G-B-R复配物对模拟微重力效应诱导骨丢失的防护作用

目的 从天然产物中寻找到对微重力效应诱导骨丢失具有防护作用的复配物。方法 通过24种天然产物对骨髓干细胞和成骨细胞的增殖活性,筛选出具有较强效果的天然产物并对其进行复配;随后通过复配物对模拟微重力效应下昆明小鼠骨质丢失的影响来评价其骨丢失防护作用。结果银杏叶和荞麦花粉的复配物显示出最强的骨髓干细胞增殖活性;熟地黄显示出最强的成骨细胞增殖活性;在模拟微重力环境下不同剂量的银杏叶、荞麦花粉与熟地黄的复配物均显示出不同程度的骨丢失防护作用;高剂量组可以显著提高模型组小鼠血清中碱性磷酸酶的活性及股骨中的有机物含量。结论 通过对天然产物促骨髓干细胞和成骨细胞增殖活性进行筛选和复配,发现所获得的G-B-R复配物对微重力效应诱导的骨丢失具有良好的防护作用。     

雷奈酸锶在模拟微重力环境对成骨细胞分化功能的影响

目的 观察雷奈酸锶这种新型的抗骨质疏松药,在模拟微重力环境对成骨细胞分化功能的影响.方法 利用碱性磷酸酶活性测定了解小鼠成骨样细胞MC3T3-E1的分化情况,利用旋转细胞培养系统模拟微重力环境.结果 模拟微重力环境可以抑制MC3T3-E1细胞分化功能,雷奈酸锶可以保护模拟微重力环境MC3T3-E1细胞的分化功能.结论 在模拟微重力环境雷奈酸锶对成骨细胞分化功能具有保护作用,这为雷奈酸锶治疗微重力环境骨丢失提供了理论和实验依据.     

瘦素对骨代谢影响研究进展

瘦素及其受体在中枢和外周多个部位均有表达,具有多种生物学功能,对于骨代谢有着重要的影响作用.近来研究发现瘦素可促进人骨髓间质细胞向成骨细胞分化,抑制其向脂肪细胞分化;血清瘦素水平还与成骨细胞活性及骨骼发育相关.瘦素在外周作用于多种骨细胞促进成骨,在中枢系统则抑制骨形成.瘦素在妇女绝经后骨质疏松的发生中发挥一定作用.该文主要归纳介绍瘦素调节骨代谢基本作用及调控骨骼生长作用的一些较重要的研究发现,并对其机制作初步探讨.     

模拟微重力培养在骨和软骨组织工程中的应用

骨和软骨组织工程主要致力于骨和软骨的形成和再生,通过建立细胞与生物材料的三维复合物,构建具有生物活性的组织,进而对受损的骨和软骨组织进行形态结构和功能的重建以求达到永久性替代.目前模拟微重力条件下骨和软骨组织工程的研究表明,微重力培养环境有利于细胞体外增殖和分化,并维持细胞的表型;有利于细胞和材料的三维立体复合;有利于构建的组织更接近于活体.因此微重力细胞培养为骨和软骨组织工程的研究开辟了新的道路.     

肠道菌群对代谢术后骨代谢的影响

肠道菌群的改变对宿主起着多方面的影响。代谢手术对肠道结构及生理功能的改变影响了寄居于肠道内的菌群。而这些菌群的变化参与了术后体重下降﹑糖代谢及脂代谢的改变。同时已有很多研究证实肠道菌群的变化可以通过影响宿主的代谢系统﹑神经系统﹑免疫调节系统对骨代谢造成不容忽视的影响。益生菌作为一种对宿主有益的活性微生物，其骨保护作用也越来越得到重视。本文从减重术后肠道菌群的改变﹑肠道菌群对骨代谢的影响及益生菌与骨代谢等方面进行综述，总结近年来的研究进展及热点，搭建肠道菌群与代谢术后骨代谢相关多学科之间的桥梁，为代谢术后的菌群治疗、靶点研究奠定基础。     

痩素对骨代谢的影响

瘦素(Leptin)是一种主要由白色脂肪组织产生的16kDa蛋白质(胎盘、胃和骨骼肌也有少量产生)，由三个外显子的ob基因编码。Leptin在血浆中的浓度与机体脂肪储备量正相关，通过下丘脑神经元来调节摄食行为、能量代谢和生殖内分泌功能。近来的研究发现瘦素不仅与物质能量代谢有关，而且对     

