蓝光诱导的光感受器细胞凋亡与c-Fos蛋白的表达

The expression of c-Fos in blue lightinduced photoreceptor apoptosis in rats

目的:观察宽谱蓝光诱导Lewis大鼠视网膜光损伤后光感受器细胞的凋亡及c-Fos蛋白的表达。方法:8～10wk龄雌性Lewis大鼠24只,在循环光环境下饲养并随机分为6组。暗适应24h后,5组接受3012×115Lux的宽谱蓝光(400～500nm)照射1h,光照后予暗适应并于0,6,12,24及48h颈椎脱位法处死大鼠,摘除眼球;另1组为正常对照组,不予光照。采用透射电镜及TUNEL试剂盒检测视网膜细胞凋亡,免疫组化法检测视网膜内c-Fos蛋白的表达。结果:蓝光可特异性引起大鼠光感受器细胞凋亡和光感受器细胞内c-Fos蛋白的表达上调。光照后外核层细胞开始出现凋亡,24h达峰值,大量光感受器细胞出现核固缩并可见凋亡小体形成。c-Fos蛋白的表达在时间与空间分布上与TUNEL阳性细胞基本一致,在同一时间点,二者呈正相关(r =0.905,P <0.05)。结论:蓝光可诱导大鼠光感受器细胞凋亡,视网膜外核层中c-Fos蛋白的表达上调对视网膜蓝光损伤后光感受器细胞凋亡可能具有重要作用。

AIM: To observe the photoreceptor apoptosis and the expression of protein c-Fos after blue light exposure.· METHODS: Twenty-four female Lewis rats aged 8-10wk were divided into 6 groups. Five groups of rats exposed to blue fluorescent lights of about 3 012±115 Lux for 1h after 24h dark adaptation. Then the rats were kept in darkness for recovery and killed at 0, 6, 12, 4 and 48h after exposure. The unexposed rats were used as the controls. Apoptosis were assessed by TUNEL while c-Fos expression in retina was detected by immunohistochemistry.· RESULTS: After blue light exposure, apoptotic photoreceptor cells began to appear at 0h after exposure and increased progressively. The number of TUNEL-positive cells reached its peak at 24h after exposure and dropped at 48h. Furthermore, the c-Fos was apparently upregulated at 0h after light exposure, peaking at 24h and subsiding at 48h.· CONCLUSION: Exposure to blue light results in photoreceptor apoptosis and activation of the pro-oncogene c-fos in retinal outer nuclear layer of rats. The upregulation of c-Fos expression after blue light exposure may relate to apoptotic photoreceptor cell death.·