Abstract
Purpose: :
Penetrating ocular injury (POI) induces angiostatic activity in the vitreous humor and alters the retinal and vitreal levels of several known angiostatic proteins in the rat. The purpose of this study was to compare the gene expression profiles of POI and non-POI rat retinas, and identify POI-induced genes in order to further characterize the molecular etiology of the POI effect.
Methods: :
P14 Sprague Dawley rats received POI just posterior to the ora in the left eye. The right eye served as a non-POI control. Rats were sacrificed 24 hours later. Whole retinas from left eyes were dissected into quadrants. Retinal quadrants containing the injury site (POI quadrants) were segregated from the opposite retinal quadrant (non-POI quadrants) and pooled. Whole retinas were dissected from right eyes and pooled (non-POI control). Total RNA was isolated from the retinal tissues and processed into cRNA for hybridization to the Affymetrix Rat Exon 1.0 ST array. POI-induced genes were identified by comparison of gene expression profiles of the POI quadrants vs non-POI quadrants from left eyes, and the non-POI quadrants from left eyes vs non-POI control retinas from right eyes. Those genes that showed a 2-fold increase or decrease were entered into a data set for further analysis.
Results: :
Microarray analysis of retinal tissue revealed that the expression level of several hundred genes changed by at least 2-fold following POI administration. The biologic functions of these genes are varied and include, among others: transcription; cell cycle and growth; apoptosis and neurodegeneration; stress response and cell survival; inflammatory response; structure and tissue remodeling.
Conclusions: :
POI induces increased and decreased expression of several hundred retinal genes. Systematic confirmation of known angiostatic gene products identified by this approach supports its use as a means to elucidate the mechanism of POI-induced angiostasis. This and future studies will aid in the identification of candidate protein mediators of POI-induced angiostasis.
Keywords: retina • gene/expression • vitreous