携带红色荧光蛋白的RU486可诱导真核表达载体的构建及其表达

Construction and Expression in vitro of an RU486 Inducible Vector Carrying DsRed Protein

摘要:

在基因治疗中, 实现目的基因的调控表达是非常重要的。然而, 传统基因载体的无调控地持续或不适当的表达会影响治疗效果, 甚至可能带来致命的副作用。在本研究中, 我们构建了一种带有DsRed红色荧光蛋白报告基因并可经RU486诱导的真核表达载体, 并在体外评估了其调控表达作用。利用分子生物学技术, 将DsRed基因和启动子, 以及RU486系统构建成单一的质粒载体PDC-RURED, 为减少RU486调控元件和基因表达元件之间的相互干扰, 在两者之间加入1.6 kb的绝缘子。经PCR检测和限制性酶切分析及序列测定均证实了载体的正确性。在转染HEK293细胞后, 运用荧光显微镜和流式细胞技术证实了该载体的调控能力。没有RU486时, 几乎没有红色荧光蛋白的表达, 而加入诱导剂RU486后, 最高可以实现红色荧光蛋白的40余倍的表达。实验结果表明构建的可经RU486诱导的新型真核表达载体可以实现对目的基因的表达时间和表达水平的调控, 为进一步的基因调控研究和和基因治疗提供了良好的工具。

Abstract:

The regulation of a target gene expression is very important in gene therapy. However, constitutive or inappropriate expression of the genes with traditional expression system may interfere with the effect of the gene therapy, even may lead to lethal side effect. We constructed an RU486 inducible eukaryotic vector carrying DsRed protein and evaluated its regulatable effect in vitro. The single vector named PDC-RURED was constructed with molecular biological methods, which contained DsRed gene, promoter and mifepristone-inducible system. To minimize any potential interference, we spaced the two transcriptional elements with a 1.6 kb insulator. The vector was identified by different enzyme restrictions, sequencing analysis and PCR assay. We demonstrated the regulatable expression of this vector after transfection in HEK293 cells by fluorescence microscopy and flow cytometry. In the absence of RU486, no significant DsRed protein activation was observed, whereas in the presence of RU486 up to 40 fold activation of the DsRed protein was observed in cultured cells. The data show that the novel eukaryotic expression plasmid vector can be used to regulate the expression level of genes of interest in appropriate time under the control of RU486. This inducible expression vector provides a powerful tool for the research of gene regulation and gene therapy.