稳定表达CRFR1的HEK293细胞株建立与功能鉴定

目的建立稳定表达CRFR1的HEK293细胞株,并鉴定cAMP评价体系构建是否成功。方法采用Lipofectamine2000将CRFR1质粒转染至HEK293细胞中,经G418筛选单克隆阳性细胞,采用Western blot技术、RT-PCR法、免疫荧光法证实稳定表达CRFR1细胞株构建成功。并用CRF刺激稳定表达CRFR1的HEK293细胞株,绘制CRF刺激HEK293-CRFR1细胞释放cAMP的量效曲线。结果 Western blot、RT-PCR、免疫荧光结果表明,CRFR1受体在HEK293细胞系中成功表达。cAMP释放量效实验显示,CRF刺激HEK293-CRFR1细胞释放cAMP的EC50为(5.64±0.05)×10-10mol·L-1。结论成功建立了稳定表达CRFR1的HEK293细胞株,并且cAMP含量评价体系构建成功,为研究CRFR1的生物学功能及筛选CRFR1受体靶向药物奠定了基础。     

稳定表达TRPA1通道的HEK-293T细胞模型的建立

目的建立稳定表达TRPA1的HEK-293T细胞模型,并鉴定模型构建是否成功。方法构建TRPA1真核表达质粒,采用脂质体转染法将其转入HEK-293T细胞中,经G418筛选稳定表达株,采用RT-PCR、免疫组化技术,检测HEK-293T细胞TRPA1基因的转录和蛋白的表达。结果经酶切、测序证明,TRPA1基因的真核重组表达质粒已成功构建;PCR、免疫组化检测结果表明,将此重组质粒转入HEK-293T细胞可稳定表达TRPA1基因。结论成功构建了能稳定表达TRPA1通道的HEK-293T细胞株,为体外研究TRPA1生理病理功能和筛选相关TRPA1通道调节剂奠定了基础。     

HEK293 cell line: a vehicle for the expression of recombinant proteins

The HEK cell line has been extensively used as an expression tool for recombinant proteins since it was generated over 25 years ago. Although of epithelial origin, its biochemical machinery is capable of carrying out most of the post-translational folding and processing required to generate functional, mature protein from a wide spectrum of both mammalian and non-mammalian nucleic acids. Though popular as a transient expression system, this cell type has also seen wide use in stably transfected forms (i.e. transformed cells) to study a variety of cell-biological questions in neurobiology. The principal attributes which have made the HEK cell a popular choice among electrophysiologists to study isolated receptor channels include; its quick and easy reproduction and maintenance; amenability to transfection using a wide variety of methods; high efficiency of transfection and protein production; faithful translation and processing of proteins; and small cell size with minimal processes appropriate for voltage-clamp experimentation. These, and other attributes, also mean that complementary biochemical/cell biological evaluations of expressed proteins can be performed in concert with functional analyses to establish detailed pharmacological and biophysical profiles for the action of new drugs and their targets. The increased amount of sequence information available from the human genome has placed greater emphasis upon heterologous cell expression systems as targets for high throughput structure-function evaluation of novel drug targets and disease markers. Here we have highlighted some of the innate characteristics of the HEK cell in order that its suitability as a vehicle for the expression of a gene product can be assessed for particular needs. We have also detailed some of the standard methods used for transfection and obtaining functional data from electrophysiological recording techniques.     

ABCB1(G1199A)基因稳定转染HEK293细胞株的建立

目的:将ABCB1(G1199A)突变型和野生型基因分别转入HEK293细胞,建立P-糖蛋白稳定表达细胞株。方法:以野生型ABCB1基因的cDNA为模板质粒,采用PCR点突变的方法合成突变的ABCB1(1199A)基因;在慢病毒的介导下,将实验室构建的pLVX-ABCB1-PGK-Puro和pLVX-ABCB1-mut-PGK-Puro重组质粒转染HEK293细胞,经嘌呤霉素筛选稳定表达的细胞;通过流式细胞术检测P-糖蛋白的表达、RT-PCR检测ABCB1基因的转录水平、CCK-8方法测定外源基因对HEK293细胞增殖的影响。结果:流式细胞术证实P-糖蛋白在HEK193细胞中稳定过表达,RT-PCR确定转染细胞中存在ABCB1(G1199A)基因mRNA的过表达,成果获得ABCB1(G1199A)野生型和突变型基因的稳定表达细胞株。结论:成功建立两种ABCB1(G1199A)稳定表达的HEK293细胞株,为该酶的功能研究奠定了基础。     

