M1型巨噬细胞对慢性牙周炎模型小鼠免疫状态的影响

Effect of M1 macrophages on immune status in chronic periodontitis model mice

目的:探讨M1型巨噬细胞对牙龈卟啉单胞菌诱导的慢性牙周炎模型小鼠免疫状态的影响,阐明M1型巨噬细胞在慢性牙周炎中的作用。方法:10只7周龄C57BL/6雌性小鼠随机分为对照组(n=5)和慢性牙周炎组(n=5)。以牙龈卟啉单胞菌涂抹小鼠口腔建立慢性牙周炎模型。测量2组小鼠从釉牙骨质界(CEJ)到牙槽嵴顶(ABC)的距离,评价牙槽骨吸收情况;HE染色法观察2组小鼠牙周组织中炎性细胞浸润、结缔组织附着丧失和牙槽骨吸收情况;流式细胞术检测2组小鼠牙龈组织中F4/80^+iNOS^+M1型巨噬细胞百分率和细胞数;实时定量PCR法检测2组小鼠牙龈组织中M1型巨噬细胞相关因子iNOS mRNA表达水平。结果:与对照组比较,慢性牙周炎组小鼠CEJ至ABC的距离明显增加(P<0.01);与对照组比较,慢性牙周炎组小鼠牙龈结合上皮附着位于CEJ的根方,ABC吸收变平,可见破骨细胞和骨吸陷窝形成;慢性牙周炎小鼠牙龈组织中M1型巨噬细胞百分率和细胞数明显高于对照组(P<0.01);慢性牙周炎小鼠牙龈组织中iNOS mRNA表达水平高于对照组(P<0.01)。结论:在慢性牙周炎小鼠模型中,M1型巨噬细胞介导的免疫应答增强,M1型巨噬细胞参与慢性牙周炎的炎症反应和组织损伤。

Objective:To investigate the effect of M1 macrophages on the immune status of the model mice with porphyromonas gingival(P.gingivalis)-induced chronic periodontitis,and to clarify the role of M1 macrophages in chronic periodontitis.Methods:Ten 7-week-old female C57BL/6 mice were randomly divided into control group(n=5)and chronic periodontitis group(n=5).The chronic periodontitis models of mice were induced by oral infection with P.gingivalis.The resorption of alveolar bone of the mice in two groups was estimated by measuring the distance from the cemento-enamel junction(CEJ)to the alveolar bone crest(ABC);HE staining was performed to examine the infiltration of inflammatory cells,attachment loss of connective tissue and resorption of alveolar bone in periodontal tissue of the mice in two groups.flow cytometry was used to detect the percentages and number of F4/80^+iNOS^+M1 macrophages in gingival tissue of the mice in two groups;real-time quantitative PCR method was used to detect the expression levels of iNOS mRNA in gingival tissue of the mice in two groups.Results:Compared with control group,the distance from CEJ to ABC of the mice in chronic periodontitis group was increased significantly(P<0.01);the gingival junction epithelium attached to the root side of CEJ,and the absorption of ABC became flat,the osteoclasts and bone resorption lacunae of the mice in chronic periodontitis group were found.The number and percentage of M1 macrophages in gingival tissue of the mice in chronic periodontitis group were significantly higher than those in control group(P<0.01).Compared with control group,the expression level of iNOS mRNA in gingival tissue of the mice in chronic periodontitis group was significantly increased(P<0.01).Conclusion:In the mouse model of chronic periodontitis,the immune response mediated by M1 macrophages is enhanced,and M1 macrophages are involved in the inflammatory response and tissue damage of chronic periodontiti.