Subrahmanian Sandeep M, Yerlikaya Esma I, Sunilkumar Siddharth, Toro Allyson L, McCurry Christopher M, Grillo Stephanie L, Barber Alistair J, Sundstrom Jeffrey M, Dennis Michael D
Department of Cellular and Molecular Physiology, Penn State College of Medicine, 500 University Drive, Hershey, PA, 17033, USA.
Department of Ophthalmology, Penn State College of Medicine, Hershey, PA, 17033, USA.
Geroscience. 2025 Apr;47(2):1789-1803. doi: 10.1007/s11357-024-01362-2. Epub 2024 Oct 5.
Age-related macular degeneration (AMD) is a leading cause of blindness in elderly populations, yet the molecular events that initiate the early retinal defects that lead to visual function deficits remain poorly understood. The studies here explored a role for the stress response protein Regulated in Development and DNA damage response 1 (REDD1) in the development of retinal pathology by using the oxidant stressor sodium iodate (NaIO) to model dry AMD in mice. REDD1 protein abundance was increased in the retinal pigmented epithelium (RPE) and retina of mice administered NaIO. In wild-type REDD1 mice, reactive oxygen species (ROS) levels were robustly increased in the outer retinal layers 1 day after NaIO administration, with focal areas of increased ROS seen throughout the outer retina after 7 days. In contrast with REDD1 mice, ROS levels were blunted in REDD1 mice after NaIO administration. REDD1 was also required for upregulated expression of pro-inflammatory factors in the RPE/retina and immune cell activation in the outer retina following NaIO administration. In REDD1 mice, NaIO reduced RPE65 and rhodopsin levels in the RPE and photoreceptor layers, respectively. Unlike REDD1 mice, REDD1 mice did not exhibit disrupted RPE integrity, retinal degeneration, or photoreceptor thinning. Overall, REDD1 deletion was sufficient to prevent retinal oxidative stress, RPE damage, immune cell activation, and photoreceptor loss in response to NaIO. The findings support a potential role for REDD1 in the development of retinal complications in the context of dry AMD.
年龄相关性黄斑变性(AMD)是老年人群失明的主要原因,然而引发导致视觉功能缺陷的早期视网膜缺陷的分子事件仍知之甚少。本文的研究通过使用氧化应激源碘酸钠(NaIO)在小鼠中模拟干性AMD,探讨了应激反应蛋白发育和DNA损伤反应调节蛋白1(REDD1)在视网膜病变发展中的作用。给予NaIO的小鼠视网膜色素上皮(RPE)和视网膜中REDD1蛋白丰度增加。在野生型REDD1小鼠中,给予NaIO后1天,视网膜外层的活性氧(ROS)水平显著升高,7天后整个外层视网膜可见ROS增加的局灶区域。与野生型REDD1小鼠相比,给予NaIO后,REDD1基因敲除小鼠的ROS水平降低。给予NaIO后,RPE/视网膜中促炎因子的表达上调以及外层视网膜中的免疫细胞激活也需要REDD1。在REDD1基因敲除小鼠中,NaIO分别降低了RPE层和光感受器层中RPE65和视紫红质的水平。与野生型REDD1小鼠不同,REDD1基因敲除小鼠未表现出RPE完整性破坏、视网膜变性或光感受器变薄。总体而言,REDD1基因缺失足以预防因NaIO引起的视网膜氧化应激、RPE损伤、免疫细胞激活和光感受器丢失。这些发现支持了REDD1在干性AMD背景下视网膜并发症发展中的潜在作用。