血小板衍生生长因子对骨代谢的影响

骨折、骨不连、骨缺损、骨质疏松等一直是困扰骨科界的难题。骨折愈合期漫长 ,易产生各种并发症 ;而骨不连、骨缺损目前临床上尚无有效治疗方法。除了组织工程 ,近年研究热点主要集中在骨组织的代谢调节 ,包括各种生长因子的调节以及细胞间信号传导等。作为一种调节骨组织代谢的重要因子 ,血小板衍生生长因子 (platelet derivedgrowthfactor,PDGF)越来越受到国内外学者的重视。笔者就PDGF对骨代谢的影响加以综述1　生物学特性PDGF是一种耐热、耐酸、易被胰蛋白酶水解的阳离子多肽 ,主要由成熟的血小板分泌 ,与血小板因子 4、纤维蛋白…     

代谢肥胖对雄性大鼠骨代谢影响

[目的]探讨代谢肥胖对雄性SD大鼠青年期（17周龄）和成年期（27周龄）骨代谢的影响。[方法] 5周龄雄性SD大鼠40只，按随机数字表法随机分成普食组（normal diet, ND组）、高脂组（High-fat diet, HFD组），分别给予ND和HFD饲养至17周和27周。检测血清骨代谢标志物，行微型CT检查和三点弯曲力学测试。[结果]两组大鼠17周龄时血Ca、P、PINP、CTX的差异均无统计学意义（P>0.05）。27周龄时HFD组大鼠PINP显著小于ND组（P<0.05），而CTX显著大于ND组（P<0.05）。随周龄增加，大鼠体重及肌肉量显著增加（P<0.05）。与ND组相比，17周龄HFD组大鼠的Tb.vBMD、Tb.BV/TV、Tb.N均显著减少（PP<0.05），而Tb. Sp显著增加（P<0.05）。27周龄HFD组大鼠的Tb. vBMD、Tb. BV/TV、Tb. Th、Tb. N均显著减少（P<0.05）,Tb. Sp和SMI显著增加（P<0.05）。与17周相比，27周ND组最大负荷、最大断裂负荷、能量吸收、韧...     

降钙素基因多肽对骨代谢的影响

根据骨质疏松的发病机制不同,可分为原发性骨质疏松和继发性骨质疏松,原发性骨质疏松又可分为绝经性骨质疏松和老年性骨质疏松。骨质疏松是由多种发病因素共同作用的结果,在各型骨质疏松中,降钙素均发挥重要的调节作用。近年研究发现某些神经、血管活性肽,如降钙素基因多肽(Calcitonin gene-related peptide,CGRP）,在结构和功能上与降钙素具有一定的相似性。本文将降钙素基因多肽对骨代谢影响的相关研究进展作以下综述。     

微重力引起的骨质丢失研究进展

人类对太空的探索日益频繁,然而太空微重力会引起航天员骨质丢失,对航天员的健康造成损害。因此,有研究者通过航天实验及模拟微重力实验研究微重力下骨质丢失的发生机制及解决措施。微重力会引起成骨细胞和破骨细胞代谢活动改变,并引起机体对钙离子新陈代谢的改变。航天微重力导致的骨质丢失是微重力和太空射线共同作用的结果。本文将对微重力所致骨质丢失的发生机制和治疗对策加以概述。     

The effect of simulated microgravity by three-dimensional clinostat on bone tissue engineering

Evidence suggests that mechanical stress, including gravity, is associated with osteoblast differentiation and function. To examine effects of microgravity on bone tissue engineering, we used a three-dimensional (3D) clinostat manufactured by Mitsubishi Heavy Industries (Kobe, Japan). A 3D clinostat is a device that generates multidirectional G force. By controlled rotation on two axes, it cancels the cumulative gravity vector at the center of the device. We cultured rat marrow mesenchymal cells (MMCs) in the pores of interconnected porous calcium hydroxyapatite (IP-CHA) for 2 weeks in the presence of dexamethasone using the 3D clinostat (clinostat group). MMCs cultured using the 3D clinostat exhibited a 40% decrease in alkaline phosphatase activity (a marker of osteoblastic differentiation), compared with control static cultures (control group). SEM analysis revealed that although there was no difference between the two groups in number or distribution of cells in the pores, the clinostat group exhibited less extensive extracellular matrix formation than the control group. Cultured IP-CHA/MMC composites were then implanted into subcutaneous sites of syngeneic rats and harvested 8 weeks after implantation. All implants showed bone formation inside the pores, as indicated by decalcified histological sections and microfocus computed tomography. However, the volume of newly formed bone was significantly lower for the clinostat group than for the control group, especially in the superficial pores close to the implant surface. These results indicate that new bone formation in culture was inhibited by use of the 3D clinostat, and that this inhibition was mainly due to suppression of osteoblastic differentiation of MMCs.     

