Expression And Significance Of Matrix Metalloproteinase-8mRNA 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 MMP-8 is very low and steady in normal tissues , but the stimulation of proinflammatory cytokines, hormones, and cell growth factor can increase its expression. MMPs can degrade extracellular matrix and basement membrane proteins in joint in chronic inflammation and bone damage. MMP-8 called neutrophil collagenase.MMP-8 not only express in neutrophils, also in odontoblast, pulp cells, epithelial cells, plasma cells, macrophages, mesenchymal cells and some derivatives. MMP-8 main decompose interstitial collagen type I. Periapical disease is caused by avariety of stimulating inflammatory, often involving the alveolar bone and adjacent apical the cementum. Its main feature is periapical cementum and alveolar bone destruction. Extracellular matrix of cementum and alveolar bone mainly contain organic type I. Chronic periapical disease mainly contain periapical granulomatous and radicular cysts. The studies of expression of MMP-8 in periapical granulomatous and radicular cysts can not only understand the relationship between periapical disease and MMP-8, 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-8(MMP-8) mRNA in periapical granuloma and periapical cyst and discuss the significance .Methods Using reverse transcriptase polymerase chain reaction (RT-PCR) method for the detection of 22 cases of periapical granuloma, 11 cases of radicular cyst and 10 cases of normal tissue. After electrophoresis we measure thegray scale and area of electrophoresis band, multiply gray scale by area, then divide MMP-8 byβ-actin and again the result as the relative expression of MMP-8 mRNA of the tissues. Data using SPSS 10.0 software for data analysis. Using—X±s for the demonstration of measurement data. The comparison of means between the two groups use independent sample t test. The data were analyzed by chi-square test and Fisher's exact. We define the difference was significant if P<0.01.Results The positive rates and the level of MMP-8mRNA were significantly higher in apical granulomas and periapical cysts than those in normal tissue. (p<0.01) .When periapical granuloma group compared with radicular cysts group, the relative expression MMP-8mRNA have no significant difference (P> 0.01).Conclusion MMP-8 participate in the development of periapical granuloma and radicular cyst, and is likely to play an important role. The results also indirectly confirmed macrophages and plasma cells can secret MMP-8 in additionto polymorphonuclear leukocytes in the periapical granuloma and radicular cyst. The expression of MMP-8 in chronic periapical lesions have another significance. The inhibitor of MMP-8 may have potential clinical therapeutic value of periapical disease in the future.