Department of Ophthalmology, Georgetown University Medical Center, Washington, DC 20057, USA.
Electron and Confocal Microscopy Unit, USDA Agricultural Research Service, Beltsville, MD 20705, USA.
Dis Model Mech. 2018 Aug 16;11(9):dmm032698. doi: 10.1242/dmm.032698.
Age-related macular degeneration (AMD) is the major cause of blindness in the elderly in developed countries and its prevalence is increasing with the aging population. AMD initially affects the retinal pigment epithelium (RPE) and gradually leads to secondary photoreceptor degeneration. Recent studies have associated mitochondrial damage with AMD, and we have observed mitochondrial and autophagic dysfunction and repressed peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α; also known as Ppargc1a) in native RPE from AMD donor eyes and their respective induced pluripotent stem cell-derived RPE. To further investigate the effect of PGC-1α repression, we have established a mouse model by feeding mice with a high-fat diet (HFD) and investigated RPE and retinal health. We show that when mice expressing lower levels of are exposed to HFD, they present AMD-like abnormalities in RPE and retinal morphology and function. These abnormalities include basal laminar deposits, thickening of Bruch's membrane with drusen marker-containing deposits, RPE and photoreceptor degeneration, decreased mitochondrial activity, increased levels of reactive oxygen species, decreased autophagy dynamics/flux, and increased inflammatory response in the RPE and retina. Our study shows that is important in outer retina biology and that mice fed with HFD provide a promising model to study AMD, opening doors for novel treatment strategies.
年龄相关性黄斑变性(AMD)是发达国家老年人致盲的主要原因,随着人口老龄化,其患病率正在上升。AMD 最初影响视网膜色素上皮(RPE),并逐渐导致次级光感受器变性。最近的研究将线粒体损伤与 AMD 联系起来,我们已经观察到 AMD 供体眼中的天然 RPE 及其各自的诱导多能干细胞衍生的 RPE 中存在线粒体和自噬功能障碍以及过氧化物酶体增殖物激活受体-γ共激活因子 1α(PGC-1α;也称为 Ppargc1a)受到抑制。为了进一步研究 PGC-1α 抑制的影响,我们通过用高脂肪饮食(HFD)喂养 小鼠建立了一个小鼠模型,并研究了 RPE 和视网膜的健康状况。我们表明,当表达较低水平的 的小鼠暴露于 HFD 时,它们的 RPE 和视网膜形态和功能会出现类似 AMD 的异常。这些异常包括基底膜层状沉积物、Bruch 膜增厚伴有包含 drusen 标志物的沉积物、RPE 和光感受器变性、线粒体活性降低、活性氧水平增加、自噬动力学/通量减少以及 RPE 和视网膜中的炎症反应增加。我们的研究表明, 在外视网膜生物学中很重要,并且用 HFD 喂养的 小鼠为研究 AMD 提供了一个很有前途的模型,为新的治疗策略开辟了道路。