Functional modeling of tight junctions in intestinal cell monolayers using polyethylene glycol oligomers
Functional modeling of tight junctions in intestinal cell monolayers using polyethylene glycol oligomers
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DOI：
10.1152/ajpcell.2001.281.2.c388
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发表时间：
2001-08-01
影响因子：
5.5
通讯作者：
Warhurst, G
中科院分区：
文献类型：
--
作者：
Watson, CJ;Rowland, M;Warhurst, G
尽管在紧密连接（TJ）蛋白的表征方面取得了重大进展，但由于传统细胞旁探针的局限性，对分子变化与功能的关系知之甚少。为了解决这一问题，通过测量由质谱分析的分子半径增加（3.5-7.4埃）的24种聚乙二醇（PEG）的渗透性来分析Caco-2和T84细胞系中的细胞旁途径。当与细胞旁筛选模型相结合时，这些数据提供了在对照条件下和暴露于TJ调节剂后的途径的定量描述符。两种细胞系中的PEG概况符合涉及限制性孔（半径4.3-4.5埃）和负责较大分子的渗透性的非限制性组分的双相过程。PEG分析显示EGTA和癸酸钠（C10）的作用之间存在显著差异。EGTA处理过的细胞的限制性成分由于孔半径的增加而失去了所有的大小辨别力。癸酸钠对孔半径没有影响，但通过不同的机制增加渗透性，可能涉及功能孔的数量增加。PEG分析提供了一个有用的工具，用于探测旁细胞途径的功能调节。
Despite significant advances in the characterization of tight junction (TJ) proteins, little is known about how molecular changes relate to function due primarily to the limitations of conventional paracellular probes. To address this, the paracellular pathway in Caco-2 and T84 cell lines was profiled by measuring the permeabilities of 24 polyethylene glycols (PEG) of increasing molecular radius (3.5-7.4 Angstrom) analyzed by mass spectrometry. When combined with a paracellular sieving model, these data provided quantitative descriptors of the pathway under control conditions and after exposure to TJ modulators. PEG profiles in both cell lines conformed to a biphasic process involving a restrictive pore (radius 4.3-4.5 Angstrom) and a nonrestrictive component responsible for permeability of larger molecules. PEG profiling revealed significant differences between the effects of EGTA and sodium caprate (C10). The restrictive component of EGTA-treated cells lost all size discrimination due to an increase in pore radius. Sodium caprate had no effect on pore radius but increased permeability via a different mechanism possibly involving increased numbers of functional pores. PEG profiling provides a useful tool for probing the functional regulation of the paracellular route.