Changes in retinal aquaporin-9 (AQP9) expression in glaucoma.

Bioscience reports

PubMedID: 23464865

Yang MH, Dibas A, Tyan YC. Changes in retinal aquaporin-9 (AQP9) expression in glaucoma. Biosci Rep. 2013;.
The eye contains numerous water channel proteins and the roles of aquaporins in the retina are blurred, especially under disease conditions. The purpose of this study was to investigate the expression of aquaporin-9 (AQP9) gene and proteins affected by elevated intraocular pressure (IOP) in a rat model of glaucoma induced by intravitreous injection of hypertonic saline into the episcleral veins. Expression of AQP9 was investigated by real-time PCR and Western blotting. The immunoreactive expression of AQP9, AQP4 and glial fibrillary acidic protein (GFAP) in the optic nerve of rats exposed to experimentally elevated intraocular pressure was detected by immunofluorescence microscopy. The mRNA and protein expression levels of AQP9 were up-regulated in the retina of an animal model of glaucoma. The immunoreactivities of the AQP9, AQP4 and GFAP were also detected and increased in the optic nerve region. The expression of AQP9 was up-regulated in this glaucoma model and the immunoreactivities of the AQP4 and GFAP were also detected as co-localizing with AQP9 in the optic nerve region indicating retina ganglion cells were surrounded by activated astrocytes. This may indicate that the injured neurons may rely on the astrocytes. The alterations of aquaporin expression may compensate the glaucomatous damages.