共查询到20条相似文献,搜索用时 0 毫秒
1.
By transfecting an Oct-4 expression plasmid into embryonic stem cells (ES cells), the ES-O cell line was constructed, which sustained the expression of Oct-4 gene when induced by retinoic acid. Forced expression of Oct-4 gene could not sustain the stem property of ES-O cells without the differentiation inhibiting factor LIF, but if LIF exists, forced expression of Oct-4 gene could enhance the ability to sustain the undifferentiation state and inhibit cell differentiation induced by retinoic acid. It was indicated that Oct-4 must cooperate with LIF to sustain the undifferentiation state of ES cells. During the cell differentiation, ES-O cells tend to differentiate into neural cells, suggesting that forced expression of Oct-4 gene may be in relation with the differentiation of neuroderm. 相似文献
2.
SHANGDeshu FANGWengang CHENYuhua 《科学通报(英文版)》2005,50(5):421-424
We have previously identified an E. coli determinant, ibeB gene locus contributing to invasion of human brain microvascular endothelial cells. In the present study, we established embryonic stem (ES) cell lines overexpressing IbeB and found that exogenic ibeB gene could start-up expression of a neural stem cell specific marker, nestin, and give rise to polar changes. In analysis of IbeB location, it was found that GFP-IbeB fusion protein targeted at the ES cell nucleus. These data suggests that ibeB gene may play an important role in the regulation of nestin expression. 相似文献
3.
Properties and applications of embryonic stem cells 总被引:1,自引:0,他引:1
Mouse embryonic stem (ES) cells are pluripotent cells derived from the early embryo and can be propagated stably in undifferentiated state in vitro. They retain the ability to differentiate into all cell types found in the embryonic and adult body in vivo, and can be induced to differentiate into many cell types under appropriate culture conditions in vitro. Using these properties, people have set up various differentiated systems of many cell types and tissues in vitro. Through analysis of these systems, one can identify novel bioactive factors and reveal mechanisms of cell differentiation and organogenesis. ES cell-derived differentiated cells can also be applied to cell transplantation therapy. In addition, we summarized the features and potential applications of human ES cells. 相似文献
4.
利用脂质体转染法,将真核表达质粒pcDNA3.1-Sox9导入L6胞中.通过细胞增殖检测、细胞形态学观察、标志基因表达分析和甲苯胺蓝染色等方法分析Sox9基因转染对L6细胞增殖和向成软骨方向分化的诱导作用.结果表明,Sox9基因转染对L6细胞的增殖能力没有影响,但能明显抑制L6细胞相互融合形成肌管.和对照相比,Sox9基因转染后,细胞成肌分化标志基因Myf5的表达受到明显抑制,而成软骨分化标志基因Ⅱ型胶原(type Ⅱ collagen ,Col2a1)和蛋白聚糖(Aggrecan,Agg)的表达显著 相似文献
5.
本文采用MTT法,观察不同浓度辛伐他汀(0,1,3,10,30 and 100μmol/L)对C2C12细胞活力的影响,并通过定量RT-PCR方法对utrophin和TNF-α基因的mRNA的表达进行了研究.随着辛伐他汀浓度和作用时间的增加,C2C12细胞的活力在降低;不同浓度辛伐他汀对utrophin和TNF-α的mRNA表达具有影响作用,为阐明辛伐他汀的肌毒性作用机理提供了新的思路. 相似文献
6.
胚胎干细胞(embryonic stem cells,ES)在体外分化培养条件下可以分化出各种组织细胞,其中包括心肌细胞。ES细胞在体外向心肌细胞分化与体内完整胚胎心肌发育过程相符合。该细胞在体外分化过程中顺序表达心肌细胞特有结构蛋白和离子通道,如肌球蛋白轻链和重链、特异性肌动蛋白、电压依赖性Ca^2 通道、K^ 通道等。ES细胞分化来源的心肌细胞具有体内心肌细胞的生理学特点,如产生的动作电位、表现自发性收缩等。因此,ES细胞是研究心肌细胞发育分化机制及鉴定其关键基因的理想模型。 相似文献
7.
EGFP-IgG4融合基因真核表达载体的构建及其表达 总被引:1,自引:0,他引:1
构建增强型绿色荧光蛋白(Enhanced Green Fluorescent Protein, EGFP)和IgG4基因的融合蛋白真核表达载体pMM-EGFP-IgG4/WG,转染至中华仓鼠卵巢细胞(Chinese Hamster Ovary,CHO)中成功表达,并发出绿色荧光,证明pMM-EGFP-IgG4/WG是一种良好的生产分泌型外源融合蛋白的阳性对照. 相似文献
8.
9.
原生殖细胞(PGCs)是配子的始祖细胞,它可发育演变生成卵细胞或精子细胞.上世纪90年代发展了体外培养PGCs技术,现在PGCs已能通过体外培养形成多潜能干细胞(ES),对于研究体外分化机制和细胞治疗具有重要意义.文章通过对静宁鸡种蛋进行36~82 h孵化,并对其血涂片经PAS染色后,在显微镜下观察其原生殖细胞(PGCs)的形态结构,以便为鸡的胚胎干细胞分离培养奠定基础.实验结果:原生殖细胞呈圆形或卵圆形,明显较其他细胞大2~4倍,PGCs的细胞核颜色较深,偏向一侧,后期常聚成一团. 相似文献
10.
