胰十二指肠同源框基因-1在骨髓来源nestin阳性细胞的转染及表达

目的 将真核表达载体pEGFP-C1-PDX-1转染大鼠骨髓来源nestin阳性细胞,并对其转染条件进行优化以获得较高效率.方法 将已构建好的重组载体转染骨髓来源nestin阳性细胞,改变DNA的量、转染后培养基中的血清浓度,在荧光显微镜下观察荧光并计算转染效率;转染后48 h用RT-PCR检测目的 基因的表达情况.结果 质粒2～10 μg获得最佳的转染效率,提高转染后培养基的血清浓度可提高转染后细胞存活率及转染效率.RT-PCR检测转染后骨髓来源nestin阳性细胞有PDX-1表达.结论 通过优化转染条件提高了pEGFP-C1-PDX-1转染大鼠骨髓来源nestin阳性细胞的效率,为其成为组织工程的种子细胞提供了实验依据.     

淋巴细胞不同转染方法比较

目的:用病毒转染和非病毒转染方法将质粒载体转染进淋巴细胞,比较各种方法转染淋巴细胞的效率,确定适合淋巴细胞最佳转染方法。方法:分别用脂质体转染法,电穿孔转染法,慢病毒感染法,核转染法将构建好的酪氨酸羟化酶(TH)基因干扰质粒转染小鼠淋巴细胞,24小时后经荧光显微镜观察增强型绿色荧光蛋白(EGFP)表达水平,确定转染率。结果:核转染法转染TH基因干扰质粒进入淋巴细胞的效率明显高于其他转染和感染方法,24小时后通过观察EGFP的表达确定转染效率可达50%~60%。结论:核转染方法是转染免疫细胞的有效手段,是体外分子生物学方法研究免疫功能的理想手段。     

High-efficiency transfection of short hairpin RNAs-encoding plasmids into primary hippocampal neurons

The transfection of expression constructs encoding a variety of transgenes is a widely used method to study gene function in cultured cells. Especially when the efficiency of the knock-down of target proteins via small interfering RNAs (siRNAs) is to be determined by quantitative Western blotting, large proportions of untransfected cells compromise the analysis. Achieving high transfection efficiencies in postmitotic cells, such as neurons, poses a particular problem in that these cells cannot be selected for the expression of the transgene following transfection. It is therefore important to develop protocols that allow for the highly efficient transfection of these cells. In the present study, we identify three important parameters that prove especially useful for chronically difficult to transfect short hairpin RNA (shRNA)-encoding plasmids: the amount and quality of the plasmid DNA used and the use of new nucleofection programs. Combining those changes increases the rate of transfected cells from less than 5% to up to approximately 80%. Importantly, these high transfection efficiencies can be obtained while maintaining good cell viability and normal cellular development. Taken together, these improvements allow for a detailed biochemical and phenotypical analysis of neurons that have been nucleoporated with a wide variety of shRNAs.     

Anti-tumor Immunity of Gene Vaccine with Nucleofection Technology

OBJECTIVE To observe enhancement of anti-tumor immunity by gene vaccine using nucleofection technologyMETHODS The technique of nucleofection was used to transfer effectively plasmid DNA into immature dendritic cells (iDCs); we studied immune responses regulated by DNA vaccine using real-time quantitative polymerase chain reaction (PCR) and western-blotting to optimize the follow-up lymphocyte activation. The anti-tumor capacity of lymphocytes primed by DCs was analyzed using lactate dehydrogenase with a non-radioactive cytotoxicity assay.RESULTS Human monocyte-derived dendritic cells (hMoDCs) were induced by interleukin (IL)-4 and granulocyte-macrophage colonystimulating factor (GM-CSF) in vitro from human monocytes for 5 or 6 days. DNA vaccine was transfected to iDCs with high transfection (35.73%) using nucleofection. Compared with the iDC group, the expression of Th1 cell cytokine IL-12, IL-18 and Th2 cell cytokine IL-4 increased after stimulation. CD86 and CD83 were upregulated compared with non-nucleofected groups 48 hours after nucleofection with DC-pVAX-PRA. The result of the cytotoxicity assay showed that DCs-pVAX-PRA primed non-adherent peripheral blood mononuclear cells (PBMCs) exhibit their highest cytotoxicity against target cells.CONCLUSION The results show that DNA vaccine was transfected to iDC with high transfection efficiency using nucleofection, priming autologous lymphocytes for anti-tumor immunity by upregulated expression of co-stimulatory molecules, adhesion molecules and cytokines. These results provided a basis to explore the molecular mechanism of DNA vaccine in vivo.     

