Faff O, Mitreiter R, Mückter H, Ben-Shaul Y, Bacher A
Lehrstuhl für Organische Chemie und Biochemie, Technische Universität München, Garching, Federal Republic of Germany.
Exp Cell Res. 1988 Jul;177(1):60-72. doi: 10.1016/0014-4827(88)90025-0.
The human colon adenocarcinoma cell line HT 29 grows virtually without tight junctions (TJ) under standard culture conditions. Earlier studies have shown that focal TJ (fasciae occludentes) can be rapidly assembled in this cell line under the influence of various proteases. Here we show that focal TJ can be induced in this cell line by a brief treatment with appropriate salt solutions. Induction by ammonium sulfate in Hanks' buffer reached a maximum value after 15 to 30 min. The amount of TJ increased with the salt concentration and reached a plateau value at a concentration of 160 mM ammonium sulfate. The amount and complexity of TJ induced by ammonium sulfate were similar to those in experiments using trypsin as inducing agent as shown by morphometric analysis. At 0 degrees C, no TJ were formed under the influence of the salt. A comparative study of TJ induction using a variety of inorganic and organic salts gave the following results. All alkali sulfates induced TJ, although with different yield. Both calcium and magnesium chloride were potent inducers. Ammonium and sodium salts encompassing a variety of anions covered a wide range from maximum induction (sulfate, citrate) to almost complete absence of induction (nitrate). Sodium chloride did not induce any TJ. It follows that the induction of TJ is a specific effect of individual ionic components of the solution as opposed to a general effect of osmolarity and ionic strength. The data suggest tentatively that antichaotropic but not chaotropic ions have the potential to trigger the formation of TJ in this experimental system.
人结肠腺癌细胞系HT 29在标准培养条件下生长时几乎没有紧密连接（TJ）。早期研究表明，在各种蛋白酶的影响下，该细胞系中可快速组装局灶性TJ（封闭小带）。在此我们表明，用适当的盐溶液短暂处理可在该细胞系中诱导局灶性TJ。在汉克斯缓冲液中用硫酸铵诱导，15至30分钟后达到最大值。TJ的数量随盐浓度增加而增加，在硫酸铵浓度为160 mM时达到平台值。形态计量分析表明，硫酸铵诱导的TJ数量和复杂性与使用胰蛋白酶作为诱导剂的实验相似。在0℃时，在盐的影响下未形成TJ。使用多种无机和有机盐进行TJ诱导的比较研究得出以下结果。所有碱金属硫酸盐均可诱导TJ，尽管产率不同。氯化钙和氯化镁都是有效的诱导剂。包含各种阴离子的铵盐和钠盐的诱导作用范围很广，从最大诱导（硫酸盐、柠檬酸盐）到几乎完全没有诱导（硝酸盐）。氯化钠未诱导出任何TJ。由此可见，TJ的诱导是溶液中单个离子成分的特定作用，而不是渗透压和离子强度的一般作用。数据初步表明，在该实验系统中，抗离液离子而非促离液离子有触发TJ形成的潜力。
