Abstract
Abstract: :
Purpose: Previous studies have demonstrated the ability of P2Y2 receptor agonist, INS37217, to enhance retinal reattachment following subretinal injection (Nour et al., 2003). Genomic analysis was performed to further define the changes in retinal gene expression patterns resulting from INS37217–mediated retinal reattachment in mice. Methods: Retinal detachment was induced in Balb/C mice by transvitreal subretinal injection of 1µl saline or INS37217 (10 µM). Retinal samples were assessed relative to mock–injected controls, which underwent corneal puncture with no subretinal delivery. Retinas were harvested from mice at 2hr, 24hr, and 7 day post–injection and total RNA was isolated using the Trizol method followed by purification using a Qiagen RNeasy column. Affymetrix Mouse Expression Set 430 GeneChips® (A&B) were hybridized with 7µg of RNA. Datasets were normalized using the "AFFY" package in the statistics software "R" and changes in gene expression patterns were validated by real–time PCR and by protein confirmation. Results: Real–time PCR confirmed differential expression of many genes including those involved in extracellular matrix remodeling, signal transduction, and novel genes whose function is currently unknown. Most transcripts demonstrated elevated expression levels upon administration of INS37217 (10 µM) and many showed peak expression levels at the 24hr timepoint. Furthermore, some genes, such as lipocalin 2 (LCN2), showed an induction exclusively following INS37217 administration. LCN2 has been previously implicated in a transferrin–independent transport/sequestration of iron, and may play a role in the regulation of signal transduction cascades and in the prevention of free radical formation leading to cell death. Conclusions: Profile analysis of gene expression under conditions of retinal detachment and subsequent reattachment can be thoroughly investigated using microarray technology. Our data indicates that delivery of INS37217 promotes expression levels of a limited set of genes. The identification of these genes and their respective functions will provide greater insight into the ability of this compound to effectively promote retinal reattachment.
Keywords: retinal detachment • gene microarray • retinal adhesion