Influences of traditional Chinese medicine intervention on the bone growth and metabolism of rats with simulated weightlessness

Objective:To prohe into the influences of Chinese herbal compound on the growth and metabolism of weight-bearing bones of tail-suspended rats.Methods:Twenty-four male St) rats were randomly divided into blank conlrol group leighti.tail-suspended conlrol group(eight) and Chinese medicine treatment group leighti according to their weights.No treatment was done for the blank conlrol group.Double distilled water lavage was performed daily for the tail-suspended control group.On the basis of the tail-suspended rat model,the rats were given Chinese herbal compound lavage every day in Chinese medicine treatment group.This compound includes mulberry,Poria cocas and barbary wolfberry.etc.The lest cycle was four weeks.The rats were killed after the experiment.The right femoral bone was taken out for the physical measurements, and the left femoral bone was for the three-point beading test.The influences of Chinese herbal compound on femoral hone growth and biomechanicsl properties of simulated weightlessness rats were observed.Results:(1) After simulated weightlessness(tail-suspension),compared with the blank control group,all the physiological indexes of rat femoral bone decreased in tailsuspended group and Chinese medicine treatment group(P【0.05).The strength and rigidity of rat femoral bone decreased in tail-suspended group(P【0.01).the maximum load and rigidity coefficient also decreased with the inereasing toughness coefficient in the control group(P【0.01). i2i After the countermeasure of Chinese herbal compound,each biomcchanical indexes showed the tendency of increasing in Chinese medicine treatment group,and theses indexes were close to those of the blank control group(P【0.05),which indicated that(he bone loss caused by simulated weightlessness was improved.Conclusions:Chinese herbal compound for tonifying kidney could effectively prevent the bone loss and have some enhancements on the bone hiomechanical properties.

Effects of Simulated Weightlessness on Tight Junction Protein Occludin and Zonula Occluden-1 Expression Levels in the Intestinal Mucosa of Rats

This study investigated the tight junction（TJ） protein expression of the intestinal mucosa in a rat tail-suspension model under simulated weightlessness.Twenty-four Wistar rats were randomly divided into three groups：CON group（n=8）,control; SUS-14 d group（n=8）,tail-suspension for 14 days; SUS-21 d group（n=8）,tail-suspension for 21 days.Occludin and Zonula Occluden-1（ZO-1） expression levels were determined by immunohistochemical analysis and mRNA fluorescent quantitative PCR.Plasma levels of diamine oxidase（DAO） and d-lactate were determined using enzymatic spectrophotometry.Immunohistochemical results for occludin and ZO-1 showed disruption of the TJs in the intestinal mucosa in SUS-14 d and SUS-21 d groups.The expression levels of occludin and ZO-1 in SUS-21 d group were lower than those in SUS-14 d group,and significantly lower than those in CON group（Occldin：0.86±0.02 vs 1.01±0.03 vs 1.63±0.03 and ZO-1：0.82±0.01 vs 1.00±0.02 vs 1.55±0.01,P〈0.01）.Moreover,the levels of plasma DAO and d-lactate in SUS-21 d group were higher than those in SUS-14 d group,and significantly higher than those in CON group（DAO：27.58±0.49 vs 20.74±0.49 vs 12.94±0.21 and d-lactate：37.86±0.74 vs 28.26±1.01 vs 17.76±0.91,P〈0.01）.There were significant negative correlations between occludin or ZO-1 expression levels and DAO（r2=0.9014,r2=0.9355,P〈0.01） or d-lactate levels（r2=0.8989,r2=0.9331,P〈0.01）.Occludin and Zo-1 were reduced in intestinal mucosa both in mRNA and protein levels in the rat tail-suspension model.The significant negative correlations between expression levels of TJs and plasma levels of DAO or d-lactate support the hypothesis that intestinal permeability is increased due to a decrease in TJ protein expression during tail-suspension from 14 days to 21 days.

