益生菌对卵巢摘除致雌激素缺乏小鼠牙周组织中IL-17表达的影响及其意义

目的：探讨益生菌干预对雌激素缺乏小鼠牙周组织中白细胞介素17（IL-17）表达的影响，阐明雌激素缺乏与牙周炎关联性的可能机制。方法：选取8周龄健康雌性C57BL/6J小鼠15只，随机分为假手术组、卵巢摘除组和益生菌干预组（卵巢摘除术后行益生菌灌服），每组5只。采用平均骨密度测量技术检测实验前后小鼠骨矿物质密度（BMD），实时荧光定量PCR（RT-qPCR）法检测小鼠骨髓细胞和牙龈组织中IL-17mRNA表达水平，流式细胞术检测小鼠骨髓中辅助性T细胞17（Th17）占CD4⁺ TCRβ⁺细胞的百分率。结果：与假手术组比较，卵巢摘除组小鼠BMD明显降低（P<0.05），骨髓细胞和牙龈组织中IL-17 mRNA表达水平均明显升高（P<0.05），Th17细胞占骨髓CD4⁺TCRβ⁺细胞百分率明显升高（P<0.05）；与卵巢摘除组比较，益生菌干预组小鼠BMD明显增加（P<0.05），骨髓细胞和牙龈组织中IL-17 mRNA表达水平均明显降低（P<0.05），Th17细胞占骨髓CD4⁺TCRβ⁺细胞百分率明显降低（P<0.05）；与假手术组比较，益生菌干预组小鼠股骨BMD、骨髓细胞和牙龈组织中IL-17 mRNA表达水平及Th17细胞占骨髓CD4⁺TCRβ⁺细胞百分率差异均无统计学意义（P>0.05）。结论：益生菌干预能阻止雌激素缺乏导致的小鼠牙周组织中IL-17水平升高，对雌激素缺乏引起的牙周炎具有预防作用。

Effect of probiotics on expression of IL-17 in periodontal tissue of estrogen-deficient mice induced by ovariectomy and its significance

Objective: To explore the effect of probiotic feeding on the interleukin-17 (IL-17) expression in periodontal tissue of the estrogen-deficient mice, and to elucidate the possible mechanism of the correlation between estrogen deficiency and the periodontitis susceptibility. Methods: A total of 15 female C57BL/J6 mice(8-week-old) were randomly divided into sham operation group, ovariectomy group and probiotics group (probiotics feeding after ovariectomy) (n=5). The bone mineral densities(BMD) of the mice in various groups before and after experiment were measured by mean bone density measurement technique and the IL-17 mRNA expression levels in bone marrow cells and gingiva tissus of the mice were determined by RT-qPCR. The percentages of Th17 cells in CD4⁺TCRβ⁺ B cells in bone marrow of the mice were measured by flow cytometry. Results: Compared with sham operation group, the BMD of femur of the mice in OVX group was significantly decreased (P<0.01), the expression levels of IL-17 mRNA in bone marrow cells and gingiva tissue were increased (P<0.01), and the percentage of CD4⁺TCRβ⁺Th17 cells in the bone marrow was increased(P<0.05).Compared with OVX group, the BMD of femur of the mice in probiotics group was significantly increased (P<0.01), the expression levels of IL-17 mRNA in bone marrow cells and gingiva tissue were decreased (P<0.01), and the percentage of CD4⁺TCRβ⁺Th17 cells in the bone marrow was decreased(P<0.05).Compared with sham operation group, the BMD of femur, the expression levels of IL-17 mRNA in bone marrow cells and gingiva tissue, and the percentage of CD4⁺TCRβ⁺Th17 cells in the bone marrow in probiotics group had no significant differences (P>0.05). Conclusion: Probiotics feeding can inhibit the upregulation of IL-17 mRNA level of the mice induced by estrogen deficiency, and has the preventive effect on the estrogen deficiency-induced periodontitis.