胰岛素样生长因子1稳定表达CHO细胞株的建立

目的 建立稳定的高效表达胰岛素样生长因子1(IGF-1)的中国仓鼠卵巢细胞株(CHO),以便于大量生产纯化IGF-1蛋白.方法 采用脂质体将IGF-1的表达载体pSec-IGF-1导入CHO-K1细胞中.转染后用含潮霉素B(hygromycin B)的选择性培养液进行筛选,挑取耐药克隆,收集细胞培养上清,用Western blot法及ELISA法进行检测,并用免疫组化法对阳性克隆进行分析.结果 转染细胞在选择性培养液中生长出多个耐药克隆,Western blot检测示8个克隆表达上清出现与预计值相符的约7.7kDa的特异性条带;ELISA结果显示有2株表达量在2.0μg/ml以上;免疫组化检测,筛选到的阳性克隆细胞有IGF-1的表达.结论 建立了稳定的高效表达IGF-1的CHO细胞株.     

pEGFP-NTCP稳定转染HEK293细胞系的建立及鉴定

目的高效快速地建立稳定高表达钠离子-牛磺胆酸共转运多肽(sodium taurocholate cotransporting polypeptide,NTCP)的HEK293细胞系。方法构建可表达EGFP-NTCP融合蛋白的p EGFP-NTCP重组质粒,并利用Fu GENE 6转染试剂将重组质粒转染至HEK293细胞中。用荧光显微镜观察绿色荧光蛋白表达情况,挑选转染细胞进行14 d G418筛选和单克隆培养,以获得稳定转染细胞株。用RT-PCR法、qRT-PCR法和Western blot技术检测稳定转染细胞及正常细胞中NTCP mRNA和蛋白的表达情况,并进一步用超高效液相色谱-串联质谱法(UPLC-MS/MS)考察稳定转染细胞的牛磺胆酸摄取能力。结果使用本文优化的方法,细胞转染率可达90%。RT-PCR、qRT-PCR、Western blot和牛磺酸摄取实验结果显示:相对于正常组,在荧光显微镜下呈绿色荧光的转染细胞;其NTCP表达均显阳性(P<0.01);且稳定转染细胞的牛磺胆酸摄取能力明显升高(P<0.05)。结论高效快速地建立了稳定高表达NTCP的HEK293细胞系,为胆酸衍生物摄取机制研究奠定了基础。     

Changes in ultrastructure and endogenous ionic channels activity during culture of HEK 293 cell line

Human embryonic kidney (HEK) 293 cells were characterised as an expression system for voltage-activated cationic channels. Current density for cationic channels intrinsically expressed in HEK 293 cells as well as cell ultrastructure was described after 7-11, 29-30 and 49-63 days of cell culture. Slowly activating outward potassium current with the current density varying between +10 and +26 pA/pF was observed in 72% to 95% of investigated cells. Rapidly inactivating outward potassium current with the current density varying between +7 and +10 pA/pF was present in 38% to 48% of all cells. 30% of cells exhibited voltage-activated calcium channel with the current density less than -1 pA/pF. Tetrodotoxin-sensitive sodium current with amplitudes between -1.4 and -2.2 pA/pF was initially present in 5% of cells, nevertheless, after 49-63 days of cell culture this proportion increased to 35%. Ultrastructure of HEK 293 cell surface, but not of cell's interior changed during cell culture. The longer the time after thawing the more microvilli and protrusions appear on the cell surface. Irregular cell contours hinder the cells to appose and only small patches of membranes form attachments. Staining of cells with a polycationic dye ruthenium red initially increased and decreased again following prolonged period of time in culture indicating regression of negatively charged layers of the cell surface coat. We suggest that the optimal time window for patch clamp experiment is between days 7 and 63 of cell culture due to alterations of cell surface.     

