Bacher A, Griebl K, Mackamul S, Mitreiter R, Mückter H, Ben-Shaul Y
Lehrstuhl für Organische Chemie und Biochemie, Technische Universität München, Garching, Germany.
Exp Cell Res. 1992 May;200(1):97-104. doi: 10.1016/s0014-4827(05)80076-x.
Tight junctions (TJ) of the fascia occludens type can be induced in the human colon adenocarcinoma cell lines HT29 and Caco-2 by treatment with 320 mM cesium sulfate. This process can be completely inhibited by the protease inhibitors leupeptin and antipain. The concentration for 50% inhibition was 32 microM leupeptin and 270 microM antipain, respectively. In the polarized colon carcinoma cell line Caco-2, the spontaneous formation of histotypical TJ and the development of transepithelial electrical resistance do not occur when the cells are cultured in medium containing 400 microM leupeptin. Following the removal of leupeptin, zonula occludens type TJ and electrical resistance develop synchronously during a period of 4 h. Dihydroleupeptin, the alcohol analog of leupeptin, inhibits neither the spontaneous nor the induced assembly of TJ fibrils. Thus, the aldehyde group of leupeptin is essential for activity. These data suggest that the salt-induced as well as the spontaneous formation of TJ involve cellular proteases which are susceptible to protease inhibitors.
用320 mM硫酸铯处理人结肠腺癌细胞系HT29和Caco-2，可诱导出封闭小带类型的紧密连接（TJ）。此过程可被蛋白酶抑制剂亮抑酶肽和抑肽酶完全抑制。50%抑制浓度分别为32 μM亮抑酶肽和270 μM抑肽酶。在极化的结肠癌细胞系Caco-2中，当细胞在含有400 μM亮抑酶肽的培养基中培养时，不会自发形成典型的TJ，也不会出现跨上皮电阻的发展。去除亮抑酶肽后，封闭小带类型的TJ和电阻在4小时内同步发展。亮抑酶肽的醇类似物二氢亮抑酶肽既不抑制TJ纤维的自发组装也不抑制其诱导组装。因此，亮抑酶肽的醛基对其活性至关重要。这些数据表明，盐诱导的以及TJ的自发形成涉及对蛋白酶抑制剂敏感的细胞蛋白酶。
