Department of Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, P.R. China.
Department of Cardiovascular Medicine, The First Affiliated Hospital of Nanchang University, Nanchang of Jiangxi, P.R. China.
Int J Hyperthermia. 2022;39(1):977-986. doi: 10.1080/02656736.2022.2094476.
Acute lung injury (ALI) is a common complication of heat stroke (HS) and a direct cause of death. However, the mechanism underlying ALI following HS remains unclear.
To investigate whether ferroptosis is involved in HS-ALI. We established a HS model of mice and mouse lung epithelial-2 cells (MLE-2). The severity of lung injury was measured by H&E staining, the wet-to-dry lung weight ratio, and Transmission electron microscopy. Potential markers of ferroptosis Fe, malondialdehyde (MDA), hydroxynonenal (4-HNE) and lipid peroxidation were detected. The percentages of cell death and viability induced by HS were assessed by LDH and CCK8 assays. SLC7A11, ACSL4, GPX4, SIRT1, p53, and p53 K382 acetylation levels were measured by Western blot.
The administration of ferroptosis inhibitor ferrostatin-1(Fer-1) could significantly ameliorate lung injury, inhibiting levels of MDA and 4-HNE, and ameliorating HS-induced increased ACSL4, decreased SLC7A11 and GPX4, suggesting ferroptosis was involved in HS-induced ALI and . Moreover, SIRT1 expression decreased, and p53 K382 acetylation levels increased in MLE-2 cells. Activation of SIRT1 could improve lung epithelial ferroptosis caused by HS ang . Besides, the activation of SIRT1 could significantly reduce the p53 K382 acetylation levels, suggesting that activation of SIRT1 could prevent ferroptosis inhibiting p53 acetylation.
These findings substantiate the vital role of the SIRT1/p53 axis in mediating ferroptosis in HS-ALI, suggesting that targeting SIRT1 may represent a novel therapeutic strategy to ameliorate ALI during HS.
急性肺损伤(ALI)是中暑(HS)的常见并发症,也是导致死亡的直接原因。然而,HS 后 ALI 的发生机制尚不清楚。
探讨铁死亡是否参与 HS-ALI。我们建立了小鼠和小鼠肺上皮-2 细胞(MLE-2)的 HS 模型。通过 H&E 染色、肺湿重/干重比和透射电镜观察来测量肺损伤的严重程度。检测铁死亡的潜在标志物铁、丙二醛(MDA)、4-羟基壬烯醛(4-HNE)和脂质过氧化。通过 LDH 和 CCK8 测定评估 HS 诱导的细胞死亡和活力百分比。通过 Western blot 测定 SLC7A11、ACSL4、GPX4、SIRT1、p53 和 p53 K382 乙酰化水平。
铁死亡抑制剂 ferrostatin-1(Fer-1)的给药可显著改善肺损伤,抑制 MDA 和 4-HNE 水平,并改善 HS 诱导的 ACSL4 增加、SLC7A11 减少和 GPX4 减少,表明铁死亡参与了 HS 诱导的 ALI。此外,MLE-2 细胞中 SIRT1 表达减少,p53 K382 乙酰化水平增加。SIRT1 的激活可改善 HS 引起的肺上皮铁死亡。此外,SIRT1 的激活可显著降低 p53 K382 乙酰化水平,表明 SIRT1 的激活可通过抑制 p53 乙酰化来防止铁死亡。
这些发现证实了 SIRT1/p53 轴在介导 HS-ALI 中铁死亡中的重要作用,表明靶向 SIRT1 可能代表改善 HS 期间 ALI 的一种新的治疗策略。