Xu Feibo, Liu Yanfen, Zhao Hansong, Yu Kaiyuan, Song Miao, Zhu Yanzhu, Li Yanfei
College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, China.
College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, China; Liaoning Agricultural College, Yingkou 115009, China.
J Inorg Biochem. 2017 Sep;174:55-62. doi: 10.1016/j.jinorgbio.2017.04.016. Epub 2017 Apr 20.
Aluminum (Al) is known to exert hepatotoxicity. However, the mechanisms mostly are unclear. Liver is a metabolism organ that maintains the energy level and structural stability of body, mitochondria are the main sites of energy metabolism, thus, we hypothesized that mitochondrial energy metabolism disorder contributes to liver dysfunction in aluminum chloride (AlCl) treatment rat. To verify the hypothesis, forty male Wistar rats were randomly allocated and orally exposed to 0, 64mg/kg, 128mg/kg and 256mg/kg body weight AlCl in drinking water for 120days, respectively. We found that AlCl exposure reduced the electron transport chain complexes I-V activities and adenosine triphosphate (ATP) level, as well as disturbed mitochondrial DNA transcript, presenting as the inhibited mRNA expressions of NADH dehydrogenase 1, NADH dehydrogenase 2, cytochrome b, cytochrome c oxidase subunit 1, cytochrome c oxidase subunit 3 and ATP synthase 6, indicating that AlCl exposure disturbs the mitochondrial energy metabolism, and it caused an increase in liver enzymes (Aspartate aminotransferase and Alanine aminotransferase) and histopathological lesions. Additionally, we found that reactive oxygen species accumulation and decreased superoxide dismutase activity in mitochondria, and increased 8-Hydroxydeoxyguanosine levels in mitochondrial DNA, demonstrating AlCl exposure promotes mitochondrial oxidative stress, which may be a contributing factor to mitochondrial energy metabolism disorder and liver dysfunction. The study displayed that mitochondria are the potential target of liver damage induced by AlCl, providing considerable direction for the prevention and clinical intervention of liver diseases.
已知铝(Al)具有肝毒性。然而,其机制大多尚不清楚。肝脏是维持机体能量水平和结构稳定性的代谢器官,线粒体是能量代谢的主要场所,因此,我们推测线粒体能量代谢紊乱在氯化铝(AlCl)处理的大鼠肝脏功能障碍中起作用。为验证这一假设,将40只雄性Wistar大鼠随机分组,分别通过饮用水口服给予0、64mg/kg、128mg/kg和256mg/kg体重的AlCl,持续120天。我们发现,AlCl暴露降低了电子传递链复合体I-V的活性和三磷酸腺苷(ATP)水平,扰乱了线粒体DNA转录,表现为NADH脱氢酶1、NADH脱氢酶2、细胞色素b、细胞色素c氧化酶亚基1、细胞色素c氧化酶亚基3和ATP合酶6的mRNA表达受到抑制,这表明AlCl暴露扰乱了线粒体能量代谢,并导致肝酶(天冬氨酸转氨酶和丙氨酸转氨酶)升高和组织病理学损伤。此外,我们发现线粒体中活性氧积累、超氧化物歧化酶活性降低,线粒体DNA中8-羟基脱氧鸟苷水平升高,表明AlCl暴露促进了线粒体氧化应激,这可能是线粒体能量代谢紊乱和肝脏功能障碍的一个促成因素。该研究表明线粒体是AlCl诱导肝损伤的潜在靶点,为肝脏疾病的预防和临床干预提供了重要指导。