NGF基因重组慢病毒载体的构建及其在人脐带血间充质干细胞的表达

目的:构建神经生长因子(NGF)的慢病毒表达载体,并观察其转染人脐带间充质干细胞后的表达情况。方法:采用实时定量PCR(RT-PCR)方法获取NGF基因编码片段,并将构建的慢病毒载体质粒与包装质粒和包膜质粒共转染293T细胞,包装生产慢病毒。应用相同滴度的慢病毒转导等量间充质干细胞(MSCs),观察转染后细胞的生长形态及生长曲线,再采用RT-PCR、Western Blot方法检测NGF m RNA、蛋白质的表达水平。结果:经PCR、酶切和测序结果证明成功构建NGF基因重组慢病毒载体。同时NGF基因重组慢病毒载体能够成功转染人脐带间充质干细胞,转染率达95.35%,转染后干细胞在NGF m RNA及蛋白质的表达方面较对照组明显升高,同时经倒置显微镜观察及生长曲线实验证实转染后干细胞的生长与对照组相比无明显差异。结论:重组NGF的慢病毒表达载体能够高效的转染人脐带间充质干细胞,基因转染后干细胞的增殖分化能力与未转染细胞差异无统计学意义,可作为一种高效的干细胞转染方法。     

腺病毒载体介导PDX-1在骨髓间充质干细胞中的表达

为研究PDX-1基因在骨髓间充质干细胞中的表达情况及生物学功能的发挥,构建了含PDX-1基因的重组腺病毒载体.酶切PDX-1基因并连入穿梭质粒pAdTrack-CMV.用电穿孔法使穿梭质粒pAdTrack-CMV-PDX-1与病毒骨架质粒pAdEasy-1在大肠杆菌BJ5183中同源重组.利用脂质体介导重组腺病毒载体转染293细胞,包装出完整的腺病毒.分离、培养、扩增骨髓间充质干细胞.用重组腺病毒感染间充质干细胞.用荧光显微镜、RT-PCR、免疫荧光染色等方法检测PDX-1、胰岛素基因及蛋白质的表达,用放射免疫分析法检测转基因细胞分泌胰岛素情况.结果表明:通过测序、PCR、酶切等鉴定PDX-1基因已正确插入穿梭质粒中,并与病毒骨架质粒重组.重组腺病毒滴度为6.3×107PFU/ml.通过荧光显微镜观察证实重组腺病毒可高效感染骨髓间充质干细胞,经RT-PCR、免疫荧光染色证实转染pAd-PDX-1后培养7天的细胞中有PDX-1及胰岛素基因的表达.这些转基因的细胞向胞外分泌的胰岛素量为(15.21±3.50)mIU/L.     

慢病毒重组同源盒基因HOXA4表达载体的构建及其感染人脐带间充质干细胞的实验性研究

目的 构建携带同源基因HOXA4的慢病毒表达载体,并测定其对人脐带间充质干细胞的感染效率.方法 使用酶切及PCR技术从含有HOXA4基因的质粒克隆模版HOXA4-MSCV逆转录载体中获取目的 基因HOXA4,并将HOXA4基因重组到慢病毒载体表达质粒上Lenti-GFP-CTB,通过酶切、测序验证HOXA4基因后,将Lenti-GFP-HOXA4质粒、和辅助包装质粒pRsv-REV、pMDlg-pRRE、PMD2G共同转染人胚胎肾上皮细胞系293T细胞,获得携带HOXA4基因的重组慢病毒Lentiviral-HOXA4;然后感染人脐带间充质干细胞,通过荧光显微镜及流式细胞术检测其感染效率.结果 成功构建携带HOXA4基因的慢病毒表达载体Lentiviral-HOXA4,并获得高纯度的慢病毒浓缩液.经检测病毒滴度达2.11×108 TU/ml.成功转染HOXA4基因的脐带间充质干细胞表达绿色荧光蛋白,当病毒感染复数（MOI）值为60时转染效率最高,达（95.4±4.3）%.结论 成功构建携带人HOXA4基因的慢病毒,并可以在体外有效转染人脐带间充质干细胞.     

hAng-1真核表达载体的构建及其在MSCs中的表达

目的:通过基因重组技术,构建人血管生成素-1(human angiopoietin 1,hAng-1)真核表达载体体系,并将其转染至大鼠的骨髓间充质干细胞(marrow mesenchymal stem cells,MSCs)内进行培养,进而验证hAng-1的表达.方法:将hAng-1编码序列(互补脱氧核糖核酸)通过酶切,插入至pcDNA3.1(+)质粒的多克隆位点,构建质粒pcDNA 3.1 (+)/hAng-1真核表达质粒;重组质粒经脂质体介导转染鼠MSCs.应用逆转录聚合酶联反应(RT-PCR)、蛋白免疫印迹法(Western blot)等方法检测hAng-1的表达情况.结果:pcDNA 3.1 (+)/hAng-1真核表达质粒转染鼠MSCs后,应用流式细胞仪检测,转染效率约为15％.同时应用RT-PCR能够检测出目的基因mRNA,Western blot能够检出hAng-1的蛋白表达.结论:本实验通过基因重组技术,构建的pcDNA3.1 (+)/hAng-1真核表达载体能够在转染的鼠MSCs中表达,且表达较为持续,为hAng-1基因应用于基因治疗的研究奠定了基础.     

