Role of Apoptosis and Immune Infiltration in Chronic Atrophic Gastritis from Bioinformatics Analysis

Abstract Chronic atrophic gastritis (CAG) is usually caused by Helicobacter pylori infection. It is increasingly being recognized as a precancerous lesion that progresses to gastric carcinoma. This study was designed to explore the role of apoptosis and immunity in CAG caused by H. pylori via bioinformatic analysis and to explore the key genes and molecular mechanisms involved in CAG. Gene expression datasets were downloaded from the Gene Expression Omnibus database. Gene set enrichment analysis (GSEA) and weighted correlation network analysis (WGCNA) were employed to identify the main signaling pathways of CAG. Apoptosis and immune-related significant genes (API-DEGs) were determined based on differentially expressed genes. The Cytoscape software was used to visualize and identify hub genes. The Gene Ontology and Kyoto Encyclopedia of Genes and Genomes databases were used for the pathway enrichment analysis of API-DEGs. The ImmuCellAI algorithm was applied to evaluate immune infiltration patterns. Finally, the miRNA–mRNA–TF regulatory network was built. Findings indicated that apoptosis and immunity are the two most relevant processes involved in H. pylori-associated atrophic gastritis. Further, we identified 45 API-DEGs including 10 hub genes. This study provides base-line data to study the etiological mechanisms of atrophic gastritis and develop therapeutic strategies in the future.