Gene expression profiling of vasoregression in the retina

Vasoregression is a hallmark of vascular eye diseases but the mechanisms involved are still largely unknown. We have recently characterized a rat ciliopathy model which develops primary photoreceptor degeneration and secondary vasoregression. To improve the understanding of secondary vasoregression in retinal neurodegeneration, we used microarray techniques to compare gene expression profiles in this new model before and after retinal vasoregression. Differential gene expression was validated by quantitative RT-PCR, Western blot and immunofluorescence. Of the 374 genes regulated more than twofold, the MHC class II invariant chain CD74 yielded the strongest upregulation, and was allocated to activated microglial cells close to the vessels undergoing vasoregression. Pathway clustering identified genes of the immune system, inflammatory signaling, and components of the complement cascade upregulated during vasoregression. Furthermore, macroglial cells were markedly activated. Together, our data suggest that glial cells involved in retinal immune response participate in the initiation of vasoregression in the retina. we used microarray techniques to define gene expression profiles related to vasoregression in a rat ciliopathy model. PKD-2-247 rats (TGR) and male Sprague-Dawley (SD) rats at 1 and 3 months of age were used for the analysis. SD rats served as control in this study. Three individual rat retinae (n=3) in each group were analysed.