Expression And Significance Of MMP-28 In Oral Lichen Planus

ObjectiveOral Lichen Planus(OLP)was the second most frequently occurring oral mucosa disease,the incidence rate was about 0.51%.Skin and oral mucosa may affect respectively or at the same time.Because of long-time erosive lesion may turn into canceration,WHO enrolled this disease as precancerous condition.Its typical histopathological characterist was parakeratosis of epithelial cells,colliquation of basal cell and coarctate leukomonocytes of lamina propria arranged in a row.The epithelial pegs extended irregularlly.The basal cell arranged confusedly,and the limit of basal membrane was unclear.Conspicuous colliquation of basal cell may form blisters underneath the epithelium.Matrix metalloproteinase-28 was cloned and identified in 2001.It was initiately cloned from human skin Keratinocyte,so we call it"Epilysin".In injured skin tissue, MMP-28 expressed significantly in basal Keratinocyte far from wound edge.Studies showed that normal scar didn't express MMP-28 anyway,but hypertrophic scar all expressed MMP-28.So,it was concluded that MMP-28 participate in the restructure of basal membrane.Oral membrane had the same tissue structure as skin,and they had similar histopathological characterist,we presume that MMP-28 has the similar expression in oral membrane.IHC,RT-PCR and Western blot were used to evaluate protein and mRNA level of MMP-28 in human OLP tissues.The purpose was to explore the relationship between the expression of MMP-28 and different clinical types and to investigate their biological mechanisms to provide some theoretic basis for the effective treatment. MethodsThirty-seven OLP patients were collected and classified into 3 groups according to the clinical and pathological diagnose:reticular,plaque and erosive.Meanwhile,eleven normal oral mucosas were also collected as controls.Immunohistochemistry,RT-PCR and Western blot were used to examine the expression of MMP-28 at the level of protein and mRNA.ANOVA was used to analyze the integral optical density and relative density and SNK-q Test was used to compare with each two groups.Results1.Immunohistochemical stainingThe staining was brown in cytoplasm of epidermis and lamina propria,which was the positive expression of MMP-28 in OLP tissues.The expression of MMP-28 in OLP groups were significantly higher than those in controls(P<0.05),and the expression of MMP-28 in erosive group was significantly higher than those in reticular group and plaque group(P<0.05),but no significant difference was found between reticular and plaque group(P＞0.05).2.RT-PCRThe expression of MMP-28mRNA was detected with different intensity in every group.The expression of MMP-28 in OLP groups were significantly higher than those in controls(P<0.05),and the expression of MMP-28 in erosive group was significantly higher than those in reticular group and plaque group(P<0.05),but no significant difference was found between reticular and plaque group(P＞0.05).3.Western blotThe expression of MMP-28 protein was detected with different intensity in every group.The expression of MMP-28 in OLP groups were significantly higher than those in controls(P<0.05),and the expression of MMP-28 in erosive group was significantly higher than those in reticular group and plaque group(P<0.05),but no significant difference was found between reticular and plaque group(P＞0.05). Conclusions1.The expression level of MMP-28 protein and mRNA existed in OLP tissues,which were obviously higher than normal mucosa.2.The expression level of MMP-28 protein and mRNA in erosive group were obviously higher than reticular and plaque group.3.MMP-28 was critically involved in OLP.