IL-17A对小鼠实验性牙周炎骨破坏作用研究

Effects of IL-17A on bone destruction in experimental periodontitis of mice

目的:通过构建白介素-17A(interleukin-17A,IL-17A)基因敲除小鼠实验性牙周炎模型,初探IL-17A参与调控牙周炎骨破坏的机制。方法:选用雄性IL-17A基因敲除(knock out,KO)的C57BL/6小鼠和相同基因背景的野生型(wild type,WT)C57BL/6小鼠,通过结扎和喂菌诱导小鼠实验性牙周炎,WT小鼠及KO小鼠均分为正常对照组和牙周炎组。确认结扎4周后处死小鼠收集上颌骨,进行Micro-CT断层成像、HE染色、抗酒石酸酸性磷酸酶(tartrate-resistant acid phosphatase,TRAP)染色、免疫组化和组织病理学分析。结果:在喂菌和结扎诱导的小鼠实验性牙周炎模型中,在Micro-CT的三维重建及近远中向截面上,KO小鼠较WT小鼠牙槽骨吸收减少,KO小鼠上颌第二磨牙牙槽嵴顶到釉牙骨质界的近中线性距离为(0.51±0.11)mm,远中为(0.45±0.04)mm,显著低于WT小鼠的近中(0.61±0.09)mm和远中(0.65±0.08)mm(P <0.05);KO小鼠骨体积分数比为41.88±1.82,显著高于WT小鼠的36.55±2.08(P <0.05);KO小鼠骨密度为84.39±2.11,显著高于WT小鼠的76.90±2.55(P <0.05);HE染色中可见牙槽骨吸收减少;TRAP染色中可见TRAP染色阳性细胞减少;免疫组化结果显示牙周组织核因子κB受体活化因子配体(receptor activator of nuclear factorκB ligand,RANKL)的表达降低。结论:牙周炎中IL-17A可能有促进牙周炎发生发展及促进牙槽骨吸收的作用。

Objective:This study aimed to investigate the role of interleukin 17 A(IL-17 A)in the regulation of bone destruction in experimental periodontitis model.Methods:Male IL-17 A knockout C57 BL/6 mice and C57 BL/6 wild type mice induced with ligation and Porphyromonasgingivalis infection were used to establish experimental periodontitis model in this study.Wild type mice and IL-17 A knockout mice were divided into the normal group and the periodontitis group,respectively.The experimental periodontitis model mice were sacrificed 4 weeks after ligation to collect maxillary bones.Micro-computed tomography(Micro-CT),HE staining,TRAP staining,immunohistochemistry and histopathological analysis were performed to reveal the role of IL-17 A on bone destruction and inflammation.Results:In the experimental periodontitis mice model induced with Porphyromonasgingivalis infection and ligation,IL-17 A knockout mice showed less alveolar bone resorption in the three-dimensional reconstruction of Micro-CT than wild-type mice did.The mesial and distal linear distance from the alveolar bone crest(ABC)to the cementoenamel junction(CEJ)of maxillary second molars in the IL-17 A knockout mice was(0.51±0.11)mm and(0.45±0.04)mm respectively,significantly less than those in wild-type mice(P<0.05),which was(0.61±0.09)mm and(0.65±0.08)mm respectively.In addition,compared to wild-type mice,the mean bone volume fraction in IL-17 A knockout mice was 41.88±1.82,significantly higher than that in wild-type mice(36.55±2.08,P<0.05),and the bone mineral density in IL-17 A knockout mice was 84.39±2.11,significantly higher than that in wild-type mice(76.90±2.55,P<0.05).On the other hand,IL-17 A knockout mice exhibited significantly less alveolar bone resorption in periodontal tissue in HE staining than wild-type mice;TRAP-positive cells and the expression of receptor activator of nuclear factorκB ligand(RANKL)in periodontal tissue were reduced as well.Conclusion:IL-17 A may promote the development of periodontitis and alveolar bone resorption.