诱导多能干细胞重编程方法的优化及其在航天医学中的应用展望

近年来,通过外源导入特定的转录因子,将体细胞重编程为类似胚胎干细胞（ESCs）潜能的诱导多能干细胞（iPSCs）掀起了干细胞研究的又一热潮,然而重编程效率低和安全性等问题严重阻碍着其临床应用.太空环境对成体干细胞分化潜能的影响是航天员生理变化的因素之一,具有类似ESCs全能性的iPSCs将为发育生理学及再生医学研究带来全新的视角.综述了iPSCs的研究进展,重点阐述提高安全性和重编程效率的方法和应用研究现状,并探讨了其在航天医学领域中的应用前景.     

大鼠骨髓间充质干细胞体外向血管平滑肌样细胞诱导分化过程中Periostin的表达及其作用

目的探讨血小板源性生长因子(Platelet derived growth factor,PDGF)-BB诱导骨髓间充质干细胞(Bone marrow-derived mesenchymal stem cells,BMSCs)向血管平滑肌样细胞(Vascular smooth muscle-like cells,VSMLCs)分化过程中Periostin的表达及其在促VSMLCs分化中的作用。方法采用全骨髓贴壁培养法分离和培养大鼠BMSCs,取第2代BMSCs分为2组:诱导Ⅰ组(用50 ng/ml PDGF-BB单独向VSMLCs诱导)和诱导Ⅱ组(加入地塞米松1μmol/L、胰岛素1μmol/L、吲哚美辛1μmol/L、3-异丁基-1甲基黄嘌呤0.5 mmol/L,向脂肪样细胞诱导),以大鼠胸大动脉平滑肌细胞作为阳性对照。分别于诱导后7 d和14 d,采用RT-PCR检测细胞中平滑肌肌动蛋白(SMα-actin)、平滑肌肌球蛋白重链(SM MHC)、平滑肌肌钙结合蛋白(SM Calponin)和Periostin mRNA的转录水平,Western blot检测Periostin蛋白的表达水平。结果诱导Ⅰ组细胞的SMα-actin、SM MHC、SMCalponin和Periostin基因mRNA及Periostin蛋白的表达水平14 d比7 d显著增强,且差异有统计学意义(P<0.05);14 d与阳性细胞相比,差异无统计学意义(P>0.05);未诱导组及诱导Ⅱ组在14 d均无表达。结论 PDGF-BB(50 ng/ml)能够单独诱导BMSCs向VSMCs分化,Periostin在此过程中起重要作用。     

二磷酸氯喹对THP-1细胞增殖及凋亡的影响

目的探讨不同浓度二磷酸氯喹对急性单核细胞性白血病细胞THP-1增殖及凋亡的影响。方法分别用10、20、40、80、100μmol/L氯喹处理THP-1细胞,分别于处理12、24、48和72 h收集细胞,MTS法检测细胞增殖情况,同时采用Hoechst33342荧光染色法及流式细胞仪检测二磷酸氯喹对THP-1细胞凋亡的影响。结果处理细胞12、24 h时,10、20、40、80、100μmol/L二磷酸氯喹对细胞增殖无明显影响,各组间差异无统计学意义(P0.05);处理细胞48、72 h时,各浓度二磷酸氯喹对细胞增殖均有抑制作用,细胞活力均明显下降,各组间差异有统计学意义(P0.01),并具有剂量依赖性。不同浓度二磷酸氯喹对THP-1细胞凋亡均具有诱导作用,且随着浓度的增加,细胞凋亡愈加明显。结论二磷酸氯喹在体外可抑制THP-1细胞的增殖,并诱导细胞凋亡,其作用具有剂量依赖性。     

4种来源的间充质干细胞的生物学特性比较

目的比较骨髓、骨骼肌、肋软骨膜及软骨来源的间充质干细胞(mesenchymal stem cells,MSCs)的生长、免疫表型及体外诱导分化能力的差异。方法分别获取新西兰大白兔的骨髓、骨骼肌、肋软骨膜细胞及软骨细胞,体外培养观察其生长形态、表型特征及其诱导成骨、成脂的分化能力。结果 4种来源的MSCs均从第2代开始转变为梭形,第3代逐渐出现漩涡状排列;骨髓、骨骼肌和软骨膜来源的细胞生长状态良好,可传10代以上,但软骨来源的细胞在第5代后,逐渐退变死亡。骨髓来源的原代细胞部分表达CD29、CD90、CD34,传代后不表达CD34,但CD29、CD90的表达逐代增强;骨骼肌、软骨膜及软骨来源的原代细胞均不表达CD29、CD90和CD34,从第2代开始均表达CD29、CD90,且不断增强;仅原代软骨细胞表达Ⅱ型胶原,至第2代基本不表达;无细胞表达Desmin。4种来源的第3代细胞经诱导均可分化为成骨细胞或成脂细胞。结论 4种来源的干细胞均具有MSCs的特点,但骨髓、骨骼肌、软骨膜来源的干细胞的生长明显强于软骨来源的干细胞。     

