The Role Of MMP-9 On Scar After Implantation Of Glaucoma Drainage Valve-alike

Background The implantation of Glaucoma drainage valve is one of the main treatments for refractory glaucoma.But there are serious complications and low success rate because of severe inflammation,immune reaction and scar in postoperation.The present study was designed to explore the effect of MMP-9 on scar after implantation of glaucoma drainage valve-alike.Objective To observe matrix metalloproteinases-9(MMP-9)expression on the different scar after implantation of different materials of glaucoma drainage valve,and to the observe scar expression on the different tissue of MMP-9 after implantation of the same materials of glaucoma drainage valve,and to explore mmp-9 effect on scar.Methods 45 New Zealand white rabbits were randomly assigned to silicone group,PMMA(Polymethyl methacrylate)group and inhibitor group with 15 rabbits in each group,which implanted silicone,PMMA coated Parylene C and silicone meanwhile injected 10 ug inhibitor of MMP-9 each time in the operation,2 days after operation and4 days after operation,respectively under the conjunctiva.In the three groups,the whole tissues around the materials from conjunctiva to sclera — removeing materials were collected at 1week,4week and 8 week respectively after surgery.The expression of inflammatory cell infiltration and fibroblast proliferation in each group were observed by HE staining.The concentration of MMP-9,TIMP-1,IL-1β and IL-10 in tissues was examinated and localized by immunohistochemistry.The expression of MMP-9,TIMP-1,IL-1β and IL-10 in tissues was detected by RT-q PCR method.Results In the first part,comparison between silicone group and PMMA group to detect MMP-9 expression on the different scar.According to HE straining result,silicone group showed significantly higher expression of inflammatory cell infiltration and fibroblast proliferation compared with PMMA group.According to immunohistochemistry results,the concentrations of MMP-9,TIMP-1,IL-1β and IL-10 were elevated in all of two groups,and were higher in silicone group than in PMMA group at each time point(P<0.05).And increased MMP-9,TIMP-1,IL-1β and IL-10 were located around the proliferated fibroblasts on surface of the sclera.According to RT-PCR results,the expression of MMP-9,TIMP-1,IL-1β and IL-10 were elevated in all of two groups,and were higher in silicone group than in PMMA group at each time point(P<0.05).The both protein and nucleic acid expression of MMP-9 and IL-10 were first raise and then fell and then increased again.In the second part,comparison between silicone group and inhibitor group to observe scar expression on the different tissue of MMP-9.According to immunohistochemistry and RT-q PCR results,the both protein and nucleic acid expression of MMP-9,TIMP-1,IL-1β and IL-10 were higher in silicone group than in inhibitor group at each time point(P<0.05).The both protein and nucleic acid expression of MMP-9 and IL-10 were first raise and then fell and then increased again.HE straining result showed that silicone group disparyed significantly higher expression of inflammatory cell infiltration and fibroblast proliferation than inhibitor group.Conclusion MMP-9 may promote the formation of scar after implantation of glaucoma drainage valve.