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失重条件对小鼠NK细胞体外生物活性的影响 总被引:2,自引:0,他引:2
建立在失重环境下NK细胞的培养体系,探讨失重培养条件对NK细胞活性的影响。取C57BL/6小鼠脾,分离NK细胞,在正常重力和失重状态下旋转细胞两种培养体系中培养NK细胞48 h。以Yac-1细胞为靶细胞,采用MTT法检测其杀伤活性;半定量PCR分析穿孔素、颗粒酶的转录水平。与正常重力培养对照相比,失重培养的NK细胞杀伤活性显著降低,其穿孔素和颗粒酶B的转录水平均显著低于正常重力培养组,穿孔素/GAPDH结果为失重培养组0.625±0.042;正常重力培养组1.054±0.036(P<0.01);得到颗粒酶B/GAPDH结果为失重培养组0.700±0.042;正常重力培养组1.068±0.058(P<0.01)。成功建立了NK细胞体外培养体系,在失重环境下NK细胞杀伤活性降低。 相似文献
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本文通过新生大鼠原代培养获取骨骼肌肌管,利用水平回转器模拟失重效应,通过F-actin/G-actin以及F-actin/pERK免疫细胞化学染色,观察研究了模拟失重对肌管形态、微丝及磷酸化ERK表达的影响。通过建立的航天飞行失重性肌萎缩的细胞学模型研究发现:回转后肌管变细,F-actin染色减弱伴有G-actin染色增强,同时pERK染色减弱。表明回转模拟失重条件下肌管发生萎缩、微丝解聚并伴随信号转导活性分子磷酸化ERK表达下降。提示肌管细化是失重性肌萎缩结构和功能变化的结构基础 相似文献
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随着航天技术不断发展,航天员太空飞行的时长不断增加。研究发现,航天失重环境可能会使航天员的生理和心理发生一定变化,对航天员的身体健康产生一些影响。为探究这些影响的机制并找出合理的对抗措施,使用实验动物建立模拟失重模型进行深入的研究至关重要,选择与人体组织器官、生理机能和习性相似的实验动物建立模拟失重模型,能更好地帮助相关研究。失重模型应参照能否模拟出由于失重引起心血管骨骼、肌肉等主要系统的变化,来评估模拟失重模型是否成功建立。本文对现有的地面模拟失重动物模型建立和相关研究情况进行了概述,以期为开展相关研究工作提供参考借鉴。 相似文献
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模拟失重对大鼠腹主动脉L-Arg-NO-cGMP通路的影响 总被引:1,自引:0,他引:1
目的:观察尾部悬吊模拟失重对大鼠腹主动脉舒张反应性与一氧化氮合酶表达的影响。方法:体重300~330 g的20只雄性SD大鼠按体重配对随机分为对照组与模拟失重组,模拟失重大鼠采用尾部悬吊方法模拟失重。4周后,利用离体动脉血管环舒张实验与Western blot蛋白免疫印迹方法观察了腹主动脉舒张反应性和腹主动脉一氧化氮合酶eNOS(endothelial NOS)和iNOS(inducible NOS)的表达。结果:悬吊大鼠腹主动脉环对左旋精氨酸(L-Arg)与乙酰胆碱(Ach)的舒张反应显著低于对照,而对硝普钠(SNP)与环磷酸鸟苷(cGMP)的舒张反应在两组间无显著不同。其敏感性在两组间均无显著差别。腹主动脉的eNOS与iNOS表达在模拟失重组与对照组间亦未发现显著差别。结论:本工作提示尾部悬吊模拟失重下大鼠腹主动脉舒张反应的减弱可能是动脉血管内皮功能改变的结果,尤其是NOS活性的变化可能更为重要。 相似文献
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【背景】我国未来几年深空探索任务将呈"井喷式"发展,微生物对于航天活动的影响越来越引起关注,而国内外少有表型异质性亚群的研究。【目的】从表型异质性的角度探讨低剪切力模拟失重环境(Low-shearmodeledmicrogravity,LSMMG)和低剪切力正常重力环境(Low-shearnormalgravity,LSNG)对大肠杆菌K12造成的影响。【方法】利用旋转细胞培养系统模拟失重环境对大肠杆菌K12进行连续传代培养,从单克隆形态、颜色以及菌体形态等方面挑选出表型异质性的亚群菌株,对不同菌株进行增殖速率、抗生素耐药性、生物被膜形成、环境压力抵抗力以及细胞毒性的测定,以此评估低剪切力和模拟失重环境对大肠杆菌K12的影响。【结果】利用旋转细胞培养系统连续传代培养,总共分离出4株形态不同的表型异质性亚群菌株,其中2株来自模拟失重组(M1,Ma),另外2株来自正常重力对照组(N1,Na);4株亚群与原始菌株(P)相比,在增殖速率、生物被膜形成、环境压力抵抗力和细胞毒性方面均有增强或减弱的明显变化,对于抗生素的耐药性无明显变化。【结论】低剪切力模拟失重环境以及存在低剪切力的正常重力环境均能引起大肠杆菌表型异质性变化,与原始菌株相比,表型异质性亚群菌株在分化上并没有统一的方向,但仍需警惕那些可能对人类造成危害的变化表型。 相似文献
