Contribution of Tight Junction Proteins to Ion, Macromolecule, and Water Barrier in Keratinocytes
Contribution of Tight Junction Proteins to Ion, Macromolecule, and Water Barrier in Keratinocytes
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DOI：
10.1038/jid.2012.507
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发表时间：
2013-05-01
影响因子：
6.5
通讯作者：
Brandner, Johanna M.
中科院分区：
文献类型：
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作者：
Kirschner, Nina;Rosenthal, Rita;Brandner, Johanna M.
紧密连接(TJ)在简单的上皮细胞中形成了对离子、水和大分子的选择性屏障。在角质形成细胞和表皮中，-Os被证明参与了个体屏障功能。在小鼠体内缺乏钛蛋白claudin-1(Cldn1)会导致皮肤屏障缺陷，其特征是致命的水分丢失。然而，对角质形成细胞中各种钛屏障的详细分子分析以及不同的钛蛋白的作用尚不清楚。在此，我们使用双路径阻抗谱区分培养的角质形成细胞中钛依赖的细胞旁阻力和跨细胞阻力。我们证明角质形成细胞Tis对Na+、Cl-和Ca~(2+)形成屏障，并有助于对水和不同大小的大分子的屏障作用。此外，Cldn1、Cldn4、occludin和zonula occludens-1的敲除增加了细胞对离子和大分子的通透性，表明所有这些钛蛋白都有助于屏障的形成。值得注意的是，Cldn1和Cldn4在培养的角质形成细胞中对水的钛屏障功能不是关键的。然而，Cldn1影响角质层(SC)蛋白，对SC水屏障功能至关重要，并对过敏原大小的大分子形成钛屏障至关重要。
Tight junctions (TJs) form a selective barrier for ions, water, and macromolecules in simple epithelia. In keratinocytes and epidermis, -Os were shown to be involved in individual barrier functions. The absence of the Ti protein claudin-1 (Cldn1) in mice results in a skin-barrier defect characterized by lethal water loss. However, detailed molecular analyses of the various Ti barriers in keratinocytes and the contribution of distinct Ti proteins are missing. Herein, we discriminate Ti-dependent paracellular resistance from transcellular resistance in cultured keratinocytes using the two-path impedance spectroscopy. We demonstrate that keratinocyte Tis form a barrier for Na+ Cl- and Ca2+ and contribute to barrier function for water and larger molecules of different size. In addition, knockdown of Cldn1, Cldn4, occludin, and zonula occludens-1 increased paracellular permeabilities for ions and larger molecules, demonstrating that all of these Ti proteins contribute to barrier formation. Remarkably, Cldn1 and Cldn4 are not critical for Ti barrier function for water in submerged keratinocyte cultures. However, Cldn1 influences stratum corneum (SC) proteins important for SC water barrier function, and is crucial for Ti barrier formation for allergen-sized macromolecules.