Testing the role of Glucose deprivation during secondary cone death in Retinitis Pigmentosa

点击翻译按钮获取中文摘要

PI: Claudio Punzo Project Summary The inter-neuronal relationship between rod and cone photoreceptors in human and mouse is such that rod death always leads to cone death; however, loss of cones has no effect on rods. This phenomenon plays an important role in the inherited retinal degenerative disease retinitis pigmentosa, as most disease-causing alleles identified encode for genes that are exclusively expressed in rods. Since cones are essential for human vision, it is their loss that leads to blindness. We have recently proposed that cone death is a cell autonomous event caused by reduced nutrient uptake, in particular glucose, and showed that cell autonomous activation of the kinase mammalian target of rapamycin complex 1 (mTORC1), by deletion of its negative regulator the tuberous sclerosis complex protein 1 (TSC1), significantly prolongs cone survival. Since our initial findings others have also supported the notion that secondary cone death in retinitis pigmentosa is manly caused by a shortage of glucose in cones. Our cell autonomous activation of mTORC1 in cones promoted cone survival by improving the following 3 glucose related processes: uptake, retention and metabolism. In this grant we want to test to which extent each of these 3 processes contributes to cone survival. We have identified 3 genes, through a rational analysis of our data, each representing one of these 3 processes. Here we propose to test how much each gene contributes to cone survival by rAAV mediated gene transfer to cones. We will test the cone survival effect mediated by each gene individually and in combination of two genes at the same time. To ensure that our approach is mutation independent we will carry out our experiments in two mouse models of retinitis pigmentosa. Accomplishment of the proposed research will lay the foundation for the design of a rational therapeutic approach to extend vision in humans with retinitis pigmentosa.