EFFECT OF SIMULATED WEIGHTLESSNESS ON REPRODUCTION OF ADULT MALE RATS

Objective To study the effects of simulated weightlessness induced by tail-suspension on reproduction in adult male rats and its mechanisms. Methods Twenty Spraque-Dawley adult male rats were randomly divided into two groups: the experimental group and control group. Rats in the experimental group were tail-suspended for 14 days. After the treatment, the weight and morphology of testis, the quantity and quality of sperm, the level of serum testosterone and the apoptosis rate of testicular cells were observed. Results Compared with the control, the testicular weight, the quantity and quality of sperm, the level of serum testosterone significantly decreased (P<0.05) while the apoptosis rate of testicular cells significantly increased (P<0.05) in tail-suspended rats. In addition, hematoxylin and eosin (HE) staining showed that seminiferous tubules atrophied, spermatogenic cells decreased, seminiferous epithelial cells disintegrated and shed, and the lumina were azoospermic. Conclusion Simulated weightlessness induced by tail-suspension has a harmful effect on male reproduction of adult rats by increasing the apoptosis of testicular cells.

Changes of Stress-Strain Relationship of Rabbit Femoral Vein after Simulated Weightlessness

Objective:To observe the effect of simulated weightlessness on stress-strain relationship and the structural change of rabbit femoral vein. Methods:After sstiag up the Head-Doum Tilt (-20℃) (HDT) model to simulate weightlessness, 24 healthy male New-Zealand Rabbits were randomly divided into HDT-21d group, HDT 10d group and control group, with 8 in each. Femoral venous strips and rings were used to make uniaxial tensile test of the longitudinal and circumferential specimens of the vessels. At last we observed the microstructure of femoral vein wall in 3 groups. Results:With the increasing of load stress, both longitudinal and circumferential strains of vein samples from 3 groups increased significantly ( P<0. 01 ). With the decrease of unload stress, strains decrease obviously (P<0. 01). The unloaded longitudinal and the circumferential strain from 3 groups increased much than those of the loaded. Under the same stress (longitudinal 0-2. 0 g, circumferential 0. 5-1. 0 g), HDT-21d group and HDT-10d group increased obviously in the longitudinal or circumferential strain (load and unload) than control, and HDT-21d increased much than that of HDT-10d.The contents and structures of femoral vein walls of HI)T-rabbits changed siqnificantly. Some endothelium cells of femoral vein became short, columnar or cubic even fell off. Smooth muscle layers became thinner. Conclusion:The compliance of femoral venous increased significantly after weightlessness-simulation and increased much obviously after 21d-HDT than that of 10 d. The structure of femoral vein wall changed obviously. The changes may be one reason for the increase of femoral vein compliance.

THE MORPHOLOGICAL CHANGES IN MUSCLE SPINDLES AND ALTERATIONS IN CELL ACTIVITY OF THE RATS' RED NUCLEUS AFTER 2 WEEKS' SIMULATED WEIGHTLESSNESS

Objective To study the morphological changes of soleus muscle spindle and electrical activity of neurons in Red Nucleus(RN) of the rat after 2 weeks' simulated weightlessness, and to reveal the interaction between proprioceptive inputs of muscle spindles and reciprocal alterations in RN under simulated weightlessness. Methods Twenty female rats were exposed to weightlessness simulated by tail-suspension for 14 days (SW-14d). Body weight(200-220g) matched female rats were control group(Con). The morphological changes in isolated muscle spindle of soleus muscle, the discharges of red nucleus neurons were observed after 14d tail-suspensions by silver staining and extracellular recording respectively. Results Compared with control group ,the nerve ending of muscle spindle in SW-14d was distorted, degenerated and dissolved; the diameters of intrafusal fibers and capsule in equatorial region of soleus muscle spindles were diminished(P<0.05). The spontaneous cell activity and discharge of RN neurons (spikes/s) induced by afferent firing from muscle spindles after injection of succinylcholine were reduced after 2 weeks' simulated weightlessness respectively (18.44±5.96 vs. 10.19±6.88, 32.50±8.08 vs. 16.86±5.97, P<0.01). Conclusion The degeneration of muscle spindle induced by simulated weightlessness may be one of the causes that led to alterations in discharges of RN.

