Xu Guiping, Hao Jiandong, Wang Xiaoli, Qu Li
Department of Anesthesiology, People's Hospital of Xinjiang Uygur Autonomous Region, Urumqi 830002, Xinjiang, China.
Department of Anesthesiology, Xiongan Xuanwu Hospital, Xiongan New Area 070001, Hebei, China.
Int Immunopharmacol. 2025 Dec 3;166:115507. doi: 10.1016/j.intimp.2025.115507. Epub 2025 Sep 15.
Acute lung injury (ALI) involves severe inflammation and oxidative stress. Ferroptosis, a regulated form of cell death, and immune cell infiltration are increasingly recognized as central mechanisms in ALI.
This study integrated transcriptomic and miRNA datasets from GEO with ferroptosis-related gene sets from FerrDb. Differential expression, enrichment analyses, WGCNA, ssGSEA, and PPI network construction were applied to identify key genes. Experimental validation was performed in a murine LPS-induced ALI model using qRT-PCR, Western blotting, lung injury assessment, and ferroptosis marker analysis. In addition, a dual-luciferase reporter assay was conducted to verify the direct binding of miR-21a-5p to the EGR1 3'UTR.
Twenty-two ferroptosis-related genes were differentially expressed and enriched in inflammation and IL-17 signaling. Five key genes (IL6, IL1B, TIMP1, ATF3, and EGR1) were identified by intersecting PPI and WGCNA results. EGR1 was positively correlated with immune infiltration and validated as significantly upregulated in LPS-induced ALI. Knockdown of EGR1 mitigated ferroptosis, reduced ROS, MDA, and iron accumulation, restored GPX4, SLC7A11, and FTH1 expression, and improved lung function. Erastin, a ferroptosis inducer, reversed the protective effects. A miRNA-mRNA network suggested mmu-miR-21a-5p regulates EGR1, and dual-luciferase reporter assays further confirmed the direct binding of miR-21a-5p to the EGR1 3'UTR.
EGR1 is a central regulator linking ferroptosis and immune cell infiltration in LPS-induced ALI. Targeting the miR-21a-5p-EGR1 axis may offer novel diagnostic and therapeutic strategies for acute lung injury.
急性肺损伤（ALI）涉及严重的炎症和氧化应激。铁死亡是一种受调控的细胞死亡形式，免疫细胞浸润越来越被认为是ALI的核心机制。
本研究将来自GEO的转录组和miRNA数据集与来自FerrDb的铁死亡相关基因集进行整合。应用差异表达、富集分析、加权基因共表达网络分析（WGCNA）、单样本基因集富集分析（ssGSEA）和蛋白质-蛋白质相互作用（PPI）网络构建来鉴定关键基因。在小鼠脂多糖（LPS）诱导的ALI模型中，使用定量逆转录聚合酶链反应（qRT-PCR）、蛋白质印迹法、肺损伤评估和铁死亡标志物分析进行实验验证。此外，进行双荧光素酶报告基因测定以验证miR-21a-5p与早期生长反应蛋白1（EGR1）3'非翻译区（UTR）的直接结合。
22个铁死亡相关基因在炎症和白细胞介素-17信号通路中差异表达并富集。通过交叉PPI和WGCNA结果鉴定出5个关键基因（白细胞介素6、白细胞介素1β、金属蛋白酶组织抑制因子1、活化转录因子3和EGR1）。EGR1与免疫浸润呈正相关，并在LPS诱导的ALI中被验证为显著上调。敲低EGR1可减轻铁死亡，减少活性氧（ROS）、丙二醛（MDA）和铁积累，恢复谷胱甘肽过氧化物酶4（GPX4）、溶质载体家族7成员11（SLC7A11）和铁蛋白重链1（FTH1）的表达，并改善肺功能。铁死亡诱导剂埃拉斯汀可逆转这些保护作用。一个miRNA- mRNA网络表明小鼠miR-21a-5p调节EGR1，双荧光素酶报告基因测定进一步证实了miR-21a-5p与EGR1 3'UTR的直接结合。
EGR1是连接LPS诱导的ALI中铁死亡和免疫细胞浸润的核心调节因子。靶向miR-21a-5p-EGR1轴可能为急性肺损伤提供新的诊断和治疗策略。
