Introduction: The breakdown of the blood-brain barrier (BBB) and the blood-nerve barrier (BNB) has been considered a key step in autoimmune diseases of the nervous systems such as neuromyelitis optica and Guillain-Barré syndrome. It had been previously thought that the BNB were leaky compared with the BBB. But recent several reports indicate that the BNB has almost same properties as a barrier system with those with BBB. Although several studies using animals to examine the difference between BBB and BNB have been published, molecular analyses using human microvascular endothelial cells derived from human BBB and BNB have not yet been reported. In this study, we performed detailed comparative analyses for the barrier properties with both of new established endothelial cell lines derived from human BBB and BNB.
Method: TY10, a conditionally immortalized human brain microvascular endothelial cell line, and FH-BNB, a conditionally immortalized human peripheral nerve microvascular endothelial cell line, were used. Firstly, we measured transendothelial electrical resistance (TEER) values of TY10 cells and FH-BNBs. In addition, Affymetrix chips, Human Transcriptome Array 2.0, were used to elucidate the difference of the expression level of the tight junction molecules on the BBB and the BNB.
Results: The TEER values of TY10 cells and FH-BNB cells were 36.3±4.0Ω.cm2 and 38.0±4.4 Ω.cm2, respectively. The expression levels of claudin-3, 4, 6, 15, 16, 17 and 19 mRNA in FH-BNBs were significantly higher than those in TY10 cells.
Conclusion: Our results indicated that barrier functions of the BNB are as tight as those of the BBB, but some differences regarding tight junction molecules participating the maintenance for tight junction were noted between these two barrier systems.