Expression And Significance Of Matrix Metalloproteinase-2,9 In Periapical Granuloma And Periapical Cyst.

Background Matrix metalloproteinases (MMPs) is essential to the process of degradation of extracellular matrix. Almost all the elements can degrade extracellular matrix. The expression of MMPs is very low and steady in normal tissues , but the stimulation of proinflammatory cytokines, hormones, and cell growth factor can increase the expression. MMPs can degrade extracellular matrix and basement membrane proteins in joint in chronic inflammation and bone damage. Their anomal-activity plays important roles in many diseases such as dental caries pulposis , periodontal disease,chronic disease of periapical,the infiltration and metastasis of tumors, hepatic fibrosis and joint destruction of osteoarthropathia MMP-2 and -9,called gelatinase A and gelatinase B. They hold the ability of degradating denatured collagen I ,II,III,and they can cut natural collagen IV,V,VII,XI,fibronetin and stress protein too. It was reported recently that MMP-2 can decompose native interstitial collagen I, and without TIMP-1,the compound combined by MMP-1 and MMP-9 could degrade collagen I thoroughly.They are expressed in neutrophil, odontoblast, pulp cell, epithelial cell ,macrophage, fibroblast ,osteoclast,muscle satellite cell cartilage cell and tumor cells. In addition ,gelatinases can be secreted by T cells,,and they may induce the metachoresis of T cells across membrane and promote the release of TNF as well as active TGF-β.Therefore,they play important roles in autoimmune and Inflammatory reaction.Many studies confirmed that gelatinase play important roles in normal and patho-resorption of bone.Periapical disease is caused by a variety of stimulating inflammatory, often involving the alveolar bone and adjacent apical the cementum. Its main feature is the destruction of periapical cementum and alveolar bone. Extracellular matrix of cementum and alveolar bone mainly contains organic type I. Chronic periapical disease mainly contain periapical granulomatous and radicular cysts. The investigation of the expression of MMP-2,9 in periapical granuloma and periapical cysts can not only enable us to understand the relationship between periapical disease and MMP-2,9, but also can help us study the injury and repair mechanisms of periapical disease. It will provide new ideas of the diagnosis and treatment of periapical disease.Objective Aim to investigate the expression of matrix metalloproteinase-2,9 in periapical granuloma and periapical cyst and discuss the significance .Methods Using immunohistochemistry and SDS-page -Zynograph method for the detection of 18 cases of periapical granuloma, 15 cases of periapical cyst and 10 cases of normal tissue. After electrophoresis ,electrophoresis band are scaned by computer,then collect all the data of IOD of pro-MMP-2,9 and active-MMP-2,9.Data is analyzed by SPSS 10.0 software. The comparison of means between the two groups is analyzed by independent sample t test. Using—X±S for the demonstration. Size of test :α=0.05.Results The level of MMP-2 is significantly higher in periapical granulomas and periapical cysts than those in normal tissues. (p<0.01) ,and the expression of pro-MMP-9 and active-MMP-9 in periapical granuloma group and radicular cysts group is higher than normal group too.When periapical granuloma group compared with radicular cysts group, the relative expression of MMP-2,9 has no significant difference (P> 0.05).Conclusion Gelatinase may participate the destruction of bone matrix in chronic inflammation position,thus they play important roles in the process of chronic disease of periapical,and may be one of the important activity factors in periapical disease.MMP-2 and MMP-9 are expressed similarly inplasma cell, macrophage, fibroblast and neutrophil in periapical granuloma and periapical cyst. This study shows indirectly that the increasing expression of MMP-2,9 may speed up the destruction of inflammation in periapical tissues.The expression of MMP-2,9 in chronic periapical lesions have another significance. The inhibitors of MMP-2,9 may have potential clinical therapeutic value of periapical diseases in the future.