Single-cell and spatial transcriptomics uncovers the role of senescent vascular cells in pathological arterial remodeling during murine atherosclerosis

Studying cardiovascular senescence is crucial for understanding disease-related changes in the cardiovascular system and their impact on health and disease. To systematically investigate the heterogeneity of senescent vascular cells in atherosclerosis, we employed the senescence reporter mouse p16tdTomato+/-, overexpressed PCSK9 and fed a high-fat diet (HFD) to induce atherosclerosis, and treated them with the senolytic drug ABT-737. Whole-aorta, single-cell RNA-sequencing (scRNA-seq) and Gene Set Enrichment Analysis (GSEA) using the SenMayo panel uncovered 10 cell clusters displaying senescent features, although not ‘classical’ senescence markers, that were reduced by treatment with ABT-737. Unbiased subclustering revealed subsets of cells increasing by HFD and reduced by ABT-737 treatment that expressed unique transcripts Spp1, Ctsb, and Tnfrsf11b mRNAs. Spatial analysis of these RNAs identified senescent cells in the cap and core of brachiocephalic arteries from atherosclerotic mice. Our results uncover a vascular-specific transcriptomic signature that may be exploited for therapeutic targeting in age-related vascular diseases.