain degree, p53- and PCNA- positive expression were detected in each group, mainly in relation to the spermatogonic cells and spermatocytes. Conclusion The findings of the present study demonstrated that simulated microgravity and CIR can induce spermatogenic cell apoptosis and sperm DNA damage. Sperm DNA damage may be one of the underlying mechanisms behind male fertility decline under space environment. These findings may provide a scientific basis for protectint~ astronauts and space traveler＇s health and safety.
基金supported by grants from the National Natural Sciences Foundation of China (No. 30772206 &10925208)
文摘Mesenchymal stem cells （MSCs） were induced into a nucleus pulposus-like phenotype utilizing simulated microgravity in vitro in order to establish a new cell-based tissue engineering treatment for intervertebral disc degeneration. For induction of a nucleus pulposus-like phenotype, MSCs were cultured in simulated microgravity in a chemically defined medium supplemented with 0 （experimental group） and 10 ng/mL （positive control group） of transforming growth factor β1 （TGF-β1）. MSCs cultured under conventional condition without TGF-β1 served as blank control group. On the day 3 of culture, cellular proliferation was determined by WST-8 assay. Differentiation markers were evaluated by histology and reverse transcriptase-polymerase chain reaction （RT-PCR）. TGF-β1 slightly promoted the proliferation of MSCs. The collagen and proteoglycans were detected in both groups after culture for 7 days. The accumulation of proteoglycans was markedly increased. The RT-PCR revealed that the gene expression of Sox-9, aggrecan and type Ⅱ collagen, which were chondrocyte specific, was increased in MSCs cultured under simulated microgravity for 3 days. The ratio of proteoglycans/collagen in blank control group was 3.4-fold higher than positive control group, which denoted a nucleus pulposus-like phenotype differentiation. Independent, spontaneous differentiation of MSCs towards a nucleus pulposus-like phenotype in simulated microgravity occurred without addition of any external bioactive stimulators, namely factors from TGF-β family, which were previously considered necessary.
基金financially supported by the National High Technology Research and Development Program(2016YFA0200303)the Beijing Natural Science Foundation(L172046,2192057)the National Natural Science Foundation of China(31771095,21875254 , 21905283).
文摘Astronauts are under high stress for a long time because of the microgravity condition,which leads to anxiety,affects their learning and memory abilities,and seriously impairs the health of astronauts.Aromatherapy can improve the physical and mental health of astronauts in a way that moisturizes them softly and silently.However,the strong volatility of fragrances and inconvenience of aroma treatment greatly limit their application in the field of spaceflight.In this study,reactive mesoporous silica nanoparticles were prepared to encapsulate and slowly release limonene.The limonene loaded nanoparticles were named limonene@mesoporous silica nanoparticles-cyanuric chloride(LE@MSNs-CYC).LE@MSNs-CYC were then applied to wallpaper to improve the convenience of aromatherapy.LE@MSNs-CYC could chemically react with the wallpaper,thus firmly adsorbed on the wallpaper.In the following,the mice were treated with hindlimb unloading(HU)to simulate a microgravity environment.The results showed that 28-day HU led to an increase in the level of anxiety and declines in learning,memory,and physical health in mice.LE@MSNs-CYC showed significant relief effects on anxiety,learning,memory,and physical health of HU treated mice.Subsequently,the molecular mechanisms were explored by hypothalamic-pituitary-adrenal axis related hormones,immune-related cytokines,learning,and memory-related neurotransmitters and proteins.
基金supported by National Plan of High-Tech Research and Development(863-2-2-2-4).
文摘The depression of cardiac contractility induced by space microgravity is an important issue of aerospace medicine research, while its precise mechanism is still unknown. In the present study, we explored effects of simulated microgravity on nitric oxide (NO) level, inducible nitric oxide synthase (iNOS) expression and related regulative mechanism using electron spin resonance (ESR) spectroscopy, immunocytochemistry and in situ hybridization. We found a remarkable in-crease of NO level and up-regulation of iNOS and iNOS mRNA expression in rat cardiac myocytes under simulated microgravity. Staurosporine (a nonselective protein kinase inhibitor), calphostin C (a selective protein kinase C inhibitor), partially inhibited the effect of simulated microgravity. Thus regulative effect of simulated microgravity on iNOS expression is mediated at least partially via activation of protein kinase C. These results indicate that NO system in cardiac myocytes is sensi-tive to simulated microgravity and may play an important role in the depression of cardiac contrac-tility induced by simulated microgravity.
