Departments of Ophthalmology, University of Maryland at Baltimore, School of Medicine, Baltimore, Maryland 21201, USA.
Invest Ophthalmol Vis Sci. 2011 Feb 16;52(2):904-10. doi: 10.1167/iovs.10-5247.
Displaced cholinergic amacrine cell neurons comprise a significant fraction of the retinal ganglion cell (RGC) layer. Rodent anterior ischemic optic neuropathy (rAION) is an optic nerve infarct, which results in RGC loss in mice. The goal was to determine whether rAION produces changes in amacrine cell neurons.
rAION was generated in transgenic mice carrying a cyan fluorescent reporter protein (CFP) gene linked to the Thy-1 promoter, which expresses CFP in RGCs. rAION was induced with standard parameters. Retinas were examined pre-and post-induction by retinal fundus microscopy. rAION induction severity was scored by changes in retinal transparency and RGC loss. Cholinergic amacrine cells were identified via choline acetyltransferase (ChAT) immunohistochemistry. ChAT and CFP expression was evaluated in flat-mounted retinas examined by confocal microscopy and western analysis.
Moderate rAION induction levels (defined as early retention of retinal transparency and <70% RGC loss) did not alter amacrine cell numbers in the RGC layer, but changed the relative levels of ChAT expression by immunohistochemistry. No changes in total ChAT protein were seen. Severe rAION induction (defined as loss of retinal transparency and >70% RGC loss) resulted in a trend toward amacrine cell loss and decreased ChAT protein levels.
There is wide disparity in mouse rAION induction levels using standardized parameters. Moderate rAION induction levels without direct retinal compromise produces isolated RGC loss, with displaced amacrine cell changes likely due to changes in RGC-amacrine communication. Severe rAION induction results in both RGC and amacrine cell loss, possibly due to intra-retinal ischemic changes.
胆碱能无长突细胞神经元占视网膜神经节细胞（RGC）层的很大一部分。 啮齿动物前部缺血性视神经病变（rAION）是视神经梗死，导致小鼠 RGC 丧失。 目的是确定 rAION 是否会导致无长突细胞神经元发生变化。
rAION 在携带与 Thy-1 启动子连接的青色荧光报告蛋白（CFP）基因的转基因小鼠中产生，该基因在 RGC 中表达 CFP。 使用标准参数产生 rAION。 通过眼底镜检查在诱导前和诱导后检查视网膜。 通过视网膜透明度变化和 RGC 丧失来评分 rAION 诱导的严重程度。 通过胆碱乙酰转移酶（ChAT）免疫组织化学鉴定胆碱能无长突细胞。 通过共聚焦显微镜和平铺视网膜的 Western 分析评估 ChAT 和 CFP 表达。
中度 rAION 诱导水平（定义为视网膜透明度早期保留和 <70%RGC 丧失）不会改变 RGC 层中的无长突细胞数量，但通过免疫组织化学改变 ChAT 表达的相对水平。 未观察到总 ChAT 蛋白的变化。 严重的 rAION 诱导（定义为视网膜透明度丧失和 >70%RGC 丧失）导致无长突细胞丧失和 ChAT 蛋白水平降低的趋势。
使用标准化参数，鼠标 rAION 诱导水平存在很大差异。 没有直接视网膜损伤的中度 rAION 诱导水平会导致孤立的 RGC 丧失，而无长突细胞的移位变化可能是由于 RGC-无长突细胞通讯的改变所致。 严重的 rAION 诱导会导致 RGC 和无长突细胞丧失，可能是由于视网膜内缺血性变化所致。
