Melanopsin-expressing retinal ganglion cells are more injury-resistant in a chronic ocular hypertension model
Melanopsin-expressing retinal ganglion cells are more injury-resistant in a chronic ocular hypertension model
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DOI：
10.1167/iovs.05-1295
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发表时间：
2006-07-01
影响因子：
4.4
通讯作者：
So, Kwok-Fai
中科院分区：
文献类型：
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作者：
Li, Rachel S.;Chen, Bai-Yu;So, Kwok-Fai
目的.研究慢性高眼压诱导后表达黑视素的视网膜神经节细胞（mRGCs）的存活情况。使用氩激光光凝巩膜外静脉和角膜缘静脉，升高成年Sprague-Dawley大鼠的眼内压（IOP）。用经校准的眼压计测量IOP并监测一段时间。在处死动物前7天，将一块浸有金色荧光染料的无菌泡沫置于上级丘（SC）上，以逆行标记SC投射的视网膜神经节细胞（scRGCs）。通过自由浮动免疫组织化学在整个安装的视网膜上可视化mRGC。在平铺的视网膜上计数存活的scRGC和mRGC的数量。观察mRGCs的树突分支模式和索马体大小。在激光光凝后，在实验眼中发现IOP增加了1.7倍，scRGCs显著丢失。然而，在诱导慢性高眼压后的12周内，未观察到mRGCs及其树突的显著细胞丢失或形态学变化。虽然视网膜神经节细胞（RGC）的变性是青光眼损伤的主要问题，但研究结果表明，在诱导慢性高眼压后，mRGC不太容易死亡。这一结果表明，mRGC携带一些独特的性质，这些性质不同于RGC的其他亚群。免疫组织化学方法可用于容易地将这些mRGC与其他亚型区分开。这种方法提供了一个有用的工具来研究他们的抗损伤特性，为开发有效的青光眼神经保护治疗提供信息。
PURPOSE. To investigate the survival of melanopsin-expressing retinal ganglion cells (mRGCs) after the induction of chronic ocular hypertension.METHODS. Intraocular pressure (IOP) was elevated in adult Sprague-Dawley rats using an argon laser to photocoagulate the episcleral and limbal veins. IOP was measured with a calibrated tonometer and monitored for a period. Seven days before the animals were killed, a piece of sterile foam soaked with gold fluorescent dye was placed onto the superior colliculus (SC) to label the SC-projecting retinal ganglion cells (scRGCs) retrogradely. mRGCs were visualized by free floating immunohistochemistry on whole-mounted retinas. The number of surviving scRGCs and mRGCs were counted on flatmounted retinas. The branching pattern of dendrites and soma size of mRGCs were examined.RESULTS. An similar to 1.7-fold increase of IOP and a significant loss of scRGCs were found in experimental eyes after laser photocoagulation. However, no significant cell loss or morphologic changes on mRGCs and their dendrites after the induction of chronic ocular hypertension are noticed over a 12-week period.CONCLUSIONS. Although the degeneration of retinal ganglion cells (RGCs) is a major concern in glaucomatous damage, the findings show that mRGCs are less susceptible to death after the induction of chronic ocular hypertension. This result indicates that mRGCs carry some unique properties that are different from those of other subpopulations of RGCs. The immunohistochemistry approach can be used to distinguish easily these mRGCs from other subtypes. This method provides a useful tool to investigate their injury-resistant properties that are informative for the development of effective neuroprotective treatment for glaucoma.