Identification of cell aging-related biomarkers in abdominal aortic aneurysm based on bioinformatics analyses and experimental assays

Objective Abdominal aortic aneurysm (AAA) is commonly seen degenerative vascular disorder. Emerging evidence indicates that cellular aging may contribute to the progression of AAA, however its molecular mechanism in this context remains inadequately characterized. Methods This research combined bulk RNA sequencing and single-cell RNA sequencing (scRNA-seq) data sourced from the Gene Expression Omnibus (GEO) database, and incorporated 503 cell aging-related genes (CARGs). Key cells associated with cell aging were identified by single-cell analysis and multiple algorithms. Subsequently, potential biomarkers were screened through differential expression analysis and machine learning algorithms. The putative roles were disclosed using enrichment analysis and immune infiltration study. Ultimately, the expression of biomarkers was assessed in whole blood samples via reverse transcription polymerase chain reaction (RT-qPCR). Results Our findings indicated that B cells were effectively recognized as the key cells in AAA. Subsequent analyses identified RPL31, POLR2I, and SNF8 as cell aging-related biomarkers of AAA, all of which were significantly downregulated in AAA tissue and validated in blood samples. Enrichment analysis demonstrated that biomarkers might promote disease progression through inflammation and energy metabolism in AAA. Furthermore, immune microenvironment assessment revealed significant associations between biomarkers and specific immune cell, particularly M1 macrophages and regulatory T cells. Conclusion Our study identified three cell aging-related biomarkers (RPL31, POLR2I, and SNF8) in AAA, providing novel insights into AAA pathogenesis and targeted therapy.