Mitochondrial superoxide production during oxalate-mediated oxidative stress in renal epithelial cells
Mitochondrial superoxide production during oxalate-mediated oxidative stress in renal epithelial cells
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DOI：
10.1016/s0891-5849(02)00846-8
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发表时间：
2002-06-15
影响因子：
7.4
通讯作者：
Hothersall, JS
中科院分区：
文献类型：
--
作者：
Khand, FD;Gordge, MP;Hothersall, JS
肾小管中的一水草酸钙（COM）晶体是大多数肾结石的基础。由COM-细胞相互作用引起的肾小管功能障碍通过不完全理解的机制发生。我们检测了用COM（25-250 μ g/ml）处理后近端（LLC-PK 1）和远端（MDCK）肾小管上皮细胞的活性氧中间体（ROI）的产生，以确定ROI，特别是超氧化物（O-2（.-）），生产被激活，以及它是否足以诱导氧化应激。采用细胞溶质和线粒体系统的抑制剂，ROI生产的来源进行了调查。此外，还测定了细胞内谷胱甘肽（总谷胱甘肽和氧化谷胱甘肽）、能量状态（ATP）和NADH。COM处理1-24天，增加了O-2（.-）通过透化细胞中光泽精化学发光和完整细胞中二氢罗丹明荧光测量，其产量为3-6倍。使用选择性抑制剂，我们没有发现胞质生产的证据。线粒体探针，底物和抑制剂的使用表明，增加O-2（.-）生产起源于线粒体。用COM治疗降低谷胱甘肽（总的和氧化还原状态），表明持续的氧化损伤。在COM处理的细胞中，NADH的增加表明这种辅因子可能是导致O-2（.-）一代总之，COM增加线粒体O-2（.-）由上皮细胞产生，随后消耗抗氧化状态。这些变化可能有助于肾结石发展过程中报告的细胞转化。(C)2002年爱思唯尔科技有限公司
Crystals of calcium oxalate monohydrate (COM) in the renal tubule form the basis of most kidney stones. Tubular dysfunction resulting from COM-cell interactions occurs by mechanism(s) that are incompletely understood. We examined the production of reactive oxygen intermediates (ROI) by proximal (LLC-PK1) and distal (MDCK) tubular epithelial cells after treatment with COM (25-250 mug/ml) to determine whether ROI, specifically superoxide (O-2(.-)), production was activated, and whether it was sufficient to induce oxidative stress. Employing inhibitors of cytosolic and mitochondrial systems, the source of ROI production was investigated. In addition, intracellular glutathione (total and oxidized), energy status (ATP), and NADH were measured. COM treatment for 1-24 It increased O-2(.-) production 3-6-fold as measured by both lucigenin chemiluminescence in permeabilized cells and dihydrorhodamine fluorescence in intact cells. Using selective inhibitors we found no evidence of cytosolic production. The use of mitochondrial probes, substrates, and inhibitors indicated that increased O-2(.-) production originated from mitochondria. Treatment with COM decreased glutathione (total and redox state), indicating a sustained oxidative insult. An increase in NADH in COM-treated cells suggested this cofactor could be responsible for elevating O-2(.-) generation. In conclusion, COM increased mitochondrial O-2(.-) production by epithelial cells, with a subsequent depletion of antioxidant status. These changes may contribute to the reported cellular transformations during the development of renal calculi. (C) 2002 Elsevier Science Inc.