靶向DENN-SV基因的shRNA真核表达载体的构建

该研究根据DENN-SV序列及shRNA设计原则,设计四个靶点序列,退火后用DNA重组技术与pRNAi-U6.1/Neo空载体连接,转化到感受态E.coli中。扩增菌株,抽提质粒,进行酶切、DNA测序鉴定。将重组的真核表达载体转染人乳腺癌MCF-7细胞并使用RT-PCR及Western blot检测其抑制DENN-SV mRNA表达的效率,以MTT法绘制生长曲线。测序结果与设计序列相同,并已成功转染进入人乳腺癌MCF-7细胞,可见GFP(绿色荧光蛋白)表达,且都具有抑制作用(P<0.01),DS-1组的抑制效果最好;MTT法绘制生长曲线结果表明,实验组经该载体转染后细胞增殖程度显著减少(P<0.05)。该研究应用RNAi技术成功构建了小干扰RNA重组体,为进一步研究乳腺癌基因治疗奠定了基础。     

腺病毒载体介导PDX-1在骨髓间充质干细胞中的表达

为研究PDX-1基因在骨髓间充质干细胞中的表达情况及生物学功能的发挥,构建了含PDX-1基因的重组腺病毒载体. 酶切PDX-1基因并连入穿梭质粒pAdTrack-CMV.用电穿孔法使穿梭质粒pAdTrack-CMV-PDX-1与病毒骨架质粒pAdEasy-1在大肠杆菌BJ5183中同源重组.利用脂质体介导重组腺病毒载体转染293细胞,包装出完整的腺病毒.分离、培养、扩增骨髓间充质干细胞.用重组腺病毒感染间充质干细胞.用荧光显微镜、RT-PCR、免疫荧光染色等方法检测PDX-1、胰岛素基因及蛋白质的表达,用放射免疫分析法检测转基因细胞分泌胰岛素情况.结果表明:通过测序、PCR、酶切等鉴定PDX-1基因已正确插入穿梭质粒中,并与病毒骨架质粒重组.重组腺病毒滴度为6.3×10⁷ PFU/ml.通过荧光显微镜观察证实重组腺病毒可高效感染骨髓间充质干细胞,经RT-PCR、免疫荧光染色证实转染pAd-PDX-1后培养7天的细胞中有PDX-1及胰岛素基因的表达.这些转基因的细胞向胞外分泌的胰岛素量为(15.21±3.50) mIU/L.     

下调人脐带间充质干细胞Mbd3基因shRNA慢病毒的构建及鉴定

研究构建靶向抑制人Mbd3表达的sh RNA慢病毒颗粒,感染人脐带间充质干细胞并用嘌呤霉素筛选获得Mbd3稳定下调的细胞系,为进一步探讨Mbd3在诱导型多潜能干细胞形成中的作用提供实验基础。研究根据Gene Bank中公布的Mbd3基因序列设计特异性si RNA干扰序列并合成可产生sh RNA的双链DNA,经双酶切后克隆至p LVsh RNA-EGFP(2A)Puro载体上构建慢病毒重组质粒,转化DH5α大肠杆菌PCR检测筛选阳性质粒,利用HEK293Ta包装产生含有Mbd3sh RNA的慢病毒颗粒。通过RT-PCR和Western blot检测慢病毒感染人脐带间充质干细胞(h UC-MSC)后Mbd3的转录和蛋白表达情况,进一步检测重组慢病毒对Mbd3的沉默效果并筛选出最佳抑制效果的sh RNA慢病毒载体。结果显示成功构建并筛选出下调Mbd3的最佳慢病毒干扰载体,慢病毒感染人脐带间充质干细胞48h后于荧光显微镜下可见绿色荧光,经嘌呤霉素筛选9 d后,RT-PCR检测Mbd3表达显著降低,Western blot检测Mbd3蛋白表达明显减少。说明构建的sh RNA重组慢病毒包装成功,具有较高的感染活性,可有效抑制人脐带间充质干细胞Mbd3的表达,为后续研究脐带间充质干细胞跨胚层分化打下前期研究基础。     

