577 nm激光微脉冲光凝对兔神经视网膜层VEGF、PEDF及TGF-β2 mRNA表达的影响及意义

目的 研究577 nm激光微脉冲光凝对兔眼神经视网膜层VEGF、PEDF及TGF-β2 mRNA表达的影响及意义。设计 动物实验研究。研究对象 健康成年青紫蓝兔14只。方法 实验兔随机分为2组：空白对照组（2只）及实验组（12只）。采用577 nm激光对实验组兔眼视网膜进行阈值下微脉冲光凝。石蜡切片HE染色观察光凝后3天（3只）视网膜组织形态学改变。实时荧光定量PCR检测光凝后3天（3只）、7天（3只）和14天（3只）时神经视网膜中VEGF、PEDF及TGF-β2的mRNA表达量。主要指标   VEGF、PEDF及TGF-β2的mRNA在不同时间点的表达量。 结果 光凝后所有实验兔视网膜均未见激光斑形成，组织学观察未见典型视网膜组织损伤。光凝后3天、7天及14天神经视网膜中VEGF、PEDF及TGF-β2的mRNA表达量与对照相比均升高。光凝后3天、7天及14天，VEGF在的表达量分别为2.1420±0.1217、2.5207±0.2568和1.5525±0.2118，其中3天与7天的表达量差异无统计学意义（P=0.099），而14天与3天和7天比较明显减少（P=0.029、0.005）。PEDF表达量分别为3.2623±0.1442、6.4050±0.1117和4.2976±0.2813，各时间点表达量差异均有统计学意义（P=0.0003、0.002、0.0002）。TGF-β2表达量分别为2.7054±0.1571、2.5747±0.0858和2.3128±0.2742，各时间点的表达量差异均无统计学意义（P=0.155）。结论 577nm激光微脉冲光凝可上调正常兔眼神经视网膜层VEGF、PEDF及TGF-β2表达，可能与其治疗黄斑水肿的机制相关。（眼科， 2017, 26： 112-116）

Studies on effects and meaning of micropulse subthreshold 577nm laser photocoagulation on mRNA expression of VEGF,PEDF and TGF-β2 in neural retina of rabbit

 Objective To investigate the effects of micropulse subthreshold 577nm laser photocoagulation on mRNA expression level of VEGF, PEDF and TGF-β2 in neural retina of rabbit. Design Experimental animal study. Participants 14 healthy adult livor blue rabbits. Methods Rabbits were randomly divided into 2 groups: blank control group (n=2) and experimental group (n=12). Micropulsed subthreshold photocoagulation was done using 577nm laser. The morphological changes of retina were observed at 3 days after photocoagulation under microscopy using HE staining of histopathological sections． The mRNA expression level of VEGF, PEDF and TGF-β2 in neural retina were analyzed by RT-PCR at 3 days, 7 days and 14 days after photocoagulation． Main Outcome Measures The mRNA expression level of VEGF, PEDF and TGF-β2 in each time point. Result There was neither visible laser lesion under ophthalmoscope nor retinal tissue damage observed by microscope observation in retina of all experimental rabbits after photocoagulation. RT-PCR results showed that the mRNA expression level of VEGF, PEDF and TGF-β2 increased after laser photocoagulation. The VEGF mRNA expression level was 2.1420±0.1217, 2.5207±0.2568 and 1.5525±0.2118 on day 3, day 7 and day 14 after photocoagulation respectively. There was no statistically significant difference between day 3 and 7 (P=0.099), while the difference between day 7 and 14 showed statistical significance (P=0.029, 0.005). The PEDF mRNA expression level was 3.2623±0.1442, 6.4050±0.1117 and 4.2976±0.2813 on day 3, 7 and 14 respectively. There was statistically significant difference between day 3, 7 and 14 (P=0.0003, 0.002, 0.0002). At the same time points, the expression level of TGF-β2 mRNA was 2.7054±0.1571, 2.5747±0.0858 and 2.3128±0.2742 respectively, with no statistically significant difference between each time point (P=0.155). Conclusion Micropulsed 577nm laser photocoagulation can upregulate the VEGF, PEDF and TGF-β2 expression in rabbit neural retina, which may be related to the mechanism of treating macular edema. (Ophthalmol CHN, 2017, 26: 112-116)