糖尿病大鼠颌骨缺损区骨再生和巨噬细胞表型的研究

Study on the bone regeneration and phynotypes of macrophages in alveolar bone defects of diabetic rats

目的:研究糖尿病大鼠颌骨缺损的成骨效果及巨噬细胞表型的变化。方法:Wistar大鼠及GK大鼠各9只,分别为对照组与实验组。于双侧第一磨牙前牙槽嵴顶做箱状骨缺损,分别于术后即刻、1周、4周取材,通过Micro-CT观察,对比骨体积分数(BV/TV)、骨小梁数量(Tb.N)、骨小梁厚度(Tb.Th)、骨小梁分离度(Tb.Sp);HE、Masson染色,免疫组化RUNX2、DMP1、iNOS、CD206染色,并对结果统计学分析。结果:影像学检测4周时BV/TV、Tb.N、Tb.Th实验组均低于对照组,差异有统计学意义;Tb.Sp实验组高于对照组,差异无统计学意义。组织学检测HE染色4周时,新生骨面积实验组小于对照组,差异有统计学意义。Masson染色实验组新生骨的形成较对照组少。免疫组化各时间段一定视野下实验组成骨前体细胞数及成熟骨细胞数均小于对照组。M1型巨噬细胞数量4周时实验组大于对照组。M2型巨噬细胞数量各时间点实验组均小于对照组,以上差异均有统计学意义(P<0.05)。结论:糖尿病大鼠颌骨缺损比普通大鼠骨再生能力差,其差异与巨噬细胞表型M1/M2的变化有关。

Objective:To study the osteogenic effect and the changes of macrophage phenotype in mandibular bone defect of diabetic rats.Methods:Bone defects were made at the crest of the alveolar ridge of both sides in Wistar rats(non-diabetic model,control group)and GK rats(diabetic model,experimental group).The mandibles of rats were taken and processed for micro-computed tomography(Micro-CT)and histochemistry staining immediately after surgery,1 week and 4 weeks after the operation,respectively.Immunohistochemical staining of RUNX2,DMP1,iNOS,and CD206 was used to detect osteoblasts and different phenotypes of macrophages.Results:Micro-CT results at 4 weeks after the operation displayed that the bone volume fraction(BV/TV),bone trabecular thickness(Tb.Th)and bone trabecular number(Tb.N)in the experimental group were significantly lower than those in the control group.The trabecular separation(Tb.Sp)of the experimental group was higher than that of the control group,although the difference was not statistically significant.HE staining and Masson staining showed less bone formation and smaller new bone area in the experimental group than in the control group.Immunohistochemical staining indicated fewer bone precursor cells and mature bone cells in the experimental group than in the control group under certain fields of view at different periods.Notably,the number of M2 macrophages in the experimental group was lower than that in the control group at all time points,and the number of M1 macrophages in the experimental group remained high at 4 weeks(P<0.05).Conclusion:The bone regeneration of diabetic rats with jaw defects is inferior to non-diabetic rats,which is probably related to the change of macrophage phenotype from M1 to M2.