去上皮羊膜及其浸提液体外诱导骨髓间充质干细胞的分化

目的观察去上皮羊膜及其浸提液体外诱导骨髓间充质干细胞(Bone marrow mesenchymal stem cells,BMSCs)向上皮细胞的分化,并探讨其机制。方法从胎儿四肢长骨分离BMSCs,扩增后采用流式细胞术分析第3代(P3)细胞表面抗原(CD29、CD34、CD71和HLA-DR)的表达,并用4,6-乙酰基-2-苯基吲哚(DAPI)标记第4代BMSCs(P4-BMSCs)。机械法去除正常胎盘羊膜上皮,制成去上皮羊膜,并制备去上皮羊膜浸提液。将DAPI标记的BMSCs接种于羊膜上,设加或不加表皮细胞生长因子(Epidermal growth factor,EGF)、类胰岛素1号生长因子(Insulin-like growth factor 1,IGF-1)、羊膜浸提液诱导组及细胞爬片对照组,体外诱导培养后,采用免疫荧光组织(细胞)化学染色学法检测各组细胞角蛋白(Cytokeratin,CK)、EGF-R和IGF-1-R的表达,并于诱导后第10天计算CK阳性细胞率。结果原代BMSCs呈典型旋涡状生长,P3细胞表达CD29和CD71,不表达CD34和HLA-DR。羊膜组和细胞爬片组BMSCs在加入EGF或IGF-1诱导后,表达EGF-R和IGF-1-R的时间较未加生长因子的对照组提前2～4 d,表达CK的时间提前2～6 d,单用羊膜组或羊膜浸提液组的表达时间差异无统计学意义(P>0.05);诱导第10天,单用羊膜或羊膜浸提液诱导组的CK阳性细胞表达率明显高于细胞爬片对照组(P<0.05);羊膜与EGF、IGF-1联合诱导组高于单用羊膜组(P<0.05);EGF诱导组高于IGF-1诱导组(P<0.05)。结论羊膜及羊膜浸提液、外源性EGF和IGF-1在体外均可诱导BMSCs向上皮细胞分化,羊膜可能主要通过其所含的细胞因子诱导BMSCs向上皮分化。     

脐血造血干/祖细胞与脂肪干细胞共培养的作用距离研究

设计了一种细胞间距可调的transwell共培养方法,以研究脐带血来源的造血干/祖细胞(HS/PCs)和人脂肪干细胞(human-adipose derived stem cells,h-ADSCs)体外共培养时细胞间作用距离对造血干细胞扩增能力和脂肪干细胞在共培养后干细胞特性的影响.采用不同规格的砂纸打磨孔板的上壁面...     

辐射后A549细胞上清外泌体TMEM88蛋白表达与细胞周期的相关性

目的探讨辐射对肺腺癌A549细胞细胞周期的影响,观察其细胞上清外泌体TMEM88蛋白(transmembrane protein 88)的表达情况。方法取对数生长期肺腺癌A549细胞,按0、0.5、1、1.5、2 Gy剂量(剂量率1.75 Gy/min,300 Mu/min)照射细胞,培养6和12 h后,流式细胞术检测不同辐射剂量对细胞周期的影响;收集细胞上清,超速离心提取外泌体蛋白,Western blot法分析外泌体TMEM88蛋白的表达情况。结果 G2期细胞6 h检测结果显示,与0 Gy组相比,各剂量组细胞比例显著增加(P0.001),且随照射剂量增加,细胞比例增加越明显,除0.5 Gy组与1 Gy组外,其余各组间差异均有统计学意义(P0.001);12 h检测结果显示,G2期细胞比例随照射剂量增加而显著增加,各组间差异均有统计学意义(P0.05)。S期细胞6 h检测结果显示,与0 Gy组相比,0.5、1.0、1.5 Gy组S期细胞比例显著增加(P0.05);12 h检测结果显示,与0、0.5 Gy组相比,1.0、1.5 Gy组S期细胞比例显著增加(P0.05)。随照射剂量的增加,外泌体TMEM88蛋白的表达逐渐降低,6 h检测结果显示,0 Gy组与1.5、2.0 Gy组以及0.5 Gy组与2.0 Gy组相比,差异均有统计学意义(P0.05));12 h检测结果显示,0.5、1.0、1.5、2.0 Gy组与0 Gy组相比,差异均有统计学意义(P0.001)。结论辐射能够诱导肺腺癌A549细胞细胞周期阻滞,并能抑制细胞上清外泌体TMEM88蛋白的表达。     