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我国载人航天已经进入中长期飞行阶段,失重是航天员在长期的航天飞行和空间驻留时面临的一种极端的航天特因环境,除了会对航天员的身体健康产生严重的影响,还极易诱发神经精神功能紊乱,包括反应、判断、决策等认知功能减退。由于航天飞行的特殊性,在地面采用实验模拟航天失重,探究失重对机体的影响,并找到防护措施是至关重要的。因此,本文从失重效应模拟实验方法出发,综述模拟失重对机体功能的影响。 相似文献
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骨骼肌收缩实验作为大学生理学课程中一个传统的教学实验,在国内各高校的生理学教学中多有开设。本教研室一直致力于模拟失重致骨骼肌废用性萎缩方面的研究,结合科研课题对该教学实验进行了改进:以模拟失重小鼠作为实验动物,代替原用的蛙或蟾蜍;在保留原有实验内容的基础上,加入正常小鼠与模拟失重小鼠骨骼肌收缩能力的测定等新内容。通过在教学中的实际应用,发现改进后的实验不但能够完成传统的实验内容,还可通过模拟失重小鼠与正常小鼠收缩能力的测定和对比,体现模拟失重对骨骼肌收缩功能的影响,进而加深学生对骨骼肌收缩过程的理解,提高学生对失重影响人体生理功能的认识。改进后的骨骼肌收缩实验丰富了传统实验的内容,拓宽了该实验的理论和应用,有助于激发学生对生理学的学习兴趣,明显提升教学效果。 相似文献
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Sarkar P Sarkar S Ramesh V Kim H Barnes S Kulkarni A Hall JC Wilson BL Thomas RL Pellis NR Ramesh GT 《Neurochemical research》2008,33(11):2335-2341
Exposure to altered microgravity during space travel induces changes in the brain and these are reflected in many of the physical
behavior seen in the astronauts. The vulnerability of the brain to microgravity stress has been reviewed and reported. Identifying
microgravity-induced changes in the brain proteome may aid in understanding the impact of the microgravity environment on
brain function. In our previous study we have reported changes in specific proteins under simulated microgravity in the hippocampus
using proteomics approach. In the present study the profiling of the hypothalamus region in the brain was studied as a step
towards exploring the effect of microgravity in this region of the brain. Hypothalamus is the critical region in the brain
that strictly controls the pituitary gland that in turn is responsible for the secretion of important hormones. Here we report
a 2-dimensional gel electrophoretic analysis of the mouse hypothalamus in response to simulated microgravity. Lowered glutathione
and differences in abundance expression of seven proteins were detected in the hypothalamus of mice exposed to microgravity.
