目的:通过检测羊膜移植对小鼠角膜碱烧伤后不同时间点基质金属蛋白酶(metalloproteinases,MMP-2,8,9)及金属蛋白酶组织抑制剂(tissue inhibitor of metalloproteinases,TIMP-1,2)的表达,探讨羊膜移植在碱烧伤病程中所起的作用。方法:将40只Balb/c小鼠随机分为实验组和对照组,采用1mol/L氢氧化钠溶液烧伤小鼠角膜;实验组小鼠右眼行羊膜移植加睑裂缝合术,对照组仅行睑裂缝合术。分别在羊膜移植后的第0,2,7,14d处死小鼠,应用Western blot检测不同时间点MMP-2,8,9及TIMP-1,2的表达,增强化学发光法(enhanced chemiluminescent,ECL)对结果进行分析。结果:对照组角膜中MMP-2,8,9在第2d出现表达,第14d达到峰值,且表达主要位于基质层及上皮下的炎性细胞中。碱烧伤后第2d TIMP-1仅微弱表达,第7d可见表达增加,第14d到达峰值。TIMP-2第2d即可见表达增加,后持续增强。实验组各时间点MMP-2,8,9表达均低于对照组(P<0.01),TIMP-1,2的表达均高于对照组(P<0.01)。结论:行羊膜移植可通过抑制MMP的表达,促进TIMP表达,从而抑制和延迟碱烧伤后角膜炎性浸润及溃疡的发生和发展,对碱烧伤后角膜的重塑起着重要作用。

AIM:To study metalloproteinases(MMP) and tissue inhibitors of metalloproteinases(TIMP) expresion in cornea of mice with alkaline burns treated with amniotic membrane transplantation (AMT),and to evaluate the effect of AMT in treatment of alkaline burns.METHODS:Forty Balb/c mice were divided into two groups (experimental group and control group) and their right eye corneas were burned with alkali(NaOH).The cornea was treated with AMT and secured with a tarsorrhaphy in experimental group,while the control group underwent tarsorrhaphy alone.At different time points(0,2,7,14 days) after AMT,mice were killed and the expressions of MMP and TIMP in cornea were measured by the Western blot technique,and the results were analyzed by enhanced chemiluminescent(ECL).RESULTS:In control group,MMP -2,8,9 expressed in the stromal cells and epithelial inflammatory cells.The level of MMP -2,8,9 elevated from the 2nd day,peaked on the 14th day.TIMP-1 expression was only slightly upregulated after alkaline burn at day 2,and expressed on the 7th day,peaked on the 14th day.TIMP-2 expression was increased at 2nd day,and significantly increased at 14th day.At the same time point,the level of MMP -2,8,9 in AMT group were greatly lower than that in control group(all P<0.01),while the level of TIMP-1,2 in AMT group were greatly higher than that in control group(all P<0.01).CONCLUSION:AMT may inhibit MMP expression and promote TIMP expression in cornea,lower rapid resolution of corneal inflammation and ulceration,and play a vital role in corneal remodeling.

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