急性视网膜缺血再灌注损伤后大鼠视网膜副凋亡和自噬的发生

目的　探讨大鼠急性视网膜缺血再灌注损伤（retinal ischemia-reperfusion injury，RIRI）后不同时间点视网膜中副凋亡及自噬的发生。方法　将30只健康成年SD雄性大鼠随机分为RIRI组及正常对照组。利用高眼压前房灌注法建立SD大鼠急性RIRI动物模型。正常对照组不做任何处理。急性RIRI后1 d、3 d、7 d、28 d各时间点取各组大鼠的视网膜组织，利用透射电子显微镜（transmission electron microscopy，TEM）检测视网膜神经节细胞（retinal ganglion cells，RGCs）副凋亡及自噬的发生；利用免疫荧光染色法检测视网膜微管相关蛋白1轻链3（microtubule associated protein 1 light chain 3，LC3）的表达。结果　急性RIRI后1 d持续至28 d，TEM可见RGCs细胞质空泡数量较正常对照组增高。急性RIRI后1 d持续至28 d，TEM可见RGCs细胞质中自噬体数量增加。正常对照组RGCs的细胞质中自噬体每50 μm²平均为0.79个，急性RIRI后7 d自噬体的平均数量达到高峰，每50 μm²平均为2.29个，与正常对照组相比差异具有统计学意义（P<0.05）。免疫荧光法检测发现，与正常对照组相比，急性RIRI后1 d开始，RGCs的细胞质中LC3表达增加，并在整个实验期间持续高表达，正常对照组RGCs层的LC3阳性细胞百分比为15.90%，急性RIRI后1 d、28 d时LC3阳性细胞百分比分别为46.95%和52.30%，与正常对照组相比差异均具有统计学意义（均为P<0.05）。结论　急性RIRI后RGCs涉及副凋亡和自噬的激活，各种类型的程序性细胞死亡可作为单一细胞死亡的形式或多种细胞死亡形式共存，参与急性RIRI视网膜损伤。

Activation of paraptosis and autophagy in rat retina following acute retinal ischemia-reperfusion injury

Objective　To investigate whether paraptosis and autophagy have an effect on acute retinal ischemia-reperfusion injury （RIRI） in an experimental rat model that recapitulates features of acute hypertensive glaucoma and to explore the possible underlying mechanisms.Methods　A total of 30 adult male Sprague-Dawley rats were randomly divided into RIRI group and control group.The acute RIRI model was induced with normal saline in the right eye of rats from the RIRI group by anterior chamber perfusion，while the rats in the control group left untreated.On day 1，day 3，day 7，day 28 after RIRI model establishment，the changes in morphology of retinal ganglion cells （RGCs） were observed by transmission electron microscopy （TEM），and the expression of microtubule-associated protein 1 light chain 3 （LC3） was measured by immumofluorescence methods.Results　When compared with the control group，the number of cytoplasmic vacuoles predominantly derived from the progressive swelling of mitochondria and/or endoplasmic reticulum （ER） in RGCs were increased in the RIRI group from day 1 to day 28 by TEM.And ultra-structural analyses showed the double-or multiple-membrane autophagosomes were markedly accumulated in the cytoplasm of RGCs following acute RIRI.The average number of autophagic vacuoles in the cytoplasm of RGCs was 0.79 per 50 μm² in the control group，and the average number of autophagosomes reached to a maximum on day 7 after acute RIRI at 2.29 per 50 μm²，which was statistically significant compared with the control group （P<0.05）.Compared to the control group，LC3 expression in the cytoplasm of RGCs was up-regulated on day 1 after acute RIRI，which sustained throughout the experimental period.The percentage of LC3 positive cells in the retinal ganglion cell layer was 15.90% in the control group，and the data was 46.95% and 52.30% on day 1 and day 28 after RIRI，respectively，both which were statistically significant compared with the normal control group （both P<0.05）.Conclusion　Both paraptosis and autophagy participate in death of RGCs after acute RIRI.Programmed cell death in different cells，either coexistence of multiple-cell death form or a single-cell death form，participates in the pathogenesis of acute RIRI.