This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Eukaryotic initiation factor 3

Reporter transgene assays and comparative polysome-microarray analysis reveal that the intact h subunit of Arabidopsis eIF3 contributes to efficient translation initiation on mRNA leader sequences harbouring multiple uORFs.

The purpose of the present study was to test the therapeutic efficiency and safety of compacted-DNA nanoparticle-mediated gene delivery into the subretinal space of a juvenile mouse model of retinitis pigmentosa. Nanoparticles containing the mouse opsin promoter and wild-type mouse Rds gene were injected subretinally into mice carrying a haploinsufficiency mutation in the retinal degeneration slow (rds(+ or -)) gene at postnatal day (P)5 and 22. Control mice were either injected with saline, injected with uncompacted naked plasmid DNA carrying the Rds gene, or remained untreated. Rds mRNA levels peaked at postinjection day 2 to 7 (PI-2 to PI-7) for P5 injections, stabilized at levels 2-fold higher than in uninjected controls for both P5 and P22 injections, and remained elevated at the latest time point examined (PI-120). Rod function (measured by electroretinography) showed modest but statistically significant improvement compared with controls after both P5 and P22 injections. Cone function in nanoparticle-injected eyes reached wild-type levels for both ages of injections, indicating full prevention of cone degeneration. Ultrastructural examination at PI-120 revealed significant improvement in outer segment structures in P5 nanoparticle-injected eyes, while P22 injection had a modest structural improvement. There was no evidence of macrophage activation or induction of IL-6 or TNF-alpha mRNA in P5 or P22 nanoparticle-dosed eyes at either PI-2 or PI-30. Thus, compacted-DNA nanoparticles can efficiently and safely drive gene expression in both mitotic and postmitotic photoreceptors and retard degeneration in this model. These findings, using a clinically relevant treatment paradigm, illustrate the potential for application of nanoparticle-based gene replacement therapy for treatment of human retinal degenerations.-Cai, X., Conley, S. M., Nash, Z., Fliesler, S. J., Cooper, M. J., Naash, M. I. Gene delivery to mitotic and postmitotic photoreceptors via compacted DNA nanoparticles results in improved phenotype in a mouse model of retinitis pigmentosa.

Previously we have shown that compacted DNA nanoparticles can drive high levels of transgene expression after subretinal injection in the mouse eye. Here we delivered compacted DNA nanoparticles containing a therapeutic gene to the retinas of a mouse model of retinitis pigmentosa. Nanoparticles containing the wild-type retinal degeneration slow (Rds) gene were injected into the subretinal space of rds+/− mice on postnatal day 5. Gene expression was sustained for up to four months at levels up to four times higher than in controls injected with saline or naked DNA. The nanoparticles were taken up into virtually all photoreceptors and mediated significant structural and biochemical rescue of the disease without histological or functional evidence of toxicity. Electroretinogram recordings showed that nanoparticle-mediated gene transfer restored cone function to a near-normal level in contrast to transfer of naked plasmid DNA. Rod function was also improved. These findings demonstrate that compacted DNA nanoparticles represent a viable option for development of gene-based interventions for ocular diseases and obviate major barriers commonly encountered with non-viral based therapies.

Cerium oxide nanoparticles, nanoceria, are inorganic antioxidants that have catalytic activities which mimic those of the neuroprotective enzymes superoxide dismutase and catalase. We have previously shown that nanoceria preserve retinal morphology and prevent loss of retinal function in a rat light damage model. In this study, the homozygous tubby mutant mouse, which exhibits inherited early progressive cochlear and retinal degeneration, was used as a model to test the ability of nanoceria to slow the progression of retinal degeneration. Tubby mice were injected systemically, intracardially, with 20 µl of 1mM nanoceria in saline, at postnatal day 10 and subsequently at P20 and P30 whereas saline injected and uninjected wild type (or heterozygous tubby) served as injected and uninjected controls, respectively. Assays for retinal function, morphology and signaling pathway gene expression were performed on P34 mice. Our data demonstrate that nanoceria protect the retina by decreasing Reactive Oxygen Species (ROS), up-regulating the expression of neuroprotection-associated genes; down-regulating apoptosis signaling pathways and/or up-regulating survival signaling pathways to slow photoreceptor degeneration. These data suggest that nanoceria have significant potential as global agents for therapeutic treatment of inherited retinal degeneration and most types of ocular diseases.