Kidney Disease Center, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, China.
Department of Nephrology, HwaMei Hospital, University of Chinese Academy of Sciences, Ningbo, Zhejiang, China.
Biomed Res Int. 2020 Feb 22;2020:6097516. doi: 10.1155/2020/6097516. eCollection 2020.
We here investigated the impact of mechanical ventilation (MV) time on ferroptosis in a rat renal ischemia/reperfusion injury (IRI) model. Thirty-two male adult Sprague Dawley rats were divided into four groups ( = 8/group): the sham group, IRI group, IRI+MV-4 h group, and IRI+MV-12 h group. Rats in the IRI group were subjected to 45 min bilateral renal ischemia. Rats in the IRI+MV groups were additionally mechanically ventilated with tracheal intubation after 45 min bilateral renal ischemia. Morphological changes associated with kidney injury and ferroptosis were assessed by hematoxylin and eosin staining and electron microscopy. Levels of the central regulator of ferroptosis, glutathione peroxidase 4 (GPX4), and lipid peroxidation markers 4-hydroxynonenal (4HNE) and superoxide dismutase 2 (SOD2) were determined in the kidney tissue by western blotting. Glutathione (GSH) levels were assessed in the serum and kidney homogenate. Scr levels in the IRI+MV-12 h group were significantly higher than those in the sham, IRI, and IRI+MV-4 h groups (all < 0.001). Electron microscopy revealed the most pronouncedly abnormal mitochondrial morphology, suggestive of ferroptosis, in the IRI+MV-12 h group. The GPX4 and SOD2 protein levels progressively decreased in the following order: sham group > IRI group > IRI+MV-4 h group > IRI+MV-12 h group ( < 0.05 for all comparisons). By contrast, the 4HNE levels progressively increased in the kidney, with the highest values in the IRI+MV-12 h group ( < 0.05, vs. the IRI group and vs. the IRI+MV-4 h group). Further, the GSH levels in the serum and kidney homogenates were significantly reduced in the IRI+MV-12 h group ( < 0.01, vs. IRI group and vs. the IRI+MV-4 h group). A significant positive correlation was observed between the serum and kidney GSH levels ( = 0.542, = 0.03). These observations suggested that prolonged MV may exacerbate renal function failure, already initiated by IRI, by ferroptosis. Depletion of GSH may contribute to this effect, which requires further investigation.
我们在此研究了机械通气（MV）时间对大鼠肾缺血再灌注损伤（IRI）模型中铁死亡的影响。32 只雄性成年 Sprague Dawley 大鼠被分为四组（每组 8 只）：假手术组、IRI 组、IRI+MV-4 h 组和 IRI+MV-12 h 组。IRI 组大鼠接受 45 分钟双侧肾缺血。在 45 分钟双侧肾缺血后，IRI+MV 组大鼠通过气管插管进行机械通气。通过苏木精和伊红染色和电子显微镜评估与肾损伤和铁死亡相关的形态变化。通过 Western blot 测定肾组织中铁死亡的中央调节因子谷胱甘肽过氧化物酶 4（GPX4）和脂质过氧化标志物 4-羟壬烯醛（4HNE）和超氧化物歧化酶 2（SOD2）的水平。通过血清和肾匀浆评估谷胱甘肽（GSH）水平。IRI+MV-12 h 组的 Scr 水平明显高于假手术组、IRI 组和 IRI+MV-4 h 组（均<0.001）。电子显微镜显示，IRI+MV-12 h 组的线粒体形态最明显异常，提示铁死亡。GPX4 和 SOD2 蛋白水平依次降低，顺序为：假手术组>IRI 组>IRI+MV-4 h 组>IRI+MV-12 h 组（所有比较均<0.05）。相比之下，肾组织中的 4HNE 水平逐渐升高，IRI+MV-12 h 组的水平最高（与 IRI 组和 IRI+MV-4 h 组相比，均<0.05）。此外，IRI+MV-12 h 组血清和肾匀浆中的 GSH 水平显著降低（与 IRI 组和 IRI+MV-4 h 组相比，均<0.01）。血清和肾 GSH 水平之间存在显著正相关（ = 0.542， = 0.03）。这些观察结果表明，长时间的 MV 可能通过铁死亡加重已经由 IRI 引发的肾功能衰竭。GSH 的耗竭可能促成了这一效应，这需要进一步研究。
