Aquaporin expression and localization in the rabbit eye. (June 2016)

• Record Type: Journal Article
• Authors: Bogner, Barbara; Schroedl, Falk; Trost, Andrea; Kaser-Eichberger, Alexandra; Runge, Christian; Strohmaier, Clemens; Motloch, Karolina A.; Bruckner, Daniela; Hauser-Kronberger, Cornelia; Bauer, Hans Christian; Reitsamer, Herbert A.
• Is Part Of: Experimental eye research. Volume 147(2016:Jun.)
• Page Start: 20
• Page End: 30
• Publication Date: 2016-06
• Subjects: Aquaporin expression -- Eye -- Rabbit -- AQP0 -- AQP1 -- AQP2 -- AQP3 -- AQP4 -- AQP5; AB antibody -- AQP aquaporin -- bs bovine -- CTCA cell-to-fiber cell adhesion protein -- cm ciliary muscle -- CDS coding sequence -- en endothelium -- ep epithelium -- F forward -- GL ganglion cell layer -- GAPDH Glycerinaldehyd-3-phosphat-Dehydrogenase -- hu human -- INL inner nuclear layer -- IPL inner plexiform layer -- lf lens fiber -- ms mouse -- mf muscle fiber -- NFL nerve fiber layer -- NPE non-pigmented epithelium -- ONL outer nuclear layer -- OPL outer plexiform layer -- qRT-PCR quantitative reverse transcription real time polymerase chain reaction -- rb rabbit -- rt rat -- R reverse -- st stroma; Ophthalmology -- Periodicals; Eye -- Periodicals; Œil -- Périodiques; Ophthalmology; Periodicals; Electronic journals; 612.8405
• DOI: 10.1016/j.exer.2016.04.013
• Languages: English
• ISSNs: 0014-4835

Abstract

Abstract: Aquaporins (AQPs) are important for ocular homeostasis and function. While AQP expression has been investigated in ocular tissues of human, mouse, rat and dog, comprehensive data in rabbits are missing. As rabbits are frequently used model organisms in ophthalmic research, the aim of this study was to analyze mRNA expression and to localize AQPs in the rabbit eye. The results were compared with the data published for other species. In cross sections of New Zealand White rabbit eyes AQP0 to AQP5 were labeled by immunohistology and analyzed by confocal microscopy. Immunohistological findings were compared to mRNA expression levels, which were analyzed by quantitative reverse transcription real time polymerase chain reaction (qRT-PCR). The primers used were homologous against conserved regions of AQPs. In the rabbit eye, AQP0 protein expression was restricted to the lens, while AQP1 was present in the cornea, the chamber angle, the iris, the ciliary body, the retina and, to a lower extent, in optic nerve vessels. AQP3 and AQP5 showed immunopositivity in the cornea. AQP3 was also present in the conjunctiva, which could not be confirmed for AQP5. However, at a low level AQP5 was also traceable in the lens. AQP4 protein was detected in the ciliary non-pigmented epithelium (NPE), the retina, optic nerve astrocytes and extraocular muscle fibers. For most tissues the qRT-PCR data confirmed the immunohistology results and vice versa. Although species differences exist, the AQP protein expression pattern in the rabbit eye shows that, especially in the anterior section, the AQP distribution is very similar to human, mouse, rat and dog. Depending on the ocular regions investigated in rabbit, different protein and mRNA expression results were obtained. This might be caused by complex gene regulatory mechanisms, post-translational protein modifications or technical limitations. However, in conclusion the data suggest that the rabbit is a useful in-vivo model to study AQP function and the effects of direct and indirect intervention strategies to investigate e. g. mechanisms for intraocular pressure modulation or cornea transparency regulation. Highlights: mRNA expression and localization of aquaporins were investigated in the rabbit eye. The results obtained are compared to data reported for other species. The rabbit is a useful model to study AQP modulation in-vivo.