Abstract
Abstract: :
Purpose: The alpha 2-adrenergic receptor agonist Brimonidine protects the retina against various insults including ischemia, optic nerve crush, and light-induced damage. Changes in gene expression have been suggested to play a role in this protective effect. By using cDNA array technology, our goal is to identify genes that are differentially expressed after Brimonidine treatment. Methods: Rats were treated with either Brimonidine (0.1 mg/kg, i.p.) or saline, and retinas were extracted 24 hours later. Total RNA was isolated and used to generate radiolabelled cDNA probes, which were used to screen cDNA arrays (Atlas Array, Clontech, Inc). Membranes were analyzed by visual inspection and with Atlas Image software to determine relative levels of gene expression. Results: In total 2352 genes were examined by cDNA array analysis, which revealed that Brimonidine treatment both up regulates and down regulates different subsets of genes. Initial analysis suggests that genes whose products play a role in transcription, metabolism, signal transduction, apoptosis and proto-oncogenes may be influenced by Brimonidine treatment. Conclusion: cDNA array analysis has allowed us to screen a large number of genes for changes in expression, at the RNA level, in response to Brimonidine treatment. We are currently performing Northern analysis to verify gene expression patterns. These studies will help to shed light on the mechanism by which Brimonidine protects the retina.
Keywords: 417 gene/expression • 489 neuroprotection • 554 retina