Department of Dentistry, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chia-Yi, Taiwan.
School of Dentistry, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
Int Endod J. 2018 Feb;51 Suppl 2:e125-e145. doi: 10.1111/iej.12782. Epub 2017 May 23.
To determine the expressions of hypoxia-related [hypoxia-inducible transcription factors (HIF)-1α, BCL2/adenovirus E1B 19 kDa protein-interacting protein 3 (BNIP3) and phospho-adenosine monophosphate activated protein kinase (pAMPK)] and autophagy-related [microtubule-associated protein 1 light chain 3 (LC3), beclin-1 (BECN-1), autophagy-related gene (Atg)5-12, and p62] proteins in human inflammatory periapical lesions.
Fifteen samples of radicular cysts (RCs) and 21 periapical granulomas (PGs), combined with 17 healthy dental pulp tissues, were examined. Enzyme-linked immunosorbent assay (ELISA) was used to detect interleukin (IL)-1β cytokine; immunohistochemical (IHC) and Western blot (WB) analyses were employed to examine autophagy-related and hypoxia-related proteins. Transmission electron microscopy (TEM) was used to explore the ultrastructural morphology of autophagy in periapical lesions. Nonparametric Kruskal-Wallis tests and Mann-Whitney U-tests were used for statistical analyses.
ELISA revealed a significantly higher (P < 0.001) IL-1β expression in periapical lesions than in normal pulp tissue. Immunoscores of IHC expressions of pAMPK, HIF-1α, BNIP3, BECN-1 and Atg5-12 proteins in periapical lesions were significantly higher (P < 0.001) (except BECN-1) than those in normal pulp tissue. The results of IHC studies were largely compatible with those of WB analyses, where significantly higher (P < 0.05) expressions of hypoxia-related and autophagy-related proteins (except BECN-1, p62 and LC3II in WB analyses) in periapical lesions were noted as compared to normal pulp tissue. Upon TEM, ultrastructural double-membrane autophagosomes and autolysosomes were observed in PGs and RCs.
Autophagy associated with hypoxia may play a potential causative role in the development and maintenance of inflamed periapical lesions.
确定缺氧相关[缺氧诱导转录因子（HIF）-1α、BCL2/腺病毒 E1B 19kDa 蛋白相互作用蛋白 3（BNIP3）和磷酸腺苷激活蛋白激酶（pAMPK）]和自噬相关[微管相关蛋白 1 轻链 3（LC3）、beclin-1（BECN-1）、自噬相关基因（Atg）5-12 和 p62]蛋白在人炎症性根尖周病变中的表达。
检查了 15 例根尖囊肿（RCs）和 21 例根尖肉芽肿（PGs）样本，结合 17 例健康牙髓组织。采用酶联免疫吸附试验（ELISA）检测白细胞介素（IL）-1β细胞因子；免疫组织化学（IHC）和 Western blot（WB）分析检测自噬相关和缺氧相关蛋白。透射电子显微镜（TEM）用于探索根尖病变中自噬的超微结构形态。采用非参数 Kruskal-Wallis 检验和 Mann-Whitney U 检验进行统计学分析。
ELISA 显示根尖病变中 IL-1β表达明显高于正常牙髓组织（P<0.001）。根尖病变中 pAMPK、HIF-1α、BNIP3、BECN-1 和 Atg5-12 蛋白的 IHC 表达免疫评分明显高于（P<0.001）（除 BECN-1 外）正常牙髓组织。免疫组化研究结果与 WB 分析结果基本一致，在根尖病变中，缺氧相关和自噬相关蛋白（除 WB 分析中的 BECN-1、p62 和 LC3II 外）的表达明显高于正常牙髓组织（P<0.05）。在 TEM 下，在 PGs 和 RCs 中观察到具有双层膜的自噬体和自噬溶酶体。
与缺氧相关的自噬可能在炎症性根尖周病变的发生和维持中发挥潜在的因果作用。
