The distribution and expression of claudin-5 and occludin at the rat blood–optic nerve barrier after borneol treatment

Abstract

The purpose of this study is to investigate the distribution and expression of the tight junction membrane proteins, claudin-5 and occludin, in rat blood-optic nerve barrier after borneol treatment. Seventy-two female Wistar rats were randomly divided into the borneol gastric lavage group and the equal volume solvent gastric lavage control group. The bilateral optic nerve from the retrobulbar region to the optic chiasma was collected from the rats in the two groups before gastric lavage and at 30 min, 1, 2, 4, and 8 h after gastric lavage. The distribution and expression of claudin-5 and occludin were detected using immunofluorescence staining, Western blotting, and reverse transcription polymerase chain reaction (RT-PCR). Results showed that claudin-5 translocated from the cell membrane to the cytoplasm at 30 min following initiation of borneol treatment, and this translocation peaked at 1 h. During this period of time, a small amount of occludin also translocated from the cell membrane to the cytoplasm. Four hours after initiation of treatment, claudin-5 and occludin levels in the cytoplasm began to decrease and were restored to their normal pattern 8 h after initiation of treatment. There were no significant differences in the levels of claudin-5 or occludin before or after treatment in either group. It was concluded that claudin-5 and occludin translocate within cells of the rat blood-optic nerve barrier after borneol treatment, and this translocation was reversible. Claudin-5 may play a potential role in permeability of the blood-optic nerve barrier following borneol treatment.