Wang Mei, Chen Yu, Guo Zhen, Yang Changcheng, Qi Jiaomei, Fu Yujuan, Chen Zuohong, Chen Ping, Wang Ying
The Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha 410081, PR China.
The Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha 410081, PR China.
Toxicon. 2018 Dec 15;156:34-40. doi: 10.1016/j.toxicon.2018.11.002. Epub 2018 Nov 3.
Amanitin-induced apoptosis is proposed to have a significant effect on the pathogenesis of liver damage. However, few reports have focused on proteome changes induced by α-amanitin (α-AMA). Here, we evaluated changes in mitochondrial proteins of hepatocytes in response to 2 μM α-AMA, a concentration at which α-AMA-induced cell damage could be rescued at cellular level by common clinical drugs. We found 56 proteins were differentially expressed in an α-AMA-treated group. Among them, 38 proteins were downregulated and 18 were upregulated. Downregulated functional proteins included importer TOMM40, respiratory chain component cytochrome C, and metabolic enzymes of citrate acid cycle such as malate dehydrogenase, which localize on the mitochondrial outer membrane, inner membrane and matrix respectively. Immunoblot analysis showed that α-AMA decreased mitochondrial import receptor subunit TOMM40 and cytochrome c accompanied by an increase in the cytosol although their total protein levels were not affected significantly. The mitochondrial membrane potential was also destroyed by α-AMA and was restored by the clinical drug silibinin. Immunofluorescence suggested that mitochondrial morphology did not change. Taken together, our results provide further insights into the toxic mechanism of α-AMA on hepatocytes.
鹅膏毒肽诱导的细胞凋亡被认为对肝损伤的发病机制有显著影响。然而，很少有报告关注α-鹅膏毒肽（α-AMA）诱导的蛋白质组变化。在此，我们评估了肝细胞线粒体蛋白质对2μM α-AMA的反应变化，在该浓度下，常见临床药物可在细胞水平挽救α-AMA诱导的细胞损伤。我们发现56种蛋白质在α-AMA处理组中差异表达。其中，38种蛋白质下调，18种上调。下调的功能蛋白包括输入蛋白TOMM40、呼吸链成分细胞色素C以及柠檬酸循环的代谢酶，如苹果酸脱氢酶，它们分别定位于线粒体外膜、内膜和基质。免疫印迹分析表明，α-AMA降低了线粒体输入受体亚基TOMM40和细胞色素c，同时胞质溶胶增加，尽管它们的总蛋白水平没有受到显著影响。α-AMA还破坏了线粒体膜电位，临床药物水飞蓟宾可使其恢复。免疫荧光表明线粒体形态没有改变。综上所述，我们的结果为α-AMA对肝细胞的毒性机制提供了进一步的见解。