应用慢病毒短发夹RNA(short hairpin RNA,shRNA)转染的方式构建了阳离子转运蛋白样蛋白1(cation transport regulator-like protein 1,CHAC1)基因沉默SU-DHL-8细胞株模型,用于研究CHAC1基因对青蒿素细胞毒活性的影响.研究了青蒿素对弥散性大B细胞淋巴瘤SU-DHL-8细胞增殖的抑制作用及作用后CHAC1基因及蛋白的表达情况.应用小干扰RNA(small interfering RNA,siRNA)沉默SU-DHL-8细胞株内的CHAC1基因.采用慢病毒转染的方法构建CHAC1基因沉默的SU-DHL-8细胞株.采用实时荧光定量核酸扩增检测系统(real-time quantitative PCR detecting system,qPCR)、3-(4,5-二甲基噻唑-2)-2,5-二苯基四氮唑溴盐(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide,MTT)活性测定法和蛋白免疫印迹(Westen blot)的方法检测沉默效果以及CHAC1基因对青蒿素细胞毒活性的影响.成功构建了稳定沉默CHAC1基因的稳转细胞株,并初步探讨了CHAC1基因对青蒿素抑制弥散性大B细胞淋巴瘤SU-DHL-8细胞增殖的影响. 相似文献
11.
Hepatocyte transplantation and bioarUficial liver (BAL) as alternatives to liver transplantation offer the possibility of effective treatment for many inherited and acquired hepatic disorders. Unfortunately, the limited availability of donated livers and the variability of their derived hepatocytes make it difficult to obtain enough viable human hepatocytes for the hepatocyte-based therapies. Embryonic stem cells (ESCs), which could be isolated directly from the blastocyst inner cell mass, have permanent self-renewal capability and developmental pluripotency and therefore might be an ideal cell source in the treatment of hepatic discords. However, differentiation of hESCs into hepatocytes with significant numbers remains a challenge. This review updates our current understanding of differentiation of ESCs into hepatic lineage cells, their future therapeutic uses and problems in liver regeneration. 相似文献
12.
13.
Tet-control system is developed to tightly control target gene expression in mammalian cells by using the regulatory elements
of tetracycline-repressor of the transposor Tn10 fromE. coli. We have transfected reverse tetracycline-controlled transactivator gene (rtTA) into genome of Jurkat cells and established two Jurkat tet-on cell lines. Induction of luciferase reporter activity with
doxycycline, a tetracycline derivative, is dose-dependent with a peak value of 32-fold increment. Establishment of Jurkat
tet-on cell lines greatly facilitates quantitative studies on target gene functions in the cells. 相似文献
14.
概述了不同类群动物原始生殖细胞(primordial germ cells,PGCs)的起源和迁移路径.介绍了当前有关不同类群动物PGCs在胚胎发育中与迁移有关的因子和基因的功能,这些因子和基因包括细胞外基质中的生物大分子纤粘连蛋白(fibrbonectin)、Tenascin-C、层粘连蛋白(laminin),Foxc1基因、JAK/STAT信号通路、信号分子STAT 和RAS、基质细胞衍生因子-1(stromal cell-derived factor-1,SDF-1)、F-肌动蛋白(F-actin)等.评述了PGCs迁移研究中存在的问题,认为众多调控因子与PGCs迁移的关系虽已被揭示,但各因子对PGCs详细作用机制及其相互联系、不同物种PGCs迁移的调控因子之间的同源性及如何把单一的作用效果整合起来等问题有待解决. 相似文献
15.
《科学通报(英文版)》1995,40(23):1992-1992
16.
17.
Traditional image segmentation algorithms exhibit weak performance for plant cells which have complex structure. On the other
hand, pulse-coupled neural network (PCNN) based on Eckhorn’s model of the cat visual cortex should be suitable to the segmentation
of plant cell image. But the present theories cannot explain the relationship between the parameters of PCNN mathematical
model and the effect of segmentation. Satisfactory results usually require time-consuming selection of experimental parameters.
Meanwhile, in a proper, selected parametric model, the number of iteration determines the segmented effect evaluated by visual
judgment, which decreases the efficiency of image segmentation. To avoid these flaws, this note proposes a new PCNN algorithm
for automatically segmenting plant embryonic cell image based on the maximum entropy principle. The algorithm produces a desirable
result. In addition, a model with proper parameters can automatically determine the number of iteration, avoid visual judgment,
enhance the speed of segmentation and will be utilized subsequently by accurate quantitative analysis of micro-molecules of
plant cell. So this algorithm is valuable for theoretical investigation and application of PCNN. 相似文献
18.
19.
20.
Erythropoietin (EPO) genomic gene was cloned and its expression vector pOP13/EPO was constructed. CHO_K12 cell was transfected by this vector using lipofectin method. A stable expression cell strain C10 cell with the EPO production at 160IU/d in 10\+6 cells were obtained at 400 μg/mL G418. Based on the C10 cell, another vector pHY/dhfr (dihydrofolate reductase) that carries a dhfr gene and a selecting marker of hygromycin B resistant gene was transferred to this cell. Several cell clones were obtained at 200 μg/mL hygromycin B. These cell clones that can express both EPO gene and exogenous dhfr gene were selected under the progressively increased concentration to 1 μmol methotrexate(MTX). Some high EPO expression cell clones were obtained, the highest expression was 2 400 IU/d in 10\+6 cells, 15 times higher than that without MTX pressure. Then, a method of EPO high expression by using un_dhfr negative cell was primarily established. EPO bioactivity was found by using TF_1 cell. 相似文献