Developmental regulation of epithelial sodium channel subunit mRNA expression in rat colon and lung.
Developmental regulation of epithelial sodium channel subunit mRNA expression in rat colon and lung.
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大鼠结肠和肺上皮钠通道亚基 mRNA 表达的发育调节。
DOI：
10.1152/ajpgi.1998.275.6.g1227
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
McCrayJr,PB
中科院分区：
文献类型：
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作者：
Watanabe,S;Matsushita,K;Stokes,JB;McCrayJr,PB
在包括结肠、肺和肾在内的一些组织中，通过阿米洛利敏感钠离子通道的钠离子吸收在胎儿和新生儿生命的过渡中起着至关重要的作用。为了表征和对比三种上皮Na+通道复合物（ENaC）亚基的mRNA表达，我们在胎鼠（17、19、20和21天）和产后大鼠（1、3、9、15和30天）的结肠和肺中进行了RNase保护实验（RPA）和原位杂交。在结肠中，α-、β-和γ-rENaC亚基的表达量不同，但质性相似。从胎儿第19天到第30天，这三个亚单位的丰度逐渐增加。30日每个亚单位的量大约是1日的3倍。原位杂交表明，每个亚基都定位于表面上皮细胞，在隐窝中表达最少。肺部表现出完全不同的模式。与结肠相比，从胎儿第19天到第21天，肺中α-rENaC mRNA总量（通过RPA）显著增加，而β-和γ-rENaC在产前略有增加。在出生后的第9天，这三种mrna的数量都有所下降（约为第1天的75%）。第15天和第30天mRNA的含量逐渐升高，接近第1天的水平。α- renac mRNA丰度始终超过β-和γ-rENaC，且α- mRNA的表达量与β-和γ-rENaC的表达量不同。原位杂交研究表明，这三个亚基均在支气管、细支气管和肺泡上皮细胞中表达，而不在血管中表达。这些研究表明，rENaC mRNA在肺和结肠之间的表达具有显著的发育异质性，可能反映了这些器官中不同的发育调节机制。
Na+absorption via amiloride-sensitive Na+channels is of critical importance in the transition between fetal and neonatal life in several tissues, including the colon, lung, and kidney. To characterize and contrast the mRNA expression of each of the three epithelial Na+channel complex (ENaC) subunits, we conducted RNase protection assays (RPA) and in situ hybridization in colon and lung in fetal (17, 19, 20, and 21 days) and postnatal (1, 3, 9, 15, and 30 days) rats (r). In the colon the α-, β-, and γ-rENaC subunits showed quantitatively different but qualitatively similar expression. All three subunits gradually increased in abundance fromfetal day 19throughday 30of life. The amount of each subunit onday 30was approximately three times the amount atday 1. In situ hybridization showed that each subunit was localized to the surface epithelial cells with minimal expression in the crypts. The lung showed a completely different pattern. In contrast to the colon, the total amount of α-rENaC mRNA (by RPA) in the lung increased dramatically fromfetal day 19to21, whereas β- and γ-rENaC showed modest prenatal increases. The amounts of all three mRNAs fell after birth throughday 9(to about 75% of theday 1value). Ondays 15and30the amount of mRNA rose to approach the values onday 1. α-rENaC mRNA abundance always exceeded β- and γ-rENaC, and the quantitative expression was different for α- than for β- and γ-rENaC. In situ hybridization studies showed that all three subunits were expressed in epithelial cells of the bronchi, bronchioles, and alveoli and not in blood vessels. These studies show striking developmental heterogeneity in rENaC mRNA expression between lung and colon, probably reflecting different developmental regulatory mechanisms in these organs.