蓝光诱导体外培养的人视网膜色素上皮细胞凋亡

目的 观察蓝光光照对体外培养的人视网膜色素上皮（RPE）细胞凋亡的影响。 方法 用蓝光照射体外培养的人RPE细胞，分为3组，A组：不同光照强度；B组：同一光照强度，不同光照时间；C组：同一光照强度和光照时间，不同细胞培养终止时间。利用末端脱氧核酸转移酶介导的原位缺口末端标记（TUNEL）、荧光素标记的连接素V/碘化吡啶（Annexin V-FITC/PI）双染流式细胞检测、透射电子显微镜等手段观察细胞凋亡。 结果 TUNEL染色阳性细胞的体积缩小变圆，细胞核浓缩，边聚成新月形或帽状，细胞核碎裂成数个，细胞膜出胞。透射电子显微镜观察发现细胞内线粒体肿胀，线粒体内膜嵴消失；粗面内质网扩张；溶酶体增加，内含代谢产物。A组低于一定阈值［（500±100）lx］的蓝光光照对RPE细胞损伤较轻，细胞凋亡及坏死随光照强度的增强而增加；B组随着光照时间延长，RPE细胞凋亡数量没有增加，而细胞坏死逐渐增加；C组光照后6、12h，损伤以细胞凋亡为主，但随着光照时间延长，凋亡继发坏死细胞和坏死细胞明显增加。 结论 蓝光照射可引起体外培养的人RPE细胞损伤，损伤形式有凋亡、凋亡继发坏死及坏死；损伤程度呈光照强度和光照时间依赖性。 (中华眼底病杂志, 2005, 21: 384-387)

Blue-light-induced apoptosis of cultured human retinal pigment epithelial cells in vitro

Objective To observe the effect of blue light on apoptosis of cultured human retinal pigment epithelial (RPE) cells in vitro. Methods Human RPE cells were exposed to blue light, and the cells were divided into 3 groups: group A, with various intensity of illumination; group B: with same intensity but different time of illumination; group C: with same intensity and time of illumination but different finish time of the culture. The apoptosis of RPE cells was observed by TdT-dUTP terminal nick-end labeling (TUNEL) and annexin V-fluoresein isothiocyanate (FITC)/propidium iodide (PI) flow cytometry, and transmission electron microscopy. Results The positive cells stained by TUNEL shrinked and turned round, whose nuclei concentrated and congregated like the crescent or hat. Cracked nuclei and membrane bleb were found. Swollen mitochondrial, disappeared inner limiting membrane of mitochondria, and dilation of the rough endoplasmic reticulum with metabolite were observed by transmission electronmicroscopy. In group A, mild damage of RPE cells was found when the threshold value of the intensity of illumination was less than（500±100）lx, and the apoptosis and necrosis of RPE cells aggravated as the intensity of illumination increased; in group B, as the time of illumination extended, the number of apoptotic RPE cells didn′t increase while the necrosis increased; in group C, 6 and 12 hours after illumination, apoptosis of cells was the main injury, while apoptosis with necrosis was found and necrotic cells increased as the time of illumination was prolonged. Conclusions Illumination with blue light may cause damages of human RPE cells in vitro, with the modalities of apoptosis, apoptotic necrosis and necrosis. The extent of injury is dependent on intensity and duration of the illumination. (Chin J Ocul Fundus Dis, 2005, 21: 384-387)