Integration of Bioinformatics and Experiments to Identify Mitochondrial Metabolism and Immune Infiltration...

Acute lung injury (ALI) and subsequent lung fibrosis involve critical roles of mitochondrial metabolism and immune inflammation. This study identified 10 hub mitochondrial-related differentially expressed genes (MitoDEGs) linked to these conditions through integrated bioinformatics screening and protein-protein interaction analysis. Functional enrichment associated these MitoDEGs with energy conversion, oxidative stress, and fatty acid metabolism in ALI and fibrosis. Immune infiltration analysis revealed prominent M1 macrophage infiltration in ALI, with significant correlations between each hub MitoDEG and immune cells. In vivo and in vitro experiments confirmed dynamic expression changes of key MitoDEGs, including Uqcrq and Ndufb6, alongside disturbances in mitochondrial, oxidative stress, and lipid metabolism pathways. Multiplex immunohistochemistry showed increased Ndufb6-positive alveolar epithelial cells during inflammatory infiltration. Functional studies demonstrated that Ndufb6 deficiency attenuated mitochondrial fragmentation, respiratory dysfunction, and oxidative stress under inflammatory and fibrotic stimuli. Preliminary evaluation also suggested the clinical relevance of Ndufb6 and Uqcrq. These findings highlight MitoDEGs at the intersection of mitochondrial metabolism and immune response, offering new mechanistic and therapeutic insights for ALI and post-injury lung fibrosis.