Epithelial sodium channels are upregulated during epidermal differentiation.
Epithelial sodium channels are upregulated during epidermal differentiation.
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上皮钠通道在表皮分化过程中上调。
DOI：
10.1046/j.1523-1747.1999.00742.x
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发表时间：
1999
期刊：
影响因子：
--
通讯作者：
Mauro,T
中科院分区：
文献类型：
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作者：
Oda,Y;Imanzahrai,A;Kwong,A;Komuves,L;Elias,PM;Largman,C;Mauro,T
表皮角质形成细胞的终末分化与跨膜离子流有关。以前，我们已经表明，阿米洛利，上皮钠通道的抑制剂，阻断正常人角质形成细胞的分化特异性蛋白质的合成。在这里，我们已经确定了阿米洛利敏感的人上皮钠通道的特定亚基与培养的人角质形成细胞的分化，以及表皮发育。通过北方杂交、RNA酶保护试验和逆转录-聚合酶链反应评估，编码人上皮钠通道功能性α和调节性β亚基的转录本在培养的角质形成细胞和表皮中均以与肾脏相当的水平表达。在钙诱导的角质形成细胞分化过程中，人上皮钠通道-α和-β的mRNA表达增加。而人上皮钠通道的β亚基被高浓度的钙诱导，α亚基随着培养时间的延长而增加。调节性γ亚基含量较低，但也在表皮中表达。人表皮钠通道-α和-β均分布于成人表皮的有核层，但在胎儿表皮发育的早期阶段未检测到这些通道。这种协调表达的亚基表明，上皮钠通道可能发挥了重要作用，在表皮分化和皮肤发育，大概是通过调节所需的表皮终末分化的离子转运。
Terminal differentiation of epidermal keratinocytes is linked to transmembrane ion flux. Previously, we have shown that amiloride, an inhibitor of epithelial sodium channels, blocks synthesis of differentiation-specific proteins in normal human keratinocytes. Here, we have identified the specific subunits of amiloride-sensitive human epithelial sodium channels in relation to differentiation of cultured human keratinocytes, as well as to epidermal development. As assessed by northern hybridization, RNase protection assay, and reverse transcription–polymerase chain reaction, transcripts encoding functional α and regulatory β subunits of human epithelial sodium channels were expressed both in cultured keratinocytes and in epidermis at levels comparable with the kidney. The mRNA expression of both human epithelial sodium channel-α and -β increased during calcium-induced keratinocyte differentiation. Whereas the β subunit of human epithelial sodium channel was induced by elevated concentrations of calcium, the α subunit increased with duration of culture. The regulatory γ subunit was less abundant but also expressed in epidermis. Both human epithelial sodium channel-α and -β were localized throughout the nucleated layers of human adult epidermis, but these channels were not detected in early stages of fetal epidermal development. This co-ordinated expression of subunits suggests that epithelial sodium channels may play an important part in both epidermal differentiation and skin development, presumably by modulating ion transport required for epidermal terminal differentiation.