Objective: To illuminate the temporal expression of the triggering receptor expressed on myeloid cells-1 (TREM-1) in the experimental periodontitis in rat and to investigate the function of TREM-1 in the pathogenesis of experimental periodontitis in rat. Methods: The experimental periodontitis model was established in the maxillary first molar by means of 'wire ligation + vaccination periodontal pathogen Porphyromanus gingivalis (Pg) + high-sugar diet' in Sprague-Dawley (SD) rats. The experimental animals were divided into six groups: the control group and each of the time points of establishing the models for one week and two to five weeks. There were six rats for each of the six groups. The bone loss of the palatal site was calculated to estimate whether the periodontitis model was successfully established. The expression of TREM-1, proinflammatory cytokines: tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-6, anti-inflammatory cytokines: IL-4, IL-10 and transforming growth factor-β (TGF-β) were examined by using quantitative real-time PCR. The expression level of TREM-1 protein was analyzed by the method of immunohistochemistry. Results: The average bone loss area of the palatal site was (0.17±0.04) mm(2) in the group of three weeks and was statistically significant (P<0.05) compared to the control group [(0.10±0.01) mm(2)]. The experimental periodontitis model was successfully established in the group of three weeks. The expression of TREM-1 increased significantly in the inflamed periodontal tissues and reached to its maximum expression in the three weeks group accounting for 159.50±38.26 in protein expression and 4.35±0.60 in mRNA expression, respectively. TREM-1 expression difference between the three weeks group and control group was statistically significant (P<0.01). The expression of IL-6 by gingival tissues was correlated with the mRNA level of TREM-1 (r=0.813 P=0.049). Conclusions: TREM-1, as a proinflammatory receptor, could facilitate the periodontal inflammatory response. The possible way of TREM-1 to promote inflammation may be through controling the expression of IL-6.
目的： 探索大鼠实验性牙周炎发展过程中髓样细胞触发受体1（triggering receptors expressed by myeloid cells-1，TREM-1）的时序性表达，进一步探讨TREM-1在牙周炎发病机制中的作用。 方法： 将36只5周龄雄性Sprague-Dawley大鼠分为实验组（30只）和对照组（基线组，6只），对30只实验组大鼠采用"丝线结扎+接种牙龈卟啉单胞菌（Porphyromanus gingivalis，Pg）+高糖饮食"的方法建立大鼠上颌第一磨牙实验性牙周炎模型，分为建模1周组、2周组、3周组、4周组和5周组，每组6只，通过检测大鼠上颌第一磨牙区牙槽骨的破坏情况判断牙周炎模型是否成功。通过实时荧光定量PCR检测各组大鼠上颌第一磨牙区牙龈组织中TREM-1，促炎细胞因子肿瘤坏死因子α（tumor necrosis factor-α，TNF-α）、白细胞介素（interleukin，IL）1β、IL-6，抗炎细胞因子IL-4、IL-10及转化生长因子β（transforming growth factor-beta，TGF-β）的表达。免疫组织化学法检测各组大鼠TREM-1的蛋白表达。 结果： 建模3周组大鼠上颌第一磨牙腭侧由釉质牙骨质界、近远中轴角线及牙槽嵴顶围成面积[（0.17±0.04）mm(2)]与对照组[（0.10±0.01）mm(2)]相比差异有统计学意义（P<0.05），提示建模3周牙周炎模型诱导成功。TREM-1蛋白和mRNA的表达在牙周炎症发展过程中均升高，在建模3周组达峰值，蛋白表达的A值为（159.50±38.26），mRNA的相对表达量为（4.35±0.60），与对照组（TREM-1蛋白表达A值和mRNA表达分别为10.04±2.00、1.01±0.12）相比差异均有统计学意义（P<0.01）。炎症因子IL-6的mRNA表达与TREM-1的mRNA表达呈正相关关系（r=0.813，P=0.049）。 结论： TREM-1是一种促炎受体蛋白，可促进牙周炎症的进展，其作用可能通过调节IL-6的表达来实现；调节TREM-1的表达，可为牙周炎症相关性疾病的诊疗带来新的思路。.
Keywords: Immunomodulation; Models, animal; Periodontitis; Triggering receptors expressed by myeloid cells-1.