稳定表达大麻受体2的CHO细胞株的构建

目的建立稳定高效表达人重组大麻受体2(CB2)的中国仓鼠卵巢(CHO-K1)细胞株,为体外高通量筛选CB2激动剂和拮抗剂奠定基础。方法通过脂质体介导的方法将构建的表达载体pcDNA3.1(+)-CB2转染入CHO-K1细胞中,然后用含G418的选择性培养液进行筛选,挑取耐药克隆;培养并收集耐药克隆细胞,用RT-PCR方法做进一步筛选;序列测定鉴定整合基因的序列;筛选的阳性克隆用放射性配体-受体结合实验进行进一步的鉴定和受体活性分析。结果转染细胞在含G418的选择性培养基中生长出28个耐药单克隆,用RT-PCR方法检测出17个CB2mRNA表达量较高的阳性克隆;RT-PCR扩增片段测定鉴定正确;挑选其中最优的克隆进行放射性配体-受体结合实验,结果显示,表达受体具有与CB2激动剂WIN55212-2特异结合的活性,其Kd和Bmax值分别(1.21±0.47)nmol.L-1和(3.12±0.7)nmol.g-1蛋白,这一结果与天然CB2的特性相似。结论建立了稳定高效表达人重组CB2的CHO-K1细胞株。     

稳定高效表达人血栓调节蛋白的CHO细胞株的建立

目的:构建稳定高效表达人血栓调节蛋白(human thrombomodulin,hTM)的CHO细胞株,以便于大量生产纯化hTM蛋白。方法:利用脂质体li-pofectamine 2000将包含hTM基因全长序列的重组表达质粒pThr402转染CHO细胞。转染后用G418的选择性培养液筛选、挑取抗性克隆。采用流式细胞术和Western blotting检测hTM在CHO细胞膜表面的表达情况,筛选建立稳定高效表达hTM的CHO细胞株并对其稳定性进行观察。结果:重组表达质粒pThr402转染CHO细胞后,流式细胞术证实hTM稳定高效表达于随机挑选的5个抗性克隆细胞株的细胞膜表面,但表达量有差异。Western blotting分析检测显示hTM表达量较高的CHO-TM1、CHO-TM4与CHO-TM5细胞株的细胞裂解液出现了与预期值相符的约105000的特异性条带。CHO-TM5已经经过冻存复苏前后各20次传代,且无论有无G418选择压力存在,hTM表达水平无明显差异。结论:成功构建了稳定高效表达hTM的CHO细胞株,可望获得大量蛋白,为进一步研究hTM的生物学功能以及制备和筛选抗hTM的单抗开辟新的途径。     

Establishment and use of a cell line expressing HSV-1 thymidine kinase to characterize viral thymidine kinase-dependent drug-resistance

To understand the mechanisms of antiviral drug resistance and to have a system to examine the cytotoxicity of herpes simplex virus type 1 (HSV-1) inhibitors that are thymidine kinase (TK)-dependent, we have constructed a plasmid pFTK1 by inserting a DNA fragment containing the TK gene of HSV-1 strain F into the eukaryotic expression vector pcDNA3.1/His A. TK-deficient 143B cells were transfected with this vector and neomycin-resistant cells were selected. Cell survival in HAT medium and TK activity of the cell lysates were examined to ascertain HSV-1 TK expression. A cell line expressing the viral TK gene, FTK143B (FTK), was established and used for characterization of two laboratory-derived TK-deficient drug-resistant HSV-1 mutants of strain F. The antiviral activities of several drugs, mostly nucleoside analogues, were compared in the Vero, 143B and FTK cell culture systems. We showed that both mutant viruses lost their resistance to acyclovir and to other HSV-1 TK-dependent compounds in FTK cells but not in Vero and 143B cells. Significantly increased cytotoxicity of ganciclovir and (E)-5-(2-bromovinyl)-2'-deoxyuridine was also observed in the FTK cells. This HSV-1 TK gene-transfected cell model is a useful tool to rapidly determine HSV-1 drug resistance at the viral TK level.     

