Department of Cardiothoracic Surgery, Children's Hospital of Nanjing Medical University, Nanjing, China.
Department of General surgery and otorhinolaryngology, Children's Hospital of Nanjing Medical University, Nanjing, China.
J Surg Res. 2020 Sep;253:8-17. doi: 10.1016/j.jss.2019.12.052. Epub 2020 Apr 16.
Cytochrome P450 epoxygenase 2J2 (CYP2J2) metabolizes arachidonic acid to epoxyeicosatrienoic acids, which exert anti-inflammatory effects and alleviate oxidative stress in the cardiovascular system. Our previous work revealed that CYP2J2 is expressed in pulmonary artery endothelial cells. It was therefore hypothesized that CYP2J2 overexpression may prevent lung ischemia/reperfusion injury (LIRI) in 3-week-old C57BL/6 mice during deep hypothermic low flow (DHLF). This study aimed to establish whether CYP2J2 protects against LIRI and the mechanisms of CYP2J2 overexpression during DHLF in mice. The aim of this study was to explore the effects of DHLF on lung tissue in mice and to find out the regularity of this process, so as to provide theoretical data for lung tissue protection in children undergoing this process in clinic.
A 3-week-old C57BL/6 mouse model was used to mimic LIRI conditions during DHLF by clamping the left pulmonary artery and left main bronchus for 120 min, followed by reperfusion for 2 h. The body temperature of the mice was maintained between 18°C and 19°C to induce DHLF.
During DHLF, lung ischemia/reperfusion increased the left lung wet/dry weight, the left lung weight/body weight ratio, the protein concentration in bronchoalveolar lavage fluid, and the concentration of proinflammatory mediators in the lungs, including interleukin (IL)-1, IL-8, and necrosis factor (NF)-α, and decreased the concentration of the anti-inflammatory mediator IL-10. Furthermore, activation of NF-κB p65 and degradation of IKBα were remarkably increased in lung tissues after ischemia/reperfusion. The CYP2J2 overexpression group showed the opposite results (P < 0.05), and p-Akt1 and p-GSK-3β expression were significantly higher in the CYP2J2 overexpression group (P < 0.05). Moreover, the changes in IL-1, IL-8, tumor necrosis factor-α, IL-10, p-Akt1, p-GSK-3β, NF-κB p65, and IKBα were reversed in the Akt1 gene heterozygous knockout group, and lung damage was significantly higher in the Akt1 gene heterozygous knockout group than in the CYP2J2 overexpression group. CYP2J2 overexpression can protect against LIRI, whereas Akt1 gene heterozygous knockout in mice can abolish this protective effect.
CYP2J2 overexpression can protect against LIRI by activating the P13K/Akt/GSK-3β/NF-kB signaling pathway during DHLF. Thus, changing CYP2J2 expression can be a novel strategy for the prevention and treatment of LIRI during DHLF.
细胞色素 P450 加单氧酶 2J2（CYP2J2）将花生四烯酸代谢为环氧化物二十碳三烯酸，从而发挥抗炎作用并减轻心血管系统中的氧化应激。我们之前的工作表明 CYP2J2 在肺动脉内皮细胞中表达。因此，假设 CYP2J2 过表达可能会防止深低温低流量（DHLF）期间 3 周龄 C57BL/6 小鼠的肺缺血/再灌注损伤（LIRI）。本研究旨在确定 CYP2J2 是否对 LIRI 具有保护作用，以及 CYP2J2 在 DHLF 期间过表达的机制。本研究的目的是探讨 DHLF 对小鼠肺组织的影响，找出这一过程的规律，为临床中进行该过程的儿童肺组织保护提供理论数据。
使用 3 周龄 C57BL/6 小鼠模型通过夹闭左肺动脉和左主支气管 120 分钟来模拟 DHLF 期间的 LIRI 条件，随后再灌注 2 小时。将小鼠的体温维持在 18°C 至 19°C 之间以诱导 DHLF。
在 DHLF 过程中，肺缺血/再灌注增加了左肺湿/干重、左肺重量/体重比、支气管肺泡灌洗液中的蛋白浓度以及肺中促炎介质的浓度，包括白细胞介素（IL）-1、IL-8 和坏死因子（NF）-α，并降低了抗炎介质 IL-10 的浓度。此外，缺血/再灌注后肺组织中 NF-κB p65 的激活和 IKBα 的降解明显增加。CYP2J2 过表达组则表现出相反的结果（P<0.05），并且 CYP2J2 过表达组中的 p-Akt1 和 p-GSK-3β 表达明显升高（P<0.05）。此外，Akt1 基因杂合敲除组中 IL-1、IL-8、肿瘤坏死因子-α、IL-10、p-Akt1、p-GSK-3β、NF-κB p65 和 IKBα 的变化被逆转，并且 Akt1 基因杂合敲除组的肺损伤明显高于 CYP2J2 过表达组。CYP2J2 过表达可以通过在 DHLF 期间激活 P13K/Akt/GSK-3β/NF-kB 信号通路来预防 LIRI，而 Akt1 基因杂合敲除可消除这种保护作用。
CYP2J2 过表达可通过在 DHLF 期间激活 P13K/Akt/GSK-3β/NF-kB 信号通路来预防 LIRI。因此，改变 CYP2J2 的表达可能是预防和治疗 DHLF 期间 LIRI 的一种新策略。
