Li Suk-Yee, Fu Zhong-Jie, Ma Huan, Jang Wai-Chi, So Kwok-Fai, Wong David, Lo Amy C Y
Eye Institute, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China.
Invest Ophthalmol Vis Sci. 2009 Feb;50(2):836-43. doi: 10.1167/iovs.08-2310. Epub 2008 Oct 20.
Retinal ischemia/reperfusion (I/R) occurs in many ocular diseases and leads to neuronal death. Lutein, a potent antioxidant, is used to prevent severe visual loss in patients with early age-related macular degeneration (AMD), but its effect on I/R insult is unclear. The objective of the present study is to investigate the neuroprotective effect of lutein on retinal neurons after acute I/R injury.
Unilateral retinal I/R was induced by the blockade of internal carotid artery using intraluminal method in mice. Ischemia was maintained for 2 hours followed by 22 hours of reperfusion, during which either lutein or vehicle was administered. The number of viable retinal ganglion cells (RGC) was quantified. Apoptosis was investigated using TUNEL assay. Oxidative stress was elucidated using markers such as nitrotyrosine (NT) and poly(ADP-ribose) (PAR).
In vehicle-treated I/R retina, severe cell loss in ganglion cell layer, increased apoptosis as well as increased NT and nuclear PAR immunoreactivity were observed. In lutein-treated I/R retina, significantly less cell loss, decreased number of apoptotic cells, and decreased NT and nuclear PAR immunoreactivity were seen.
The neuroprotective effect of lutein was associated with reduced oxidative stress. Lutein has been hitherto used principally for protection of outer retinal elements in AMD. Our study suggests that it may also be relevant for the protection of inner retina from acute ischemic damage.
视网膜缺血/再灌注（I/R）发生于多种眼部疾病并导致神经元死亡。叶黄素是一种强效抗氧化剂，用于预防早发性年龄相关性黄斑变性（AMD）患者的严重视力丧失，但其对I/R损伤的作用尚不清楚。本研究的目的是探讨叶黄素对急性I/R损伤后视网膜神经元的神经保护作用。
采用腔内法阻断小鼠颈内动脉诱导单侧视网膜I/R。缺血持续2小时，随后再灌注22小时，在此期间给予叶黄素或赋形剂。对存活的视网膜神经节细胞（RGC）数量进行定量。使用TUNEL法研究细胞凋亡。使用硝基酪氨酸（NT）和聚（ADP-核糖）（PAR）等标志物阐明氧化应激情况。
在接受赋形剂治疗的I/R视网膜中，观察到神经节细胞层严重细胞丢失、细胞凋亡增加以及NT和PAR核免疫反应性增加。在接受叶黄素治疗的I/R视网膜中，细胞丢失明显减少，凋亡细胞数量减少，NT和PAR核免疫反应性降低。
叶黄素的神经保护作用与氧化应激减轻有关。叶黄素迄今主要用于保护AMD患者的视网膜外层成分。我们的研究表明，它可能也与保护视网膜内层免受急性缺血损伤有关。
