正畸应力变化下牙龈组织α-SMA、Ⅰ型和Ⅲ型胶原变化及龈沟液MMP-2、TIMP-2的表达

Changes of α-SMA, type Ⅰ and type Ⅲ collagen in gingival tissue and expression of MMP-2 and TIMP-2 in gingival crevicular fluid under orthodontic force

目的:探讨正畸应力变化下牙龈组织α平滑肌肌动蛋白(α-SMA)、Ⅰ型及Ⅲ型胶原变化以及龈沟液基质金属蛋白酶2(MMP-2)、金属蛋白酶组织抑制因子2(TIMP-2)的表达。方法:选取南昌大学附属口腔医院2018年4月—2019年4月收治的正畸患者74例,随机分为A组(24例,0 g力)、B组(25例,75 g力)、C组(25例,150 g力)3组。于加力0、4周采集患者部分牙龈组织,采用免疫组织化学染色法检测α-SMA、Ⅰ型及Ⅲ型胶原表达水平。在加力后0、2、4周收集龈沟液,采用酶联免疫吸附法检测MMP-2、TIMP-2表达水平。采用Spearman相关性分析不同正畸应力与α-SMA、Ⅰ型胶原、Ⅲ型胶原、MMP-2、TIMP-2表达水平的相关性。采用SPSS 19.0软件包对数据进行统计分析。结果:加力2周及加力4周,3组患者龈沟液MMP-2、TIMP-2表达水平依次升高(P<0.05);加力4周后,3组患者牙龈组织中α-SMA、Ⅰ型及Ⅲ型胶原水平依次升高(P<0.05);不同正畸应力与MMP-2、TIMP-2、α-SMA、Ⅰ型胶原及Ⅲ型胶原表达水平均呈正相关(P<0.05)。结论:龈沟液TIMP-2、MMP-2表达水平以及肌成纤维细胞表达与正畸应力变化有关,可能在正畸治疗的牙周组织改建中发挥重要作用。

PURPOSE:To investigate the changes of α-smooth muscle actin(α-SMA),type Ⅰ and type Ⅲ collagen in gingival tissue and expression of matrix metalloproteinase-2(MMP-2) and tissue inhibitor of metalloproteinase-2(TIMP-2)in gingival crevicular fluid under orthodontic force.METHODS:Seventy-four patients undergoing orthodontic treatment in Affiliated Stomatological Hospital of Nanchang University from April 2018 to April 2019 were enrolled,and randomly divided into three groups.Group A(n=24) received the treatment under 0 g of orthodontic force,group B(n=25) under 75 g of orthodontic force,and group C(n=25) under 150 g of orthodontic force.At the baseline and 4 th week of treatment,the expression levels of α-SMA,type Ⅰ collagen and type Ⅲ collagen in gingival tissues were detected by immunohistochemical staining.At the baseline,the 2 nd,and 4 th week of treatment,the expression levels of MMP-2 and TIMP-2 in gingival crevicular fluid were detected by enzyme-linked immunosorbent assay.Then the correlation between different orthodontic force and levels of α-SMA,type Ⅰ collagen,type Ⅲ collagen,MMP-2 and TIMP-2 was analyzed using Spearman correlation analysis.Statistical analysis was completed by SPSS 19.0 software package.RESULTS:At the 2 nd and 4 th week of treatment,the expression levels of MMP-2 and TIMP-2 in gingival crevicular fluid among three groups were the lowest in group A,followed by group B and group C(P<0.05).At the 4 th week of treatment,the levels of α-SMA,type Ⅰ and typeⅢ collagen in gingival tissues among three groups were the lowest in group A,followed by group B and group C(P<0.05).The orthodontic force was positively correlated with expression levels of α-SMA,type Ⅰ collagen,type Ⅲ collagen,MMP-2 and TIMP-2(P<0.05).CONCLUSIONS:The expression levels of MMP-2 and TIMP-2 in gingival crevicular fluid and myofibroblast are related to the changes of orthodontic force,which may play an important role in the reconstruction of periodontal tissue during orthodontic treatment.