基于生物信息学筛选急性肺损伤(acute lung injury, ALI)/急性呼吸窘迫综合征(acute respiratory distress syndrome, ARDS)相关铁死亡枢纽基因，分析与免疫分型关系，为早期ALI/ARDS诊断和治疗提供新靶点。

采用基因表达综合(gene expression omnibus, GEO)数据库下载GSE216943、GSE263867和GSE236215数据集，使用R语言软件分析差异表达基因(differentially expressed genes, DEGs)，进行基因本体论(gene ontology, GO)、京都基因与基因组百科全书(Kyoto encyclopedia of genes and genomes, KEGG)通路分析。采用LASSO回归和随机森林算法筛选ALI/ARDS相关铁死亡枢纽基因。绘制受试者工作特征曲线(receiver operating characteristic curve, ROC)分析基因诊断价值，使用CIBERSORT分析免疫浸润。

GSE216943中筛选出281个DEGs(39个下调，242个上调)，GSE263867中筛选出969个DEGs(449个下调，520个上调)。两个数据集220个交集DEGs中32个下调，188个上调。GO分析显示，基因参与脂多糖反应、细胞因子信号、白细胞迁移等免疫和炎症相关过程。LASSO回归分析筛选出5个关键基因Cybb、Hmox1、Cp、Ⅱ1b、Fth1。随机森林分析筛选出6个关键基因Cybb、Lcn2、Il1b、Cxcl2、Hmox1、Timp1。韦恩图显示ALI/ARDS中3个铁死亡枢纽基因Cybb、Hmox1、Ⅱ1b。ROC曲线分析显示，Ⅱ1b、Hmox1和Cybb在GSE216943和GSE263867中曲线下面积(area under curve, AUC)为1。验证集GSE236215中Ⅱ1b和Hmox1的AUC为1，Cybb的AUC为0.969。豆荚图显示ALI/ARDS组中Ⅱ1b、Hmox1和Cybb表达升高。CIBERSORT算法分析11个ALI/ARDS样本与对照组免疫细胞组成差异显著。免疫相关性分析显示，初始B细胞、浆细胞、巨噬细胞M2、静息树突状细胞和静息肥大细胞等免疫细胞浸润水平与枢纽基因Ⅱ1b、Hmox1和Cybb呈负相关，记忆B细胞、巨噬细胞M0、巨噬细胞M1、活化肥大细胞和中性粒细胞与枢纽基因呈正相关。活化NK细胞和单核细胞与Ⅱ1b和Hmox1呈负相关，辅助T滤泡细胞与Cybb呈正相关。

Cybb、Hmox1和Ⅱ1b为ALI/ARDS相关铁死亡枢纽基因，与巨噬细胞极化和T细胞反应相关，可为ALI/ARDS分子诊断和靶向治疗提供参考。

To identify key ferroptosis-related hub genes associated with acute lung injury (ALI) and acute respiratory distress syndrome (ARDS), explore their relationship with immune response and inflammation, and validate their diagnostic efficacy, providing new targets for early diagnosis and treatment.

Gene expression datasets GSE216943, GSE263867, and GSE236215 were downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were analyzed using R software, and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed. Ferroptosis-related genes were integrated to identify ALI/ARDS-associated hub genes, followed by LASSO regression and random forest algorithm analysis. Receiver operating characteristic (ROC) curves were used to evaluate the diagnostic efficacy of the genes, and immune infiltration was analyzed using CIBERSORT.

In dataset GSE216943, 281 DEGs were identified (39 downregulated, 242 upregulated), while GSE263867 revealed 969 DEGs (449 downregulated, 520 upregulated). There were 220 intersecting DEGs between the two datasets, comprising 32 downregulated and 188 upregulated genes. GO analysis indicated involvement in immune and inflammatory processes such as lipopolysaccharide response, cytokine signaling, and leukocyte migration. LASSO regression identified 5 key genes: Cybb, Hmox1, Cp, Ⅱ1b, and Fth1. Random forest analysis highlighted 6 key genes: Cybb, Lcn2, Ⅱ1b, Cxcl2, Hmox1, and Timp1. Venn diagram illustrated Cybb, Hmox1, and Ⅱ1b as central hub genes in ALI/ARDS. ROC curve analysis showed AUCs of 1 for Ⅱ1b, Hmox1, and Cybb in both GSE216943 and GSE263867. Validation set GSE236215 demonstrated AUCs of 1 for Ⅱ1b and Hmox1, and 0.969 for Cybb. Beanplot depicted elevated expression of Ⅱ1b, Hmox1, and Cybb in the ALI/ARDS group. The CIBERSORT algorithm revealed significant differences in immune cell composition between 11 ALI/ARDS and 11 control samples. Immune correlation analysis indicated negative correlations of memory B cells, M2 macrophages, resting dendritic cells, and resting mast cells with hub genes Ⅱ1b, Hmox1, and Cybb, while positive correlations were observed with naive B cells, M0 macrophages, M1 macrophages, activated mast cells, and neutrophils. Activated NK cells and monocytes showed negative correlations with Ⅱ1b and Hmox1, while follicular helper T cells positively correlated with Cybb.

This study identifies Cybb, Hmox1, and Ⅱ1b as pivotal ferroptosis-related hub genes in ALI/ARDS. These genes are closely associated with macrophage polarization and T cell responses, may serve as promising biomarkers and therapeutic targets for the molecular diagnosis and treatment of ALI/ARDS.