The effect of plasma from septic ICU patients on healthy rat muscle mitochondria.
The effect of plasma from septic ICU patients on healthy rat muscle mitochondria.
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DOI：
10.1186/s40635-016-0093-2
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发表时间：
2016-12
影响因子：
3.5
通讯作者：
Rooyackers O
中科院分区：
文献类型：
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作者：
Grip J;Jakobsson T;Tardif N;Rooyackers O
尽管败血症导致的器官衰竭是世界范围内ICU死亡的主要原因，但与之相关的线粒体功能障碍尚不完全清楚，目前还没有证据表明两者之间存在因果关系。在这项研究中，我们研究了脓毒症血浆中的一个中心因素是否可以直接影响健康大鼠肌肉线粒体的呼吸功能。有严重脓毒症或感染性休克的ICU患者在入院24小时内被纳入，并与年龄匹配的对照组一起。血液样本被离心并立即冷冻。进行了两个试验，并使用带有Clark电极的氧气室分析线粒体呼吸。(1)分离大鼠骨骼肌线粒体，与患者或术后对照组血浆孵育30min(n = 10)。呼吸被归一化为柠檬酸合成酶活性。(2)分离大鼠通透性肌纤维，与患者和健康对照组的血浆孵育30和120min，分析线粒体呼吸(n = 10)。呼吸按湿重归一化。主要结果是状态3呼吸，对应于ADP和能量底物(苹果酸和丙酮酸)启动的最大呼吸。统计学比较采用t检验。在两个实验中，线粒体的呼吸功能在两组之间都没有发现差异。(1)脓毒症组线粒体状态3呼吸分别为19.9 ± 6.7vs.20.2 ± 8.8nmolO2 × U+CS−1 × −1。(2)与脓毒症血浆和对照血浆孵育的纤维，状态3呼吸在30min后为2.6 ± 0.3vs.2.4 ± 0.7,120min后为2.5 ± 0.4vs.2.5 ± 0.6nmolO2 × mg × W.W−1 × min−1。这些发现表明，脓毒症患者的肌肉线粒体不受血浆中某一因子的直接影响。脓毒症中线粒体功能的影响可能更多地是细胞内过程和信号的结果，例如，产生活性氧物种。
Although sepsis-induced organ failure is a major cause of death in ICU worldwide, the associated mitochondrial dysfunction is not fully characterized and there is presently no evidence of causality. In this study, we examined whether a central factor in septic plasma could directly affect respiratory function of healthy rat muscle mitochondria. ICU patients with severe sepsis or septic shock were recruited within 24 h of admission together with age-matched controls. Blood samples were centrifuged and immediately frozen. Two trials were performed, and mitochondrial respiration was analyzed using an Oxygraph chamber with a Clark-electrode. (1) Isolated mitochondria from the rat skeletal muscle were divided and incubated for 30 min with plasma from patients or postoperative controls (n = 10). Respiration was normalized for citrate synthase activity. (2) Permeabilized muscle fibers from rats were divided and incubated with plasma from patients or healthy controls, for 30 and 120 min, and analyzed for mitochondrial respiration (n = 10). Respiration was normalized for wet weight. Primary outcome was state 3 respiration, corresponding to the maximal respiration initiated by ADP and energy substrates (malate and pyruvate). T test was used for statistical comparison. No differences in respiratory function of the mitochondria were seen between the groups in either of the experiments. (1) State 3 respiration of isolated mitochondria were 19.9 ± 6.7 vs. 20.2 ± 8.8 nmol O2 × U CS−1 × min−1 for sepsis vs. control, respectively. (2) State 3 respiration for fibers incubated with septic and control plasma were after 30 min 2.6 ± 0.3 vs. 2.4 ± 0.7 and after 120 min 2.5 ± 0.4 vs. 2.5 ± 0.6 nmol O2 × mg × w.w−1 × min−1. Respiratory control ratios were good in all experiments (8.8–11.2), ensuring functioning mitochondria. These findings indicate that muscle mitochondria are not directly influenced by a factor in plasma of septic patients. The effects seen in mitochondrial function in sepsis may rather be a result of intracellular processes and signaling, such as e.g., production of reactive oxygen species.