Institute of Clinical Physiology, Charité, Berlin, Germany.
Acta Physiol (Oxf). 2011 Jan;201(1):133-40. doi: 10.1111/j.1748-1716.2010.02148.x.
A prerequisite of epithelial transport is a paracellular barrier function, which seals the tissue against an uncontrolled leak flux. Moreover, selective paracellular permeability has been shown to be crucial for physiological epithelial transport function. Claudins are tetraspan tight junction proteins which play a major role in paracellular ion permeability across epithelia. The multigene family consists of 24 members and several splice variants which show distinct tissue-specific expression profiles. Moreover, in diseases associated with a loss of barrier function such as forms of inflammatory bowel disease, the expression of claudins is altered. Functional characterization of single claudins revealed specific contribution to barrier properties in epithelia. This review gives an overview on the exploration of molecular structure and barrier function along the intestine and nephron, which not only share mechanisms of selective restriction of the paracellular pathway but also exhibit distinct organ-specific characteristics.
上皮细胞转运的一个前提是细胞旁屏障功能，它阻止组织不受控制的渗漏。此外，选择性细胞旁通透性对于生理上皮细胞转运功能至关重要。 Claudin 是四跨膜紧密连接蛋白，在跨上皮细胞的离子渗透性中起主要作用。该多基因家族由 24 个成员和几个剪接变体组成，它们表现出不同的组织特异性表达谱。此外，在与屏障功能丧失相关的疾病中，如某些形式的炎症性肠病，claudin 的表达发生改变。对单个 Claudin 的功能特征分析揭示了其对上皮细胞屏障特性的特定贡献。这篇综述概述了对沿肠道和肾单位的分子结构和屏障功能的探索，这不仅共享选择性限制细胞旁途径的机制，而且还表现出独特的器官特异性特征。
