氧诱导视网膜病模型中曲安奈德抑制新生血管生长的机制

Inhibitory mechanism of triamcinolone acetonide on oxygen-induced retinal neovascularization in mouse models

目的观察氧诱导视网膜病模型(OIR)中曲安奈德(TA)对CD14+细胞聚集及VEGF表达的干预作用,初步探讨曲安奈德抑制视网膜新生血管生长的可能机制。方法清洁级C57BL/6哺乳期小鼠36只(共36个眼球),随机将其分为四组:①正常对照组(6个眼球),6只17日龄正常小鼠先行FFA眼底造影,然后每鼠随机摘取一个眼球,行眼球石蜡切片HE染色。②单纯高氧组(6个眼球),6只17日龄OIR模型小鼠处理同单纯对照组。③TA高氧组(12个眼球),12只12日龄OIR模型小鼠随机一眼注射TA 2μL,再于17日龄后行FFA眼底造影后摘除术眼,其中6个眼球行眼球石蜡切片HE染色及视网膜CD14和VEGF免疫组化染色,另6个眼球行视网膜VEGF mRNA的real-time PCR检测。④BSS高氧(12个眼球),12只12日龄OIR模型小鼠随机一眼注射BSS 2μL,余处理同TA高氧组。用t检验两两比较各组视网膜突破内界膜的内皮细胞核数,视网膜CD14与VEGF免疫组化染色的平均吸光度值(IOD/AOI),及VEGF mRNA的相对含量值(2-ΔCt×105)。结果与正常对照组相比,高氧诱导组突破视网膜内界膜的内皮细胞核数目明显增多(t=29.62,P<0.001)。与BSS高氧组相比,TA高氧组突破视网膜内界膜的内皮细胞核数明显减少(t=19.879,P<0.001)。TA高氧组和BSS高氧组小鼠视网膜神经上皮均可见VEGF,CD14阳性染色,但BSS高氧组的VEGF、CD14含量明显高于TA高氧组(t=-2.743,P<0.05;t=-3.592,P<0.01)。并且视网膜SDF-1与CD14的蛋白含量存在正相关(r=0.662,n=12,P<0.05)。视网膜VEGF mRNA表达在BSS高氧组也明显高于TA高氧组(t=-4.754,P<0.005)。结论 TA能有效抑制小鼠视网膜新生血管形成,其机制可能是通过阻遏循环中CD14+细胞的聚集,进而减少VEGF等细胞因子表达而发挥作用。

Objective To explore the inhibitory mechanism of triamcinolone acetonide（TA） on the growth of oxygen-induced retinal neovascularization in mouse models（OIR models）.Methods Thirty six one-week-old C57BL/6J mice were randomly divided into 4 groups： normal control group,6 mice without treatment;Simple hyperoxia group,6 mice of OIR models;TA hyperoxia group,12 mouse OIR models received intravitreal injection of TA 2 μL（40 μg）;BSS hyperoxia group,12 mouse OIR models received intravitreal injection of BSS 2 μL.All the mice received fluorescein fundus angiography（FFA） test before they were killed on the17th day after birth.The eyes of normal control group and simple hyperoxia group were collected and used for HE staining.The eyes of the rest two groups were used for HE staining,immumohistochemical staining of CD14 and VEGF,and real-time PCR for detection of VEGF mRNA.T test was used to compare the number of endothelial cell nuclei that broke through the inner limiting membrane in the retina in each group,the average IOD/AOI of immunohistochemical staining of CD14 and VEGF,and the relative expression of VEGF mRNA（2–ΔCt ×105）.Results Compared with the normal control group,the number of endothelial cell nuclei that broke through the inner limiting membrane in the retina of simple hyperoxia group was significantly increased（t = 29.62,P0.001）.Compared with the BSS hyperoxia group,the number of endothelial cell nuclei in the TA hyperoxia group was significantly decreased（t = 19.879,P0.001）.Positive immunohistochemical staining for VEGF and CD14 was found in each group,and there were significant differences of VEGF and CD14 between oxygen-induction group and control group（t =-2.743,P0.05;t =-3.592,P0.01）.A strong correlation of retinal content of CD14 with the expression of SDF-1 was observed（r = 0.662,n = 12,P0.05）.There was a significant difference of the expression of VEGF mRNA between the oxygen-induction group and control group（t =-4.754,P0.005）.Conclusions Triamcinolone acetonide may inhibit the retinal neovascularization,which may be due to the reducing accumulation of CD14＋ cells and expression of VEGF.