TITLE:
Claudin-1 Leads to Strong Formation of Tight Junction in Cultured Mouse Lung Microvascular Endothelial Cells
AUTHORS:
Yukari Ueda, Yasuhumi Shinmyouzu, Hikaru Nakayama, Tadatoshi Tanino, Eiko Sakurai, Eiichi Sakurai
KEYWORDS:
Mouse Lung Microvascular Endothelial Cells, Paracellular Permeability, Tight Junction, Occludin, Claudins, Zonula Occludents
JOURNAL NAME:
Pharmacology & Pharmacy,
Vol.7 No.3,
March
15,
2016
ABSTRACT: We aimed to examine paracellular barrier function in cultured mouse lung microvascular endothelial cells (LMECs). The transcellular resistance of LMEC monolayers yielded an electrical resistance of approximately 19 Ω × cm2 at days 6 - 7 in culture when the cells reached confluence, and paracellular permeable clearance of sodium fluorescein was the lowest on day 6 in culture, suggesting the formation of tight junctions (TJs) in cultured LMECs. Moreover, the expression of TJ-associated proteins, occludin, claudin-1 and -4 and zonula occludents 1 (ZO-1) was detected in LMECs at day 6 in culture. However, mRNAs of occludin, claudin-1 and -4 and ZO-1 were already expressed on day 1 after culture, and large variations were absent in the mRNA levels of occludin, claudin-4 and ZO-1 between days 1 and 7 in culture, when the level of each mRNA on day 1 in culture was used as a basal level. However, the claudin-1 mRNA level gradually increased up to approximately 7-fold on day 7 in culture over the basal level. These results indicate that the drastic increase in the mRNA expression level of claudin-1 leads to the strong formation of TJs.