Fos expression in the medullary visceral zone following transient decrease of blood pressure in rats under simulated weightlessness

Objective: To observe Fos expression after transient decrease of blood pressure in catecholaminergic neurons of the medullary visceral zone(MVZ) in simulated weightlessness rats. Methods: Simulated weightlessness was abtained by tail suspension for 4 weeks, and transient decrease of blood pressure was induced by intravenous injection of sodium nitroprusside. Fos expression in catechlaminergic neurons of MVZ were visualized by an immunohistochemical double-labeling technique with anti-Fos and anti-tyrosine hydroxylase (TH) antibodies. Results: The decrease of blood pressure in the simulated weightlessness rats resulted in Fos expression in many neurons of the medulla oblongata, and they were primarily localized in the MVZ. In the MVZ, Fos-positive neurons were concentrated in the nucleus of the solitary tract (NTS) and ventrolateral region of the medulla (VLM). On the other hand, the numbers of Fos-positive neurons in MVZ were smaller than that of control rats (treated with tail suspension or intravenous injection of sodium nitroprusside only). Although some TH-positive neurons were found to be Fos-positive, the proportion of TH/Fos double-labeled neurons was much lower than that of the control rats; intensity of TH-like immunoreactivity was also reduced. Conclusion: The decrease of Fos-positive neurons and proportion of catechlaminergic neurons expressing Fos protein may result from decrease of parasympathetic activity in the simulated weightlessness rats.

Effects of electrostimulation and administration of succinylcholine on the expression of Fos protein in mesencephalic periaqueductal gray matter of rats after simulated weightlessness

BACKGROUND： Expression of Fos in neurons of periaqueductal gray （PAG） is used to reflect the excitability. However, changes of expression of Fos in neurons of PAG are caused by injured electrostimulation after simulated weightlessness, and the relationship between pretreatment and injection of succinylcholine has not been determined yet. OBJECTIVE ： To investigate the changes of expression of Fos in PAG induced by injured electrostimulation pretreatment and injection of succinylcholine at 2 weeks after simulated weightlessness.DESIGN： Observational and controlled animal study.SETTING： Department of Physiology, Medical School, Xi＇an Jiaotong University; Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education. MATERIALS： A total of 24 adult female SD rats, of clean grade and weighing 180-220 g, were selected in this study. METHODS： The experiment was completed in the Experimental Animal Center of Xi＇an Jiaotong University.① All rats were randomly divided into 2 groups according to body mass： simulated weightlessness group and control group with 12 in each group. And then, each group was also divided into 3 subgroups： electrostimulation group, succinylcholine-pretreatment group and succinylcholine-injection group with 4 in each subgroup. ②The model of weightlessness was simulated by tail-suspended female rats, which were described and modified by Cheng Jie. Rats in normal control group were given the same interventions as simulated weightlessness group except for tail-suspended. ③ Experimental method： The rats in electrostimulation group were given nociceptive stimulus by a pair of subcutaneous electrodes inserted into 1 and 5 claw of left hindlimb. The stimulus （current： 10 mA; duration： 1 ms; interval： 1 s） lasted for 30 minutes. The rats in succinylcholine-pretreatment group received stimulus after intravenous administration of succinylcholine, rats in succinylcholine-injection group were not given stimulus, just received succinylcholine. ④ All rats were perfused and fixed after 2 hours from the end of stimulation. The brains were removed, and serial frozen sections of midbrain were stained using immunocytochemical method, observed and taken photos under light-microscope. The number and morphological characters of Fos-immunoreactive （Fos-IR） neurons in ventrolateral part of PAG were investigated. MAIN OUTCOME MEASURES： The alterations in number and morphological characters of Fos-IR neurons in ventrolateral PAG of all rats.RESULTS： A total of 24 rats were involved in the final analysis. ① The morphological changes of Fos-IR neurons： The expressions of Fos in ventrolateral part of PAG were observed in both control and simulated weightlessness groups rats after being given nociceptive stimulus. As compared with control group, Fos-IR neurons in simulated weightlessness group were dyed lightly, cellular integrity was impaired, and cellular verge was unclear. ② The numbers of Fos-IR neurons： In control group, the numbers of Fos-IR neurons in ventrolateral part of PAG in simulated weightlessness group were obviously lower than succinylcholine-pretreatment group, but obviously higher than succinylcholine-injection group （46.94±3.38, 71.06±8.96 and 35.04±4.62, respectively, P 〈 0.05）. In 14-day simulated weightlessness group, the numbers of Fos-IR neurons in electrostimulation group were also obviously lower than succinylcholine-pretreatment group, and obviously higher than succinylcholine-injection group （27.77±3.27, 32.91±2.99 and 11.75±1.00, respectively, P 〈 0.05）. The numbers of Fos-IR neurons in all subgroups in control group were obviously higher than those subgroups in simulated weightlessness group. Compared with electrostimulation group, the percentage of expression of Fos in ventrolateral part of PAG responsed to nociceptive stimulus after administration of succinylcholine （SCH） was increased to 51.83% in control group and 18.51% in simulated weightlessness group.CONCLUSION ：① The expression of Fos in neurons in ventrolateral part of PAG were increased by the pretreatment of SCH before nociceptive stimulus.② Nociceptive stimulus could increase the expression of Fos in neurons in ventrolateral part of PAG. ③ The numbers of Fos-IR neurons in ventrolateral part of PAG were decreased obviously after 2-week simulated weightlessness.