These changes included decreased superoxide dismutase-2 (SOD-2) and increased malate dehydrogenase and peroxiredoxin-6, reflecting
reduction of the antioxidant system in the hypothalamus. Taken together the results reported here indicate that oxidative
imbalance occurred in the hypothalamus in response to simulated microgravity. 相似文献
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失重条件下人和动物生理状态会发生一系列的变化,其中骨骼肌萎缩和力量下降较为显著,目前其发生的机制仍不明确且缺少特效的干预措施。本文从肌肉湿重及肌纤维横截面积的变化、肌纤维类型的变化、肌纤维超微结构的变化、肌梭的适应性变化四个方面进行简要阐述,探讨肌肉萎缩的可能发生机制。 相似文献
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Majumder S Siamwala JH Srinivasan S Sinha S Sridhara SR Soundararajan G Seerapu HR Chatterjee S 《Journal of cellular biochemistry》2011,112(7):1898-1908
Faster growth and differentiation of liver stem cells to hepatocyte is one of the key factors during liver regeneration. In recent years, simulated microgravity, a physical force has shown to differentially regulate the differentiation and proliferation of stem cells. In the present work, we studied the effect of simulated microgravity on differentiation and proliferation of liver stem cells. The cells were subjected to microgravity, which was simulated using indigenously fabricated 3D clinostat. Proliferation, apoptosis, immunofluorescence assays and Western blot analysis were carried out to study the effects of simulated microgravity on liver stem cells. Microgravity treatment for 2 h enhanced proliferation of stem cells by twofold without inducing apoptosis and compromising cell viability. Analysis of hepatocyte nuclear factor 4‐α (HNF4‐α) expression after 2 h of microgravity treatment revealed that microgravity alone can induce the differentiation of stem cells within 2–3 days. Probing bone morphogenic protein 4 (BMP4) and Notch1 in microgravity treated stem cells elaborated downregulation of Notch1 and upregulation of BMP4 after 2 days of incubation. Further, blocking BMP4 using dorsomorphin and chordin conditioned media from chordin plasmid transfected cells attenuated microgravity mediated differentiation of liver stem cells. In conclusion, microgravity interplays with BMP4/Notch1 signaling in stem cells thus inducing differentiation of stem cells to hepatocytes. Present findings can be implicated in clinical studies where microgravity activated stem cells can regenerate the liver efficiently after liver injury. J. Cell. Biochem. 112: 1898–1908, 2011. © 2011 Wiley‐Liss, Inc. 相似文献
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Angiogenesis is a physiological process involving the growth of blood vessel in response to specific stimuli. The present study shows that limited microgravity treatments induce angiogenesis by activating macrovascular endothelial cells. Inhibition of nitric oxide production using pharmacological inhibitors and inducible nitric oxide synthase (iNOS) small interfering ribo nucleic acid (siRNA) abrogated microgravity induced nitric oxide production in macrovascular cells. The study further delineates that iNOS acts as a molecular switch for the heterogeneous effects of microgravity on macrovascular, endocardial and microvascular endothelial cells. Further dissection of nitric oxide downstream signaling confirms that simulated microgravity induces angiogenesis via the cyclic guanosine monophosphate (cGMP)-PKG dependent pathway. 相似文献
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Spisni E Toni M Strillacci A Galleri G Santi S Griffoni C Tomasi V 《Cell biochemistry and biophysics》2006,46(2):155-164
Studies in modeled microgravity or during orbital space flights have clearly demonstrated that endothelial cell physiology
is strongly affected by the reduction of gravity. Nevertheless, the molecular mechanisms by which endothelial cells may sense
gravity force remain unclear. We previously hypothesized that endothelial cell caveolae could be a mechanosensing system involved
in hypergravity adaptation of human endothelial cells. In this study, we analyzed the effect on the physiology of human umbilical
vein endothelial cell monolayers of short exposure to modeled microgravity (24–48h) obtained by clinorotation. For this purpose,
we evaluated the levels of compounds, such as nitric oxide and prostacyclin, involved in vascular tone regulation and synthesized
starting from caveolae-related enzymes. Furthermore, we examined posttranslational modifications of Caveolin (Cav)-1 induced
by simulated microgravity. The results we collected clearly indicated that short microgravity exposure strongly affected endothelial
nitrix oxide synthase activity associated with Cav-1 (Tyr 14) phosphorylation, without modifying the angiogenic response of
human umbilical vein endothelial cells. We propose here that one of the early molecular mechanisms responsible for gravity
sensing of endothelium involves endothelial cell caveolae and Cav-1 phosphorylation. 相似文献