TIMP-2基因转染FDM豚鼠后极部巩膜MMP-2蛋白早期动态表达

Early dynamic expression of TIMP-2 protein in posterior sclera of FDM guinea pig transfected with MMP-2 gene

目的探讨外源性基质金属蛋白酶组织抑制剂-2(tissue inhibitor of matrix metalloproteinases,TIMP)对豚鼠形觉剥夺性近视(form deprivation myopia,FDM)眼后极部巩膜基质金属蛋白酶-2(matrix metalloproteinases-2,MMP-2)蛋白表达的影响。方法单眼形觉遮盖法制备FDM豚鼠右眼模型,45只豚鼠分为TIMP-2组、空质粒组和生理盐水组,每组15只,右眼脉络膜上腔内分别注射转染TIMP-2基因的脂质体、空质粒和生理盐水,左眼暴露为自身对照;另15只豚鼠持续遮盖右眼,不作任何处理,为对照组。各组分别于注药后的第2天、第7天和第14天处死豚鼠,取眼球后极部巩膜组织,用明胶酶谱法检测MMP-2蛋白的表达。结果转染第2天、第7天和第14天TIMP-2组豚鼠后极部巩膜MMP-2酶原及活性酶的相对表达量分别为0.9012±0.0056和0.3006±0.0051、0.8876±0.0060和0.2858±0.0065、0.8915±0.0068和0.2915±0.0076,表达均降低,与自身对照组、对照组组间比较,差异均有统计学意义(均为P<0.05),而空质粒组和生理盐水组与对照组相比,转染后第2天、第7天和第14天差异均无统计学意义(均为P>0.05)。TIMP-2组豚鼠后极部巩膜MMP-2酶原及活性酶表达水平从第2天开始降低,第7天最低,第14天时略有回升,第2天与第7天、第14天之间差别均有统计学意义(均为P<0.05),第7天与第14天比较差异无统计学意义(P>0.05)。结论外源性TIMP-2基因注入FDM豚鼠后,早期即可有效抑制后极部巩膜MMP-2蛋白的表达,减缓巩膜的重塑,但随时间的延长抑制作用逐渐减弱。

Objective To investigate the effect of tissue inhibitor of matrix metalloproteinase-2（TIMP-2） on expression of matrix metalloproteinase-2（MMP-2）in the posterior sclera of the form-deprivation myopia（FDM）guinea pig.Methods The FDM guinea pig（right eye） was induced by translucent goggles.Forty-five guinea pigs were randomly assigned to three experimental groups：TIMP-2 group,empty plasmid group and saline group,15 cases in each group.Right eyes were given treatment,while lift eyes were self-control group without any treatment.Another fifteen guinea pigs were selected as control group covering the right eyes all the time.The guinea pigs were sacrificed and the posterior scleras of the eyeball were taken out at the 2nd,7th and 14th day after drug injection.The gelatin zymography method was used to measure the expression of MMP-2 protein.Results The relative expression of MMP-2 proenzyme and active enzyme were 0.901 2±0.005 6 and 0.300 6±0.005 1,0.887 6±0.006 0 and 0.285 8±0.006 5,0.891 5±0.006 8 and 0.291 5±0.007 6 after drug injection at the 2nd,7th and 14th day,the expressions were reduced in TIMP-2 group as compared with its self-control group and control group,which showed significant differences（all P0.05）,but there was no significant difference between empty plasmid group,saline group and control group（all P0.05）.The expression level of MMP-2 proenzyme and active enzyme in the posterior sclera of guinea pig in TIMP-2 group began to descend from the 2nd day after drug injection,the 7th day was the lowest,and then increased slightly at the 14th day.The expression level of MMP-2 at the 2nd day after drug injection were significant different from that at the 7th,14th day（all P0.05）,but there was no significant difference between the 7th day and the 14th day（P0.05）.Conclusion After exogenous injecting of TIMP-2 gene into FDM guinea pig,the expression of MMP-2 protein is inhibited effective at early stage,which may slow down the sclera remodeling,but this effect is weak gradually with time prolong.