ube3d, a New Gene Associated with Age-Related Macular Degeneration, Induces Functional Changes in Both In Vivo and In Vitro Studies

Neovascular age-related macular degeneration (AMD) is characterized by the formation of choroidal neovascularization, which is responsible for more than 80% of cases of severe vision loss. Ubiquitin protein ligase E3D (UBE3D) gene missense has been proven to be associated with neovascular AMD in the East Asian population based on our previous study. In vivo, we explored the role of ube3d in eye development and the mechanisms underlying the development of neovascular AMD in a zebrafish model. In vitro, we investigated the function and mechanism of ube3d in oxidative damage in human retinal pigment epithelium (hRPE) cells. The ube3d gene was knocked down in zebrafish in our experiments, and rescue of ube3d morphants was also performed. We observed the zebrafish model at the molecular level and functional and morphological changes in vivo. Lentivirus-based gene transfer technology was used to overexpress/knockdown ube3d expression in hRPE cells in vitro. hRPE oxidative damage was induced by tert-butyl hydroperoxide (t-TBH). Cell proliferation and migration were assessed. Quantitative real-time PCR and western blot were used to measure the expression levels of UBE3D and CyclinB1. Abnormal eye development was found in zebrafish in this study, including small eyes, delayed retinal development, delayed retrograde melanosome transport, and reduced dark-induced hyper-locomotor activity under light-off conditions. In addition, increased angiogenesis was observed in ube3d morphants. A negative correlation between UBE3D and CyclinB1 was observed. Low UBE3D expression can promote oxidative damage and inflammatory reactions. UBE3D and autophagy have a synergetic effect on anti-oxidative damage. These findings indicate that ube3d may play an important role in the pathogenesis of AMD by affecting retinal development, oxidative damage, and autophagy.