Department of Anatomy, Neurobiology Laboratory, All India Institute of Medical Sciences, New Delhi, 110029, India.
Department of Anatomy, Neurobiology Laboratory, All India Institute of Medical Sciences, New Delhi, 110029, India.
Ann Anat. 2019 May;223:8-18. doi: 10.1016/j.aanat.2019.01.006. Epub 2019 Feb 1.
Oxidative stress (OS) is associated with retinal aging and age-related macular degeneration (AMD). In both cases there are reports for the presence of markers of lipid peroxidation in retinal cells. We investigated if nitrosative stress also occurs in the human retina with aging. We examined the cellular localization of nitro-tyrosine, a biomarker of protein tyrosine nitration, in human donor retina (17-91 years; N = 15) by immunohistochemistry. Immunoreactivity (IR) to nitro-tyrosine was present in ten retinas and absent in five retinas. It was predominant in photoreceptor inner segments, cell bodies and axons. In six retinas, IR was present in abnormal, swollen axons of macular and peripheral cones. In the inner retina, weak immunoreactivity was detected in the outer and inner plexiform layer. Transmission electron microscopy revealed a variable degree of microtubule disorganization, abnormal outgrowth from the swollen macular axons (as the fibers of Henle) and few dead axons. The present study adds further evidence to the presence of aberrant photoreceptor axonal changes in the human retina and that nitro-tyrosine immunoreactivity is associated with the photoreceptor cells in select human retina.
氧化应激（OS）与视网膜衰老和年龄相关性黄斑变性（AMD）有关。在这两种情况下，都有报道称视网膜细胞中存在脂质过氧化的标志物。我们研究了随着年龄的增长，人类视网膜是否也会发生硝化应激。我们通过免疫组织化学法检查了人供体视网膜（17-91 岁；N=15）中硝基酪氨酸（一种蛋白质酪氨酸硝化的生物标志物）的细胞定位。硝基酪氨酸的免疫反应（IR）在 10 个视网膜中存在，在 5 个视网膜中不存在。它主要存在于光感受器的内节、细胞体和轴突中。在 6 个视网膜中，IR 存在于黄斑和周边锥体异常肿胀的轴突中。在内层视网膜中，在外丛状层和内丛状层检测到弱的免疫反应。透射电镜显示微管排列紊乱程度不同，从肿胀的黄斑轴突（如 Henle 纤维）异常长出，并出现少数死轴突。本研究进一步证明了人类视网膜中存在异常的光感受器轴突变化，并且硝基酪氨酸免疫反应与特定人类视网膜中的光感受器细胞有关。
