The Effect of Retinoic Acid in Changes of MMP-2 Expression and Avidity in the Posterior Sclera of Chick Eye

Objective To investigate the changes of matrix metalloproteinase 2(MMP-2) and its tissue inhibitor(TIMP-2) mRNA expression in posterior sclera of chick eye after a injection of retinoic Acid(RA).Methods 1-day-old white leghorn chicks were divided randomly and equivalently into three groups,RA was retrobulbar injected to the right eye of each chick as the experimental group,and the left eye served as self-control.NS injection as the negative control group.Meanwhile,normal age-matched animals were provided as control group.Both eyes collected after chicks were killed at 12h,24h,48h,72h after injection,and MMP-2 and TIMP-2 mRNA expression level were analyzed by single step reverse transcription-polymerase chain reaction(RT-PCR).Results Compared with normal and self-controlled groups,the level of MMP-2 mRNA expression in the posterior sclera of the experimental group was increased while that of TIMP-2 was decreased.There was significant difference between experimental groups and control groups(P0.01);As the time gone,levels of MMP-2 mRNA expression increased significantly and reached a peak at 48 hour after injection,and then decreased slightly but still maintained in a relative high level.There was significant difference between groups in different times(P0.01).However,TIMP-2 mRNA expression was just contrary to that of MMP-2.There was significant difference between normal and self-controlled groups(P0.01).Conclusion Retinoic acid can modulate the expression of MMP-2 and TIMP-2 mRNA in the posterior segment of eye directly or indirectly.RA may be an important factor to switch on the posterior sclera extracellular matrix(ECM) remodeling.