Müller cells are activated in response to retinal outer nuclear layer degeneration in rats subjected to simulated weightlessness conditions

A microgravity environment has been shown to cause ocular damage and affect visual acuity,but the underlying mechanisms remain unclear.Therefore,we established an animal model of weightlessness via tail suspension to examine the pathological changes and molecular mechanisms of retinal damage under microgravity.After 4 weeks of tail suspension,there were no notable alterations in retinal function and morphology,while after 8 weeks of tail suspension,significant reductions in retinal function were observed,and the outer nuclear layer was thinner,with abundant apoptotic cells.To investigate the mechanism underlying the degenerative changes that occurred in the outer nuclear layer of the retina,proteomics was used to analyze differentially expressed proteins in rat retinas after 8 weeks of tail suspension.The results showed that the expression levels of fibroblast growth factor 2(also known as basic fibroblast growth factor)and glial fibrillary acidic protein,which are closely related to Müller cell activation,were significantly upregulated.In addition,Müller cell regeneration and Müller cell gliosis were observed after 4 and 8 weeks,respectively,of simulated weightlessness.These findings indicate that Müller cells play an important regulatory role in retinal outer nuclear layer degeneration during weightlessness.

长期模拟失重实验中医证候诊断量表的研究

目的制订适用于长期模拟失重实验受试者整体健康状态评价的中医证候诊断量表,并对其信度与效度进行初步评价。方法本研究基于对长期航天飞行不同阶段中的人体中医病机的认识,通过文献调研结合专家咨询的方法制订量表。采用重测信度和内部一致性系数来检验量表信度;进行为期90 d的头低位卧床实验,采用项目分析和因子分析法评价量表的效度,采用旋转成分矩阵分析各条目与维度间的相关性。结果长期模拟失重实验中医证候诊断量表包含8个维度、57个条目。信度分析结果:30名受试者前后两次量表评分总分相关系数为0.889,表明量表的稳定性很高;量表的克龙巴赫α系数为0.934,表明量表内部一致性非常好;分半信度校正后为0.858,表明量表的信度很高。效度分析结果:57个条目在高分组和低分组的差异均有统计学意义(P<0.01),各条目与量表总分的皮尔逊相关系数均>0.4(P<0.001);采用主成分因子分析法提取8个公因子,累积贡献率为55.293%;旋转成分矩阵分析结果经医理分析和专家反馈显示,与初始8个维度的重合度高达87.5%,表明量表的结构效度良好。结论量表具有良好的信度和效度,能够进行中医证候诊断,适用于长期模拟失重实验,可为受试者主观感受的评价提供客观量化新方法。

非接触式生理心理检测在长期模拟失重效应分析中的应用研究

目的在模拟失重生理效应场景下,构建基于面部视频的非接触式生理心理检测模型,探索长期模拟失重生理效应分析的非接触式心率和负性心境状态检测新方法。方法搭建可见光和热红外视频融合分析的非接触式生理心理数据采集系统,采集“地星二号”90 d头低位卧床实验中受试者生理心理相关数据,构建基于图卷积网络面部多区域特征融合的非接触式心率检测模型和考虑数据可靠性的非接触式负性心境状态检测模型,并以指夹式心率和POMS-SF量表为标签,验证模型的有效性。结果研究结果显示,非接触式心率检测模型的Bland-Altman图差值平均数为-1.26 bpm,且96.3%的误差值检测数据处于95%一致性区间内,模型检测的心率与指夹式心率有较高的一致性;非接触式负性心境状态检测模型对于紧张、压抑、愤怒、疲劳的检测准确率均超过0.85,且心率、AU06、眼部视线、头部姿态对心境状态检测的影响显著。结论非接触式生理心理检测方法不仅能够用于长期模拟失重的生理效应分析,还可为未来长期空间飞行的航天员在轨健康保障提供新途径。