蛇床子素对模拟微重力引起的骨质流失的防治作用

目的研究蛇床子素对模拟微重力导致大鼠骨质流失的防治作用。方法将Wistar大鼠随机分为3组:对照组(Ctrl)、尾吊组(HLS)、尾吊给药组(OST)。4周后取后肢骨用双能骨密度仪及万能试验机分别测量各组股骨骨密度及生物力学,并通过micro CT分析骨小梁参数;用Van Gieson(VG)染色观察胫骨形态变化。通过qRT-PCR检测胫骨骨保护素(OPG)和核因子-κB受体激活剂配体(RANKL)mRNA表达水平。用ELISA试剂盒检测血清中骨特异性碱性磷酸酶(BALP)、骨钙素(OCN)和抗酒石酸酸性磷酸酶-5b(TRACP-5b)的含量变化。结果与对照组相比,尾吊组大鼠股骨骨密度及生物力学参数显著降低(P0.05),与尾吊组相比,尾吊给药组骨密度及生物力学显著上升(P0.05);尾吊组骨小梁体积分数(BV/TV)、厚度(Tb.Th)显著降低(P0.01),间距(Tb.Sp)显著升高(P0.01),尾吊给药后BV/TV、Tb.Th及Tb.Sp显著降低(P0.01);VG染色观察尾吊组胫骨骨小梁间隙变大,数量减少,而尾吊给药组骨小梁骨髓腔减少,数量增多;尾吊组血清BALP和OCN浓度显著降低(P0.05),TRACP-5b浓度显著升高(P0.05),当给予蛇床子素后,BALP浓度显著升高(P0.05),而TRACP-5b浓度显著降低(P0.05);尾吊组胫骨OPG/RANKL比值显著降低(P0.05),尾吊给药后,OPG/RANKL比值显著升高(P0.05)。结论蛇床子素可通过促进骨形成和抑制骨吸收两方面有效防治模拟微重力导致的骨质流失。     

The effects of simulated microgravity on intervertebral disc degeneration

Background contextAstronauts experience back pain, particularly low back pain, during and after spaceflight. Recent studies have described histologic and biochemical changes in rat intervertebral discs after space travel, but there is still no in vitro model to investigate the effects of microgravity on disc metabolism.PurposeTo study the effects of microgravity on disc degeneration and establish an in vitro simulated microgravity study model.Study designDiscs were cultured in static and rotating conditions in bioreactor, and the characteristics of disc degeneration were evaluated.MethodsThe mice discs were cultured in a rotating wall vessel bioreactor where the microgravity condition was simulated. Intervertebral discs were cultured in static and microgravity condition. Histology, biochemistry, and immunohistochemical assays were performed to evaluate the characteristics of the discs in microgravity condition.ResultsIntervertebral discs cultured in rotating bioreactors were found to develop changes of disc degeneration manifested by reduced red Safranin-O staining within the annulus fibrosus, downregulated glycosaminoglycan (GAG) content and GAG/hydroxyproline ratio, increased matrix metalloproteinase 3 expression, and upregulated apoptosis.ConclusionsWe conclude that simulated microgravity induces the molecular changes of disc degeneration. The rotating bioreactor model will provide a foundation to investigate the effects of microgravity on disc metabolism.     

模拟微重力培养肝细胞的形态特点

目的　模拟微重力方法培养大鼠原代肝细胞 ,初步分析其形态学特点及其意义。方法　改良Seglen原位胶原酶灌注法获得大鼠肝脏单细胞悬液 ,2 .2× 10 5个 /ml加微载体Cytodex 3(4 g/L)接种 ,采用旋转细胞培养系统 (RCCS)进行模拟微重力培养。第 0、6、2 4、72、12 0、168小时取样 ,相差、体视显微镜观察活细胞形态 ,第 2 4小时标本苏木素 伊红 (HE)染色观察组织学形态 ,电镜观察超微结构。结果　模拟微重力培养中肝细胞 2 4h内贴附微载体并出现三维结构 ,2 4～ 72h发展为独特的肝细胞 微载体聚球体。电镜下可见细胞膜的 3种不同形态 ,其分布与功能相一致。结论　模拟微重力培养方法能使肝细胞形成分化的三维类组织结构 ,在组织工程领域存在良好的应用前景     

