豚鼠形觉剥夺性近视眼巩膜基质金属蛋白酶-2表达的实验研究

The expression of MMP-2 in sclera of form deprived eyes in guinea pigs

目的观察形觉剥夺性近视眼后极部巩膜组织细胞外基质的改变以及基质金属蛋白酶-2(matrix melallopro-teniases,MMP-2)表达的变化,以揭示其与形觉剥夺性近视眼后极部巩膜组织改变的关系。方法采用形觉剥夺方法建立豚鼠的近视动物模型。分别测量后极部巩膜组织厚度和干重,应用免疫组化技术研究MMP-2在形觉剥夺8周后的豚鼠处理眼与对照眼后极部巩膜中表达的差异。结果形觉剥夺后处理眼较对侧眼及正常对照眼有明显近视形成(P<0.001),形成的近视度数分别为(-8.20±1.21)DS和(-7.00±1.03)DS;剥夺后后极部巩膜厚度明显变薄(P<0.01),剥夺前后厚度差为(13.8±8.2)μm;干重减轻(P<0.05),剥夺前后干重差为(0.13±0.07)mg。MMP-2在形觉剥夺后的豚鼠处理眼、对侧眼及正常对照眼后极部巩膜的表达定位于成纤维细胞胞浆和细胞外基质中。处理眼后极部巩膜中MMP-2表达量明显高于对侧眼及正常对照眼(P<0.001)。结论形觉剥夺眼后极部巩膜组织细胞外基质有显著降解趋势,同时MMP-2表达升高。MMP-2可能参与了形觉剥夺性近视发生过程中巩膜的重塑。

Objective To investigate changes in matrix metalloproteinase-2 （MMP-2） in selera of guinea pig eyes with form deprivation myopia. Methods Form deprivation was establisbed rnonoeularly in 16 guinea pigs （18 days of age） for 8 weeks. Six guinea pigs with age matching that of the experimental group were used as normal control, ocular measurements including refraction, axial length, thickness and dry weight of the pesterior selera were perfomaed prior to and after the form deprivation. MMP-2 at the posterior salem was measured using immunobistochemistry after the form deprivation with the levels of expression compared among the deprived, fellow and normal control eyes. Results The deprived eyes showed myopia of （-7.00± 1.03） D in relative to the normal control eyes after 8 weeks of form deprivation. The posterior selera was significantly thinner in the deprived eyes [ the difference value was （13.8 ± 8.2）μm, P 〈 0.01]. The dry weight of the posterior sclera was smaller in the deprived eyes than both the fellow and norreal control eyes [ the difference value was （0.13 ± 0.07）mg, P 〈 0.05 ]. The level of expression in MMP-2 was higher in the deprived eyes than both the fellow and normal control eyes. Conclusion Form deprivation myopia in guinea pig eyes is associated an increasing amount of MMP-2 in the posterior scleral tissue, indicating an increased degradation of the extracelular matrices.