Germline knockout ofprotects photoreceptors in three distinct mouse models of retinal degeneration.

Abstract

Retinitis pigmentosa (RP) is a common form of retinal dystrophy that can be caused by mutations in any one of dozens of rod photoreceptor genes. The genetic heterogeneity of RP represents a significant challenge for the development of effective therapies. Here, we present evidence for a potential gene-independent therapeutic strategy based on targeting, a transcription factor required for the normal differentiation of rod photoreceptors.knockout results in hybrid rod photoreceptors that express the full complement of rod genes, but also a subset of cone genes. We show that germline deletion ofpotently protects rods in three mechanistically diverse mouse models of retinal degeneration caused by bright-light exposure (light damage), structural deficiency (rhodopsin-deficientmice), or abnormal phototransduction (phosphodiesterase-deficientmice).knockout confers strong neuroprotective effects on rods without adverse effects on their gene expression, structure, or function. Furthermore, in all three degeneration models, prolongation of rod survival byknockout leads to lasting preservation of cone morphology and function. These findings raise the possibility that upregulation of one or more cone genes in-deficient rods may be responsible for the neuroprotective effects we observe.