Abstract Body: Atherosclerosis, characterized by fibro-fatty plaque accumulation in the arterial wall, remains a leading cause of mortality in the US. Coronary artery calcification (CAC) marks advanced disease and is associated with dysregulation of the extracellular matrix (ECM), plaque vulnerability, and adverse cardiovascular outcomes. While clinically relevant, the precise cell-specific molecular mechanisms driving histologically defined CAC remain incompletely defined. Here, we performed bulk transcriptomic and matrisome proteomic profiling of healthy and atherosclerotic coronary artery segments (n=84 individuals) with varying stages of calcification.

Sample calcification-status classification was based on histological staining using von Kossa. Differential expression (DE) analyses were conducted independently for each modality, followed by integrative cross-omic analyses to identify concordant gene–protein signatures in CAC. In calcified arteries, 500 DE genes and 410 matrisome-associated proteins were significantly altered. Cross-omic integration revealed a significant set of 48 upregulated and 23 downregulated gene–protein pairs (r=0.41, p=2x10-16). Upregulated pairs showed enrichment for pathways related to cell adhesion, migration, inflammation, and immune activation; downregulated pairs were associated with smooth muscle cell identity and contraction. Consistently, markers including APOE, CEMIP, CTSD, and S100A9 were upregulated in advanced calcified lesions. Notably, established markers of vascular calcification and osteogenic differentiation, including SPP1, H1-5, and CLEC11A and CRTAC1, were also identified.

Ongoing analyses will integrate patient-matched ATAC-seq to infer altered upstream gene regulatory networks driving vascular remodeling and single-cell based deconvolution approaches will be applied to define cell-specific mechanisms. The current multi-omic analysis reveals coordinated relevant molecular remodeling in calcified human coronary arteries and identifies regulatory pathways consistent with advanced atherosclerosis and vascular calcification. New modalities’ integration and cell-type deconvolution will highlight cell-type specific mechanisms with translational potential in CAC.