Intensive Care Unit, Instituto de Pesquisa Clínica Evandro Chagas, Oswaldo Cruz Foundation (Fiocruz), Rio de Janeiro, RJ, Brazil.
Crit Care Med. 2011 May;39(5):1056-63. doi: 10.1097/CCM.0b013e31820eda5c.
Increasing evidence points to the role of mitochondrial dysfunction in the pathogenesis of sepsis. Previous data indicate that mitochondrial function is affected in monocytes from septic patients, but the underlying mechanisms and the impact of these changes on the patients' outcome are unknown. We aimed to determine the mechanisms involved in mitochondrial dysfunction in peripheral blood mononuclear cells from patients with septic shock.
A cohort of patients with septic shock to study peripheral blood mononuclear cell mitochondrial respiration by high-resolution respirometry analyses and to compare with cells from control subjects.
Three intensive care units and an academic research laboratory.
Twenty patients with septic shock and a control group composed of 18 postoperative patients without sepsis or shock.
Ex vivo measurements of mitochondrial oxygen consumption were carried out in digitonin-permeabilized peripheral blood mononuclear cells from 20 patients with septic shock taken during the first 48 hrs after intensive care unit admission as well as in peripheral blood mononuclear cells from control subjects. Clinical parameters such as hospital outcome and sepsis severity were also analyzed and the relationship between these parameters and the oxygen consumption pattern was investigated.
We observed a significant reduction in the respiration specifically associated with adenosine-5'-triphosphate synthesis (state 3) compared with the control group (5.60 vs. 9.89 nmol O2/min/10(7) cells, respectively, p < .01). Reduction of state 3 respiration in patients with septic shock was seen with increased prevalence of organ failure (r = -0.46, p = .005). Nonsurviving patients with septic shock presented significantly lower adenosine diphosphate-stimulated respiration when compared with the control group (4.56 vs. 10.27 nmol O2/min/10(7) cells, respectively; p = .004). Finally, the presence of the functional F1Fo adenosine-5'-triphosphate synthase complex (0.51 vs. 1.00 ng oligo/mL/10(6) cells, p = .02), but not the adenine nucleotide translocator, was significantly lower in patients with septic shock compared with control cells.
Mitochondrial dysfunction is present in immune cells from patients with septic shock and is characterized as a reduced respiration associated to adenosine-5'-triphosphate synthesis. The molecular basis of this phenotype involve a reduction of F1Fo adenosine-5'-triphosphate synthase activity, which may contribute to the energetic failure found in sepsis.
越来越多的证据表明线粒体功能障碍在脓毒症发病机制中起作用。先前的数据表明，脓毒症患者的单核细胞的线粒体功能受到影响，但这些变化的潜在机制及其对患者预后的影响尚不清楚。我们旨在确定脓毒性休克患者外周血单个核细胞中线粒体功能障碍的相关机制。
一项脓毒性休克患者队列研究，通过高分辨率呼吸测量法分析来研究外周血单个核细胞的线粒体呼吸，并与对照组的细胞进行比较。
三个重症监护病房和一个学术研究实验室。
20 名脓毒性休克患者和 18 名术后无脓毒症或休克的对照组患者。
在重症监护病房入院后 48 小时内，对 20 名脓毒性休克患者的分离外周血单个核细胞进行细胞通透化处理，并进行体外测量线粒体耗氧量，同时测量对照组外周血单个核细胞的耗氧量。还分析了临床参数，如住院结局和脓毒症严重程度，并研究了这些参数与耗氧模式之间的关系。
与对照组相比，我们观察到与三磷酸腺苷合成相关的呼吸明显减少（状态 3：分别为 5.60 和 9.89 nmol O2/min/10(7)细胞，p <.01）。脓毒性休克患者状态 3 呼吸减少与器官衰竭的发生率增加有关（r = -0.46，p =.005）。与对照组相比，脓毒性休克非幸存者的二磷酸腺苷刺激呼吸明显降低（分别为 4.56 和 10.27 nmol O2/min/10(7)细胞，p =.004）。最后，与对照组相比，脓毒性休克患者的功能性 F1Fo 三磷酸腺苷合酶复合物（0.51 和 1.00 ng 寡霉素/mL/10(6)细胞，p =.02）的丰度显著降低，但腺嘌呤核苷酸转运蛋白的丰度没有差异。
脓毒性休克患者的免疫细胞存在线粒体功能障碍，其特征是与三磷酸腺苷合成相关的呼吸减少。这种表型的分子基础涉及 F1Fo 三磷酸腺苷合酶活性的降低，这可能导致脓毒症中的能量衰竭。
