Burnett School of Biomedical Sciences, University of Central Florida, Orlando, FL, USA.
Mol Biotechnol. 2013 Jun;54(2):350-60. doi: 10.1007/s12033-012-9570-3.
Adrenaline and noradrenaline are important neurotransmitter hormones that mediate physiological stress responses in adult mammals, and are essential for cardiovascular function during a critical period of embryonic/fetal development. In this study, we describe a novel mouse model system for identifying and characterizing adrenergic cells. Specifically, we generated a reporter mouse strain in which a nuclear-localized enhanced green fluorescent protein gene (nEGFP) was inserted into exon 1 of the gene encoding Phenylethanolamine n-methyltransferase (Pnmt), the enzyme responsible for production of adrenaline from noradrenaline. Our analysis demonstrates that this knock-in mutation effectively marks adrenergic cells in embryonic and adult mice. We see expression of nEGFP in Pnmt-expressing cells of the adrenal medulla in adult animals. We also note that nEGFP expression recapitulates the restricted expression of Pnmt in the embryonic heart. Finally, we show that nEGFP and Pnmt expressions are each induced in parallel during the in vitro differentiation of pluripotent mouse embryonic stem cells into beating cardiomyocytes. Thus, this new mouse genetic model should be useful for the identification and functional characterization of adrenergic cells in vitro and in vivo.
肾上腺素和去甲肾上腺素是调节成年哺乳动物生理应激反应的重要神经递质激素，也是胚胎/胎儿发育关键期心血管功能所必需的。在本研究中，我们描述了一种用于鉴定和表征肾上腺素能细胞的新型小鼠模型系统。具体来说，我们构建了一种报告小鼠品系，其中将核定位增强型绿色荧光蛋白基因（nEGFP）插入到编码苯乙醇胺 N-甲基转移酶（Pnmt）的基因的外显子 1 中，该酶负责将去甲肾上腺素转化为肾上腺素。我们的分析表明，这种基因敲入突变有效地标记了胚胎和成年小鼠中的肾上腺素能细胞。我们在成年动物的肾上腺髓质中观察到 Pnmt 表达细胞中 nEGFP 的表达。我们还注意到，nEGFP 表达再现了 Pnmt 在胚胎心脏中的受限表达。最后，我们表明 nEGFP 和 Pnmt 的表达在多能性小鼠胚胎干细胞体外分化为搏动性心肌细胞的过程中是平行诱导的。因此，这种新型小鼠遗传模型应该有助于鉴定和研究体内外肾上腺素能细胞的功能特征。
