小鼠实验性视网膜脱离后光感受器细胞的凋亡

Apoptosis of photoreceptor cell in experimental model of retinal detachment in mice

目的研究小鼠实验性视网膜脱离后光感受器细胞的凋亡情况。方法将成年C57Bl/6J小鼠36只分为2组:实验组小鼠18只左眼视网膜下注射1.4%透明质酸钠造成视网膜脱离,对照组小鼠18只左眼仅作巩膜穿刺。分别于手术后1、3、7和28d摘除眼球,视网膜切片进行组织化学、免疫荧光染色,共聚焦显微镜检查。抗视锥和抗视杆细胞的抗体分别标记视锥和视杆细胞,dUTP缺口末段标记法(TUNEL)标记凋亡细胞。通过计数存活和凋亡的视锥和视杆细胞来定量光感受器细胞的凋亡和细胞丢失。结果凋亡细胞只存在于脱离部分视网膜的外核层,凋亡细胞在视网膜脱离后1d即可检测得到,3d时达到高峰,7d后陡然减少。视网膜脱离后视杆和视锥细胞的死亡呈现同样的时程。结论凋亡是视网膜脱离后光感受器细胞死亡的主要病理改变。

Objective To investigate the apoptosis of photoreceptor cells in experimental model of retinal detachment in mice. Methods Thirty-six adult C57BI/6J mice were divided into 2 groups： retinal detachment model was set up in the left eyes of 18 mice by subretinal injection with 1. 4% sodium hyaluronate in the experimental group, while the left eyes of other 18 mice underwent scleral puncture only as the control. The retinal sections were stained with histochemical and immunofluorescent staining and examined by confocal microscopy 1,3, 7 and 28 days after injection, eye enucleated, and retinal sections studied by histochemistry, immunofluorescence labeling, and confocal microscopy. Rods, cones, and apoptotic cells were labeled by antibodies of anti-rod and anti-cone cells, and terminal deoxynucleotidyl transferase dUTP nick-end labeling （TUNEL）, respectively. Photoreceptor cell apoptosis and cell loss were assessed quantitatively by counting both surviving and apoptotic rod and cone cells. Results TUNEL-positive cells were only found in the outer nuclear layer （ONL） of the detached portion of the retina, which were detected at the 1st day after the detachment. The apoptosis of the cells reached the peak at the 3rd day and decreased sharply after 7 days. Photoreceptor cell loss of both rod and cone cells followed a similar time course after retinal detachment. Conclusion Apoptosis is a major pathological degeneration of photoreceptor cell death after retinal detachment.