Objective To observe the expressions of matrix metalloproteinase (MMP)-2, MMP-9 and MMP-8 in healthy and carious teeth, and discuss the role of MMP in caries development. Methods The expressions of MMP-2, MMP-9 and MMP-8 were analyzed by gelatin enzymography, Western blot and immunohistochemistry methods. Results The immunohistochemical staining showed that there were expressions of MMP-2, MMP-9 and MMP-8 in odontoblasts of healthy and carious teeth, which were weakly positive in healthy teeth and strongly positive in caries teeth. Western blot detected a MMP-8 protein band (molecular weight of 5×104) in odontoblasts of healthy and carious teeth, which was significantly higher in carious teeth group than that of healthy teeth group (P < 0.05). The zymogen and active enzyme of MMP-2 were detected, but only the zymogen form of MMP-9 was detected in healthy teeth group. The expressions of MMP-2 and MMP-9 were significantly higher in carious teeth group than those of healthy teeth group (P < 0.05). Conclusion MMP might play important roles in the progression of dental caries.%目的 比较基质金属蛋白酶(MMP)-2、MMP-9、MMP-8在健康牙齿和龋齿中的表达,探讨MMP在龋病进展中的作用.方法 选取健康第三磨牙和龋病第三磨牙各30个,利用明胶酶谱、Western-blot、免疫组化的方法,对比研究MMP-2、MMP-9、MMP-8在健康牙齿和龋齿中的表达.结果 免疫组化染色显示,3种蛋白在健康牙齿和龋齿成牙本质细胞层均有表达,且在健康牙齿中呈弱阳性,在龋齿中成强阳性.在健康和龋病成牙本质细胞上清液中均检测到一条相对分子质量为5×104的MMP-8条带,且其在龋齿成牙中的表达强度(22.71±1.73)高于健康牙齿(17.22±1.22),差异有统计学意义.在健康牙齿本质细胞培养液中,可检测到MMP-2的酶原和活性酶,MMP-9仅有酶原形式,龋齿组中MMP-2、MMP-9的水平(10.26±1.89)、(6.74±2.43)高于相应健康组(6.62±1.68)、(2.60±1.08),差异有统计学意义.结论 MMP-2、MMP-9、MMP-8可能在龋病进展中发挥作用.
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