透镜诱导豚鼠近视眼巩膜基质中基质金属蛋白酶2及其组织抑制剂和生长因子的变化

目的观察透镜诱导豚鼠近视眼巩膜基质中基质金属蛋白酶2（matrix metalloproteinases 2，MMP-2）、金属蛋白酶2组织抑制剂ftissue inhibitor of metaloproteinase 2，TIMP-2）和转化生长因子B2（transforming growth factorβ2，TGF—β2）和成纤维细胞生长因子（fibroblast growth factor，bFGF）的变化．探讨透镜诱导与形觉剥夺在近视眼发生机制上的异同点。方法 11只豚鼠于诱导前后分别验光、测量眼轴长度．用-6D的透镜诱导右眼作为诱导眼，左眼作为对照眼，诱导成功后，将豚鼠处死，摘除眼球，取后极部巩膜分别进行MMP-2和TIMP-2、TGF—β2和bFGF的免疫组织化学染色．观察它们在巩膜组织成纤维细胞胞浆中表达的阳性率和阳性细胞所占面积的百分比，并与对侧眼进行比较。结果11只豚鼠诱导眼成功诱导出（-3．31±1．04）D近视，诱导眼巩膜中MMP-2的阳性率为81．8％，对照眼为45．5％，差异有显著性；TIMP-2的阳性率36．4％，对照眼为72．7％；MMP-2染色阳性细胞面积百分比为0．22±0．15．对照眼为0．06±0．08（P〈0．05）；TIMP-2为0．05±0．08，对照眼为0．13±0．10。巩膜中TGF—β2阳性率为81．8％，对照眼为36．4％（P〈0．05），bFGF的阳性率为45．5％，明显低于对照眼（63．6％）。诱导眼TGF—β2染色阳性细胞面积百分比为0．21±0．14．对照眼为0．06±0．10，差异有显著性：bFGF为0．07±0．09，对照眼为0．15±0．14。结论透镜可以成功地诱导出豚鼠近视眼．透镜诱导近视眼巩膜基质中MMP-2活性增强，TIMP-2活性降低，TGF—β2表达增加，bFGF表达减少，MMP-2和TIMP-2、TGF—β2和bFGF之间存在平衡失调．它们的改变与形觉剥夺性近视的变化相似，表明透镜诱导近视眼与形觉剥夺性近视眼在巩膜基质的改变和生长因子的变化上存在相似的机制。

The study of the role of MMP-2,TIMP-2 and growth factors in lens-induced myopia

Objective To study the role of MMP-2,TIMP-2 and growth factors in the sclera of guinea pigs with lens-induced myopia, and to investigate the differences in the mechanisms of lensinduced and form deprivation myopias. Methods Refractive error and axial length of 11 guinea pigs were measured before and after the experiment. All right eyes wore negative lenses to induce myopia and the left eyes were used as a control. After two weeks, all guinea pig eyes were enucleated and the area near the posterior pole of the sclera was observed by immunohistochemistry methods. The positive rates of MMP-2,TIMP-2,TGF-β2 and bFGF in scleral fibroblast cytoplasma were calculated and compared to the control eyes. Results Myopia was successfully induced in all 11 guinea pigs. The positive rate of MMP-2 in the myopic sclera was 81.8%, higher than that for the control eyes （45.5%）（P〈0.05）; the positive rate of TIMP-2 was 36.4%, lower than that for the control eyes （72.7%）. The positive rate of TGF-β2 was 81.8%, higher than that for the control eyes （36.4%）（P〈0.05）; the positive rate of bFGF was 45.5%, lower than that for the control eyes （63.6%）. There were similar results for the area percentage ratios. Conclusion In lens- induced experimental myopia in guinea pigs, an increase in MMP-2 and a decrease in TIMP-2, an increase in TGF-β2 and a decrease in bFGF occurred in the posterior scleral matrix, The two pairs of imbalances of MMP-2 and TIMP-2 and TGF-β2 and bFGF can cause abnormal growth of the guinea pig＇s eyeball. These changes in lens-induced myopia are the same as in form deprivation myopia. Consequently, lens-induced myopia and form deprivation myopia have some of the same regulating mechanisms for inducing changes in the sclera of myopic eyes.