自噬相关蛋白LC3Av1和LC3B在大鼠牙髓炎中的表达研究

目的 研究自噬相关蛋白LC3Av1和LC3B在大鼠实验性牙髓炎组织中的表达。方法 30只8周龄SD大鼠左侧下颌第一磨牙开髓，封入大肠埃希菌LPS（5 μg/μL）棉球，玻璃离子封闭髓腔。分别于开髓后0、6、12、24和48 h处死大鼠，分离下颌骨。组织学处理后，HE染色观察牙髓组织炎症状况，免疫组织化学染色SP法检测LC3Av1和LC3B的表达及分布。结果 正常牙髓组织中LC3Av1和LC3B少量表达。实验组中，LC3Av1在12、24和48 h时表达量较0、6 h时显著增高，差异具有统计学意义（P<0.01）；LC3B在6、12 h时表达量较0、24和48 h时增高，差异具有统计学意义（P<0.05）；两种蛋白表达分布均集中于成牙本质细胞及多细胞层中的成纤维细胞。结论 自噬相关蛋白LC3Av1和LC3B在牙髓组织中的表达随炎症发展增加，提示自噬作用可能与牙髓炎的发生发展相关。

Expression of autophagy-associated proteins LC3Av1 and LC3B in induced rat pulpitis

Objective To investigate the expression of LC3Av1 and LC3B in induced rat pulpitis．Methods The pulps of left mandibular first molars of thirty 8-week-old SD rats were exposed to E. coli LPS（5 μg/μL）cotton wool ball，then the cavities were sealed with glass ionomer cements．The rats were randomly sacrificed at 0 h，6 h，12 h，24 h and 48 h respectively，and their lower jaws were isolated．The expressions of LC3Av1 and LC3B in pulp were analyzed by using immunohistochemical staining．Results The expression of LC3Av1 was higher in pulpitis than that in normal dental pulp（P＜0.01），and the expression of LC3B was higher in pulpitis at 6 h，12 h and 48 h than at other time points（P＜0.05）．The expressions of the two proteins mainly distributed in the odontoblasts and the fibroblasts in multiple cell layer．Conclusion The expression of LC3Av1 and LC3B in dental pulp increases along with the development of inflammation， which suggests that autophagy may be associated with the development of pulpitis．