Phenotypically silent Cre recombination within the postnatal ventricular conduction system.
Phenotypically silent Cre recombination within the postnatal ventricular conduction system.
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DOI：
10.1371/journal.pone.0174517
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发表时间：
2017
期刊：
影响因子：
3.7
通讯作者：
Munshi NV
中科院分区：
文献类型：
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作者：
Bhattacharyya S;Bhakta M;Munshi NV
心脏传导系统（CCS）由启动和维持心律的特化心肌细胞组成。对心脏内的电事件的正常序列的任何扰动都可能导致心律失常。为了了解心律是如何在分子水平上建立的，已经创建了几种在特定CCS隔室中表达Cre重组酶的转基因小鼠系。一般而言，Cre驱动系已经通过Cre同源重组到内源基因座中或通过随机插入的转基因驱动的Cre表达产生。然而，单倍不足的内源基因妥协前者的方法，而位置效应的负面影响后者。为了解决这些局限性，我们产生了心室传导系统（VCAM）的Cre驱动线，其通过靶向接触蛋白2（Cntn 2）3'非翻译区（3' UTR）来保留内源性基因表达。在这里，我们表明Cntn 23 'UTR-IRES-Cre-EGFP/+小鼠在心脏内重组floxed等位基因，并且Cre表达忠实地再现了Cntn 2在心脏内的空间分布。我们进一步证明，Cre表达出生后启动与保存天然Cntn 2蛋白。最后，我们显示Cntn 23 'UTR-IRES-Cre-EGFP/+小鼠维持正常的心脏机械和电功能。综上所述，我们的研究结果建立了一种新的VCS特异性Cre驱动线，而没有单倍不足或位置效应的不良后果。我们希望我们的新小鼠系将增加CCS特异性小鼠试剂的积累工具包，并有助于表征驱动细胞维持和功能的细胞自主分子电路。
The cardiac conduction system (CCS) is composed of specialized cardiomyocytes that initiate and maintain cardiac rhythm. Any perturbation to the normal sequence of electrical events within the heart can result in cardiac arrhythmias. To understand how cardiac rhythm is established at the molecular level, several genetically modified mouse lines expressing Cre recombinase within specific CCS compartments have been created. In general, Cre driver lines have been generated either by homologous recombination of Cre into an endogenous locus or Cre expression driven by a randomly inserted transgene. However, haploinsufficiency of the endogenous gene compromises the former approach, while position effects negatively impact the latter. To address these limitations, we generated a Cre driver line for the ventricular conduction system (VCS) that preserves endogenous gene expression by targeting the Contactin2 (Cntn2) 3’ untranslated region (3’UTR). Here we show that Cntn23’UTR-IRES-Cre-EGFP/+ mice recombine floxed alleles within the VCS and that Cre expression faithfully recapitulates the spatial distribution of Cntn2 within the heart. We further demonstrate that Cre expression initiates after birth with preservation of native Cntn2 protein. Finally, we show that Cntn23’UTR-IRES-Cre-EGFP/+ mice maintain normal cardiac mechanical and electrical function. Taken together, our results establish a novel VCS-specific Cre driver line without the adverse consequences of haploinsufficiency or position effects. We expect that our new mouse line will add to the accumulating toolkit of CCS-specific mouse reagents and aid characterization of the cell-autonomous molecular circuitry that drives VCS maintenance and function.