Ji Ran, Chen Weiwei, Wang Yuming, Gong Fangchen, Huang Shunwei, Zhong Ming, Liu Zhaojun, Chen Ying, Ma Li, Yang Zhitao, Qu Hongping, Mao Enqiang, Chen Erzhen
Department of Emergency, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Department of Critical Care Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Shock. 2021 May 1;55(5):640-648. doi: 10.1097/SHK.0000000000001576.
Evidence implying that metabolism reprogramming plays an important role in the regulation of sepsis is increasing; however, whether it has a similar role in septic organ dysfunction remains unclear. Here, we provide evidence to support a new role of uncoupling protein-2 (UCP2)-regulated Warburg effect, i.e., aerobic glycolysis, in promoting mitochondrial injury in the kidney.
To imitate sepsis condition, male C57BL/6 mice were operated by the cecal ligation puncture in vivo, whereas a normal human kidney cell line (HK-2) was treated with lipopolysaccharide in vitro. UCP2 small interfering RNA pretreatment was performed to knock down UCP2 expression in vitro. The glycolysis metabolite was detected by liquid chromatography/tandem mass spectrometry in vivo and detected by commercial kits in vitro. Oxidative phosphorylation level and glycolysis level were monitored by measuring the oxygen consumption rate (indicative of respiration) and extracellular acidification rate (indicative of glycolysis) in vitro. Exogenous lactate was supplied to stimulate HK-2 cells and indicators of mitochondrial dysfunction were also assessed.
Aerobic glycolysis is enhanced in septic tubular epithelial cells, and the glycolysis inhibitor 2-deoxyglucose can partially restore mitochondrial membrane potential and decrease the reactive oxygen species production. With the knockdown of UCP2, the aerobic glycolysis level upregulates, and mitochondrial injury increases.
These results provide insights on a new mechanism of metabolic regulation of mitochondrial injury and the importance of targeting aerobic glycolysis for the treatment of septic acute kidney injury.
越来越多的证据表明，代谢重编程在脓毒症的调节中起重要作用；然而，其在脓毒症器官功能障碍中是否具有类似作用仍不清楚。在此，我们提供证据支持解偶联蛋白2（UCP2）调节的瓦伯格效应，即有氧糖酵解，在促进肾脏线粒体损伤中的新作用。
为模拟脓毒症状态，对雄性C57BL/6小鼠进行盲肠结扎穿刺术，而在体外用人正常肾细胞系（HK-2）进行脂多糖处理。进行UCP2小干扰RNA预处理以在体外敲低UCP2表达。通过液相色谱/串联质谱法在体内检测糖酵解代谢物，并在体外通过商业试剂盒进行检测。通过测量体外氧消耗率（指示呼吸）和细胞外酸化率（指示糖酵解）来监测氧化磷酸化水平和糖酵解水平。提供外源性乳酸以刺激HK-2细胞，并评估线粒体功能障碍指标。
脓毒症肾小管上皮细胞中的有氧糖酵解增强，糖酵解抑制剂2-脱氧葡萄糖可部分恢复线粒体膜电位并减少活性氧的产生。随着UCP2的敲低，有氧糖酵解水平上调，线粒体损伤增加。
这些结果为线粒体损伤的代谢调节新机制以及靶向有氧糖酵解治疗脓毒症急性肾损伤的重要性提供了见解。
