Department of Pharmacology and Toxicology, Faculty of Veterinary Science, Szent István University, István u. 2, Budapest, 1078, Hungary,
Inflammation. 2015 Apr;38(2):775-83. doi: 10.1007/s10753-014-9988-9.
The effect of oxidative stress on barrier integrity and localization of transmembrane serine proteinase 2 (TMPRSS2) were studied using porcine epithelial IPEC-J2 cells on membrane inserts. Increased paracellular permeability of FITC-dextran 4 kDa (fluorescence intensity 43,508 ± 2,391 versus 3,550 ± 759) and that of gentamicin (3.41 ± 0.06 % increase to controls) were measured parallel with the reduced transepithelial electrical resistance (23.3 ± 4.06 % decrease) of cell layers 6 h after 1 h 1 mM H2O2 treatment. The immunohistochemical localization of adherens junctional β-catenin was not affected by reactive oxygen species (ROS) up to 4 mM H2O2. Peroxide-triggered enhanced paracellular permeability of IPEC-J2 cell layer was accompanied by predominantly cytoplasmic occurrence of TMPRSS2 embedded in cell membrane under physiological conditions. These results support that ROS can influence paracellular gate opening via multifaceted mode of action without involvement of β-catenin redistribution in adherens junction. Altered distribution pattern of TMPRSS2 and relocalized transmembrane serine protease activity may contribute to weakening of epithelial barrier integrity under acute oxidative stress.
采用猪肠上皮细胞（IPEC-J2）在膜插入物上研究了氧化应激对跨膜丝氨酸蛋白酶 2（TMPRSS2）的屏障完整性和定位的影响。与对照组相比，FITC-葡聚糖 4 kDa（荧光强度 43508 ± 2391 对 3550 ± 759）和庆大霉素（3.41 ± 0.06%增加）的旁通透性增加，细胞层的跨上皮电阻（TEER）降低 23.3 ± 4.06%在 1 小时 1 mM H2O2 处理后 6 小时。直到 4 mM H2O2，活性氧（ROS）对细胞间连接β-连环蛋白的免疫组织化学定位没有影响。在生理条件下，过氧化物触发的 IPEC-J2 细胞层的增强的旁通透性伴随着 TMPRSS2 主要在细胞质中出现，嵌入在细胞膜中。这些结果支持 ROS 可以通过多种作用方式影响细胞旁门的打开，而不需要细胞间连接中β-连环蛋白的重新分布。TMPRSS2 的分布模式改变和跨膜丝氨酸蛋白酶活性的重新定位可能导致上皮屏障完整性在急性氧化应激下减弱。
