Th17相关细胞因子在大鼠实验性根尖周炎表达的研究

目的辅助性T细胞17（Th17）是-种CD4阳性T细胞新亚群，本研究探讨Th17相关细胞因子与根尖周炎的炎症反应及牙槽骨破坏的关系。方法选取5周龄雄性Wistar大鼠，实验组用球钻将下颌第1磨牙开髓，根管锉清理牙髓，髓腔暴露于口腔中，14d后断颈处死。以未开髓的上颌第1磨牙作为对照组。取上下颌骨，采用Micro—CT观察根尖病损的形成情况；实验组和对照组标本均为6例，标本固定、脱钙，冰冻切片、组织学方法观察根尖病损的特点，采用抗CD68和抗TCRαβ的单克隆抗体进行免疫组化；用酶组织化学染色（TRAP染色）进行破骨细胞染色；实验组和对照组根尖组织提取总RNA，RT-PCR及荧光实时定量PCR方法定量检测根尖组织中Th17相关细胞因子IL-17、IL-23、IL-β、IL-6、TGF—β，以及破骨细胞分化因子RANKL的mRNA表达情况。结果Micro．CT显示，14d实验组有明显的根尖病损形成；组织学结果表明，实验组均存在根尖脓肿，有大量中性粒细胞、CD68阳性的巨噬细胞和散在的TCRctl3阳性T细胞浸润；病损骨面有较多的TRAP阳性破骨细胞，表明有活跃的骨吸收；RT—PCR及实时定量PCR结果显示，实验组根尖组织中Th17相关细胞因子IL-17、IL-23、IL1β、IL-6，及破骨细胞分化因子RANKL的mRNA均显著高于对照组，而TGF-β无显著性变化。结论Th17相关细胞因子在实验性根尖周炎中均有高表达，提示它们可能参与炎症过程和骨破坏。

Expression of Th17-related cytokines in induced rat periapical lesions

Objective To evaluate the expression of Th17-related cytokines in induced rat periapical lesions.Methods Male Wistar rats of 5-week-old (n=12) were used in this study.After the access cavity preparation,pulp tissues in the lower first molars were removed and the pulp cavities were left open to oral environment.Rats were sacrificed at 14 days after pulpectomy,and the lower and upper jaws were extracted.Upper jaws were used for control.Half of the samples served for immunohistochemical study,and the other hal...