Redox Imbalance in Retinal Degeneration Promoted by Constant Light Exposure

Congreso; XXXIV Annual Meeting SAN 2019; 2023

The overexposure to light, called Light Pollution, may be one of the many factors that can induce the interruption of retinal homeostasis, promoting the injury of this tissue by retinal cell death that results in retinal degeneration (RD). Previously, we demonstrated that constant exposure to white LED light (200 lux) affects outer nuclear layer (ONL) trigger rods and cones cell death, an increase in rhodopsin phosphorylation and significant changes in Melanopsin and Neuropsin expression and localization in the inner nuclear layer and ganglion cell layer. Therefore, to further studying the molecular pathways of RD, we have examined cellular redox state and fatty acid composition in rat retinas constantly exposed to light.We demonstrated an increase in H2O2 after 5 days; however, catalase activity did not show significant differences in all times studied. Fatty acid compositionanalysis showed that docosahexaenoic acid (DHA) decreased after 4 days. Remarkably, DHA diminution showed a positive correlation with the rise in stearic acid indicating a possible association between them.We assumed that the reduction in DHA may be affected by the oxidativestress in photoreceptors outer segment which in turn affects the stearic acid composition with consequences in membrane properties. All these miss-regulation affects the photoreceptor survival through unknown mechanisms involved. We consider that oxidative stress might be one of the pathways implicated in RD promoted by light.