MMP-2和TIMP-2在激光诱导形觉剥夺的高度近视豚鼠脉络膜新生血管中的表达变化

Expression of MMP-2 and TIMP-2 in laser-induced choroidal neovascularization in guinea pigs model with form-deprivation high myopia

目的构建高度近视豚鼠脉络膜血管新生(choroidal neovascularization,CNV)模型,探讨基质金属蛋白酶(matrix metalloproteinase-2,MMP-2)和基质金属蛋白酶抑制剂(tissue inhibitor-2 of metalloproteinase,TIMP-2)在高度近视CNV形成中的作用。方法 72只2周龄三色豚鼠随机分为实验组(n=36)和对照组(n=36),实验组右眼行6周形觉剥夺诱导高度近视。两组各选取30只豚鼠右眼行532 nm激光光凝视网膜诱导CNV。于激光前和光凝后7、14、21、28、35天进行免疫组化观察光凝区域MMP-2和TIMP-2的表达,real-time PCR检测视网膜色素上皮层(retinal pigment epithelium,RPE)-脉络膜-巩膜复合物中的MMP-2和TIMP-2mRNA表达对MMP-2和TIMP-2免疫组化阳性表达的积分光密度值(integral optical desnsity,IDO)及mRNA相对表达水平进行统计学分析。结果激光光凝后实验组和对照组MMP-2和TIMP-2表达均明显上调,MMP-2于光凝后21天、TIMP-2于光凝后28天时表达高峰。激光前及光凝后各观察时间点,实验组MMP-2阳性表达和mRNA相对表达量均明显高于对照组,差异有统计学意义(P<0.05);而激光前实验组TIMP-2表达较对照组明显减少(P<0.05),光凝后各时间点两组TIMP-2表达差异无统计学意义。结论MMP-2和TIMP-2与高度近视CNV形成密切相关,MMP-2与TIMP-2表达平衡紊乱可能参与高度近视CNV的发生发展。

Objective To establish the high myopic choroidal neovascularization （CNV） in guinea pigs and to investigate the role of （matrix metalloproteinase-2, MMP-2） and tissue inhibitor-2 of metalloproteinase （TIMP-2） in high myopic CNV. Methods Seventy-two 2-week-old guinea pigs were randomized into control group （n= 36） and high myopia group （n = 36）. Right eyes were indued form deprivation high myopia for 6 weeks. Thirty guinea pigs were randomly selected in each group, and CNV were induced in the right eyes by the 532 nm laser. MMP-2 and TIMP-2 expressions were investigated by immunohistochemistry pre-laser and 7, 14, 21,28, 35 days after laser induction, respectively , while MMP-2 and TIMP-2 relative expression levels in retinal pigment epithelium （RPE）-choroid-sclera complex were detected by real-time PCR. Integral opitical density （IODs） of positive expression and mRNA relative expression levels of these factors were performed by statistical analyses. Results The expressions of MMP-2 and TIMP-2 were up-regulated in the two groups after laser photocoagulation through immunohistochemistry and real-time PCR examinations. Expression of MMP-2 peaked at 21 d and TIMP-2 at 28 d, respectively. IODs of positive expression and mRNA relative expression levels of MMP-2 were higher in high myopia group than those in control group at each inspective time point, and the differences were statistically significant （P 〈 0. 05）. TIMP-2 expression was significantly reduced in high myopia group compared with control group before laser photocoagulation （P〈0. 05） ,while there was no significant difference between the two groups at each time point after laser photocoagulation. Conclusions formation of high-myopic CNV. Balance disorders of occurrence and development of high-myopic CNV. MMP-2 and TIMP-2 were closely related to the MMP-2 and TIMP-2 might participate in the