HEK293细胞中细丝蛋白-C对α_(1A)-肾上腺素受体介导细胞外信号调节激酶磷酸化作用的影响

目的　寻找与α1A 肾上腺素受体 (α1A AR)相互作用的胞浆内非G蛋白 ,研究蛋白对受体信号转导的影响。方法　应用酵母双杂交技术 ,以人α1A AR胞浆内C末端 (α1A AR CT)为诱饵 ,筛选人脑cDNA文库 ,用 5 溴 4 氯 3 吲哚半乳糖苷 (X Gal)定性分析及邻硝基苯基 β D 半乳糖苷 (ONPG)定量分析对筛选出的阳性克隆细丝蛋白 C(FLNC)进行确证。采用脂质体转染及蛋白免疫印迹技术探讨人胚胎肾 2 93(HEK2 93)细胞中FLNC对α1A AR信号转导通路的影响。结果　①缺陷培养基筛选出FLNC的C末端部分片段可以与α1A AR CT在酵母中结合。②X Gal定性分析中 ,FLNC与α1A AR CT的共转子菌落 6h即呈现蓝色 ,而对照菌落颜色无变化 ;经ONPG定量分析发现 ,FLNC与α1A AR CT的共转子中 β 半乳糖苷酶的活性大约是对照的 2～ 3倍(P <0 .0 1)。③编码FLNC的C末端片段的质粒瞬时转染于稳定表达全长α1A AR的HEK2 93细胞中 ,可以明显增强去氧肾上腺素 ( 10 μmol·L- 1,30min)激动α1A AR介导的细胞外信号调节激酶 (ERK1/ 2 )磷酸化作用。结论　FLNC的C末端部分片段可以与α1A AR CT在酵母中结合 ,并且增强HEK2 93细胞中α1A AR介导ERK1/ 2磷酸化的作用     

稳定表达RASSF1A基因肝癌细胞株的建立

目的建立稳定表达RASSF1A基因的肝癌细胞株。方法真核表达载体pcDNA3.1(+)RASSF1A经阳离子脂质体介导转染肝癌细胞株QGY-7703和Hep3B,通过G418筛选阳性细胞克隆,逆转录-聚合酶链反应(RT-PCR)和Western blot鉴定目的基因的表达。结果 (1)QGY-7703,Hep3B细胞株的G418最佳筛选浓度分别为800 μg／ml和400 μg／ml;(2)QGY-7703和Hep3B细胞株各获得2个稳定表达RASSF1A基因的细胞克隆。结论成功建立了稳定表达RASSF1A基因的肝癌细胞株。     

稳定表达GFP-LC3蛋白的THP-1细胞系的构建

摘要：目的 构建稳定表达GFP-LC3的人急性单核细胞白血病细胞（THP-1）。方法 采用pCDH-CMV-GFP LC3-EF1α-puro转染293T细胞构建慢病毒质粒系统,获取的慢病毒感染THP-1细胞,用嘌呤霉素（Puromycin）筛选 稳定表达GFP-LC3蛋白的细胞系。通过Western blot和流式细胞术检测THP-1细胞中GFP-LC3蛋白的表达,并利用 该稳定表达细胞系观察饥饿和雷帕霉素诱导时细胞发生的自噬变化。结果 筛选得到稳定表达GFP-LC3蛋白的 THP-1细胞系,在倒置荧光显微镜下观察可见绿色荧光。Western blot和流式细胞术检测证实了GFP-LC3融合蛋白 的表达。激光共聚焦法和Western blot均证实饥饿和雷帕霉素可以诱导自噬的发生,且GFP-LC3融合蛋白可以反映 内源LC3蛋白的变化,包括蛋白聚集和发生剪切修饰。结论 应用慢病毒质粒系统成功构建了高效稳定表达GFP LC3蛋白的THP-1细胞系,从而为后续利用GFP-LC3融合蛋白研究自噬变化提供了细胞模型。     