中性浮力水下机械臂关键技术研究

水下机械臂可为航天员中性浮力训练提供转运和定点支持功能,提高训练过程的连贯性和效率。针对水下密封、中性浮力配平和防腐蚀3项水下机械臂关键技术,提出了采用多重冗余密封、浮力块与关节外壳赋形设计的技术方案,选用钛合金和双相不锈钢材料提升了机械臂的防腐蚀性能。研制的水下机械臂产品参与出舱活动训练已超过2年,最长在水下连续使用超过226天,工作状态良好,保证了空间站出舱活动水下试验的质量与有效性。

CKIP-1对模拟失重诱导的成骨细胞微丝变化的影响

【目的】探讨酪蛋白激酶结合蛋白1(CKIP-1)对模拟失重诱导的成骨细胞微丝变化的影响。【方法】选择小鼠成骨样细胞株(MC3T3-E1)进行研究,借助回转器模拟微重力环境,通过慢病毒感染构建CKIP-1过表达模型,将细胞分为a组(微重力组)、b组(空载慢病毒及微重力组)、c组(CKIP-1过表达慢病毒及微重力组)、d组(CKIP-1过表达慢病毒组)。使用FITC标记的鬼笔环肽对细胞进行荧光染色,在激光共聚焦显微镜下观察细胞微丝的变化,同时通过qRT-PCR技术测定CKIP-1 mRNA、ALP mRNA及RUNX2 mRNA的表达情况。【结果】每组细胞的微丝结构均呈现不同程度的解聚,而且张力纤维可见紊乱排列,并数量下降,以CKIP-1过表达慢病毒感染的成骨细胞模拟微重力组改变最为明显。c组、d组CKIP-1 mRNA表达水平高于a组、b组,差异有统计学意义(P<0.05)。c组成骨细胞RUNX2 mRNA、ALPL mRNA表达水平均低于a组、b组、d组,差异有统计学意义(P<0.05)。a组、b组、d组成骨细胞RUNX2 mRNA、ALPL mRNA表达水平比较,差异无统计学意义(P>0.05)。【结论】CKIP-1过表达可能会进一步加重微重力条件下成骨细胞骨架微丝的解聚,进而抑制成骨细胞增殖及分化。

模拟失重对大肠埃希菌生物学性状的影响研究

研究大肠埃希菌在模拟失重条件下连续传代培养14 d后生物学性状的变化。利用Gravite重力控制系统模拟失重条件连续传代培养大肠埃希菌14 d,对菌株的生长速率、形态学、生化代谢、生物膜、环境压力耐受性以及耐药性进行测定,评估模拟失重对大肠埃希菌生物学性状的影响。模拟失重可致大肠埃希菌生长速率增快、体积变小、生化代谢改变、环境压力耐受性及耐药性增加;而相应条件下的生物膜变化无统计学意义。模拟失重可引起大肠埃希菌相关的生物学性状发生变化。

尾悬吊模拟失重对小鼠肝脏及结肠DNA甲基化谱的影响

目的通过全基因组甲基化捕获测序技术,在尾悬吊模拟失重条件下,筛选小鼠肝脏和结肠DNA甲基化的差异性位点和区域,探讨失重对基因甲基化的具体影响。方法实验采用6只8周龄的雄性C57BL/6J品系小鼠,随机分为尾吊组和对照组,每组3只,进行为期42 d的尾悬吊模拟失重实验。实验结束后,从肝脏和结肠组织中提取DNA,并利用全基因组甲基化捕获测序技术进行分析。结果肝脏组织的DNA分析显示,共发现7517个差异甲基化位点和997个差异甲基化区域,涉及4892个基因。结肠组织的DNA分析显示,共筛选出70340个差异甲基化位点和12004个差异甲基化区域,影响12877个基因。基因本体论(GO)、京都基因和基因组数据库(KEGG)生物路径分析结果表明,这些差异甲基化基因主要参与了蛋白质结合、细胞粘附、细胞活化以及多种代谢途径。结论本研究通过高通量测序技术成功鉴定了模拟失重条件下小鼠肝脏和结肠的差异甲基化位点和区域,这些发现有助于深入理解在太空长期驻留对生物体基因甲基化的影响,为太空飞行相关疾病的筛选、早期诊断和治疗提供新的研究思路。

