局部应用辛伐他汀对拔牙窝内BMP-2 mRNA表达的影响及意义

Effects of simvastatin on BMP-2 mRNA expression in alveolar bone following tooth extraction and significance

目的:探讨局部应用辛伐他汀对拔牙窝内骨形成蛋白(BMP)-2mRNA表达的影响,阐明其作用机制。方法:选用健康雄性Wistar大鼠56只,随机分为实验组28只和对照组28只,拔除右下颌中切牙后,实验组即刻植入载辛伐他汀聚乳酸-羟基乙酸共聚物(PLGA)支架材料,对照组植入单纯PLGA支架材料作为对照,于术后5d、1周、2周和4周分别处死大鼠,设计针对BMP-2mRNA的寡核苷酸探针,采用原位杂交技术检测拔牙窝BMP-2mRNA的表达。结果:术后5d,实验组和对照组均未见有BMP-2mRNA阳性表达细胞;术后1周,实验组植入材料和牙槽窝骨壁之间的间充质细胞内可见染色较深的阳性细胞,而对照组偶见染色较浅的阳性细胞;术后2周,实验组在植入材料和牙槽窝骨壁之间的间充质细胞内可见较多颗粒清晰的阳性细胞,新形成的类骨质表面成骨细胞内也有BMP-2mRNA阳性表达,阳性细胞数明显多于对照组;术后4周,实验组和对照组均可见BMP-2mRNA阳性表达细胞。术后1周、2周、4周实验组BMP-2mRNA阳性细胞数明显多于对照组(P<0.05)。结论:局部应用辛伐他汀可通过增加BMP-2mRNA的表达促进拔牙窝骨损伤的愈合。

Objective To investigate the effect of local application of simvastatin on the expression of bone morphogenetic protein-2 （BMP-2）in the tooth socket following tooth extraction and discuss its mechanism. Methods Fifty-eight male Wistar rats were divided into experimental group and control group（n=28）.PLGA was immediately implanted with or without simvastatin into extraction sockets of the mandibular incisors. Oligonucleotide probe specific to BMP-2mRNA was designed,and hybridization technique was conducted 5d,1week,2weeks and 4weeks after implantation.Results There were no positive cells in both experimental group and control group 5dafter implantation.There were deep-dying positive stromal cells between the implanted material and the wall of tooth socket in experimental group,and a few light-dying positive cells could be seen in control group 1week after implantation.There were many positive cells with clear particles in the stromal cells between the implanted material and the wall of tooth socket,and there were also BMP-2 mRNA positively expressed cells on the surface of newly-formed osteoid in two groups,and the number of the positive cells in experimental group was higher than that in control group 2weeks after implantation.There were BMP-2mRNA positive cells in both the experimental group and the control group 4weeks after implantation.The number of BMP-2positive cells in experimental group was significantly higher than that in control group 1,2,4weeksafter implantation（P〈0.05）.Conclusion Topical application of simvastain could promote alveolar bone repair by upregulating BMP-2mRNA expression.