Comprehensive Bioinformatics Evaluation within the Left Atrial Appendage from Individuals with Atrial Fibrillation to Enhance the Comprehension of Atrial Fibrillation-Related Thrombus Development

To investigate differentially expressed genes and their potential functions in left atrial appendage tissues from patients with atrial fibrillation through integrated bioinformatics analysis, providing a theoretical basis for the molecular mechanisms underlying AF-related thrombus formation. Two gene expression datasets, GSE79768 and GSE115574, were obtained from the GEO database. A total of 14 left atrial appendage samples from AF patients and 16 from sinus rhythm controls were included. Differentially expressed genes were screened using the limma package. Gene Ontology functional annotation and KEGG pathway enrichment analyses were performed using DAVID and KOBAS databases, and a protein-protein interaction network was constructed using the STRING database. A total of 96 common differentially expressed genes were identified, including 69 upregulated and 27 downregulated genes. GO analysis indicated that these genes were predominantly enriched in biological processes such as cell surface, antigen processing and presentation, and immune response. KEGG analysis suggested significant enrichment of differentially expressed genes in the phagosome pathway, as well as signaling pathways related to Staphylococcus aureus infection and tuberculosis. PPI network analysis identified 20 hub genes, including TYROBP, CD53, and CTSS. Differentially expressed genes in left atrial appendage tissues of AF patients are primarily involved in immune-inflammatory responses and phagosome-related pathways. These molecules may participate in the regulatory processes of thrombus formation under AF conditions.