Department of Emergency, The Second Hospital of Hebei Medical University, Shijiazhuang, 050000, People's Republic of China.
Translational Medicine Research Center, Medical Innovation Research Division and Fourth Medical Center of the Chinese PLA General Hospital, Beijing, 100048, People's Republic of China.
Cell Death Dis. 2021 Sep 4;12(9):834. doi: 10.1038/s41419-021-04122-8.
Ferroptosis is a nonapoptotic form of programmed cell death triggered by the accumulation of reactive oxygen species (ROS) depended on iron overload. Although most investigations focus on the relationship between ferroptosis and cancer, neurodegenerative diseases, and ischemia/reperfusion injury, research on ferroptosis induced by immune-related inflammatory diseases, especially sepsis, is scarce. Sestrin2 (Sesn2), a highly evolutionary and stress-responsive protein, is critically involved in defense against oxidative stress challenges. Upregulated expression of Sesn2 has been observed in preliminary experiments to have an antioxidative function in the context of an inflammatory response. Nevertheless, the underlying function of Sesn2 in inflammation-mediated ferroptosis in the immune system remains uncertain. The current study aimed to demonstrate the protective effect of Sesn2 on ferroptosis and even correlations with ferroptosis and the functions of ferroptotic-dendritic cells (DCs) stimulated with lipopolysaccharide (LPS). The mechanism underlying DCs protection from LPS-induced ferroptosis by Sesn2 was further explored in this study. We found that the immune response of DCs assessed by co-stimulatory phenotypes was gradually enhanced at the peak time of 12 h upon 1 μg/ml LPS stimulation while ferroptosis in DCs treated with LPS at 24 h was significantly detected. LPS-induced ferroptosis showed a suppressive impact on DCs in phenotypic maturation, which was conversely relieved by the ferroptotic inhibitor. Compared with wild-type (WT) mice, DCs in genetic defective mice of Sesn2 (Sesn2) exhibited exacerbated ferroptosis. Furthermore, the protective effect of Sesn2 on ferroptosis was noticed to be associated with the ATF4-CHOP-CHAC1 pathway, eventually exacerbating ferroptosis by degrading of glutathione. These results indicate that Sesn2 can suppress the ferroptosis of DCs in sepsis by downregulating the ATF4-CHOP-CHAC1 signaling pathway, and it might play an antioxidative role.
铁死亡是一种依赖于铁过载的由活性氧(ROS)积累引发的非凋亡性程序性细胞死亡形式。尽管大多数研究集中在铁死亡与癌症、神经退行性疾病和缺血/再灌注损伤之间的关系,但对于免疫相关炎症性疾病(特别是败血症)引起的铁死亡的研究却很少。Sesn2(Sesn2)是一种高度进化和应激反应性蛋白,在抵御氧化应激挑战中起着至关重要的作用。初步实验表明,Sesn2 的上调表达在炎症反应中具有抗氧化功能。然而,Sesn2 在免疫系统中炎症介导的铁死亡中的潜在功能尚不确定。本研究旨在证明 Sesn2 对铁死亡的保护作用,甚至与铁死亡和脂多糖(LPS)刺激的铁死亡树突状细胞(DCs)的功能相关。本研究进一步探讨了 Sesn2 保护 DCs 免受 LPS 诱导的铁死亡的机制。我们发现,在 LPS 刺激 1μg/ml 时,12 小时达到峰值,此时通过共刺激表型评估的 DC 免疫反应逐渐增强,而在 LPS 处理的 DCs 中 24 小时检测到明显的铁死亡。LPS 诱导的铁死亡对表型成熟的 DCs 有抑制作用,而铁死亡抑制剂则缓解了这种作用。与野生型(WT)小鼠相比,Sesn2 基因缺陷型(Sesn2)小鼠的 DCs 铁死亡加剧。此外,Sesn2 对铁死亡的保护作用与 ATF4-CHOP-CHAC1 通路有关,最终通过谷胱甘肽的降解加剧铁死亡。这些结果表明,Sesn2 可以通过下调 ATF4-CHOP-CHAC1 信号通路抑制败血症中 DCs 的铁死亡,发挥抗氧化作用。