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.