Yang Y, Zhou Y, Cheng S, Sun J L, Yao H, Ma L
School of Public Health, Xinjiang Medical University, Xinjiang, Urumqi, China.
School of Basic Medicine, Xinjiang Medical University, Xinjiang, Urumqi, China.
Genet Mol Res. 2016 Jun 24;15(2):gmr8644. doi: 10.4238/gmr.15028644.
Here, we investigated the effect of uric acid (UA) on hepatocyte mitochondria. Hepatocytes cultured in vitro were treated with varying concentrations of UA. The change in apoptotic activity was detected by flow cytometry. The DNA damage index 8-hydroxy-deoxy-guanosine (8-OHdG) and mitochondrial function indices succinate dehydrogenase (SDH), cytochrome C oxidase (CCO), and adenosine triphosphate (ATP) were detected by enzyme assays. Reactive oxygen species (ROS) accumulation was confirmed by a dichloro-dihydro-fluorescein diacetate assay. We observed an increase in apoptotic activity, ROS accumulation, and 8-OHdG activity in hepatocytes treated with UA for extended periods, indicating DNA damage; specifically, we observed a significant increase in these activities 48, 72, and 96 h after UA addition, compared to those observed at 24 h (P < 0.05). Cells treated with 30 mg/dL UA for 96 h showed a peak in apoptotic activity. We also observed a significant decrease in ATP, SDH, and CCO activities with the increase in uric acid concentration over time. Cells treated with 30 mg/dL UA for 96 h showed the highest ATP levels, while SDH and CCO activities at 48, 72, and 96 h post-UA treatment were significantly lower than those at 24 h (P < 0.01). Moreover, cells treated with 30 mg/dL UA showed a 0.02 ± 0.02 and 0.15 ± 0.01 mmol/ mg/min decrease in SDH and CCO levels after 72 h. Therefore, we concluded that high concentrations of UA may induce oxidative stress in hepatocyte mitochondria, increasing ROS production and ultimately resulting in mitochondrial damage.
在此，我们研究了尿酸（UA）对肝细胞线粒体的影响。体外培养的肝细胞用不同浓度的UA处理。通过流式细胞术检测凋亡活性的变化。通过酶法检测DNA损伤指数8-羟基脱氧鸟苷（8-OHdG）以及线粒体功能指标琥珀酸脱氢酶（SDH）、细胞色素C氧化酶（CCO）和三磷酸腺苷（ATP）。通过二氯二氢荧光素二乙酸酯检测法确认活性氧（ROS）的积累。我们观察到，长时间用UA处理的肝细胞中凋亡活性、ROS积累和8-OHdG活性增加，表明存在DNA损伤；具体而言，与24小时时观察到的情况相比，我们观察到在添加UA后48、72和96小时这些活性显著增加（P<0.05）。用30mg/dL UA处理96小时的细胞凋亡活性达到峰值。我们还观察到，随着尿酸浓度随时间增加，ATP、SDH和CCO活性显著降低。用30mg/dL UA处理96小时的细胞ATP水平最高，而在UA处理后48、72和96小时的SDH和CCO活性显著低于24小时时的活性（P<0.01）。此外，用30mg/dL UA处理的细胞在72小时后SDH和CCO水平分别下降了0.02±0.02和0.15±0.01mmol/mg/min。因此，我们得出结论，高浓度的UA可能会在肝细胞线粒体中诱导氧化应激反应，增加ROS的产生并最终导致线粒体损伤。