ASM/Cer通路介导模拟失重大鼠股动脉平滑肌细胞增殖与凋亡改变及表型转换

目的探究模拟失重(simulated weightlessness,SW)大鼠股动脉(femoral artery,FA)酸性鞘磷脂酶(acid sphingomyelinase,ASM)/神经酰胺(ceramide,Cer)通路改变及在FA平滑肌细胞增殖与凋亡改变及表型转换中的作用。方法采用后肢不荷重尾部悬吊(hindlimb unloaded tail suspended,HU)大鼠模拟微重力状态下血流动力学变化,通过蛋白免疫印迹分析、免疫组织化学染色等检测模拟失重大鼠ASM表达量、Cer含量以及血管平滑肌细胞增殖与凋亡及表型的改变。结果与对照(CON)组相比,HU大鼠FA血管平滑肌细胞中增殖细胞核抗原(proliferating cell nuclear antigen,PCNA)、半胱氨酸-天冬氨酸蛋白酶3(cysteinyl aspartate specific proteinase 3,Caspase3)、B淋巴细胞瘤-2(B-cell lymphoma-2,Bcl-2)和Bcl-2相关X蛋白(Bcl-2 associated X protein,Bax)的表达量,合成表型标记物(波形蛋白,Vimentin)/收缩表型标记物(α平滑肌肌动蛋白,α-smooth muscle actin,α-SMA)的比值以及ASM和Cer水平均显著升高(P<0.05)。此外,ASM抑制剂地昔帕明(desipramine,Dpm)孵育或盐酸多塞平(doxepin hydrochloride,DOX)灌胃后,HU大鼠FA中Bax的表达水平和Vimentin/α-SMA比值均显著降低(P<0.05)。Dpm孵育后,HU大鼠FA中Bcl-2表达呈上升趋势;DOX灌胃可显著增高HU组大鼠FA中Bcl-2的水平(P<0.05)。结论模拟失重可导致大鼠FA平滑肌细胞的增殖和凋亡水平均显著升高,并由收缩表型向合成表型转换,该重塑过程涉及ASM/Cer通路的过度激活。

Distribution of ^3H—nicotine in Rat Tissues Under the Influence of Simulated Microgravity

Rat tail suspension offers a useful model to reproduce physiologic responses to weightlessness.The present study was conducted in the head-down-tilt(HDT) rat model to assess changes in metabolism of body tissues employing 3H-nicotine. Twelve male rats were used in the study. Half of the rats were tail suspended at 30°for two weeks on a 12/12 light/dark cycle. During this period,body weight, food and fluid intakes were measured. At term, animals were anesthetized and injected IV withe a solution contaming 4 microuries of micotine. After 90 min the animals were sacrificed, exsanguinated and tissues (brain,blood,trachea,salivary gland,lung,heart,esophagus,spleen, kidneys and testes) were harvested. The distribution of 3H-nicotine per gram of each tissue was determinded and ealeulated as percent of total injected radioactivity. Final body weights of suspended ammals were significantly (P < 0.0 5) lower than those of eontrols(309±21 vs 350±11g). 3HNicotine waw retained in greatest amounts by the kindneys, followed inorder by salivary glands, spleen, and gastrointestinal tissues. compared to non-suspended control, the tissue retention of nicotine in suspended animals was decreased in the following tissues:esphyagus (25 %), aorta (25%). fundus (25%), trachea (22%), adrenals (18%), spleen (17 %), and pancreas (12 %). The decreased retention of mcotine in tissues from suspended animals may be indicative of the fluid shifts and changes in blood flow to those tissue beds. The lack of differnces in nicotine retention in liver and kidney between control and suspended groups may implicate a normal metabolic function of these organs even under simulated weightlessness.

Effects of simulated microgravity on antioxidant system in testis of adult rats

Objective： To study the effects of simulated microgravity induced by tail-suspension on histological structures and antioxidant system in testis of adult rats. Methods： Forty Spraque-Dawley adult male rats were randomly divided into four groups, two experimental groups and two synchronic control groups. Rats in the two experimental groups were tail-suspended for 14 d and 28 d respectively, then serum hormone, testicular morphology and biochemical changes were evaluated. Results： Compared with the synchronic controls, serum testosterone （T） levels and testicular superoxide dismutase （SOD） significantly decreased（P 〈 0.05）, while testicular malondialdehyde（MDA） significantly increased （P 〈 0.05） in tail-suspended rats. The changes were more prominent in the 28 d tail-suspended rats. In addition, hematoxylin and eosin （HE） staining showed that seminiferous tubules atrophied, spermatogenic cells decreased, and seminiferous epithelial cells disintegrated and shed, abnormal multinucleated giant cells appeared and the lumina were azoospermic in tail-suspended rats. ConcIusion： Simulated microgravity induced by tailsuspension has a harmful effect on male reproduction of adult rats by decreasing the ability of testicular antioxidant defense.

