Department of Microbiology and Immunology, Penn State Cancer Institute, Penn State Milton S. Hershey Medical Center, Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033, USA.
Toxicol Sci. 2010 Nov;118(1):119-27. doi: 10.1093/toxsci/kfq230. Epub 2010 Jul 28.
Liver disease is responsible for more than 42,000 deaths yearly. Elevated hepatic iron levels have been shown to play a role in chronic liver diseases including hereditary hemochromatosis, thalassemia, and chronic hepatitis C, whereas acetaminophen (APAP) is the leading cause of acute liver failure. The goal of this study was to determine whether increased hepatic iron affects APAP-induced cytotoxicity, reactive oxygen species (ROS) production, and/or mitochondrial dysfunction in primary mouse hepatocytes (PMHs) that are differentiated and have gap junctional intracellular integrity, properties associated with hepatocytes in vivo and important for conducting toxicant studies. Treatment of PMHs with the iron donor 3,5,5-trimethyl-hexanoyl ferrocene (TMHF) caused an elevation in ferritin, reduction in transferrin receptor 1, and accumulation of hemosiderin, but TMHF treatment alone did not induce ROS or cause mitochondrial dysfunction. The threshold APAP dose that induced PMH cell death after TMHF treatment of PMHs was lower than in the absence of TMHF. In addition, treatment with the iron chelator deferoxamine (DFO) protected from APAP and resulted in a higher threshold dose being needed to induce cell death. We also showed that after TMHF treatment, APAP induced ROS and mitochondrial dysfunction at earlier time points than treatment with APAP alone; treatment with DFO increased the length of time required for APAP to induce ROS and mitochondrial dysfunction; and treatment with DFO, subsequent to TMHF, partially protected against TMHF-potentiated APAP injury. We conclude that iron potentiates the effects of APAP on cytotoxicity, ROS production, and mitochondrial dysfunction in PMHs.
肝脏疾病每年导致超过 42000 人死亡。肝内铁水平升高已被证明在慢性肝病中起作用，包括遗传性血色素沉着症、地中海贫血和慢性丙型肝炎，而对乙酰氨基酚（APAP）是急性肝衰竭的主要原因。本研究的目的是确定增加的肝铁是否会影响原代小鼠肝细胞（PMH）中 APAP 诱导的细胞毒性、活性氧（ROS）产生和/或线粒体功能障碍，这些 PMH 分化并具有间隙连接细胞内完整性，这是与体内肝细胞相关的特性，对进行毒物研究很重要。用铁供体 3,5,5-三甲基己酰基二茂铁（TMHF）处理 PMH 会导致铁蛋白升高、转铁蛋白受体 1 减少和血铁黄素积累，但 TMHF 单独处理不会诱导 ROS 或导致线粒体功能障碍。在没有 TMHF 的情况下，TMHF 处理 PMH 后诱导 PMH 细胞死亡的 APAP 剂量阈值低于没有 TMHF 的情况。此外，用铁螯合剂去铁胺（DFO）处理可防止 APAP 并导致需要更高的阈值剂量才能诱导细胞死亡。我们还表明，在 TMHF 处理后，APAP 诱导 ROS 和线粒体功能障碍的时间早于单独用 APAP 处理的时间；DFO 处理增加了 APAP 诱导 ROS 和线粒体功能障碍所需的时间；DFO 处理后，TMHF 部分减轻了 TMHF 增强的 APAP 损伤。我们得出结论，铁增强了 APAP 在 PMH 中对细胞毒性、ROS 产生和线粒体功能障碍的作用。
