Light causes damage to the retina (phototoxicity) and decreases photoreceptor responses to light. The most harmful component of visible light is the blue wavelength (400–500 nm). Different filters have been tested, but so far all of them allow passing a lot of this wavelength (70%). The aim of this work has been to prove that a filter that removes 94% of the blue component may protect the function and morphology of the retina significantly. Three experimental groups were designed. The first group was unexposed to light, the second one was exposed and the third one was exposed and protected by a blue-blocking filter. Light damage was induced in young albino mice (p30) by exposing them to white light of high intensity (5,000 lux) continuously for 7 days. Short wavelength light filters were used for light protection. The blue component was removed (94%) from the light source by our filter. Electroretinographical recordings were performed before and after light damage. Changes in retinal structure were studied using immunohistochemistry, and TUNEL labeling. Also, cells in the outer nuclear layer were counted and compared among the three different groups. Functional visual responses were significantly more conserved in protected animals (with the blue-blocking filter) than in unprotected animals. Also, retinal structure was better kept and photoreceptor survival was greater in protected animals, these differences were significant in central areas of the retina. Still, functional and morphological responses were significantly lower in protected than in unexposed groups. In conclusion, this blue-blocking filter decreases significantly photoreceptor damage after exposure to high intensity light. Actually, our eyes are exposed for a very long time to high levels of blue light (screens, artificial light LED, neons…). The potential damage caused by blue light can be palliated.

Retinal degeneration in the rd10 mouse was slowed by a single intravitreal injection of hPI-PLGA-MS. Human recombinant proinsulin elicited a rapid and effective neuroprotective effect when administered in biodegradable microspheres, which may constitute a future potentially feasible delivery method for proinsulin-based treatment of RP.

BackgroundRetinitis pigmentosa (RP) is a group of hereditary retinal neurodegenerative conditions characterized by primary dysfunction and death of photoreceptor cells, resulting in visual loss and, eventually, blindness. To date, no effective therapies have been transferred to clinic. Given the diverse genetic etiology of RP, targeting common cellular and molecular retinal alterations has emerged as a potential therapeutic strategy.MethodsUsing the Pde6brd10/rd10 mouse model of RP, we investigated the effects of daily intraperitoneal administration of VP3.15, a small-molecule heterocyclic GSK-3 inhibitor. Gene expression was analyzed by quantitative PCR and protein expression and phosphorylation by Western blot. Photoreceptor preservation was evaluated by histological analysis and visual function was assessed by electroretinography.ResultsIn rd10 retinas, increased expression of pro-inflammatory markers and reactive gliosis coincided with the early stages of retinal degeneration. Compared with wild-type controls, GSK-3β expression (mRNA and protein) remained unchanged during the retinal degeneration period. However, levels of GSK-3βSer9 and its regulator AktSer473 were increased in rd10 versus wild-type retinas. In vivo administration of VP3.15 reduced photoreceptor cell loss and preserved visual function. This neuroprotective effect was accompanied by a decrease in the expression of neuroinflammatory markers.ConclusionsThese results provide proof of concept of the therapeutic potential of VP3.15 for the treatment of retinal neurodegenerative conditions in general, and RP in particular.Electronic supplementary materialThe online version of this article (10.1186/s13024-018-0251-y) contains supplementary material, which is available to authorized users.

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Retinitis pigmentosa (RP) is an inherited retinal dystrophy that courses with progressive degeneration of retinal tissue and loss of vision. Currently, RP is an unpreventable, incurable condition. We propose glycogen synthase kinase 3 (GSK-3) inhibitors as potential leads for retinal cell neuroprotection, since the retina is also a part of the central nervous system and GSK-3 inhibitors are potent neuroprotectant agents. Using a chemical genetic approach, diverse small molecules with different potency and binding mode to GSK-3 have been used to validate and confirm GSK-3 as a pharmacological target for RP. Moreover, this medicinal chemistry approach has provided new leads for the future disease-modifying treatment of RP.