Supplementary file 1_Integrating bioinformatics and molecular experiments to reveal the critical role of the cellular energy metabolism-related marker PLA2G1B in COPD epithelial cells.docx

BackgroundChronic obstructive pulmonary disease (COPD) is a chronic respiratory disease characterized by small airway lesions and persistent airflow limitation. Recent studies have highlighted impaired cellular energy metabolism (CEM) in COPD, although the underlying mechanisms remain incompletely understood.
Material and methodsThis research identified cell energy metabolism-related differentially expressed genes (CEM-DEGs) by collecting CEM-associated signatures from multiple public databases and integrating these markers with data from the GEO database. Subsequently, five machine learning algorithms—Boruta, Xgboost, GBM, SVM-RFE, and LASSO—were employed to screen for key variables. Gene Set Enrichment Analysis (GSEA) and immune infiltration analysis were then performed on these key CEM-DEGs. Finally, the results of the bioinformatics analysis were verified by in vitro and in vivo experiments in combination with the single-cell data analysis results.
ResultsBioinformatic analysis identified six critical markers (CYP1B1, CA3, AHRR, MGAM, PNMT, and PLA2G1B) that regulated CEM in the progression of COPD, from which a prognostic model was constructed using a nomogram with an area under the curve (AUC) of 0.814. Functional enrichment analysis further elucidated the intricate interplay between these CEM regulatory factors and key biological processes, including inflammation, oxidative stress, and epithelial-mesenchymal transition. Beyond that, both in vitro and in vivo experiments, along with single-cell data analysis, have conclusively verified the specific downregulation of PLA2G1B in epithelial cells derived from the COPD group. Notably, the knockdown of PLA2G1B in epithelial cells triggered inflammation, oxidative stress, and apoptosis.
ConclusionsThis study identified six CEM-related biomarkers (CYP1B1, CA3, AHRR, MGAM, PNMT, and PLA2G1B) in COPD and established a corresponding prognostic model. Furthermore, in vitro and in vivo experiments validated the regulatory role of PLA2G1B in epithelial cell inflammation, oxidative stress, and apoptosis, thereby elucidating the mechanism underlying CEM in COPD and potentially uncovering novel therapeutic targets for drug development.