睾酮水平对牙周炎小鼠模型炎症性骨吸收的影响及机制探讨

目的：探讨睾酮水平对牙周炎小鼠模型炎症性骨吸收的影响及机制。方法：48只SD小鼠随机分为未结扎组、假手术组、去势组、去势+睾酮组4组,每组各12只,分别进行空白处理、去势模型和牙周炎模型构建。于结扎术后6周采集小鼠内眦静脉血,测定血清睾酮水平。处死小鼠后,取左侧上颌骨组织,进行苏木精-伊红染色和亚甲蓝染色,比较各组小鼠牙槽骨丧失量（alveolar bone loss,ABL）和牙槽骨吸收面积。利用实时荧光定量PCR测定牙龈组织中炎性细胞因子mRNA的表达,同时对血清睾酮水平与ABL、牙槽骨吸收面积及细胞因子进行相关性分析。采用SPSS 20.0软件包对数据进行统计学分析。结果：假手术组、去势组和去势+睾酮组小鼠血清睾酮水平显著低于未结扎组（P<0.05）;去势+睾酮组小鼠血清睾酮水平显著高于假手术组和去势组（P<0.05）;去势组小鼠血清睾酮水平显著低于假手术组（P<0.05）;去势+睾酮组小鼠ABL显著大于未结扎组、假手术组和去势组（P<0.05）,去势组小鼠ABL显著小于假手术组（P<0.05）;去势+睾酮组小鼠牙槽骨吸收面积显著大于未结扎组、假手术组和去势组（P<0.05）,去势组小鼠牙槽骨吸收面积显著小于假手术组（P<0.05）;假手术组、去势组和去势+睾酮组小鼠牙龈组织中白介素1β（IL-1β）mRNA、白介素6（IL-6）mRNA及肿瘤坏死因子α（TNF-α）mRNA水平显著高于未结扎组,白介素10（IL-10）mRNA水平显著低于未结扎组（P<0.05）;假手术组和去势组小鼠牙龈组织中IL-1β mRNA水平显著低于去势+睾酮组,去势组显著低于假手术组（P<0.05）;血清睾酮水平与ABL、牙槽骨吸收面积、IL-1β呈正相关（P<0.05）。结论：牙周炎小鼠睾酮水平降低,睾酮长期耗竭状态可减少牙槽骨炎症性骨吸收,可能通过降低IL-1β水平而实现。合理降低睾酮水平,有可能成为减少牙周炎患者牙槽骨吸收的治疗新思路。

Effect and mechanism of testosterone level on inflammatory bone resorption in periodontitis with mice

PURPOSE: To investigate the effect of testosterone level on inflammatory bone resorption in periodontitis with mice. METHODS: Forty-eight SD mice were randomly divided into unligated group, sham operation group, castration group, castration + testosterone group, 12 mice in each group. At 6 weeks after ligation, serum testosterone levels were measured, and alveolar bone loss (ABL) and alveolar bone absorption area were compared by hematoxylin - eosin staining and methylene blue staining. The expression of inflammatory cytokine messenger RNA(mRNA) in gingival tissue was measured by real-time fluorescence quantitative PCR. SPSS 20.0 software package was used to analyze the data. RESULTS: Serum testosterone level among four groups was the highest in the unligated group, followed by castration + testosterone group, sham operation group and castration group, with significant difference(P<0.05). The ABL of the castration + testosterone group was significantly larger than that of the unligated group, the sham operation group and the castration group(P<0.05). The ABL of the castration group was significantly smaller than that of the sham operation group (P<0.05). The alveolar bone resorption area of the castration + testosterone group was significantly larger than that of the unligated group, the sham operation group and the castration group(P<0.05). The alveolar bone resorption area of the castration group was significantly smaller than that of the sham operation group (P<0.05). Interleukin-1β (IL-1β) mRNA, interleukin-6(IL-6) mRNA and tumor necrosis factor-α(TNF-α) mRNA levels in gingival tissues of sham operation group, castration group and castration + testosterone group were significantly higher than the unligated group. The levels of interleukin-10(IL-10) mRNA in gingival tissues of sham operation group, castration group and castration + testosterone group were significantly lower than those in unligated group(P<0.05). The level of IL-1β mRNA in gingival tissues among four groups was the the highest in the unligated group, followed by castration + testosterone group, sham operation group and castration group, with significant difference (P<0.05). Serum testosterone levels were positively correlated with ABL, alveolar bone resorption area, and IL-1β (P<0.05). CONCLUSIONS: Periodontitis with mice have decreased testosterone levels, and long-term testosterone depletion can reduce inflammatory bone resorption in alveolar bone, which may be achieved by reducing the level of IL-1β, indicating that reduction of the level of testosterone in periodontitis patients may be a new treatment target for alveolar bone resorption.