title: Changes in retinal aquaporin-9 (AQP9) expression in glaucoma.
abstract: The eye contains numerous water channel proteins and the roles of AQPs (aquaporins) in the retina are blurred, especially under disease conditions. The purpose of this study was to investigate the expression of AQP9 gene and proteins affected by elevated IOP (intraocular pressure) in a rat model of glaucoma induced by intravitreous injection of hypertonic saline into the episcleral veins. The gene and protein expressions of AQP9 were investigated by real-time PCR and Western blotting. The immunoreactive expression of AQP9, AQP4 and GFAP (glial fibrillary acidic protein) in the optic nerve of rats exposed to experimentally elevated IOP 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 AQP expression may compensate the glaucomatous damage.
authors: *Department of Chemical and Materials Engineering, National Yunlin University of Science and Technology, Yunlin, Taiwan.
authors: Ming-Hui
authors: MH
authors: Yang
authors: †Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX, U.S.A.
authors: Adnan
authors: A
authors: Dibas
authors: Yu-Chang
authors: YC
authors: Tyan
mesh_terms: D000818:Animals; D051401:Aquaporin 4 / Q000096:biosynthesis; D020346:Aquaporins / Q000096:biosynthesis* / Q000235:genetics; D004195:Disease Models, Animal; D005786:Gene Expression Regulation; D005901:Glaucoma / Q000235:genetics* / Q000473:pathology; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D006801:Humans; D007429:Intraocular Pressure / Q000235:genetics*; D008297:Male; D009900:Optic Nerve / Q000378:metabolism / Q000473:pathology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D012160:Retina / Q000378:metabolism / Q000473:pathology*; D012165:Retinal Ganglion Cells / Q000378:metabolism
chemical_list: C496032:Aqp4 protein, rat; C491637:Aqp9 protein, rat; D051401:Aquaporin 4; D020346:Aquaporins; D005904:Glial Fibrillary Acidic Protein; D012333:RNA, Messenger