Davis Christopher A, Nick Harry S, Agarwal Anupam
*Department of Biochemistry and Molecular Biology, Department of Medicine, and Department of Neuroscience, University of Florida, Gainesville, Florida.
J Am Soc Nephrol. 2001 Dec;12(12):2683-2690. doi: 10.1681/ASN.V12122683.
Cisplatin is a potent chemotherapeutic agent that is used to treat many human malignancies. Unfortunately, in addition to side effects such as ototoxicity, anaphylaxis, and bone marrow suppression, a significant percentage of patients receiving cisplatin develop severe nephrotoxicity. Mitochondrial dysfunction that is mediated via the generation of reactive oxygen species has been implicated in the pathogenesis of cisplatin-induced renal injury. To address the mechanism, it was hypothesized that overexpression of antioxidant enzymes, such as mitochondria-localized manganese superoxide dismutase (MnSOD) or mitochondria-targeted catalase (mito-Cat), would be cytoprotective in cisplatin-induced cell injury. To this end, human MnSOD or a mito-Cat vector were stably transfected into human embryonic kidney 293 cells. Cells that overexpressed MnSOD exhibited significantly less cell rounding and detachment compared with both mito-Cat and vector controls after exposure to 20 microM cisplatin. Cell injury as assessed by DNA fragmentation and annexin V binding assays was significantly decreased in the cells that overexpressed MnSOD compared with vector alone and mito-Cat. In addition, elevated levels of MnSOD were strongly associated with increased clonogenic potential after cisplatin challenge. Thus, overexpression of MnSOD, and not catalase, protects against cisplatin-induced renal epithelial cell injury. These results demonstrate the importance of reactive oxygen species in the mechanism that underlies cisplatin-induced renal injury and specifically implicate the superoxide radical, and not hydrogen peroxide, as the mediator.
顺铂是一种强效化疗药物，用于治疗多种人类恶性肿瘤。不幸的是，除了耳毒性、过敏反应和骨髓抑制等副作用外，接受顺铂治疗的患者中有相当比例会出现严重的肾毒性。通过活性氧生成介导的线粒体功能障碍与顺铂诱导的肾损伤发病机制有关。为了探究其机制，研究人员提出假设，即抗氧化酶（如线粒体定位的锰超氧化物歧化酶（MnSOD）或线粒体靶向过氧化氢酶（mito-Cat））的过表达在顺铂诱导的细胞损伤中具有细胞保护作用。为此，将人MnSOD或mito-Cat载体稳定转染到人胚肾293细胞中。与mito-Cat和载体对照相比，在暴露于20 microM顺铂后，过表达MnSOD的细胞表现出明显更少的细胞变圆和 detachment。与单独的载体和mito-Cat相比，通过DNA片段化和膜联蛋白V结合试验评估的细胞损伤在过表达MnSOD的细胞中显著降低。此外，在顺铂攻击后，MnSOD水平的升高与克隆形成潜力的增加密切相关。因此，MnSOD而非过氧化氢酶的过表达可保护细胞免受顺铂诱导的肾上皮细胞损伤。这些结果证明了活性氧在顺铂诱导的肾损伤机制中的重要性，并特别表明超氧阴离子而非过氧化氢是介导因子。
