BACKGROUND: Role of autophagy in pulpitis, periapical periodontitis and alveolar bone destruction and the underling mechanisms have not been fully elucidated. OBJECTIVE: To investigate the expression of autophagy-related protein light chain 3B in human pulpitis and periapical periodontitis, in order to explore the rule of autophagy. METHODS: The healthy first premolar or surgically removed third premolar was selected from the patients undergoing orthodontics after their consent informs. The dental pulp cells were treated with 1 mg/L lipopolysaccharide for 0, 6, 12, 24 and 48 hours to induce inflammation. The expression of light chain 3B in normal and lipopolysaccharide-stimulated dental pulp cells was detected by western blot assay. The dotted accumulation of light chain 3B was observed by immunofluorescence. The expression level of light chain 3B in specimens of human chronic periapical periodontitis tissues was tested by real-time RT-PCR. RESULTS AND CONCLUSION: The expression of light chain 3B in dental pulp cells stimulated by lipopolysaccharide for 6, 12, 24 and 48 hours was higher than that in normal dental pulp cells. The expression of light chain 3B increased with time, and peaked at 24 hours. Dotted accumulation of light chain 3B increased with lipopolysaccharide simulation time prolonged. The expression level of light chain 3B in specimens of human chronic periapical periodontitis tissues was higher than that in normal periapical tissues. These results indicate that the expression of light chain 3B is increased in human pulpitis and periapical periodontitis, and morphology also shows an increase of autophagy, suggesting that autophagy may be associated with the occurrence and development of pulpitis and periapical periodontitis.%背景:自噬在牙髓炎、根尖周炎及其引起的牙槽骨破坏中的作用和明确机制尚未完全阐明.目的:研究自噬相关蛋白微管相关蛋白1轻链3 (LC3) B在人牙髓炎及根尖周炎中的表达, 以初步探讨自噬发挥的作用.方法:经患者知情同意后选取临床因正畸新鲜拔除的健康第1前磨牙或外科完整拔除无龋坏的健康第3磨牙.使用1 mg/L脂多糖刺激牙髓细胞, 作用时间分别为0, 6, 12, 24, 48 h, 使其引起致炎反应.Western blot法检测正常及脂多糖刺激的人牙髓细胞中微管相关蛋白1轻链3B的表达水平;细胞免疫荧光染色观察微管相关蛋白1轻链3B点状聚集情况;Real-timeRT-PCR法检测人慢性根尖周炎病损组织中微管相关蛋白1轻链3B的表达水平.结果与结论:①脂多糖刺激6, 12, 24, 48 h后的牙髓细胞中微管相关蛋白1轻链3B的表达高于正常牙髓细胞, 且Ⅱ型微管相关蛋白1轻链3B的表达随刺激时间的延长而增高, 其中24h达到高峰;②微管相关蛋白1轻链3B点状聚集随脂多糖刺激时间延长而增多;③微管相关蛋白1轻链3B在人慢性根尖周炎病损组织中的表达高于正常根尖周组织;④结果说明, 自噬相关蛋白微管相关蛋白1轻链3B在人牙髓炎及根尖周炎中的表达增高, 形态学亦显示自噬活动增强, 提示自噬作用可能与牙髓炎及根尖周炎的发生发展相关.
展开▼
