壳寡糖对牙周炎大鼠牙槽骨吸收及Th17/Treg平衡和OPG/RANKL/RANK通路的影响

目的: 探讨壳寡糖对牙周炎大鼠牙槽骨吸收及Th17/Treg平衡和OPG/RANKL/RANK通路的影响。方法: 建立牙周炎大鼠模型,随机分为模型组、壳寡糖低剂量组、壳寡糖中剂量组、壳寡糖高剂量组和甲硝唑组,每组12只,另取12只作为对照组。分组处理后,评估牙龈指数、牙槽骨吸收值;H-E染色观察牙周组织病理形态学变化;流式细胞术检测外周血中Th17/Treg细胞比值;酶联免疫吸附试验（ELISA）检测各组大鼠血清中IL-17、TGF-β、RANKL、OPG水平,实时荧光定量PCR（qRT-PCR）检测各组大鼠牙周组织OPG、RANKL mRNA表达水平。采用SPSS 24.0软件包对数据进行统计学分析。结果: 与对照组相比,模型组大鼠牙周组织呈现牙周膜纤维束断裂、排列紊乱,毛细血管扩张、增生,炎症细胞浸润等病理损伤;牙龈指数、牙槽骨吸收值、Th17/Treg比值、血清RANKL及IL-17水平、牙周组织RANKL mRNA水平显著升高（P<0.05）,血清OPG及TGF-β水平、牙周组织OPG mRNA水平显著降低（P<0.05）。与模型组相比,壳寡糖低、中、高剂量组和甲硝唑组大鼠牙周组织病理损伤减轻;牙龈指数、牙槽骨吸收值、Th17/Treg比值、血清RANKL及IL-17水平、牙周组织RANKL mRNA水平显著降低（P<0.05）,血清OPG及TGF-β水平、牙周组织OPG mRNA水平显著升高（P<0.05）,且壳寡糖各组呈剂量依赖性,壳寡糖高剂量组与甲硝唑组相比,差异无统计学意义（P>0.05）。结论: 壳寡糖可促使Th17/Treg平衡恢复正常,上调OPG表达,下调RANKL表达,抑制牙周炎大鼠牙槽骨吸收,改善其临床症状。

Effects of chitosan oligosaccharide on alveolar bone resorption,Th17/Treg balance and OPG/RANKL/RANK pathway in periodontitis rats

PURPOSE: To investigate the effect of chitosan oligosaccharide on alveolar bone resorption, Th17/Treg balance and OPG/RANKL/RANK pathway in rats with periodontitis. METHODS: Rat model of periodontitis was established, and the periodontitis rats were randomly divided into model group, low-dose chitosan oligosaccharide group, middle-dose chitosan oligosaccharide group, high-dose chitosan oligosaccharide group and metronidazole group, with 12 rats in each group, another 12 rats were set as control group. After treatment, gingival index and alveolar bone absorption were evaluated. H-E staining was used to observe the pathological changes of periodontal tissues. The ratio of Th17/Treg cells in peripheral blood was detected by flow cytometry, the levels of serum IL-17, TGF-β, RANKL and OPG were detected by ELISA, and the expressions of OPG and RANKL mRNA in periodontal tissues of rats in each group were detected by real-time fluorescent quantitative PCR(qRT-PCR). SPSS 24.0 software package was used to analyze the data. RESULTS: Compared with the control group, the periodontal tissue of the model group showed periodontal membrane fiber bundle rupture, disordered arrangement, capillary expansion, proliferation, inflammatory cell infiltration and other pathological damage. Gingival index, alveolar bone resorption value, Th17/Treg ratio, serum RANKL and IL-17 levels, and periodontal RANKL mRNA level were significantly increased(P<0.05), while the levels of serum OPG, TGF-β and OPG mRNA in periodontal tissues were significantly decreased (P<0.05). Compared with the model group, the pathological damage of periodontal tissue in the low-middle-and high-dose chitosan oligosaccharide groups and metronidazole group was reduced; gingival index, alveolar bone resorption value, Th17/Treg ratio, serum RANKL and IL-17 levels, and periodontal RANKL mRNA level were significantly decreased(P<0.05), while the levels of serum OPG, TGF-β and OPG mRNA in periodontal tissues were significantly increased(P<0.05); there was a dose-dependent relationship between the chitosan oligosaccharide groups, and there was no significant difference between the high-dose chitosan oligosaccharide group and metronidazole group(P>0.05). CONCLUSIONS: Chitosan oligosaccharide can promote Th17/Treg balance to return to normal, up-regulate OPG expression, down-regulate RANKL expression, inhibit alveolar bone resorption in periodontitis rats and improve their clinical symptoms.