Knockin of Cre Gene at Ins2 Locus Reveals No Cre Activity in Mouse Hypothalamic Neurons.
Knockin of Cre Gene at Ins2 Locus Reveals No Cre Activity in Mouse Hypothalamic Neurons.
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Ins2 位点 Cre 基因的敲入显示小鼠下丘脑神经元中没有 Cre 活性
DOI：
10.1038/srep20438
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发表时间：
2016-02-02
影响因子：
4.6
通讯作者：
Zhang WJ
中科院分区：
文献类型：
--
作者：
Li L;Gao L;Wang K;Ma X;Chang X;Shi JH;Zhang Y;Yin K;Liu Z;Shi Y;Xie Z;Zhang WJ
Cre驱动系的重组效率和细胞特异性对于利用Cre/LoxP方法探索胰腺β细胞生物学至关重要。一些常用的Cre系基于较短的Ins2启动子片段，在下丘脑神经元中显示重组活性；然而，这是否源于内源性Ins2启动子活性仍然存在争议。在这项研究中，我们在Ins2位点靶向插入IRES-Cre，产生了Ins2- cre敲入小鼠，并通过细胞谱系追踪研究证明Ins2基因在下丘脑中没有转录活性。Ins2-Cre驱动系在胰腺β细胞中表现出强劲的Cre表达和活性，而胰岛素表达没有明显改变。在大脑中，Cre活动主要局限于脉络膜丛，LacZ或荧光tdTomato报告者在海马或下丘脑未检测到明显的重组。此外，Ins2-Cre小鼠在体内葡萄糖刺激下表现出正常的葡萄糖耐量和胰岛素分泌。总之，该Ins2- cre驱动系可以高保真地检测体内内源性Ins2启动子活性，并且下丘脑中的负活性表明该系统是研究β细胞生物学的有前途的替代工具。
The recombination efficiency and cell specificity of Cre driver lines are critical for exploring pancreatic β cell biology with the Cre/LoxP approach. Some commonly used Cre lines are based on the short Ins2 promoter fragment and show recombination activity in hypothalamic neurons; however, whether this stems from endogenous Ins2 promoter activity remains controversial. In this study, we generated Ins2-Cre knockin mice with a targeted insertion of IRES-Cre at the Ins2 locus and demonstrated with a cell lineage tracing study that the Ins2 gene is not transcriptionally active in the hypothalamus. The Ins2-Cre driver line displayed robust Cre expression and activity in pancreatic β cells without significant alterations in insulin expression. In the brain, Cre activity was mainly restricted to the choroid plexus, without significant recombination detected in the hippocampus or hypothalamus by the LacZ or fluorescent tdTomato reporters. Furthermore, Ins2-Cre mice exhibited normal glucose tolerance and insulin secretion upon glucose stimulation in vivo. In conclusion, this Ins2-Cre driver line allowed high-fidelity detection of endogenous Ins2 promoter activity in vivo, and the negative activity in the hypothalamus demonstrated that this system is a promising alternative tool for studying β cell biology.