【摘要】 背景:研究发现大鼠牙卵泡中髓样分化因子88有表达,并影响牙齿的萌出和破骨细胞数量。目的:进一步验证髓样分化因子88在大鼠根尖周炎动物模型中的表达。方法:选取6周龄雄性SD大鼠25只,由大连医科大学SPF动物实验中心提供。将大鼠下颌第1磨牙开髓,建立大鼠实验性根尖周炎模型,并将开髓0周作为对照组;开髓1,2,3,4周作为实验组。开髓后于各时间点随机选取5只大鼠,麻醉后取材,用多聚甲醛固定下颌骨,组织脱钙,制作冷冻切片。分别用苏木精-伊红染色、免疫组织化学染色观察根尖组织炎症区域的病理变化,并用RT-PCR检测髓样分化因子88在实验性根尖周炎模型中的表达。结果与结论:(1)苏木精-伊红染色:结果显示实验组的根尖区有炎症浸润,并向周围蔓延扩展,表明成功建立了大鼠实验性根尖周炎动物模型;(2)免疫组织化学染色:结果显示髓样分化因子88在1,2,3,4周4个时间点根尖周炎症区域中均呈阳性表达,髓样分化因子88阳性细胞的表达量在1-3周明显增加,并在第3周时出现高峰;而在4周时,其表达量降低;仅少量髓样分化因子88阳性细胞出现在正常对照组;(3)RT-PCR结果显示髓样分化因子88 mRNA表达量从1-3周逐渐增高,到第4周下降;(4)结果说明,在实验性根尖周炎的动物模型中髓样分化因子88有表达,并随时间呈一定的表达趋势,髓样分化因子88可能参与了根尖周炎的发生及根尖牙槽骨的吸收。更多还原

【Abstract】 BACKGROUND: Studies have found that myeloid differentiation factor 88 is expressed in rat dental follicles and affects the eruption of teeth and the number of osteoclasts.OBJECTIVE: To further verify the expression of myeloid differentiation factor 88 in an experimental rat model of periapical periodontitis. METHODS: Twenty-five male Sprague-Dawley rats, 6 weeks of age, were provided by the SPF Animal Experimental Center of Dalian Medical University in China. The pulp of the first mandibular molar was exposed to establish the rat model of experimental periapical periodontitis in each rat. Endodontic pulp exposure 0 week was set as control group, while endodontic pulp exposure 1, 2, 3, 4 weeks as experimental group. Five rats were randomly selected at each time point after exposure of the endodontic pulp. Then, paraformaldehyde fixation of the mandible, decalcification, and pathological frozen sections were mode. Hematoxylin-eosin staining and immunohistochemical staining were used to observe the pathological changes of the periapical tissues. RT-PCR was used to detect the expression of myeloid differentiation factor 88 in the rat model of experimental periapical periodontitis. RESULTS AND CONCLUSION:(1) Hematoxylin-eosin staining results showed inflammatory infiltration in the apical area of the experimental group, and spread around, indicating that we successfully established the rat model of experimental periapical periodontitis.(2) Immunohistochemical staining results showed the positive expression of myeloid differentiation factor 88 in the periapical inflammation area at 1, 2, 3, 4 weeks after modeling. The positive expression of myeloid differentiation factor 88 significantly increased within 1-3 weeks, peaked at 3 weeks, but decreased at 4 weeks. There were only a small number of myeloid differentiation factor 88 positive cells in the control group.(3) RT-PCR results showed that the mRNA expression of myeloid differentiation factor 88 increased gradually from 1 week to 3 weeks, and then decreased at 4 weeks. To conclude, myeloid differentiation factor 88 is expressed in the animal model of experimental periapical periodontitis and shows a tendency of expression over time. Myeloid differentiation factor 88 may be involved in the occurrence of periapical periodontitis and the resorption of alveolar bone in periapical periodontitis.更多还原