人线粒体转录终止因子3基因RNA干扰表达载体的构建筛选与干扰效果评价

目的:构建人线粒体转录终止因子3(MTERF3)基因的短发夹RNA(shRNA)干扰表达载体,并在mRNA和蛋白质水平对其干扰效率进行验证,以检测和筛选出干扰效率最优的shRNA表达载体。方法:根据人MTERF3基因全长cDNA序列,利用Oligoengine在线软件设计4个shRNA序列,合成4条互补寡核苷酸链,退火成双链后克隆至psiU6.1载体,得到4个重组干扰质粒psi-MTERF3-1～psi-MTERF3-4,并通过PCR和DNA测序对其进行鉴定;将重组干扰质粒利用脂质体介导瞬时转染He La细胞,转染48 h后采用real time RT-PCR检测4个干扰质粒对MTERF3 mRNA表达水平的影响,采用Western印迹检测其对MTERF3蛋白表达水平的情况,并筛选出最有效的shRNA干扰质粒。结果:PCR鉴定和DNA测序鉴定证实重组质粒中已插入目的DNA序列;real time RT-PCR和Western印迹结果表明4个重组载体均可以显著降低人MTERF3基因mRNA和蛋白质的表达水平(P0.05),其中以pSi-MTERF3-4的干扰效率最优,对MTERF3 mRNA表达的抑制率为70.1%,对MTERF3蛋白表达的抑制率为72.2%。结论:在人宫颈癌He La细胞系筛选出有效干扰MTERF3基因表达的shRNA序列,构建了针对MTERF3基因的RNA干扰真核表达载体且能够有效抑制目的基因的表达,为进一步研究人MTERF3在宫颈癌发生发展中的作用机制提供了实验基础。     

六种藓类植物茎的比较解剖学研究

通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.     

Cause of Senescence of Nine Sorts of Flowers

The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.     

龙胆科药用植物化学成分的研究现状

龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。     

The effects of glutamine of the maintenance of embryogenic cultures of Cryptomeria japonica

Summary Embryogenic tissues of sugi (Cryptomeria japonica) were induced on a modified Campbell and Durzan (CD) medium containing 1 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 600 mg l⁻¹ glutamine, and subcultured in the medium of the same composition for over 1 yr. This resulted in a mixed culture of embryogenic and non-embryogenic cells. When embryogenic cells were isolated and cultured independently, their capacity to form embryogenic aggregates was lost. Thus, the non-embryogenic cells present within a mixed culture system were essential to the formation of embryogenic aggregates. When embryogenic tissues were isolated and cultured independently on a high glutamine-containing (2400 mg l⁻¹) medium, dry weights and endogenous levels of glutamine increased, and the tissue could generate a large number of embryogenic aggregates. Amino acid analysis of embryogenic and non-embryogenic cells from the maintenance culture indicated a higher level of glutamine was present in the latter. The high endogenous level of glutamine in the non-embryogenic portion of mixed cell masses may be the supplier of glutamine for maintaining the embryogenic property of the tissues.     

Specificity of action of piperidylcholine derivatives as substrates of cholinesterases of various origin

The review deals with study of enzymologic properties of a novel highly specific acetylcholinesterase substrate, N-(β-acetoxyethyl) piperidinium iodomethylate (“piperidylcholine”), and its 30 derivatives that were tested as effectors of cholinesterases of mammals and various species of Pacific squids. It was proven for the first time that responsible for specificity of action was structure of cyclic ammonium grouping of the alcohol part of molecule of the ester substrate. Analysis of specificity is performed based on enzymatic hydrolysis parameters—activity of catalytic center of cholinesterases and bimolecular constant of the reaction rate that are determined at optimal and low substrate concentrations. Among the specially synthesized group of thioester compounds there is revealed one more highly specific acetylcholinesterase substrate—N-(β-acetoxyethyl) piperidinium.     

真菌类遗传学分析的知识结构教学

本文以认知结构理论为指导,讨论了真菌类遗传分析与高等动植物遗传分析的内在联系,认为利用这种内在联系进行教学可收到好的效果并说明了作者的具体教学过程。 Abstract:In the paper, the relationship between genetic analysis of Fungi and genetic analysis of high animal and plant was discussed.A good results were obtained when we adopted this method in the teaching.     

医疗机构合理用药评价模型的构建研究

目的 针对医疗机构的合理用药水平进行评价研究。方法 根据医疗机构合理用药的具体要求,构建医疗机构合理用药评价指标体系,采用基于模糊群决策的方法和多指标评价分析法构建医疗机构合理用药评价模型。结果 构建了基于模糊群决策的医疗机构合理用药评价模型,并通过实例分析证明了评价模型的可行性。结论 建立的基于模糊群决策的医疗机构合理用药评价模型能够对医疗机构的合理用药水平进行科学评价,为提高医疗机构合理用药水平奠定基础。     

Photoregulation of seed germination of wild-type and of an aurea-mutant of tomato

Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m⁻² s⁻¹. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to P_fr.