雷奈酸锶在模拟微重力环境对成骨细胞增殖功能的影响

目的 观察新型的抗骨质疏松药雷奈酸锶在模拟微重力环境下对成骨细胞增殖功能的影响.方法 利用沿水平轴连续回转(30 r/min)细胞培养系统模拟微重力环境,使用MTT比色法或台盼兰染色、细胞计数法观察小鼠成骨样细胞MC3T3-E1的增殖情况.结果 模拟微重力环境可以降低MC3T3-E1增殖功能,雷奈酸锶在模拟微重力环境可以增强MC3T3-E1增殖功能.结论 在模拟微重力环境下雷奈酸锶对成骨细胞增殖功能具有保护作用,为雷奈酸锶治疗微重力环境骨量丢失提供了理论和实验证据.     

模拟微重力培养大鼠胰岛的形态学观察

目的应用电子显微镜观察模拟微重力培养对大鼠胰岛形态的影响。方法将新鲜分离和消化的大鼠胰岛分别进行普通培养和模拟微重力条件培养 ,应用扫描电镜和透射电镜观察各组大鼠胰岛的大体结构及超微结构的变化 ,并与新鲜分离的胰岛对照。结果培养 7d时透射电镜下观察微重力组的胰岛形态类似新鲜组的胰岛 ,胞浆内有发育良好的分泌颗粒和丰富的线粒体 ;扫描电镜显示只有微重力组胰岛与胰岛之间形成了许多小洞。结论模拟微重力培养时 ,胰岛的形态保持良好。     

Effect of simulated microgravity on testosterone and sperm motility in mice

We examined changes in the serum testosterone level and in sperm in the testis and epididymis by using tail-suspended mice, which are a simulation model of the body fluid shift in space, to evaluate the possibility of spermatogenesis failure in space environment. We also studied pathological disorders of the testis in the tail-suspended mice. Tail suspension was imposed with a tail harness to a degree at which the hindlegs of mice did not touch the floor of the housing unit. In control mice, the tail was similarly fixed with a tail harness to impose the same stress, except that a hindleg remained on the floor. Body weight was not significantly different between the 2 groups during 7 days, and testicular weight was significantly different. The testosterone level was significantly lower in the tail-suspended group (0.71 +/- 1.24 ng/mL) than in the control group (2.38 +/- 3.50 ng/mL; P <.05). Microscopy with hematoxylin and eosin (HE) and periodic acid-Schiff (PAS) staining showed a small proportion of seminiferous tubules with impairment of spermatogenic function in the tail-suspended group, and multinucleated giant cells were occasionally noted. Terminal deoxynucleotidyl tranferase-mediated nick end-labeling staining revealed positive cells even in animals in which impairment was considered to be mild based on HE and PAS staining. Many cells showed intense p53 immunostaining compared to the control group, with more intense staining of the nucleus in the tail-suspended group. The proportion of motile sperm was slightly but not significantly reduced in the tail-suspended group. However, the mean movement velocity of the motile spermatozoa was significantly decreased.     

WISE-2005: bed-rest induced changes in bone mineral density in women during 60 days simulated microgravity

To better understand the effects of prolonged bed-rest in women, 24 healthy women aged 25 to 40 years participated in 60-days of strict 6° head-down tilt bed-rest (WISE-2005). Subjects were assigned to either a control group (CON, n = 8) which performed no countermeasure, an exercise group (EXE, n = 8) undertaking a combination of resistive and endurance training or a nutrition group (NUT, n = 8), which received a high protein diet. Using peripheral quantitative computed tomography (pQCT) and dual X-ray absorptiometry (DXA), bone mineral density (BMD) changes at various sites, body-composition and lower-leg and forearm muscle cross-sectional area were measured up to 1-year after bed-rest. Bone loss was greatest at the distal tibia and proximal femur, though losses in trabecular density at the distal radius were also seen. Some of these bone losses remained statistically significant one-year after bed-rest. There was no statistically significant impediment of bone loss by either countermeasure in comparison to the control-group. The exercise countermeasure did, however, reduce muscle cross-sectional area and lean mass loss in the lower-limb and also resulted in a greater loss of fat mass whereas the nutrition countermeasure had no impact on these parameters. The findings suggest that regional differences in bone loss occur in women during prolonged bed-rest with incomplete recovery of this loss one-year after bed-rest. The countermeasures as implemented were not optimal in preventing bone loss during bed-rest and further development is required.