猪naive-like诱导性多能干细胞系的建立及红色荧光蛋白标记

目的：建立猪naive-like诱导性多能干(induced pluripotent stem,iPS)细胞系,并对其进行红色荧光标记,为通过示踪猪naive iPS细胞发育和分化的相关研究奠定基础。方法：首先利用核转染技术向巴马小型猪胎儿成纤维细胞(porcine embryonic fibroblast,PEF)中转入鼠源OCT4、SOX2、KLF4和c-MYC转录因子表达载体TetO-FUW-OSKM,并同时转入激活表达载体FUW-M2rtTA,采用白血病抑制因子(leukemia inhibitory factor,LIF)结合碱性成纤维细胞生长因子(basic fibroblast growth factor,bFGF)的培养体系进行培养,通过在培养液中添加盐酸多西环素(doxycycline hyclate,DOX) 进行诱导,建立起猪iPS细胞系,并对细胞系的多能性进行鉴定。在此基础上,向iPS细胞系转入红色荧光蛋白表达载体,对其进行标记,并鉴定被红色荧光标记后的细胞是否仍然具有多能性。结果：所建立的iPS细胞系克隆呈三维立体生长,可以进行单细胞传代培养至30代以上,核型正常,碱性磷酸酶染色呈阳性,表达多种干细胞多能因子,利用LIF/STAT3信号通路维持其增殖,体外可分化形成表达三胚层相关基因的类胚体,为猪naive-like iPS细胞系。成功对所建立的iPS细胞系进行红色荧光标记,碱性磷酸酶染色和免疫荧光染色结果显示被红色荧光标记的iPS细胞的多能性依然存在。结论：成功建立了稳定表达红色荧光蛋白的猪naive-like iPS细胞系。     

Amaxa Nucleofector~（TM）核转染仪转染白血病细胞株L1210

慢性淋巴细胞白血病细胞株L1210是广泛运用于白血病发病机制以及化疗药物研究的细胞模型,但该细胞株与其它悬浮细胞株一样,存在着转染效率低的难题。本研究旨在探讨如何提高L1210细胞株的转染效率。应用报告基因pEGFP并通过Amaxa NucleofectorTM核转染仪的几种转染预设模式转染悬浮L1210细胞,与脂质体Lipofectamine 2000转染进行对比,在荧光倒置显微镜下观察、使用流式细胞术检测转染效率,用台盼蓝排斥实验比较存活率。结果表明：使用核转染仪进行转染在L1210细胞中获得了很高的转染效率,且在一样细胞密度（2×106/ml）和质粒量（10μg）条件下,在24小时后进行比较,核转染仪预设模式A-20转染效率达（61.6%）,明显高于其它模式（S-18、T-20）,存活率可达50.5%;脂质体转染24小时细胞存活率为88%,但转染效率极低（〈1%）。结论：核转染仪转染L1210的效率明显高于脂质体转染方案,其转染效率最高可达61.6%,存活率可达50.5%,此结果可满足科研工作需求。     

pDsRed1-N1基因核转染兔原代骨髓基质细胞的实验研究

目的探讨以最近发展起米的核转染技术直接将编码红色荧光蛋白DNA质粒转染到兔原代骨髓基质细胞细胞核内进行基因修饰的可行性。方法从兔股骨抽取骨髓，密度梯度离心法获取原代骨髓基质细胞。以Nucleofectorw^TM技术转染pDsRed1—N1（DsRed组），以同期培养未转染的细胞作为对照组。测定细胞的活力、贴壁率、生长曲线以及转染的效率。结果在转染后48h成功发现DsRed的表达。两组细胞具有相似的形态学变化、贴壁率以及生长曲线。DsRed的表达逐渐增强，至第10天达到最高峰（54．2％），观察1个月未发现表达减弱。结论pDsRed1-N1基因核转染对兔原代骨髓基质细胞的体外增殖无明显影响；DsRed可以作为兔骨髓基质细胞有效的基因表达标记；Nucleofector^TM技术是一种简易而高效的转染兔原代骨髓基质细胞的方法。     

