Baumgart Bethany R, Gray Katherine L, Woicke Jochen, Bunch Roderick T, Sanderson Thomas P, Van Vleet Terry R
Department of Toxicology, Drug Safety Evaluation, Bristol-Myers Squibb, 4401 Highway 62 East, Mount Vernon, IN 47620, USA.
Department of Toxicology, Drug Safety Evaluation, Bristol-Myers Squibb, 4401 Highway 62 East, Mount Vernon, IN 47620, USA.
Toxicol Appl Pharmacol. 2016 Dec 1;312:26-33. doi: 10.1016/j.taap.2015.10.007. Epub 2015 Oct 23.
Mitochondrial toxicity can be difficult to detect as most cells can tolerate reduced activity as long as minimal capacity for function is maintained. However, once minimal capacity is lost, apoptosis or necrosis occurs quickly. Identification of more sensitive, early markers of mitochondrial toxicity was the objective of this work. Rotenone, a mitochondrial complex I inhibitor, and 3-nitropropionic acid (3-NP), a mitochondrial complex II inhibitor, were administered daily to male Sprague-Dawley rats at subcutaneous doses of 0.1 or 0.3mg/kg/day and intraperitoneal doses of 5 or 10mg/kg/day, respectively, for 1week. Samples of kidney, skeletal muscle (quadriceps femoris), and serum were collected for analysis of mitochondrial DNA (mtDNA) copy number and microRNA (miRNA) expression patterns. MtDNA was significantly decreased with administration of rotenone at 0.3mg/kg/day and 3-NP at 5 and 10mg/kg/day in the quadriceps femoris and with 3-NP at 10mg/kg/day in the kidney. Additionally, rotenone and 3-NP treatment produced changes to miRNA expression that were similar in direction (i.e. upregulation, downregulation) to those previously linked to mitochondrial functions, such as mitochondrial damage and biogenesis (miR-122, miR-202-3p); regulation of ATP synthesis, abolished oxidative phosphorylation, and loss of membrane potential due to increased reactive oxygen species (ROS) production (miR-338-5p, miR-546, miR-34c); and mitochondrial DNA damage and depletion (miR-546). These results suggest that miRNAs may be sensitive biomarkers for early detection of mitochondrial toxicity.
线粒体毒性可能难以检测，因为只要维持最低限度的功能能力，大多数细胞就能耐受活性降低。然而，一旦失去最低限度的功能能力，细胞凋亡或坏死就会迅速发生。本研究的目的是确定更敏感的线粒体毒性早期标志物。鱼藤酮是一种线粒体复合物I抑制剂，3-硝基丙酸（3-NP）是一种线粒体复合物II抑制剂，分别以0.1或0.3mg/kg/天的皮下剂量和5或10mg/kg/天的腹腔注射剂量，每天给雄性Sprague-Dawley大鼠给药1周。收集肾脏、骨骼肌（股四头肌）和血清样本，用于分析线粒体DNA（mtDNA）拷贝数和微小RNA（miRNA）表达模式。在股四头肌中，以0.3mg/kg/天的剂量施用鱼藤酮以及以5和10mg/kg/天的剂量施用3-NP，以及在肾脏中以10mg/kg/天的剂量施用3-NP后，mtDNA显著减少。此外，鱼藤酮和3-NP处理导致miRNA表达发生变化，其变化方向（即上调、下调）与先前与线粒体功能相关的变化相似，如线粒体损伤和生物发生（miR-122、miR-202-3p）；ATP合成的调节、氧化磷酸化的废除以及由于活性氧（ROS）产生增加导致的膜电位丧失（miR-338-5p、miR-546、miR-34c）；以及线粒体DNA损伤和耗竭（miR-546）。这些结果表明，miRNA可能是早期检测线粒体毒性的敏感生物标志物。
