Yang Shu-ran, Ye Jun-jie, Long Qin
Department of Ophthalmology, PUMC Hospital, CAMS and PUMC, Beijing 100730, China.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao. 2010 Feb;32(1):55-9. doi: 10.3881/j.issn.1000-503X.2010.01.014.
To observe the expressions of the collagen , matrix metalloproteases-2 (MMP-2), and tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) in the posterior sclera of newborn guinea pigs with negative lens-defocused myopia.
Newborn guinea pigs were monocularly defocused by -10D lens. After 4 weeks of defocus, the eyes were removed to provide posterior scleral samples for detection. Expression of collagen was detected by immunohistochemistry on frozen sections of guinea pig sclera, and the protein levels of MMP-2 and TIMP-2 were evaluated by Western blot.
Immunohistochemical analysis indicated that the expressions of collagen and TIMP-2 were significantly lower and the expression of MMP-2 was significantly higher in the posterior sclera in the defocused eyes than in the contralateral eyes (all P < 0.01). However, all these indicators were not significantly different between the contralateral eyes and normal control eyes (all P > 0.05). In the defocused animals, the refraction of defocused eyes was positively correlated with the expression levels of collagen (r = 0.79, P < 0.01) and TIMP-2 (r = 0.74, P < 0.05) and was negatively correlated with the expression level of MMP-2 (r = -0.78, P < 0.01) in posterior sclera.
Alteration of extracellular matrix in the posterior sclera, probably participated by MMP-2, may exist during the development of defocus-induced myopia.
观察负透镜散焦性近视新生豚鼠后巩膜中胶原蛋白、基质金属蛋白酶-2（MMP-2）和基质金属蛋白酶组织抑制因子-2（TIMP-2）的表达情况。
用-10D透镜对新生豚鼠进行单眼散焦。散焦4周后，摘除眼球，获取后巩膜样本进行检测。通过豚鼠巩膜冰冻切片免疫组织化学法检测胶原蛋白表达，采用蛋白质印迹法评估MMP-2和TIMP-2的蛋白水平。
免疫组织化学分析表明，散焦眼后巩膜中胶原蛋白和TIMP-2的表达显著低于对侧眼，MMP-2的表达显著高于对侧眼（均P<0.01）。然而，对侧眼与正常对照眼之间所有这些指标均无显著差异（均P>0.05）。在散焦动物中，散焦眼的屈光度与后巩膜中胶原蛋白（r = 0.79，P<0.01）和TIMP-2（r = 0.74，P<0.05）的表达水平呈正相关，与MMP-2的表达水平呈负相关（r = -0.78，P<0.01）。
散焦诱导性近视发展过程中，后巩膜细胞外基质可能在MMP-2参与下发生改变。
