Oxygen consumption rates and oxygen concentration in Molt-4 cells and their mtDNA depleted (ρ0) mutants
Oxygen consumption rates and oxygen concentration in Molt-4 cells and their mtDNA depleted (ρ0) mutants
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DOI：
10.1016/s0006-3495(03)74944-3
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发表时间：
2003-02-01
影响因子：
3.4
通讯作者：
Swartz, H
中科院分区：
文献类型：
--
作者：
Shen, JA;Khan, N;Swartz, H
呼吸缺陷细胞系被越来越多地用于阐明线粒体的作用和了解线粒体遗传疾病的病理生理学。我们研究了野生型（WT）和线粒体DNA （mtDNA）耗尽（rho(0)） Molt-4细胞的耗氧率和氧浓度。野生型Molt-4细胞的耗氧率适中，rho(0)细胞的耗氧率明显降低。PCMB抑制WT和rho(0)细胞的耗氧速率，而氰化钾仅降低WT Molt-4细胞的耗氧速率。甲萘醌亚硫酸氢钠（MSB）增加了两种细胞系的耗氧率，而CCCP（羰基氰化物间氯苯腙）只刺激WT Molt-4细胞的耗氧率。用MSB刺激后，在WT和rho(0)细胞中均观察到超氧自由基加合物。PCMB对该加合物的形成有抑制作用，而氰化钾对其无抑制作用。这些结果表明，MSB诱导的活性氧（ROS）至少部分是通过线粒体独立途径产生的。在WT Molt-4细胞中，观察到细胞外区室和细胞内区室之间存在氧梯度，CCCP和MSB刺激细胞时，氧梯度进一步增加。结果与我们早期的发现一致，表明这种氧梯度可能是在适当条件下大多数或所有细胞系统中发现的普遍现象。
Respiratory deficient cell lines are being increasingly used to elucidate the role of mitochondria and to understand the pathophysiology of mitochondrial genetic disease. We have investigated the oxygen consumption rates and oxygen concentration in wild-type (WT) and mitochondrial DNA (mtDNA) depleted (rho(0)) Molt-4 cells. Wild-type Molt-4 cells have moderate oxygen consumption rates, which were significantly reduced in the rho(0) cells. PCMB (p-chloromercurobenzoate) inhibited the oxygen consumption rates in both WT and rho(0) cells, whereas potassium cyanide decreased the oxygen consumption rates only in WT Molt-4 cells. Menadione sodium bisulfite (MSB) increased the oxygen consumption rates in both cell lines, whereas CCCP (carbonyl cyanide m-chlorophenylhydrazone) stimulated the oxygen consumption rates only in WT Molt-4 cells. Superoxide radical adducts were observed in both WT and rho(0) cells when stimulated with MSB. The formation of this adduct was inhibited by PCMB but not by potassium cyanide. These results suggest that the reactive oxygen species (ROS) induced by MSB were at least in part produced via a mitochondrial independent pathway. An oxygen gradient between the extra- and intracellular compartments was observed in WT Molt-4 cells, which further increased when cells were stimulated by CCCP and MSB. The results are consistent with our earlier findings suggesting that such oxygen gradients may be a general phenomenon found in most or all cell systems under appropriate conditions.