模拟失重后骨髓来源巨噬细胞转录组高通量测序及分析

目的探索模拟失重对小鼠骨髓来源巨噬细胞基因表达的影响。方法采用尾悬吊法构建模拟失重小鼠模型,对照组不做尾吊处理。模拟失重28 d后提取小鼠骨髓来源巨噬细胞并将其分别诱导为M0型和M1型巨噬细胞。随后,提取细胞总RNA进行转录组测序及分析,并通过实时定量RT-PCR验证重要基因的差异表达。结果转录组测序结果显示,模拟失重组与对照组之间的M0型巨噬细胞共有807个基因差异表达;模拟失重组与对照组之间的M1型巨噬细胞共有898个基因差异表达。GO分析表明,M0型巨噬细胞差异表达基因主要集中于免疫应答、趋化等生物学过程中;M1型巨噬细胞差异基因主要富集于炎症反应、细胞迁移的正调控和单核细胞趋化等生物学过程中。KEGG通路分析发现M0型巨噬细胞的差异基因主要涉及趋化因子、细胞因子-细胞因子受体相互作用等信号通路;M1型巨噬细胞的差异基因主要涉及造血细胞谱系、流体剪切应力等信号通路。进一步分析发现,尾吊组与对照组在M0或M1型巨噬细胞中的差异基因均在细胞因子-细胞因子受体相互作用信号通路中富集,其中尾吊组的M0与M1型巨噬细胞中调节单核细胞/巨噬细胞迁移和浸润的关键趋化因子Ccl2均显著高表达,并进一步通过RT-PCR实验得到验证。结论模拟失重可显著影响小鼠巨噬细胞中以Ccl2为代表的与炎症发生和加重密切相关的基因表达水平,这些改变的基因富集于多个生物学过程,可能对巨噬细胞的黏附、迁移等功能产生影响。

模拟失重实验动物模型的建立与评价

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。

人参皂苷对模拟失重巨噬细胞的保护作用研究

目的探究失重条件下炎症的作用机制及人参皂苷对巨噬细胞的炎症保护作用。方法首先通过GeneCards数据库检索与失重、炎症和免疫相关的基因,再通过基因/蛋白相互作用检索搜查工具(STRING)蛋白网络分析,寻找失重诱导炎症的核心靶点。通过非标记定量蛋白组学(LFQ)寻找人参皂苷处理人单核细胞白血病(THP-1)细胞的差异基因,通过基因本体(GO)、京都基因与基因组百科全书(KEGG)富集分析研究人参皂苷主要参与的生物过程和信号通路及人参皂苷针对失重性炎症的主要作用靶点。最后采用酶联免疫吸附试验(ELISA)法检测人参皂苷对脂多糖(LPS)诱导的THP-1细胞模拟失重期及失重恢复期白细胞介素(IL)-1β、IL-6、IL-8和肿瘤坏死因子α(TNF-α)的分泌影响。结果通过GeneCards数据库检索到炎症相关基因2933个,失重相关基因425个,免疫相关基因4564个。通过蛋白相互作用网络(PPI)确定了与失重诱导的炎症相关的靶点,如IL-1β、IL-6、TNF-α和白蛋白(ALB)。通过蛋白组学研究发现人参皂苷主要参与多种炎症相关信号通路及病原微生物感染通路,并显著改变CD40、IL-1β和腺苷二磷酸核糖聚合酶(PARP1)等蛋白表达。细胞模拟失重试验显示人参皂苷可以显著降低模拟失重期LPS诱导单核/巨噬细胞THP-1炎性因子IL-6、TNF-α的分泌(P<0.0001),同时还可降低失重恢复期IL-1β、IL-6、IL-8和TNF-α的分泌(P<0.0001)。结论失重可影响多种炎症相关信号通路,而人参皂苷可减少模拟失重巨噬细胞多种炎性因子的分泌起到缓解炎症的作用。本研究为进一步探究人参皂苷应用于防护失重条件下LPS诱导的炎症提供理论基础。