稳定表达siRNA-NUAK1基因95D细胞系的建立

目的建立稳定表达siRNA-NUAK1基因的人肺巨细胞高转移株95D细胞系,为研究NUAK1在肺癌细胞转移侵袭中的作用机制提供基础。方法利用脂质体把pGCsilencerU6/GFP/Neo-RNAi-NUAK1重组质粒转染95D肺癌细胞,G418筛选稳定转染细胞系,从中挑出单克隆,分别通过荧光显微镜和RT-PCR法鉴定单克隆细胞和NUAK1基因的转染、抑制效果。结果从稳定转染细胞中,成功挑出单细胞克隆3株,其中2株细胞的NUAK1基因的表达被显著抑制。结论利用siRNA技术成功建立了稳定表达siRNA-NUAK1基因的95D细胞系,为研究NUAK1因子与肺癌转移侵袭的关系及机制提供了细胞模型。     

Establishment of MDR1-knockout human induced pluripotent stem cell line

Multiple drug resistance 1 (MDR1) is highly expressed in various organs, including the liver, small intestine, and blood–brain barrier (BBB). Because MDR1 plays important roles in the excretion of many drugs, it is necessary to evaluate whether drug candidates are potential substrates of MDR1. Recently, many researchers have shown that human induced pluripotent stem (iPS) cell-derived differentiated cells such as hepatocytes and enterocytes can be applied for pharmacokinetic testing. Here, we attempted to generate MDR1-knockout (KO) iPS cell lines using genome editing technology. The correctly targeted human iPS cell lines were successfully obtained. The expression levels of pluripotent markers in human iPS cells were not changed by MDR1 knockout. The gene expression levels of hepatic markers in MDR1-KO iPS-derived hepatocyte-like cells were higher than those in undifferentiated MDR1-KO iPS cells, suggesting that MDR1-KO iPS cells have hepatic differentiation capacity. In addition, MDR1 expression levels were hardly detected in MDR1-KO iPS cell–derived hepatocyte-like cells. We thus succeeded in establishing MDR1-KO iPS cell lines that could be utilized for pharmacokinetic testing.     

RNA干扰沉默DDX1基因的胶质瘤细胞系的建立

目的以短发夹核糖核酸(RNA)慢病毒载体建立DEAD-box解旋酶1(DDX1)基因稳定沉默的胶质母细胞瘤细胞株。方法针对DDX1基因设计2组短发夹RNA序列,退火形成的双链DNA与线性p LKO. 1-puro-e GFP质粒载体连接,构建慢病毒质粒载体,测序正确后进行慢病毒包装;将获得的重组慢病毒转染人胶质瘤U251细胞,转染细胞分为对照组和干扰组,对照组转染对照慢病毒(sh NC);干扰组转染慢病毒载体p LKO. 1-puro-e GFP-shRNA-DDX1(sh DDX1-1,sh DDX1-2)。用荧光显微镜观察绿色荧光蛋白表达,进行嘌呤霉素抗性筛选;用实时定量聚合酶链式反应(PCR)、蛋白免疫印迹法检测转染后U251细胞中DDX1 mRNA及蛋白表达。结果测序证实成功构建对照组和靶向DDX1基因的RNA干扰(RNAi)慢病毒载体,病毒悬液滴度均> 3×10~8TU·m L^-1。荧光显微镜下观察显示,对照组和干扰组转染效率高于85%;嘌呤霉素筛选后,干扰组sh DDX1-1、sh DDX1-2中DDX1 mRNA的抑制率分别为85. 44%和71. 66%,DDX1蛋白表达水平分别下降了99. 1%和96. 7%,均较对照组(100%)显著降低(均P <0. 01)。结论成功构建沉默DDX 1基因的胶质瘤细胞系,为研究DDX1对胶质瘤生物学行为的影响提供细胞模型。     

Examination of signal transduction pathway of stimulated B1 and B2 kinin receptors; MAP kinase pathway to AP-1 translocation in HEK 293 cells

B1 or B2 kinin receptor-overexpressing HEK293 cells were stimulated with des-Arg9-BK or BK, respectively. Each agonist induced translocation of AP-1 into the nuclear fraction as well as activation of MAP kinases in each cells. MAP kinase inhibitor PD98059 suppressed translocation of AP-1 and agonist-induced MAP kinase activation in both cells. These results indicate that stimulation of B1 or B2 receptor expresses a feature of the signal transduction pathway of MAP kinase activation to translocation of AP-1. This signal transduction pathway of HEK cells through B1 and B2 receptors may be similar in response to respective agonists.