Potential of nucleofected human MSCs for insulin secretion

The goal of this experiment was to generate insulin-producing human mesenchymal stem cells (hMSCs) as a therapeutic source for type I diabetes mellitus, which is caused by insulin deficiency due to the destruction of islet β cells. In various trials for the treatment of type I diabetes, cell-based therapy using adult stem cells is considered to be one of the most useful candidates for the treatment. In this experiment, a non-viral method called nucleofection was used to transfect hMSCs with pEGFP-C2 and furin-cleavable human preproinsulin gene (hPPI) to produce insulin-secreting cells as surrogate β cells. Transfection efficiency was determined using flow cytometry analysis. Expression and production of insulin were tested using RT-PCR and ELISA. The expression, production and maturation of insulin from the genetically engineered hMSCs showed an increase when compared with a non-transfected control group. Insulin expression from hMSCs using nucleofection in this study has shown the potential for type I diabetes therapy. For further study, an evaluation for in vivo experiments and clinical applications must be supplemented.     

Nucleofection: a new, highly efficient transfection method for primary human keratinocytes*

Transfection is an essential tool for numerous in vitro applications including studies of gene expression, promoter analysis, and intracellular signaling pathways and also for therapeutic strategies such as tissue engineering and gene therapy. However, transfection of primary cells including keratinocytes with common methods such as calcium phosphate, DEAE-dextran, liposome-mediated transfer, electroporation or viral vectors is problematic because of low transfection efficiency and the induction of terminal differentiation. Here we analyzed the use of nucleofection, a new, electroporation-based transfection method that enables the DNA to enter directly the nucleus, for the transfection of keratinocytes. Several different conditions were tested and optimized, resulting in a final transfection efficiency of 56% in primary human epidermal keratinocytes. This efficiency is superior to all non-viral transfection methods reported so far. The number of non-viable keratinocytes after nucleofection was low, varying between 14 and 16%. In contrast to other transfection protocols, nucleofection did not induce terminal differentiation in the transfected keratinocytes. In addition, nucleofection is a fast method, because the results can be analyzed within 7 h. In summary, nucleofection is a fast, easy and highly effective alternative for the transfection of primary human keratinocytes, which offers new opportunities for various research applications.     

Nucleofection is a highly effective gene transfer technique for human melanoma cell lines

Abstract:  Despite the increasing use of gene transfer strategies in the study of cellular and molecular biology, melanoma cells have remained difficult to transfect in a safe, efficient, and reproducible manner. In the present study, we report the successful use of nucleofector technology to transfect human melanoma cell lines. This technology uses an empirically derived combination of cell line-specific solutions and nucleofector programmes to electroporate nucleic acid substrates directly into the cell nucleus. Using a colorimetric β-galactosidase assay, we optimized nucleofection parameters for 13 melanoma cell lines, leading to maximum transfection efficiency and cell survival. The combinations of cell solutions NHEM or T and nucleofector programmes A-24 or U-20 produced the best results. We compared nucleofection with two commercially available lipid-based gene transfer systems, effectene and lipofectamine 2000 using a green fluorescent protein reporter vector. Nucleofection demonstrated a 3- to 40-fold improvement in transfection efficiency when compared with the lipid-based counterparts. Nucleofection was also superior in transfecting small-interfering RNA (siRNA) as determined by Western blot analysis. Lastly, we applied nucleofection to the simultaneous transfection of a p53-dependent luciferase plasmid and p53-siRNA. Experiments using dual transfection showed knockdown of p53 expression and silencing of the reporter plasmid. In conclusion, nucleofection is highly effective for the transfer of nucleic acid substrates, singly or in combination, into human melanoma cell lines.