Global gene expression changes in rat retinal ganglion cells after experimental glaucoma

Goals of the study: 1. Assess the gene expression profile in rat RGC after experimental IOP elevation to elucidate the molecular mechanisms of RGC death. 2. Identify potentially novel genes and pathways that may contribute to RGC death in glaucoma. Background: Glaucoma is a neurodegenerative disease characterized by the slow, progressive degeneration of RGC. Elevated IOP is the biggest risk factor for developing glaucoma, loss of RGC and optic nerve atrophy. The pathophysiology of glaucomatous neurodegeneration is not fully understood. It is now clear that RGC die by apoptosis in glaucoma. However, what triggers the apoptosis is still unknown. So far, several gene expression studies have been performed on the retina as a whole. These studies revealed up and downregulation of many genes in response to elevated IOP and optic nerve transection. However, the retina is a complex tissue composed of neuronal, glial and vascular cell types. The RGCs only comprise 5% or less of retinal cells. The gene expression profiles from whole retina can not represent of RGC gene expression. In the current study, we sought to investigate the whole genome regulation of the RGCs in glaucoma. The study was carried out in 3 adult male Brown Norway rats with experimental glaucoma. An equal number of RGCs were captured from normal eyes and eyes with elevated IOP. Gene expression in the glaucomatous RGC was compared with that in the fellow RGC by using Affymetrix Gene chip.