Cardiac-specific and ligand-inducible target gene expression in transgenic mice.
Cardiac-specific and ligand-inducible target gene expression in transgenic mice.
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转基因小鼠心脏特异性和配体诱导的靶基因表达。
DOI：
10.1016/j.yjmcc.2005.01.010
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
Wei,Lei
中科院分区：
文献类型：
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作者：
Bo,Jacqueline;Yu,Wei;Zhang,Ying-Min;Demayo,FrancescoJ;Wei,Lei
转基因在心脏中的条件性表达是探索心脏表型生理基础的有用方法。本研究描述了一种二元转基因系统的开发，其中小鼠心脏中的转基因表达可以通过施用/撤回外源性化合物来打开/关闭。我们建立了一个转基因株（αMHC-Glp 65），该株含有米非司酮（RU 486）控制的嵌合转录因子（Glp 65），该嵌合转录因子受心脏特异性α-肌球蛋白重链（αMHC）启动子调控。在RU 486存在下，在心脏中表达的Glp 65能够与含有4个拷贝的17-mer GAL 4结合位点的靶基因启动子结合，导致靶基因的配体诱导的反式激活。我们通过将转基因小鼠αMHC-Glp 65与携带人生长激素（hGH）靶基因的转基因系杂交来测试该系统。我们观察到，生长激素的表达可以诱导成人以及在双基因小鼠的胚胎心脏由RU 486。基础hGH表达非常低，在2-5月龄时以500 μg/kg体重/天的RU 486给药4天后，心脏中的诱导水平估计比基础水平高800倍以上。转基因水平在撤销RU 486后7天内恢复到基础水平。该系统可用于以时间和剂量依赖性方式控制转基因的心脏特异性表达。
Conditional transgene expression in the heart is a useful approach to explore the physiological basis of the cardiac phenotype. The present study describes the development of a binary transgenic system in which transgene expression in the mouse heart can be turned on/off by administration/withdrawal of an exogenous compound. We generated a transgenic line (αMHC-Glp 65) harboring a mifepristone (RU486)-controlled chimeric transcription factor (Glp 65) under the regulatory control of the cardiac-specific α-myosin heavy chain (αMHC) promoter. In the presence of RU486, Glp 65 expressed in the heart is able to bind to a target gene promoter containing four copies of the 17-mer GAL4 binding site, resulting in ligand-inducible transactivation of the target gene. We tested this system by crossing the transgenic mice, αMHC-Glp 65, with a transgenic line harboring human growth hormone (hGH) target gene. We observed that expression of hGH could be induced in adults as well as in the embryonic hearts of bigenic mice by RU486. The basal hGH expression was very low and the inducible level in the heart was estimated over 800-fold higher versus the basal level after 4 days of administration of RU486 at 500 μg/kg body weight per day at 2–5 months of age. The level of the transgene returned to the basal level within 7 days after withdrawal of RU486. This system can be used to control cardiac-specific expression of transgene in a time- and dose-dependent manner.