The Study On MMP-2 At Posterior Pole Sclera After Exogenous TIMP-2 Gene Transfection In Form Deprivation Myopia Guinea Pigs

Objective:To investigate the effect of exogenous TIMP-2 gene to MMP-2 at posterior pole sclera by observing the expression of MMP-2 in early myopia after exogenous TIMP-2 gene injection in form deprivation myopia guinea pigs.Methods:3-week-old tri-color guinea pigs were monocular deprived (MD) to establish form deprivation myopia (FDM) model which were confirmed by retinoscopic optometry and axial length measurement.60 FDM guinea pigs, which were selected randomly 2 weeks later, were divided into 4 groups equally, named by TIMP-2 group (the exogenous TIMP-2 gene was injected into suprachoroidal space), empty vector group (the empty plasmid was injected into suprachoroidal space), normal saline group (the normal saline was injected into suprachoroidal space) and control group. The right eyes of the TIMP-2 group, empty vector group and normal saline group were deprived again after injections while the control group without any treatment. The left eyes of TIMP-2 group were named by self-control group. The posterior pole sclera was collected at 2 days,7days and 14 days after injection. The mRNA and protein of MMP-2 were detected by RT-PCR and Western Blot, and the results between different groups as well as different time points were analyzed by statistical analysis.Results:(1) The expression of mRNA and protein of MMP-2 after exogenous TIMP-2 injection in the TIMP-2 group presented a decreasing firstly and then increasing change. There was a significant difference between 2 days and 7days time point after injection (P<0.05) while it was not between 7days and 14days time point (P>0.05). The difference was significant between TIMP-2 group, self-control group and control group at 2 days, 7days and 14 days time point(均P<0.05). However, the difference was not significant between empty vector group, normal saline group and control group at each time point(均 P>0.05). (2) The expression of mRNA of TIMP-2 after exogenous TIMP-2 injection in the TIMP-2 group presented a increasing firstly and then decreasing change. There was a significant difference between 2 days and 7days time point after injection (P<0.05) while it was not between 7days and 14days time point (P>0.05). The difference was significant between TIMP-2 group, self-control group and control group at 2 days,7days and 14 days time point(均P<0.05). However, the difference was not significant between empty vector group, normal saline group and control group at each time point(均P>0.05).Conclusion:Exogenous TIMP-2 could suppress the expression of mRNA and protein of MMP-2 significantly. The change started from the early stage of myopia, presenting a decreasing firstly and then increasing change as the time after injection prolonged.