Laboratory of Bio-Functional Molecular Chemistry, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka 565-0871, Japan.
Biochem Biophys Res Commun. 2012 Oct 5;426(4):454-60. doi: 10.1016/j.bbrc.2012.08.083. Epub 2012 Aug 27.
Claudin-4, a member of a tetra-transmembrane protein family that comprises 27 members, is a key functional and structural component of the tight junction-seal in mucosal epithelium. Modulation of the claudin-4-barrier for drug absorption is now of research interest. Disruption of the claudin-4-seal occurs during inflammation. Therefore, claudin-4 modulators (repressors and inducers) are promising candidates for drug development. However, claudin-4 modulators have never been fully developed. Here, we attempted to design a screening system for claudin-4 modulators by using a reporter assay. We prepared a plasmid vector coding a claudin-4 promoter-driven luciferase gene and established stable reporter gene-expressing cells. We identified thiabendazole, carotene and curcumin as claudin-4 inducers, and potassium carbonate as a claudin-4 repressor by using the reporter cells. They also increased or decreased, respectively, the integrity of the tight junction-seal in Caco-2 cells. This simple reporter system will be a powerful tool for the development of claudin-4 modulators.
紧密连接是黏膜上皮细胞的重要屏障，Claudin-4 是构成紧密连接的四种跨膜蛋白家族的一员，是其功能和结构的关键组成部分。调节 Claudin-4 屏障以促进药物吸收已成为研究热点。Claudin-4 紧密连接在炎症过程中会被破坏。因此，Claudin-4 调节剂（抑制剂和激动剂）是药物开发的有前途的候选物。但是，Claudin-4 调节剂从未被完全开发。在此，我们试图通过报告基因检测建立 Claudin-4 调节剂的筛选系统。我们制备了一个 Claudin-4 启动子驱动荧光素酶基因的质粒载体，并建立了稳定表达报告基因的细胞系。我们使用报告细胞鉴定噻苯达唑、类胡萝卜素和姜黄素为 Claudin-4 的诱导剂，碳酸钾为 Claudin-4 的抑制剂。它们分别增加或减少了 Caco-2 细胞中紧密连接的完整性。该简单的报告基因系统将成为开发 Claudin-4 调节剂的有力工具。
