牙体机械损伤后牙本质牙髓组织MMP-2和MMP-9表达变化

目的 研究牙体机械损伤后牙本质牙髓组织中基质金属蛋白酶-2(MMP-2)和基质金属蛋白酶-9(MMP-9)表达的变化.方法 以离体第三磨牙(n=30)制作牙体机械损伤的牙本质牙髓复合体体外培养模型(模型组).分别于培养后第3、7、14天收集样本,免疫组化染色、Real-time PCR和Western blotting检测MMP-2和MMP-9在培养后不同时间点的表达.以无牙体损伤的牙本质牙髓复合体培养的离体第三磨牙(n=30)作为对照组.结果 免疫组化染色发现,MMP-2和MMP-9在对照组成牙本质细胞呈阳性表达,在牙髓细胞则呈阴性表达;在模型组,成牙本质细胞和牙髓细胞MMP-2和MMP-9均呈阳性表达.图像分析显示,模型组培养后各时间点MMP-2和MMP-9表达均显著高于对照组(P<0.05);且模型组培养第3天MMP-2和MMP-9表达均显著高于培养第7和第14天(P<0.05).Real-time PCR检测表明,模型组培养后第3天的MMP-2和MMP-9 mRNA表达显著高于培养后第7和第14天(P<0.05).Western blotting检测发现,模型组培养后各时间点均有MMP-2和MMP-9蛋白表达,以培养后第3天时较为明显.结论 在牙体损伤的牙本质牙髓复合体培养过程中,MMP-2和MMP-9表达呈现先增加后减弱,与基质降解和合成的时间相对应.

Expression of MMP-2 and MMP-9 in dentin-pulp complex after mechanical injury

Objective To detect the expression of matrix metalloproteinase(MMP)-2 and MMP-9 in dentin-pulp complex after mechanical injury. Methods The in vitro culture models of dentin-pulp complex after mechanical injury were prepared with third molars(model group,n=30).Samples were collected 3,7 and 14 d after culture,and immunohistochemical staining,Real-time PCR and Western blotting were employed to detect the expression of MMP-2 and MMP-9 at different time points after culture.And the third molars cultured in vit...