上皮紧密连接(TJ)是由occludin、claudins、zonula occludens(ZOs)等构成的相邻细胞间连接复合体。TJ形成高选择性通透性屏障,调节溶质、免疫分子和药物的细胞旁转运,并能有效阻止肠内细菌和内毒素易位进入体循环。作为一类跨膜蛋白,claudins对TJ功能的发挥具有重要意义,其磷酸化是维持和调节细胞旁通透性的关键。本文就claudins的分子结构、组织分布、功能、调节claudins磷酸化的因素及其对胃肠屏障功能的影响作一综述。 Epithelial tight junction (TJ) is an intercellular junctional complex composed of occludins, claudins, zonula occludens (ZOs), and the like. TJ forms a highly selective barrier of permeability that mediates paracellular transport of solutes, immune molecules and drugs and effectively prevents the translocation of enteric bacteria and endotoxin into the systemic circulation. As a type of transmembrane protein, claudins play an important role in the function of TJ, and its phosphorylation is the key to maintaining and regulating paracellular permeability. This review summarizes the molecular structure, tissue distribution, function of claudins, the factors that regulate the phosphorylation of claudins and their effects on the gastrointestinal barrier function.