Baek Su Mi, Kwon Chae Hwa, Kim Jae Ho, Woo Jae Suk, Jung Jin Sup, Kim Yong Keun
Department of Psychology, College of Medicine, Pusan National University, South Korea.
J Lab Clin Med. 2003 Sep;142(3):178-86. doi: 10.1016/S0022-2143(03)00111-2.
Reactive oxygen species (ROS) have been suggested as important mediators of cisplatin-induced acute renal failure in vivo. However, our previous studies have shown that cisplatin-induced cell death in vitro could not be prevented by scavengers of hydrogen peroxide and hydroxyl radical in rabbit renal cortical slices. This discrepancy may be attributed to differential roles of ROS in necrotic and apoptotic cell death. We therefore examined, in this study, the roles of ROS in necrosis and apoptosis induced by cisplatin in primary cultured rabbit proximal tubule. Cisplatin induced necrosis at high concentrations over a few hours and apoptosis at much lower concentrations over longer periods. Necrosis induced by high concentration of cisplatin was prevented by a cell-permeable superoxide scavenger (tiron), hydrogen peroxide scavengers (catalase and pyruvate), and antioxidants (Trolox and deferoxamine), whereas hydroxyl radical scavengers (dimethythiourea and thiourea) did not affect the cisplatin-induced necrosis. However, apoptosis induced by lower concentration of cisplatin was partially prevented by tiron and hydroxyl radical scavengers but not by hydrogen peroxide scavengers and antioxidants. Cisplatin-induced apoptosis was mediated by the signaling pathway that is associated with cytochrome c release from mitochondria and caspase-3 activation. These effects were prevented by tiron and dimethylthiourea but not by catalase. Dimethylthiourea produced a significant protection against cisplatin-induced acute renal failure, and the effect was associated with an inhibition of apoptosis. These results suggest that hydrogen peroxide is involved in the cisplatin-induced necrosis, whereas hydroxyl radical is responsible for the cisplatin-induced apoptosis. The protective effects of hydroxyl radical scavengers are associated with an inhibition of cytochrome c release and caspase activation.
活性氧（ROS）被认为是顺铂在体内诱导急性肾衰竭的重要介质。然而，我们之前的研究表明，在兔肾皮质切片中，过氧化氢和羟自由基清除剂无法预防顺铂在体外诱导的细胞死亡。这种差异可能归因于ROS在坏死性和凋亡性细胞死亡中的不同作用。因此，在本研究中，我们检测了ROS在原代培养的兔近端小管中顺铂诱导的坏死和凋亡中的作用。顺铂在数小时内高浓度诱导坏死，在更长时间内低得多的浓度诱导凋亡。高浓度顺铂诱导的坏死可被细胞可渗透的超氧化物清除剂（钛铁试剂）、过氧化氢清除剂（过氧化氢酶和丙酮酸）和抗氧化剂（生育三烯酚和去铁胺）预防，而羟自由基清除剂（二甲基硫脲和硫脲）不影响顺铂诱导的坏死。然而，低浓度顺铂诱导的凋亡可被钛铁试剂和羟自由基清除剂部分预防，但不能被过氧化氢清除剂和抗氧化剂预防。顺铂诱导的凋亡由与细胞色素c从线粒体释放和半胱天冬酶-3激活相关的信号通路介导。这些作用可被钛铁试剂和二甲基硫脲预防，但不能被过氧化氢酶预防。二甲基硫脲对顺铂诱导的急性肾衰竭产生显著保护作用，且该作用与凋亡抑制有关。这些结果表明，过氧化氢参与顺铂诱导的坏死，而羟自由基负责顺铂诱导的凋亡。羟自由基清除剂的保护作用与细胞色素c释放和半胱天冬酶激活的抑制有关。
