Institute of Toxicology, School of Public Health, Shandong University, 44 West Wenhua Road, Jinan, Shandong 250012, PR China.
Institute of Toxicology, School of Public Health, Shandong University, 44 West Wenhua Road, Jinan, Shandong 250012, PR China; Hebei Provincial Chest Hospital, 372 North Shengli Street, Shijiazhuang, Hebei 050041, PR China.
Biochem Pharmacol. 2019 Nov;169:113643. doi: 10.1016/j.bcp.2019.113643. Epub 2019 Sep 19.
Mitochondrial dysfunction was considered as a critical event involved in acetaminophen (APAP)-induced acute liver injury. Mitophagy is a type of autophagy responsible for the selective removal of damaged mitochondria. However, the exact role and possible mechanism of mitophagy in APAP-induced hepatotoxicity remains largely unknown. In this study, C57/BL6 mice were used to establish a model of acute liver injury via intraperitoneal (i.p.) injection with different doses of APAP. Furthermore, autophagy intervention experiments were achieved by the administration of rapamycin (RAPA) or chloroquine (CQ) one hour prior to dosing 300 mg/kg APAP. The activity of serum enzymes and pathological changes of APAP-treated mice were evaluated, and the critical molecules in mitophagy and NLRP3 inflammasome pathway were determined by electron microscopy, immunoblot, immunofluorescence and real-time PCR. The results demonstrated that APAP overdose resulted in an activation of PINK1/Parkin-mediated mitophagy in mice liver. Moreover, the expression of the critical molecules in NF-kB and NLRP3 inflammasome signaling pathway were markedly increased by APAP. Our further investigation found that pretreatment with RAPA protected against APAP-induced hepatoxicity in mice. Notably, RAPA significantly inhibited the activation of NF-kB and NLRP3 inflammasome and the production of IL-1β in APAP-treated mice. By contrast, pretreatment with CQ further enhanced NLRP3 inflammasome signaling pathway. Taken together, these results indicated that activation of PINK1/Parkin-mediated mitophagy protects against APAP-induced acute liver injury in mice through inhibiting inflammasome activation. Therefore, mitophagy may represent a promising therapeutic target for APAP-induced liver injury.
线粒体功能障碍被认为是与对乙酰氨基酚（APAP）诱导的急性肝损伤有关的关键事件。自噬是一种负责选择性去除受损线粒体的自噬类型。然而，自噬在 APAP 诱导的肝毒性中的确切作用和可能的机制在很大程度上仍然未知。在这项研究中，使用 C57/BL6 小鼠通过腹腔内（i.p.）注射不同剂量的 APAP 建立急性肝损伤模型。此外，通过在给予 300mg/kg APAP 前一小时给予雷帕霉素（RAPA）或氯喹（CQ）来进行自噬干预实验。评估了血清酶的活性和 APAP 处理小鼠的病理变化，并通过电子显微镜、免疫印迹、免疫荧光和实时 PCR 确定了自噬和 NLRP3 炎性体途径中的关键分子。结果表明，APAP 过量导致小鼠肝脏中 PINK1/Parkin 介导的自噬激活。此外，APAP 明显增加了 NF-kB 和 NLRP3 炎性体信号通路中关键分子的表达。我们进一步的研究发现，RAPA 预处理可防止 APAP 诱导的小鼠肝毒性。值得注意的是，RAPA 可显著抑制 NF-kB 和 NLRP3 炎性体的激活以及 APAP 处理小鼠中 IL-1β 的产生。相比之下，CQ 的预处理进一步增强了 NLRP3 炎性体信号通路。总之，这些结果表明，PINK1/Parkin 介导的自噬的激活可通过抑制炎性体的激活来保护小鼠免受 APAP 诱导的急性肝损伤。因此，自噬可能成为治疗 APAP 诱导的肝损伤的有前途的治疗靶点。