不同样品处理方法对T淋巴细胞亚群及功能分析的影响

目的研究Ficoll-Hypaque密度梯度离心法、先裂解红细胞后标记抗体、先标记抗体后裂解红细胞3种不同处理方法对T淋巴细胞(T细胞)亚群及功能分析的影响。方法采用3种方法制备样本后,采用流式细胞术检测T细胞表面分子及亚群比例,台盼蓝染色检测细胞存活率,Con A刺激检测细胞活性。结果 Ficoll-Hypaque密度梯度离心法与两种裂解红细胞法相比,T细胞亚群比例差异无统计学意义(P0.05),细胞存活率及细胞活性均较高(P0.05)。两种裂解红细胞法处理样本结果无差异。结论 Ficoll-Hypaque密度梯度离心法适合研究工作,先标记抗体后裂解红细胞的方法更适合临床检验。     

脐带间充质干细胞长期体外培养的生物学特性及遗传稳定性

目的观察脐带间充质干细胞(umbilical cord mesenchymal stem cells,UC-MSCs)体外长期培养的生物学特性及遗传稳定性。方法从剖宫产足月健康新生儿脐带中分离培养UC-MSCs,并连续传代,显微镜下观察细胞形态。分别检测P3和P12代UC-MSCs的增殖能力、免疫表型、向成脂肪细胞和成骨细胞的分化诱导率、衰老情况、成纤维细胞集落形成单位(CFU-F)及染色体核型。结果 P3代UC-MSCs为形态相对均一的梭形贴壁细胞,呈平行排列生长或旋涡状生长;P12代UC-MSCs宽大扁平,贴壁性减退,漂浮细胞增多,胞浆内出现黑色颗粒和空泡;P3和P12代UCMSCs均表达CD73、CD90、CD105,不表达CD34、CD45、HLA-DR;P3较P12代UC-MSCs的细胞增殖能力及向成脂肪细胞分化诱导率均明显升高(P均0.05);向成骨细胞分化诱导率及细胞衰老率均明显降低(P均0.05);成纤维细胞集落数及染色体中期分裂相明显增多(P0.05)。结论长期体外培养的UC-MSCs生物学特性发生改变,遗传学特性稳定,但染色体中期分裂相减少。     

庆阳地区丙型肝炎病毒基因型分布特点及其临床意义

目的探讨庆阳地区丙型肝炎病毒(hepatitis C virus,HCV)基因型分布特点及其临床意义。方法收集庆阳地区289例各种丙型肝炎患者的临床资料及血液样本,采用PCR-荧光探针法检测HCV RNA和基因型,并对检测数据进行统计学分析。结果 289份HCV RNA阳性血清标本中1b型139例(48.1%),2a型136例(47.1%),3a型8例(2.8%),3b型5例(1.7%),未分出型1例(0.3%)。HCV基因型与患者的性别、年龄分布差异有统计学意义(P0.05)。不同感染途径患者的基因型分布差异有统计学意义(P0.05),输血是最主要的HCV感染途径,其次是血液透析。HCV基因2a型组的持续病毒学应答(sustained virological response,SVR)率(77.2%)高于1b组(69.8%),但差异无显著统计学意义(P0.05)。不同基因型的HCV RNA载量差异有统计学意义(P0.05)。1b型患者中肝硬化和肝癌的比例明显高于其他基因型(P0.05)。结论庆阳地区HCV基因型呈多基因型分布特点,主要为1b和2a型,两型比例相当;HCV基因型与患者性别、年龄、感染途径、HCV RNA水平、肝病的严重程度均有相关性。     

Modification of diaphragm-type chlor-alkali cells to ion exchange membrane cells

Ion exchange membrane cell technology, recently developed for producing chlorine and caustic soda, has been applied to the modification of existing diaphragm cells into special IEM cells, termed the MBC^®, which offer a higher energy (electricity and steam) efficiency and a higher product quality than those of diaphragm cells with only a small amount of additional modification cost.     

Photogalvanic cells

An analysis of photogalvanic cells is carried out and applied to a specific system, iron-thionine, with only slight simplifications. The criteria for successful cell design are given and discussed. It is concluded that many formidable obstacles to practical application exist. The principal difficulties are the following: (1) Diffusion to the electrodes and reaction there must be sufficiently rapid to make bulk back reactions unimportant. (2) A means for keeping at least one active species from reaching one electrode must be found. (3) A sufficient range of the solar spectrum must be exploited without increasing the rate of photon absorption to the point where bulk back reaction becomes important. These problems are discussed in some detail and quantitative criteria are presented in terms of absorbed photon flux, cell size parameters, chemical rate constants, exchange current densities, overvoltages and diffusion coefficients.     

