Abstract
Abstract: :
Purpose: We recently described a rat model of anterior ischemic optic neuropathy (AION). Here we describe the further gene expression analysis of the retina and optic nerve tissue extracted from the AION rat model. Methods: AION was photoembolically induced in animals using an argon laser as previously described, via a custom-designed fundus contact lens. One eye was left untreated as a control. After induction, animals were sacrificed at 1 and 3 days. Retinae were harvested and retinal tissues immediately stored at -20°C. Total RNA was isolated from retina using The Qiaprep system (Qiagen Corp; Valencia, CA) per the manufacturer's directions. PolyA+ mRNA was subsequently isolated using Oligotex (Qiagen) per the manufacturer's directions. Initial messenger RNA quality was confirmed using denaturing formaldehyde gel electrophoresis. Hybridization probes were prepared using an Enzo BioArray High Yield RNA Transcript Labeling kit per the manufacturer's instructions. Probes were hybridized to a Rat Genome U34 Set GeneChip Array (Affymetrix, Santa Clara, CA) per manufacturer's instructions. Results were analyzed using proprietary software (Affymetrix, Santa Clara, CA), and cluster analysis performed using the Genespring package. Results: Genes specific for ophthalmic and neural tissue are highly expressed in the rat retina RNA. There were significant shifts in specific genes that may be associated with AION induction. Cluster analysis has provided additional information regarding the specific categories of genes expressed. Alteration in specific gene patterns correlate in part with general retinal stress, as well as potential RGC-specific metabolic proteins that may be directly related to the retinal ganglion cell loss observed in previous studies. Conclusions: Analysis of the rat AION model continue to provide insight into the pathological basis of AION. We have shown that eye-specific and neuro-specific genes are highly expressed in the rat AION model when compared to controls and that the expression of these genes may be correlated with retinal ganglion cell loss. The expression of individual genes are being verified using additional techniques such as Northern analysis and rtPCR. The protein products of the identified genes may be potentially useful as therapeutic targets to treat or prevent AION.
Keywords: gene/expression • molecular biology • neuro-ophthalmology: optic nerve