Single-cell sequencing combined with transcriptome sequencing to reveal the molecular mechanisms related to integrated stress responses in atherosclerosis.

BACKGROUND: Atherosclerosis is a chronic inflammatory vascular disease in which cellular stress and immune imbalance are central drivers. Although the integrated stress response (ISR) is increasingly implicated, its specific roles and key ISR-related genes in atherosclerosis remain unclear. METHODS: We integrated single-cell RNA sequencing data from human carotid plaques with bulk microarray datasets to identify ISR-related genes linked to disease progression. ISR activity was compared across vascular and immune cell types. Differentially expressed genes in monocytes were screened using Lasso regression and random forest algorithms. Functional enrichment, immune infiltration, and regulatory network analyses were performed. Gene expression was validated in an atherosclerosis mouse model. RESULTS: Six ISR-related genes (FABP4, HERPUD1, RHOB, SERPINB9, MYL6 and XBP1) were identified in atherosclerotic monocytes. These genes were enriched in inflammatory and immune-metabolic pathways, including NF kappa B, Toll-like receptor and interferon responses. Immune infiltration patterns showed close associations with B cells, T cells and macrophages. In vivo validation confirmed altered expression of all six genes, with SERPINB9 showing the most significant increase. CONCLUSION: This study delineates the ISR-related molecular features in atherosclerosis and demonstrates their regulatory roles in immune infiltration and cellular stress pathways, providing potential molecular targets for future therapeutic intervention.