Sodium-sulphur cells

The sodium-sulphur battery is reviewed and experimental results are presented. The experimental cells were capable of delivering steady state power densities as high as 50 W.kg^?1 and energy densities as high as 250 W.h.kg^?1. The theoretical open circuit voltage of 2.08 V was observed in all cases. Cell polarization was limited by cell internal resistance, which was attributed largely to the resistance of the β-alumina electrolyte. The “asymmetry effect” is explained in terms of an electrode blockage mechanism involving polysulphides. The sodium-sulphur battery appears to be technically feasible as the power source for an all-electric vehicle.     

Electrochemical impedance spectra of solid-oxide fuel cells and polymer membrane fuel cells

Electrochemical impedance spectroscopy (EIS) is a very useful method for the characterization of fuel cells. The anode and cathode transfer functions have been determined independently without a reference electrode using symmetric gas supply of hydrogen or oxygen on both electrodes of the fuel cell at open circuit potential (OCP). EIS are given for both polymer electrolyte fuel cells (PEFC) and solid oxide fuel cells (SOFC) at current densities up to 0.76 A cm⁻² (PEFC) and 0.22 A cm⁻² (SOFC). With increasing current density the PEFC-impedance decreases significantly in the low frequency range reaching a minimum at 0.4 A cm⁻². At even higher current densities an increasing contribution of water diffusion is observed: the cell impedance increases again. From EIS of SOFC a finite diffusion behavior is observed even at OCP, depending on water partial pressure of the anodic gas supply. This additional element reflects the influence of water partial pressure on the cell potential. The simulation of the measured EIS with an equivalent circuit enables the calculation of the individual voltage losses in the fuel cell.     

Measure of the driving forces of underfilm differential contamination cells and differential aeration cells

Specially designed multilaminar electrochemical sensors (MS) are used to determine the difference in potential between the local anodes and cathodes of corrosion cells that form under protective organic coatings. These MS not only allow quantification of the effect of underfilm contamination and differential aeration on corrosion kinetics but also supply valuable information for a better understanding of the corrosion process mechanism. The use of MS with alternately clean and contaminated laminae clearly shows that differential contamination cells are capable of generating potential differences (driving forces) of hundreds of millivolt, as also occurred with underfilm differential aeration cells.     

非灌流法分离大鼠肝星形细胞及其鉴定

目的采用非灌流法分离大鼠肝星形细胞(Hepatic stellate cell,HSC),并进行鉴定。方法采用非灌流法结合酶消化法分离大鼠肝脏细胞,密度梯度离心进一步分离HSC,油红染色检测HSC胞质中的脂滴,免疫组化法检测细胞中α-平滑肌肌动蛋白(α-Smooth muscle actin,α-SMA)、结蛋白(Desmin)及神经胶质酸性蛋白(Glial fibrillary acidic protein,GFAP)的表达。结果非灌流法结合酶消化法可成功分离大鼠HSC;密度梯度离心纯化的HSC经油红染色,细胞核周围可见红色脂滴;该细胞中α-SMA、结蛋白及GFAP的免疫组化染色结果均呈阳性,细胞着色率可达90%以上。结论成功建立了大鼠HSC的非灌流分离模式,所获得的HSC纯度较高,该方法稳定简便,具有一定的推广应用价值。     

钙钛矿太阳电池的研究进展

介绍了卤铅铵钙钛矿（CH3NH3PbX3,X = Cl、Br、I）的结构及其在新型无机-有机杂化异质结钙钛矿太阳电池中的应用,阐述了钙钛矿太阳电池的结构与工作原理,着重从钙钛矿太阳电池的致密层、钙钛矿吸收层（有骨架层和无骨架层）及有机空穴传输层三个重要组成部分的材料、微结构及制备方法等方面分析了钙钛矿太阳电池的研究进展及存在的问题。并结合不同课题组的研究成果评价了钙钛矿太阳电池各组成部分相应的材料、微结构及制备方法等对太阳电池光伏性能和长期稳定性的影响。此外还介绍并比较了反转结构与柔性太阳电池的光伏性能,简要讨论了钙钛矿太阳电池的各层材料、结构、有毒重金属的替代、长期稳定性等方面的发展趋势。     

Thermal properties of sodium-sulphur cells

The heat capacity and the rate of heat generation of Na/S cells during discharge and charge were determined. The measurements were carried out in a furnace with very low heat loss and low heat capacity (quasi-adiabatic arrangement). A linear relationship between (1/I)(dT/dt) andI, whereI is the discharge or charge current and dT/dt the temperature gradient, was obtained. From these plots the heat capacity of the cell and the entropy term could be determined. It turned out that, due to a steep entropy increase beyond about 80% state of discharge, the heat generation rate increased strongly in this region. During charging, this effect causes a cooling effect at low currents. The data presented here are important for the design of the thermal management system of an electric vehicle battery.